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■M^l.
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, F7-S-
A TEXT-BOOK
OKE AND STONE MINING.
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Stan&art» Morlts
MANAGERS OF MINES & COLLIERIES, MINING ENGINEERS,
SURVEYORS, AND METALLURGISTS.
PBACTICAL GEOLOGY (AIDS IN). ByQ. A.J. Colm, F.Q.5., Prof.
of Qtaloa, 1107*1 Collnn of BcKiwt, DnMlo. With nniiurou IlliNtntiaiu.
COAL MIKING. B7 H. W. Huohee, F.G.S., Aooc. B.S.U:. With 490
' IllnUntloiu. SicoBD EsinoB. 1S>.
MINE SURVEYING. Br B. H. Bbouob, F.G.S., fbnnerl; Instroctor of
Kiiia Bnmjliig, SojmI Saluol oT MIdm. Foobtm Enttior, Illuitntad, 7i. 6d.
TRAVERSE TABLES ; oompated to I'bnt PIbom Deoimali for every
WdbM or Aa*l«ap tolODofDUtwn. Bt Bioiilmd Llotd QDion, Anlhor.
iHd Suntjct for tha UoTUnoWDt of Stw Sootb Wilw ud TlclotU. Txima
NEW METALLURGICAL SERIES
W. 0. EOBERTS-AUSTEN, C.B., F.R8.,
L INTBODUCTION TO THE STUDY OF HETALLDBGY. By the
2. GOLD. By T. K. Bo«e, Amoc. B.S.H., B.Sc., Amttont-ABMyer of
tha Kojil Hint. Sla.
8. COPPEB. Bj Thoi. Gibb, Asmo. K.S.M., F.I.C.
4v IBON AND STEEL. B7 Tbob. Tubhbb, Amoc. B.S.U., F.LC.
6. XETALLDBGICAL MACHINERY. B; U. J>iiEiKB,Wli.Se., Asmc
B.S.II., A(w>cH.lD>I.CE., o(Uw UoialMiat.
6. ALLOYS. B; the Editob.
V Otlur VcJomai la PrapanUm.
LoNDOK : CHARLES GRIFFIN & CO., Ltd., Euteb Stbekt, Stiand.
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A TEXT-BOOK
OP
ORE AND STONE
MINING.
BY
C. LE NEVE FOSTER, B.A., D.Sc., F.RS.,
WITH FRONTISPIECE AND 716 rLLUSTRATIONa
LONDON:
CHAELES GRIFFIN & COMPANY, LIMITED,
EXETEE 8TEEET, STRAND.
1894.
ZAU rithU ntttvtd.2
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PREFACE.
The object of my text-book is to aaaiBt students in acqniriug
a knowledge of the art of mining. Books and lectures are
not intended to take the place of practical teaching at mines ;
but they render the training more thorough and complete
in many ways : they serve to explain the principles of the
art, to solve difficulties which perplex the beginner, to
surest matters which he should observe, to tell him oE
things beyond his ken, and to supply him with a system for
arranging his ideas methodically.
It will be seen bj my numerous references that I have not
hesitated to avail myself of very varied sources of informa-
tion, and that I have taken care to avoid dwelling too much
upon English examples.
As far as possible I have set my face against the indis-
criminate use of the local slang of any particular district.
Mining is quite difficult enough without introducing unneces-
sary technical terms, and if words which are generally under-
stood by English-speaking nations will express our ideas
clearly, it is far better to employ them than to fall back upon
provincialisms which vary from one district to another; on
the oUier hand, certain expressions may sometimes recommend
themselves by reason of their pithiness, for adoption into our
tongue.
Within the limits of this preface it is impossible to name
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all the persons to whom I am indebted for matter contained
in this volume. Many useful facts have been picked up
while visiting mines at home and abroad, and in the course
of conversation with my colleagues. I therefore gladly
record my obligations to mining men generally, whom I
have invariably found ready to give me the benefit of their
I have to thank the Council of the Institution of Civil
Engineers, the Council of the Institution of Mechanical
Engineers, the Editors of Engineering and of the Engineering
and Mining Journal, M. Paulin Arrault, Mr. Augustus Bowie,
Mr. William Galloway, Messrs. Letcher and Michell, and
others, for permission to reproduce some of their figures. A
few of the blocks have been borrowed from Mr. Hughes'
"Text-book of Coal Mining."
Mr, J. G. Lawn and Mr. L. H. Cooke have given me
valuable assistance in coiTecting proofs, and the former espe-
cially has saved me from some of the pitfalls which beset the
path of an author who is passing a book through the press.
The very full index prepared for me by Mr. S. W. Price will
facilitate reference to my pages.
LliAKDUDHO, NOBTH WALBS,
Jtwj, 1894.
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GENERAL CONTENTS.
iHTEODUCnOK.
Chaitek I. — Mode
OP OOCUEBEKCE OF MlNXBAU.
fAOH
rAct
OudfioKtion . . .
3
Roldore .
4>
TabnUi Depodts .
5
Qraphito .
50
I. Beds . .
5
OypMim .
St>
3. Velni or Lodu .
■1
I<4 . . . .
5«
Hm«u-. . .
Iron ore . . .
51
"^Fi :
Lead ore . .
ss
20
MaDg.MH.OM. .
57
Ambet
Hica . .
58
AuUmoDj .
Natural Gae
If
Araenio .
31
Kitt»to of Sod* . .
Oiokerite . .
63
AqihUt . . .
Petroloam. . .
6!
BM7t«a . .
=3
Pboapbate of Lime ' .
67
Boru
23
^9
Boiio Acid
as
Qaickdlver ore .
71
Carbonio Aoiil .
'd
Salt ... .
75
C!l»y. . . .
BUver ore . . .
77
Cot*It ore. .
XJ
Slate. .
i?
Copper ore
38
Snlphnr . . .
3r
TiDore . . .
»3
Klint.
39
ZlDOora .
85
Fraettone .
41
FanlU ....
87
Chapto
(II.-
— PRoapEcrma.
93
ShoadiiiK . . .
iU
95
HubMhk .
GeoloKT u a Gnide to Minerali
97
PiercinK
Lode Lights .
Altered Vegetation
106
97
107
97
ii
Form of the ground .
98
99
Names otl^uies . .
Gomii. .
99
DiviniDg Rod
Indicative Flanta.
103
Dipping Needle . .
in
Animals u Indioton .
los
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Chaptzr III. — BoBina.
U«ea of Bore-holes . . i
Hethodi of Boring Holes , . i
I. Botlng by BoEJitioa . . i
Angei . . . 1
DiMmoDd DtUIh . . i
II, BorlDK by FerouMlon
withKodB . . I
Iron Bods . , . I
Wooden Soda . . i
III. Boring b7 Peronulon
wtthBope . . I
Amerfcan Sjitaa . I
HUher sad Piatt's
System . . i
Ghapteb IV. — Besasiho Obodhd.
Band toola
Shorel ....
Kck . '. '.
Wedge ....
SawH ....
Toola for Borii^ and Blast-
ing I
HaobineryforBre&kingQronad i
TiuumisBlou of Power
By All .
Water
Electrioity
Bxeatatii^ Huhinery
I. Steam Digeera
II. DMdges
111. Book Drills .
I. Botary Drill*
z. PercnasiTe Drills .
IV. Machines for Onttliif;
I. Meohanioal I^oks .
3. Travelling Bock
Drilla .
3. Ciroalar Saws
4. Bndless Chains
with CuUeiB
5. Wire Saw .
6. KavolTing Bar with
Cutters
V. Haobines for tonnelling
Modes of using Holes for
Breaking Ground .
Driving and Sinking
Fke-settlng ....
Exoavating by Water
SI
ChAPTKB v. — SUPPORTINO EXCAVATIONS.
■ as?
Einda of Timber naed . . 327
Freserration of Timbor . 339
Levels 232
Shafts 336
Working-places . 344
MuoDiy 349
Levels 350
Shafts 253
Working Flaoea . . . 254
Metallic Sapports .
Lersla ....
Shafts ....
Working Places .
Watertight Linings for Shafts 3
Special Prooeeses
Boring Method
Compressed Air Method
Freeong Method .
Haase nocess
Ghapteb VI. — Exploitation.
Open Works . . .3.
Hydraulic Mining. . 31
Excavation of Minenla onder
Water .3
Extraction of Minerals by Wella
and Bore-hole* . . ,3
I Unde^Tound Workings .
Beds
A. Pillar Workings
B. Longwall Workings .
Veins ....
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Ohaptsb YII. — Haulaoe ok Trasbpobt.
tJndergraand ,
B7 Sboota
Kn- ■
SM^ '.
Tehlclea ,
Whaelbanow
Carta and Waggons
BiOlwajB
Powar Used
Human Labour
Anini^ Labour
HachinuT. . . 363
a, Looomotivea . 363
b. Btatioiuuy En'
gines
Oonvejance by Boats
Above Oioond
Sboota .
Pipe* .
Peisous.
Sledgea.
Vebiolet
Boata .
Aerial Bopewajs
ChaPISR Till. — H0I8TIMO OR WlKDIKO.
Hotora, Drams and Pulley
Fiamos .... 387
Bopee, ChaiDH, and Attacb-
Beceptaoles
(a) Backets
(6) Guided Backets
«:) Caf[« . .
Other Appliances
Bignala .
Safety Appliances
Over winding.
StoppiDK Gw
Safety Catohes
Bprinn .
Testily Ropes
Pneaouitio Hoisting
Chapter IX. — Dradtaoe.
Snrlace Watar .... 429
Dams 430
DnJuage Tnunels .433
Sipbons 437
Winding Hacbinery. . 437
Fomping Engines abOTBgroand 441
Motors .... 442
Acoesaortes , . 4^7
FamplDg Eogines below groQQd 466
Worked by Sbeam . 466
Water . 469
Oompreased
Air
■ 470
■ 4^>
Chapter X. — Ventilatios.
Atmosphore of Hinea
Caasea of Pollntion of Air i
Natnnl VenialaUon ,
Aitifidal Ventilation
I. Fnmace Ventilation
IL Mechanical Ventilation
Water Blaat
Steam Jet .
Air Pomps (Fans)
Testing tbe QnaUty of Air
Fire Damp.
Carbonic Acid .
Oxygen
Heasaring tbe Quantity and
Pressnre of the Air .
Anemometers
Wat«r Gaoge .
Efficiency of Ventilating AppU-
Beolstance caused by Friction
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Chapter X.I. — Liohtinq,
Refleoted Daylight .
Candles '.
Torohea .
Ghapteb XII. — Descent asv Ascent.
Stepa and Slides
Stepa
Laddt
. 526 I Buckets and Cages .
Chapter XIII. — DRESsma.
I. Meobauical Proceises
Agglomeiatran or Con-
solidatioD . .565
ScreeniDE . 566
II. Proceasea (Spending opon
Phjsical Frop«nrtiee . 568
Hotloo in Water . . 568
Simple Fall In Water . 570
Upward Current Sepa-
rators . . 574
Separation by Water
Flowing down
Places . . S79
Plane Tables . 579
Percnsdon Tables 584
Travelliug Belt* . 5S5
Buddies . 5S7
Uotion In Air . .589
Desiccation .... 593
Liqaefaction and Distillation . 597
Magnetic Attraction . . 600
111. Piooesses depending upon
Chemical Propertiai . 607
SolutioD, Evaporation,
and Crystallisation . 607
Atmaspheric Weather-
ing .... 6)o
Calcination or Boasting 6tl
Cementation . ' '
Appdlcation of Processes
Loss in Dressing
Sampling
. 616
. 630
. 630
■ P'
■ 633
■ 634
Cbaptbb XIY. — Fbincifles op Euplotkent of Mimnq
Labour.
Chapter XY. — Legisi.ation AFFECxisa Mimes and Quarries.
Ownership .... 653
Taxation 6ss
Working Begnlations . 655
UetalLiferoas Uines Begula-
tion Aots .... 656
Coal Mines Begnlation Act . 662
Other Statutes affecting Mines 663
Alkali Aoia . .665
Boiler Explosions Acts . . 666
Brine Pumping Act . . 666
Elemantary Edacatiou Acts . 666
Employers' Liability Act . 666
ExpioaiTe* Act ■ . . 666
Factorf and Workshop Aots 667
Quarry Fcndng Act . . 667
Elvers Pollution PreTentlou
Act ..... 667
Stannaries Act . .668
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CHAPTBB XTI. — COMDITIOH OF THE MlHXB.
Clothing 669
Hat 671
Boot* 673
Jacket 673
Eonsi):^ 673
Bairaoki . - 674 I
. .677
Sickness .
. 683
Thrift
. .695
B«creation
. . 696
Chapter XVII, — AociDBtiTS.
Death Bate of If iners Irom Ac-
ItdatiTeAocIdei)tHoTt<ait7Uii-
denTonnd aud-AboveKroaiid 699
Claaslflcatlon of Acddeuta . 703
UDdereronnd . jo^
Kniueloiia of Flie Duop
01 Coal Daet . . 704
f kUb of Oioiuid
Shaft Aooidenta
HisceUaneons .
On the SmtBOe
B7 Machinery
Boiler Brplosioni
'MisceUaneons
Ambulance Training
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EEBATA ET OOHRIGEKDA.
P»ge36,Uneio
from bottoin,/of
■"K«m»ge"
rtad "Keamrge."
„ 36, . 18
»
"33,359,000"
., "33.3SO.ooo."
.• i^. » 17
„
'■ HeaUj "
„ "Be»L"
„ i8a, „ 10
„
" Gitbeo -■
„ "Gitbwu."
.. ao9, „ ir
„
-Nobel"
„ "Noble."
,. 3". .. 4 1
rrom
Mp
"deUchod"
., " deUched."
.. 607, ,, >6
.. ..
< ^rSi o^ug b> an error in tbe original, the scale ie incoireot, and t
readings should be mnltipllod bj ij.
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LIST OF ILLtJSTBATIONS.
Frontlapiece: Oreitiand Stoping, Cam Brea Tin Ml"o, ComwalL
O00URR8NCB.
. BtratiBed deposfU, section
. IfBmd lode in slAte, Wheal Waij Ann, Uechenlot, Cornwall
. tin lodiB in graaita, West Wheal Banat, Cornwall
. Section of Iwle, Cuton mine, Otago, New Zealand
;- Diagnuu to abow latdtrlU
i. M aamremenC of underlls
r. Goisral section of a lode
t. Loi^tDdiDal Reotion of a lode ibowing ore-bodiet
II Intaraection of felns
I. Seotion of Tetn with fttdert
iz
E. Change of Btr&e affeoUDg riotiB
|. Rfohnou oi poTBTt; of parallel parts of lodes 1 " Ore gainst ore " 17
\. Hnmatite deposit, tJlvorstoo 19
;. Calamine deposit, Altenbei^, Horeanet 19
i. Stockwork, Mnlberry mine, near Bodmin, Cornwall ... 19
r. Borax Lake, California, plan 24
t. Cobalt ore, Bknttemd, KorwiQ' xj
^ „ „ New Caledonia 28
X Section acnisB Mansfeld distTlct a8
[. K of Ednard II. Shaft, Uansfeld 30
E. Qeolc^cal map of Rio Tinto, Hneln, Spain • ■ 31
![CnM-sectioiisof 8oaUiLode,IUo'nnto 3a
j|CiOB«-teotionaotSan Dionlilo Lod^ Ko Tlnto .
k Hw^ot Lake Snperior copper dUtriot .
L De Been mina, Elmberlej, T^tical section
„ Sallsbniy mine, Johannesbiug
Sheba mine, Buberton ....
aariferooB idluTiam, Cantal District, Veneinela.
showing auriferous " nUDwaab," Cacatal
Baddle-ieefs, Bendigo .
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xiT LIST OF ILLUSTRATIONS.
39. Hoimt Morgan mina, QoMoslMid, Bsotion to Ulojtrate ge^Mi
tbeoi7 48
4a „ n ■• ^*"' °^ deposit 49
41. „ „ seotloiu bMed on late daralopinentH ... 50
42. Grpsam mine, Nottinghamshire 51
43. SoMiouB of ironstone bed, Cleveland 52
44. Chapln Iron mine, Lake Superior, section 54
45. LeBd-beariEg sandstone, Meoberoich, eeneral section . . 55
46. Brenlng Star mice, Leadville, Colonido, section .... 56
47. Manganese ore bed, near Baimontb, North Wales ... 58
48. Natural gas ; section throngh Fiudlay, Ohio .... €0
49. Nickel deposit, New Caledonia 60
|°| „ bearing veins, New Caledonia 6t
1^1 „ deposit, Sudbury, Canada 61, 6z
54. Nitrate of soda, CblU 6z
■'. Otokerite St Borjslaw, Qalioia, plan . ■ ^3
1^'
g
filUng flssaies, Uorjslaw 64
5^ Baku oil radOD, section 6;
59. Sponting oU well. Bakn 66
6ak Deposit of phoepbate ot Unle, Beanval, France .... 68
61. Bed of pbospbatic nodules, South Carotina 68
63. Potassium ults and rock (alt, Staasfurt 70
63. Qaicksilver-bearing sandstone, section, Ekaterincslav, Soathem
Russia JZ
64. Cross section of quicksilver depositiOraatWetteni mine, California 73
65. Longitudinal section n n n ■ 74
66. Cross section of Eureka mine, Nevada 77
■late Ixds, Festlnlc^, N. Walea .... 80
the Oakeley Qaarries, Festlniog . . . . 8t
69. Sijpbiir bank, Iceland 8z
7a „ seam, near Caltaglrone, SIcil; 8a
^ I Craas seotiolis of tin veins, St. Agnes , Coniwall .... 84
73. Hap of part of V^etable Creek, New South Wales ... 85
74. CroM awtion showing " deep-leads " of tin ore. Vegetable Creek 86
75. Waah-ont fault 87
76. 0rdiiiai7 faolt 88
77. Stepfitnlt 88
78. Faolt with lone of broken rock SS
79. Measurement of throw of a faalt 89
so. Section of faolt indicating amount of throw .... 89
I' [ Variation of throw along the strike of a fault .... 90
S3. Berersed fault showing bending of strata 90
84- ,. 90
8«. Han showing heavt ot vein sidemifs 91
86. Olostration of htave aideways produced by a sliding along dip ot
87. Schmidt and ZimmermaDn's rale 92
88. Saoceaaion of taulta, Peohalla mine 93
PBOSPBCTINa.
89. Svotion of mineral vein showing projecting ootcrop ot a hard
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LIST OF ILLUSTRATIONS.
9CX Ciaw-Bectfon of lode with gonao
91. LoDgitadinal MCtion ■bowing; relation of the Koiian to natanl
disinagc level
93. Use of the divining rod
93. Dipping Deadle oMd la Marching for iron ore ... .
94. Earth aogeor or gonge 114
95. Derrick for liftlDg rods II4
96. ,. Ju., for ^riag by rotation . . - I '5
97. Screwed coDpling for hollow boring rode 116
98. Rotating and KDidingamngements and looMoooneoiiou . 117
99. Boring bit with two Mits of catten I17
100. Gnttine out a core with diamond drill 118
101. FlBQ of la^e crown for dianioad drill itS
102. Arrangement of com tabs and sadiment tabs .... 119
103. Oore-eitractor I19
104. Danntleu diamond drill 130
105. Little Cbampioa diamond drill 133
lODk Small diamond drill for prospecting 133
107. Cbiael bit 125
loS. Screw-ioint for boring-ioda 115
109. ., „ „ with oonneotiag aooket . 125
I ICL Lifting hook or dog 135
■ II. Ketaining kej 135
112. Cap, or lifting dog and Booket 135
113. Portable plant for boring with rods J36
114. S«t of toola for lue with above 137
115. Sheil-pomp or ilndger iz8
116I
OeyDbanten'R sliding joint 139
Free-bdllng tool 139
i30l Airaalt'e free-falling tool need with bamping piece . 130
131. Enlarged view of oatcb for tTee-tallliig tool .... 130
133. Kind's free-falling tool 130
133. CiDw's-foot 131
134. BeU^orew 131
laj. Riveted Uoiog tobe with screwed joints 131
136. Lining tnbe with flash sorewed jcAnt 131
t^l '^^^^K '^'^' '°' ontting ont a ooro 133
129. Core extractor 133
1^^ I CompasB-caM for marking oore 133
131. Wooden boring rod used in OaUoia 134
132. Rig for boring by the Canadian syetem 135
133. Amerioan rig for boring a well 138
134. Rope-ao(Aet 139
135. Slnkar-bar 139
136. Jars 139
137. Aager-stem 139
!g|>" ■»
140. Temper screw 140
141. Band-pamp 140
143. Ifethod of worki&g maul for drive-pipe 140
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ivi LIST OF ILLUSTRATIONS.
143. Boring plant, Mfttber and Platt'a sTitem 143
144. Biila^«d view of Mather and Fiatt'B cylindor and palley . 144
145. Mather and Plate, boring lie«d Had tamiDg device .146
146. Racordlng phial for Mat^eorga'a olinogra^^ . - >47
'^ I Snne; ot bor«-hole, Sootehman'i United mine, Tlotoria 149
BRSAEING ORODND.
149. FoU-[^k 152
■5a Donble-pointod pick 152
151. Pick Dsed for cutUhgjad, Bath itone qnairies .... 152
152- >■ witli movable blade, Mansfeld 153
153. Acme piok 153
154. Unlvenal [dak 153
155. Conlah gad 154
i<6. Saw foi cutting freeatone 154
157. Elliott driU 15s
158. Ratchet driU 155
I j!9. Jumper used at Mechemlch 15ft
160. „ „ In NoTthamptonahire 156
161. „ ,. in Festinio^ alate mloea 156
162. >. „ in Cleveland iron mines 156
163. Borer or drill 156
'^IcntUng edge ol drill, Hineia, Nortb Wales . . . ij8
166. Bore-bole with triangular section 159
167. Hammer for afngle-hiuided boring, Featiniog . . • 159
168. Comiab maiUt, or double-handed boring hammer . . . 160
169. Tamping bar 160
170. Nee^, or pricker 161
171. Cbareing Bpoon and sonper t6i
172. Clayfcgbar i6r
'^^ [ Knox BTBtem of boring rending holes 162
175, Beamer, or broach for enlarging boles bj tbe Enox Bjratem . 163
176. Hanarte air-compressor 165
Daboia and Fnncoia airoompnsBor 166
It^rereoll-Sergeant air-oompresaot 167
179. Valve of Ingersoll-Sergeant air-compressor .... 168
180. AnangemeDt of steam and air C7llnders 168
181. Undergronnd reservoir for commessed air, Manifeld . 169
182. Joint for oompreased air main, Blwu; 170
'1^1 Mode of fixing air main In shaft . .170
185. Eadle and Sons' joint for lap-welded pipe 170
186. Dnnbar and Ratton's steam navvy 174
187. Kincaid and McQneen's bnoket dredge 176
188. Priestman's grab dredfer 177
189. Bteavenson's tfrlst drill on carti^e, worked by electric motor . 179
19a. „ „ „ „ petrolenm engine iSo
191]
m r^** ™^ *^ machine drills . t8i
"94) ■
19$. Bh^ied hats of steel for cross-Uta 1S2
J96. Barrow drill 1S3
197. Drill moanted on stretcher bar 1S4
;;l-:
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LIST OF ILLUSTRAIIONS. irii
198. CUmu driU 185
^Z^BDaaeyeiue, or boring ram of Dubois uid Francois . 1S6
aoi. Iiig«noU-Sergeuit SclipM drill 1S8
^ I Socket for holding the tool . ^ 1S9
004. PMoke drill 190
305. Use of Fiauke drill and ondercntcli^ chisel, Uauafeld copper
minei 191
ao6. Himmnt drill 191
307. 8«rgeMit driU 193
308. „ tnining mecbanlsm 194
309. Addaide drill 195
3IOL Dkrllngton drill, longitudinal Motion I96
31 1. „ „ side eleratlon 196
313. „ „ mooDted on stretcher-bur .... 197
313. Harrin electric drill, working parti 19$
314. Franke's mechanical chisel 300
315. OiUott and Copley's andercattlngmaohlDe Z03
3li. Walker's ciroiUai saw 104
317. Wiie saw 305
318. Stioilej'B tannelllDg; machine, aide elevation .... 307
319. Slliott multiple wedge, lot^tndinal and cross BBCtlons . . 305
_,, l-Strength of explosives as shown by Tianil's lead block U
I. Detonator, Nobel's, treble strength 318
qnintnple strength
238. Firing a ohai^ h<
339. Rifting hole with air-sriace shore charge, Knox system
330. Binmltoneoas fuse of Euckford, Smith & Co 319
331. BimIu'b hlgh-tanaiou electric fnse 330
332. Mobel's „ 331
333. „ low-tenaion „ „ 331
334. Flanning boles for driving a level by band izz
335. Sectioa of lode with govge or ttlvage 323
336. Amngement of holes for driving a level with a machine drill
(elavation) 323
337. ArrangemeDt of holes for driving a level with a machine drill
(longitndinal section) 323
338. Halkyn drainage tunnel, arransement of holes for driving . 233
139. Driving level with Ferronx drill and bossejeose, Bex, Switxeriand 334
240. Anangement of holes for sinking a shaft, Fcxdale, plan . , 335
341, „ „ „ „ „ section . 325
SUPFOBTINa BXCATATIONS.
243. Larel with cap or bar supporting root 332
343. „ „„ and leg 232
*^ ( Ji^ts between cap and leg 333
34& Timber frsme and lagging for level 332
247. Horned set for level m loose gtonnd 333
348. Timber fiame andlagglng for heavy groaud, Comstook lode 333
349. Tlmb«dng for level. Ho Knto mines 233
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x\
xviii LIST OF ILLUSTRATIONS.
25a. Pigsty timbering for wide level, OHWt-sectioa 334
351- „ „ „ „ seation along line of itrike . 33;
351. Spiliing in loose ground, longitodinal section .... 336
353. „ „ „ cross section 236
254. Plank lining for shaft, plan 337
2K. Shaft frame or set 337
350. „ „ enlarged view of joint 337.
357. Plan of timbering for shaft, Comstock lode .... 2}li
">. Section through dividing „ „ . . . . ajS
>. End view of t:mbering for shaft „ „ .... 238
I. Flan of timbering for shaft, Calutnel anil Hecia mine 239
261. Shaft timbering, Clanathal, plan 340
263. ,, „ „ end view 341
363. Timbering chamber for waCer-whee), ClaDSlhal .... 341
364. Plan of shaft frame for spilling 343
365. Sinking shaft b^ spilling, vertical section 343
366. Prop supporting roof of 1>ed 244
267. Chocks supporting roof 245
268. Large chocks, Wielicika salt mines 345
369. Figst; timbering in stopes. Day Dawn mine, Queensland . . 345
370. tjqoare set, Comstock lode, Nevada, elevation .... 246
371. ,. „ „ „ plan 246
372. „ „ ,. „ applioation in overhand stopes 246
373. „ Richmond mine, Nevada 247
374. „ timbering in overhand stopes, Broken Hill mines,
sectional elevation 348
375. „ timbering in overhand stopes. Broken Hill mines,
horizontal seoCion 248
276. Joint for square set. Broken Hill mines . 249
377. Square sets supporting banging wail 249
278. Strengthening square seta 249
379. Dry TOlling for level, Forest of Deon 250
38a. Le\e1 linedwich masoory, Claostlial 250
351. Level with arch of masonry 251
283. „ „ „ at side 351
383. Lining shaft with brickwork 352
384. Shaft lined with concrete, Fozdale niine 353
385. Stone pillar sepporting roof 254
286. Halkyn drainage tunnel, section showing Iron sapporls . 355
2S7. „ „ „ casUiron prop and chair . 255
388. „ „ „ section of iron rail nseJ . . 256
289. Section of steel beain, Nunneiy Colliery, SheHield . 256
290. Steel beam on timber legs 257
391. Boiled steel cape and l^s forming frame for level . . . 25S
||H Section and plan of steel plate used 258
394. Level lined with carved iron rails, Harts 358
395. Bent steel bar for supporting roof of level 259
296. Steel frame in two parts for lining level, Aniin .... 259
297. Cross section showing joint 360
39S. Steel frame in three pieces, AdsIh 260
299. Oircalar frame for level, channel steel 261
30a. Section through joint of the frame 361
30:. Ciroular frame for level, bulb-tee steel 362
303. Section through joint of the frame 362
J03. Iron ring in two parts for supporting shaft lining . 363
304. Shaft, lining, ozokerite mines, Boryshiw 364
305. King of channel Iron for shaft 264
306. SecUon through joint of ring 365
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LIST OF ILLUSTRATIONS. lir
ysj. Flop of X-steel, and {dan of end 366
308. SolU wooden tobbing for abaft, plan 266
309. Section* of OMt-iron wedging onbs 367
31a Bectlou Uuongh ooSeriog 268
311. Segment of cut-lroB tnbbli^ 169
^'^ I CBst-iion tnbbing resUiig on cnib 370
314. Small compodte borer or trypan, Kind-Chaadron sjMtwa . . 273
315. I^rge composite borer „ „ ,< . . 373
316. Section of tubbing with moas-box „ ,, „ . . 274
317. „ -. II I. compressed, and falsa tabbing 274
31& BnlJuged section of (be three wedging onrbs .... 374
319. SecCiAn of tubbing st Lievin 376
330. Sinking hj freezing process In wB.ter7 strata, Siberia . 379
331- .. r. .. .... 380
3>3. Poetscb's freexing process, section of freediw tube . 283
323. „ „ „ vertical section of shaft . 382
EXPLOITATION.
' 324. Open workings for iron ore. Northamptonshire .... 187
335. „ „ plan dwwingurangement of workings 388
336. SecUon of terracer, Penrhjn slats qnsrrj 3SS
317. View of omocest, Bio Tinto mines 3S9
338. Section of MalbBir? mine near Bodmin, Cornwall . 389
339. Section sliowing cflsct of a large blast, Messina . . 390
^L Details of the tnnnel for lai^e blast „ . .391
333. China clay workings, Henefaarrow, Cornwall .... 393
333. End view of flame and trestle 394
334. View of flume canisd scroas a. valley 394
33;. „ ,, „ by it-on brackets on aide of eahon . . 395
336. Riveted wronght-iron water pipe 295
337)
33StFresstirebox or "bnlkhesd" 396
3*^ iHydranllo elevator 300
3J0. Working salt by bore-bole, Middleebroagi
351. Plan of Dore-boles, lliddlesbrough
3S3. Section of niide^;roQnd gypsnm qoarrjes, Paris .
353. Plan „ „ „ „ .
354. Undei^roBncI workings for stone, near Bath, plan
355. „ „ „ „ vertical section
35^ •> 'I •• " Pl*"
357. Flan shiowing pillars, Marston Hall salt mine, Korthwioh .
358. Vertical section „ ,, n >■ ■
359. Uudergroond workings lor slate, Festiniog, plan
360L „ H » 11 ccoss-seotion .
361. „ „ „ French Ardennes, croBB4eotion
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XX LIST OF ILLUSTRATIONS.
3^. Workfng IroDatone, ClereUnd, plan 316
363. BagtinDgnet tin sCrsam works, plan 317
364. „ ,. „ leotioii 317
365. Croes-aecUoti of the Red Point &nd Damm chaEmels, California . 319
366. Plan of longwall worUngfs, M ansfeld copper mine . . 314
3G7. TransTerse section of Ml ore mine, lode worked bj vertical ahslt 316
368. Longttndinal , 3^
^ [ Underhand stoping. origloal method 317
371. „ „ on Bides of winze 317
373. LoDgitadinal section of Dolcoath mine, Cornwall . . . 33S
373. TnnsTerse aeotion „ „ ., ... 3^9
374. Overhand atoplog, with mbbiah stowed on Btnlla . . 329
375. „ „ oroBS-section 330
376. „ „ excavation left open 33O
377. „ „ on a narrow lode, croBs-seotlon . . . 330
37S. Working a wide lode with fllling np, Van mine . • 33'
379. Wide lode worked by cross-cnttiDg, tmnsTeTBe section 334
3*>- « .... plan 334
381. „ worked in elices, parallel to the dip .... 335
382. „ worked in horizontal slioes, with filling np, Fozdale
Mine 336-
^tworklnga wide lode having a bard and a Boft part . - 337
385. Rio Tinto, inllar and chamber workings, vertical seotion . . 339
380. „ „ „ „ plan of preliminai;
diJTBges . . 339
387. „ „ „ „ plan ot completed
chambers . 339
388. Working " chamB," Forest of Deao 340
3S9. Plan of De Beers Mine, new system ot working .... 341
390. „ of drlvages and chambers 34Z
391. Vertical secti on of drjvages and chambers 342
393. Hnmatlte deposit, North LancaBhire, croBS-section . . 343
393. „ „ plan of main levels and oroBscuts . . 343
394- i< •< plM of workings 344
395. „ „ section of working 345
396. Working linc oro, Diepenlinchen mine 34&
HAULAGB.
^^ I Sections of rails 351
399. Steel sleeper, Legrand's 352
400. „ „ Howard's 352
401. „ „ made from bridge rail 353
4010)
403 } Clip nied with above 353
402a)
403. Sleeper made of cliannel-iron 353
404. „ „ flat l>ar.iron 353
405. Cast-iron tnrnplate 354
406. Tnrnplate with iron bar gnides 3J4
407. Mine wa^on, Van mine 355
j^ t Mine iraggon, with sheet-iron bod; and bent sides . . . 356
410 1 „ „ ,. oval body and antomatio Inbrioatlon,
411/ Salnt-Btienne , , 350
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LIST OF ILLUSTRATIONS.
^j[ Steal waggon, Uanbradach collieij
414- SaU-oillug- p«deatml 361
41 j. DiBgnm, main and tail rope iTstem 366
*J*|BiC8'. dutch 369
418)
4i9i-Eiidlaniope i^Bteiii, plaiu of sldiugi 370
430}
431. „ „ „ double traak 371
422. Drama and afr-brak« <tl telf-ncting inoline, Bilbao . 377
423. AEtial ropeway, Otto's B;st«ia, visw of tnb 382
Si raWmUri .... 383
41& ., „ „ „ clip, side view .... 384
427. „ n II 11 CTOBS-SeCtiOD of Ollp . . . 384
438. •> H ,1 II pl^ii of olip .... 384
429. ,, „ „ „ Sheba Qold Mining Compaoy,
BarbertoD 384
4ja „ „ Oott«ssegeii Colliery, Upper SilMla . . . 385
HOISTING.
431. Turbine and connectiona for windiiig, Great Wast Van miae , 390
At« [ Compotind winding ei^lue, Llanbradaoh Collierr . 391
434. Dmm with reserve length of rope 392
435- n " ,. « section 392
436. Reel for flat rope, elenition 394
437 plu 394
438. Wooden pnUey-frame, side deration 395
439. ,. .. 'ront , 395
440. » .1 plan 395
441. Wrooght-iron bead-gear, "Book Shaft, "De Beers mino . 396
443. Winding polley 39S
443a. Win rope with hemp core 399
^l „ „ ordinary, new and when worn 400
J^f „ „ Lang's lay , „ 400
^^ f ti n Latch and Batchelor'a " flattened strand " . . 400
450^ H n •• " 't OQtafde view . 400
451. .. „ Bitot's " locked coil " 401
452. Spring hook for attaching rope to bnoket, Ac. ... . d02
453. Cappug wire ropee, eye spliced on 402
454. „ „ „ eye made with screwed clamps . . 402
455- I. I, 1. It .t -. 1 .. Motion . 403
456. „ „ „ socket riveted on 402
4j8t 11 n II for looked Qoll rope, ontside view and saotions 403
459)
^ [ i> n II improved fonn of damped capping . . 403
462. Wronght-iron kibble ., ,. „ „ . . 404
463. Aerial incline, " Bloudin," ased at granite qaarrien, near Aber-
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uii LIST OF ILLUSTEATIONS.
464. Galloway's Improved wire rope nidBs for bucket • 408
465- „ waUicg stage, elerfttion 409
466. „ „ ,. plan of lower floor .... 409
46J. Filliae Bkip in abaft 4"
468. Self-fiscbai^g skip, D© Beers mine, plan .... 413
469. „ ,, „ „ „ Bids eleTatioQ . . 413
470. ImproTed shoot with double doois, De Beers mine . 413
47>. Antonuttf o daiD[tog ammgeinent f or iuclinea, aide elevation . 413
472. „ „ „ „ plan . .413
473. „ „ „ petpeudicolu "Rock" shaft,
De Bbon miuey aide eleva-
tion 414
4?4- II i> " n II front eleva-
tion of apart . . 415
47c. Ormerod's detacbiag link .- 416
4761
477
47S [ Self-dlBChajgiDg skip, Frongoch mine 417
479
4S0I
4S1. Cage, Comstock lode, front elevation 418
483. „ „ „ side elevation 418
483)
4S4 [ Haniel k Laeg's kepi for cage 420
4|S)
^ I Detaching; books, King k Bumble's 42^
^} -I - Walker's 4*3
49°- <i >i It opea 414
DRAINAGE.
491. Wooden dam in level, plan 430
'1^ t Spherical wooden dam 431
4941 .„
496. Briok dam in shaft, vertical section 433
^^ I OftUoway'a pneamatic water tank, vertical section . 43S
499. „ aatomatic water tank, side view .... 439
500. n ,1 II front view .... 440
^ I Bowden's automatic tanks for nse on ilopea .... 441
503. II n I, damplDg at bead of slope . 441
504. Compound donble-aoting pumping engine, Uanateld . . . 444
503. Strapping-plates for wooden pnmp rod 445
506. V-bob, side elevation 446
507- " Pl" 446
505. Fend-off bob, side elevation 446
509. Rnnnliig loop, side view 447
510. I, „ front view 447
511. West k Darlington's hydraulic plnagers for working iucllued
rods 447
512. Dtawing lift in shaft, vertical section 449
^1^ [ Fnmp bucket for single valre 449
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LIST OF ILLUSTRATIONS. ixiii
5'S- Half-moon 449
516. Form for two Talvea attached at drcoiofereiice .... 449
517. „ „ „ in the middle .... 449
51S. Bhapeof leatbeTbaodforpacklnKPDmpbncket . . 449
519. Lifting pomp nsed cm the Comatock lode 451
530 1 Hinngmatn, joint and mode of anpporting column in abatt. Com.
5ZI) stock lode 451
523. Planar pnmp in shaft, rertical sectian 451
*^ [ Hake's month Ttdve 453
1^'- Batteifl; yalve 4S3
. [ Trelease's valve 453
s»8r
5*9)
531)
Teagnt'a noiseless valve, vertical section, side view and plan . 454
Double-beat valve fixed in place, vertical section , . . 454
„ open 454
.. ,, „ elevation of valve and lower seat . . 454
Sltlinger pnmp, elevation 456
„ ,, vertical section 456
Balance bob 457
West and Darlington's hydranlic connterbslaiice . 458
„ „ . „ „ for inclined rods 458
Bocbkoiti r^eneiator 459
Bossigneox's system of connteibalancing 460
„ „ ,, plan .... 460
Catches 461
Pamping engine, Shakemantle Mine, side view .... 463
„ „ „ „ front view -4^3
Pnmps fixed in shaft „ „ side view .... 464
„ n ,1 „ front view , . 464
Pomps in shaft, bottom lift, Shalceroantle Mine, side view . 465
Plan of shaft „ „ . . . . 465
Pnmps in shaft, bottom lift „ ,, front view 465
UndergTonnd pnmping ei^ne, Mansfield 468
„ „ „ „ plan .... 468
Polaometer, vertical section 469
Moore's hjdraalio pomp 470
PohM pomp 471
Pnmp worked bj compressed air, Bvans and Veftch . . 472
„ „ „ „ oylioders for working volvea . 473
VBNTILATION.
L Natoral ventllatioD by two shafts joined by a level
1^ adit and st^ft .
by two shafts joined by an incline
of end of level
of a single vertical shaft
of an Incline
of end of level by an air-eollar
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iiiv LIST OF ILLUSTRATIONS.
569. Nktunl ventilAtiou of etutft br mi »ir pipe 4S8
57(X Method of TenttlBtlng u rise 488
571. „ „ lower level! 489
573. „ „ b7 wintoi 489
573' Ventilating furnace, verUcal seetion 491
574- .. .. plan 491
575. „ „ froQi elefation 491
576. WiUiaiiu' water- jet appaimtaa 492
577. Teepie'i aiplrator 493
578. Barts blower, elevation 494
579 Bootion 494
58a Roots' blower, cross section 494
581. Capell fan, vertical sectfon 495
581. „ „ cross section 49S
583. Gulbal fan, vertioai seaCion 49S
584. Schiele fsn „ „ 497
585. Waddle fan 497
5S6. Lnugie's appaimtos for testing tlie air of mines .... 504
587. „ „ valve-tube, vertioai section .... 504
588. Water-gaage, model to Ulnstrate action of .... 508
JS9. Hurxne's graphic lepreseutation of the inQuence of the sidee
of airwajs apon the amonnt of friction . , . ■ 5 ■ ^
UGHTING.
590^ Caudle bolder, United States 514
591.. „ „ ("Spider"), Anstralia 515
592. Lamp for bnmli^ oil, Scotland 516
593. Wells light 517
594. Davy iMQp 519
595. Claim; lamp 519
596. Ilaeselei lamp 530
597. Harsantlamp jii
598. Ashworth's Hepple white- Ura; lamp jas
599. Sussmami electno lamp 533
DESCENT AND ASCENT.
600. Iron ladder 519
601. Section showing manner of joining two ladders . . . 529
603. Arrangement of ladders in shaft 530
■ Donble-rod man-engine
605. Slogle-rod man-engine
DRBSSINQ.
606. Botarj diamond washing machine 540
607. Bevolving drum for washing smalls before picking . . . 541
608. Scraper 543
609. RagftlDg 543
610. Spalling 544
611. Cobbing C44
613. BnclciDg 545
613. Thin wedge for splitling slate. North Wales .... 545
614. Blalie's rook-breaker, section 547
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LIST OF ILLUSTRATIONS. ixv
tiij. Dodge cmsbei 548
616. lo-stamp batteiy with wooden frame 549
617. SiDglB dUcluuge mortal 549
6i8, TftRiet 549
619. Cun 549
630. Stemp bead, shoe, aod die 549
611. Steel shoe and die before &iid after wear 550
623. Sail's steam-hammei stamp 553
633. Learitt's dlffarential ■team-^jlioder 553
614. Comiab orasbinK rolls J54
SRoUa, cross secuon J54
Krom'a roll, sectioii 555
637. Krom's crushing roUs, side elevatioQ 555
62S. Edee-ratmer 557
639. BaU pnlreiiMT, Empp^rnBonwerk, croM-tection . . 558
63a „ „ „ „ longitudfoat section 558
631. Carr's disintegrator, section 559
632. Oatea crusher 560
^3. Hnntington mill, plan 561
634. „ „ sectional elevation 563
£35. Fazman's improved roller and yoke, wction .... 561
^ „ ,, ,. „ plan 563
637- „ ,. .. .. S63
638. Sawing maohlne for slate 564
639. Qreaves* dioiilar slate-dressing machine 565
64a Perforated sheet-metal, with romid holes, imm. . 567
641. „ „ „ „ „ 2mm. , 567
643. „ ., » » ,. 5i»ni. ... 567
64241. Trommel for making fonr classes 567
643. Sxperimeut to show sepeiatioo of minerals bj free fall in water 569
S*l [■ Towing and packing in keeve 571
646. Experimental ji^ing-sleve 571
647- t. JiggB' S7'
64SL Two-compartment jigger, front sectional elevation -573
649. „ „ „ croM-ieotion 573
65a Bzperimental j^er with fixed sieve 573
651. Jigger with piston moving hoiiiontally, Froi^ch mine, cross-
seotloD 574
653. Ji^er with piston moving horizontally, longitudinal cross-
Mction 574
653. FTiamidal separatOT, Jaoomety and Lenlcque, section 575
654- » .. .. plan . . 575
£55. Upward onrrent separator, Frougoch mine, seotion . 576
656. „ „ „ „ plan - 576
657. Osterspey's siphon separator, vertical seotion .... 578
658. „ „ „ longitndinal section of front
chamber 578
659. „ „ „ plan 578
£60. Cornish self-acting donble frame, plan 580
^1 „ , sectional elevation ... 580
663. Unkenbach table, ssotioual elevation 582
664. „ „ plan 582
665. Bevolvii^ ronnd table, Jaoom^tj and Lenicque .... 584
666. „ „ „ „ ,. plan ... 584
667. Bittinger'i tide-blow peroossion table, plan .... 5S5
668. Frae vauner, diagranunatic lonRitadinal section . . 585
669. Stejn's endless bdt, side elevauon 587
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xxvi LIST OF ILLUSTRATIONS.
670. Btein's endleu belt, plan 587
671. „ „ „ «nd elevation 587
672. Convex ronDd buddle, BectiocuU elevation 5S8
673. „ „ „ plan S8S
674. Experimental pnenmatio jigger 590
675. Cltu-luoii-StKnfleld concentntor 591
676. Tanks and dijtne Sootx tor ohlna olsj, pl»ii and a ciOBt-HCtiou. 593
677. Kiln for dr;inK hUer's earth, section 59;
67S. Raelle's revolving drier, loDgitndinat section .... 596
679. lAi^e kiln, Sicilian inlphor mines, vertical HoUon . 599
680. „ „ „ „ plan 599
681. Chase magnetic separator, longitudinal seotion (diagmnmatic) . 601
68z. Conkling magnetic separator £01
683. Hoffmann magnetic lepantoi 6o3
684- Kessler magnetic asparatot 603
685. Lo»ett>Finnej magnetic separstor 603
686. Ball-Norton magnetic separator 603
687. Bachanan magnetic separator 604
688. Friederichssegeu magnetic separator, longitudinal section . . 605
689. ,. „ ,, plan 605
690. Wenstriim magnetic separator 605
691. Edison's magnetic sepsj^tor 606
692. Brunton's calciner, sectional elevation 614
693. Hookln'g calciner, longitadinal section 615
694. „ „ plan 615
69J. Sampling— quartering 633
696. „ sbovel 633
697. Clarkson's rapid sampler 635
698. Brtdgman's ore-sampler, first apportionei 635
699. „ „ second 635
CONDITION OF WORKMEN.
70a Barracks for workmen, Eisleben, front elevation . 675
701. „ „ „ ground plan .... 67;
702. Cottage, Bolsover Collieries, front elevation .... 678
703. „ „ „ back „ 678
704. „ „ „ first fioor plan .... 678
705. „ „ „ ground plan 678
706. Dry or changing house, Levant Uine, Cornwall, side elevation , 63o
707. „ „ „ „ „ plan . 680
708. Shower-baths, Aniin Collieries, France 681
ACCIDENTS.
709. Lowmoor jacket and Purlej pattern stretcher
71a Placing stretcher on Asbford litter
711. Ashford litter
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LIST OF ABBREVIATIONS.
Ann. J/iW. — Ancialee dee MineB.
Ann. Bep. R. ConiwaJi iU. Sm. — Annnal Report at the Rojal Comwall
Pol;t«chmc Societ;.
B. ».h. Z.— Berg- und hiitteDmamiische Zeitnng.
BvU. Hk. Ind. 3fin.— Bulletin de la Society de I'lDdOBtrie Hininle.
Ci^L Onard.— The Colliery GaardiaD.
Oompta Bendui MennuU, Soc. Ind. Xia. — Comptes rendni menenels de la
8oci^t£ de I'Induatrie Minerale.
Jahrb. f. d. Berg- und SottenKtMen im K. Saehaen. — Jahrbnoh filr das Berg-
nnd HQttenweaen im Konigreiche SachBen.
Jakrb. f. Gecl. Mm. PoZapxC.— Jahibuoh fUr Geologic^ Mlnetalogie und
nUiloDtoIogie.
Jour. Sot/. Intt OonueaB, — Jouraal of the Royal Institution of Cornwall.
Jinir, iSoc Arlt. — Joamal of tbe Society of Arts.
/our. Soc CSiem. Ind. — Jonnial of the Society of Chemical Tndnatry.
J/em. Gtri. Survey, — Memoirs of tha Geological Survey of Qreot Britain.
Min. Jour. — Mining Journal.
JUin. Slat.—UiBeal 8tati«tiCB of the United Kingdom.
ilTcuM Jahrb. f. Miner. QeoL u. P<ddoatologie, — Neues JahTbnch tSl
Mineralise, Qeologie und PalAontologie.
Oett. &iUttr.f. B..U.S.- »■«««.— Oesterreiohiaohe Zeitsohrift fiirBe^
und Hattenwesen.
PkU. TVani.—FhiloBopbioal Transactions.
Proc Arf. Iwt. M. j:.— Proceedings of the Federated lostltate of lllnlng
Engineers.
Froe. Ingt. GinU Eng. or JVoe. I«$t. C. E. — Proceeding* of tbe Institution
of CiTil Engineers.
Proc Intt, Meek. Bng. or Proe. Intt. M. E, — Prooeedings of the Institution
of Hecbanical Engineers.
Btoe, Min. Imt. Cbmmatf.— ^Proceedings of the Mining Institute of Com-
wbIL
iVoc SotOh Waiulnit. £nfr.— Proceedings of the South Wales Institute of
Engineers.
Quart. Jour. QeoL 8oe. — Quarterly Joamal of the Ueological Society.
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Kviii LIST OF ABBREVIATIONS.
See. GtoU Survtj/, India. — RBCords of the Geologtcal Barrej of India.
Mtp. Minert' Auoc Gomicall. — Report ot the Hiuere' ABaociatiou of Corn-
wall and DevoD.
Sial. Min. France. — Sbitistique de I'ladustria tninfiraJe an Franoe.
TranM. Amer. lint. it. E. — TranBactioiiB of the American Inatitnte of
Mining EngiDeert.
Trant, ln$t. Bog. arid Sh^tbuIUleri in fixtiand. — Transaotiona of the Insti-
, tnte of Engineers and Shipbuilder* in Scotland.
'JVant. lait. Marina Eng. — Tnuitaotions of the Institnte of Marine En-
Trani. Maneh. OecL Soe, — Tnuuactlous of the Hauohester Geological
Bociet;.
Trant. Mitt. Amoc- and Jntt. Cortua^. — Transactions of the Hineri' Asso-
datloD and InetUnte ot Comw&ll.
Trant. X. of Eng. Intt. Mia. Eng. — Transactions of the Nori^ of England
loaCitnte of Uining and Heohimlcal Engineers.
Tram. B. QeoL Soc. ConucaU, — TrangBctions of the Rojal Creological
Society of CornmlL
Tram. Technical Soe. J^ tSxwt.— Transaction* of the Technical Society of
the Fooiflc Coast.
^dtidir. d. d. gtol. Oeitll»ch.-~-Z6itectniIt der deut«chen geologiachen
Geaellscbaft.
Ztitichr. f. II.JT.-'w. S.-TrfM«,— Zeitschritt fUr daa Berg- Batten- und
Ballnenwesen im preassischeu SCaata.
, Google
A TEXT-BOOK
ORE A]!^D STOI!^E-MIISriNG.
INTRODUCTION.
The ftrt of muung, In the broadest sense of the word, consutB of
the prooeeses b; which the useful minerals are obtained from
the earth's crust. This definition is wide, for it includes under
tiie t«rm " mine " both open and underground excavations ; but
it excludes eubterraneon workings which are simply used as
I, such as railway tunnels, sewers, and galleries for military
The word " mine " is derived from a low-Latin verb meaning
to lead, and equivalent to " ducere ; " we have the French word
" mener," from the same source. No doubt originally the mineral
deposit ii^elf was called the ''mine" or " lead," and this siguifi-
caticm has not been entirely lost, for we atiU find the word " mine "
need as a synonym for " seam " in the case of oonl and ironstone.
I must remark that the word " mine," or its equivalent in
other languages, varies in signification in different countries on
aocoimt of 1^1 eoactmeutB or decisiouB which define it. In the
United Kingdom it is the nature of the ezcavatitm, and not the
nature of the mineral, which decides whether the workings are a
miitaornot. For legislative purposes the term "mine"is restricted
to woAings which- are carried on below ground by artificial light ;
bat in oonunon parlance this rule is not observed, and the word
used depends upon the mineral itself. Thus the underground
WM-kings for btulding stone near Bath, and for slate at Festiniog,
are usually spoken of as quarries, but are treated legally as
In Belgium, France, and Italy, on the other band, the work-
ing for mineral are classified according to the mineralogical
nature of the substance wrought. The French law of 1810 makes
three claaaee of workings : mintt, miniirw, and carriiret. Deposits
ot gold, silver, lead, copper, sulphur, ooal, and beds or veins of
iron ore form mijies. Under the head of miniiret, for which we
have no equivalent word in English, are included bog iron ore,
pyritoQS earths fit for working, sidphate of iron, aluminous earths
and peat, whilst the earriirea, or quarries, comprise workings for
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3 ORE AND STONE-MINING.
Btone, clay, s&nd, etc., whether ftbove or below ground. The
statute of iS66 has assimilated the miniirei to the quarries, and
the law now becomes very like that of Italy (1859), which distin-
gaishee simply mines (mtnt«re) and quarries (cace). Deposits con-
taining metallic ores (excepting metal-bearing sand or earth),
eulphur,bitumen,Goal, or lignite are worked as "mines," whilst pits
from which sand and gravel are obtained become legally "quarries.''
The consequence is that what is merely an underground stone
quarry in France would be a mine in England ; whilst open
workings for iron ore, such as those of Northamptonshire, would
be true mines under the French or Italian laws.
In a general text-book upon mining, it is therefore necessary to
go beyond the British definition of a mine and to include the
methods of working minerals in excavations open to the daylight,
as well as in those which are purely subterranean.
The in'P'"g of coal is a subject of so much importance,
especially in this country, that it requires a special treatise;
this has been prepared by my friend, Mr. H. W, Hughes,* and
my task consists in describing the methods of winning and work-
ing all other useful minerals, whether solid, liquid, or gaseous.
Furthermore, as it is customary for the miner to cleanse or pre-
pare his ore or stone for sale, I shall explain the processes which
are usually carried on at the mine, and can be fairly included
under the convenient term " dressing." Finally, a few remarks
will be made concerning l^islation Meeting mines in the United
Kingdom, the condition of workmen, and the ocddents to which
they are exposed.
The subject has been divided into the following chapters: —
(i) Ooomrenoe, or manner in which the useful minerals are
found in the earth's crust.
ii) Frospeotiiig, or search for minerals.
3j Boring.
(41 Exoavation.
(5) Bitpporting ezaavatioiiB.
i6) Exploitatioil, or working away of minerals.
7) Hanlage, or tmnaport along roods.
VS) Winding, or hoisting in shafts.
(9) Drainage, or removal of water.
(10) Ventilation.
(11) Lighting.
(12) Deaoent and ascent.
{13) Dressing.
(14) PrinoipleB of employment.
(15) Legifllatlon.
(16^ Condition of workman.
(17) AooldoQts.
* A Teii-Bo<^ of Cold Mining, London, 1891.
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( 3 )
CHAPTER I.
MODE OF OCCUBRBNCB OF MINERALS.
ClastiflcMion of mineral repositories. — Beds. — Veins. — Haai
sffeotiog tbs productiveDBM of vtlaa. — ThmirieB conceming the
formation of vuins. — Exainplea of mineral deposits arranged alpba-
betictt]];. — Faults or dielocittfoiis.
CLABBrFZCATZOB'. — Tarions conditione may be taken as
the baeea of classification of the rocks which form the crust of the
earth. One striking characteristic is the presence or absence of
beds or layers. A rock made up of parallel beds, or layers, or strata,
is said to be etnUifitd ,- a rock in which no such structure exists
is called ungtrcUifUd. When we examine the stratified rocks
closely, we find that, as a rule, they have been formed at the
bottom of seas, lakeu, or rivers by the gradual deposition of
sediment, by precipitation &om solutions, and by the growth or
accumnlatioD of animal or vegetable organisms. As instances
may be atod beds of sandstone or clay, formed by particles of
nnd or mud settling down in water ; beds of rock salt, resulting
from the gradual diying-up of inland seas ; beds of limestone,
formed out of old coral reefs ; beds of cool, due sometimes to plants
growing upon the spot and sometimes to plants washed into
lakes or estuaries.
The unstratified rocks are frequently crystalline. In the
case of recent volcanoes we see molten rocks issuing forth from
the earth, spreading over it, and consolidating into a crystalline
mass, and we may fairly assume that many of the crystalline
rocks now met with at the surface were at one time in a soft fused
condition. Internal evidence leads to the belief that the process of
consolidation often took place at a veiy great depth, and on this
account geologists have subdivided the crystalline unstratified
rocks into volcanic, which hardened like recent lavas near the
surface, andplutonia, which became solid under the heavy pressure
of thick masses of superincumbent struts.
One class of crystalline rocks has given rise to mach contro-
versy, viz., the rocks in which the crystals of the constituent
minerals are anuiged in roughly parallel layers. The rock has a
flal^ etnictnre, and is known as a crystalline schist. Some
crystalline schists have all the appearance of being altered sedi-
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4 OEE AND STONE-MINING.
meutary atrata ; Id others the foliated structure is con^dered b
be the resutt of pressure upon pre-ezisting ciTstalline rocks.
We therefore may closaif}' the principal rocks as follows :
/ Sedimentary origin.
I. Stratified . J Chemical origin.
I Organic origin.
Volcanic.
Plutonic.
. Unstratified .
The crystalline schists must be placed in one or other of these
two great divisions, according as they are looked upon as an
altered form of stratified or of unstratified rocks.
This classification is not entirely satisfactory. For instance it
separates two of the products of a volcano. Volcanic ai<h falling
into the sea will settle down and form a stratified rock, whilst
the lava issuing from the same vent is unstratified. Again it
does not include sea-water, an important source of salt. How-
ever, for the purpose of the miner a simple classification is
advisable, and it will he found sufficient for his purpose so long
as it is recollected that occasional anomalies must be expected.
Any one of the five classes of rocks just mentioned may be
extracted from the crust of the earth for commercial purposes.
Among the bedded or stratified rocks cool is the most im-
portant, but in addition we have beds which are commercially
valuable on account of the metels they conttiin, such as copper,
gold, iron, lead, manganese, silver, and tin, orpiecious stones such
as diamonds, garnets, rubies and sapphires ; other valuable beds
axe native sulphur, rock-salt, and innumerable kinds of stone for
building, decoration, paving and road-making, clays for making
pottery and cement, oil-shale and alum-shale.
From the unstratified rocks we obtain supplies of stone for a
great variety of purposes.
In addition to mineral deposits, which consist mainly of
original constituent members of stratified or unstratified rocks,
we have a third important class in which the repository of the
valuable mineral has come into existence suhB^iuently to the
consolidation of the rocks which surround it. If the repository
is, roughly speaking, tabular or sheot-like, it is called a mineral
vein or lode, and if in any other form it is a mam.
Hence the series of mineral repositories might be classed
according to their origin as follows :
T, . „ . . ( Stratified.
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MODE OF OCCTIKRENCE OF MINERALS. S
But even here we encounter difficulties, for unstratified rooka
Bometimes occur in the form of veimi ; beBides which primary
origin is not a term which ie strictly applicable to beds formed
from Rediment which consists of fra^^ents of other rocJcB.
It is not unnatural, therefore, that outward form should have
beea chosen as a convenient basis of classification, and accordingly
mineral repositories have been separated into :
Tabular or sheeHike . j *' ^^
Non-tabular , . 3. Masses.
TABTJIiAB DEP08ZTS. — These are repositories which have
a more or less flattened or sheet-like form. They may be divided
acotvding to their origin into (i) beds or strata; (z) mineral
veins.
(i) Beds. — The characteristic feature of a bed or seam is that
it is a member of a series of stratified rocks ; the layer above it is
called the roof, the one below it is the Jlo&r. Its tAiclctiaa is the
distance from the roof to the floor measured at right angles to
the planes of stratification ; its dip is the inclination downward
measured from the horizontal; its gtrike is tbe direction of a
horizontal line drawn in the plane of stratification.
The thickness of workable beds varies within veiy wide
limits. The productive port of the copper-shale at Manafeld is
only 3 inches to 7 inches thick ; and one of the beds of gold-
betuicg conglomerate at Johannesburg is only 6 inches to 2 feet
across; we find, on the other hand, the lead-bearing sandstone of
Mechemich, ia Bhenish Prussia, is 100 feet (30 m.), and a bed of
brown coal at Brithl in the same neighbourhood no less than 131
feet (40 m.) thick. Tbe principal bed of slate at the Oakeley
Quarry, Festiniog, is lao feet thick (36-5 m.).
It must not be supposed that the thickness of a bed necessarily
remains uniform. Occasionally this is
the case over a very large area; but *^^- '■
frequently the thickness varies, and
the bed may dwindle away gradually,
or increase in size, or become divided
into two, owing to the intercalation of
a parting of valueless rock ; but, in
8{nte of such variations, a bed is much . - . -- . -.; . .. .—-•-•
more uniform in thickness and com- s^-i^'^-z^^-'-- --S-Ti-m
position than a vein. Fig, i shows
beds of shale, limestone, iron ore and sandstone, anyone of which
may be the object of a mining undertaking.
(3) Teina or LodsB. — Veins or lodes are more or less tabular
or sheet-like mineral deposits, formed more or less entirely since
tho enclosing rocks (ctmnfr^), and either occupying cavities formed
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6 ORE AND STONE-MINING.
ori^D&Ily by fiasures, or consistimg of rock altered in the Ticinity
of fiHBurefi. A simple and typical example of a vein is shown in
Fig. 2, repreeeDting a lead lode in slate at Wheal Mary Ann in
Cornwall.* It is evident that a fissure in the slate has been
filled up by the successive depoeitioo of bands of mineral on both
sidee. The unfilled cavities are called to<Ju (Wales and Isle of
Man), or vuggf (Cornwall). The
Fia- a- definition given above differs some-
what from that of some standard
authors, whose opinions I will quote.
Werner says ;J "Veins are special
tabular mineral repositories which
nearly always cut across the strati-
fication of rocks and so far have a
different lie to them, and are filled
with a mineral mass differing more
or less from the surroouding rocks ;"
and further,^ " Mineral veine may
be more exactly defined by saying that they are fissures in the
rocks which have been subsequently filled up with various
minerals differing more or less horn the surrounding rock."
Game's definition is this:|| "By a true vein, I understand
the mineral oontente of a vertical or inclined fissure, nearly
straight, and of indefinite length and depth." Ton Cotta's is
shorter ;^ "Mineral veins are the contents of fissures," whilst
Grimm says :"• " Veins are fissures in rocks which have been
wholly or partly filled with minerals." Von Groddeck's explana-
tion runs thus :tt " Veins are fissures which have been filled up,"
In Geikie's text-book we find :Xt " A mineral vein consists of one
or more minerals depomted within a fissure of the earth's crust."
IVofessor von Sandberger's idea of a vein is the same :§§ " True
veins, that Is to say, fissures filled with ores." In France ||jl and
Italy^^ similar definitions ju-evail.
* C, Le Neve Foater, " Remarks on tbe Lode at Wbeil Mary Ann, Mea-
heniot." Trnni. S. Qeol. Soc. CoriueaU, vol. iz. p. 153.
a der Eniitthunff iler Qiiage. Freibeifr,
1791. P- 3-
9 lUd.
II J, Came, '■ On tho Relative Age of the Veins of Cornwall," Trana. S.
Oeol. iHoc. GornfBidl. Penzance, 1821, vol. ii. p. 51.
\ DU Lehrt von den BrzUtijeTiitdtten. Freiberg. 1859, p. I02.
*' Die Ijogeritdllen der nutzbaren Mineralien. Prague, 1S69, p. 97.
ft DieLehre von dtn Lagtrttdlteii der Erie. Leipdc, 1879, p. ]1.
XX Trxt Book of Geology. London. 1882, p. 591,
K V. Zoppetti, ArU Mine
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MODE OF OCCURRENCE OF MINERAI^. 7
As long &go as the year 1864,* Mr. Richard Fe&rce brought
forward the ^eory that man; of the tin lodes of Cornwall have
been formed by the alteration of granite, and my own f mve»ti-
gations have convinced me that he is right. The lodes appear
to be bands of stanniferous rock formed by the alteration of
granite in the vicinity of fissures. The tabular mass of tin-bearing
rock 10 or 15 feet thick, called the lode, is traversed by sundry
fissures and passes without any distinct walls or boundaries into
non-stanniferous granite; sometimes the main fissure is a few
inches wide filled with crystallised quartz and other minerals.
This filled'Up crack answers to the common definition of a vein,
but the rest of the stanniferous mass does not. It baa nodefinite
bounding planes, it contains no
fra^^ents of the surrounding fia. 3.
rocks, and presents no appear- ,
ance of having been formed *
by the deposition of minerals '
upon the sides of an open rent I
(Fig. 3), As much of the stan- '*
niferous rock as will pay for ~
working is known as the lode. I
I think the geologist must give
way and suit his definition to
the wants of the miner. It is too much to expect the miner to
give up a term consecrated by uoiversaj usage, simply because
geologists have made the mistt^e of suppodng that all lodes have
been formed on the same plan.
If Cornwall furnished toe only exceptions to the time-honoured
definition of a mineral vein, one would perhaps hesitate in pro-
posing any alteration; but when similar or somewhat similar
cases are met with in other parts of the globe, the necessity for
some change becomes apparent.
Mr. Kendall t says tl^t the hematite veins of the Lake District
(England) are not filled fissures, but are substitutional deposits,
the result of a gradual replacement of the original rock by other
minerals.
Mr. S. F. Emmons § takes a similar view : " I consider it
reasonably certain that a very large proportion of the so-called
fissure-veins in the Rocky Mountain region, notably those in
• R. Fearce, "The Inflnence of Lodes on Rocks,'' Stp. Mneri Auoe.
CoriwxiIL Trnro, 1864, p. 18.
t C. Le Neve Foster, " On the arsat Flat Lode Sonth of Redrath and
Camborne and on some oCber Tui-de[>osiu formed b; the ftlteratlon □(
Onnite," Quart. Jour. Oed. Soc, London, 1878, voL zzxiv. pp. 640-653.
X 3. D. Kendall, " On the Mineral Veins of tbe Lake District," 7>ant.
Mooch. Otol. Soe. Uanchester, 1884, voL ttIII. p. 293.
I R. C. Uills, " Ore Depodts of Bnmmlt District, Rio Qiande Coontj,
Colorado." Condensed for tbe Enginetring and Uining Jotamal, by S. F.
■~ ■ ■■ Eng. Mia. Jmir. 1883, vol. uxv. p. 334.
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8 ORE AND STONE-MINING.
OoloT&do and Mont&na, are simply the alterH,tion, sUunfication,
and laiiiei'&liBation of the country rock along certain planes which
for some reason or other offered exceptionally easy aooeen to per-
colating mineral solutions, and are not the filling up of pre-
existiDg cavities in the rock, as in generally Buppoeed to be the
chaxacteristic of a true fisEure-Tein."
Some of the lodes of Otago, Neir Zealand,* may be described as
belts or zones of auri-
Fio. 4- ferous mica-schiat with-
out any definite bound'
aries ; Fig. 4 shows one
of them,which is worked
at Canton mine. A A is
A a vein of quartz, BB a
channel or zone of dis-
turbed and distorted
hchist, CC a false wall
or plane, along which
there has been a shift-
ing of the strata. The
veia AA, which has
been formed along one
of the lines of fracture
and dislocation, is called
the " indicator," na it
acts the part of a guide
to the miner in his en-
deavours to follow the
auriferous channel ; but
tlie precious metal is not
cou fined to the space
between A and 0.
The question as to
what constitutes a vein
or lode has been more
thoroughly threshed out
in the United States
than elsewhere, because
in some parts of that
country the miner's
title to his property depends upon the definition of the word.
The consequence is that the term "lode" has been defined by
judicial decisions.
In the year 1877, Mr. Justice Field, in the celebrated EuAnumi
V: Etireka case, gave the following interpi-etation ; t " We are of
* Kokard, "The Gold.fields at Otago," Trtmt. Amtr. Iitt. it. £.
Haeting of Jane 1891.
t Transcript ol R«coid. Supreme Coort of the Uniled States, No*. 1031!
CANTON MINE
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MODE OF OCCURRENCE OF MINERALS. 9
opinion, therefore, that the term lode, as used in the Acts of
Congress, is applicable to any zone or belt of mineralized rock
lying within boundaries clearly separating it from the neighbour-
ing rock."
This definition, which has been framed for the practical work-
ing of an Act of Congress, is not a satisfactory one for the
scientific miner, because it wonld include a bed or seam, whilst it
would exclude some of the Cornish tin lodes which have no distinct
boundaries.
Some subsequent decisions cover more ground, for they igntae
the question of shape. Judge Hallett * gave the following chai^
ID the eaea oi Mymanv. The Aspen Mining and SmeUiitg Company :
"It may be said that with ore in Toms and in position in the
body of a mountain, no other fact is required to prove the
existence of a lode of the dimensions of the ore. As far aa it
[vevails, tbe ore is a lode whatever its form or structure may be,
and it is not at all oecessary to decide any question of fissures,
contacts, selvage, slickensides, or other marks of distinction, in
order to establish its character. As was said in another case f in
this court : ' A body of mineral or mineral-bearing rock in the
gwieral mass of the mountain, bo far as it may continue unbroken
and without interruption, may be regarded as a lode, whatever
the boundaries may be. In the existence of such body, and to the
extent of it, boundaries are implied.' "
While quoting these decisions on account of their importance
to prospectors and to holders of mining property in the United
States, I think it wise to adhere, for the purposes of the student,
to the definition I have proposed, and to consider tabular shape
and origin subeeqaent to that of the enclosing rocks as the chief
characteristics of mineral veins or lodes. No doubt a very large
number of mineral veins are simply the contents of fissures;
others are bauds of rock impregnated with ore adjacent to fissures ;
others, again, have been formed by the more or less complete
replacement of the constituents of the original rock by new
min^^.
Veins may occur in stratified or unstratified rocks, and in the
former they usually cut across the planes of bedding.
Like a bed, a vein has its dip and strike ; but as the dip of
veins is generally great, it is often measured from the vertical,
and is then spoken of as the underlie, vrnderlay, or hade. Instead
of being expressed in degrees, the underhe is sometimes measured
by the amount a lode plunges under cover, or away from the vertical,
in a distance of i fathom (6 feet) measured along the dip. Thus
and 1039. ThtSiehmond Mining Company of Ntiiada v. Tlie Eureka Oo«-
toUdatal Miniaii Cotnpamj. Appeal from tbe Circuit Court of the United
State* for tbe dlgtrintot Nevada, p. 604. Ulled Saaaaij 17, 1S78.
* "Tbe Aapen Cue," Kag. Jfi'ri. Jaar. Mew York, voL ilfll. 18S7, p. 31.
+ " Tbe SoingglsT Caw," op. ciL p. aa.
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to ORE AND STONE-MINING.
if AB (Fig. 5) reprmenUalode, and AC = 6 feet, AD being verti-
cal^ draw the line CE at right angles to AD, the inclination is
measured by the relation of £0 to AC.
If EC = 2 feet the underlie is said to be 3 feet in a fathom.
This approaches very cloaely to a dip of 70°, or
Fio. 5. underlie of 30°, whilst i foot in a fathom, for most
* practical purpoeea, corresponds to a dip rf 80", or
underlie of 10°. This method of expreesing the dip
enables it to be determined with a rule or tape. If
AB (Fig. 6) is a lode at the end of a mining tunnel
(levd), the miner has simply to measure the distance
EC — 6 feet, drop a stone from C and ascertain the
distance from D, whore it falls, to E. However,
there is the disadvantage that some miners take the
standard fathom vertically and not along the dip ;
therefore, to avoid any chance of confusion it is
wiser to express the inclination of veins in degrees,
and not by " feet in a fathom."
The bounding planes of a vein, VV (Fig. 7), are called the toaila
or cheekt, and they are frequently smooth and striated, showing that
one side must have shd against the other. These striated surfaces
are called sUckcneides. At the Halkyu mine, Flintshire, the
whole side of one of the levels, for a distance of ten yards, is a
smooth flat polished surface, with small etiite, precisely like the
BCratchings produced upon rocks by the action of glaciers. In
this particular case the striatione are horizontal ; more frequently
they are inclined. The wall above a lode is called the hanging
Fig. 6. Fio. 7.
/^\y
wrt«, AB, the one underneath, the /mrf waU, CD. The rock
surrounding or eucIoeiDg the lode is called the oomUry, EE. I
give this term, not because I wish to perpetuate a mere Cornish
provincialism, but because it has crept into use elsewhere. To
use the words country rock, as is done veiy frequently, is to be
guilty of tautology. I may here remark, once for all, that, as a
general rule, it is best to avoid local technical terms, and as far as
possible employ words which are understood by every one ; but
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MODE OF OCCURRENCE OF MINERALS. 1 1
uome ezpresaions are bo convenient on account of their brevity
that ttey may fairly be adopted into our language. It ia not un-
oommon to find a )ayer of clay, FG, between the lode and the
encloeiDg rocks ; such a layer is called a aelvage, dig (Cornwall),
gouge (U.S.), or alta (California). A large mass of the adjacent
rock found enclosed in the lode is called a hoTK, HH.
Hie valueless components of a lode which surround the ore are
cJten spoken of as forming the gaitguf.. I mention the word in
order to enter a protest against ita use, because, in its passage to
us from the German through the French, it has lost part of its
original meaning. We already have the words veinstone, lode-
ttuff, and twUrix, which are more strictly correct and more eadly
trnderetood than gangue, which, by Englishmen, should be con-
eigned to oblivion.
Veins often continue for a great distance along their strike.
The Van lode in Montgomeryshire is known for a length of nine
miles, whilst the Great Quartz Vein in California has been traced
for a distance of no less than eighty miles.
Veins are of lees uniform productiveness than beds, and are
nrely worth working through-
out. Rich portions alternate ?io 8
with poor or worthless portions. 'astn^^_ — , — f ■"
The rich parts have received *'""'^ "^^^T^t cJ jjJBl
various names according to the « Tmn^jjjpfltiw ' •£ ^T
forms they assnme : Fig. 8 re- "jy^'!j.'.""i.y>^k fJ^~
preeents a longitudinal section 5?;''. . ^^^ '^.^sia*^^ ""
along the strike of a lode, M»d ya.V-*-^ / "'^ "~
the stippled parts are ore-bodies. i>~-.-~-^^ ar .-j^wb
BBB are htttcAes ; A is a large
bunch or cov/rie oj on ; when an ore-body forms a sort of con-
tinuouscoluQuiwehaTeasA(K)E(cAufe,U.8.). Ore-bodies which upon
bong excavated leave chimney-like openings are called pipes (C).
In the United States the Spanish word fxmanza, literally meaning
" fair weather " or " prosperity," is frequently used for a rich
body of ore. The indination of a ahool in the direction of the
strike is called itspiteA and sometimes its dip, though it is better
to restrict this woni to the meaning it receives among geologists.
It is of the utmost importance to the miner to know where he
may expect to &nd a rich ore-body in a mineral vein. Experience
shows that many conditions affect ita productiveness,* viz. : —
1. Intersections with other veins.
2. Nature of the adjacent rock.
3. Change of dip.
4. Change of strike.
* See also, L. Hoinenet, Obterviilhiit ua the Bich Birtn of the Lodet of
OomieaU. Ttaatlated from the French bj J, H. Collins. London and
Traro, 1877-
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la ORE AND STONE-MINING.
(i) InUrKdiona of vtiiit. — AB {Fig. 9) is a vein intersecting
anotlier CD at an acute angle AEC ; it is frequently the case that
there ia an enrichment about the junction E, If the lines A'B',
CD' represent the lodes at a lower
Fia. 9. level, then £E' indicates the line of
intersection, which may he the axis of
a ahoot of ore upon one of them ; but
"^when the angle AEC approaches a light
~~o angle a favourable result is not ez-
«■- . , / pected.
X'-.-.-.V.fJ!(^.. ^ If AB(Fig. 10) represents a section
"'---^^ of a lode along the dip, and CD, EF,
and CH are small veins {ftuders, drop-
pas) falling into it, an increase in the
productiveness of the lode often occurs near the intersection.
(a) Natwe of the adjacent rock. — Few facta are more generally
recognised ttuui the influence of the encloeinfl; rock upon the
productiveness of a lode. I will cite some well-known examplee.
In the Alston Moor district the veins cross alternating beds of
limestone, sandstone, and shale ; they are generally more pro-
ductive in the limestone than in the sandstone or the shale.
At Kongsberg, in Norway, the silver veina are productive in the
fafilbands, that is to say, quartz schist, mica schist, hornblende
schist, and chlorite schist impregnated with iron pyrites and other
metallic sulphides, but are poor where they croits the gneiss. The
lines ABand CD in Fig. 11 represent two such veins in plan; the
portions ai and cd are worth working, but the other parts are not.
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MODE OF OCCURRENCE OF MINERALS. 13
Id the G3'iDpie" gold field, Queenslaad, the Teins are richeet
in certiuD btuids of black shale. Four priodpal belts of blaek
shale have been reco^ised, and their inflnence is so thoroughly
known that " the fact has determined the system of mining oq
the field."
Turning to another part of Anatralia, we may notice the
"indicators" at Ballarat.t These are narrow beds, some only
I inch thiok, parallel to the planes of stratification of tl^
enclosing slate, and full of small cubical crystals of iron pyrites.
Th^ dip is nearly vertical, and they can he traced for miles.
When a quartz vein crosses an " indicator " there is iisually rich
gtdd along the line of intersection. Mr. Charles King says:
" About ten of these ' indicators ' are known within a width east
and west of 1,4.00 feet, and in the case of six out of these, the
quartz crossing them contains, at the line of intersection, exceed-
ingly rich patches of gold, frequently in nuggets many ounces in
weight." Why only six out of the ten indicators should have the
ou-iching effect is not stated.
A third instance of the enriching efiect of a pyritiferous rock
is afforded in the Thames} gold-field of New Zealand, where,
instead of a narrow " indicator," there is a. marked belt of rock,
60 to 80 feet thick, in which the veins prove remunerative. This
"congenial " bed is a felspathic sandstone containing pyrites, and
is probably a volcanic ash. The veins are poor, or die out
altogether on entering the harder diorite or nnderlying slate.
Even in the case of earthy minerals the same phenomenon
occurs. At Wotherton mine, in Shropshire, the bai^t-es vein is
wide and worth working when the adjacent rock is volcanic ash,
bnt narrow and valueless in shale.
Lead veins in Derbyshire, which are productive in limestone,
rarely yield much ore in the toadsUme, an interbedded lava.
(3) Change of dip. — In a given vein the parts approaching
vertioality are often noticed to be richer than those which are
omnparatively flat.
(4) Change of strike. — The veins of a mining district are com-
monly found to have the
scuue prevailing strike. Fig. 12.
Thus the tin and copper
lodes of the Camborne
and Redruth districts,
Coinwall,§ usually run from 8.S.W. to N.N.E., and are spoken of
• R. L. Jack, Annval Beport of tht D^artmtnt of J^inet, Quttniiand, for
Iht star 1885. Briebue, 1S86, p. 58.
t C. Le NevB Foeter, " Mining Indostrles," Eeporti on the Colonial Sec
lunu of the Exhibitiim. London, 1S87, p. i&
J t^. eU. p. 35-
i Henwood. " On tbe MetalUfarons Dapodta of Coiuwall and DevoD,"
TVoM. S. GeoL Hoc. Com. Penzance, 1843, vol. t. p. 250.
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14 . ORE AND STONE-MINING.
as east and west lodes. Slight changes in the direction of the
strike are sometimes followed by Tariations in the prodactive-
neae ; in the case of a lode with an average strike repr&-
seuted by the dotted line a b, it may happen that the parallel
parts ah, c d, ef, are poor, and the parallel parts h e and d e
rich" (Fig. ii).
Too much stress must not be laid upon this question of strike,
because there are so many exceptions to the rule that a certain
strike is favourable. For instance, the two principal minee in
the Isle of Man, Lazey and Foxdale, are wrought, one upon a
north and south v^n, the other upon an east and weet vein, only
a few milee apart ; and at St. Juat, in the extreme weet of Corn-
wall, the mean direction of the lodes is 35* N. of W., and there-
fore quite different from what it is in the chief metalUferous
i-egion ; but with individual lodes changes of strike should not
pass unnoticed.
Formation of Mineral Veins. — Though this book is intended
to deal mainly with the working of mines, a few remarks con-
cerning the origin of veins ace necessary — first, because the
posteriority of their formation is one of their chief characteristics ;
and, secondly, becanse a knowledge of the manner in which useful
minerals came to be concentrated along certain lines may enable
us some day to tredict the precise spots where subterranean richee
are accumulated.
The principal theories are ;
1. fVacture and motion with mechanical filling.
2. Fracture and Injection of molten matter.
1(a) from above.
(b) from below.
(c) from theudes.
4. Fracture and sublimation, or deposition from gases.
(i) Meehanieal FiUi7ig.—l! a rock is fractured, and one side
of the crack slides against the other, a vein of cruEJied material is
formed. If the rock is shale or slate, the vein is a band of day
more or less mixed with uncrushed fragments, and in Cornwall is
known as s-fiookan.
(3) Injection, — Veins formed by the injection of a molten or
plastic rock into fissures are usually known as dykes.
{3) Deposition from Solution. — The lode at Wheal Mary Ann,
Cornwall (Fig. 2), is an instance of a vein formed apparently by
deposition from solution. Many of the common constituents of
mineral veins, such as silica, carbonate of calcium, sulphate of
barium, are known to be slightly soluble in water, whilst the
metallic sulphides can be formed by the reduction of a soluble
sulphate, or by the reaction of a soluble sulphide or sulphuretted
f CbrniroH and Deeon. Bed-
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MODE OF OCCURRENCE OF MINERALS. 15
hytlrogen nptm metallic compounds. Some metallic sulphides are
soluble in alkaline Bolutiona.
Much discnsGion has arisen concerning the place whence the
mineral -bearing solutions came. The theory that the; came
from above finds few upholders nowadays, and the battle rages
principaUy between the advocates of the oKennonal tfaeoiy, <ar
supposition that the minerals came up in solution from very
oreat depths, and the upholders of the lala-al aecrelion theory,
in which it is assumed that they were leached out of the adjacent
rocks and re-deposited in the vein cavity. This latter theory has
been powerfully espoused of late years by Professor IVidolin von
Sandberger,* who has pursued his inveetigatioiis with great
ardour. He shows that small quantities of antimony, arsenic,
bismuth, cobalt, copper, lead, silver, and tiu are contained in
silicates such as augite^ hornblende^ mica, and olivine, which are
essential constituents of plutonic' and volcanic rocks ; and he
concludes that these rocks are the sources from which the lodee
have derived Uieir riches.
Prof, von Sandberger's views have not been allowed to pass
unchallenged, for Prof. Alfred Stelznerf combats his methods of
analysis.
It is naturally impos^ble to affirm with certainty that a given
mineral, such as mica, contains lead for instance, so long as there
is a possibility that particlee of galena were mixed with it. The
absolute freedom of the rocks submitted to analysis, from any
mechanical admixture with pyrites or other sulphides is a necee-
sary foundation-sttme of von Sandberger's theory. It is against
this point that Professor Stelzner directs his attack, and he shows,
by the results of numerous carefully conducted experiments, that
the metals found on analysis by Professor von Sandberger did not
necessarily come from the silicates, but may have been derived
from mechanically mixed sulphides which had resisted his
attempts to remove them. Stelsner points out that the occurrence
in the eounlry of sulpbidee, similar to those existing in the lodes,
may be explained quite as well by their having travelled from the
fissure into the adjacent rock, as in the reverse direction.
With reference to the silver found in the rocks, Stelsner re-
marks that the mica of granite at Sulzbiicble in the Black Forest,
stated by von Sandberger and others to contain o'ooi to o'oo$
per cent. i>f silver, was found to be absolutely free frmn any
traces of the metal when assayed with special precautions at tl^
Mining College of Freiberg.
Under these circomstanoes von Sandberger's theories must for
the present be looked upon as not entirely proven, much as one
* Vntertwiuiitgtii ibtr Ertgiingt. Wieabadeo, i8S2aDd 1S85.
t " Die LattfralMcretloiu-TbmnlB and ihre Bedentung (iir daa Pftbramer
Ganf^biet," Jahrhack dor k.k. Bergakadtmtea eu Leeben und Pfibram und
der £^. uiy. BtrgakadtmU zu Schemnitz, vol. xixrlL
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i6 ORE AND STONE-MINING.
would like to be able to account in bo direct a manner for the in-
fluence of the eoujtiry upon the contents of the lodes.
The views of Mr. Becker,* with reference to the quicksilver
mines of Oalifomia and Nevada, deserve special mention, because
the adherents of both parties 'will probably claim them as support-
ing their theories. To avoid any chance of mistake, I quote ver-
batim : " The evidence is overwhelmingly in favour of the supposi-
tion that the cinnabar, pyrites, and gold of the quicksilver mines
of the Pacific slope reached their present positions in hot soluti<aiB
of double sulphides, which were leached out from masses under-
lying the granite or from the granite itself." Mr. Becker
supposes that the hot alkaline solutions were the products of
volcanic agencies, and he decidedly leans to the view that they
took up the heavy metals in their passage through the granite
it«elf, and not from rocks underlying it.
Even if the ore was not lea«hed out of the immediately adjacent
rocks, these may have influenced its deposition either chemically
or mechanically. It is possible that a certain bed may act as
a reducing agent upon a solution which touches it, and so cause
pre^pitation ; this may be the reason why rich gold has been
deposited where the pyritiferous "indicators" intersect the
B^larat lodes. The mechanical efiect is also very simple. A Assure
formed in a soft rock is likely to be filled up by pieces of Uie
sidra dropping in, especially if there is any sliding of the hanging
wall upon the foot wall ; on the other btuid, if the rock is hard,
the chasm will remain open and leave a space for the reception
of ores. This fact gives a reason for the steep parts of lodes being
sometimes richer than the flatter parte. If a wavy cut is made
in a piece of card or paper to represent the fissure, and the
*' hanging wall " shd down a httle, we have open spaces where
the figure is steep, whilst the " walls " touch where the fissure is
flatter, leaving no room for any deposition of ore to take place.
A wavy crack of this kind may be caused by variations of hard-
ness and fissility, such as happen when shale is interbedded with
limestone ; here the crack will be propagated more readily along
the planee of stratification of the shale than across them. After
a slight shift of the " hanging wall " downwards, the cavitiee in
the limestone become receptacles for mineral deposits, whilst the
crack contains little but crushed rock in the shale.
In a like manner the variation in productiveness noticed upon
a slight alteration of strike may be due to change in the nature
of the " country," which not only caused a deviation from the
general direction of the fisBure, but also afiected its ore-bearing
qualitiea. Here, too, we find an explanation of the phenomenon
called "ore against ore." In Fig. 13 let ABOB, and EFGH
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MODE OF OCOUBRENOE OF MINERALS. 17
represent a plan of two parallel lodes, BC and FO being rich parts;
the miner notices that an improvement in the productirenesB takes
pUce in both lodes when the strike changes from E. and W. to E.
3|° N., and that the rich part, BC, is opposite the rich part FG.
l^is is not surprising if the parts BO and FQ are in a special belt
or Eone, included
between the lines Fto. 13.
HK, LM, capable ->
(rf exerting either a , '.^
mechanical effect " ',
upon the size of the \ '.
Tein-cavity by its "^ ^^-"'^ "
hardness, or a V^^""^ \
chemical effect by a b. >^
its composition. ', ^^^ „
The adjacent rock \ juk""""'''''^*'''
may likewise have , ' " r'. '<
affected the lode by \ \
its porosity or by its \ '<.
impenneability, in J **
the former case by
affording an easy channel for the soludons which brought in the
minerals, and in the latter by interposiag a dam which prevented
or delayed their escape.
(4) SubUmeUion. — The sublimation theory meeto with little
favour nowadays, though certain minerals known as constituents
at lodes are formed in furnaces, or can be produced artificially
from gases. Kearly half a century ago, Daubr6e * produced
crystals of oxide of tin by pasBing a current of stannic chloride
together with steam through a red-hot porcelain tube. One great
objection to the universal acceptance of the sublimation theory is
that many of the minerals found in lodes would be decomposed at
high temperatures.
^ormcUiotu. — -The lodes in some districts are grouped into
diflbrent classes according to their mineralogical characters, and
carefol observations have shown that thoee which are similar in
mineral contents usually agree in strike and in age. Distinctions
of this kind have been skilfully worked out at Freiberg f in
Saxony, where six of these classes or " formationB " are recognised.
Anomaiiea. — Itmust be understood that we cannot ezpectNatore
to make distinct lines of demarcation between the different kinds td
ntineral repositories. Though we may be able to see clearly that
* "BeobetohasnirlapToductioDartidclaUedeqiwlqnesMpdoeimliiiralH
CtlataUinea, putionllirement de raz7(le d'£tala, de I'oxTda ae Utsne et da
QDsrta. ObMTvstionssoirorigioedesaioiwtitaDifiTesdMAJpei." Ann.
Mina, 40 aiiia, toL zri. 184^ p. 139. Chntpt. Bmd., voL zzlx. 1849,
p. aaj, and toL zzz. i85<vp. 383.
t ntAtrg* Berg-vnd HiaUnvefn. Freiberg i. 8., 1893, p. 3a.
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i8 ORE AND STONE- MINING.
a Beam of coal is contemporaneous vitli the enclosiiig rocks, and
that a vein, intersecting Buccessively beds of limestone, shale, and
sandetone, is evidently of later formation, cases frequently occur
in which the origin of the mineral is uncertain.
For example we have the lead-bearing sandstone of Mechemich,
thesUver-bearingsaDdatoQe of Utah, the gold-bearing conglomerate
of the Transvaal. The grains of sand and the pebbles of quartz
are unquestionably of sedimentary origin ; but opinion! differ
as to whether the lead, silver, and gold were deposited originally
with the sand and gravel, or were introduced subsequently by
metal-bearing solutions, which found a. passage through the beds.
It has been shown by Mr. Becker* that ample space exists In an
ordinary sandstone for the deposition of ores. Supposing that
aU the grains were true spheres of the same size, and as closely
packed together as possible, there would be 36 per cent, of inters
stitial space. If this space is evea partly occupied by an ore, the
percentage of metal may very easily be sufficient to render the
stratum worth working. For example, a sandstone with a specific
gravity of 3*35 requires only 37 per cent, of its interatitiaJ qiace
to be filled by cinnabar with a specific gravity of 8, in order to
furnish an ore with 10 per cent, of mercury, about the average
contents of the rock WM-ked at Ahnaden. This 3*7 per cent, is " less
than half the interstitial space in some indurated sandstones
employed for paving streets." In the case of sandstones worked
for mercury, it seems to be quite certain that the cinnabar was
brought in by aqueous solutions long after the deposition of the
sediment — indeed, long after the Bolidificati<m and upheaval of
the rocks.
According to Br. Sorby, the iron of the well-known Cleveland
bed was " derived partly from mechanical deposition and partly
from subsequent replacement of the originally deposited car-
bonate of lime."t
Other cases of more or lees complete replacement may be cited.
We find chalk changed into flint, limestone into chart; and if
" subsequent origin " were the only characteristic distinguishing a
vein from a bed, we should be landed in a difficulty. It will be
found convenient to consider as seami any stratified deposits in
which the impregnated, altered, or peeudomorphou» mass occupies
the position of an original bed, and to call the sheets veing when
they cross the bedding-planes, or occupy a fissure, or have been
formed by the alteration of a rock at the side of a fissure.
UA8SS8. — These are depoeits of mineral, often irregular in
shape, which cannot be distinctly recognised as beds or veina.
Such, for instance, are certain of the red hasmatite deposits of
' "Oeolonof theqniokiilverDcpositsoItbsPaolfloBIope," JfoiMwrcniU
of At U.S. Oeol. Sanrty, voL liil. p. 399. Washington, 1888.
+ Quart. Jour. Oeol. Soc., vol. nxr., 1879, p. 85. Annivcraarv Addrew
of the Fmidant.
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MODE OF OCCURRENCE OF MINERALS. 19
the TTlverstoQ difitrict (Fig. 14),* wbich occupy irregular cavities
in the Carboniferous Limeettuie. They may have been formed
by the percolation of water bringing down iron in Bolution from
overlying rocks, which by gradual replacement changed part of
the bineetone into a mass of hiematite. Other examples of masaee
are the calamine deposits of Altenberg (Fig, i5),t Sardinia, and
Hulberi7 Mine, near Bodmin.
Lombardy, the huge upright "necka" or"ptpee"of diamond-
bearing rock in South Africa, and the granite decomposed in nht
worked for china clay in Cornwall.
Under this head also are included by moet authors the socalled
" stockworka," " reticulated masses " or " network deposits,"
names applied to masaee of rock intersected by so many little
Tuna as to make the whole worth excavating.
Elg. 16 shows a number of steeply dipping strings of casai-
toite, generally only two or three inches apart, intersecting beds
* "BawshreibiiDg der RotheisenenlageretStteD vod Weat Cumberland
nnd North Tinnmnhire," Siahl uitil EUen, 2 JafargaoK, No. iz, Plate VI.
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30 ORK AND STONE-MINING.
of slate. The mass of rock penetmtod by this network of tittle
tin veins is 300 yards long by more than 30 yards wide, and the
whole of the stumiferous stooe is quarried and stamped.*
XXAUFIiBS. — These abstract definitions are not sufficient ;
the student should see how they can be applied to particular cases ;
and I now propose to give a series of examples of the modes of
occurrence of the moet important minerals. As the same mineral
may be foand in a bed, a vein, or a mass, it is simpleet, for the
pnrpoeeB of the miner, to classify these examples alphabetically.
I tlierefore arrange the information about tin, for instance, under
one head, instead of separating the tin veins from the stockworks,
and these from the alluvia. The minerals to which I propose to
refer are:
Alum, amber, antimony ore, arsenic, asbestos, asphalt,
bar]rtea, b(»«z, boric acid, carbonic add, clay {including china
clay, fipB olay, fuller's earth, potter's clay), cobalt ore, copper ore,
diunonds, flinty freestone, gold, graphite, gypeum, ice, iron ore,
iron pyricee, lead ore, manganese ore, nitrate of soda, oohre, oil
shale, oK^erito, petroleum, phosphate of lime, potassium adta,
quicksilver ore, salt, silver ore, slate, stone, strontium sulphate,
sulphur, tin ore, zinc ore.
Alam. — The alum-stonef obtained at Allumiere and Tolfa, near
Oivita Yecchia, occurs in very irregular veins, which are supposed
to be due to the action of heated water and sulphurous gases upon
the felspar contained in trachyte.
An important deposit of alunite has lately been discoTerod^
in New South Wales, at the Bullahdelah Mountain, which
rises up from the bank of the Myall River, a tributary of
Fort Stephens. Marked cliSs, overlooking the river, consist of
alunite in varying quality, ranging from pure alunite to a mineral
in which there is as mudi as 40 per cent, of silica. The deposit
ia traced for over a mile in length and nearly three-quarters of a
mile ut breadth, the thickest band of stone being from 60 to 70
yards in width. The average composition of the rock now being
worked is as follows :
Wat«r ;-8o
A'""*'"' 34 '70
Oxideof Iron r'oo
Fota»h 6-10
Sulphnrlc acid 33'30
StUca 18-to
* 0. Le Neve Foster, "On some Tin Stookworbi in COTnwall," Quart.
Jour. OtoL Soc, vol. nxJT., 1878, p. fijj.
+ A. K. de la OrBnga, Le TVaehtU a3la H^a e lefmtnaaioniaBumini/ere.
Borne, iSSr.
7 HS. information from ICr. S. Herbert Ooz, AR.8JI., the discoverer ot
the alnnlts^
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MODE OF OCCURRENCE OF MINERALS. 21
The sorroundiog locka belong to the Carboniferous sjabaat of
Xev South W&les, and it is supposed that the alonite has been
formed by aolfataric action upon dykes of a felsitic rock.
Aiaber. — This fossil resiu is found in a bed of Tertiary age,
which ezt«ndB aiong the shores of the Baltic from Western
Bnsda to Denmark, The principal workings are about halfway
between Memel and DantEig,and the amber is obtained by diving
and dredging in the sea and by ordinary mining inland. After a
storm pieces are cast np on the shore. The stratum containing
the amber ia known from its colour as the " Uue earth."
Antimony,— ^ Antimony ore usually occurs in veins. In York
Counly, New Brunswick,* the veins are from a few inches to
6 feet wide in Lower Silurian slate. The veinstone is white
?[uartz, calcite, and iron pyrites in small crystals. The ore raised
rom the mine contains about 10 per cent, of Btibnit«.
Araenio. — The white arsenic of commerce is mainly obtained
from mispicket, which is either mined by itself or more commonly
in connection with the ores cJ copper, tin, or gold. It is there-
fore in most casee a by-product in the preparation of these ores
for the market.
AsbestoB. — The asbestos of commerce is in part chrysotile and
in part thefibrousvariety of hornblende. ItalyandCanadaarethe
chief sources of supply, and in both countries the mineral is found
inveinsin serpentine. The principal Italian mines arein theSuea
and Aoeta valleys and the ValteUina.t In one of the mines in
a tributary of the latter valley the rock is " cut in every direction
by thin seams of asbestos, which seem to start a£ from a centre
and spread out in every direction, and these again are traversed
by thin seams both horizontally and diagonally. Entering into
the rock, these seams generally converge to a centre, where
the various thin seams unite themselves, and here a pocket of a
ton or a ton and a half of asbestos may be found, and then all
appearance of its presence ceases. Continuing to work inwards,
the seams generally re-appear and spread themselves out as
The most important of the Canadian quarries are situated in
the townships of Thetford and Coleraine, in the province of
Quebec. A belt of serpentine runs through the district, and it is
intersected by innumerable small veins of chryeotile, varying in
width from a mere knife-edge to about 6 inches at the most,
the fibres of the mineral running almost at right angles to the
walls. The common width of the veins is from i to 2 inches, and
as they "cross and recroes each other in every direction and at
• B. a. J., vol. iri., 1873, p. 7 ; and S. a. k. Z. 1874, p. 337.
f Jamet Bo;d, "Ajbeatoi and its ApplioatioDs,'' Jour. Sue. Artt,
Tol. xzzIt. (1886), p. 583. J. A. Fisber, "HiDieg, Msnnfactnre and Uwa
ol AjbewoB," 'Fraat. Intt. ittiriiie Ehu., vol. iv., 1892.
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23 ORE AND STONE-MINING.
eveiy angle,"* the whole of the enclosiDg rock hue to be quarried
in order to get out the asbestoa.
Asphalt. — The variouB modes of occurrence of asphalt or
bitumen have been described by Malot and Greene,]: and the
following table is made up from their works :
suk. LoctUtiH.
ITtHons . , Fitoh springs !DAlabuua,Fnaoe,
VuMsnela.
BoUd . . Dead Sea, Cnba, Texas, UUh.
3. Hlzed with euthj matter . Pitch I^ke, Trinidad.
3. Mixed with sand . . CaUfoniia, Franoe, Utah.
(bltamtnoas ucdttoue)
4. Impragnattng limeatone . Colorado, Cuba, Fiance, Hexloo,
(UtumlnoQi limestone) SicUj, Bptin, Switzerland.
The nearly pure asphalt does not occur in sufficiently large
quantities to be worked on a commercial scale, and the Fitcb
l^ke of Trinidad,§ long known as a natural wonder, haa not
been utilised to any great extent until of late yeare. The lake
occupies an area of 99 acres, and is on an average from 20 to 30
feet deep. Its surface is not one continuous sheet, but is broken
up by pools and channels of rain water ; the asphalt is nearly
everywhere solid enough to walk on. The crude asphalt has the
following composition :|j
Pneant.
BitnioeD 34
Water 30
Clay 36
"The bituminous sandstone of California is found in large
quantities at various points between Sau Frandsco and lios
Angeles. It contains about 12 to 18 per cent, of bitumen, and
the rest is quartz sand, in grains about one-tenth of an inch in
size.'II
We now come to the bituminous limestone. Val-de-Travers,
in Switzerland, and Seyssel, in France, are the most important
sources of this rock for paving purposes. At Seyssel there are
no less than seven beds of bituminous limestone, varying from i o to
2o feet (3 to 6 m.) in thickness. One analysis of the rock** was as
follows :
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MODE OF OCCURRENCE OF MINERALS. aj
Bitameii £70
Clay 3-00
Peroxide of iron 3'fo
Lime 4J'0O
UaguesU 3-30
Snlpbnric acid 0-20
Phospborio acid o-aa
Carbonic aoid, water and loss . 38'6o
99'6o
BaryteB. — This rnin^^I frequently aocompaniefl lead ore, but
veins ar« Bometimee worked for it alone, as at Wotfaerton in
Shropshire.
Borax. — Tbe American borax depoeitB* now beinf worked are
sitoated in a vast depression known as the Great BasiD, which
exists between the Sierra Nevada on the West and the Rocky
Mdantains on the East. Much of the region is a desert wi^
rirers and lakes which have no visible communication with the
ocean. The rivers lessen in volume gradually fixim absorption
and evaporation, and end in lakes. During the rainy season soda is
dissolved out of felspars contained in tbe lava which covers much
(tf the country, and in the dry season the salts of soda crystallise
out at the sarface in the form of efflorescent crusts, 12 to 18
inches in tinckuees. The rain dissolves the crust, which is cttrried
away in solution into the rivers, and eventually into depressions
which form saline lakes.
The two principal deposits, known as Borax Lake and Teel's
Marsh, were discovered in 1873 ; the former lies in the Mojave
desert in Califomia, 450 miles S.E. of San Francisco, and the
latter is in Nevada. Tbe Borax Lake is oval in shape, its
greatest length and greatest breadth being 11 miles and 8 miles
respectively (Fig. 1 7). The greater part of the lake is covered
with a hard crust from a few inches to several feet in thickness,
consisting of various salts. On the top of this crust there is
usually white efflorescent matter mixed with sand, whilst under it
is black mod containing much iron sulphide, saline matter, and
sulphuretted hydrogen.
Tha lake may be divided into three sections, containing respec-
tively: (i) borax, (2) bicarbonate of soda, (3) common salt.
Near the centre of ue borax section, an area of about 300 acres
is covered with water, i inch to i foot deep, and the mod under-
neath is full of large crystals consisting of carbonate of soda and
common salt, with a large proportion of borax. The ground
around this " crystal bed " is a dry hard crust containing car-
bonate and sulphate of soila and 1 per cent of borax. Upon this
hard crust there is efflorescent matter containing on an average :
* C, Na[dei Hake, " An AoooDUt of a Boiaz Lake in California," Joum.
Sat. Chem. Ittd., vol. viU. (1889), p. 854.
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OEE AND STOM&MINING.
1
Band
Sulphate of soda
Common salt ....
Carbonate of soda , . , , ■
Boru
This surface efiloreeoence, wbicli is about an inch tbick, is
scraped off with shovels and swept into windrows, leaving space
enough between them for a cart to pass. When the surface has
been cleared, the moisture finds its way up again by capillary
action and is evaporated by the sun. The formation of the
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MODE OF OCCURRENCE OF MINERALS.^ 25
effloresoence is allowed to go on for three or four years, and then
the new crop is scraped off. The sand ia blown on by high
periodical vesterly winds.
The qneetion naturally arises : Why is thn borax mainly con-
fined to one part of the lake ! It appears necessary in order
to produce the efflorescence that the crust should touch the
water, so as to get a supply of the saliae matter. The borax
section is the lowest part of the lake, and the bard crust dipe into
the water. When the level of the water is low during a very dry
season, the fonnati<»i of the efflorescence goes on slowly or ceases
altogether. In addition to borax there are sundry depoaits of
borate of lime in the same region.
Borlo Aoid. — Boric acid ia obtained in considerable quantities
tnym gaseous emanations which come to the surface through in-
nomwable fissures, probably dislocations, in the Eocene and
Cretaceous rocks of Central Italy.* The best known localities
are the four contiguous parishes of Pomarance, Castelnuovo di
Val di Cecina, Massa Marittima, and Uontieri, in the province of
Pisa. A pit is dug around any natural " steam-puS'," or " blower "
(«Q^on<), water is run in, and the steam and other gases, which
t>oil up through it, leave a little boric acid in solution. The
gaaes that eecape are steam, a good deal of carbonic add and
nitrogen, some oxygen, and a little sulphuretted hydrogen. The
very weak boracic solution is concentrated by heat derived from
eome of the steam-puffs. The total production of the provinces
of Pisa and GroBseto in 1891 was 1775 metric tons of boric
add, worth ^£^35,500, and ^056 tons of borax worth ^£53, 456.
Carbonic Aold. — -LiqueQed carbonic add is now a r^^ar
article of commerce, and Oermany has taken the lead in utilising
the natural supplies of the gas. In 18S3 a bore-hole was put
down for carbonic add at Burgbrohl,t near Andernach on the
Rhine, and since then others have been made at Obermendig,
Tonnistein, Hijnningen, and Gerolstein. All have been successful ;
they show that the subterranean supplies of carbonic add are very
plentifol, and that in places where the gas is already known to
issue, nothing but a comparatively shaJlow hole is needed to
increase the quantity veiy considerably.
At HOnningen, about five-eighths of a mile (i kilometre) from
the Rhine, an emanation of carbonic acid gas had long been
known, and was piped off to compression works before any boring
bad been made. The rocks in which the carbonic acid occurs
at Hfinningen consist of greywacke and clay-slate, jrith vein-like
massea of quartz ; they belong to the Xxiwer Devonian or so-called
* Jervin, Otada oRt Acqae Minerali d'ltaHa, Turin, 186S, p. 13I ; and
I Ttmri lotterranei dtiT Italia, Tnrin, 1874, p. 427.
t 'EeiiBiei,SUziatptberielUeder nitderrlteinUdititGetcHKhnflfarNidur-wtd
Haliundt ia Bonn. Heeting of Jolj 9, 1S88.
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i6 ORE AND STONE-MINING.
Coblentz beds, and the bore-hdes at Burgbrohl, Obarmendjg, and
TOnaistein have been pat down in strata of the same age.
The USnoingeii hole was bored with a diameter of 13 inches
(33 cm.) to a d^th of 230 feet (70 m.) from the surface. The
first water containing carbonic add was met with at a depth of
93 feet {28 m.), and it stOl remains at this level. The quantitj
of gas is greater than was given off bj the old emanation at
the surface, and is reckoned to be 500 litree (nearly iS cubic feet)
per minute, corresponding to 720 cubic metres (35,438 cubic feet)
of gas, or I kilog. (3*2 lbs.) of liquid carbonic acid in tweoty-four
hours.
The Hdnningen spi-ing differs from eome others by the fact that
at a depth of 230 feet (70 m.) the water is already at a tempera-
ture of 73° F, (22" C), and probably a higher temperature would
be reached if the hole were deepened. A second hole has been
bored to a like depth by another company at a distance of 50 feet
(15 m.) from the first, and a good supply of gas has been
obtained.
At Gerolstein the bore-hole passed through alluvial gravel into
solid dolomite, and was stopped at a depth of 156 feet (47^ m.)-
It seems probable that the hole has penetrated into a wide fissure
filled with loose fiagments of dolomite. The water which fi.0W8
out contains such an excess of carbonic acid that it froths up at
the surface. The quantity of water coming up is S476 cubic feet
(240 eb. m.) ill tweuty-four hours, with an estimated minimum of
1060 cubic feet (30 cb. m.) of carbonic acid gas per hoar.
Though natural outflows of this gas are common, especially in
volcanic regions, the number of places where they are utihsed
commercially is small. In addition to the German localities, I
may mention two places in Italy.* There are springs of water
impregnated with carbonic acid and emanations of the gas at
Cinciano, in the Yalle d'Elsa, province of Siena, which are used
for making pure bicarbonates of potash and soda from the crude
carbonates, and also for making white-lead from the acetate,
the gas beiug pet-fectly free from any sulphuretted hydrogen.
Similar blowera {eoffioni) at Montioae, near Arezzo, are em-
ployed for the latter purpose.
Clay (including common clays, china-clay, fire-clay, fuller's
earth, pipe-day, potter's day).
As a rule, chty occurs in the form of stratified deposits, and this
is the case with an important British day, the fire-day of the Cool
Measures, which is found iu beds sometimes several feet in thick-
ness and usually under a seam of ooal. The coal is often too thin
to be worked and may be only i inch thick, but both coal and the
underlying fire-clay may be worth working together. Various
beds of clay of Secondary and Tertiary age are dug in England
* JerTis, Owda aUt Arqup. M!ner<di iFItdlla. Tarln, 1868, pp. 54, 63.
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MODE OF OCCURRENCE OF MINERALS. 27
for making pott^7, drftin pipes, and Portland cement. Tbe beds
of fuller's earth near Bath are of Oolitic age, whilst those which
are mined in Surrey belong to the Lower Oreensand.
The china clay* of Cornwall and Devon exists in irregular
deposits of a totally different nature ; they consist of granite
deoompoeed in ntu, not by atmoapheric agencies as is often
stated, but far more probably by hydrofluoric acid brought up
by deep-seated fieeures. That the decomposition was due to the
veins or fissures seems evident from the fact that the altered rock
occurs in bands adjacent and parallel to them. Where the
veins are numerous a very large mass of china clay may be found,
extending for a width of a hundred or more yards, and a length
of a quarter of a mile or half a mile along their strike; the depth
to which the alteration of the granite continues is quite unknown.
The veins are often tin-bearing, and workings for tin have led to
tbe discovery of china clay; indeed the two minerals may be
worked together. The altered granite considts of quartz, white
mica, sometimes a little gUbertite, and felspar which has been
more or lees completely converted into kaolin. This last mineral
is easily separated when the soft rock is washed down by a
current of water, for it is so finely divided that it is the last to
Rettle when the milky stream is led into depositing pits.
Cobalt. — The cobalt ore worked at Skutterud in Norway is
found in certain bands of quartz
schist and mica schist which Fig. 18.
contain sniall particles of cobalt . _ » is ft: .»
glance, sbutterudite, cobalti-
ferouB mispickel, ordinaiy mie-
pickel, iron pyrites, and other
metaUic salphides.
The accompanying figure (18)
illustrates what I saw at Skut-
terud some yean ago ; a, a, a,
are bands of mica schist with
little or no cobalt ore ; b, b, are
bands of quartz schist containing fc^ O a. o <fc- c £t^
the cobaltic minerals dissemi-
nated through them, and c, a cobaltifereus band of mixed quarts
schist and mica schist.
The rocks appear to be altered sedimentary strata, and the
deposits most he spoken of as beds. The strike is "S. and S., and
the beds dip at a very high angle to the east. Quarts schist is
the rock most likely to be cobaltiferous, the mica schist may be
also worth working, but hornblende schist is poor. The cobaltic
beds are commonly two or three fathoms wide, but a number of
• J. H. CoUint, Th» SerubarroiB Oranite DUtrkt. Truro, 1878. And,
"On the Natare and Origin of Clays: the Composition of Kaolinite,''
JfiN. Mag. London, toI. vu. (1S87), p. Z05.
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38 OEE AND STONE-MINING.
adjacent beds may produce a much {greater thickness of oobalt-
iferooB rock.
In New Caledonia* the mode of occurrence is totaUj dtfierent.
Fjg, 19.
3 fitH i/GtmmicImii
The cobalt is found as a hydrated oxide, without a trace of
sulphur or arsenic, intimately associated with hydrated oxide of
manganese, in irregular " pockets" of red clay in serpentine. In
Fig. 19 S is the serpentine and A the red clay; a a represent
veins of chromic iron in the serpentine ; a' a' is a little stratum
of fragments of chromic iron derived from these veins, whilst 6 6
are beds of cobaltiferous manganese ore in the clay. The ore
lying about on the surface or obtained from these pockets has from
aj to 3 per cent, of cobalt.
At Knyl, in Flintshire,t there is a curious irregular cavity in
Fia. 20.
■P.t mmm>mmmij*m>m''^
the Mountain Limestone filled up with red clay which encloses
small lumps of asbolane. This deposit was worked on a small
scale for sevend years.
Copper. — The most important copper mines of the world
* Levat, " M6inoire stir les prt^rte de la mctallnTgie do niokel,"
rin«f. 9e akM, ToL L p. 147.
t Tran». H. Cbrnukiu GtoL S(x., toI. z. p. 107.
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Fennian
MODE OF OCOURBENCE OF MINERALS. 29
Dowadaya &re those of Monefeld in Oermany, Bio l^to and
Thands in Spain, San Domingos in Poitugtil, Lake Superior,
Arizona and Montana in the United States.
Germany. — Copper mining has been carried on near Maasfeld, in
the PruBsian province of Saxony, since the commencement of the
twelfth century, and the district is specially interesting from the
factthattheoreis found in a bed or seam, which can beworkedwith
profit in spite of its thinness and comparative poverty in metal.
The Mansfeld district (Figs. 20 and 21) is mainly occupied by
the rocks of the following formations : —
Tiias 3. Bunter Sandetone.
( X. Zechstein.
' ( I. Rothliegendes.
(i) " Das Bothliegende," or the red floor, is the old miners'
name for the sandstone and breccias lying almost immediately
below the bed of cupriferous shale. In contradistinction to the
ore-bed, it is also called " das TodtUegende " (the dead floor), tt
can always be distinguished by its characteristic red colour. One
of its most constant beds is the so-called " porphyry con- -
glomerate," constating of pebbles of milk-white quartz, hard
siliceous slate, and grey and reddish porphyry,
(2) The Zechstein formation consists of three divisions. The
lowest division comprises the " 'Weissliegendes,'' the bed of copper
shale and the Zechstein. The middle division consists of the
anhydrite or older gypsum, or of its equivalent the " Bauchwacke,"
" Asche," " Bauhstein " and Stinkstone ; the upper division is
made up of vari^ated clays with intercalations of gypsum, the
reeidnee left when some of it is dissolved away ^Asche), and cal-
careous or dolomitic concretions.*
The " Weissliegendes " is petrographically like the " Rothlie-
getides" below it, and is looked upon by many as merely an
uppermost bed deprived of colour. Above, it with great
r^olarity comes the ore bed, a blackish, bituminous, marly shale,
about 15 to iS inches thick.
The ore of the shale bed is usually disseminated through it in
the form of fine particles {Speise), which impart a metallic glitter
to the surface of eroes-fractures. AgoldenyellowcolourincUcates
chalcopyrite, a bluish and reddish variegated look, bomite, and a
steel grey, seen more rarely, is due te cop^ier glance ; whilst a
greyish yellow denotes a predoininatice of iron pyrites, and a
leadan grey, galena. The following minerals also oocur : cinnabar,
blende, kupfemickel, speiskobalt, and compounds of manganese,
molybdenum and selenium . Oxidised ores are found at the outcrop,
* The flgnres and some of the details coDcemlog the Mansfeld mioea are
bonowed ftom a pamphlet entitled. " Dei Knpferschieferbergban and der
Httttenbebieb tnt VerarbettODg dei gewonnenen Minern in deu befden
KsniMdeT Kreisen der PrensaischeD Frovlni Sacbsen." Eisleben, 1889.
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3© ORE AND STONE-MINING.
and are naturally of secondary origiD. In addition to the finely
diseeminated grains, there are often smalt etrings of tximite and
copper glance, generally parallel to the bedding, and thin coatings
of copper glance, bornite, chalcopyrite, and native silver along tne
Skttion ot Bddabd It. Shapi.
ZtcMlin .
Copptr Shalt
Ralktitgtiidei
Cimtlimtratt
Rolklicttnda
Tfcudct ivitA MiJafij'rt
planes of bedding or in croes joints. Finally there may be small
nodulee of copper ore lying singly.
The whole of the bed of copper shale is ore-bearing ; bnt, as a
rule, only the bottom 3 or 4 inches are rich enough to be worked
with profit. Occasionally 6 or 7 inches can be taken, and in ex-
ceptional cases the whole of the bed goes to the smelting works.
Although there are minor variations, the shale is fairly regular
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MODE OF OCCURRENCE OF MINERALS. 31
Hs r^ards ore-bearing when dealt with on a lat^ scale. On an
average, in the true Mansfeld district, between Gerb^tedt and
Eialeben, it contaios 3 to 3 per cent, of copper and 163 oz. of
silver to the ton of copper (5 kiL per metric ton).
The importance of the copper ahale will be appreciated from
the fact that in the year 1S88, 14,178 persons were emplojred at
the mines, or more than all the miners of Cornwall and Devon.
The output of ore was 469,716 metric tooe, which produced
13,600 metric tons of refined copper, and 77,950 kilogrammes
(208,845 Troy pounds) of silver.
Spain and Portugal. — The famous mines of Bio Tinto,*
Thartds, and San Domingos are contained in a great metalliferons
belt of conntry, 140 milee long by 30 miles wide, stretching
across the province of Kuelva in Spain and into Portugal. The
rocks consist of slate of TJpper Devonian age, often altered
locally into jasper, talc schist, chiaetolite schist, etc., with great
intrusions of quartz and felspar-porphyries, diabase, quartz-
syenite, and granite. The geological horizon of the slate has been
determined by finding Poaidonomya Beeheri, P. actUicoata, a
goniatite allied to G. tuhwloatut and other fossils. The strike of
the slates is about 15° to 25° north of west, and the dip either
* CoUiot, " On the GeoloKj of the Rio Tinto Minea, with some General
Bemarke on the Fjritic B^on of the Sierra Morena," QuaTt. Journ. Ocal.
/tbc, voLxU. (1SE5), p. 34s
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Via 33
32 OBE AND STONE-MINING.
vertical or at a high angle to the north. Through having the same
general strike aa the slate, the masses of porphTiy may appear to
be iaterstrati£ed, but a close examimition of the junction proves
them to be intrusive.
As shown by the map (Fig. 32), there are four principal
depodtsof pyrites at Bio
Til to viz., the North
Lode, the South Lode,
the San Dionisio Lode,
and the Valley Lode.
They all occur at or
near the junction of the
porphyry and the slate ;
and they are supposed bv
Mr CollinB to occupy
cavities produced by fis-
sures On the other hand,
the somewhat similar
deposit of the Bammels-
berg mine in the Hartz
18 now unanimously con-
sidered by geologists to
be of sedimentary origin,
Ja and to be strictly con-
" formable to the surround-
ing beds of slate.
The South Lode, the
one meet largely wrought
h therto, is sometimes as
much as 450 feet (140 m.)
wide, and is known along
the strike for a distance
of about a mile, or, in-
deed, for two miles if tiie
San Dionisio lode is cson-
sidered to be an extension
of it to the west. Fig.
the South Lode at San
Inooente shaft, and Figs. 34, 25, and 26 are taken at points a
little to the east.
Ikdez roR Fies. 33 to 26.
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MODE OF OCCDREENCE OF MINERAIS. 35
Figures * 3 7 and 28 show the curious maimer in which the San
Dionioio lode swells out suddenly at a depth of about 150 metres
fnnn the surface, and actually attains the enormous width of 300
metres. A, is slate ; B, porphyry ; C, cupreous pyrites ; D, iron
ore, the "gozzan" or iron cap of the lode. The slate is dipping
steeply towards the lode, as indicated by the lines denoting planee
of bedding. The hatching of C itaelf does not repi-esent any
struotnre. It will be interesting geologically and important
commerci^y to watch the further development of the workings
upon this remarkable lode.
The character of the ore varies a good deal. Iilr. Collius
names fourteen different kinds. The principal are : (i) Ore
treated for copper on the spot, and (3) that which is exported.
The former consists of fine-grained and oonopoct iron pyrites
with I to 3^ per cent, of copper, existiog as copper-pyrites
minutely disseminated throughout the mass, and the latter only
differs by being richer in copper, and containing up to 5f j*^*^
Littde veins of copper-pyritee, embescite, and occasionally
copper-gl&nce, more or less
mind with iron - pyrites, Fio- *7-
quartz, blende, and other
minerals, traverse the mass,
and there is sometimes a
compact mixture of galena,
blende, chalcopyrite, aud
iron-pyrites resembling the
" bluestone " of Anglesey.
Few mines in the world
are of more importance
than Rio Tinto. The quan-
tity of ore extracted in
iSgif was 1,403,063 tons of
21 cwt., of which 995,151
tons were for local treat-
ment and 406,913 for shipment to Great Britain, Oermany,
and the United St«t«e. The average percentage of copper was
2-819.
The depoeite of iron ore marked on the map are horizontal
beds, probably formed at the bottom of lakes in Miocene tunes.
The or« is brown hnmatite, with varying proportions of silica. .
The sections show that the upper part ctf the pyritee has been
converted into a goszan ; much of this is a good iron ore, and is
being stocked for disposal at some futura time.
• From diawliigH kindly supplied hj Mr, Jamea Oiborne, the cenend
nuoami of the Ko Tinto HinM.
t mo Tlnto Co. Ltd„ Twentieth Amiual Beport, April 1893,
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34 ORB AND STONE-MINING.
The Tharaia and Ban DomingoB mines are likewise vast under-
takings, and the total imports of cupreous iron-pyrites into this
country alone from Spain and Portugal in 1891 amounted to
608,000 tons, worth over one million sterling.*
Fio. iS.
United States. — Crossing the Atlantic, we will now turn our
attention to the minee on the southern shore of Lake Supericnr,
which are remarkable for their productiveness, and which aire
equally attractive to the geologist and to the miner.
The copper-bearing districtf lies on a long peninsula, 1 5 to 30
mUes wide, with a north-easterly trend, which projects into Lake
Superior (Fig. 29 i) some 60 miles beyond the general run c^
its southern shore, and terminates in Keweenaw Point. The
western haJf of the peninsula is formed by rocks belonging to the
Keweenaw Series, considered by many to be younger than the
Huronian and older than the Cambrian. They consist of sand-
stones and conglomerates, interstratified with flows of eruptive
rocka of various kinds.
The beds dip to the north-west, at an angle of 23° in the
northern part of the mineral district, and in going south the
dip increases to 56°. The outcrop of the actual copper-bearing
part of the series occupies a belt of country fnom 4 to 5 miles
wide.
" Mbt. Slat, for rSgr. London, 1891, p. 59,
+ K D. Irving, " The Copper- bearing Rocks of Lake Sapeilor," United
StaUi Qeol.Sur-ety. Washington, 1S83. Donslu, " The Copper Reaoorcea
of the United Btates," Trant. Atatr. ItuI. M.E., vol. xli, 1890, p. 679;
^d Jour. Son. Aril, voL zlf. 1893, p. 39.
} Engi-neerin^, vol. I. 1S90, p. 553; and Qoide-bcok prepared for the
mcanben of the Ixoa and Steel lueUtale, 1890.
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MODE OP OCCUBRENCE OF MINERALS.
35
A. Bed8^
The modes of occurrence of the copper may be classified as
follows :
1 . Copper-bearing conglomerate and sandstone.
2. Copper-bearing amygdaloid.
B. Vkhb."
A. (i) The deposits of the first class are beds of cooglomeiate
and sandstone impregnated with native copper. In most cases
the cupriferons beds are interstratified with diabase fiowe ; but
Fig. xg.
^p^^
/
nmmauKU
^r ^ .^
V )
^\ / /''
%' ^'
£ -'" /^.,<*
/v"
J^^
ff /tr^
^,^
il^v
V^fe»
^^
W\
«JijHB^3
\
■'^Xs^/i
_-#.-•
/ 1
w/^
»■ f
..•^■■«r
tbis oonneddoD between the proximity of diabase and the presence
4^ copper is not universal. The copper oocurs as the cementing
material of the pebbles and grains dl sand, and also replacea the
pebbbe themselves, large stones several inches or even a foot in
diameter being converted into the native metal The copper has
evidently been deposited from aqueous solutions. By far the
greRtest proportion of the I^e Superior copper is obtained from
these c(»iglomeratee.
A. (2) The cupriferous amygUaloids are portions of the old lava
flows, and are not strictly speaking beds as defined, though it is
convenient to call them t^ that name.
Often tiiey are highly altered and have lost all sign of having
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36. OBE AND STONE-MINING.
oooe been vesicular; the native copper vhioh they oontain mogt
have found its way in long after their eruption.* It is usually
very irregularly distributed, and tbe parts rich enough to be
worked may he surrounded by much poor or barren rock. The
presenoe of epidote and calcite ie regarded as a good indication
for the proximity of copper.
B. As the cupriferous lava beds and conglomerates are locally
called " veins," it in necessary to say that tbe real veins run in
a direction at right angleo to the general trend of the beds, and
are almost vertical. Their ububJ width is from one to three
feet, but it may become as much as lo, 20, and even 30 feet.
They are largest and richest when they have amygdaloid or loose-
textured diabase for their walls, and they become pinched up and
worthless in the compact greenstone or sandstoDe. To a great
extent they consist of alteral rock, and are an instance (d lodes
formed by replacement of the " country." According to Irving
these veins were formed by copper-bearing solutions which found
a path through zones of fissured rock, instead of following certain
easily permeable beds, The copper is in the native state, and
generally in massee of considerable size, the largest found weigh-
ing nearly 600 tons.
The following statistics relating to the Xiake Superior mines
are taken from a guide-book prepared for the membero of the
Iron and Steel Institute in 1S90.
Hini«ari(liie.
depo.lt.
s
Inioek
•tampfd.
"SiSt
ADonci . .
Conglo-
merate
1700 j ia6,I3S
B81
..,«
0-76
Cklaaetknd
3750 ! 807.91a
*4.334
3P'.53S
3-01
33,359,oot>
PMliixDlm .
6co
368
196.707
S.S'S
16,624
3 36
AUuitlc. .
Amredi-
lold
,»o
288,040
.J49
33,786
0-66
Sf»,aoO
Copper Pall.
ss
_
435
.0.7B9
X
100000.
Fmnklln .
186.740
3,173
3'.96i
96o!ooo
Hnron . .
1800
159.333
1,109
.=,6sa
0-98
76.54'
960
',384
B0.000
Oueola . .
ai6a
aoB,399
3,63.
35. 3H
1-39
.,333,300.
QnlDcr . .
3070
"3,to8
53.350
373
5.350,000.
Cutnl . .
V^m
3900
HoslJ;
^"6^
»<'.3S5
1,930.000.
miu*
Aa will be men from these figures, the Calumet and Hecl»
mine is the most impmrtant on lAke Superior. The bed of
oopper-bearing conglomerate is from 8 to 25 feet thick, and
• Irving, Op. dt. p. 431.
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MODE OF OCCUREENCE OF MINERALS. ,37
about 13 feet on an Average- The dip is 37}° to the oorth-WMt.
The depth of the mine which k given ia the table is measured
on the dip, and would be about 3,280 feet if measured vertically ;
but these figures are now greatly exceeded, and shafts are beiux
sunk which will enable the Calumet and Hecla and the TamarmA
mines to be worked to the enormous depth of 5000 feet.
The very low percentage of copper in the Atlantic amygdaloid,
which nevertheless is worked at a profit, is remarkable; but,
unlike the amygdaloids generally, the Atlantic rock is very
r^ular in its yield. This makes up for its poverty.
Arizona* produces large quantities of oxidised ores of coppw,
especially the oxide and carbonates, which occur in or adjacent to
the CarfooniferouB limestone. Sometimes there are irregular ore-
bodies at the contact of the limestone with granite or with sand-
stone. Masses of sulphuretted ores which have escaped decay
show whence the oxidised ores have been derived.
The Butte district, Montana,t has surprised the world of
late years b^ the enormous quantities of copper ore vhich
it has sent into the market. The deposits are east and west
lodes in granite, usually dipping steeply to the south. The
main lode, which supports the celebrated Anaconda and Farrott
mines, has proved productive for a distance of three miles along
the strike. The principal ores are erubescite, copper glance,
and chalcopyrite. Everywhere near the lodes the granite is soft
and friable, and often contains ore-bodies. Thoagb the granite
has been greatly fissured, it seems likely that much of the ore
does not fill up cracks, but has gradually taken the place of the
rock by a process of substitution. The width of the Lodes varies
Gonriderably ; however, on an average it may be taken at ten feet.
The copper ore k silver-bearing, the proportion varying from J oa.
per unit of copper to 3 oz. per unit.
The upper peirtu of the veins consisted of oxidised minerals, from
which the copper had been leached out almoet entirely, but in which
the silver was retained and formed the original object of the mining.
At the Anaoonda mine there was no copper worth speaking ot
for the first 400 feet in depth ; then came a rich zone of
<aisn]phides and erubescite, conradered to contain some of the
copper which had been dissolved out of the vein at a higher level,
and after lasting for 300 feet it was succeeded by the unaltered
solphidea.
Diamonda. — By far the most important diamond district in
the world is Kimberley, in Cape Colony, 64$ miles by rail from
Cape Town. Stiange to say, most of the predons gems are
* DoDglas, Op. cit.
t DodkIu. (V- '^- Vo^Qlaang, " UittbeUaDfcen Uber dan Enpferbe^
bso in Nord-Amerioa," ZtUtcir. £.- H.- u. S.-Wtten, vol. kz^. 1891,
p. Z31. O. TOm Bath, " Uebsr das Ganerevler yod Batte, Montana," N,
JaJirb./. Miner. Otol. u. l^aidont., vol L (1885), p. 158.
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38
ORE AND STONE-MINING.
obtained from four deposits situated in close pFoximily to each
other ; indeed, all four are included in a, circle three miles in
diameter. The massee of diamond- bearing rock may be described
as huge vertical columns, of round, oval, or kidney-shaped section,
as shown by Figs. 30 and 31.* The un weathered diamond-bearing
¥ia. 30.
Fig. 31.
Fock, locaUy known aa " blue ground," or " blue," is a breccia,
consisting of fragments of shale, basalt, diorite, and a little
sandstone, cemented together by olivine rock containing diamonds
and various other minerals, such as bronsite, biotite, talc,
garnet, graphite, magnetite, and iron
pyrites. The surrounding rocks, locally
called " reef," are beds of carbonaceous
and pyritiferouB shale lying horizontally,
and ^eets of basalt and melaphyre,
under which comes quartEite. The mela-
+ phyre is a hard amygdaloidal rock,
which has also been called olivine dia-
""'m^%S ''^M-'l" I^rge detached masses of the
^^ surrounding rocks are sometimes in-
" eluded in the "blue," and are then
known as "floating reef." The upper
parts of the deposits have been deoom-
poeed by atmospheric agencies, and changed into a soft friable
earth to a depth varying from 45 to 60 feet, and the colour is
yellow, instead of the slaty blue of the unweathered rock. The
surrounding rocks have naturally shared in this weathering.
* De Beers Consolidated Uioee, Limited, Second Annul Beport, 1890,
inclndiog a technical report with [ilates.
t Ibid. p. 13.
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MODE OF OCOUERENCE OF MINERALS. 39
The dianioiid'bearmg rock appears to be the fiUisg-up of the
necks or throats of old Tolcaaoes by a mud from below. Ftom
the fraqaent occuirence of broien diamonds it b fairljr inferred
that the gems were not formed in aitii, but were carried up
with the " blue."
Kot only does the yield in diamoadB vary in the different minee,
bat the diamonds themselves have their peculiar characteristics,
which enable the expert to say at once from which mine a stcme
has been obtained. The average yield. of the "blue ground"
per load of 16 cubic feet 'is as follows: —
An.
CnupdrbHd.
VtXatterant
Bnltfontem
DeBean .
Dn Toit's Pm .
KImberley
. ito
. . litoi .
In addition lo these four mines there are some other workings
in the naighboarhood, such as Wesselton and St. Augustine ;
ffhilKt at Jagersfontein, 80 miles to the south in the Oran^ Free
State, there is a similar deposit, producing stones of the finest
water.
The commercial importance of the diamond deposits cannot be
overestimated, for the value of the diamonds produced annually
at Kimberley is between three and four millions sterling, or more
than the value of the gold produced by any one of the British
coloniee.i'
Until lately, the largest diamond found weighed 428^ carats
in the rough state, and za8^ carats after cutting ; it came from
De Beers mine. This large stone has been eclipsed by one of 96^
carats discovered at Jagersfontein in the month of June last.
In addition to diamonds found in a solid matrix, there are
tiiose from the river diggings. It was in the recent alluvium
of the Vaal River that diamonds were first discovered in 1S67,
and though thrown into the shade by the output of the mines,
the gravel is still washed by parties of men scattered along the
banks of the river for a distance of 70 miles.
Diamonds aro found in alluvial gravel and in oonglomerate in
Brazil, India, and other localities.
Flint. — It may be thought strange by some that I give flint a
* Sixteen cnbie feet of broken ground, oomspond to about 9 ccblc test
of (oUd ground.
t Further informatfon aboat the Klmberle; diamond mlnM will befonod
in the foUowing poblicatlons :— T. BenneTt, " Diamond Mining at the
Cape," BUbny, Frodutdimt, and Retimret* o/the Cajae of Good Hope. Cape
To«n, 1SS6. C. Le Kare Foiter, "Uioing Induatries," Srportt on ttta
Cntonial and Indian £xA&ilion. London, 1S87. E, Bontan, " Bnr I'etat
aetnel dee mines de dlamantit dn C^," Oiaie dml. Paris, Jannaij 36,
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40 ORB AND STONE-MINING.
place among the important minerals which deserve specia] de-
scription. My reasone for mentioning it are twofold. First, the
Si/i WkiU Chatk
Hard mtlu^Ck^M '.
UUtrCn^i Flint .
.1^ Wliiu CkalM
Sfctml Piftclaf .
Hard Chalk
earliest nnderground workinge in this country were probably for
flint; and secondly, flint affords a good instance of the replace-
ment of an original bed by another mineral.
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MODE OF OCCURRENCE OF MINERALS. 41
Fits in the chalk known as " Gnme's graves,"* were at one
time a puzzle to the antiquary, bnt it is now generally conceded
that they are the mine shafts by which beds of flints were worked
for the manufacture of stone implements in Neolithic times.
This old trade of flint mining still survives at Brandon in
Snfiblk, for though stone hatchets and arrow-heads are no longer
wanted, there is still a market for guu-flints in parts of Africa. The
mode of mining the stone, splitting off flakes and knapping them
into gun-flints has been admirably described and illustrated by
Mr. Skertchlyt in one of the " Memoirs of the Geological Survey
of Gngland and Wales." Fig. 31 represents a section of the beds
in which the flint occurs. It shows that the layers of flint are
aometimee continuous, and eometimee consist merely of a euoceasion
of nodules which do not touch each other. Some of the flint has
knobs and even horn-like projections, the transformation from
chalk into silica not being confined strictly to one particular layer
of the original sea-bottom. The principal bed is the " floor-stone,"
No. 20, about 8 inchee thick, hut other layers are mined from
time to time for building stone or gun-flinte.*
Freestone. — ^Freestone is largely quarried in England from
beds of Jurassic age, and the so-called " Bath stone" is not only
quarried but also mined at Corsham in Somersetehire, and at
Weldon in Northamptonshire. The bed worked in the Corsham
anderground quarries varies from 8 to 24 feet in thickness, lying
almost flat ; it is a typical oolitic limestone which can be sawn
freely in any direction. §
Qold. — This metal is so widely distributed over the earth that
it will be impossible to compress into the space at my disposal
anything more than a very summaiy description of the principal
modes of occurrence in beds, veins, and masses.
jBw&.^During the last few years the attention of cap-
italists, miners, and geologists has been often directed to the
marvellous resources of the WitwatersrandU or simply " Baud "
goldfleld, in the Transvaal or South African Republic, and
situated about 35 miles south of Pretoria, the capital. The gold
is obtained entirely from beds of conglomerate or puddingetone
called banket, which is the Dutch name for almond rock, the
hardbake of the British schoolboy, because the pebbles look like
* Th« word " grave " no donbt corresponds here to the Gttnnui Oraben,
a ditch or trench, and haa no reference to bnrial.
i On lie Maan/ariurr of Oun-Flinti, &C. London. 1879.
+ A more or leis [egalor aii<i contlnnani layerot llinti it locallj called a
Mue or tie, which reoalls the French word " assUe."
S C. Le Neve Foeter, " Same Mining 'Soias In 1887," Tram. Mia. Atioe.
ar^ Itut. Cornuxdi, voL ii. p. 136. Camborne, 188S.
II A veiT complete scmmarj of papers npon South African Geology 1*
idvea b; Mr. Gibson in bis memoir, "TheOeoloKyof the Qold-bearing and
kmmnfAmt^ llAnVa nf tliA RAnthffrvt TrnnHVBBi " Otuirt. JniLT. f?rtn/. Sne..
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ORE AND STONE-MINING.
the almonds in the sugar. The
^vQ layers of auriferous conglomerate
^^ I lie conformably among beds of
e^v^S sandstone, shale, clay, amtquartzite.
^^'I* At Johannesburg the beds strike
g S S east and west and dip to the south.
•~^^S The conglomerate consists mainly
^ " I of pebbles of white quarti, and in
1 5 "_j3- the upper parte of the workings
J -tla theyarecemented together by oxide
I'cf £ S of iron, sand, and clay. Below the
^j».B influeneo of atmospheric agencies,
^ B Q S the cementing material ib found to
clt „ £ consist largely of silvery-grey mi-
a—^Z caceoiis matter with cubical crystals
-osJ.^ of iron pyritee, and the colour of
^ E<a g the banket changes from red and
oj'^9 brown to blue and bluish grey. It
^1>^ u is quite evident from the ezamiiut'
■§ 8^'& tion of specimens that much of the
0 |<H'p ferruginous matter in the upper
2 -S ^ J parts of the conglomerate is derived
■cl c^- from the decomposition of iron
,3 i' pyrites, and visible gold is seen in
.* ^."S the cavities formerly occupied by
■g B 5 M crystals of that mineral. The bulk
^-^ iS of the gold is said to exist in the
■■°tJ " cement and not in the pebbles; but
1 o S**! some assays made by the late Mr.
** S 8 — Richard Smith show that this is not
^1 1 ~ invariably the case.
•S i 5^8 Fig. 33,* a section across the
° "xi Salisbury Mine at Johannesburg,
c I ^ a shows four beds of auriferous con-
's Sl^M glomerate, known respectively as
"S E *:r the North Roef.tbe Main Reef.the
^ £ p k Main Reef Leader, and the South
-^■Z^^ Reef.
8^§"i, As would naturally be expected
I § £ 8 'Q the case of beds which must have
§«&"« been deposited in shallow water,
""^ * a _*i there are frequent variations of
K'«"5i^ character and thickness In a short
« i' o ? distance,
■oj-g** Whilst certain beds of conglome-
£ n^ (^ rate are auriferous, others are not,
""-If
- B 5> • Gibson, /iiW. p. 411.
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MODE. OF OCCURRENCE OF MINERALS. 43
or contain merdy traces of gold. The sandstone, as a rule, is
not auriferous, but layers within the banket may be worth
working. The richest beds are the Main and South Beef with
some of the thin " leaders." The gold is not distpibated
uniformly through the bed of banket ; but upon the whole there
ib far greater regularity of yield than can be expected in a. vein,
and ae a rule the whole of the bed is worked away like a seam of
■xml, without poor portions being left. The fact of being able to
form a rough approximate estimate of the probable yield of a
given area of banket is of the utmost commercial importance.
The Band output in 1893* was 1,2 10,865 ounces of bar gold ;
the average total yield of the conglomerate stamped was 13^ dwt.
of gold per ton, of which about four-fifths were obtained at once
by amalgamation at the mills, and one-fifth by subsequent treat-
ment of the tailings and concentrates.
The gold-bearing strata are supposed to be of Devonian age.
Whether the gold was deposited at the same time as the
pebbles of quai-lz, or whether it was brought by the sabsequent
I highly anriferoOB in 1 , .
beoomiug aq^iUaceons in places ; d, impore Mndstone qoarttite,
C qnartiooe breccia wiih fragmentg of teUite and clay shale ; f,
hard grey siliceons shale ; g, highly anHferons sandy matter
resnlt^g from the disintegration of the bed b.
infiltration of mineral solutions which found their easiest
channels of escape through the most readily permeable beds, has
not been decided; but where the bulk of a deposit consists of
■ FhllUps, " AddiMi to the Band Chamber of Hlnea," Jannaiy afitb
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44 ORE AND STONE-MINING.
materiale of undoubted eedimentary origin, it is beet for the
miner to call it & " bed " or " seam," and leave the question of
origin to be settled later on by the geologist.
Fig. 34 repreaenU a section of the Sheba mine, Barberton,*
where the gold is obtained from & bed of auriferouB quaitsite.
Fig. 35 is a section of an auriferous alluvium in tiie Garatal
district of Yenezuela.f
Fia. 35.
The following is the sDOMs&ion of the beds:—!. Soil. 3. Red
ola;, Bfaowiog do aigns of stratification. 3. Soft clajey " moco de
hleno." 4. Hard brown iron ore ("moco de bierro"), with
piecci of qnartz in it and a, litlle cla;. 5. Blocks of veln-qnartE,
often anriferona. 6. "Greda," or pay-dirt, a yellow ferroginoas
clay coataloing naggets and small grains of gold. 7. " Cascajo,"
decomposed achist, forming the " bed-rock."
Fig. 36 explains how a superficial gold-bearing "rainwasb"
may result from the denudation of a bed of auriferous gravel.
.Some of the deposits of gold in Brazil occur under totally
different conditions. The precious metal is found in beds oi
jacotinga, the local name for a friable mixture of micaceous iton,
earthy brown iron ore, oxide of manganese, lithomarge or talc, a
little quartz, and small lumps and granules of gold. The beds of
jacotinga occur as subordinate bcuids in the rock known as
itabirite, composed mainly of micaceous iron, specular iron, mag-
* MS. of C. J. Alford, F.G.8.
+ C. Le NeTe Fonter, " On the Cuatol Gold-field," ^iiorf. Jour. Otol.
Soe , voL XXV. 1S69, p. 340.*
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MODE OF OCCURRENCE OF MINERALS.
I. Schut ("CsAcajo ") or felatone forming the bed-rock of afer-
mginons gold -bearing gravel ("moco de bterro") a ; 3. Ked fer-
rngiiioui earth (" Tiena de &01 '') coDtsiDinf; nnggeta of gold.
Though the jacotinga forms bede, the gold is not unifonnly di»-
triboted through it, but U concentrated in productive ehootp
Taiiu. — The veins usually consist in great part of quartl, and
contain in addition iron pyritee, or some other heavy metalhc sul-
phidee, such as galena, zinc blende, copper pyrites, magnetic pyrites,
stibnite and miepickel. The gold is principally iu the metallic
state, even when enveloped in pyrites, which is so frequently the
case; but it occure tCtao in combination witft tellurium, and with
bismuth .
The "Great Quartz Vein," tar "Mother Lode^" in the Sierra
Nevada of California is the first deposit that must be noticed;
for it is remarkable by its length, its width, the number of
mines which are dependent upon it, and their annual yield of
the precdouB metal. Some of the moat important facts concerning
it ha,ve been described by Whitney.* The axis of the Sierra
Nevada is a mass of intrusive granite, which is flanked by meta-
morpfaic Triassic and Juraesic rocks ; the existence of fossils proves
the gold-bearing strata to be uf Secondary age. The rocks in
which the principal gold veins of this region occur, are slates
of various kinds, such as clay-slate, taloose slste;atid chloritio
slate, which form a marked belt, sometimee i S mike wide, running
through the country for fully 150 miles. The slates' ate accom-
panied by a band of serpentine sometimes . a; mile wide. " Aeso-
ciated with the serpentine is the very remarkable mass of quartz
known as the ' Great Quartz Vein,' which may be traced for a
distance of 80 mile« from Amador County to Mariposa County in
ageneral S.E. by S. direction."t "This powerful lode is'made
up of irregularly parallel plates of white compact quartz and
CTystalline dolomite or magnesite.t more or less mixed with
• The Avr^erout GracfU of tht Sierra Kttada nf Catlfornia. Cunbrtdge,
U.S., iSSo, p. 45.
t Cto. «(. p. ^.
t Whilnei; adds tbe note — " In tbe onlj apeolmeB which baa thni tvt
bMB obemically eiamiiied, the suppoied dolomttic portion proved to be
an Inthnate mixture of quartz and msgaealte."
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46 ORE AND STONE-MIKING.
green talc ; and these plates, which somewhat reeemhle the
' combs ' of ordinary lodes, are either in contact or aepar&ted frran
each other by interaalated layers of taJcose slate." "The qtiarts
is the auriferous portion of the lode, although it ie far from bang
uniformly impregnated with gold." " The talcose slate bands in
the vein are often themselves more or less auriferous." In one
place the vein is 261 feet wide measured horizontally across it,
and it dips to tlte north-east at an angle of 60°. Whitney says
it is not proved to be a fissure vein, and he is more inclined to
consider it as a metamorphosed belt of rock.
The map of the lode given by Collins,' shows seventy-seven
mines which are now being worked, or which have been profitably
worked in recent times, and we leam from him that the auri-
ferous quartz contains small quantities of metallic sulphides, such
as iron pjrrites, mispickel, marcasite, chalcopyrite, and galoia.
The quantity of gold produced from the quartz treated varies from
3 dwta. to 1 5 or 20 dwta. per ton, and the " Great Quartz Tain "
or " Mother Lode " is estimated to yield about two million dcdlars
worth of gold annually.
The gold veins, or " reefs," in Victoria are found in the tipper
and Lower Silurian ropks. The gold is especially a^ociated with
Via. 37.
iron pyrites ; when it decomposes a cellular honeycombed quarts
is left behind, and the gold is unmasked and rendered visible
in the little rusty cavities. Other heavy metallic sulphides are
common here as elsewhere.
The peculiarities of the so-called "saddle-reefs" of l^e Sand-
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MODE OF OCCURRENCE OF MINERALS. 47
hurst or Beadigo gold-field, Victoria, which differ considerably
from typical vema, have been very clearly explained by Mr. T.
A. Rickkrd,* from whoee uaeful memoir the following account is
borrowed. Tbeee reefs are arch-like masses of quarts conform-
able to the bedding of the surrounding Lower Silurian slate and
sandstone, as shown by the letters BACin Fig. 37. The part
A is called the " cap" or " apex"; B is the " west 1^" and C the
" east leg," because the main anticlinal axes strike K.N.W. and
S.S.E. The part D ia known tis the " centre country," the rooks
to the east of C form the " east country," and those to the west
of B the "west country." The inclination of the line of the
ridge, northwards or southwards, is
spoken of as the " pitch," in order to ^i<^- 3^-
distinguish it from the dip of the ■
strata. There may be more than one
such saddle, or a long succession of
them, one below the other (Fig. 38),
but they are not all equally auriferous.
Tous, out of five which have been
discovered and explored at " 180"
mine, only three have proved to be
worth working for gold.
Similar masses of auriferous quarts
have been found at some of the
synclines ("inverted saddles"), and
worked to a slight extent. Very
large dividends mtve been paid l^
many of the companies worlong tlie
"saddle-reefs."
if asses. — Having given examples
of auriferous beds and veins, I come
to masses. Treadwell mine,t situated SADDLES
on Douglas island, Alnska, owes its
existenoe to a mass of auriferous altered granite, 400 feet wide
and of considerable length. The rock, which appears to have
been a hornblende granite originally, now consists principally of
quarts and felspar, with a little calcite and specks of iron pyrites,
and it is traversed \>y strings of quartz, iron pyrites, and calcite.
The original rock was probably crushed and fissured, and then
brought under the action of solutions which penetrated into it
in all directions, and so produced the alteration. The yield is
considerably less than ^ oz. per ton, but as the deposit can be
• " The Bttidlgo Ocld-Field," TVaja. Amer. Intt. M.E., vol. xx. (1891),
P 463-
T 6. U. DawsoD, " Notes on the Ore-deport of the Treadwell Mine,
Aluka," Amerkan Geohgitt, 1889, p. 84 ; and Frank D. Adamv, " On the
HknMcopioal Charaoter ol the Ore of Ihe Treadwell Ulna, Alaska," Jbid.
p. 88.
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48 ORE AND STONE-MINING.
worked opeacaat, the coet of getting is low. Much of th« gold is
free, and can be extracted by amalgamation in spite of its being
enveloped by pyrites.
Thifl mass may be called a stockwork or net-work deposit.
The productive Mount Morgan mine,* near Hockhampton, in
Queensland, wbile astonishing the world by its ricbness, afibrds a
puzzle to geologista which has not yet been satisfactorily solved.
The auriferous deposit, which is worked aa an open quarry, is a
mass of brown bsniatite, sometimes stalactitic and containing a
little silica, which passes gradually into a ferruginous ailiceoiis
sinter. S<nDe of it is spongy and frothy in appetirance, and bo
full of cavities that it will float upon water like pumioe. The
precise nature of the gold-bearing mass is well illustrated by
twenty views which accompany the '"ttird Report" of Mr.
R. L. Jack, the Government geologist.
Both the sioter and the brown iron ore contain gold, and
yi«ld on assay several ounces to the ton. The auriferous stone
Fio. 39.
caps a hill rising about 500 feet above the neighbouring table-
land, and the most important part of it is the actual top or crown,
an oval mass 300 yards long by 170 yards wide.
Mr. Jack considers that the deposit is the product of a geyser,
and he explains his views by the section (Fig. 39). This naturaUy
represents the present condition of the bill, much of the <niginBl
geyser deposit being supposed to have been removed t^ i^nu-
dation.
The gold exists in a state of great fineness, and the metal
extracted is of extreme purity, for it oontaiiu 997 of gold,
the rest being copper, a trace of iron, and a minute trace of
silver. Dr. Leibius, of the Sydney Mint, speaks of it u the
richest native gold hitherto found.
Without having examined the deposit upon the spot, one
scarcely likes to criticise the conclusions of so able an observer
aa Mr. Jack ; but looking at his section of the No. i tunnel,
we find that the auriferous mass must repose upon highly
Eyritous rooks, such as quartzite full of fine pyrites, in which the
ttter constituent may sometimes predominate. The suspicion
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MODE OF OOCURKENCE OF MINERAXS. 49
naturally croeaes one's mind tliat the gold-bearing cap may simply
be due to the decomposition and weathering of the pyritiferoufi
rock. Mr. Jack combats this theory, and eays that it is dis-
proved by three facts : ist. A dyke of dolerite in the quartzite
does not reach up into the overlying sinter. 2nd. The pyri-
tiferous quartzit« is poor in gold. 3rd. The silica of the sinter is
hydrated. He tbereEore still maintains his original opinioD that
the tdutar and irouatone were deposited by a thermal spring on
the pyritous qaartzite, and are not altered portions of it.*
Mr. Kiokardjt while disagreeing with the geyser theory,
concurs in Mr. Jack's opinion that the deposit is not an altered
portion of the pyritous quartzite, though he remarks that the
FiQ. 40.
Mount Morgan rock bears a strong outward resemblance to the
decomposed outcrop of the Broken Hill lode in New South Wales.
This can be easily imagined from an inspection of the views given
in Mr. Jack's third report, from which the outlines of Fig. 40
have been copied, ^e theory propounded by Mr. Rickard
{F^. 41) is that the auriferous stone of Mount Morgan is rock
shattered by the intrusion of dykes, and then altered by the per-
colatitm of underground mineral solutions, which found an easy
pasmge through the cracked and fissured mass. He points out
that the gold may have been derived from the poor pyrites
disseminated through the quartzite, or from the sandstone of the
district, which has been shown to be auriferous.
The quantity of stone treated by chlorination at Mount Morgan
* Second Beport, p. 4.
t " HoDnt Morgan Hi&e, Qaeensland," Tram. Amer. Itut, M.E. vol. xx.
<i89i),p. 133-
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5° ORE AND STONE-MINING.
in the twelve months ended 30th November, 1889, was 75,415
tons, from which 313,542 oz. of gold were obtained, equal to
4 OE. 6 dwt. per ton. The gold waa sold for ^^11331,484, and
jf^i, 100,000 was p&id in dividends.
Grsphita.— The great graphite mines of the world are those
of Ceylon, where the mineral is found in layers from a few inches
to several feet in width, in gneissand mica schist. The graphite
is associated with quartz and a little iron pyiitee.
There are various graphite deposits in Austria and Bavaria.*
At Kaiserberg, in Styria, the mineral is found in graphitic schist ;
the beds vaiy in thickness very rapidly from a few inches to 20 feet.
Iq Lower Austria, Moravia, Bohemia, and Bavaria graphite
occurs in gneiss usually accompanied by gmnular limestone. The
Passan gr^hite is in the form of small black scales, and appears
to take the place of some of the mica in a highly felspatbic gneiss ;
the thickness of the beds varies greatly, but may be as much as
16 feet {5 m).
The Bavarian mines produced 3352 tons of graphite in 1888.
aypsam. — As one of the principal uses of gypsum is toe
making plaster-of-paris, we naturally turn to the French
metropolis for an example of the mode of occurrence of this
mineraJ. The gypsum is found in beds from 50 to 60 feet thick,
which are of Upper Eocene age (Fig. 352).
In England and elsewhere, the Tnassio rocks have long been
remaricable for containing valuable beds of gypsum, and they are
largely worked in Derbyshire and Nottinghamshire. Fig. 43 re-
praeents the layers of nodules in a gypsum mine at Kingston-on-
Soar, Nottinghamshire. There are tlu«e beds a few feet apart in
the New Red Marl. The bottom bed consiste of large spheroidal
masses, varying from 5 to 8 feet in thickness, and 5 to 10 feet in
diameter ; above it are two layers of " balls " and nodules, more
or less continuous. The highly gypsiferous marl, locally called
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MODE OF OCCURRENCE OF MINERALS. 51
" fault," B, between the big balls, A A, is left, so as to form pillars,
which sapport the roof of the worbdngs.
White translucent alabaster for statuary purposes is mined at
Castellina Marittima," in the province of Pisa. Its mode of
ocGOTTence reeemblea that just de-
scribed, for it is found in irregular Fig. 42.
spheroidal or kidney-shaped masses
called "ovuli" by the workmen, from
a few inches to several feet in dia-
meter, and occasionally weighing
more than a ton each. The grey
marl sturounding the nodules is of
Pliocene age. l^e alabasier is sac-
charcndal and very fine grained.
loe. — Bysome persons thisminerel
may be considered beneath notice, but
the trade in ice is so large that it
deserves at least a passing mention.
The United Statee t are the largest
producers of natural ice in the world,
and in some years 12,000,000 tons are gathered from the lakes
and rivers, and especially from the Hudson. The gathering in of
the ice crop a&brds employment to " 12,000 men and boys, 1,000
horses, and 100 steam engines." Much ice is exported from
Boston, and Norway also is a country with a large ice trade.
Inm.— This metal is very widely distributed over the globe,
and affords examples of many modes of occurrence, though veins
of iron ore are quite driven into the background by the jrleld of
beds, and especially those of the Jurassic age.
The most productive European deposits at the present lime
are ; the bed of iron ore in the Cleveland district, the masses of
red luematite in Cumberland and North IJancashire, the bed of
brown hematite in German and French Lorraine, and Luxem-
burg, and the beds of red and .brown hiematite near Bilbao, in
Northern Spain.
The bed of ironstone worked in the Cleveland district of North
Yorkshire is found in the Middle Lias. Mr. Kendall % gives the
foUowing general section of the rocks : —
X "The Inm Ores of the EDgllah SeooDdarj BockB," TVotw. AT. ofS*g.
' . m^„ . __. ,_■,=„ _ ._. Bajfo^^ "The Oeology of North
.vGoogli.^
OHB AND STONE-MIKINO.
r.-«ip.i«.
Wrt.
Sbala with o«nent tout
I'rmm- nixlnle. (alniD Bbale Mrie*)
£Sf SUte with doggwB- (irt rock
A. oommiuiU ,
A. SMpentlniu
300
A. fttmnUtnl '
IroDitone (Haln mud) .
ShiOe with dOEK«n
Vol \^'Pi^tnB
Slikla with oodolM of cl»7
Um
diwgsn ....
yyo
■
400
A. oapriooniaa, Jk- '
^ lto<-tone8 in th- lowe«
meaonl, anutns, i
oxTHOtn*, Bnck-
7000
^phu^t^
Fig. 43t illustrates sections of the bed at £ston and TJpleatham.
Fio. 43.
Satan- fftUaihant.
Gnji ikalt aitJ/tmitiiuus tudulit
Iromlaiu Imalnbltci), vvrkaili furl e/ hd \ f9V}'
V (JSfMH jte:() •»/ «V>-;(I
The Main Seam practically fumisheB all the Cleveland ore. It
probably extends over an area of 350 square miles, though it
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MODE OF OCCURRENCE OF MINERAI^. 53
cannot be profitably worked over aQTthing like the whole of this
district. The avera^ thickness where worked ie about 10 feet. -
The beds dip very gently about i in 1 5, to the BOuth-ea«t. The
Beam is thickest and best at Normauby, Eston, and Upleatham ;
in proceeding to the south-east, partings of shale appear, and
split ap the main seam into nameroua comparatively thin layers
of ironstone, with a smaller perceDtage of metal. Some of the
ironstone is oolitic and of a greenish grey coloar, but much of it
is not oolitic, and is bluish grey in colour, resembling a mudstone.
The iron exists chiefly as carbonate, some of which, aocording to
Dr. Sorby, was deposited mechanic^y, whilst the rest was formed
chemically by replacement of carbonate of lime. Afi a general
average, it may be said that the ore contains 30 per cent, of
irtm. The district produced 5,138,303 tons of ore in 1891.
The masses of red hsematite worked in Onmberland and Korth
I^ncashire have already been noticed (Fig. 14).
The groat iron-field of Lorraine,* much of which became the
property of Qermany in 1S71 after the Franco-Prussian war,
stretches ont from Nancy post Metz and Diedenhofen into
Luxemburg. It may be called 60 miles long by 10 to 12 miles
wide (100 km. by 15 to 30 km.).
The iron-bearing strata belong to the Lower Dogger or Brown
Jura (Inferior OoUte), and consist of marly sandstone, marl and
sandy clay, interstratified with beds of limestone and iron ore.
In places there is no iron, and in othere, especially in the south
and on the eastern edge, the beds of ore are thin. On the other
hand, at Esch, in Luxemburg, four beds of iron ore and their
partings of limestone and sandstone make up a total thickness of
65 feet (30 m.), and at Deutsch-Och and Oettingen three beds and
the partings are 32 feet (10 m.) thick; then at Hayingen the total
thit^ness sinks to ao feet (6 m.), and at Ars there is only one bed
5 to 6 feet thick. The strata are slightly undulating, but the
general dip is i to s^ in a hundred to the south-west. The iron
eziBts in the state of hydrated ozid^ probably for the most part
ss 3FejO,3HjO, which constitutes the roe-like grains which are so
characteristic of the ore.
The oolitic particles are enclosed in a calcareous matrix, which
may contain quartz. The matrix is always more or less ferru-
ginous, and sometimes consists of a greenish mineral, which is
probably a silicate of iron. The ore has usually from 33 to 38
par cent, of iron and from ^ to 2 per cent, of phcsphorus ; there is
also a little sulphur, due to occasional small strings of iron
PTritee. The name " minette," or " little, unimportant ore," was
given many years ago to this bed in contradistinction to the
' Wuidesleben, " Das Torkommen der ooUthisohen Biiena^e (Uinatte)
in Lotbrlagui, Loxembui^ and dam MUicben Frankrelob." Der IV, AJi-
ofTxcim DtuUtAt Btrgmanmlag tn Hidit (SaaU). Fatbeneht tmd Vtr-
luaidbaigtii. Halle, 1890, p. 297.
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54 ORE AMD STONE-MINING.
" mioe " or " minBrai de fer fort," a much ri<iher ore found in the
neifhboorhood, which is now no longer worked.
Nearly a hundred blaet furnaces are dependent upon the
" minette " for their Buppliee of ore, and in 1888 they produced
2,500,000 tons of pig iron, or 40 per cent, of the total pn>duction
of Germany, Luxemburg, and Fiance. More than four-fifths of
all the iron ore raised in this last country is obtained from this
bed. The amount of ore still available in German Lorraine is
estimated at 2,100 million tons, or enough to maintain the pre-
sent rate of production for 750 years.
Sweden is justly famous for ite great deposits of magnetite.
These are generally lenticular masses, often similar in shape to
the Bio Tinto copper veins, and enclosed by highly metamorpboeed
rocks, such as gneiss, mtca schist, and tbe hard compact kdUefiinta
of the Swedish geologists.
It would not be right to quit the subject of iron ore without
mentiomng at least one of the mines situated in the neighbour-
hood of I^e Superior, where tbe Menominee, Gogebic, Vermilion
and Mesabi districts are producing large quantities of mineral.
At Cbapin Mine* near tbe town of Iron Mountain (Mich.)
there are huge lenticular massea of haematite, which lie parallel
to the enclosing Huronian strata {Fig. 44).t One large lens is
Fio. 44-
half a mile long, 130 feet wide in the middle, and gradually
tapering out to a point at each end ; it strikes 1 5° N. of W., and
dips from 70" to 80° N., and the axis of the lens pitches 30° W.
The ore contains about 63 percent, of metallic iron, and only
0-07 per cent, of phosphorus.
• LanaoD, "Tha Chapin Iron-minb, Lake Saperior," Tra»t. Aiuer. Iittt.
M.E.jol. XTl. (1887), p. 119.
+ Engiaeerlag, \oL L (1890}, p. 55a.
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MODE OF OCCURRENCE OF MINERAIA
SS
I«ad. — Though lend ore is l&rgely wrought from veins, one of
the great mines in the world obtains its supplies from a bod. The
lead-bearing sandstone at Mechemich, in Rhenish Prussia,* is of
Triasedc age (Bunter) and is on an average nearly loo feet thick.
It rests npon and is covered by conglomerate, and is often split up
into two or mere beds by thick partings of conglomerate. Tbe
ore exists in the form of little concretions of galena and grains of
qaartz, but these are not uniformly distributed through the sand-
stone. The concretions are from ^'j^ inch (i mm.) to | inch (3 mm.)
Pio. 45-
s«a*t
^
A, gnj^rscke ; B, conglomerate ; C, lend-besrlng sandstone ;
D, coDgiomerato ; B, la^OBlled "red Tooka," condsttnK of red,
jiSam, and white sandstone, with variegated shales and ulaj.
in diametor, and are harder than the surrounding sandstone,
which is generally very friable. When the rock is pulverised
the little ^ot-like masses remain, and are called "knota''(Jrnoa«n),
wh«ice the name " Knottensandstein " given to the bed. Toe
■mount of metallic lead in the sandstone is between 2 and
3 per oent. ; but the concretions themselves contain from 20 to 34
per cent. According to the statement of accounts presented to
the aharebolders,t the average percentage of lead contained in
tbe whole of the sandstone treated in 1890 was 2'3i8; 347,706
cubic metres (454,806 cubic yards) of sandstone, were raised from
tiie mine and open work, and yielded 36,245 tons of lead ore for
•mehang and 733 tons of potter's ore. This would be at the rate
of 1 04)01. of dt«wed ore per cubic metre, ori J cwt. per cubic yard,
but it must not be fMgottec that the bulk of the ore — i.t., that
which goes to the furnaces — is not highly concentrated and con-
tuns only 54 per cent, of metal. The proportion of silver in it is
5I ounces (180 grammes) per metric ton.
The hi^ory of Leadville, in Colorado, seems like a romanoe
whan wfl read of the rapid development of the mines, the creation
of a large and important town, Uie erection of smelting works
■nd the building of railways, under very adverse conditions, in
• BtT Btrgbaa vitd HOttethttTUh det HechtnUcheT Bergaerlct-ActUn-
Yenitu. Cologne, 1SS6.
t Mining Journal, vol. bcL (1891), p. 499.
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ORE AND STONE-MINING.
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MODE OF OCCUERENCE OF MINERALS. 57
the heart of the Rocky Mountains, all within the space af four or
fire jrears. It aflbrds additional proof that the miner is the true
pioneer of ciriJiBatioD. The L^rille deposits hare been ad-
Doirably described by Mr. S. F. EmmonB,* from whose exhanstiTe
report I borrow, not only the following facte, but also a section
across one of the mines (Fig. 46).
The principal deposits of the r«^on ore found at or near the
juuction of white porphyiy with the underlying Blue Limestone,
which is the lowest member of the Carboniferous formation.
This bed is about 1 50 or zoo feet thick, and consists of dark-blue
dolomitic limestone. At the top there are concretions of black
chert. The porphyry occurs in intrusive sheets, which generally
follow the bedding, and almost invariably a white porphyry is
found overlying the Blue Limestone. This porphyry is of
Secondary age. It is a white homogeneous-looking rock, com-
posed of quartz and felspar of even granular texture, in which the
porphyritic ingredients, which are accidental rather than essen-
tial, are small rectangular cr^'stals of white felspar, occasional
double pyramids of quartz, and hexagonal plates of biotite or
black mica. Along the plane of contact with the porphyry the
limestone has been transformed, by a process of gradual replace-
ment, into a so-called " vein " consisting of argentiferous galena,
ceruasite, and kerargyrite, mixed with the hydrous oxides of iron
and manganese, chert, granular cavernous quartz, clay, heavy spar,
and " Chinese talc," a silicate and sulphate of alumina. The vein
seems to have been formed by aqueous solutions, which took up
their mineral contents from the neighbouring eruptive rocks, and
brought about the alteration of the limestone as they percolated
downwards through it. In Carbonate Hill a gradual passage may
be observed from dolomite into earthy oxides of iron and manga-
nese. The masses of workable ore are extremely irregular in
shape, size, and distribution. They are often from 30 to 40 feet,
thick vertically, and occasionally 3o feet, but only over a small
area. The rich ore bodies are commonest in the upper part of
the ore-bearing stratum. At Fryer Hill the Blue Limestone is
almost entirely replaced by vein material. The metallic ores
appear to have been deposited originally as sulphides ; the oxidised
or chloridised ores found near the surface are the products formed
by the percolation of surface water like any ordinary gozzan.
Hanganese. — The great manganese-producing countries of the
present day are Russia t and Chili, and in both the ore is derived
from beds, and not from veins or masses. At Tschiatoura in the
Caucasus, about thirty miles from Kwirilly station on the Foti-
Tiflis Railway, there are beds of manganese ore of Miocene age.
The beds worked are from 5 to 6 feet thick (i'5 m. to 2 m.), and
• Otology and Mining Indi'rtni /•/ lAodviiU, Colorado. WashingtOD,
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S8 OEE AND STONE-MINING.
are made up of several email seams of clean manganese ore,
eeporatod hj partings of soft sandstone and clay. The manganera
exists principally in the form of MnO,, and the ore coutains
50 to 55 per cent, of metal. The mines are at present heavily
handicapped by the long and expensive carriage to Kwirilly
station, but this will be reduced when a railway is made.
Both in Wales and Belgium there are beds of manganese ore in
the Cambrian rocks. The Webh beds are about a foot thick (Fig-
47),BoroetimeBrunDiDgup to
1 8 inches or 2 feet. The man-
ganese is principally in the
form <£ carbonate, thongh
there is a little dlicate^ and
near the surface these have
been converted into hydrous
oxides. The on is inter-
bedded with fine - grained
sandstone, hard mudstone,
and shale, also manganiftir-
and often containing
chlorite, iron pyrites, and
magnetite; the whole man-
ganiferous series is enclosed
in the regular Cambrian gritx
and conglomerates. The ore
_ _ „ ^^KmiTti contains from 20 to 32 per
A. fine-giainedsandirtonewithmag- cent, mwiganese^
netite, chlorit*, and iron pyrites ; B, Marble. — The famous
maoganeM oie; C, fine-gTBlned sbaly white statuary marble of
"andfltone. Italy is found in the Apuan
Alps from Carrara to Stax-
zema, on the 8.W. slope of the ncuntains, and from Fivizzanoto
Vaglj Sotto on the N.E. slope.* It occurs in very thick beds,
with the stratification sometimes well defined, but generally
completely obliterated, and it rests upon compact limestone, whic^
in its turn lies upon pre-palKozoic mica-schist and talc-schist.
The age of the marble beds has not been ascertained without
doubt; some geologists say they nre Triassic, whilst Jervis calls
them pre-palseoEoic.
Mioa. — This mineral is obtained in North Carolina at the
present time, just as it was in the days of the prehistoric mound
builders, from veins of giant granite, or granite in which the con-
stituent minerals have crystallised on a huge scale. According to
Phillips,! a single block of mica has weighed nearly a ton, and
Pio. 47.
T=^^"--. ..-T^-^-.^
■'■^^i-H^t^i^^.^ A
^
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MODE OF OCCUEBENCE OP MINERALS. 59
pieces 6 feetlongand 3 feet wide Are sometimes met with; a single
cryBtal of felspar weighing 800 lb. is preserved in the State
Museum at Raleigh. The veins are from 30 to 40 feet wide, and
are enclosed in mica schist, of which they follow the strike and
dip ; but they occupy fissares which took place along plajies of
easy fracture, and being of subsequent origin to the surrounding
rocks, are veins and not beds.
Katnrsl OS8.* — Though the Chinese were before the Ameri-
cana in their use of natural gas, it is to the United States that we
moat look for examples of gas springs, which have been so largely
turned to account during the last ten years, more especially in
Fennsylvania, but also in Ohio and New york.
According to the late Mr. Ashbumer,! the gas in these States
comes from beds of Falieozoic sandstone and limestone. He
considars, with many others, that both gas and petroleum
have been formed by the decomposition of animal and vegetable
remains in the rocks, and that in order to have a productive gas
region, it is necessary that there should be a porous or cavernous
rock to contain the gas, and an impermeable covering, such as
shale, to prevent its escape, conditions resembling those required
for artesian wells. A further condition is that the strata should
be bent into a dome, anticUnal or arch, at the crown of which
the gas will be found ; but if the rocks have been much disturbed,
contorted, and fissured, natural vents have been formed, through
which the gas will have escaped. The rocks now containing the
gas are often those in which it was generated.
There are several gas-producing beds of sandstone in Pennsyl-
vania, in the Carboniferous rocks ; but the most important supplies
are obtunodfrom sands of the Venango- Butler oil-group, belong-
ing to the Oatskill Rocks of the Devtmian period. There are
other gas-sands in the Chemung and Portage rocks, also of the
Devonian Period, but lower down. Some of them produoe both
gas and oil.
The most productive gas-bearing rocks in Ohio are the Berea
grit in the Sub -carboniferous period, and the Trenton Xiimestone
in the Lower Silurian period.
The section (Fig. 48),} shows the Silurian and Devonian strata
bent into an arch or dome at Findlay, Ohio, where gas and petro-
leum are obtained by boring into the Trenton Limestone, the
reservoir in which they are confined by the Utica Shale,
The gas varies in composition, not only from well to well, but
also from time to time in the same well. Some analyses given by
Prof. Lesley show that the gas of a certain well contained npon
* Topley, " The Sources of Fetrolenm and NatonJ Oss," Jour. Sac ArU,
voLzxzix. (iSgi], p. 431.
t " The Ueolt^c Distribation of Natural Qbs in the United States,"
TroM-. Av»t.r, Imt. U.K., vol. ir. (1886-87), p. 505.
J Topley, Op. eil. p. 413.
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ORE AND STONE-MININO.
Fia. 4S.
Section turougk Findlat, Ohio. (Orton.)
r,__„„.„_ (7. Ohio shale,
uevonunjg Uppar Helderbo^ limestone.
, j. Lower Helderberg limestone.
Niagara limeEtone.
4. ' MUgoni Bbale.
ciL.jo.. Clinton limestone.
Silurian- Hudwn Rl»er Bhale.
P' Medina shale.
2. Utica shale,
^i. Trentoii limestone.
different occasione from 5a to 75 per cent, of mareb gae, 9 to 3 5
per cent, of bydrogeu, 4 to 13 per cent, of etbylic hydride with
Bmall quantities of olefiant gas, oxygen, carbonic oxide and
carbonic acid, and in one instance as mucb as 33 per cent, of
nitrogen, thougb usually this gas was absent. The pressure of
tbe escaping gae is often very
Fia. 49. ?reat, and in one case reached
450 lb. per square inch.
niokel. — Until recently
our supplies of this metal
were obtained from sulphides
or sulpbarsenidea, and espe-
cially from nickel -bearing
pyrrhotine. The discovery
- ., jjy Qnf^[^ (jf hydrated siU-
A Eld Clay . cateof nickel and magnesium
in Kew Caledonia revealed
the existence of an unsuspected source of wealth. Tbe nickel is
found in serpentine,* either at the contact of this rock with
" pockets " of red clay, or near such a contact, bat never in tbe
clay itself.
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MODE OF OCCURRENCE OF MINERALS. 61
Figs. 49, 50, and 51 are examples of various tTpee of such
deposits. In aU three cases A is the pocket of red clay, and S is
the serpentine. In Fig. 49
the nickel ore lies between Fio. jo.
the rock and the clay.
Fig. 50 there are ft number
of interlacing veins in the
serpentine forming a net-
work deposit which is quar-
ried, whilst in the case re-
presented by the Fig. 51,
the original fissures were
bigger, but less numerous,
and are now filled up with
nickel ores forming veins
20 to z6 feet in width. The ferruginous red clay often contains
the hydiated oxides of manganese and cobalt, besides chromic iron
(Fig. 19). Lareelumpsof
limonite are frequently
found lying upon the
clay, Fig. 49. The ore
wfajch is exported bss ^
from 7 to 18 per cent, of
Of still later date are
the discoveries of nickel
ore at Sadhury* on the
Canadian Pacific Railway, about 40 miles north of Creorgian Bay.
Here the ore is a nickel-benring pyrrbotine associated with
Fig. 51.
a, Huroolan strata ; b, diorite ; e, oie-body ; 1, (haft ; x x, boreholes,
chalcopyrite. These two minerals form large ore bodies (Figs.
52 and 53) in or near a belt of diorite in a district occupied
• Collins, "On the Sndbnry Copper DepoaltB," Q. J. O. S., vol. iliv.
(1S8S), p. S34, from which paper the two S^rea are borrowed. Snelus
and ColqahooD In the Bpecial volnme ot FrooeedtngE, The Iron and Steel
jaititute in America ia 1890, pp. 213, 359.
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62 ORE AKD STONE.MINING.
by rocks belonging to the Huroniao and Laurentian ayetems.
liie shftpe of the ore bodies is very irregular, bat their size is
great; some are hundreds of feet long, by a hundred or more
feet in breadth. The tvo minerals are worked and treated
Fig. S3-
a, Hnronian rocks ; b, diorite ; e, ore-masa ; f , shaft on diagonal Teio.
together, for picking by hand has been found to be impracticable
on a commercial scale, and separatioo by the ordinary washing
process is impossible, owing to the small difference between their
specific gravitiee.
Ore of good average quality contains 4 per cent, of nickel.
Kitrate of Soda. — The existence of beds of nitrate of soda,
cubic nitre, in the rainless regions on the West Coast of South
America had been noticed in
books on mineralogy for many
years ; but it was not till this
mineral was found to be a valu-
able fertiliser that steps were
taken to work it on a large
scale.
The raw nitrate of soda
(calidie) is found in beds from
6 inches to 12 feet thick, be-
neath a covering of hard oon-
glomerate (eottra) from i to 10
feet thick, as shown in F!g.
54.* It is supposed that it
has been formed by the action
of animal and vegetable
matter upon salt left }}y the evaporation of sea-water, and this
theory is supported by the fact that guano and the remains of
* Harr^, " Maohtnsrj for the Mannfactoie of Nitrate of Soda at the
Bamirei Factory. Northern Chili," Proe. Intt. C.E., vol. Ixzzii. (Segsion
1884-85). P' 337.
Fia.
4-
1
■-• .•■:-•.
— -—"-
-'-"
;-^ — ^ — ^
i-S-
M
'i
j.-j^— ■
a, soft earth; b, " caliche ";e, odd-
gjomeiate ; d, sand ; t, charae of gon-
powdu ; f, tamping ; g, safety .fnaa.
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MODE OF OCCUitRENCE OF MINERALS. 63
Inrds and fish are fouod close to the caliche, and also by the
presence of iodine, an element pertaining to the aea, id the form
of iodides and iodates.
Another theory, that of Dr. Carl Ocbsemos,* is that salt lakes
were formed by the elevation of a barrier which shut oat the sea,
that these gradually evaporated, that carbonic acid dae to
volcanic agencies converted some of the chloride of sodium into
carbonate, and that finally guano dust, wafted by the prevaihng
breeze from guano islands near the coast, brought nitrogenous
matter, which eventually became oxidised and converted the
carbonate into nitrate.
An analysts of caliche given by Mr. Harvey is as follows : —
Nitrate of soda 51
Common tail 36
Sulphate of soda 6
Salpbftte of magnesia j
Insoluble matter 14
This sample was richer than the average ; for the best caliche
contains about 40 to 50 per cent., middle 30 to 40, and pow
cflliche 1 7 to 30 per cent, of nitrate.
Osokerite. — The most productive ozokerite mines are found at
Fio. 5S.
BOTysIaw, near Drohobycs, in Galicia. The mineral occurs in an
oval area some 1,500 TOrds long and a quarter of a mile wide at
the broadest port, with the long axis, AB, running in a N. W. and
* Eng. ilin. Jonrn., voL zlvi. (tS88), p. 153.
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64 ORE AND STONB-MININO.
S.E. direction, or paraUel to the trend of the Garpathinns* (Fig. 55).
The eurrounding rocks are beds of sandstoDe tind shale of Miooeue
age, bent into a dome like a dish-cover, whilst the productive
area itself consists of the same strata traversed bj a main set of
Fig. 56.
fractiu-es in the direction AB (Fi^. 55), and numerous cross-
fractures. In this mass of shattered, crushed, and faulted rock
the ozokerite has been deposited ; it fills every crack and crevice
into which it coold penetrate, sometimes crossing the stratification
Fia. 57.
and sometimes following the planes of bedding for some distance,
and then breaking across in an irregular mannt^r (AB, Fig. 57).
The veins vary in thickness from a mere knife-edge to several feet.
Fig. 56 is a diagrammatic section along the line CD (Fig 55),
and is intended to convey some idea of the jumble of rocks between
E and F, the centre part from G to H being specially cracked,
squeezed, and faulted. The richest mines are those sunk in the
deeply-shaded part of the plan, corresponding to GH of the
section. Petroleum is found in the ro^s within the osokerite
area and also in those surrounding it for a certain distance, but
there is less on the north side than on the south.
* FoT mnch of the information oonceming Bor7iIaw, I am Indebted to
eiplanatioDB ^ven to me on the spot by Mr. A. Flatz, ' '
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MODE OP OCCURRENCE OF MINERALS. 65
Petroleum. — The conditions under which rock-oil is found
in the eartfa'a crust are precisely the same as those described in
8{]eakinx of natural gas, viz., a porooB bed for storing the
tuineral, an impermeable bed for preventing its escape, and
vei^ often an anticlinal arrangement of the strata, though this is
of less importance than in the case of gas.
The three great oil regions of the world at present are
Baku, Bormah, and Pennsylvania. I put Baku first, because
the existence of the eternal fires of the Apsheron Peninsula
on the Caspian Bea has been known for about 2,500 years,
and because same of its wells have surpassed in productivencse
anything met with elsewhere. The principal wells are in the
Fio. 58.
Balakhani-Saboontshi district, some eight miles North of Baku,
and at Bibi-Eibet, a little to the south. The rocks are of Lower
Miooene age,* and consist of sand, calcareous clays, marls, and in
places compact sandstone. The eectiont (Fig. 58, after Abich)
shows the wells on the crown of a low anticlinal. The petroleum
is found in three well-defined beds of sand ; these sands are in a
semi-fluid condition and contain salt water in addition to petr<^enin
and carbnretted hydrc^en gas. Sometimes the pressure of the
gas amounts to 300 lbs. per square inch.
At some of the wells it is necessary to pump up the petroleum,
but at others it rises naturally and occasionally wiUi great force
and in immense quantities. In fact, Tagiefi^s spouter^ in 1886
actually threw up, on the eighth day after oil bad been struck,
the immense quantity of 1 1 ,000 tons or a| millions of gallons in
twenty-four hours. The fiow then diminished and was got under
control by the engineers, and reduced to a quarter of a million
galkms a day. Kg. 59, copied from a photogiaph,§ represents a
spouting well at Baku.
The prinoipBl oil-fields (£ BurmaLH are situated near the
villages of Twingonng and Beme, about a mile and a half east of
YenanCTaung on the Irrawaddy, and 130 miles south of
Handi£iy. The rocks belong to the Tertiaiy period and are
[wobably of Miooene age, the prevailing strata being clayey eande
, vol. Isxxiii.
j Lent to me hj Hr. Borerton Redwood.
I F. Noetltne, "Beport on the Oil Fleias oi iwingooDg 1
Bnnna," Steordt of Oeot. Sunty 0/ India, voL xxU. (1889), p. 75.
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66
OBE AND STONE-MINING.
and soft sandetone. The petroleum ia found in beds of soft sand-
Btone, which, together with partings of bine clay, have been proved
to be 300 feet thick, and are probably very mncb more. The etuid-
stone is soaked with petroleum, which oosee gradually into the wells,
but certain layers are richer in petroleum than others. The
lower etratai of the formation are more productive than the upper
ones. The oil-bearing rocks are overlain by thick beds of blue
Fio. 59,
clay which prevent the petroleum from rising. The greatest depth
reached by a Burmese well is 310 feet. Noetling thinks that the
oil was produced in the sandstone formation in which it is now
found, though perhaps not in the uppermost beds.
At present there are no flowing wells, but these might be obtained
if the oil-bearing strata were tapped at a greater depth, for then
the gas which accompanies the petroleum would be under greater
pressure. Where beds lie as shallow as they do at the existing
workings, the gas has already drained off to a great extent through
cracks in the strata. The highest daily yield of a single well was
500 vift,* hut many of what can be called fairly rich wells pro-
duced upwards of 100 viss a day. The yield decreases nqndly
during the first two years to the extent of at least 35 per cent.,
and after ten or fifteen years a well does not produce more than
5 per cent, of what it did at first. The total daily production of
the two fields ranges from 15,000 to 20,000 vUt per day.
• ipi«=3o857lbs.
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MODE OF OCCURRENCE OF MINERALS. 67
Tha year 1859 marks the first discovery of petroleum on a
oommeKdal scale Id the United States, though the oil had been
known as long ago as 1627.
The strata which yield oil in Fennsylvania and New York
belong to the Devonian and OarboniferouE periods. They are
beds of sand and sandstone, sometimes coarse- grained, and are
the same as thorn producing gas ; in fact a well may often produce
both gas and petroleum, or first gas and then a little oiL In
Ohio the two chief sources of oil are the Trentou Limeotone
n^iower Silnrian] and the Berea Orit near the base of the
Carboniferons rocks.*
Phosphate of Lime. — The trade in this fertiliser is very
large, and fortunately the eourcee of supply are numerous.
Deposits of phosphate of lime are found in rocks of all ages, from
tbe Laurentian to the recent period. I may mention specially
apatite from Canada, and various kinds of phosphate from the
Chvtaceons rocks in Europe, from South Carolina, Florida, and
the West Indies.
The Laurentian rocks are the home of the apatite in Canada.
The principal mines are in the county of Ottawa (Q.), and the
mineral occurs mainly in pyrozenite, sometimes as a contem-
pcHaneons bed and sometimes as a, vein of posterior origin.
The beds are from i foot to 3 or 4 feet thick, and the veins from
a few inches to 8 or 10 feet wide.
Though worked to some extent in Bedfordshire, Buckingham-
shire, and Cambridgeebire, the Cretaceous rocks have of late
years yielded far more abundant supplies of phosphate in Franoe
tJtan in England. In the mining district of Arrast deposita of
phosphate of lime are worked in three horizons : (i) At the base
of the Gault, in the form of a bed of nodules, generally about 2
inches thick, and sometimes as much as 6 inches thick ; (2) above
the Gault, in the form of beds of nodules, 6 inches (15 cm.) to
3 feet 3 inches (i m.) thick ; (3) in the state of Band, in more or
lees regular pockets, in the upper beds of the Chalk. Thin sandy
phosphate is covered by a bed of clay with flints, above which
comes brick-earth (Fig. 60). The sides of the pockets are formed
by the chalk with Micrcuter eor-artffuimtm, or "Santonien";
whilst the fossils in the pockets belong to the base of the
"Sinonien," or chalk with Sdemnites quadralus. The pockets
are generally contiguous to each other, but vary a good deal
in depth up to 65 feet (20 m.) The phosphatic deposit is a
' Aahbumer, Op. cit. Toplev, Op. cit. Weeks, " Pettoleam," J/in<ra{
p. 458 ; and Calendar Years 1889 and 1S90, p, 287.
t Staiutique de FJndvttrie JfinA-ote el dei appareih & vapeur en Ji'mnee
tt ea Aigirie pour fonn^ 1S86. Paris, iSgg, p. 243. Pigare 60 ia taken
(mm my own notea, and differs sligbtly from the one given in tbe official
vol Dine.
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68 ORE AND STONE-MINING.
very fine yeUowinb and occasiooally white sand, which under the
microscope is found to coasast of tnmsporent concretionary grains,
A, chalk ; B, phosphatlc chalk ; C, landy phoephate of lime ;
D, claj with Sints ; B, briok-earth ; F, soil.
made up of concentric layers; its average thickness may be taken
at 3 feet 4 inches (i m.) The chalk adjacent to the pockets is
often phoephatic. M. Herle and
VTa- 6t. other geologiste think that the
phosphate ia derived from the
o lixiviation in eitu of the chalk
. with belemnites by rain water
containing carbonic acid.
' The famous beds of South
. Carolina,* besides satisfyiof; to a
great extent the wants of the
SCALES United States, are able to supply
■ ' ^ f ' '■ ' ? ? T ■' ■■' '■■"■' large quantities of the fertiliser
i : • t-t""> to other countries. They were
A,A»Uerin»rl(Ii!ocene);B.bed ^^^"^ in 1867, and owing to
of phosphatio nodolea; C, forru- t"® lacility with which they can
ginons aacd 1 D, olayey sand. be worked and their proximity
to a seaport, the trade has in-
The mineral occurs in the form <^
h to that of a man's head, in a
bed from a few inches to 3^ feet thick, the average thickness being
7 to 9 inches (Fig. 61). With the nodules are found bones of fish
and especially teeth of great sharks, together with teeth of the
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MODE OF OCCURRENCE OF MINERAUi. 69
horse and other IftDd animals. The deposit is considwed to be of
Fosb-Pliocene age.
The ezietence of valuable depodtB of phoephate in Florida*
was not known till 1887. There are four different kinds
of the fertiliser — (i) "hard rock" phosphate, (i) "soft"
phoephate, (3) "land pebble" phoephate, (4) "river pebUs"
phosphate.
Tke " hard rock" is a hard, massiTe, light grey phosphate of
lime, with cavitieB lined with secondary mammillaiy incrustatims
of the mineral. It has been produced by the alteration of
Eocene and Miocene limestone, and yields about 36 or 37 per
cent, of phosphoric anhydride (P,Oj).
The "soft" phosphate includes material resulting from the
disinte^Tation of the hard phoephate, and also highly phosphatic
sands and clays, rarely averaging more than 23 per cent, of phos-
phoric anhydride.
The " land pebble " phosphate is made up of pebbles of vartous
sizes, np to that of a walnut. They oonsiat of an earthy material
carrying pisolitic grains of phosphate of lime, or of a substance
reeembUng the haitl rock phosphate. The percentage of phos-
phoric anhydride is about 32.
The "river pebble" phosphate is found in the beds of the
preeent rivers, and also in their ancient channels. The pebbles
are blue, black, and grey in colour, and contain the bones and
t«eth of various animals. They yield from 30 to 28 per cent, of
phosphoric anhydride.
The phosphate of lime worked at Aruba and Sombrero, in the
West Indies, was originally a coral limestone ; its conversion
into phoephate has been ^eoted by the percolation of water
eontaloing phosphoric acid derived ft^m the dung of sea-fowl,
^is interesting fact is made vei7 plain by finding corals
tiumselves changed into phosphate of lime. In the island of
Bedcmda, owing to a difference in the rocks acted on by the
drainage from the excrement, the mineral produced is phoephate
of alumiDa.
Fotaasiam Salts. — The deposits of various potassium salte at
Stanfuit belong to the Buntw Sandstone formation of the
Hagdeburg-Halbentadt basin, and workings have now shown
that they attain a thickness of very nearly 3000 feet (900
metres).
The beds may be divided according to their chemical com-
position into four regions,t which in descending order are : —
* Eldridge, "A FrellminaTy Sketch of the Phospbatai of Florida,"
3ViBM. Amer. Imt. M.E.. vol. ixi (1893), p. 196. Wyatt, ThePhmhalt
of America. Mew York, 1891.
t Fakrer zma mtrtea ^gmtaaatag, /SSp, Halle a. d. Soale, 1S89, p.
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ORE AND STONE-MINING.
4. ParnaUita region. — Carnallite is the double
cbloride of potass in m and magnetlDin
(KCl. MgCl, + 6H,0J . .... 82 IS
3, Kitna-itt reguin. — Koot salt with beds of
kieserite (Mg80,+H,0) .... 183 56
a. IWyhalite tYj^ori.— Rock salt with stringa of
polyhalite (K^O., UgSO,, zOaSO,, +iH,0) 197 So
1. JtodciaU. — An exceedingly thick bed.
As is shown by th« section (Fig. 63), the edge of the camollita
region couBistn of kainite (KjSO^, MgSO,, MgCl, -1- 6H,0) ; this
a. Older rock salt ; b, poljhallte ret;loii ; e, kieserite region ;
d, Darnallite ; e, sAliferona clay ; /, kainite ; g, sylvinite ; h, gyp-
sam anil anhydrite 1 i, yonnger rock salt ; j, gypsum ; t, k vuie.
gUed marlii with thin beds of limestone and of oolite ; I, dilanum
and aUaHaiD. The depths matked are in mutrcs.
is considered to be of secondaiy origin, and so also is regarded
the eylrinite, a mixture of potassium and sodium chlorides with
their eulphat«e, which occurs in workable quantities.
Above the potassium salts is a bed of saliferous clay 26 feet (S m.)
thick, and then 290 feet (9om.)of anhydrite, which forms the floor
of the Bunter beds. At several places there is a younger bed
at rock-salt from 130 to 400 feet (40 to 120 m.) thick.
Rock-salt is worked to a small extent, but the potassium salts.
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MODE OF OCOUKRENCE OF MINEKALS. 71
especially camnUite and kainite, are the main objects of the
QniokBilTar. — The principal qoicksilyer prodviciiig mines at
tiw preeent time are Almaden, in Spain, Idria, in Camiola, and
New Almaden, in Oallfomia. There are also Beveral other mines
Id Oalifomia, and workings of some importance in Rusaia and
Italy. Peru was at one time remarkable for its quicksilver
deponts at Huancavelica, bat these are no longer worked. Ohina
poeaceeoB some little-known mines in the province of Kwei-Chan.
3^ relative importance to the world of the principal deposits
is shown by the following table, taken from Mr. Becker's mono-
graph.t
PBODOCT or THI FBIHCIPAL' DIBIBICTB, IS SPAKIBH FLASKS OP
75 Sfanibh poukds, ob 34507 kilookahhib.
ll
Cpto
1700.
'l^
'i8so.
■»
ToUllo
Alnkdeu . .
Mrt». . . .
CalUonilB . .
1564
■Sa5
517.684
1,331.477
608.743
543.643
'.091.075
75.604
i.'35.S76
3o'.5«»
1.439.346
3.965.81a
'.S5».379
1,501.113
1.439,340
'.799.4'a
>.373.86=
1,408.905
a,866.47i
8,448.650
Mr. Becker has brought together a vast array of useful facts
concerning the occurrence of quicksilver in his valuable mono-
^apb. which may be very briefly summed up as follows : — X
Cinnabar is found in rocks of all ages and of all descriptions,
viz., conglomerate, sandstone, quartzite, limestone, shale,
■date, serpentine, crystaUine schist, and basic and acidic
volcainic rocks, but it exhibits a preference for sand-
Mtoue. The quicksilver deposits are found along lines of country
marked by past or present volcanic disturbancee. This fact is
made very plain by a map of the world on which are indicated
all important oocurrences of the metal, §
Some cinnabar has certainly been precipitated from hot solutions
brooght up by volcanic springe, and it seems likely that many
of the quicksilver deposits have been formed in this manner.||
The onnabar is often found filling up incerstitial spacee of
the rock, and if the rock is sedimentary it sometimes cuts across
the planes of stratification, and sometimea runs parallel to them.
* Ptecht, ZHe ikUi-lTidtutrie von Staufurt vnd Vmgtgend. 4tfa edition,
StaMfoit, 1889.
' - ■ " G«alog7 of tbe QnicksHTer Dqposita of the I^lflo Slope,"
' " " " ' "iruej, vol. ziii. Waabington. tSSS, p. 7.
I Ibid, p, 15. I Ibid. p. 55.
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72 ORE AND STONE-MINING.
Spain. — The famoua and productive Almaden mine is situated
OD the n(»4herii slope of the Sierra Moreno, where the rocks
comiug up to the snrface are of Silurian and Devonian age.
These rocks are beds of sandstone and quartzite interstratified
with slate and a little limestone. The cinnabar occurs impregnat-
ing the sandstone ; the slate is rarely, if ever, quicksilver-beuing.
There are three principal deposits extending for a distance of 200
to Z20 yards (180 to 200 m.) along the strike, the dip is almost
vertical. The total useful thickness of the three beds is reckoned
to be 40 feet (11 m.), and the mercurial rock yieMson an average
10 per cent, of metal. It seems probable that these sandstone
beds were impregnated by aqueous solutions which came tip from
below. They may be called veins or beds according to the defini-
tions one chooses to adopt for a vein. No doubt the cinnabar is
of subsequent origin to the main part of the stratum ; but the
same may be said for the copper in the conglomerate beds of Lake
Superior, and possibly for the gold in the "banket" of South
Africa, The quicluiilver solutions deposited their metal in
cavities existing between the particles composing the sand-
stone, and I think in a case of this kind, where more tlian
90 percent, of the deposit is matter of detrital origin, it is most
convenient to speak of the deposits as beds. However, in two of
the mercurial strata there are little strings and seams, either
parallel to the bedding or crossing the planes of stratification in all
directions. Looked at on a small scale, theee strings could be
called veins, but when one has to deal with the workable stratum
as a whole it may be called a bed.
Atutria. — At Idria, in Carniola,* cinnabar occurs in the Triassic
FiQ. 63,
A, compact Bandstooe ; B, less compact sandstone lmpreg;nat«d
with cinnabar 13 to t6 feet <4 ^ 5 ii-) thick ; C, eliale ; D, thinly-
bedded asndstone.
rocks in three ways : (i) impregnating beds of shale, conglomerate
and dolomitic breccia ; (2) filling up of cracks like ordinary fissui-e
veins ; (3) in irregular veins across the mass, making a stock-
work, lipoid supposes that it was introduced by watery solu-
tions in late Tertiary times.
* Dot k. k. QtucktSbtriiitrtt eu Idria in lu-ain, Vienna, iSSi.
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MODE OF OCCURRENCE OF MINERALS. 73
Rvmia. — An interestiug and important deposit is being worked
at Ekaterinoslav in Southern Russia, a section of which is given
in Fig. 63. The cinnabar is disseminated through a sandstoae,
which liee between another bed of sandstone of a more compact
natiire and a bed of shale. Once more we have a case in which
the mercurial solutions made their way upwards along the easiest
channels they could find.
Califomia. — The quicksilver depoats of California* are found
in various parts of the State, from the extreme north to Los
Angeles. The most important mine is New Almaden, situated
about fifty miles to the S.E. of San Franci8co.
la California, as in Austria, the deposits of cinnabar are of
several types, even at one and the same mine. Thus, at New
Almaden the commonest kind of
ore-body is a network of veins and Fio. 64.
veinlets through the rock, in fact a
stockwork. If the disturbance pro-
duced a clean fissure instead of a
multitude of irr^ular cracks, then
the single rent was filled up and
produced what some would call a
typical vein. Lastly, if the mercu-
rial solutions traversed beds of sand-
stone, they depouted some of their
contents in the interstitial spaces
between the grains, and so formed
an ore-bearing stratum. All three
kinds of ore-bodies were formed by
the same process of deposition, the
difference, if I may nse the simile,
depending upon the lodgings that
happened to be vacant, and not upon
the lodger who came to take up his
abode there, nor upon the vehicle
that brought him to his new home.
The ore-bodies at New Almaden
occur close to faults filled with clay and fragments of rock, more
or lees rounded by the attrition produced by movements of the
"country." The name given to these faults by the miner is
" altas," a Spanish term referring to their usual position on the
hanging side of the deposit. It seems as if the impermeable
clay had arrested and directed the course of the ore-bearing solu-
tion as it ascended; this is highly probable, and it is an explanar
tion which has been offered in many cases when the oree of other
metals have been found to " make up against a slide."
The surrounding rocks at New Almaden are metamorphosed
* Becker, op. at. p. 317.
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74 ORE AND STONE-MINING.
sedimentB of Neocomiaa age, peeudodiorite, peendodi&base,
phthanites, aandstone, ehale, and Berpeutine. The minerals
accompauyiDg the ciiinabar are iroD pyrites, marcttsite, quarts,
calcite, dolomite, magneait-e, and rarely chalcopyrite.
The depont worked at Great Western mine, 70 miles north of
San Fr&ncisco, is a tabular reticulated mass of rock (Pig. 64),*
impregnated with cinnabar and a little native quicksUver. It
lies between serpentine and a very sUghtl; altered Neocomian
sandstone. The serpeotioe is accompanied by a holt of black
opnline rock, called the " quicksilver rock " by the miners. The
longitudinal section (Fig. 65) explains that the ore-bodiee are
separated by spaces of barren ground, just as they are in an
ordinary lode.
The Sulphur Bank mine is of interest because the solfataric
action, which no doubt caused the deposition of the cionabor, is
still going on. At first the surface was worked for sulphur,
which had been formed by deposition from sulphuretted hjrdrogen
escaping through basalt, just as it does in so many places in the
other volcanic areas. A few yards below the surface, the sulphur
proved to be cinnabar- bearing, and lower down cinnabar was
found in large quantities.
Cinnabar has since been worked from the strata underlying
the basalt. There are beds of shale and sandstone of Neooomian
age, in which the quicksilver ore is found as impregnations and
irregular seAms. The ore is accompanied by quarts, opal, iron
pyrites, calcite, bitumen, and marcasite. This last mineral con-
tains small quantities of gold and copper. Hot springs are ct
* Becker, rj). elt. p. 36
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MODE OF OCCURRENCE OF MINERALS. 75
in tfa« mine, and mftny of them give off gases, viz., carbon dioxide,
sulphuretted hydrc^eii, marsh gas, nitrogen and ammODia.
A'evtida. — From a scientific point of view, one of the most in-
tereotiog mineral depoeito in the Unit«d States is that of Steam-
boat Springs in Nevada, only six miles from the Comstock lode.
A number of hot springs exist along a series of fissures about a
mile in length ; siliceous sinter is being deposited by them, and
there are also mounds of sinter formed by springs that are no
longer flowing, or whose only sign of activity consists in emana-
tions of steam, sulphuretted hydrogen, carbonic anhydride, and
sulphurous anhydride. These solfataric gases also escape with
the mter at some of the living springs.
The sinter is found on analysis to contain many of the heavy
metals, viz., antimony, arsenic, cobalt, copper, gold, iron, lead,
maoganese, mercury, silver, and sine, some of them certainly
existing in the form of sulphides.
A sample of the water taken from a spring with a tempurature
I'arying from 167 to 184° Fahr. (75 to 84.5° C.) was analysed; it
showed weighable quantities of arsenic and antimony, and a trace
of mercury ; as it cooled it could be seen to deposit the sulphides
of antimony and arsenic together with silica.
In one part of the district, instead of sinter, a deposit like that
at Sulphur Bank, consisting of sulphur and cinnabar, has been
formed ; and it has been worked for the commercial extraction of
mercury.
Salt. — Sea water, salt lakes, brine springs and wells, sali-
ferous marls and rock salt are the sources of this very important
mineral.
The extraction of salt from sea-water is carried on in Southern
Europe and other countries, where the heat of the sun is sufficient
to evaporate the waterwhich has been led into shallow ponds ; and
the industry is fostered in many cases by the traffic in tmlt being
a Oovemment monopoly.
In South Africa and elsewhere salt is obtained from " pans" or
shallow inland lakes, which become partially dried up in the hot
seaaoD.
Natural springs yielding brine are not uncommon, and brine
weik are dug or bored so as to reach a salt-bearing stratum.
At Northwich," in Cheshire, there are two main beds of rock-
salt, each from 84 to 90 feet thick, separated by a bed of hard mari
30 to 33 feet thick. All these beds belong to the Eeuper
division of the Triaasic rocks. The amount of rock-salt mined in
England iH small, only about one-tenth of that obtained from
brine, which is pumped from flooded mines, and from wells or
boreholes penetrating saliferous strata.
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76 ORE AND STONE-UIKIXG.
SUtof. — All galena cairriee some silver, and in very maiif cases
there is enough to make the extraction profitable. Copper ores
also are frequently argentiferous : the silver in the Mansfeld
cupriferous shale has already been mentioned, and the ores
of the Butte district, Montana, are often rich in the precious
metal ; it is needless, however, to dwell upon this and similar
sources of silver, though they are of great oommercial importance.
Among well-known silver mines may be mentioned those of the
great Comstock Lode in Nevada, the Eureka and Richmond
mines in the same State, Huanchaca in Bolivia, and Broken Hill
in New South Wales.
CoTmlock Lode. — This remarkable lode strikes about north and
south and dips about 43* to the east. The vein, which is usually
from 20 to 60 feet thick and as mjich as several hundred feet thick
in some places, consists in the main of crushed and decomposed
portions of the " country " together with clay and quartz. The sur-
rounding rocks are syenite and propylite, according to Kong,* ur
diorite and diabuse, according to Backer.t The latter says that the
so-called propylite is only a decomposed form of other rocks. The
silver is found native and in the form of silver glance, polybasite,
stephanite, and occasionally pyrargyrite ; other minemls in the
vein are quartz, iixin pyrites, coppei' pyrites, besides oxides of iron
and manganese, sulphates of calcium and magnesium and car-
bonates of magnesium, calcium, lead and copper. The ore-bodies
are soft and irregular.
The heat of the Comstock lode is noteworthy. In the 2700
feet level of the Yellow Jacket mine, Mr. Becker found the temper-
ature of the water to be i53°Fahr. and that of the air 126° Ffdir.,
whilst the water of the Yellow Jacket fehaft at a depth of io6$
feet had a temperature of 170° Fahr.
Eureka-Sichtnotid. —The nature of the curious lode worked at
the £ureka-Riciimond i mines will be best understood by reference
to Fig. 66 ; much of it is a mass of crushed limestone of Cambrian
age lying between two faults, a main one dipping N.E. at an
angle of 70°, and a secondary one n-hich is much flatter.
The main fault is a fissure filled with day or with decomposed
rhyolite and clay, varying from a few inches to 15 feet in width.
It shifts the rocks many hundreds of feet, and at Eureka the
throw exceeds 1400 feet. The valuable parts of the lode are ore-
bodies of every possible shape and size, some measuring upwards
of 100 feet in all directions. Above the water level, or horizon
of decomposition by atmospheric agencies, the minerals constitut-
* King and HaguB, ''UiDiDg lodnstry," U, S. OeoL Exploratioii 1^ the
Foriieih Parotid. WaahiDgtoa, litTO.
t " Geology of the ComBtoct Lode and Wasboe District," Monograph
JIl. of U. S. GeoL Survty. Washington. 1882.
t Cortia, "Tbe Silver-lead Deposits ol Eoreka, Nevada, " Monogropk
VIII. of V. S. GoA. tinrirty. WaBhinglon, 1884.
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MODE OF OCCURRENCE OF MINERALS. 77
ing the ore-bodies, tire gale&a, ceruBsite, mimetite, wulfenite,
with very little quartz and oalcite, the remainder of the veiDstuff
being mainly hydrated oxide of iron carrying silver and goldl,
with some carbonate and silicate of zinc. Below the water level
the minerals are pyrites, atsenical pyrites, galena, blende and a
few other sulphides, besides silver and gold. One of the char-
*CALt or rCCT
H. Ore.
0. Hambarg Llmectone.
¥. Secret Canon Shale.
B. Stratified Limestone.
D. Limestone.
C ' sSe" Proepect Honntain LimestoDe.
B. Crashed Limestone. )
A. FriMpect Hoantain Qoaiizite.
acteristics of the ore is the preeence in it of gold is paying
quantitiee. It is considered by Mr. Curtis that an eruption of
rhyolite caused the upheaval which made the main fault in Ruby
Hill ; this eruption occurred in the Tertiary period. It is sup-
posed that solfataric action decomposed some massive rock and so
formed metalliferous solutions, which sscended and, penetrating
into the limestone, deposited the ore- Some of the ore is pro-
bably peeudomorphons after limestone. The average contents of
ail the Richmond ore worked in 1879 were :
Lead . . . 33 per cent.
Silver . . . 27^ oz. per ton [200a lb.)
Gold 1-590Z. „
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78 ORE AND STONE-MINING.
Hwanchaca. — The mtnea of Huanchaca are situated near the
town of that name in the department of Potosi in Bolivia, at il
great altitude, for the entrance of the San Leon adit is 13,500 feeA>
above the level of the aea. The silver lodes occur in a soft de-
composed trachyte ; the actual eilver-befiring mineral is fahlerz,
containing about 10 per cent, of the precious metal. Fortunately
for the shareholders the percental of tilver iucrefises with the
depth of the mine. The acoompaoying minerals are galena,
blende, iron pyritee, copper pyrites, with heavy spar and quartz,
and rarely a little stibnite and pyrargyrite. The main lode runs
about ea«it and west, and is from 3 to 10 feet in width (i to
3 metres) ; it has three particularly nch shoois which incline
from west to east. The total output of silvei' in 1S87 wop
4,ii4,SEO OE. (131,086 kil.).
At tiie famous Potosi mines also, the silver oceun in a fahlen:.
Broken lliU. — The mines at Broken Hill are remarkable for theii-
enormous output of silver and lead during the last few years.
They are utuated in the Silverton or Barrier Banges district of
New South Wales, near the western boundary of the colony. The
deposit is generally spoken of aa a vein or lode, but there seems
some doubt whether this appellation is correct ; further develop-
ments of the workings may prove thac it is a bed. The vein, if it
may be so called, runs, rouglily speaking, N.E. and S.W. ; the di}i
varies, being sometimes to the S.E. and aumetimes to N.W., and
is always steep. At and near the surface, the vein * consisted of
dark-hrown heematite, often blackened by psilomelane, together
with ferruginous carbonate of lead, kaolin, and the chloride, chloro-
bromide and iodide of silver; besides these there were pyromorphite,
atacamite, cuprite, mal&clute, and chrysocoUa, with quartz,
quartzite, and garnet rock. Below this upper weathered zone,
containing minerals usually met with in goazans, come the
sulphides, especially galena and zinc blende, together with pyrites,
chalcopyrite, and mispickel. Some of the galena is so intimately
mixed with the blende as to render its separation by any ordinai-y
dressing process very diBicult, if not commei'cially impossible.
Ores of this class t contain 15 to 40 per cent, of lead, 15 to 30
per cent, of zinc, and 8 to 24 ounces of silver to the ton, and at
present the owners of the mines have not settled what method of
ti-eatment will prove the most efficacious ajid economical. The
width of the lode is from 15 to 316 feet. The enclosing rocks are
gneiss and garnetiferous mica and talcose schists, and tJie vein lies
* John Provie, " Report an the Broken Bill Proprietary Co.'s Mines,"
contained in ths Compsnj'H Beportt and SlatemtBlt 0/ AecourUt /or Iht Jfalf
Vtar ended Nov. yolh, 1 886. Melbonnie, Victoria. Jamieson and
Howell ■' Mining and Ore-treatment at Broken Hill, N.S.W.," iVoe. Jnit.
C.E.. vol. oiiv. (1892-93), Part IV.
i- Schnabel. " Vorschl^e zar Verarbeitang aastralisclicr silbeihaltiger
Blende- Blelglanzene," li. u. h. Z,, iSSz, p. 429.
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MODE OF OCCURRENCE OF MINERAIiJ. 79
parallel to tbe plaoefl of foliation. In the aereo years endiiif
list May, 1S93,* the prindpftl mine, owned by tbe Broken Hill
rn^Mietary Company, prodoced 9S4, 349 tons of ore, which yielded
36,513,445 ounces of silver and 151,945 tons of lead, worth
altogether ^8,252,138, of which ;£3,896,ooo has been paid in
divideode and bonos.
Silver-bearing Sandtt&ne. — Silver is found in workable
quantiUea in certain beds of sandstone, interstratified with shalp,
conaidflied to be of Triassic age, at Stormont in Southern Utah.f
Alt the strata contain at least some traces of silver, but
three or four special horizons were rich enough to be worked ;
even here the precious metal was distributed irre^larly, And
mining was confined to rich "shoots" or chimneys, which some-
times followed one particular stratum of the general ore-bearing
bed, and sometimes cut acroes it. It is supposed that silver-
bearing solations came up through the rock, and flowed along
the portions which th^ found most porous. The precipitation
of tbe silver was, perhaps, caused by the presence of organic
matter. The metal exists in tbe form of sulphide and chloride,
though there is a little native silver. These minerals are dissemi-
nated through the sandstone, and occur especially along the
planes of bedding and of fracture. The c«e-beds were mined for
a thickness of six, eight, or even ten feet, though the whole of
the rock was not always worth milling. Much of the ore milled
about 1879 contained from 10 to 30 oz. of silver per ton, and
yielded by amalgamation 15 to 24 oe.|
Gar^Ad Mine,§ near Calico, California, owes its existence to a
network deposit or stockwork. Tbe surrounding rock is lipHrite
or rbyolite, which is traversed near by a number of irregular
fissures. The cracks contain kerargyrite and embolite, with chiy-
socolla and heavy spar, and the stockwork may be described as a
breceiA of Itparite cemented by the argentiferous and other
minerals.
Slate. ^Wales is so renowned for its slate that the example of
a deposit of this mineral may fairly be taken from the Princi^Uty.
About two-thirds of the Welsh slate are got from beds of Cambrian
age in Carnarvon shire, and one-third from beds in the Lower
Stlnrian (Oidovician) rocks in Merionethshire. The quarries in
the former county are mostly open, whilst in the latter the local
conditions have led to the adoption of true mining, especially at
Festinit^, whidi can boast of the most extensive underground
• Ompani/'t Baif- Ytarly Report, dated July 27, 1892. p. 86.
t R. P. Rot.hwell, " Report od Cba SWtinont Silver Mining Company's
Property, Silver Beet." Utab, 1S79.
J JaclDMD, " Silver in Sedimentarv Rocfa," Report of the JDireaort of the
U.S. Mint. Washin^toD, iS8t, p. 384.
I W. liodgMii, " Tbe surer Mines of Calico, California," Traat. Aiaer.
Utt. M.E, ToL IV. (1886-87) p. 725-
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8o ORE AND STONE-MINING.
workings for slate in the world. The northern part of the parish
of Festiniog ii occupied by the outcrop of a thick series of slaty
rocks (R, f^g. 67*), resting upon coarse volcanic agglomeo^te, H,
and intei-atratified with thinner beds of volcanic ash, and inter-
sected from time to time by intrusive dykee of diabase, locally
called whinstooe. The beds have a general northerly or north-
westerly dip of 30" to 35°, whilst the cleavage planee throughout
the district dip at a greater angle than the bedding by about 15°,
and very nearly in the same direction.
Owing to peculiarities of texture, due apparently to the fineness
of the sediment deposited npon the old saa-hottom, certain beds
or sets of beds furnish a slate which can be split into very smooth
sheets, as thin as y\ inch and even lees. Any set of beds worked
as a whole is knowu locally as a " vein," hut it does not neceeearily
furnish saleable roofing material for its entire thickness. Some-
FiG. 67.
A, granite; B, Tremadttc rocks ; CQarthGrit ; D, LoverSUte ;
E, Areofg rocks above the grit ; F, Lower Agglomerate; 'S', Middle
AJ^Iomerate ; G*, Middle Slate; G, Upper 31ate ; H, Upper A^lomer-
ate ; E, Llandello slates.
times unprofitable rock is taken away above the good slate in
order to reach a firm layer, such as a bed of volcanic ash, or a
" whinstone" dyke, which caa be trusted to stand as the roof of
the underground chambers, and at others the fine-grained slate
has beds of coarser sediment interstratified with it, which cause
irrt^larities in the planes of cleavage, and so give rise to inferior
products.
The " Old Vein," famous for the quality of its slates, is lao feet
(36.5 m.) thick at the Oakeley quarries, where other " veins " of
less importance are also being worked (Fig. 68). At some of the
other quarries of the district, beds of slate in the underlying
rocks of the Arenig series are found to be profitable, such as G'
in Fig. 67, and i m Fig. 68.
The property possessed by the slate of rending along planes,
cutting across both dip and cleavage, must not be forgotten, for
upon it depend both the getting of the rock and the direction
given to the supporting pillars. At the Oakeley quarries the " line
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MODE OF OUCURRENCE OF MINERALS, 8i
of piUAriog," that is to say, the direction along which the cross-
rending or rifting takes place most readily, rune about N. 7° W.,
whereas the dip is N. 40^ W. The planes along which the slate
rends or " pillars " beet are at right angles to the cleavage planes,
not quite vertical, but dipping at a high angle to the eaet; the
Gonaeqaence is that the eastern side of an underground chamber
at theee quarries overhangs sUghtly.
The value of a slate bed, or " vein," depends greatly upon the
number and natdre of the natural jointe by which it is intersected.
If th^ are very numerous, the workings will yield blocks too
small for making the larger and higher priced sizes of slatee ; if
they are rare, more expense will be incurred in severing the
material from its bed. Dlsturbancea of the strata resulting in
Section or the Oakelbt Qoaheibs, Febtinioq "
Ag', Ag', Ag, TOlcaoic BgelomBrates ; i, slate vein worked at
Wrjaganand New Quarry, Diphwji ; 2, new or soath veto; 3,
old veto ; 4, lA vein ; 5, back vein ; 6, north vein ; WD, " whin-
stone" djkes (diabase) ; F, porpbTTite ; As, Tolcanieash.
fissures filled eilJier mechanically with clay and broken slate, or
chemically by the deposittou of quartz, may render the " vein "
utterly worthless in places ; but, as in the case of other bedded
depOBits, changes in productiveness are far less frequent than
with lodes.
Suiplrar. — The industrial sources of sulphur are : (1) deposits
of native sulphur, and (2) iron pjnrites.
Native sulphur occurs as a product of volcanic emanatione, and
in Mdimentary deposits.
The amount of sulphur obtained from depoeite of volcanic
origia is small ; but this mode of occurrence is of geological
interest, because we can obeerve the processes of accumulation in
actual operation, whereas usually the secrets of Nature's laboratory
are hidden from ua
• Hade by Mr. G. J. WUIiamB, F.G.S.
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83 OEK AND STONE-MINING.
DopoBtaof thiB kind are generally found at or near spent vol-
canio enters, th« emanation of aulphurous gases being one of tb^
lost agne of actiritv. Sulphur has been worked on a small w*!©
at the famous Solfatani of
Pio. 69. Poizaoli, near Naples, at
■^-^ Vuloano, one of th« lipari
,_— C~~- J '''-'-"^ii'j liBlanda, and in volcanic re-
(•/"^ ■' - ,-,•■ '■^ih") gions in Tarioufl parts of the
Ht. V, WB'' ^-flf^ world.
^''•V 11 li In Iceland a little column
" \\ 'if 1 ^' vapour may be seen iMO-
Js»**-^^)i:'^--^r^t«w <^ '°K '""" ^^ ground, and the
i^'wltt il'ii'i'i I'ifc • I ''Tb?^! r ^*'" ™°i°^ around it con-
sists of a crust of sulphur
covered by a thin coating of
_ _ blown sand. The gaees com-
'^'°".'''% ^u* =^« " ing out of the earth cont&in
• c . ° ' '■ ° ' sulphuretted hydrogen in
addition to eteam, &nd
when they reach the surface some of the former is ozidisedr
and sulphur is deposited aa shown in Fig. 69 ; a is the under-
lying rock, a decomposed lava, 6 clay, c the native sulphur,
and d sand blown over the little mound, and retained by the
moisture due to condensation of the steam. I have already alluded
to Sulphur Bank and Steamboat Springs, in speaking of qnick-
ailver.
Seams or beds of sulphur occiu' in Sicily, Calabria, the Bomagna,
and other parts of Italy, and also in Croatia, Spain, and France.
By far the most important beds are those of Sicily.
The accompanying section, borrowed from Baldacci* (Fig. 70),
shows a section of the countrj- near Caltagirone. The letter a
Fig. 70.
deuotes beds of clay (Tortonian), h is tripoh (Sarmatian), e is the bed
of sulphur- bearing limestone^ d white marl or marly limestonewitb
foraminifera, called " trubi " in Sicily ; «, blue clay ; /, calcareous
tufa. The beds a,b,e are considered to belong to the Upper
Miocene, whilst <^ is placed in the Lower Pliocene, and e KaAfva
the Upper Pliocene.
The beda of tripoli are made up chiefly of the siliceous remains
of radiolaria, diatomacen, and sponges, together with marl.
* Dacrixiont ffeolegka ddP lula di SiclHo. Bome, 1886, p. 396.
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MODE OF OCCURRENCE OF MIKERAIS. 83
The sdlphar-bearing bed varies from r hard white limeatonA
to a grejT marly limestone, and from this to & marl ; the aulphor
iteelf is always in the native Btate, forming little globules, lamuuB,
or imgiilar leasee, varying in thickness and extent. It Is oftea
crystallised, and associated with it are celestine, gypsum, caldte,
and arragonite ; in the clayey beds there is also bitumen, which
is objectionable, as it gives a dark colour to the product obWoed
by liquation.
The thickness of the sulphur seams varies within very wide
liskits. Beds 20 feet thick are common, and at Lercara the
stratum reaches the enormous thickness of 164 feet (50 m.).
Frequently there are two or three beds ; at tbe great Somatino
mine, for instance, the deposit is 100 to 115 feet (30 to 35 m.^
thic^ divided into six separate seams, from 6 to 25 feet (3 to 3 m.)
each, l^ partings of barren rock.
As a rule, a bed leas than 5 feet (1.50 m.) in thickaeae is not
worth working, unless it is exceptionally rich or conveniently
ntoated for working.
The yield of the sulphur rook may be taken on an average at
about 22 per cent., though occasional rich seams give as much as
45 pw cent.
I^uodi* snbdividee the seams according to quality, thus :
AaioDDt of Bnlnbni.
Bt Ajtiljila. Aotoja Yield bj till KilBN
Peroanl. F«[ cent.
Very rich . 30 to 40 20 to 25
Rich 25 „ 30 IS „ 30
Poor 15 .. 25 'o I, 'S
The Sidlian deposits are considered to have been formed by
E^mical precipitation from aqueous solutions in lakea.f
Tbe deposits on the Italian mainland also belong to tbe Miocene
period, and the sulphur beds are known to extend for a long
distance on the east of the Apennines. Often thera is but one
•earn 6 to 10 feet (2 to 3 m.) thick ; tbe rock is poorer than in
Sicily, for it contains only 18 to 20 per cent., and the yield by
the kiln {caiearone) does not exceed 12 per cent, on an average.
After the description of tbe deposits of cupreous pyrites at
Bio Tinto, it is quite unneceflsary to say anything further about
such Bouroes of sulphur. Iron pyrites containing no copper is
aometimee worked, and Cae Oocb Mine, in Carnarvonshire,
aSbrds an example of a depoeit of this kind.
Tin. — ^Tin on is obtained from veins, beds, and a variety of
irregular deposits.
It is natural for an Englishman to take his iUustratioiu of
• iUT tMtrazioat drilo Soljo in Sieilia. Florence, 1873, P- lo.
t " Notiile mille oondliianl dell' Indnstiia solflferB e di quells ad esta
■Sni," JtiviMta dti lercixio minerario nel tSSS. Florence, 1890, p. elxv.
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84 ORE AND STONE-MININW.
veiDB from Comw&l). Figs. 71 and 72 represent two veins in the
paxish of St. Agnes.*
• h i
— tn
A, aUte (HScu) ; B, eopel— that U to
say, slate altered into a bard dark-
ooloored mass of quuti and schorl,
with short lenticiilar veins of qnartz,
and traversed b; little strings of oaa-
aiterite and chlorite ; CC, the Under,
oonsistltig' of quartz, cassiterite, chlo- . . - .
rite, a little iron pyrites, and pieces of containing aboat sj per cent, of
AA, slate (ifciltat); BB, eapri
ss above ; CC, smell leader or
rein of tinstone and qoartz ; DD,
main feotirr, consistin); of iron
ind chlorite.
Many of the veins in granite are due to the alteration of tbe
rock in the neighbourhood of fissuree, aa has been ah«ady
explained ^Fig. 3). The so-called corionoa of the St. Ivee district
are essentially masses of stanniferous schorl rock, very irregular
in shape and connected with a main lode by a cross joint or fissure.
TOey seem to be altered granite.
Mulberry Mine, near Bodmin (Fig. 16), has already been cited
as an instance of a network deposit or stockwork.
At Altenberg, in Saxony, there is a huge mass of tin-bearing
rock, locally known as "Zwitter" or "Zwittergestein." VonCottat
has shown by analyses that it is merely granite, which has loet
about 3 per cent, of silica and z per cent, of potash, and has
taken up about 4 per cent, of ferrous oxide and \ per cent, of
oxide of tin. It has been worked for tin during a period of
several centuries.
Beds containing tin ore in the form of rolled pebbles and
sand occur with the aUuvial deporats of existing valleys in
many countries. The principal Cornish deposits have long
• C. Le Nave Foster, " Reroarka upon Bome Tin Lodes to tbe St. Affnea
District," TWnu. R. Oeot, 8oe. CbnttetUl, voL Ix. p. 206.
t B. von Gotta, " Die Stdngnippe Im Hofe der BeTgafcadcmle.'' J^-
fcAr^ cum hundtr^ith''igeH JvMavm dtr Kani^ ^ch. BergahalmtU cu
fVe&trg. Diesdeo, 1886, p. 157.
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MODE OF OCCUitRENCE OF MINERALS. 85
been exhausted, though as lately as 1873 tin ore was raised
from a bed aoder B«etroiignet Creek, a branch of Falmouth
Harbour (f1^. 364). In the Malay Peninsula alluvial depodte or
" stream works " ai-e yielding large quantities of ore ; and Now
South Wales is remarkable not only for ite recent stanniferous
alluvia, but also for much older deposits, which, like the ancient
gold gravels, have been preserved under a covering of basalt. The
accompanying map (Fig. 73) shows part of Vegetable Creek, New
South Wales ; the stipphag by the side of the creek represents
the tin-bearing alluvium, which has been worked by open pits.
The rest of the country is granite, except the shaded part at Ati
Fig. 73.
which denotes basalt ; this flowed down an old valley and filled it
up entirely, as shown by the section (Fig. 74). The hard cover of
lava has preserved the stanniferous alluvium and the white clay
from denudation. Old alluvia of this description are known as
" deep leads."
Zino. — Zinc ore is found in veins, beds, and irregular masses.
Liiderich mine, situated near Bensberg, on the right bank of
the Rhine, not very far from Cologne, derives large quantities of
blende from a huge vein in the Devonian rocks. The actual
horizon is that of the " Lenneschiefer," which is classed as Middle
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ORE AND STONE-MINING.
Devoni&n. The roclis are slate, mterstratified
with sandstone a.nd slaty sandatoDe. The lodee
of the district, as a rule, run E. and "W., or a
little north of west ; the Liiderich miue, however,
ia an exoeption, for the lode strikee, roughly
speaking, north and south. It may be best de*
scribed as a zone or belt of broken and disturbed
rock, 40 to 50 metres wide, containing ore in
irregular veins and nmssea. The ore-bodiee are
usually lenticular in shape, dying out gradually
in every direction ; they sometimes consiBt of
solid blende for a width of several yards. The
minerals found in the lode are : blende, galena,
copper pyrites, iron pyrites, fohletz, quartz and,
rarely, tjialybite. The fahlei'z is silver-bearing,
and the blende always contains cadmium,
and occasionally gallium. The total production
of the mine in 1890 was 8304 tons of blende
ready for the smelter, and 423 tons of lead ore.
It is therefore of more importance as a zinc
mine than any in this country.
The largest sine mine in the British Isles at
the present time is Minera, near Wrexham. It
may be safely inferred from its name that it
was worked during the Boman occupation of the
country ; but the object of the mining in those
days, and, indeed, until quite a recent date, was
lead and not zinc ore.
The surrounding rocks are Carboniferous
Limestone and Millstone grit, and an the lode
is a well-marked fault, the Coa) Measures are
met with on the downthrow side. There are
two principal veins running parallel to one
another in a general N.W. and S.E. direction,
and dipping steeply to the N.E. ; and where pro-
ductive they are nearly perpendicular. They
vary in size from a mere cleft in the rock to a
width of 1 8 feet ; a fair average size is 6 feet.
Besides these two main veins there are numerous
branches and ramifications. The valuable mine-
rals are xinc blende and galena, and, as would
be expected, the matrix consiste mainly of calc-
spar. In the upper parts of the mine to a depth
of 230 yards, galena was met with in large quan-
tities, and the mine made considerable profits upon
it« sales of lead ore ; but during the last twelve
years blende has greatly predominated. At the
pres^ittimeitmaybe reckoned that the "stnfT"
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MODE OF OCCURRENCE OF MINERALS. 87
brought up from the mine yieltls 7^ percent, of blende and i^ per
cent, of galena. The total prodaction of the mine in 1891 was
5433 tone of zinc ore and 906 tone of lead ore ready for the
market..
At 'Ammeberg, near the northern extremity of the Wetter
Lake, in Sweden, zinc blende occurs in beds. The emround-
in^ rock ie a schist consiBting of felspar and quartz, with a little
mica, which may be r^arded as a variety of gneiss. The blende
is accompanied by iron pyrites, pyrrhotine, hornblende, chlorite,
garnet, tourmaline and other minerals, and in places it maybe
plainly seen to replace the mica of the gneiss. The Ammebei^
beds are worked on a large scale by the Tieille Montagne
Company. '
Diepenlinchen mine, near Stolberg, in Fruasia, is interesting
not only on account of being a large producer of zinc ore, but also
because some of it is derived from a great stockwork, a form of
deposit lees common with zinc than tin. The stockwork consists
of an oval mass of limestone, about 120 metres long from east to
west, and 50 metres across from north to isouth. In this region
the limestone is full of cracks, which have been filled up with
zinc blende, and this mineral is also seen lining small irregn-
lar cavitiee in the rock ; judging by its structure it has been
deposited layer after layer, and probably from an aqueous solution.
'Hie rock is so intermingled with blende that the whole of it
has to be worked away, and the separation of the valuable con-
stituent from the waste is effected by dressing.
Fig. 15 IB a section across one of the irregular masses of
calamine at Aitenberg, in the neutral territory of Moresnet, be-
tween Belgium and Russia.
FAULTS. — All kinds of deposits are subject not only to
irrtt^arities dependent upon their mode of formationf such as a
gradual thinning out or thickening,
but to others which have taken place Tia. 75.
subsequently. Sometimes a bed, ^ ^
sndb as AB, has had a portion de- -'w-+ *— v \-h^l—\_ t^ -)->
noded by a current during the
general period of deposition. Such
ao occurrence is called a " wash ^
out " fault, or " dumb fault "
(fig. 75)-. .
In addition to irregularities of this kind, deposits suffer from
the disturbances which have taken place in the rock mnnnini which
contain them. Shght undulations of the strata are common, and
when the distorbfuice has been greater, the beds are bent into
arches and troughs, or antkUnala and tyndinaie. Further, a
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88 OEE AND STONE-MINING.
Uter&l pressure m&y have been sufficient to cauee great crumplings
utd coDtortioDB, and in places to invert the order of succession, in
other words to make the newer beds lie under, infitead of above,
the older ones. When bods are much bent there is often a
thickening in the anticlinals and synclinals, and a oorreeponding
thinning in the connecting limbs.
A bed may be so folded and crumpled as to lose its original
sheet-like form in places, and assume
Fid, j6, the shape of an irregular mass.
This may happen even with a coiU
seam.*
The disturbancea of the rocks may
finally produce rents, acccMnpanied by
displacement, which are caileifatUU,
heavei, throios, or didt*.
We will take the case of a bed
(Fig. 76). AB is a seam which ends
suddenly at B, whilst the continua-
tion is found at a lower level, CD. The two parte of the bed
'must have orifiinatly been on the same horizon, but subsequently
a fracture took place along the line XY, followed by a movement
of one side or both sides. As a rule the portion of rock on the
upper or hanging wall side appears to have slid downwards, or
the under portion to have been thrust upwards.
The rent may he clean, sharp, and nairow, with the shifted
portions of rock touching each other ; or there may be a soc-
FiG. 77. Fig. 78.
cession of fissures producing a step- like arrangement of the beam
(Fig. 77) ; frequently the cracks are filled up with clay, or there
is B, zone seveml yards in width composed of broken fragments
and clay, produced by the attrition of the sides of the two rock
massee (Fig. 78). Signs of rubbing may be seen upon the walls
I Mliimg, vol. i. p, 6,1, and Atlas, Plate VIII.,
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MODE OF OCCURRENCE OF MINERALS. 89
in the form of grooves and scratches, or polished surfaces known as
!' slickensides." A fault is of the aame origin as a mineral vein ;
the filling is due either to mechanical or chemical agencies, or to
both combined, but does not happen to bo worth working com-
mercially. The prolongation of a valuable mineral vein may
be unproductive on entering certain rocks, and will then be looked
upon as a fault. Thus, some of the
mineral veins of the Carboniferous Fig. 79.
Limestone in Flintshire appear to be
continued an faults in the Coal Measures.
The thrmo of a fault is measured by
the amount of vertical diaplacemeitt. If
XY is a fault shifting a bed AU (Fig.
79), draw BE vertical and CF at right
anglee to BE. Then BF is the vertical
downthrow, CF represents the horizontal
displacement, and BC the shift along the
line of dip.
The study of faults is important be-
cause the miner working the bed AB (Fig. 78), wants to know after
reaching the fault XY where to find the continuation of the de-
posit. The rule is to follow the greater aogle. The angle ABY
is greater than the angle ABX, and the missing part may be
expected somewhere along the line BY, If the miner were wcffk-
ing from D to C, the same rule would apply, for the angle DCX
is greater than 1)0 Y.
This rule gives the direction of the throw, but affords no indi-
cation us to its amount, which may
vary considerably. If the beds are Fig. So.
distinctly marked by lithological pe-
culiarities or by fossils, the miner
can obtain useful information by
driving through the fault into the
rocks upon the other side. Suppose, a
for instance, that a valuable bed of
shale AB (Fig. So) ended oS suddenly
against a fault FG. A continuation
of the workings in the direction AB
comes upon a bed of conglomerate,
which the miner recognises as one
tiiat is usually 40 feet above him. He can fairly conclude that
the distance BE at right angles to the prolongation of DC will
be 40 feet. As the respective dips of the bed and of the fault are
known, the angle EEC can at once be ascertained and the distance
BC calculated.
The throw of a fault is not always the same ; it varies along the
strike, and finally dies away altogether. This will be understood
by making a slit with a penknife through a sheet of cardboard
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90 ORE AND STONE-MINING.
or india^-rubber, and pressing down one aide ; the throw dimin-
iabes from a maximnm at C to nothing at A and B (Fig. Si).
Change in the direction of throw may be due to the beds on
Fia. 81. Fig. 82.
7 ^
one aide of a fault being mickered or bent, whilst they are flat or
dip evenly on the other (Fw. 82).
The distance to which some faults may be traced ie verj- gieat.
The Oorze-ArB-MetE fault* extends from St. Julien in I^wce,
right acTbfls Lorraine to beyond the Saar, near Wacheren, a. total
dietance of 53 miles (85 kilometres), and another fault in the
same district is known for 28 miles (45 kilometres). The throw
of a fault varies from a few inches to hundreds and even thousands
of feet.
Near a fault a bed is often found to dip more steeply, as if it
had been bent before it broke. This is the case with the great
iron ore bed of Lorraine.t The usual dip is very alight, only i to
I J in a hundred, but near faults it is decidedly more, and reaches
4 in a hundred.
The rule that the portioh of the hanging wall side has shifted
downwards along the dip of the fault is not without exceptionn,
Fia. 83. Pig. 84,
especially in localities where rocks are much bent and folded.
Heim shows by a series of figures the various stages in the pro-
duction of a displacement of this kind, which is known as a
reverted or overlap fault (Fig. 83). Fig. 84 also shows a reversed
fault.
As mineral veins have been formed in re^ous where rock,s
have been broken and dislocated, it is only natural to ^>ect that
* Wandesleben, " Das Vorkommen der oolitiaoben Sisenerae (Minette) ia
Lothringen, Luxemburg nnd dem ustlichen Frankreiclie.'' J-rtlidiriji
und VirhandtuBj/en Dcr IV. AVgtmtint IhuUtke Bergmannttas in Hade
(Saalt.) Halle, 1890, p. 30I- •
t Ibvi. p. 301.
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MODE OF OCCURRENCE OF MINERALS. 91
l&ey also should be Affected by movements and sHftiDgs of tbe
flKTtb's croBt. Owing to tbe fact that veinB are usually highly
indiDed, and that there is often much difficalty in deciding how
tbe diiilocated rocks iitted together before they were shifted, tbe
vein miner speaks of faults in different terms to the bed miner.
Jnstead of talking of downVirowg and upthrows, be looks at tbe
shift pit>duced sideways and calls it a
AttHW. The miner driving a horizontal Fia. 85.
tannel AB (Fig. 85) in a vein, comes
into the fault XY at the point B, and
finda that his vein ends off suddenly ;
in order to regain it he is obliged to
drive sideways in barren ground from
B to C, where ha meets with the con- ^
tinuataoD along the line CD. Tbe /
miner says that there baa been a left- I
Jkand heave, because whether driving /
in the direction A to B or D to C, y
he finds the faulted portion to the , Pu«-
left band. It is evident in many cases from tbe atriations upon
tlie walls of tbe faults, that the displacement of tbe two adjacent
rock masses took place, not along tbe line of greatest dip, but in
ft diagonal direction, causing a shifting sideways as well as
downwards. Nevertheless, where beds or veins are not horizontal,
a mere shift along the line of dip is suffi-
denttocaneeaAeaoesideways. Thlswill Fio. 86.
be understood from Fig. 86. Let AB ■
and CD represent two portions of tbe lode
dislocated by the fault EF. The point B'
cmreeponded originally with B, and the
dislocstion was caused by tbe simple
sliding of B' along the line of dip of the
fault. Here again the miner would speak
of tbe heave as taking place to tbe left.
The subject of the heaves of lodes and
beds has been elucidated by Schmidt,* Zimmermanat and
others.
Zimmermann's rule for finding tbe lost part of a vein on the
other side of a fault is oa follows :
I^y down upon paper the line of strike of tbe lode and the
line of strike of tbe fault (eroM-eourte), and by construction
aaeertain the horizontal projection of the line of their intersection ;
from the point where tbe cross-course was struck by the lode,
draw a line at right angles to tbe strike of tbe former and
directed to its opposite w^l. Notice on which side of the line of
* Ttoorw der VertehMmng allertr Qaitnt. I'irankfort, iSto.
t IHe WUiUrinuridUuag vtraorfener Odnge, Lager mid Flttee. Dacm-
Hadt and Leipsic, 182&
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92
ORE AND STONE-MINING.
intersectioD this peipendicular falla, and, after cutting through
the crasB-course, seek the heaved part of the lode on that side.
Thvn let AB (Pig. S7) represent, at eome given depth, the line
of strike of a fault or cross-
Fig. 87. course dipping east, and CD
the line of stnktt of a lode dip-
ping south, and we will sup-
poae that in driving from C to
D, in a westerly direction, the
fault has been met with at D.
Knowing the dip of the lode
and that of the fault, it is easy
' to lay down, on any given scale,
A'B' and O'D', the lines of
strike of the fault and lode
respectively at a certain depth,
~ say ten fathoms, below AB.
The p<HUt D", where A'B' and CD* meet, is one point of the
line of intersection. Join D and D" and prolong on both sides.
The line MN repiesents the horizontal projection of the line of
intersection of the two planes. At D erect DE at right angles
to AB, and directed towu^s the opposite wall of the fault. &B
D£ falls south of MN, the miner, after cutting through the foolt
would drive in a southerly direction, and eventually strike the
lode again at F. It will be at once understood that if the miner
were following the lode &om G to F, the perpendicular would lie
to the north of the line of intersection, and following the rale
he would drive in that direction, after cutting through the fault.
When several faults dislocate lodes one eStor the other very
great complications may arise.
Fig. S8* is, fortunately for the miner, an unusual instance of a
a of faults.
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CHAPTER II.
PROSPECTING.
Ctumca discoveries. — AdvenUtiooB finds. — Uses of geolo)^. — AssocuLtcd
miiteialB. — Soifftoe indicatioiu : form, colour, gozzsos, Epriiigs, iodica-
Uto plants^ bmrowB of b ni majg. — Sboading. — H ushing. — Piercing.^
Lode-Ughts. — AlteredTegetation and other indloationa. — Old working,
■lag heaps, nins.— Namea of places,— Divining-rod.— Dipping needle.
— Q'uUBol'ons of tbe prospector.
OLanoe DisooTeries. — ^Tfaa number of discoveries of valuable
mineral deposits b^ pure chance is very great. I will mention a
few cases, mostly recent, taking the minendfi in alphabetical order.
Amler. — Pieces of amber cast up on the ehores of the Baltic
after storma, no doubt were the first sources of supply of the
mineral, and eventually led to a search for the parent beds.
Cobak. — The cobalt ore recently worked in Flintshire was dis-
covered in 1870, by Mr. Gage, who happened to test with the
blowpipe some black matter which formed strings in the Carboni-
ferous Limestone.
Copper. — The owner of a sheep run on Yorke's Peninsula,
South Australia,* picked up some atacamite on the coast in 1859,
and became convinced that there were deposito of copper ore
inland. In 1 860 he came across the workings of a womlnt which
had thrown out a quantity of this green ore m making ita burrow.
Pits were put down, and the great Wallaroo lode was thus dis-
ooverod. Other lodes in the district were afterwards hit upon in
the same way, or from green ore thrown up by some burrowing
insect.
Diamcmdt. — The fate of South Africa has been wholly changed
t^ the finding of diamonds. Mr. O'Reilly, a trader, describes his
discovery in these words : —
"In March 1867, I was on my way to Coleeberg, from the
junction of the Taal and Orange Rivers ; I outspanned at Mr.
Niekerk's farm, where I saw a beautiful lot of Orange River
stones on his table, which I examined. I told Niekerk they
were very pretty. He showed me another lot, out of which I at
once picked the 'first diamond.' I asked him for it, and he told
me I could have it, as it belonged to a Bushman boy of Daniel
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94 ORE AND STONE-MI KING.
Jacobs." Mr. O'Reilly then sent the stone to Cape Town for
ezamination, wheo it tamed out to be a true diamond, worth
iTsoo*
The value of the diamonds produced annually far exceeds that
of the gold of any one of our colonies.
Gold. — The stoiy told of the finding of gold in California, in
1848, is that Marshall, who was Buperintending a sawmill, haj^
pened to see something guttering in the mill le&t. It turned out
to be gold. He foimd more nuggets, and soon the discovery was
noised abroad.
In Australia the first discoveries of gold were by chance.
The attentitm of Dr. Plassard was directed to the existence of
gold in Venezuela from seeing edme specimens in the possessifm
of A native.
Iron. — Traces of soft hematite, noticed among the roots of an
overturned tree, led to the discovery, in 1891, of the important
Biwabikt iron mines of the Mesabi range, Minnesota.
Nickd. — The Sudbury nickel deposits were discovered in
making a cutting for the Canadian and Pacific BaUway,aDd even
then it was the copper which first attracted notice.
PhotpiaU of Lime. — In May 1886, & geologist, M. Merle, took
it into bis head to analyse the sand of an apparently abandoned
pit, which had been worked for centuries in order to give bricks
a violet tint much esteemed in the neighbourhood. He found it
contained 77*85 per cent, of phosphate of lime. This was the
origin of the workings tn the Upper Chalk at Beauval, in the
department of the Somme.t
The discovery of the phosphate beds of Flarida§ was made in the
autumn of 1889 by an orange-grower, who out of curiosity sent
to a chemist a sample of the white pubsoil of his grove; this
turned out to contain 80 per cent, of phosphate.
. QvicksUver. — The Redinglon Quicksilver Mine.H in California,
was discovered in making a cutting for a road.
Silver. — A man made a fire to cook his food and protect himself
from the cold, near the aite of Catorce,^ in Mexico, and in the
morning found silver shining in the a«bes. This was in 1775^
* T. Reunert, " Diamond Uintng at the Cape," Official Handbook to the
Coloaiol Exhibition. £R*tart/, Prodwitioni, and BrtottT«u of tA« Cap* of
Good Hopt. Cape Town, 18S6, p. 17S.
t Wincbell, TaientietkAnKual Report of the Oed. and Nat. HiU. Smrot^tf
Mmneiata.p. 157. Miaaeapolia, 1893.
t fSlalUqiie de Vlndiutrie MintraU en France pour Vannie 1886. Paris,
18S8, p. 25a.
% Ledoiuc, " The Phosphate Beda of Florida," Eitg. Mia. Jonr., vol. slix.
(1890). P- 176-
II Beoksr, '> Qeoloey of the Qnloksilver Deposits of the PaciBc Slope,"
Monoarapht oflhe U.S. Ged. Survey, vol xiii. p. lu. WuhiDgton, t8S8.
1; Chism, "The Catorce Mining District," Eng. 31in. Jour., vol, xlvSi
(1889), p. 340.
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PROSPECTING. 95
and three years later another man pulled up a bush to throw
upon his fire, and found native silver in the roots. Mining soon
began, and between 1779 and i8iz the district 3^elded ore woi-th
from thirty to forty milhon pounds sterling. Tradition relates
that the famous silver minee of Potosi, in Bolivia, were dis-
covered in a similar manner in 1538, by the accidental displace-
ment of a bosh which had small lumps of native silver among the
roots.
Tlie existence of silver in the Province of Famatina, in the
Ai'gentine Republic,* was made known by a pure accident. Leita
and Echavarria were making a journey, in 1 8 1 1 , across the Andes,
and during a terrible storm, took refuge in a cave, and there
passed the night. In the morning they found that the stones
they had put round the fire at night were white, and on further
examination silver was plainly to be seen in them.
Adventitioiu Finds. — Search for one mineral often leads to
the discovery of another. The working of veins for tin ore has
I'evealed the presence of the decomposed granite which furnishes
china clay.
The finders of the Comstockt lode worked it at first for gold,
being quite ignorant of the presence of rich silver ore.
In the winter of 1858-59, some prospectors washed a panful of
earth from a broad-topped mound which one of them bad
noticed previously. This gave gold to the value of fifteen cente,
a high average retom. They then noticed a gopher bole in the
mound, and took up the earth which had been thrown up. This
they washed, with satisfactory results, and at once st^ed out
claims. Another part of the lode was discovered by some other
prospectors, who had dug a hole in order to make a little reservoir
for water. They chanced to wash some of the earth, and to their
BiH'pi'ise found it rich in gold. The upper part {back) of the lode
was then worked for this metal. They threw away bits of a black
rock which they found mixed with the earth and yellow sand,
and when, at a depth of 3 or 4 feet, they came upon a vein of the
black mineral, they had not the least idea that it was valuable.
Pieces, however, were carried away by curious visitors, and one
was given to Mr. Melville Attwood for assay. Ho discovered
that it was worth 83,000 per ton for silver and 8876 for gold.
The black mineral was sulphide of silver, and the yellow sand
proved to be the chloride. The working of the Comstock
lode for ulver dates from this discovery, which was in June 1859.
There are reasons for supposing that the original discoverers
of the Comstock lode were two brothers named Grosh who had
found a rich vein of silver in 1856. But one brother died from
* Hoskold, La RipubUijve Argentine, p. 19,
t Lord, "Comatock Mining and Miners," Monographi of the U,i{. Oeol.
Sun-eji. *ol- iv. pp. 34-55.
i (Jp.cii. pp. 27-31.
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pfi ORE AND STONE-MINING.
the effecte of & slight accident, and the other sood after succumbed
under the hardships he had uiider|[one in croeaiiig the snowa of
the Sierras in December 1857. The knowledge of this vein was
then loat for a time.
In 1S85* Home natiTes or Spaniards took to M. Baftide speci-
mens of what thej thought was calamine from the top of Djebel
Toumiu-Kebir, Department of Gran, Algeria. It turned out to
be phosphate of lime.
When boring for rock salt in 1839 near Staesfurt,t the
PrusBian Government found brine with chloride of magnesium
and chloride of potassium. Later, in 1852, they sank two shafts
throngh the beds containing these minerals, without in any way
recognising their value, in order to work the rock-salt underneath.
Howerer, it was not long before this mistake was corrected, and
the potassium salts soon became the main object of the mining.
The Bub-wealden bore-bole near Battle, wbicb was put down
for general information concerning the underlying strata, met
unexpectedly with a bed of gypsum, which is now re^alarly
mined.
The bed of salt in the Cleveland district was discorered in 1863
by a boring made for the purpose of getting water. The total area
now proved is 20 square nules ; and if the appro^dmate average
thickness of the bed is taken at only 90 feet, it may be estimated
to contain 115,300,000 tons of salt per square mile.?
A borehole was put down in Louisiana near liike Oharles on
the New Orleans-Tesas Bailway in search of petrdeum,§ and a
rich bed of sulphur-bearing rock, 100 feet (30 m.) thick, was
pierced unexpectedly. Owing to the watery nature of some rf
the strata by which it is overlain, it has not yet been worked.
According to a statement issued by theBroken Hill Proprietary
Company, l2mited,H the original claims of this productive sUver
mine were pegged off under the impression that the outcrop was
that of a tin lode.
The Sulphur Bankl[ in California was originally worked for
sulphur, and the fact of there being quidialver was long
unsuspected.
Instances of valuable minerals passing unrecognised are
common.
It is related that the original proprietor of the site of Mount
* StatutiquedePIndiulrieminiraU «n JfYanee pour I'lmtUe 1886. Paris,
1888, p. 285.
t ^Arer zum vUrUn t^gtnuintn Devtsehen Bergmanntiag. iSSg. Balls
a.d. Saale, iSSg, p. uzili.
t Uarley, '* On the CleTcland and South Dorbam Salt lDdnBti7," TVant.
Fed. In*t. M.E., VOL i. (1889-go), p. 341.
9 Rimila dd Servisio Minerarw, 1S88, p. clzzziii.
J Btvort and ^atement of Aftoanti for Balf-ytar ending 2fovember 30,
1B86, Melbonnie, Victoria, 1886, p. 57.
^ Becker, up, at. p. 10.
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PROSPECTING. 97
Morgan gold* mine used to sell some of the auriferous stone,
which resembles pumice, as hearthstone for cleaning doontepa.
Qeaiogr u b G-nide to HineralB.— A knowledge of
geology will often serve to guide the miner. Coal has heen
diM»vered in the sottth-east of England bjr very oaref ul reasoning,
based npon the geological stmoture of South Walee and Somer-
setshire on the west and that of Northern France and Belgiqm on
the east.
M. Meugy,t Inspector- General qf Mines, bearing of the dis-
covery of phosphate of lime in the Lower Qreensond of England,
concluded that similar deposits might occur in the Cretaceous
rocks of France. Search waa made, and valuable deposits were
found in 1853.
Geology also affords the miner aid hy enabling him to identify
certain horizons in stratified rocks by their foesus. The valuable
bed itaelf may not always be foeailiferous, but definite horlEOna
above or below it may be recognisable, and so guide the miner in
his explorations.
ABBOOiated Hiaerals. — The existence of valuable minerals may
be suspected from meeting with some of their common associates,
and, even for the sake of its importance to the prospector, the
subject of the parageneeis of minerals deserves careful study.
The facts are specially marked in the case of tin ore. Oassit-
erite is usually associated with minerals containing boron and
fluorine, such as tourmaline, topaz, fluor-spar and litbia mica,
and also with wolfram, chlorite, and arseniail pyrites ; masses of
magnetic iron ore are frequently accompanied by rocks containing
garnets, hornblende, and epidote.
Zinc blende is a common hanger-on of galena, which likewise
often has barytes in its train. Oalena invariably contains silver,
and frequently enough to enhance its value.
- The associates of gold in quartz veins are various metallic
sulphides, such as iron pyrites, magnetic pjnitee, copper pyrites,
mi^iickel, galena, zinc blende, stibuite, tettadjrmite, and bis-
muthine.
Salt is accompanied by gypsum and anhydrit«, and frequently
has its habitat in red rocks. Mottura explains this by pointing
ont that when sea water is evaporated, the first precipitate is oxide
of iron, that gypaum crystaUiBes out next, and lat«r the sodic
chloride.
BUBFAOS IZTDICATIOnS. — The indications which guide
the prospector are precisely those upon which the geological sur-
veyor depends in making his maps, viz., form of the ground, colour,
nid^ure of the decomposed outcrop, ordinary springs, mineral
springs, indicative plants, altered vegetation, burrows of animals,
(dd workings, slag heaps, ruins, names cS places and old records.
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98 ORE AND STONE-MINING.
Form of the Qronud. — If the valiuible mineral is harder or
softer than the surrounding rocks, it will affect tbe maimer in
which the surface is sculpti^ed by atmospheric agencies. Hard
rocks will project in some way, soft ones will be cut into hollows,
especially if they are impermeable. The outcrop of a hard bed will
be denoted by a steep face or escarpment, and unyielding mineral
veins project above the surface in the form of huge crags (Fig. 89).
In parts of our country, these out-
Fio. 89. crops have been worked away and
are no longer apparent ; but lode-
. quartz blanched by weathering may
' often be seen standing up several
feet above the surface on the Welsh
hills, and the run of some lodes can
be traced for a long distance by a
succes«oa of such outcrops.
In the United States and in Austi-alia this phenomenon is
common.
At the Qreat Western Quicksilver Mine* in California, the
outcrop of the vein appears as a dike over 100 feet wide, and
having precipitous sides in places 75 feet high.
Some of the silver veins of Butte, Montana, crop out, according
to vom Rath,t as great wall-like ridges of brown and black rock,
which is quartz containing the oxides of iron and manganese ; the
Rainbow lode stood up 30 feet above the surface.
The Broken Hill lode at Silverton, New South Wales, was
traceable for fourteen miles by the outcrop of huge black crags
oonoating of ferruginous quarts, brown ironstone, pyrolusite and
other minerals, which in places rose to a height of 50 feet above
the ground, and were 10 to 120 feet wide.
Speaking of the outcrops of gold veins of the Hodgldnson gold-
field of Queensland, Mr. R. L. Jack,^ tbe government geologist,
says, " they can be followed from hill top to hill top, forming at
times insurmountable walls a hundred feet high ; as, for example,
in the peaks west of Mount Tenison Woods. In other places
denudation has left their remains on hill sides or hill tops in the
form of huge cubes of quartzite, from which the surrounding soft
rocks have crumbled away. These cubes stand up weird and
sohtary, like tbe ' perched blocks ' of Alpine and Arctic lands."
The tan lodes of San Jacinto in California ore found in a
country destitute of all v^etation except grass, and their black
outcrops are said to be unusually distinct.§
* LatheiWagoner, "The Geology of the QnioksIlTerHinea of California,"
£nf. Hin. /our., toL zuiv. (1S82), p. 334.
■ + Ntuti JaMrb. /. Minor., GkL, «. PatumUHogit, 1885, p. i6z.
X Bandboat of QuttTuland Oeoiogg. Jxindon, 1886, p. 37.
9 Benedict, "IbeSac JacintoTin Mines," £^n^.Jfia. /our., voL L (1S90),
P- 4S3-
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PROSPECTING. 99
The Great Quartz Vein of Califonua has "a very conspicuous
outcrop, forming the crest of the hilb, so that it caa be readily
seen from a dis^tnoe of several miles."*
The " main reef " of auriferous conglomerate at Johanneehurg,
in the Transvaal, could be traced in places by the pebbles on
the surface.
Soft minerals like clay offer less redstance to rain, flood, and
frost, are more deeply cut into, and give rise to hollows. Thus
the bed of clay known as the Qault, occupies a depression between
the hard and pervious beds of the Chalk and the Lower Greensand.
The presence of the masses of decomposed granite which fqr-
nish china olayt is almost always indicated by a slight depression
of the surface.
The ore bodies in the Sierra Mojada, Mexico, are softer than
the enclodog rocks, which often stand out when the ore has been
worn away by weathering.j
Colour. — Colour is an important factor in the discovery of
mineral deposits. Sometimes the ore itself has a distinct hue.
When Gamier was exploring Kew Caledonia in 1863, he waa
struck by the special green colour of the rocks, and he found
that it was due to coatings, veins, and lumps of a hydrous silicate
of nickel and magnesium, which is now largely worked.
■ Copper minersJs will produce green, blue, and red stains,
which catch the attention very quickly. Iron gives a red or
brown colour, manganese a black ; lead may furnish a grew, a
yellow, or a white coating, cobalt a pink one, whilst cinnabar is
the natural vermilion. Coloured minerals are often used as pig-
ments by savages, and in this way may be brought to the know-
ledge of the e^orer,
Qosaan. — A mineral deposit near the surface is frequently so
altered by atmospheric agencies that it be&rs little resemblance to
the undecomposed bed or vein which will eventually be met with at
a greater depth. A bed of hard shale will crop out at the surface
as a soft clay ; but the most common cases of change are furnished
by the conversion of sulphides into oxides or oxidised compounds,
and the removal of some of the mineral in the form of a soluble
sulphate. Thus iron pyrites, which is such a frequent constituent
of mineral veins, is converted into hydrated oxide of iron, and a
vein, originally consisting of iron pyrites and quarts, becomes a
honeycombed brown and yellow rock, the removal of the iron
pyrites in the form of a soluble sulphate leaving cavities which
are only partly filled up by oxide. The ferruginous solutions
which flow away stain and discolour the adjacent rock.
• Whitney. The Auriftrovt OravtU of the Sierra Nevada of CdUJimiia.
Cambridge, U.S., 1880, p. 46.
t 3. H. Collins, "The HensbaiTow Granite District." Truro, 1878. p. 7.
X Chiun. " Ore Deposits of Sierra Uojada," Traai. Am. Init. M.E., voL
IV. (1886-87), p. 549-
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loo ORE AKD STONE-MINING.
Tbe fermgiDoua outcrop of mineral veias has been notioed ia
all mimng oountriee. In CcHTnwall it ie called gozzan, and this
term has been oarried hy the ubiquitous ComiBh miner to oth^
Engliflh-apeaking countries, though in Australia we hoar of iron-
tbme blowt.
In Oermany the iron ftat gives the proverb —
ti'analated by the late Sir Warington timyth as follows —
In EVance the cAapeau en/er is the equivalent of the German
expression, whilst the Italian miner, ascribing tbe dndery, bumt-
up appearance to the action of firo, calls such ouiorope brueeumi.*
The Spanish term coloradot has refArence to the red tint due to
iron oxtdee. In some parts of South America, such as the
Ai^entiue Republic and Bolivia, the word pacos is used for the
oxidised ores.
The nature of a gozzan varies naturally very greatly, not only
in different districts, but also in di£l«rant parts of the same lodoi
If the vein originally consisted very largely of iron pyrites, the
gozzan will be mainly ochre and brown iron ore, of t^ in botry-
oidal and stalactitic forms. If quartz was present also, a cellulaTr
dudery, cavernous, ferniginous rock ie tbe result of the atmoe-
pherjc weathering.
Other metallic mioerals will leave their traces. Galena be-
comes changed into anglesite, ceruasite, pyromorphite, and mime-
tite. The sulphides of copper yield native copper, melaconite,
cuprite, malachit«, chessylite, together with phosphates, aneniatea,
and silicate of the metal, and sometimes the ozychloride or ozy-
sulphide. Carbonate of manganese gives rise to black oxides, whilst
argentiferous minemls furnish native silver, kerai^yrite and
embolite.
Gold is unlocked from enveloping sulphides, and specimens of
quartz may be seen from nearly every gold-field in which cubical
cavities, left by the removal of iron pyrites, are partly filled up
with ochre and delicate skeletons of the precious metal. Gold
may exist in combination with other elements and be liberated
by the weathering process.
The depth to which the oxidising and leaching action proceeds
in often considerable. In the Oomstock lode t "the quartz is
reddened aud the iron minerals mora or less oxidised to a depth
of 500 feet, but it is probable that the lower 100 feet ara chiefly
* Zoppettl, ArU Mintraria. Milan, 1S82, p. 85.
t Hague, Mining Indtulnj (f the ^orlieA F»alUl. WashingtOD, 1870^
P7S-
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PROSPECTING. loi
«obnirod by the percol&tion of the surface wators." Sometimes
there is a Bb&rplme of demarcniioD, sometimes a gradual passa^
between the gouaa and the sulphides.
In the eectionit of a mioei-al veto, Figs. 90 and 91, A, is the
yonon, showing itself occasionaUy by rough crafts at the surface ;
C, represents the undecomposed sulphides, and B is an interme-
diate Eone where the process of alteration is incomplete. At
Huanchaca silver mine, Boli\ia, the oxidised ores near the sur-
face are called paco*, the transition osysulphides miUatot, whilst
the oncbauged sulphides are known as mHaiee frim. In the
loDgitudinal section, Fig. 91, the alteration is shown as ceasing
Fio. 9a Fig 91
soon after the level of the bottom of the valley is reached, that
is to say when the water no longer has an easy exit ; but dr>
cumatances may bring about a system of circulation causing the
rainwater to penetrate below this level, and then the goszan will
naturally extend to a greater depth.
GoEsan is important to the miner not only becauae it is an
indication of a lode, but also because the ore is sometimes more
valuable from the decomposition of the sulphides. This is
specially the case with gold and silver. Gold, as already explained,
is Ket free from a tight covering of pyrites, or possibly from a stnte
of ccmbination with some other element, and can now be easily
caught by quicksilver. The miner speaks of the ore as " free-
milling " on this account. Silver, when brought into the native
etate, or converted into chloride, is Ukewise readily extracted by
amalgamation.
In the case of argentiferous lead veins, chloride of silver mixed
with carbonate of lead and oxide of iron is more acceptable to
the smelter than a complex mass of metallic sulphides. The
removal of zinc blende by atmospheric agencies, no doubt through
its ooaverdon into a soluble sulphate, is of much importance ;
iat the ore is thus freed from an ingredient which gives trouble
in ttie lead furnaces, and which canuot be eatibfactorily separated
mechanically when very intimately mixed with galena, iron
pyrites and other sulphides. Furthermore the removal of some
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roa ORE AND STONE-MINISG.
of the heavy worthlesa ingrodiente, whilst the sUvm- remains
fix«d as ins^uble chloride, raieee the tuDour of the ore in
the pi-edous metKl. Lastly, the upper parts of the vem are
more cheaply worked from their softoeeB, and the small ooet
of pumping and winding. Under these circumfitanoes the fact
of a mine sometimes becoming less profitable, or wholly un-
profitable, when the zone of sulphides is reached will es^y be
underst«od.
These points must not fail to be considered by the miner ; he
must recollect that the zone of the oxidised ores will be succeeded
by sulphides, more costly to work, and sometimes requiring
totally difTerent treatment.
Qcrazans should be carefully assayed, especially for diver.
Instances could be given of gozzans baring been stamped and
worked for gold, to the utter neglect of the silver which was by
far the more valuable ingredient.
In Cornwall gozzans rf copper lodes have been worked for tin
ore, which was originally enclosed in or mixed with coppw and
iron pyrites. Owing to its insolubility it resisted the weathering
which carried away the copper and some of the iron in solution.
The Anaconda mine* at Butte, Montana, now famous for its
enormous output of copper, was originally bought as a silver
mine. For a depth of 400 feet the ores contained no notable
quantity of copper ; this metal had been carried off in solution,
whilst the silver, converted into an insoluble chloride, was
rendered proof against any further action of rainwater.
Deposits of cupreous iron pyrites may have the copper and
sulphur so completely removed that the remaining oxide of iron
is worked as an ore of this roetal.f
The iron ores of Bilbao are the decomposed portions of deposits
of the carbonate. The weathering has had two useful effects;
it has raised the percentage of iron, and it has lowered the
amount of sulphur by decomposing the iron pyrites, which occurs
in small quantities in the unaltered ore.
The seams containing native sulphur in Sicily often show no
trace of that element at the surface, as the sulphur- bearing
limestone weathers into a soft, white, grey, or yellowish white,
granular or pulverulent variety of gypsum, called bruealet
by the miners, and considered by them to afford important
indicaticms concerning the bed itself. In this case the sulphur
has gradually become oxidised and has combined with some of
* DDnglas, " Tbe Copper Resonroes of the United States," ZVani . Amer.
Iiut. M.E., Tol. xU. (1890-gi), p. 679.
t Hozham, "The ' Great Gossan Lead ' of Vliglnia,'' Traiu. Amer. latt,
M.E., vol, xii. (1891), p. 134.
X Loreoio Parodi, ^uW atrasiont dtlU> Sdlfo in Sicilln. Florence, 1873,
pp. 7. Z4 ; and L. Baldacol, Detcrizlone geologica delf Jtola di 3ieitia.
Rome. 18S6 p. 106.
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PROBPECTING.
'03
the lime to form a sulphate ; and it is only natural to suppose
that the thicker and the richer tbe oiiginal bed was, the greater
will be the amount of briaeaie produced, and the more apparent
its signs on the Burfaoe.
Each mineral therefore has to be considered separately, and I
may mention a few other special casee.
Yeina of aabeetoe have been discovered by noticing a white
powdery substance in crocks in the rocks, which led to fibrous
asbestos when worked.
Steam-puf& are indicationtt of the small superficial deposits of
sulphur in volcanic districts; and here sight is aided by tJie sense
of smell, for I recollect remarking the odour of sulphuretted
hydrogen long before I rode up to some sulphur banks in
Iceland. In Tuscany the natural steam-pufis which yield bomcic
acid are plainly visible, and bore-holes * are also put down to
produce them artifidally where the rocks are hot at the surface,
and so give hopes of tapmng vapour at a shallow depth.
Some of the successful bore-holes for carbonic acid gas in the
Eifel, Gennany, were planned on account of natural emanadons
of the gas in the immediate vicinity.
Attention has been directed to petroleum by a layer or an
iridescent film of the oil upon pools of water, and the odour is
sometimes perceptible for a long distance. 0£F Baku, on the
Caspian, even the sea is sometimes covered with an oily film of
petroleum.
Brine springs point to salt, chalybeate aprings to iron, but not
necessarily to deposits of any commercial value; the same may
be said of water impregnated with sulphuretted hydrogen as an
indication of native sulphur. Springs of ordinary water may be
expected to appear where a pervious bed rests upon an imper-
vious one, so that the outcrop of a bed of clay under sandstone
is often denoted by a snccesuon of springs, in addition to the
change in the form of the ground.
Even when the valuable deposit presents no striking outcrop,
it may be followed by observiiw some more marked attendant.
Thus the " red bar "f of the Johannesburg district, is a bed of
dark red slate which is seen protruding above the surface, a little
to the north of the gold-bearing conglomerate, for a distance of
20 miles along the strike.
In California + a dark opahne or choloedonic rock, known to
the miners as " quicksilver rock," is associated with the deposits
of cinnabar, and owing to its comparative hardness stands out
sometimes as a projecting outcrop.
IndiofttiTe Plants. — As pUnts derive part of their nourish-
Uonogra^ o/lht bS, Q«A. Hurveij, -vol. :
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104 ORE AND STONE-MINING.
m«nt from their roots, and as different [4ants require diilerwit
foods, it IB only natural to suppose ihat a change of soil causes a
change in the vegetation.
Beds of porous limestone let the rain so^ down at onoe, the soil
is shallow, and the foothold for trees is not so good ss in the
case of days. Thus the chalk hills are bare, and the Weald clay
is the home of the oak from a mechanical reason, in addition to
the chemical one of nourishment.
Clays will retain water and naturally be the habitat of rushes
mud other moisture-loving plants.
The effect of salt in the rocks is especially marked, and
CKtischmann'givee along list of plants which either flourish beet
when getting salt, or cannot exist without it.
The flora of Monte Catini,t in the province of Liu^, well
known for its brine baths, resembles that of the coast, although
34 miles away from the nea, and separated from it by the Fisau
Hills.
My friend, Mr. S. Herbert Cox, tells me that the run of the
deposit of alunite which he is working in New South Wales, is
marked hy a lighter green in the colour of the leaves of the
eooalyptuB trees which cover the district. He has also noticed
in New Zealand that the Karaoca trees growing upon limeettme
hare darker leavee than those growing upon slate. A band of
limestone can be traced in this way.
The subject of indicative plants is dealt with in an interesting
paper by Raymond,! who gives some additional details concerning
the caLuuine pansyof Rhenish Prussia, mentioned by Qatiecbmanu.
This pan^, called by botanists Viola calaminaria, is peculiar to
the calamine-bearing hills near Aix-la-Cbapelle, and in West-
phalia. The blossoms are almost always yellow ; but on
tbe borders of the sine regions some are light violet, or bluish,
or mixed yellow and Uue, and are suppoeed to be hybrids
between V. ealaminaria and the ordinary mid pansy, V. tricolors
Analysis has revealed the presence of zinc in the plant
and in the sap. This plant is said to have been recognised at
Horn Silver Mine in Utah, the ore of which contains zinc
blende.
The lead plant, Amorpha eaneaeent, Nutt., is a low shnib, i ft.
to 3 ft. high, whitened with hoary down. Hie plant is moat
abundant m Michigan, Wisconsin, and IlUnms, and miners
believe that it flourishes best where lead ore exists in the soil.
Dr. F. Stapff found that prospectors tor phosphorite, in
BLetremadura were guided by a. creeping plant wUh bell-shaped
flowers, Convoitndut aiihcMidet ; m Mgntana .the Srigonum
* Die Auftudmng uwl Unleriudtung mnt LogtritSUejinattboTer if intralle»-
Leipoic, iS66,|). 311.
f Jervis, (Jidda aUt aajne miiurali iPlttdia. Torin, 1868, p. iz.
; ThiM. ^m. Jiul. il.£., VOL xv. (1886-8;), p. 64?.
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PROSPECTING. 105
ooal^oiimn, Natt., is looked up<m as an indication of silver ore in
the vieimty.
*"*—t^^t as Indioatora. — Animaiu also may occasionally
tender services to the prdepector. I have already mentioned the
case of the wombat, by whose burrowa copper was discovered in
South Australia. Prospectors seeding for tin lodes in Yictorui*
have also been guided to saccess by the ore thrown out from
decomposed dykes by this animal. Ledouxt says that a useful
indicatim c£ phoepbate of lime in Florida was furnished by ant-
hills and gopher holes, which showed small whitish grains of the
mineral in the earth,
Qatzschmannt mentions cases of the discoveiy of valuaUe ores
I^ the Bcratcbings of the beaver, the bear, and the marmot, as
wdl as by the wallowing of pigs ; he also brings forward in-
staaoee in which the first indications of mineral weidth wei'e
aflbrded by stones kicked up by a horse, or tossed out by a
boll, or lying in the nest of a vulture, or found in the crop of a
At the Caratal diggings in Yenezuela, a bird called the minero
was thought to mark the site of gold-bearing gravel. I often
heard its notes when passing pits where gold was being obtained,
and it is pcesibls that it preferred certain trees which grew upon
the old alluvia. In fact, as so many animals obtain their food
from special plants, it is evident that the fauna dependent upon the
fltaa most be affected indirectly by the minerals of the soil. The
spedal case of there being more genera and species of snails in a
limestone omntry is acasein point. Lastly, the tracks of animals
may lead to salt springs which they frequent.
ShcMding. — The prospector seeks for natural sections of the
rocks snch as occur in difis, or in river valleys and their tributaiy
gollies and gorges. He examines the materials constituting the
rivOT .beds, especially when the water is low in the dry season,
.ottvt digging op and washing portions in a pan or in a batea, in
wder to ascertAJn whether they contain traces of the heavy ores
«r metals.
If, while prospecting in a v&Iley, he discovers stones that have
4liia appearam-e of having once belonged to veins or other valuable
deposita, he endeavours to trace them to their source, and is,
prahape, rewarded by finding similar fragments, bat lees water-
mrh, as he goes up the Bti«am. Further on he may come upon
lawe blocks of veinstutf lying about, and finally find the veins
laid bare in a gorge, or at the bottom of a brook, or possibly pro-
.jecting above the biM in the form of huge crags of quarts m the
manner already described.
' Victoria, Jtiporf aadSUUUlic* of the Mining Dtparlmtttt for the Quarter
(wfed Jfarc&3i, 1890,1). 15. Melbonms, 11190.
' f A, K. I«doux, " The Phosphate Beds of Florida," JCag. Jlln. Jour.,
Tid.xlix. Feb. 1890^ p. 176. , iOp.cil.p.iii.
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io6 ORE AND STONE-MINING.
Loose pieces of veinstuff found lying about on the surface are
known in Gomwa]l as ^hoad-tl&nea ; and ahoading is the tenn
given to tiie process of tracking them to the parent lode.
If the proepector has ascertained the ezintence of a lode by
shoad- stones, and has some idea of the position of the outcrop
which lies concealed under the soil, he proceeds to dig trenches
across the presumed line of strike, until he hits upon the back
of the lode. When the covering of soil is too deep for trenching,
a little shaft is sunk, and a tunnel is driven out at right angles
to the supposed coui'se of the vein.
Loaming in Australia corresponds to shoading. The prmpector
washes earth from the base and slope of a hill till the specks
of gold are pretty frequent, and then endeavours to trace the gold
uphill to the reef that furnished it. When he can no longer get
gold by washing he concludes he has gone past the outcrop of the
reef, and he proceeds to seai'ch for it by trenching. Beefo have
been discovered in this way which showed no si^aoe indication
whatever.*
Hnshing.'t' — Hushing consists in causing a stream of water
to rush down a hillside, and cut a ditch through the soil, which
will lay bare the outcrops of veins, if any exist. A reservoir is
made at some suitable spot on the high ground, and a shallow
gutter is dug down the slope along the line which it is pro-
posed the stream should take. The wat«r is allowed to run down
gently at first, and then as a torrent, which sooura out a trench
to the solid rock. An examination of the trench and of the stones
washed out of it may result in the discoveiy of a vein.
Fiexoing. — In some special cases when the mineral lies veiy
near the surface, and is either harder or softer than the surround-
ing rock, the searcher makes use of a sharp pointed steel rod,
which he thrusts into the ground. The welt-known French l
burr-stones, lying in soft sand and clay at a depth of lo to i8
feet, are found in this way ; whilst in the Isle of Man superficial
pockets of umber in the Osj-boniferous limestone are detected by
the ease with which the rod runs down.
Kauri gum, a semi-fossil resin of New Zealand, which occurs in
lumps of about the size of a hen's era; a few inches below the sur*
face in the high ground, and a few feet in the swamps, is sought
for by a similar tool.
Mr. lawn informs me that in the Fumess district a pointed
iron rod is occasionally used in searching for shallow depodte
of hematite, lying within 6 or 8 feet of the surface. The miner
examinee the point of the rod after thrusting it through the thin
• "The Gold-fields o£ Victoria," ^<pi>rt»i>/(*« Mining Btgatrarg for the
QuartfT ended JUarch 31, 1888. Melbounie, 18SS, p. 68.
t Williams, Katurai Hatorg 0/ the Mineral Kingdom. Edinburgh, 1789,
vol. i. p. 370.
t Callon, Lectum* on Mining. IxtDdon, 1881, vol. ii. p. 41.
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PROSPECTIXO, 107
coTerisg of aoil, and if he finds it to be red, he coodades that
there is iron ore underneath. If the indications are sufficient,
he sinks a Jittle pit and b^ns to work the ore.
The valuable bed of phospbatic nodules in Suuth Carolina ' is
much harder than the overlying sand and cU; ; the proepector
carrying a steel rod yrarks it down, until he meete with the resist-
ing stratum. He notes the depth, which is under t$ feet, as
no phosphate is at present worked deeper than that, and after
walking on 100 feet further forces the rod down again. By
thrusting down the rod at regular intervak in this way, and
noting the reeults, be obtainsa general idea of the lie of the phos-
phate bed, and proceeds to make a more minute examination by
sinking exploratory pits, 10 feet by 5 feet, at intervals of 500
feet. The phosphate rock laid Iwire is takeu out, carefully
sampled and analysed, and in this way a very fair estimate can be
made of the yield of a given area.
The process of testing a bed of mineral by pits is sometimes
carried ont on a very extensive scale. According to Winchell
$60,000 have been spent in mere explorations at the Biwabik
Ii-on ^ne,t in the Meeabi Range, Minnesota ; but in this case the
pit« were practically small shafts, many of which exceeded 100
feet in depth.
ZiOde-lights. — Appearances of flame above mineral veins are
said to have been seen, and at all events are sufficiently well estab-
lished to have received a special name, " lode-lights," in Cornwall.
It is possible that a will-of-the-nisp (phosphoretted hydrogen) may
hare been produced occasionally by the action of organic matter
and water upon phosphates, which are so common in the upper
parts of mineral veins.
Marsh-gas is known in the workings of some lead lodes, and
may have occasionally issued in sufficient quantity to produce
flame when ignited accidentally.
Altered Vegetation and other indications.— One hears of
differences in the appearance of the vegetation along the line of
mineral deposits, ai places where the snow will not lie in the
winter, and of vapours hanging over the ground. Though some
writers refuse to put any value on these indications, they should
not be entirely overlooked, because the outcrop of a lode, of
different nature and texture to the surrounding rocks, may readily
cause the phenomena just mentioned. One need only look at the
rubbish-heaps of some mines, especially those yielding pyrites,
which remain year after year bare and barren, t« understand the
blighting and withering action of the products of decomposition of
some minerals upon vegetation. It ia only natural to suppose that
* Wjatt, ThePkomhalaofAnteriea. New York, 1891, p.49-
■f '•Tbt Biwabik Miite," Traiu. Amer. fail. M.E., vol. xxi., 1892-3,
p. 951 ; and Qtol. aitd Nat. Hat. Survey of Miniietota. T«)e>U\elh Ani^
Jtep.f0T tht j/tar 1S91. UluDeapoUs, 189J, p. 156.
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io8 ORE AND STONE-MINING.
graae would grow lees luxuriantly upon a wide pyritous vein than
upon adjacent alftte, and that & decided ntreak of altered colour
and growth would be vieible upon the turf.
A very Bunple experiment will convince the student more
readily than tbe mere statement. Spread a thin layer of earth
upon a tray, and imitate tbe outcrop of a lode by scraping away
some of the earth and re-placing it by powdered iron pyrites or
marcasite. Now scatter mnstu^ seed over tbe surface, an4
water frequently. In the coarse of a few days there will be a
crop of mustard on the earth, but tbe track of tbe nyrites will be
marked by a bare streak on which tbe seeds have been killed by
sulphate of iron formed" by its decomposition.
The rapid disappearance of snow on the outcrop of a lode has
been noticed at Ducktown Mine, Tennessee,* among other places.
Tbe oxidation going on in a pyritous lode near the surface must
produce a certain amount of beat, which would make the outcrop of
a lode w^frmer than tbe adjacent ruck ; but one need not have
recourse to this hypotbeeis in order to account for phenomena of
this kind. Mineral veins are often channels along which under-
ground wat«rs drculate ; this water may come near to the surface
in places, or even issue forth as u spriuKi and the proximity of
tbe comparatively warm water may keep tjie outcrop warm enough
not to freeze. In a porous cavernous gozzan it is easy to imagine
the existence of slow currents of tbe air which would have the
same effect.
The fact of a vein often being a channel of water will also
explain the risiug of vapours from lodes under certain favourable
<nnditions of the atmoephere.
Where the surface is cultivated and the natural springs are
tapped by adit levels or other mine workings, these appearances
cannot be looked for to aoy great extent ; and it b not unlikely
that the old miners, who have banded as down traditions con-
cerning the signs of mineral veins, were keener observers of
nature than some of theii' successors, just aa tbe savage may be
guided by marks which do not catdi the eye of tbe civilised
.traveller.
Old Workings, Blag Heaps, Kuins. — Signs of old woridngK,
such as pits and rubbosh-heaps, often tell useful tales. When
workings wtt« shallow, miners put down shafts inclose proximity,
and tbe line of a series of shafts and rubbisb-beaps will give a
fairly correct idea of the strike of a lode. Tbe rubbisb-beaps
will show what was tbe ore worked, and with what it was asso-
d&ted.
It even happens that mining refuse, thrown away as worthless
in the days when dressing appliances were crude and rough, will
pay for being worked over again. On the other hand it is not safe
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PROSPECTING.
105
to conclude that, beuaiise it paid to work & miae some centuries
ago, the same ore will yield a greater profit or even be worth
working nowadays. The change in the value of the precious
metals, and the change in the remuneration of the labourer, moat
be duly weighed before a decision can be arrived at,
It is important to ascertain why the old mines were abandoned.
If no good reason, such as a sadden inrush of water, or the break-
ing out of a great war, for instance, can he assigned for the stop-
page, it is usually safe to assume that no great riches have been
left in sight ; statements to the conttnry must be very carefully
sifted.
Minerals that were at one time worthless or even regarded ax
obnoxious, such as nickel and cobalt oree, or zinc blende, become
valuable by the discovery of new or improved processes of manu-
facture or smelting. An instance of this Idnd has occurred quite
lately. Some forty years ago the outcrops of beds of impure car-
bonate of manganese in North Wales were worked for the black
oxtdee, the gozzans, in fact, which had been produced 1:^ the
weathering of the deposit near the surface. The undecomposed
carbonate was at that time of no value and was carefully separated
by cobbing and reject«d ; and the workings had to be abcuidoned
when the black oxide diminished in quantity at a shallow depth,
and was replaced by unweathered ore. Owing to the use of f erro-
maogauese in making steel, the carbonate can now be utilised,
and the ore is regnlariy mined and sent to the blast furnaces to
be smelted with iron ore.
On the other hand the discovery of a new process may be the
means of canning a mine to be unprofitable. The discovery br
Weldon of a method of regenerating the oxide of manganese used
in making bleaching powder, seriously afiected manganese mining
by lessening the demand for the ore.
Old mme plans, reports, and deeds should be consulted when
available ; and information should be sought from official geological
surveys and mining records when they exist, as they do in this
country. A prospector told me a few years ago that he missed
securing some manganese properties in North Wales, from not
being aware that a government geological map of the district had
been published, showing some of the outcrops of the manganiferous
bed.
Slag heaps afibrd indirect evidence of mining, and like old
rubbish-heaps may occasionally be worth smelting. The most
notable instance of late years has been the profitable treatment
of such heaps at Laurium, in Greece.
Ruinedcities,orotherindicationsof a country having been more
thickly populated, are sometimes adduced as proofs of its mineral
wealth. Where it is possible to show, from remains found in the
towns or encampments, that the inhabitants, were engaged in
mining or smelting operations, the prospector. may fairly lay stress
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no ORE AND STONE-MINING.
upon evidence of thie kind. It has often been supposed that gome
of the old entrenchmente in Cornwall were made for the protec-
tion of diggers or smelters of alluvial tin ore ; and after the careful
explorations of Mr. Theodore Bent at Zimbabwe, in Maahonaland,
moBt persons will be disposed to agree with him that this old city
and its fellows owed their existence to gold mining.
ITamaB of Plaom. — Local ntunes may sometimes supply in-
formation, either hy denoting some natural feature txmnected with
the deposit, or by recording in some way the existence of mine work-
ings. Th^ will be found in all languages, and I need only give afew
instances. " Cae Coch," near Trefriw, in Carnarvonshire, means
the " red field," from the ohalybeate springs, which are due to the
existence of a bed of iron pyrites now being worlrod, " Graig
Goch " or " red rock," a name which is not uncommon for mines
in Wales, denotes no doubt that the vein was discovered by a red
ferruginous outcrop, and so does the name " Fron Goch " or " red
breast." Bed Mountain, near Birmingham, Alabama, owes its
name to the outcrop of an important bed of iron ore. " Glosdir,"
meaning " blue ground," is the name of a copper mine in North
Wales. I cannot help suspecting that the locality was so called
in consequence of the blue colour given to rocks or stones by
coppery minerals derived from chalcopyrite near the surface.
" Balmynhir " or the " diggings at the long stone," denotes work-
ings for tin in the neighbourhood of a " menhir " or erect stone in
Cornwall. Sometimes the substance is named, as in the words
Tincroft, Stahlberg (steel mountain), Porto Ferraio (iron port) in
Elba, Gebel Zeit (oil mountain) on the shores of the Bed Sea,
Yenang-jraung (Creek of oil), the site of the petroleum wells in
Barmui. The names LeadhJills (Scotland), Bleiberg (Germany),
and Gebel-el-Kohol (Tunis), all have the same signification, and
have been given from the existence of workings for lead ore.
" Al maden" means " the mine," and turning from Spain to our
own country, we find " Miners," near Wrexham, wiUi a similar
signification given in this case by the Romans, instead of the
Moors. The Smoky Mountains,* in North Carolina, were called
by the Indians " Unaka," from their word " Unakeh," meaning
"white," because they obtained white kaolin from them.
Salt is indicated by the prefix " Sal," " Salz," or its equivalent
" Hall," in numerous names of places.
The Gorman word for miner, "Bergmann" — i.e., mountain
man or highhmder — reminds us that the old ore-seekers were
hilbnen, and found their treasures among the mountains, and we
constantly find the word " Berg " (mountain), or its equivalent in
other languages, forming part of the names of mines or mining
towns. Schneeberg, Marienberg, Freiberg, in Saxony, are
instances, and of recent date we have Mount Morgan in Queens-
■ W. B. Phillips, " Miea HlniiiK in North Carolina," Eng. ifin. Journ.,
voLilv. (I8S8), p. 398.
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PROSPECTING. Ill
luid, and Broken Hill in New South Wales. In the list of
copper mines of South Aoetealia* I find no less than twenty-six
Q&mee of minee beginning with " Mount," in addition to others
coDtaining the word " hill " or " knob."
Other n&mea refer to mining or smelting operations. Ihe
Tillage of Pestarena, near Honte Boea, was evidently so called
from the crushing of gold ore in the days of the Bomans.
" Cinderford," in the Forest of Dean, points to old heaps of iron
stag, and such a name as " hammer pond," in the Weald of Kent
and Sussex, likewise tells us of iron worldng in days gone by. But
no streea should be laid upon names ; they afibrd at most an indica-
tion of the existence of a mineral, without any evidenoe of its
value at the present day.
Divining Bod. — B^ef in the divining rod, or dowsing rod,
has not died out completely even in Cornwall, where one stilt
Fio. 93.
meets with educated persons who profess to be able to discover
mineTal veins by the dipping down of the forked twig when they
walk acnes them.
r^. 93, reduced from Agrii]ola,f shows old German miners
aean^ng for veins with the rod.
Dipping Hfiedle. — In the special case of magnetic iron we have
a safer guide. In Sweden a magnet, suspended so that it can dip
"A Record of the Mines of SontL Australia."
p. z8 ; and Broagh. " Cantor Lectnrea on
I, vol. xl. (1893), p. S03.
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iiz ORE AND STONE-MIKING.
in an; direction, is regularly used for tradog maaam of magnietic
iron ore, even when tmnoealed by some thickneae of drift or some
depth of vater; when the lakes are
Fiu. 93. frozen over in winter, this kind of pro-
Epecting is easy.
The miner carries his compass care-,
fully over the ground, and on approach-
ing magnetic ore the needle dips towards
it ; the amount of dip increases, until at
last, when standing directly over the
dep^t, the needle becomes vertical, and
remains so as long as there is a strong
mass of ore underneath it. The boun-
dary of the deposit can thus be laid down
on a map with some d^ree of accuracy.
Themodi£catioQof theSwedishdippiog
needle shown in Fig. 93, borrowed from
, Brough,* has been adopted in the United
StatM. Improved methods devised by
I Brooks, Thal^n, and Tiberg are described
by the same author.
QnallflOBtloiu of the Frospeotor.
—From the above obeervations it will be
seen that the miner is greatly aided in his
search by a variety of natural indications ;
but in a new and unsettled country the physical difficulties of
travel are often so great, that strength of body and the capability
of supporting fatigue and hardshipe become some of the most
important qualifications of the prospector. He should have
a general knowledge of geology, aud understand mineralogy
sufficiently to recognise iJl the common and valuable mineraJs
and their ordinary associates, and to confirm his opinion by
simple tests. The pick, shovel, and pan should be handled with
ease, as well as the rifle and the gun. Keen and good eyesight is
a nne qvd non/ a myopic prospector would ftul to recognise
natural features, and a colour-blind person would not be struck
by important differences of tint.
The mode of discovering minerals by boring is a subject of so
much importance that it requires a sepqrate chapter.
• A TVeatitt on Mi-at Stirvryi'ig. London, 1891, p. afii.
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( "3 )
CHAPTER III.
Uses of boie-boles. — Uetbods o( boring holes: — I. Boring; by Totation ;
AngBT 1 Diamond ijcllle.— II. Boring bj percussioa with lodsj Lvn
rods, wooden rods; Driren wells. — III. Boring bj percussion witb
rope; American system; Matber and Piatt's system. — Barfejiag
bore-boles.
Tha uses of bore-holea ore numerous :
of working it if possible.
a. To ascertain tbe nature of tbe subjacent rocks for engineering pur-
poses, sncb as their suitability for railways, canals, locks, sewers,
or foandatione of bridges and buildings.
3. To obtain liquids, soch as ordinary water, mineral water, brine 01
petroleum, which either rise to tbe surface, or have to bis pumped
up from a certain depth.
4. To make absorbeut wells in dry and porous strata.
5. To obtain gases, such as natural inBammabte gas, carbonto acid gas,
or vapouis containing boric acid.
6. To drain oS gaa from rocks, and water or gas from mine workings.
7. To make passages for Donveying power mto undergronnd workings
by steam, water, wire-ropes, or eleotrioitj.
& To put signal wires or speaking tubes into Dudergroand workings.
9. To introduce oement into unsonnd fonndatloas in order to strengthen
thcM, uid also into mine-workings in order to dam back water.
10. To ^nk holes for lightning conductors, hoose-lilts, or piles.
11. To sink mine shafts.
The methods of boring holes for these parposea are :
I. By rotation.
II. By pennsslon, witb rods.
III. By percussion, with ropes.
I. BOBING BT EOTATIOIT.— Auger.— Soft rocks, such
as clay, soft shale, sandy clay, and saod can be bored by an
open auger (Fig. 94)1 like the well-known carpenter's tool.
The mode of working consists* in twisting the tool round by
means of a cross-head or spanner, and lengthening it as the
hole is deepened. The lengutening rods are made of wood or
iron, the iron ones being i^ inch gas-pipe, with screwed pin
• Darley, " Aitesiaa Wells," EngiruarUg, toI, xxxiz. (1885), p. 683.
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114
ORE AND STONE-MINING.
and box ends welded on. Even when iron rods are used, some
made of pine, 4 inches by 4 inches, are added in order to t^e
off part of the heavy weight by their buoyancy in water. For
raising the rods an iron or wooden derrick is employed, such as is
Fro. 94.
FlQ. 95.
ahovn in the figure 95. It is 30 feet high, bo as to give room for
pulling up a rod of the usual length of 35 feet, which is drawn
up by means of a orab-winch with a ij inch iron or steel wire
rope. The winch is worked by hand or horee-power as required.
^Hie top rod is made of square iron, and the cross-head or capstan
spanner can be fixed to it at the height most convenient for
handliiig.
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ii6
ORE AND STONE-MINING.
Fio. 97.
The process of boring consists in turning the rod by two
men. at the capstan until the working tool has filled itself; it has
then to be drawn up and emptied. In drawing up, each rod baa
to be unscrewed and taken ofT, and the process is reversed when
the tool, after having been cleaned out, is again lowered.
In favourable strata holes are bcn«d 400 feet deep at the
rate of 35 feet a day by this method ; it is obvious that, owing to
the time occupied in raising and lowering the rods, tbe first
E:t of the boring is performed at a much greater speed than tbe
t.
In order to obviate the loss of time which ensues in raising and
lowering the rod, for the purpose of extracting the contents of the
auger, a current of water may be sent down through tbe hollow
rod, and madn to ascend in tbe annular space be-
tween it and the side of the hole with sufficient
velocity t^i carry up the debris.
Fig. 96, again borrowed from Darley,* shows
tbe derrick and general arrangement of the
plant : a is the boring rod made of 2I inch {in-
ternal diameter) gas-pipe or lap -welded iron pipe,
in lengths of 25 feet. The separate rods are
joined, as shown in Fig. 97, by screwed spigot
and socket connections which are riveted on.
The short topmost piece of rod h (Fig. 98),
carries the chamber c, at the base of which the
bead of b can revolve freely. On tbe same rod b
is keyed the spur-wheel d. This is actuated by
the pinion e upon tbe vertical shaft /, which re-
ceives its motion from the horizontal shaft h
(Fig, 96), through a belt and the mitre wheels g.
The boring rod is driven at a speed of 80 to
100 revolutions per minute. It is easy to under-
stand from the figure how the rope drums j are
worked from the same shaft h at slow or high
speed by using one or other of the two clutches
upon this shaft. Water is pumped into c by a
hose, descends the rod, and passing through the bit ascends with
the sludge and chips of rocks.
As the bit and rods descend, the carrier under the spur-wheel
d follows them, and also the pinion e, which is loose upon tbe
square shaft/
Fig. 99 represents a favourite form of cutting tool or boring
bit, whi^ begins by making a small hole and then speedily
enlarges it to the full diameter.
As the lining tubes are usually 7 inches in diameter, the
annular space between the tube and the boring rod is large,
* Op. oit. p. 684.
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BOEING. n;
&nd tliis IB diminiahed by adding a lagging of wood (shown in
Rg, 97) for the purpose of inereasing the velocity of the upward
cuirrant and so promoting the discharge of the d^bns.
The rapidity with which some holes are hored by this machinery
is considerable. Mr. Darley mentions that a bole had been bored
Fia. 98.
Fio. 99.
c^^
to the depth of 500 feet, and cased all the way in ii| days,
including the time occupied in putting up the derrick.
Another rotatoiy method for sinking wella or exploring in soft
or moderately bard ground consists in revolving the oamng or
lining tube, which is shod with hard steel teeth,* whilst a stream
of water is forced down through it ; the water ascends in the
narrow annular space between the tube and the sides of the hole.
The core is gradually washed away by the descending current,
and the inventors claim that any clay carried up by the water
forms in time a protecting shell to the sides of the bore-hole,
if composed of reiy loose strata. They even send down clay,
chaff, bran, or cement by the tube for the express purpose of
its making a resisting. lining shelL
In the alluvium of the Mississippi at Kew Orleans a 7-inch
well was bored in this manner 500 feet deep in 48 hours.
For boring boles not exceeding 40 or 50 feet (13 to 15 m.) in depth,
which may be required for geological sui-veya or for investigating
shallow-lying deposits, a convenient portable set of tools has been
arranged by Messrs. Van den Broeck and Butotf It consists of
the following parts : (1) a series of rods 4 feet i inch (I'zs m.)
long, which can be put together by screw joints ; {2) either a
chisel cutter or a twisted auger, for doing the actuaJ baring ; and
(3) a handle which is attached to the topmost rod. As accessory
• Encudopedia of WeS-Sinking Applianca. The Americsn Well Worki,
Aarora, Illinoia, U.S.A., 1S86, p. 183.
+ " Un nonvel appareil, portatit de Bondage pour ri
An temin," BuUeUn Hoe. Beige de Oiulogie, tome ii. (Annte ti
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ii8 ORE AND STONE-MINING.
parts, there are spanners for unscrewing the rods, a key for support-
ing the rods during this operation, and a second handle which cao
be fised on any part of the line of rods if more force is required
tor the work. By a very iDgemons clip, each joint can be so fixed
that it cannot become unscrewed during the proceea of boring.
The diamet«r of the large auger is ij inch (45 mm.) and the
cutting part has two winpa which are of service in penetrat-
ing the ground. The chisel is used for hard seams, such ns
ironstone, grit, and beds containing fossUs or pebbles ; like the
auger, it is i| inch across. The apparatus is very portable,
for no part is more than 4 feet i inch long ; each rod weighs 4*4
lbs. (3 icil.), and the total weight of all the plant required for
making a boring 40 feet deep ie only 64 lbs. (29 kil.).
Diamond Drills. — The most important ]aad of boring by
rotation is done with the diamond drill. The working part of
the drill consists of the so-called crown, which
FiQ. 100. is a short piece of tube made of cast steel, at
one end of which a number of black dia-
monds are fastened into small cavities. The
crown is screwed on to wrought-iron pipes,
which constitute the boring rod. This is
niade to rotate, and the result is that an
annular groove is cut at the bottom of the
hole, leaving a core which often breaks off of
itself, is caught by a little shoulder, and
brought out with the rod (Fig. loo).* In
places where it is not necessary to make any
verification of the rocks travereed, the crown
may be arranged with diamonds in the centre
also, so that the whole of the bottom of the hole is ground away.
The d6bris in either case are washed away by a stream of water,
which is forced down the tube and flows up
Fig. ioi. the sides of the hole.
01n order to prevent capital from being
locked up in a stock of large crowns, Messrs.
Docwra sometimes fix the diamonds in steel
plugs, which will fit holes in any ring. The
diamonds can then easily be taken out of one
crown and placed in another without re-
setting.
The crown represented in Fig. loi was the
largest employed at the deep boring at Northampton. It was
screwed to a tube 30 feet long (Fig. 102), which enabled cores of
almost that length to be cut without withdrawing the tool. The
object of the open sediment-tube above the core-tube was to catch
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Fia. I
Fio. 103.
P
BORING. 119
any coarse particles too heavy to be carried up by the water, as
wul as any frogments falling from the aides of the hole.
Though pieces of the core often broke off of themselves and came
up in the tube, it vas necessary to use the
flxtiactor (Fig. 103) ; it consisted of a ring A,
which was screwed by a few threads to the
core-tube in the place of the crown. On
reaching the bottom of the hole the screw-
ing-up was continued, and the descent of the
portion C gradually forced down six teeth,
such as S, into the position shown by B',
gripping the core tightly. If not broken off
completely by this action, it gave way when
the tube was pulled, and came up inside it.
The " Dauntless" (Fig. 104) is one of the
diamond drills made by the Bullock Manu-
facturing Company, of Chicago, for boring
prospecting holes, and is capable of drilling a
3 -inch hole to a depth of more than zooo
feet, and furnishing cores of i-^gth inch in
diameter. Cores show-
ing visible gold have
lately been brought up
from a hole 2500 feet
deep, bored by one of
these drills near Johan-
nesburg.
The machine is con-
as follows : A
% pair of cylin-
ders, driven by steam
or compressed air, which ^^ _ -m -.
work the bevel wheel
B ify gearing. The feed-screw CO can slide readily up and
down through B ; but as B carries a feather lying in a slot in O,
the latter is driven round when the former rotates. D is the
crown set with diamonds, screwed on to the fiist piece of boring
tube C", attached to 0 by the chuck C. The hose, E, coming
from a special pump, brings in a continuous supply of water
which passeB down C and comes out through D, Y", F", F"',
and G", G", G"', constitute the differential feed-gear for causing
the feed-screw C, and consequently the bit D, to descend as the
hole is deepened.
F', F", and F"' are connected with B so that they revolve when
it does ; G', G", and G'" are loose upon the counter-shaft, but any
one of them can be made fast to it by operating the clutch H.
K is a toothed wheel attached solidly to the bottom of a feed-nut
through whioh 0 passes ; when E. rotates it causes C to ascend or
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120 ORE AND STONE-MIKING.
desoend. L is a wheel equal in size to E, which it drives whea
its shaft is rotated by G', G", or G'".
If F'and G' had the aume number of teeth each, one revolution
of B would make one revolution of G', one revolution of L, and
one revolution of K ; consequently the feed-nut attached to S.
would be revolving at the same rate as C, and C would not descend.
Id reality G', G", and G'" have a slightly smaller number of teeth
than W, F", and F"'; therefore one revolution of F* causes slightly
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BOBING. 121
more than one revolutioD of G',K movee rather faster than 0, and
C descends slowly. As arranged in this particular case, the gear
P G' causes C to descend i inch for every 300 revolutions,
the gear F" G" gives a feed of i inch for every 450 revolutions,
and F"' G'" a similar feed for 750 revolutions. The driller is
thus enabled to regulate his feed to the hardness of the rock
bored. In practice these three speeds of advance have been found
sofBdent.
M 13 a drum which is used for hoisting the rod out of the hole ;
K is the hinge upon which the whole of the boring head can be
turned, so as to leave the mouth of the hole perfectly free while
raising or lowering rods. U is the thrust register, upon which is
indicated by a dial the resistance exerted by the rock against the
bit. This is an addition of great importance, for by watching the
indicator the driller can detect changes in the hardness of the
strata passed through, and can measure the exact thickness of the
bard and soft beds before he has seen either the cuttings or the cores.
The thrust register prevents the possibility of drilling through a
bed of coal or other mineral without its being noticed, as has
happened when the seam was so soft that it failed to furnish a
core. The rod is lengthened as the drilling proceeds by screwing
on ]Hece after piece between C' and the topmost rod projecting
above the hole.
Mr. Bullock has recently brought out a contrivance by which
the core can be drawn up through the hollow boring rods without
removing them from the hole. The immense saving of time
effected in this manner b of supreme importance when boring at
great depths.
The large rock drill used by the American Diamood Bock
Boring Company,* for putting down holes to a depth of 3000
feet, consists of a 20 horse-power boiler with two oscillating
6-inch cylinders and the necessary gearing for working the drill,
all mounted on & carriage, so that the whole machine is readily
moved from place to place. The feed is effected by gearing, or
by hydraulic pressure, a zf-inch crown b employed, leaving a
3-inch core. Each separate drill rod is 10 feet long. The total
weight of the machine b about four tons.
The newt Victorian Oiant Drill, said to be the largest and most
powerful drill in Australia, contains some improvements suggested
by experience. The cylinders are 7^ inches in diameter, and are
made stationary, because the heavy vibrations of oscillating
cylinders are imparted to the boring rods and diamond bit, and
do harm to the machinery. The winding drum has a friction
pulley and a brake, which enable the rods to be lowered without
working the engine, and so prevent unnecessary wear and tear.
" Eng. Min. Jour., vol. xlviii. (1889), p. 569,
t Victoria, Annuid Seporl of the ISteraary for Mines for Ihe Year 1889.
Helbonme, 1890, p. 35.
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133 ORE AND BTONE-MINING.
VariouB parte are strengthened, and there is an arrangement for
working the steam expansively.
This method of boring is expensive. During the year i88g,
the cost of prospecting for gold by diamond drills in Victoria* was
los. 3jd. per foot boied, exclusive of the wear and tear of
diamonds, taking the average of a total 18,454 feet bored. The
cost for the wear and tear of diamonds for 30,294 feet bored in
search of coal and gold is put down at ;£6ooo, or nearly 4s. per
foot. In the borings executed by the Government of ^ew South
WaleSit the cost for diamonds is very much leas, varying ae a rule
from IB. to 2S. per foot. This may probably be accounted for by
the fact that moet of the New Bouth Wales bore-holes were made
in the comparatively soft Garboniferons strata, whilst some tA
the bore-holes for deep leads in Victoria had to traverse hard
basalt.
The cost at Broken Hill, where a boring 3 inches in diameter
was carried from iiaz feet to a depth of 1880 feet in 1889, was
j£i 9B. io|d., or, roughly speaking, 30s. per foot, exclusive of
office salaries, store wages, rent, and the Superintendent of
Drills' travelling expenses. The rocks traversed wero gneiss,
mica schist and quartzite, sometimes gsrnetiferous. The average
rate of boring was only 571 inches per hour, whilst in the sandstone
and shale of the Carboniferous strata there was a progress of 9
to 31 inches per hour, at a cost (exclusive of the items mentioned
above) of 6s. 2d. to i8b. 4d. per foot. The average working cost
of 7854 feet bored by tiie Department of Mines, New Sonth
Wales, in i88g, including all expenses, was 14s. 3jd. per foot.
Of the total 7854 feet, no less than 7096 were in strata of Car-
boniferous age, and only 758 in metamorphic schiste; the holes
were from 2^ inches to 4 inches in diameter.
With reference to the rate of boring, it must be remembered
that the figures given refer to the speed obtained while the
machine was at work, but the average amount of deepening of
the bole at Broken Hill during the year was little over 2 feet per
day. Omitting Sundays, there were 313 working days, (^y
199, or less than two thirds, were employed in boring; of the
remainder, 86 were occupied in repairing, 15 in reaming, 4 by
delays, 9 by holidays ; the working day was eight hours.
The amount of core obtained at Broken Hill compared with
the total depth bored was as much as 97^ per cent., and the average
for the total 7854 feet referred to above was 8933 per cent,, a
very excellent result.
Small diamond drills, which will bore in any direction, and
which are driven by hand, com|nee8ed air, or electricity, are
largely used underground for prospecting. The hand drill of a
* Op. cit.,v. 63.
t Annual Report for tk« Departmtnt of AlSnti, Netc South Walet,for th«
Year 1S89. Sfdnej, iSgo, p. 139.
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BOEING. 133
Swedish boring company* gives cores J inch in diameter. Ex-
ploration by tbeee little machines is ver7 decidedly cheaper than
by driving or sinking by hand in hard rocks, and fully ten timee as
quick. On the other hand, the ground is not opened out as it would
be by a shaft or drift, and the sample furnished is but small.
Several good veins have been discovered by the aid of the little
hand-machine in Scandinavia — for instance, a copper lode 1 5 feet
f4'5 m.) wide at BOraas, and iron lodes from 32 to 65 feet
10 m. to zo m.) wide at Dannemora and Fersberg.
The hand-power drill of the Bollock Manufacturing Company,
Chicago, is a somewhat similar little machine, and it is said to be
Fio. 105. Fia 106.
capable of boring a hole of i J inch diameter, with a i-^^ inch
core, to a depth of 400 feet.
Machinee driven by compressed air are often employed at
ore mines in the United States for exploratory purposes,
f^. 105 shows the Little Champion prospecting drUI. Two
inclined cylinders drive a horizontal crank-shaft, which works
bevel gear, causing the drill to revolve. At the same time a
counter-shaft is likewise set in motion, and this effects the
advance of the drill by driving the feed-screw, in the manner
already explained in the description of the " Dauntless " machine
* Natdeiiatnim,"DislMamaiitbohTiua8Cbiueiiiit Handbetrieb," B. u. A.
Z. 1SS9, pp. 3S9 and 449 ; and F^tiUm, "Ball. Soc. Ind. ifi'n., 36 S4rie, vol.
IiL(i889),p -
(1889). p. 1395-
(■ Eng. Mm. Jour., vol. zxxiil. (1SS2), p. 119.
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124 ORE AND STONE-MINIHG.
(p. 120). The feed-screw and its connections are carried hy a
swivel-head, and this can be turned so as to drill holes at an
angle. The drum shown above the cylinders is used for hoisting
out the drill-rods by a rope. The rods are lap-welded iron tubes
ig inch in diameter, fitted with a baycmet joint.
Another light portable prospecting drill for underground work
is represented in Fig. 106.* It is intended for drilling boles
i^ inch in diameter to a depth of 150 feet. The cores which it
yields are J| inch in diameter. It has double oscillating cylinders
3^ inciies in diameter, with 3^ inches stroke, which are run up to
a speed of 800 revolutions a minute. The drill can be set bo
bore in any direction by turning the swivel-heed on which it is
carried.
The Sullivan prospecting drill is a diamond borer driven by an
electric motor on the same frame as the drill. The motor also
works the force-pump. The feed is not by toothed wheels as
shown in the figures, but by friction gearing. It will bore at any
angle to a depth of 300 feet.
Ueorgi's t electric diamond drill, pi-imarily intended for baring
holes for blasting, can also be employed for prospecting under-
ground.
SnbBtitutes for Diamonds. — Olaf Terpj uses emery instead
of diamonds. In some cases he puts in the fragments of emery
loose at the bottom of the hole and allows them to wedge them-
selves into grooves in the boring crown, which is made of soft
metal. Another plan is to make the boring crown entirely of
emery. The speed of rotation is three or four times as great as
with diamonds, and holes can be bored from f inch (20 mm.)
to 3 feet 4 inches {i m.) in diameter. Healey bores with small
chilled cast-iron shot, which are dropped into the hole while a
wrought-iron tube is revolving in it. The debris are carried op
by water, and the cores are extracted in the ordinary way.
II. BOBINa BY FEBCTT88I01T WITH BODS.
Iron Bods. — The rods are either of iron or wood. In France
preference is given to iron, and the following details relate to
modes of construction now employed by M. Faulin Arrault,§ the
well-known boring engineer of Paris.
The actual boring apparatus consists of the cutting tool, the
rods, and the driving machine ; but in addition it is necessary to
* Em. Jfin. Jour., vol, xxiiti. (1882), p. 273.
t Jahrb.f. d. Berg- und Ilntteaieeteu im K. Snehseii, 1890, p. 95.
If Olaf Teip's " Bo'brmaachine mit UchmicgBlbobtkrone," II. u. h. Z., 1890,
p. 41 S-
S The fibres are copied b; permission from M. Ariault's work, Outili
el procidii de Soadage. Paris, 1890.
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BORING. 125
liave clearing took, and appliances for remedyiiig acoidents, lining
the bore-holes, and obtaining samples of the rocks travereed.
Cutlittg Tools. — The actual cutting tool is usually a chisel (Fig.
107) of some kind ; for soft rocks the edge is straight ; for hard
rocks there are wings to guide the tool and keep
the hole vertical, or even special guides above Fio. 107.
it. For diameters not exceeding 40 inches (i m.),
there is usually only one chisel; but the actual
catting blade is sometimes made in a separate piece
fastened by gibs and cotters to the tool carrier (Fig.
118). In boring lu'ger holes the chisel is made of
two, three, or four eepsrate blades.
BoriTtg Roda. — The boring rods are made of iron
of square section. The usual mode of connection
is by a screw- joint such as is shown in Fig. 108,
care being taken to have all the bars alike, so
that any two bars can be screwed together. H. Arrault prefers
to have a connecting socket (Fig. 109). The ordinary rods have
a thread at each end, to one of which is screwed a socket or sleeve
which is fixed by a piu. This socket then receives the end of
another rod, wldch is screwed up until both ends meet. When
the thread of a socket becomes worn, it is taken
off and put on to the other end of the rod ; in a JiGs. 108 & 109.
similar manner, if the thread of a rod is worn,
the socket may be screwed on to it and the un-
worn end used in the process of jointing and
unjointing. The rods are generally screwed up
to the right and are turned in that direction ;
but in special cases it may be necessary to have
the sockets fixed by two pins, or to have a
special joint or a left-handed thread.
The height of the tower, derrick, or shears
erected above the bore-hole should be some
multiple of the length of the roils, so as to be able to detach or
attach two or three lengths at a time, instead of having to make
and unmake every joint.
Fio. iio, Pig. hi. Fio. 112.
Arrault's rods vary in length from i foot 8 inches (o'So m.) to
20 feet (6 m.), being usually an exact number of metres, and in
size from | inch (22 nun.) to 3J inches (90 mm.) on the side.
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126 ORE AND STONE-MINING.
They have two Bhoulders at each extremity, so that the upper ooe
can be used with the lifting; hook, Fig. i lo, when the lower is
resting upon the key, Fig. 1 1 1 .
A cap such as Fig, 1 12, may be screwed on and used instead of
the lifting hook for raising the rods by the rope.
Workiiig th« Bod. — The up-and-down movement of the rods may
be obtained in various ways. For depths not exceeding 60 to So
Fia. 113.
feet, nothing can be simpler than the device shown in Fig. 113.
The man at the windlass raises the rods by turning the handle, and
the master borer detaches them and causes them to fall by simply
preesing down the end of the hook, which he holds in his right
hand. The chain is lowered, the hook put in, the rods are raised
by the winch, and then again allowed to fall, the master borer
taking care to turn them a little each time.
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Fig. 114 shows the principal tools supplied by Arraalt for a
small boring.
For greater depths a lever has to be employed, the rods being
suspended at one end, while the other can be pressed down by
men using their hands or feet. The spring pole is another
arraQgement ; the pole is pulled down to make the stroke, and
its elasticity lifts the rod again. The length of the stroke can be
Fio. 114.
I, gnide tube ; z, bit or chisel with wJngs ; 3, Btralgbt bit or
cbiul; 4, ordinary open icoop or wimble; 5, acoop or wimble
with anger ; 6, closed scoop ; 7, ilndger with ball Talve ; 8, beU-
torew or screw grab ; 9, auger ; 10, combination bit and slndger
witb ball valve ; 11, combination auger and sludger with toll
valve; 12, boriog rod; 13, matching piece; [4, wrench for uu-
BOiewing rods ; 15, matching 01 lei^hening piece ; 16, clamp;
17, clamp with eye ; 18, wrench ; 19, retaining or sapportine k^ ;
[, tiller ;
E, double wrench ; 33, scraper ; 34, picker.
k screw 11
rendered uniform during the boring by means of e
swivel-head at the top of the rod.
With deep holes, and especially those of large diameter, steam
machinery has to be employed for working the rod. Arrault
frequency usee a winch driven by steam. The chain to which
the rods are attached passes over a pulley hung from a derrick
and is coiled on a drum, which is loose upon the main axle of the
winch ; it can be thrown in and out of gear by a clutch moved by
a lever. It is eaBy therefore to raise the rods by working the
winch, and then let them drop by simply releasing the clutch.
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laS ORE AND STONE-MINING.
Occaaionally a direct-acting engine is placed immediately
above the bore-hole, but a commoner arrangement is to employ a
single-acting cylinder with its piston acting at one end of a
beam, while the rods are attached to the other end. A favourite
plan also is to actuate the beam hy a connecting rod worked by a
Procem of Soring. — The actiial machinery has now been
described, and the mere boring appears to be a very simple
matter, consisting only in lifting the rod a little and allowing it
to drop, after turning it slightly before each stroke. Never-
theless the process of putting down a bore-hole is far more com-
plicated than it might aeem, for there are numerous operations
which take up much time. In the first place the debris must be
removed by a clearing tool, and before this can be lowered the
cutting tool must be taken off. The swivel-head is disconnected,
and a cap screwed on ; a length of rod is now drawn up by a hand
or a steam windlass, the retaining key is put under a shoulder,
and the joint unscrewed by another key. It is well to have as
many caps as there are lengths to be drawn up, and then each
length can be suspended in the boring house or derrick.
As soon as the hole is free the clearing tool is lowered,
either by the rods in precisely the same way as the boring chisel,
or by means of a rope and windlass. The clearing tool
Fio. 115. is usually a hollow cylinder with an ordinary clack or
i^ a ball valve («A«S ptunp or sludger) (Fig. 115). It is
worked up and down a little till it is filled, and it is
then drawn ap to the surface and emptied. The opera-
tion is repeat«d if necessary, and the boring is resumed
with the rod. Sometimes a cutting blade is added to
V the sludger so that it bores a little and picks up the
B debris at the same time. In certain rocks such as
^ marls, it is convenient to have a shell-pump with a
lip. It is fixed to the rods, and when it is turned a
little as well as moved up and down, it soon fills itself.
Oeynhauaerta Jmnt and free-falling tools. — When a hole of large
diameter is being bored, the weight of the rods is so great
that much vibration ensues when they are suddenly arrested
by the chisel striking against the bottom. Yarious devices have
been contrived for overcoming this difficulty, among which may
be mentioned Oeyuhausen's sliding joint and three methods of
making the tool fall independently of the rod. Oeynhausen's
contrivance (Figs. 116 and 117) consists of an upper piece a pro-
vided with a slot in which the lower piece b can slide ; b is pre-
vented from dropping out by a crosshead and carries the boring
chisel, whilst a is attached to the line of rods.
When a down-stroke is made and the chisel strikes tiie
bottom, the piece a slides over b and is therefore but little
afiected by any jar produced by the blow of the tool. The length
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&-
^
BORING. 129
of the stroke is arranged so that the top of the slot will not
descend far enough to touch the croeshead ; a is then raised once
more and agdin catches the croeshead.
One of the simplest amingemeuta Fias. 116, 117 & 118.
for making the tool fall independently H
is the sliding joint shown in Fig. 118.^ M n
Thepiece supporting the boring tool has
two wings (^g. 119) which rest upon
shoulders, at the top of a long slot in
a cylinder attached to the lowest rod ;
by giving the rods a sharp turn to
the left, the wings lose their support
and the tool drops.
The actual process of boring is
carried on in the following manner : —
Tlie line of rods suspended to a chain
is raised 1^ a steam winch.
Fio. 119. Steam is then shut off, and
themasterborerbyasndden
twist of the tiller causes the
bayonet joint to act; the
tool drops and makes its cut.
The rods are then lowered,
and the slot comes down
over the wings which are
pressed by the inclined sur-
faces at the end on to the
shoulders ; the sLeam is
turned on again, and the operations of
winding ujp, stopping, twisting, letting
the tool fall and lowering are repeated.
The contrivance acts so easily that it is
sometimes nsed even for comparatively
shallow bore-holes.
The free fall is obtained by Arrault in
a different manner when the boring is
done by a beam (Fig. 120). The tool is suspended
from the catch A (Fig. 121). The part ab has a
pin t, which lies in an oval hole. While the rods
are being lifted the beam strikes a bumping-
piece, and their upward movement is suddenly
checked ; inertia carries the catch a fi up a little,
the end a strikes an inclined surface and causes the end h to
move outwards and detach the tool. When the rods are lowered
the part h hooks itself on without difficulty, and the chisel is
raised and dropped.
This tool requires the boring rod to be guided, for otherwise thck
hole might not be bored straight.
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ijo ORE AND 8T0NE-MINISG.
Fi^. 121 ezplaine a well-known free-fallmg tool invented many
years ago by Kind." The head of the actual horing rod is held
by a click or grapple. When the main rod descends, the reaiitt-
ance of the water in the hole checks the sliding disk D ; tbe jaws
J J are opened by the little rod which connects tliem to D, and
the boring part falls and strikes the bottom without any injurious
vibrations being communicated to the main rod. When the disc
descends further, the head is caught again by the click.
Accidents. — Tools for putting things right in case of accident
are numerous, and many of the contrivances which have been
invented by engineers are extremely ingenious.
Among the accidents is a breakage of the rod. If tbe rods are
not caught in any way, a claw called the crow's-foot (Fig. 123) is
lowered and turned round till it catches a rod below one of the
shoulders ; it is then drawn up. Sometimes it is found that a hole
has suddenly deviated from the vertical, owing to a difference in
hardness in the rock, which causes the chisel to work more easily
on one side than the other. One method of remedying this evil
is to fill the bad part with cement, and rebore it very carefully.
Broken ropes can be caught hold of by tools resembling a cork-
screw. The tool shown in Fig. 124 serves to cut a thread upon
the end of a broken rod. The position of the broken end is first
■ J. UsUon, Ltelurei on Mining, vol. i., Atlaj, Plato IX., Fig. 52,
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BORINa 131
ascertuned by taking &□ impresaioa upon ta,ltow or wax, and the
cone ia then lowered on to it ; by turoiog it round a thread
is cut on the broken end, which can now be raised with the rods
and tools attached to it.
If the cutting chisel is broken, some kind of grasping nippers
most be used, and there are contrivances for making them act
when they have reached the bottom of the hole.
Liningt.— Where the strata are soft and would fall in, or where
it is necessary to shut off the inflow of certain water-bearing
beds in order to confine the well to one particular soorce of
Figs. 123 & 114.
S fl
R
Flo. 125.
I
G
supply, the hole has to be lined with a tube, Tubes are made of
iron, copper, or wood. This last material is seldom employed
nowadays, because it occupies so much space, and because it is not
easy to make good wooden tubes.
Fig. 125 is a tube of riveted sheet iron with sockets fixed on,
which enable the joints to be made by screwing. Fig. 126 is a
tube with a screwed joint perfectly smooth outside and inside.
Copper tubes are advisable when the water, such as that coming
from pyritiferous beds, would attack iron and in time eat it away;
but this difficulty is also overcome by putting earthenware pipes
inside, and filling up the interspace with cement.
<7oru.— Though the fragments brought up in the sand-pump
will indicate the nature of the rocks which are being traversed, it
is often desirable to obtain a core of the actual stratum itself,
which will show the direction and amount of the dip of the
rocks, and possibly contain fossils and so afibrd valuable knowledge
concerning their precise age. A core is cut out either by rota-
tion or percussion. In the former esse the tool consists of a
sheet-iron i^linder (Figs. 127 and 1 28) armed at the bottom with
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i^a ORE AND STONE-MINING.
Bteel sawing teeth ; in the latter the cjlinder is surrounded by
four cutting chisels, which chip out a ring and leave a nnlid
cylinder standing.
The core now has to be detached, and for this purpose various
conbiTanceB may be adopted. One of Arranlt's tools is shown iu
Fig. 139. It is a hollow cylinder a attached to the fork 6 e, with a
longitudinal slot containing a sliding bar d, armed with a toothed
wedge e, which is prevented from dropping out by the shoulder y.
The bar d is further kept in position by the spring g h, iixed at
FjQs. 137 & 13S.
FiQ. 139.
o
the top of the tube, which presses it against the two outer plates
ij and the ring it ; Z is a little slot in the spring, and m a small
stud upon the bar d. When this tool is lowu^ over the core
and the wedge e touches the bottom of the annular groove around
it, the tube slides down and forces the wedge inwards; the
weight of the rods causes sufScient pressure to drive the teeth of
the wedge into the core and break it off. In the meantime the
slot I has passed over the stud m ; the wedge is thus prevented
from slipping down, and the core is held till it is drawn up to the
surface.
In order that the direction of the dip may be ascertained from
the core, it is necessary to know exactly how it stood when it waa
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BORING.
133
tn ntu. In Victoria' the rods and the core-breaker are put
together at the surface, and all the joints are marked in a straight
line with a chisel. The rods are then taken apart, and are care-
fully screwed together in precisely the same manner when they
are lowered into the bore-hole. If the position of the marks at
the surface is noted while the core is being detached, the direction
of the dip can at once be determined. To prevent Oie poesibility
of error from a movement of the core after it has been detached,
it is marked while at the bottom of the hole with a vertiod
scratch or groove. This is ma4le by a sharp steel point on the
gripper as it slides down over the core.
A method lately invented by Arrault consists in lowering a
compass, enclosed in a case made of phosphor bronze, on to the
Fio. 130.
Fia. 130A.
top of the core (Figs. 130 and 130A). The caee has on india-
rubber bnse, with two grooves filled with felt impregnated with
a thick ink. The compass case also contains clockwork, arranged
like an alarum, which can be made to liberate a catch and so
clamp the compass. The compass is lowered by a rope, and sufG-
dent time is given to enable it to assume its proper position before
* BoMrtt and StattJiliaoflhe. Mining Department, Victoria, for the Quarttr
ended March ji, tSgi, p. z8, with Plate.
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OEE AND STOKE-MIKING.
it is fixed by the clockwork. It in drawn up, the
core is then extracted, and by meaDS of the ink marks
the compass can be put upon the core in precisely the
same position as it originally occupied in the hole.
Instead of using ink marks, some plastic material*
such as clay may be lowered on to the top of the core
and allowed to remain long enough to take an impree-
mon. A clockwork arrangement in a watertight box
above the plastic lump sets a magnet fast aStae the
lapse of a given time as before, and when the core is
brought up it is placed eo as to fit the impreesionB,
the orientation of which is known by the magnet.t
Wooden Bods. — In some districts wooden rods are
found more suitable than iron ones. They have been
used in Canada, and they are preferred in Galicia.
Fig. 131 represents the manner in which the rods are
made for boring oil wells in that country. The rods
employed inOaUciaareof a^h, 32feet 10 inches (10 m.)
long, and 2 inches in diameter ; at each end a forked
iron coupling is riveted on, terminating b; a conical
male or female screw, and in the middle are two
strapping plates of iron to give more strength and
Btiffiiees. To the end of the lowest rod is attached an
Oeynhausen sliding joint which carries a sinker bar
with the cutting chisel attached to it. The sinker
bar b from ao to 30 feet (6 to 9 m.) long, and weighs
from 12 to 15 cwt. (600 to 750 kil.).
The top cv the line of rods in fastened to a chain
(Fig. 132) ; this makes three turns round one end of
the boring beam, capped for this purpose by a casting
with a spiral groove, and is then wound on to a little
windlass placed on the beam, The beam receives its
up-and-down movement from a connecting rod attached
to a crank upon the axle of a wheel driven by a belt
from a small steam-engine. J
Aft^ boring, the chain is unfastened, and the rods
are drawn up by means of a hemp or manilla rctpe
I J inch (45 mm.) in diameter, which is also used for
working the sand-pump. The master borer can per-
form all the necessary operations while sitting in front
of the hole. By means of the rope a he can work
the windlass upon which the chain is coiled, and by
pulling the lever b he can throw in or out of gear the
• B. V. h. Z., 1890, p. 30S,
+ Jt^xtrU and Stalitlict of the Mining Department, VietoHa,
Quarlrr ended Harch jr, iSgi, Dip cODtrivance, p. 38.
J SyrociyiiBki, "Note sur le forage Canadian," BiJl. Soe.
Ind. Jain., tome lil., 3^ Serie. SaiDt-Etlenne, 1889, p. 1417.
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BORING.
135
pntley which drives the drum with the windiog rope, and bo raise
or lower the rods or the sand-pump. The lever c actuates a,
brake which enables him to stop the machinery, if necessary, and
with his left foot he cau press upon a pedal e, and so regulate
the steam valve, and alter at pleasure the speed of the engine.
Flo. 132,
The cord d works a second steam valve. Two other workmen,
one at the bore-hole, and the other on a platform 33 feet (10 m.)
above him, are shown in the act of unscrewing and putting away
the rods.
During the actual boring, the two assistants stand at the hole
and turn the rods, whilst the master borer regulates the blow by
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136 ORE AND STONE-MINING.
the cord a which cnrnmaDds the wiadlasa, and the cord d which
controls the adroisBion of eteam.
The tower or derrick is about 50 feet (15 to 16 m.) high, and
16 feet (5 m.) square at the base. It ia closed in with planks.
The adjacent space required for the steam-engine, belte, wheels,
Ac., is 35 square yards (30 square nu). The end of the beam
travels about 20 inches (50 cm,); but owing to the inter-
position of the sliding joint the stroke of the chisel is some-
what less. There are about 50 to 60 blows a minute. After
work has gone on for a time, and the debris begin to accu-
mulate, the rods are withdra,wn and the shell-pump is lowered
by the rope. It is a cylinder 33 feet (10 m.) long, with
a valve in the bottom ; it £lb itself, it is drawn up, and the valve
is opened to discharge tiie sludge. In consequence of the light-
ness of the rods, the conidty of the screw joints, and the skill of
the workmen, the various boring operations are carried on with
surprising rapidity. Scarcely half a minute is required for un-
screwing a joint, and a set of rods 650 feet long (aoo m.) is drawn
up or lowered in lo or 12 minutes.
For a hole 1000 feet (300 m.) deep, the four operations of
raising the chisel, lowering and raising the shell-pump, and
again lowering the rods and chisel, do not require more than
an hour.
Three men are required, of whom one is the master borer and
one the engineman. Their wages do not exceed 10 florins a day,
and if the wages of the smiths, who are constantly required, are
added, the total cost of wages per day will be from 15 to 16
florins.
The initial diameter of the hole varies from 9J inches (0*25 m.)
to 15J inches (0*40 m.)Jn loose ground, and the final diameter is
4 inches (o'lo m.). The bole is lined with tubes throughout,
they are made of welded sheet-iron screwed together and perfectly
watertight.
The Bucoessive columns of tubes of the lower part of the hole
are placed one withJa the other. They are not withdrawn till the
hold is completed. The cost of the plant varies from 80^ to
10,000 florins, including a 12 to 15 h.-p. steam-engine, \^ich,
with its boiler, comes to 3500 florins. To this must be added the
cost of the tubing, which, according to the diameter, varies from
3 to 10 or II florins per metre.
The boring contractors ask from 15 to 25 florins per metre for
a bcning estimated to be 1000 feet deep (300 metres), plus 50 per
cent, of the petroleum obtained in the first case, or 30 per cent,
in the latter. They leave the tubes necessary for preserving the
well, provided they are paid one-half of their value. Contract^ are
also made for sinking wells at 50 florins per metre, without any
interest in the output.
As an example of the work, a well was bored 73S feet deep
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BORING. 137
{225 m.) at Wietrzno, by M. Suszycki, beginning with a diameter
of 15^ inches (0*40 m.) and ending with 5 J^ inches ('145 m.) in 90
days, of which 70 were occupied in actual boring. The average
progress waa 10 feet 6 inches per day (3*20 m.),the maximum 32
feet (9'8[ m.) per day. Several wells have been bored to a depth
of 1500 feet (over 450 metres) at Stoboda Runzwoska. Under
some exceptionally favourable circumstances a hole 475 feet
(145 m.) deep waa bored in eight days with 140 hours of effective
woii.
This system, therefore, seema suited to the conditions prevailing
in Qalids. The American method of boring with the rope, which
answers in Pennsylvania, where the beds are nearly horizontal,
did not succeed in Galicia, with the soft Tertiary rocks, which
often dip considerably. As r^ards the material for the rods,
wood is to he preferred to iron in Galicia. Wooden rods are
lighter and more easUy manipulated than iron rods, beeides which
tbey are more easily repaired, a matter of much importance in
disbicts far from foundries and engineering shope.
Driven Welle. — Under the head of boring by perctission may
be classed the process of making driven welts, or Abyssinian tubo-
wells, as they are often called in this country. A tube shod with
steel is rammed down by a heavy weight, raised by men with
ropes passing over a pulley, and then allowed to fall and strike
a stop clamped to the tube. The tube is perforated just above
the shoe, and when a water-bearing stratum of sand or gravel is
reached, water flows into it, and can be piuuped op. Ihb, bow-
ever, is a special process, and can scarcely be considered as true
HI. BOBIITG BT PERCUSSION WITH BOPS.
American System. — The use of the rope for boring is of very
ancient date in Cbina^ and the process has been brought to great
perfection In America for the purpose of obtaining petroleum and
oatutal gas. Within the last few years the American system
has been employed at Fort Glai-ence, on the Tees, for obtaining
brine.*
The first operation consists in erecting the drilling rig, consist-
ing of the derrick, steam-engine, band-wheel, walking beam, bull-
wheel and sand-pump reel.
The derrick (Fig. 133) is a framework in the form of an acute
truncated pyramid, 72 feet high, zo feet by 20 feet at the base,
and about 3 feet squai-e at the top. It is ingeniously constructed
of 2 -inch plank, without any large or heavy pieces of timber, and
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138 OEE AND STONE-MINING.
it seires to carry two pulleys. The reaeon of its beight ie to
enable the driller to raise the whole Btring of boring tools from
the hole without any disjointing.
The engine has a horizontal cylinder, 8 inches in diameter,
with a 1 2-inch stroke, and is reckoned to be ot 15 horse-power.
By means of a belt, power is transmitted to a wooden pulley
(a) called the band-wheel; this is provided with a crank (b), and
tlux)ugh a pitman (c) actuates one end of the walking beam {d),
26 feet long.* A smaller pulley bolted to the band-wheel enables
the, bull-wheel (e) to be driven by an endless rope, and, by means
* The figure shows the pitman taken off from the crank pio.
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BORING.
139
of a lever, a friction pulley {/) can be brought against the band-
wheel BO as to drive the Band reel.
These are the principal parts of the ng. In addition there are
wanted; —
1. A set of drilling tools {h, i,j, k, I).
2. A sand-pump (m), or a bailer.
3. A rope (g) li inch in diameter for lifting the tools.
4. A rope (9') I inch in diameter for working the bailer or
the sand-pump.
Fio. 134. Fig. 135, Fig, 136. Fig. 137. Fig. 138. Fig. 139-
9
i fl
The Bet of drilling tools consist of the following parts :-
DUmebr. Lenpb. Weight.
Bope socket ,
Sinker bar
Anger stem
Fig. 134 (and A, Fig. 133) .
„ 135 (audi „ „ ) . 34
„ i36(indi „ „ ) .
„ i37(andi „ „ ) . 3i
„ i38&i39(*nd;, Fig. 133)
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14° ORE AND STONE-MINING.
The jars tur« like two links of a chain, and their object is to
enable an upward blow to be struck if the bit sticks ; the force of
this upward blow is iacreased by the momeDtutn of the Binker
bar.
The rope socket receivea the end of the boring cable, any part
of which can be connected to the walking beam by a clamp at-
tached to an adjustable link called the temper screw (Fig. 140).
The bailer is a wrought-iron cylinder, 18 or 20 feet long, with a
valve in the bottom, which opens as soon as its projecting stem
touches the ground.
Thesand-pump (Fig. 141) is an iron cylinder, j feet 01- more long,
with a valve in the bottom and a piston. When it is lowered to
the bottom of the hole the piston descends, and when the piston
is i-aised, it sucks the mud and debris into the cylinder, and they
are retained by the valve.
When the hole has to pass through loose alluvial soil, a drive-
pipe (a a. Fig. 350) is rammed down before any true boring begins.
The drive-pipe is made of steel, J inch thick, and is 8^ inches in
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BOBIHG. 141
diameter intemaJl;, It is supplied in lo-feet lengttu, and these
are connected, like gaa-pipes, by screwed sleeve couplings, 14
iocfaea long. The first pipe is shod with a. sharp steel shoe.
The drive-pipe, protected at the top hy an iron cap, is rammed
down by a heavy wooden block (manT), like the ram or monkey of
a pile-driver, working between two vertical guides, and length
after length is added as it descends. The manner in which the
blow is given will be plain from the accompanying diagram (Fig.
I4z),inwliich theguidesareomitted. The manl (a) bangs f rom a
rope or cable which passes over the crown pulley (6) at the top of
the derrick and round the shsft of the bull-wheel (0). Ano^er
rope is attached to the crank of the band-wheel {d), and tied to
the first rope. As the crank revolves it pulls the cable and raises
the maul, and then letting the cable go back, causes the maul to
drop.
When the pipe has been rammed down imtU the shoe is driven
into hard ground, the earth inside has to be removed. A
swivel-head is attached to the rope in place of the block, and to it
are screwed the sinker bar, or the auger-stem, and a bit. This is
worked up and down like the maul, save that it is rotated ; water
is poured in, and soon the earth is knocked up into mud. The
sand-pump is then lowered and the mud brought up. These
operations are repeated, and when 60 feet have been cleared in
this way the i-egnlar boring can be commenced.
The proper cable is placed upon the bull-wheel shaft, one end
brought over the crown pulley and attached to the socket, and to
this, in succession, thesinker bar, jars, auger-stem, and bit. f will
now suppose the string of drilling tools to be hanging in the hole.
The temper screw (Fig. 140, and n Fig. 133) is clamped to the cable,
and its eye hung on to the hook at the end of the walking beam,
the cable is now lowered, and the string of tools hangs from the
walking beam. The engine is set in motion, and as the band-
wheel revolves, the crank turns and causes the walking beam to
move up and down, and the bit strikes a euccessioa of blows at
the bottom of the hole. The driller rotates the tool by turning
the clamp round and round, this causes the slack of the cable to
coil around the part below the temper screw. After a time he
turns the other way, and the coils unwind ; this process is i-e-
peated over and over again. As the hole deepens, the screw
above the clamp is fed out, and when it can go no farther tha
clamp is loosened, and shifted higher up after t£e screw has been
run back.
The gravel, sand, and mud made by the chipping motion of the
bit, are removed by the sand-pump lowered and raised by the
special rope on the sand-pump reel, driven by the friction pulley.
An examination of the small fragments drawn up in the aand-
pnmp, tells the driller what rocks he is passing through. The
two operations, drilUng and dearing out, are repeated until the
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142 ORE AND STONE-MrNING.
hole has reached the required depth. At Fort Clarence the hole
has to be lined with a steel tube (Fig. 350, in which the tare
of the tubes is greatly exaggerated), 6| inches in diameter in-
ternally ; for the first 150 feet from the bottom the steel is half
an inch thick, then five-cdzteenths of an inch for 300 feet, and
the remainder quarter-inch thick. With the sleeve couplings
over them, they just pass down the drive-pipe. In the rock-Bfdt
and in the 600 feet of wateivbearing sandstone, the lining pipe
is perforated with holes one inch in diameter, and 12 inches apajt
verticaUy."
By the American system the cost of a brine welt at Port
Clarence, 1000 feet deep, including the rig and a share of the
boiler, is ^1000, and it is drilled in three weeks.
Borne wells bored by the diamond drill, on the other band, cost
j£^ooo each, and took three months to make.
The American system presents, therefore, very great advan-
tages, especially in the case where holes have to be numerous, and
where it is not certain how long a well will retain its productive-
nees. On the other hand, in making preliminary explorations of
the rocks of a new district, the diamond drill may fairly claim
the superiority, because it furnishes actual cores, showing the dip,
which give a better idea of the strata than pounded fragmeots.
Though to Enghsh eyes the American " rig " appears rather
rough, we cannot but admire its effectiveness, and also its suit-
ability in the case of petroleum and brine wells. The " rig " erected
for boring is utilised for pumping when the hole is completed, so
that there is no unnecessary expense in the plant. The various
parts of the " rig " are vety simple in construction, and as timber
is lai^ely used in place of metal, repairs can be done by the
master driller, without the aid of fitter or foundry .f
Mather and Flatt'e System. — Another method of boring
with the rope is that which is employed by Messrs. Mather and
Platt.J Its peculiarities are a flat rope, and a special contrivance
for rotating the chisel.
Fig. 143 represents a side elevation of one of the boring
machines.
A A, flat hempen rope 4J inches broad, by ^ inch thick ; B B,
boring head ; C, drum or reel for the rope, driven by the steam-
engine D ; E E, wooden or cast-iron frame ; F, guide pulley ; G,
flanged pulley carried in a fork on the top of the piston-rod of a
vertical Bingle-acting steam-eDgiue shown by the dotted lines,
* For the process of obtaining Che salt lee Chapter TI.
"t Hbd; of mj flgores and ooo&donat eiplanations ore borrowed from
the nsefol Illnjstrated CKtal<^Qe of the Oii Well Sapplj Co., Limited, of
Bradford and Oil Cit;, Pennsjlvania, who have fami^ed both the plant
and the driUers for the wellg bored on the American system at Fort
C\xreaix.
t W- Hatber, "On Well-Boring and Pnmplng Machinery," Proc. inil.
JfroS. Eng., 1869, p. 278.
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ORE AUD STONE-MINING.
,Gooj^Ic
BORING. 145
J is a clamp by which the rope A is fixed while boring is
going OD.
Steam is admitted below the piston (Fig. 144) raising the
pulley G- ; at the end of the stroke, the exl^ust valve is opened,
the steam escapes, and the {ueton, pulley, rope, and boring head all
drop. The exhaust port is so arranged as to leave a cushion of
Hteam which prevents the piston from striking the bottom of the
cylinder. The steam and exhaust valves are worked automatically
by tappets, M M, actuated by the piston-rod. The length of the
stroke can be varied from i to 8 feet by shifting these tappets.
The usual speed is 34 blows a minute.
The boring head (Fig. 145) forms a special feature of Mr.
Mather's invention. The chisels or cutters D are fixed by nuts
in the cast-iron block C ; £ is a cylindrical block serving as a
guide, and F is a second or upper guide which assists in
effecting the rotation. On its circumference there are ribs
which catch in one direction ; they are placed at an inclination,
like segments of a screw thread of very long pitch. Each
alternate plate has the projecting ribs inclined in the opposite
direction, so that one-half of the bars turn the rod round in
rising, and the other half turn it in the same direction during
the descent ; but they simply assist in producing the rotation
which is mainly secured by the contrivance represented above F.
Two cast-iron collars, G and H, are cottered to the top of
the bar B, and their deep ratchet-teeth are set exactly in line
with one another. J is a movable bush sliding upon the bar B,
and attached to the boring rope by the bow K and a short piece
of chain.
The bush J has ratchet-teeth on its upper and lower faces, but
the upper teeth are set half a tooth in advance of the lower
ones. During the ascent of the rope, the bush has the position
shown in the figure ; but when the tool strikes the blow, the
bush descends, and the centre of the inclined surface of each lower
tooth of J strikes the point of a tooth of G, and then slides down
on it, twisting J, and with it the flat rope, to the extent of half a
tooth. At the commencement of the hft the bush J receives
a further twist of half a tooth by coming against H. The flat
rope is thus twisted altogether to the extent (£ one tooth, and in
untwisting it turns the tool a like amount ; automatic rotation of
the cutters is thus secured.
F (Fig. 143) is the shell-pump, or sludger, and Q is an overhead
suspension bar by means of which it is brought over the httle
table B in the tank T. The screw S serves to raise the table K
untal the pump rests upon it, and on knocking out a cotter in the
rod which supports the seating of the bottom valve, the sludge is
speedily discharged.
One man can attend to all the operations of raising and lower-
ing, changing the boring tool for the shell-pump or vice vertd.
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146 OBE A2JD BTOME-MINING.
Fia. [45.
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BORING.
"47
and regulating the boring. Two laboureru are employed to
change the cutters and clear out the shell-pump.
Cores may be cut out as in other systems of boring, and
extracted, so as to show the nature and dip of the strata. As the
rope is flat, cores can be brought up without any twist.
The flat rope method is used by Messrs. Mather and Piatt for
holes from zo inches to 45 inches in diamet«r. In the case of
small holes from which no cores are required, they now adopt the
American system on account of its ezpeditiousness.
iVora what has been said it is very evident that agreat diversity
of practice exists in making bore-holes, and the nuner may have
some difficulty in making up his mind which system to adopt for
any given purpose. In the case of large undertakings, he usually
applies to some firm of engineers, who by long and constant expe-
rience in their art are able to guarantee success.
Burreying Bore-holea. — It is often assumed by boring engi-
neers that the holes which they drill are perfectly vertical : but
experience has shown that this is not always the case. It is,
therefore, important to have some means of measuring the devia-
tion of a bore-hole from the vertical, and surveying its exact course.
A useful instrument for this parpose is Macgeorge's clinograph.*
It consists in the main of two glass bulbs, the upper one carrying
a plummet, tbe lower one a magnetic needle ; both bulbs are
filled with gelatine. When hot the gelatine is liquid, and the
plummet and the needle are free to move ; when the gelatine is
cold both are set fast. The gelatine simply sei'ves as a clamp
which will act of itself after a certain time.
The exact construction is expl^ned by Fig. i46.t The instru-
ment consists of a cylinder terminating in a short neck
and a bulb at the bottom. In this is a magnetic needle Fia. 146.
attached to a hollow pear-shaped glass float, which will
always stand upright upon its pivot and so enable the
needle to swing round without touching the sides. A
smaller glass cylinder, with a bulb at tbe top, is inserted
through an air-tight cork and a brass capenle at the upper
end of the lai^ one. Its lower end passes into a cork,
which prevents the escape of the float of the needle.
The upper bulb contains a delicate plummet of glass,
with diminutive hollow float at the top and a solid ball
at the bottom, which is prevented from dropping out by a delicate
grating. It is carefully adjusted to the specific gravity of the
solidifying fluid which fiUs the cylinders and bulbs, and is so
anang«d that it will assume a vertical position whenever it is free
to move.
* "The Clino^ph," Eiiaiiteeriag, vol. xxiix. (1885), p. 260. "The
Diamoad Drill Clinameter." .Wii. Jour., voL liii, (1883), p. 1509.
t Brongb, Mitie •'iurvti/ing, p. 176.
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148 OEE AND STONE-MINING.
In order to make use of these dip-recorders, or cltnoHaU, as
Mr. Macgeorge calk them, six are placed in a, bath of warm wat«r,
which is heated nearly to boiling. In the meantime a brass
cylinder is also heated by filling it several times with boiling
water, and when the clinostats have bees inserted one after the
other into it, it is lowered into the bore-hote and allowed tq
remain there for two or three hours. By this time the gelatine
will have set ; the brass esse is drawn up and the clinostatG are
examined one by one in a special inntrument designed by Mr.
Macgeorge, This has an arrangement for placing the clinoetat
in exactly the same position which it occupied in the bore-hole,
and for enabling its angle of inclination and its magnetic bearing
to be measured very accurately. The mean of the six sets of
obserratioDB is then taken as representing the correct deviation.
If a bore-hole is approximately vertical, and the strata com-
paratively cool, the brass tube containing the clinostats may be
lowered with & wire rope ; but if the strata are hot or the bore-
hole somewhat £at, ^inch iron pipe is employed for inserting
the brass case. Care is taken to interpose a distance tube of
brass between the case and the pipes, to prevent their action on
the magnets. If the bore-hole is warm, cold water in forced down
the pipe so as to flow outside the case with the clinostats, and
congeal the gelatine.
If observations are made at regular intervals, say at every loo
feet, the path of the bore-hole can be traced with great accuracy.
The apparatus may also be used over a core extractor when it
is necessary to ascertain the direction and amount of the dip
of the strata. Macgeorge employs a brass tube set eicentric-
ally, and provided with a bell-mouth below. This receivee the
end of the core, and the escentridty of the tube causes pressure
on one side which makes the core break off. The cure-extractor
contains an inner tube, slotted from end to end, which expands
as the core enters it and nips it tightly.
Mr. Macgeorge gives numerous instances of ascertained deflec-
tions of bore-holee. At Scotchman's United mine, Stawell, Vic-
toria (Figs. 147 and 148), a bore-hole 370 feet deep, put down with a
diamond drill, was found to have a deviation of 37 feet 3 inches.
It is calculated that ^^3311 would have been saved if the
path of the drill had been surveyed before the driving was com-
menced. At the Oriental Company's mine a bore-hole turned
oat to be 60 feet 9 inches out of its proper course in a depth of
425 feet. Similar cases of deflection have been noted in bore-holes
made in Qermany both by the diamond drill, and by the percussive
method.
The deviation from the vertical may likewise be recorded hy
Nolten's* method, which depends upon the etching action of
* F. K., "The Deviation of Bore-boler," CollUry Quardian, vol. llii,
(1887), p. 77S-
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BORING.
Figs. 147 &. 14S.
A, abaft ; B, EappOMd position of the bore-hole ; A B, level
driven oat from A to strike tbe bore-bole ; C, actual pOBitioD of
the bore-bolea; D, B, If, G, diivages luode in warcb of tbe bore-
bole. The section shows that if the bore-bolehad been continued
to a depth of 500 feet, tbe deTiation would have amounted to 75
feet.
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ISO ORE AND STONE-MINING.
hydrofluoric acid upon glass. A glass cylinder with a truly flat
bottom, and the ludee at right aoglea to the base, is partly filled
with dilute hydrofluoric add, pat into a case, carefully lowered
into the hole, and allowed to remain there for half an hoar. The
acid aats into the glass, which is then drawn np. The line of etching
reoorda what was the horizontal plane when the i^linder was in
the bore-hole, and the angle between it and the flat bottom
measores the deviation from the vertical.
TrouT^* has designed an electric lamp with a mirror set at an
angle of 45°, which is lowered into the bore-hole and gives an
image of the strata. The observer at the surface examinee this
image by means of a telescope.
• E«ff. Mill. .Tour., vol. 1. (1890), p. 4K3.
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( 151 )
CHAPTER IV.
BREAKING GHOUND.
Hand tools: Shovel, crow-bar, piclc, wedge, saw ; tools lor boring holes. —
ICscaTating machinerj.— Tmnamiselon of power bj ali, water, and
eleotricitv. — Diggers, dredges, rock-drills, grooTe-cutters, tanBellerfi.
— Explosives and blasting. — Driving and sinking. — Fire-setting. —
Excavating bj water.
HAND TOOI.8. — The kdnde of ground in which mining
operations have to be carried on vary within the widest limita,
from loose qoioksands to rocks which are so hard that the best
stael tools will scarcely touch them.
Shovel. — Loose ground can be removed with the shovel.
Probably Bome of the first digging tools were merely pointed sticks ;
indeed, the Burmese workman of to-day uses an iron-shod stake
for (dnking oil-wells. Shovels vary a good deal in shape and
make, according to the special purposes for which they are
employed, and also according to the fancies of the users. The
plate or blade is usually made of steel, and it is pointed in front,
MO as to penetrate easily into the earth or stone that has to be
moved. A wooden handle is attached to it by a socket or two
long straps. The handle is often made of ash, and is usually
short, but in Cornwall and Devon a long one is preferred.
In dealing with clay and sticky earth it is advisable to have the
plate as smooth as possible ; the shovel with a hollow underneath
lit the junction with the socket is objectionable for material of
this kind, because the cavity becomes choked, and the tool is then
less easily wielded. Even the projecting rivets sometimes used to
attach the socket to the plate cause a slight hiadranoe, which
means unnecessary waste of power. Shovels, like all other hand
tools, should be made as Ught as po:^ibIe, consistent with strength,
in order to relieve the workmen from the unprofitable labour of
moving useless dead weight.
In the special case of peat, sharp spades are employed, which
cut through the woody hbres, and furnish lumps or sods of con-
venient form for drying and for subsequent use as fuel.
When it is desired to separate the larger stones from all finei-
material, a fork with several prongs is a convenient tooL
Ctowbar. — ^This tool is an iron lever; it is used for prising off
blocks of stone, and for shifting them after they have be^ii
detached.
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iSa
ORE AND STONE-MJNINO.
Pl(&. — What is called fair, soft, or easy ground, such aa clay,
shale, decompoaed day-slate, and chalk, requires the use of the
pick and the shovel ; tlie pick breaks up the gronud, and the shovel
aervee to shift it. The pick is a tool of variable form, according
to the material operated on. Thus there are the navvy's pick, the
poll-pick, with B, point and a striking end (Fig. 1 49), and numerous
varieties of the double-point«d pick (Fig. 150), the special tool of
the collier, but also lai^^ly used in ore and stone mining. The
Via. ]$i. Fig. 15a.
-^
blades of picks are made either of iron with st«el tips, or else
entirely of steel. The latter is preferable, as it lasts so much
longer. The tip may be a point or a chisel edge. The blade is
iistially set at right angles to the hilt or handle ; but at the under-
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BREAKING GROUND.
153
groaDd stone quarries at Bath and Weldon it is oblique, as ehown
in Fig. 151. The object of this form is to enable the miner to cut
well into the oomers of the deep horizontal groove required for
excavating the stone. This pick weighs 5 Ibe.
Bloated picks are sharpened by having the poiats heated in the
blacksmith's fire, hammered to the proper shape and tempered.
In order to save the trouble of carrying a large supply of toob,
the blade may be made separable from the hilt, and the miner
takes the blades only to thesmithy when they are worn. Fig. 152
shows a pick of this description uaed at Mansfeld.
Two w^l-known forms of pick with separate blades are the
" Acme " and the " Universal " of the Hardy Patent Pick
Company.
The Aome (Fig. 153) is a pick used for " holing," or cutting a
groove in a soft rock, in which case it is advisable to have the tool
Fio. 153.
FiQ. 154-
M
aa narrow as possible, in order to avoid the unnecessary work which
a broad eye would occasion. The blade is made with a notch at
the top, and a wedge makes it fast to the head ; blades vary from
i^ to 3 lbs. in weight.
The I7ntvar«a2 (Fig. 154) has the large end of the shaft or handle
fitted with a cast steel or malleable iron socket; the small end is put
through the eye of the blade, which becomes firmly fixed, because
the socket and eye are carefully made to gauge. By striking the
small end of the handle on the ground the blade is loosened and
removed. Bladee of various shapes may be fixed upon the same
handle, which is sometimes an advantage in remote districts.
The handles (" hilts " or " shafts ") are commonly mode of ash
or hickory. In Australia and New Zealand the wattle furnishes
a light, tough, elastic, and durable wood for the handles of picks
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154 ORE AND STONE-MINING.
and other took. One of the best deecriptionii is the Golden Green
Wattle {Aeada decmrtm, var. moUia).
Wedge. — When the ground, though harder, is nevertheless
" jointy," or traTeraed by manj natural fissures, the wedge comee
into play. The Oomish tool known as a gai is a pointed wedge
(Fig. 1 55). -The so-called " pick and gad " work oon-
Fio. 155. siatfiin breaking away the eafly ground with the point
of the pick, wedging off piecee with the gad, driven in
by a sledge or t^ poll of the pick, or prising tliem off
with the pick after they have been looeened by the gad.
The Sason gad is held on a little handle, and is
struck with a hammer. It is used like the Cornish
gad for wedging off pieces of jointy ground, and in
former days even hard rocks were excavated by its
aid. The process consisted in chipping out a series of parallel
grooves, and then chipping away the ridges left between them.
As a method of driving levels or sinking shafts, this process is
naturally obsolete ; but it is useful on a small scale for cutting
recesses {hitchet) for fixing timber, for dressing the ddes of levels
or shafts before putting in dams, and for doing work in places
where blasting might injure pumps or other machinery.
Saws. — Freestone is sometimes excavated by sawing. The
saws are 6 or 8 feet long, and i foot wide. The wooden handle
can be fixed eo tbat no part
Fio. 156. projects above the saw when
...,ft —> the tool is used dose to the
N| roof (Fig. 156).
_. ,1 ■■'- Tools used for Boring
andBlasting.~We now come
to bnrd ground; and in this
class we have a large propor>
tion of the rocks met with by the miner, such as slate of rarious
kinds, hard grit and sandstone, limestone, the metamorphic schists,
granite, and the contents of many mineral veins.
Rocks of this kind are attacked by boring and blasting. The
tools employed are the auger, jumper, or borer (drill), hammer or
sledge {jRtUkt, Cornwall), scraper and charger, tamping bar or
Btemmer, pricker or needle, claying bar and crowbar.
■Aufferi. — At English gypsum mines a tool resembling the car-
penter's shell-auger is regularly used for boring holes for blasting.
It is worked by a cross handle, and makes a hole i\ inch in
diameter. Boring is done in the bitumioous limestone of Seyssel
by screw-augers in a similar manner.
EUioU DriU. — Screw-augers mounted upon stands are common.
Fig. 157 represents the Elliott drill, which consists of an auger
inserted into a socket upon a feed-screw c, which works upon a
worm-wheel a, held fast in a ring, when the screw clamp 6 is
tightened. On moving a ratchet brace backwards and forwards.
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BREAKING GROUND.
iSS
c ia turned round, carrying the auger with it, and when the worm-
wheel is tight, it advances slowly at the same time. If a very
hard piece of rock prevents the penetration of the anger, the
worm-wheel elips in the ring, and, by suitably arranging the
tiglitnees of the clamp h, the machine can be made to accommo-
date its advance to the nature of the rock.
The drill itself is made of a bar of twisted steel, which clears
itself of the debris to a certain ext«nt ; when it has penetrated as
far as it will go, the clamp is loosened, enabling the feed-
screw to be drawn back rapidly without rotating at all. A longer
drill is put in, and work continued.
The light frame or standard ifi made in two halves, and by
shifting a pin its length can be altered to suit the height of the
Fro. 1 57.
Yio. 15S.
working place, whilst the final tight«uing is done by a screw at
the bottom.
BtUcket iJrill, — Where even more simplicity is required, a self-
feeding ratchet drill can be employed, with a piece of timber set
up in the working place as an abutment. An auger is inserted
into a socket upon a feed-screw a (Fig. 158), working in the nut b,
attached to a long sheath. When the ratchet handle c is worked, a
revolves and at the same time advances from the f eed-nnt, carrying
the auger with it. The sheath is prevented from turning by
putting the eye of a pin over one of the projecting pegs at the rear
end, and allowing the pin to be brought up by the first twists against
the piece of timber. For enabling the feed-screw, after it has
advanced to its full length, to be quickly returned into the sheath,
the Hardy Patent Pick Company sometimes use Stayner's Patent
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156 ORE AND STONE-MINING,
k: I
a...:.- fl i O-
Fio, 159. Fio. 161. Fig. 160. Fio. 162. Via. 163.
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BREAKING GROUND. iS7
8plit Nut, ioatflad of an ordinary nnt; when the split nut u
loosened, the feed-screw can be moved back without Iobb of time
in turning. '
Theee augers worked bj hand will do good work in moderately
hard ground, such as tough shale, slate, and even Bandstone.
Jtanper. — The simplest tool for boring holes by percussive
action is the jumper, a bar of iron tipped with steel, forged into
a chisel-ehaped edge. It is struck against the rock, and turned
a little at each blow, and in this way chifis out a cylindrical
hole.
Fig. 159 represents the jumper used ia the lead-bearing sand-
stone at Mechemich, made of a bar of iron | inch in diameter,
and 7 to 10 feet in length. As the rock is soft, the cutting edge
can be made wide and sharp. The exact angle of the actual
cutting edge of a jumper which I measured was 42° ; the final
sharpening is done with a file. At the open workings for iron-
stone in Northamptonshire, the edge comes to a point in the
middle (Fig. 160).
The jumper used in the Festiniog slate mines (Ftg. 161) has a
swelling in the middle, and both ends are sharpened ; the short
end serves for beginning a hole, the large one tor completing it.
The ordinary sharpening is done by heating the end red-hot, and
filing it to the desired form while the jumper is held in a vice. It
is allowed to cool gradually, and then is heated again in the foi^,
hardened in water and tempered.
The jumper for boring holes at any angle Id the rock-salt of
Oheahire has a swelling in the middle, and tapers gradually to
each end.
The jumper of the Cleveland ironstone miner (Fig. i62)has the
swelling at one end, and will bore boles at any angle. Like the
Festiniog tool, it Is sharpened by beiug hammered into shape, and
finally filed when hot.
Borvra. — When the rocks are harder, and also in situations
where a jumper cannot be wielded, the miner must have recourse
to the borer or drill, which is simply a steel chisel (Fig. 163).
The steel is brought to the mine in the form of round or
octagonal bars, and is cut up by the mine-smith into pieces of
the required length ; one end is forged into a chisel-shaped
edge, the exact shape and degree of sharpness varying according
to the hardness of the rock. For band-drilling the steel is usually
§ inch to I inch in diameter, but j inch or even i inch steel is
sometimes used. The old plan of making the drill of iron, and
welding on a piece of steel for the cutting edge {bit), is almost
extinct in this country.
The shape of the bit of the hand drills used at Minera mine,
}Tortb Waiee, is shown in Figs. 164 and 165, the angle of the
edge being 84* The drills used with the compressed air machinett
at Minera are rather blunter than a right angle. At a limestone
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ORB AND STONE-MINING.
quany, near the mine, the drills have two cutting edges arranged
in step-fashion.
Drills for hard rocks are sharpened entirely at the forge; the
cutting edge is hammered into the desired shape on the anvil
while red-hot, and then hard-
FiGS. 164 & 165. ened to suit the particular
\- ■ ■ ■ iH.^ - • requiremente of iho user. In
many cases the desired temper
is obtained by plunging the
tool when at a blood-colour
into cold water, and allowing
it to remain there ; but for
Eoft rock the tool will work
efficiently after the hardness
has been reduced by anneal-
ing. In the case of slate the
smith heats the end of the
jumper to blood-colour, and just dips the edge into water for a
few seconds. He now watches its colour as it cools down, and
stops the annealing or tempering action by plunging the tool into
cold water when a certain shade of blue has been reached. Some
smiths rub the edge of the tool upon a piece of board with a tittle
sand, in order to be able to follow the changes of hue with pre-
cision.
Before the introduction of machines, as many as fifty drills
were aometimee blunted in boring a hole 2 feet deep by hand at
an iron pyrites mine in Carnarvonshire. This is an exceptional
case, but nevertheless the importance of having a good smith at a
mine where much eharpeniiig has to be done cannot be over-
estimated.
A tool called a "bull" is employed in boring holes in tough
hematite and tough clay in some districts. It is a bar pointed at
one end and provided with an eye at tbe other. It is driven into
the ore with a sledge, and by putting another bar through the
eye it can he withdrawn without difficulty. There is practically
no difference between it and the claying bar (Fig. 173).
Sammen. — ^The hole is bored by striking the drill with a
hammer or sledge, and turning it after each blow. Boring is
said to be single-tunded if the miner holds the drill in one hand
and wields the hammer with the other ; whilst it is called double-
handed when one man strikes and another turns. Sometimes
there are two men to strike, one after the other, whilst a third
man turns the drill.
In starting a hole a short drill is chosen, and longer ones are
taken as the hole is deepened; the smitJi is careful to make
the cutting edges (hits) diminish slightly in width as the borers
increase in length, because the hole gradually decreases in
diameter as the tool wears. The bore-bole is therefore not a true
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BREAKING GROUND.
159
cj'liQder, but a frustum of a very elongated cone. It may even
happen that, owing to the man per in which the miner has turned
his borer, the section of the hole forms a triangle and not a circle.
The deep holes bored for quan-ying granite inviiriably become
triangular after a small depth has been reached ; but
the sides are stroighter aud the comers less sharp Fig. 166.
than shown in Fig. 166, which represents a shape
sometimes seen in slate.
Boring hammers and sledges are almost universally
made of steel ; but until comparatively lately iron
hammers with a steel face or pane were common,
and even in some districts t.he head of the hammer was made
entirely of iron, which was worn into a deep bole by the end of
the bard steel drill.
The hammers for single-handed boring vary in weight from
2 to 6 or 7 lbs. The hammers used by the Festiniog miners and
quarrymen weigh from 5^ to 7 lbs(Fig. 167). The handle is toto
13 inches long. In some districts the head is curved slightly, so
Fio, 167.
r
r 1
L
as to follow the circle in which it is swung. A good miner should
be able to wield the hammer with either hand, because he may
have to put in a hole close to either side of a level or stope ; he
should also be able to strike upwards, because occasions arise
where a hole bored in this manner will be far more advantageous
for removing rock than one bored downwards.
The double-handed boring hammer or sledge {mallet, Coraw^)
weighs from 6 to 10 lbs. or more, and the handle is 2 feet or more
long (Fig. 168). If swung round by good hands, it strikes a very
powerful blow.
In a rock-boring competition in Cornwall* a few years ago, three
men from Tincroft mine, two strildng and one turning, bored a
hole 13 inches deep in hard granite in 6 minutes 43 seconds,
• The Well BrilOB, Aug. 9, 188S,
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OEE AND STONE-MINING.
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making 91 blows per minute ; three men from Dolcoath bored
13 J inchtsa in 7 minutes 18 seconds, making 130 blows per minute,
whilst a like number from Cam Brea bored 12^ inches in S minutes
with 117 blows per minute. The Tincroft men
Fig. 163. slung the sledge round, the others did not. The
drills used were made of steel, i inch in diameter;
bub there vas no restriction as to the size or shape
of the bit. Of course these results are simply use-
ful as showing what can be done under very favour-
able circumstances, and for a very short time.
If the hole is directed downwards, the miner
throws in a little water and bores the rock wet. A
ring of rope or leather put round the drill preveDts
the water from splashing him. The water serves
three purposes: it renders the boring easier by
holding the fine particles in suspension inst«ad of
their lying at the bottom of the hole ; it keeps the
toot cool, which makes it last longer, and it prevents
dust, which would otherwise be breathed by the
_ miner and tend to cause lung disease. In places
where miners are paid by the depth bored, a higher
price per inch is sometimes given for boles bored dry than for
thoee bored wet. The depth bored varies with the rock, and the
nature of Uie excavation ; but in driving levels in the ordinary
way by hand, the depth is commonly from 18 inches to 3 feet.
Soraper. — From time to time the miner draws out the sludge
with a " swab-stick," or the dust with a scraper. The former is
a wooden stick with the fibres at one end frayed into a sort of
mop ; the latter is a little disc at the end of a metal rod. For
removing small bits of stone a rude syringe, called a " gui^i" >&
occasionally employed ; it is a piece of gas-pipe, or an old gun-
barrel, fitted with an iron piston made tight by hemp. It also
serves for flushing out " uppers."
The accessory tools required subsequently for charging the hole,
are the tamping-bar or etemmer, pricker or needle, charging-spoon,
cartridge stick, and claying- bar.
TampxTig-bar. — The tamping-bar or stemmer is a rod of wood,
iron, copper or bronze, or iron shod with copper, and it is used
Pio. 169.
for ramming in clay, pounded slate, sand, or the dust from the
bore-hole or other suitable material upon the esploeive, and so
causing a resistance sufficient to make the gases generated by the
blast rend the rock in the manner required.
The tamping-bar (Fig. 169) issometimesa plain metal rod, with
a little swelling at the striking end, but often a groove is left to
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BBEAXINQ GROUND. 161
lessen the chance of injurioff the fuse ; the use of this groove is
more apparent when the pricker is employed.
Priekor. — The pricker or needle {Fig. 170) is a slender tapering
rod <S coppar or bronze with a ring at the large end. It is used
Fig. 170.
=s&
for maintuning a hole in the tamping through which the chaige
can be fired by & squib, rush or straw.
Charging-^oon. — The charging- spoon is a hollow half-
cylinder of copper or zinc, at the end of a copper or wooden rod,
which is used for introducing loose gunpowder into holes which
01 ' '
are more or less horizontal. The scraper and spoon are often
combined (Fig. 171). In the Festiniog slate mines, a copper tube
5 feet loDg, with an expanded mouth, is sometimes used fur putting
a second charge of gunpowder to the bottom of a hole which has
simply produced a rent, without severing the block of Elate from
the workibg face.
Under the Coal Mines Regulation Act of 1887, prickei^,
scrapers, chargers and stemmera must not be mude of iron or steel ;
the Metalliferous Mines Act, 1873, likewise prohibits iron orst«el
prickers, but allows iron stemmers, provided they are not used in
the early part of the operation of tiimping.
C<ui3-idge Sti{:k. — The cartridge stick is a smooth cylinder of
wood, around which paper is beut in order to make cases for
holding gunpowder or the tamping material, when these have to
be inserted into holes which have a very decided upward inclina-
ttOD.' The paper is fastened by a little pitch softened in tlie
miner's candle. One advantage of cartridges for all holes is the
absence of danger from grains sticking to the sides; when powder
is put in looee, a premuture uzplosion may happen from such
gmina being ignited during the process of tamping and conveying
fire to the charge.
Clajfing-bar. — The daying-bar (J"ig, 172) is a smooth rod of
steel a, expanded at one end into an eye e. It was used formerly
for lining wet holes with clay, and eo rendering them temporarily
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OBE AND STONE-MINIKG.
watertight, and fit for holding a charge of gunpowder. Lumps
ofclaywerepnt into the wet hole, and the claying iron was driven
in by blowB on the head b, forcing the clay into every fiseure. By
putting an iron bar through the eye, it could easily he twisted and
withdrawn. NowadayH wet holes are almcet invariably charged
with some nitro-glyoerine explosive, and the cltiying-bar is rarely
required.
Hendhig Holes. — Where a stone can be made to rend along
cortain lincfi, coet may be saved by shaping the holes so as to start
Via. 173.
Fid. (74,
o -o-
the rifts in the desired directions. This is the principle of the
Euox* system of blasting employed at the sandstone quatries of
Portland, Conn., and elsewhere in the TJnited States. A round
hole (Fig. 173) is drilled by hand or by machine, and then two
V-shaped grooves (Fig. 174) are cut down with a reamer (Fig.
175) in the line of the proposed rift. The tool I
Fia. 175. found in use at Bei'ea, Ohio, is slightly different
in shape, but acts in the same way. The hole,
when fired, produces a crack or rift in the direction
AB. Seveml holes may be bored in a line if neces-
Bsry, and fii'ed simultaneously by electricity. The
Githen system, lately a»Iopted by the Ingersoll-Ser-
geant Bock Drill Company, goes a step further ; for
machine drills are now being made which will bore
holes with an elongated section in one operation.
TTSS OF UACHIHSBY FOR BBEAKUTG-
GBOTTND, — One of the greatest improvements in
the art of mining during the last quarter of a cen-
tury has been the introduction of machines instead
of human power, for performing some of the most
laborious work in mining ; the mine-owner is able
to have work done more quickly and more cheaply,
y\ K and the working miner is relieved from severe toil
'.^^v^^i^ under unfavourable conditions.
^ ^-^ The power may be generated on the spot, or am
be transmitted underground from prime movers
on the surface.
As means of generating power on the spot we may turn to
stpam, water, or petroleum,
• Ranndere,
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BREAKING GROUND. 163
Though boring machines in open quarries are often worked by
steam supplied from email boilers which can be moved about oh
tracks, appliances of this kind are out of the question in most
undeiground workings, on account of the nature and small size of
the excavations, the inconvenience and danger caused by the
fire and beat, and the trouble of getting rid of the products of
combustion and of the exhaust.
Power can be obtained by bringing down water in pipes from
the surface, or from overlying strata in which it is dammed baok
by a watertight lining (tiMxiig). This method has the advantage
of requiring no plant except the pipes, but there is the disadvan-
tage that the water must be pumped up again, unless the workings
ore drained by an adit level. However, it may be cheaper and
easier to work the ordinary pumpe a little faster than to erect
special air-compressing machines. Hydraulic power hae the dis-
advantage, compared with pneumatic power, of not ventilating the
workings ; and in certain cases, when the floor is soft and clayey,
or composed of rock-salt or saliferous marls, the flow of water
would he objectionable.
The petroleum engine, an invention of modem times, is already
in use in mines, not only for breaking ground, but also for
pumping and hauling. It resembles a gas engine, save th(^
the explosive mixture is produced by heating a spray of petroleum
and air. It is found that the consumption of ordinary mineral
oil is decidedly less than i pint per brake horse-power per hour^
reckoning the oil at 5 jd. per gallon, the cost of a brake horse-power
per hour is less than Jd. The danger which these machines would
introduce into some mines is self-evident, and they nre not fitted Tea
use in breakingground unless the workingsare of a nature to allow
tl^em to be moved about on rails. In the particular case of thethiek
bed of Cleveland ironstone, they are employed with advantage.
TRAITSHI8SIOIT OF FOWSB. — The generation power
in the working place itself is exceptional, and the problem
usually to be sotvea is how best to transmit the power of steam
or hydraulic engines at the surface to the machines employed
undergroui
Power is transmitted in mines in six difi'erent ways :
fl) By rods. U) By air.
(a) By ropes. (5) By waWr.
(3) By sUam. (6) By electricity.
Rods of wood or iron are chiefly employed in the case of pump-
ing machinery, and ropes in the case of hauling machinery, both
of which will be referrad to in later chapters.
Steam generated by boilers above ground, and conveyed by
pipes under ground, does not commend itself for driving machines
at the working faces in minesi. The drawbacks to its employment
are the Ices of pressure through condensation in the pipes, the
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1 64 ORE AND STONE-MINING.
inconvenieiice and danger of leaks, the discomfort of the heat,
and the trouble of the exhaust steam. The first defect ma^ be
considerably lessened by carefully jacketing the pipes.
There remain, then : sir, watOT, and electricity, all of which are
in actual practioU use at the present time.
Air.— The transmission of power by compressed air has the
immense advantage that the exhaust escaping from the machines
ben^ts the ventilation of the mine ; there is, on the other hand,
the drawback of considerable loes of power.
Mr. Sturgeon* eetimates that where the air is used without
re-heating and without expansion, the engine worked by the air
wiU develop only 31*9 per cent, of the power of the engine
oaed in compressing it. In some actual cases where the efficiency
has been tested practically, the lose of power has been far
mtdar thnn even the 68'i per cent. calculat«d by Mr. Sturgeon.
Professor Kennedy t found by experiments upon the transmission
of power by compressed air in Paris (Popp's 8y8t«m), that the
efficiency with cold air was 39 per cent, ; in other words, it i-e-
quired 2'6 indicated horse-power at the central station to produce i
indicated horse-power at the motor.
Air compressors are simply force-pumps, but the ingenuity of
inventore has been largely exercised in order to overcome the
shortcomings of the pneumatic mode of transmitting power.
Attempts have been made especially to combat the lose of
efficiency caused by the clearance fpacea and by the heating of
air when compressed. The effects of these two drawbacks are
readily understood. Suppose the piston of nn air-compressing
cylinder to have reached one end of its course, the air in the
clearance space on the compressing side is at the pressure piHi-
duced by the machine ; when the pibton reverses its stroke,
this air expands, and the admission v^ves will not open until its
pressure has been reduced to a point just below that of tlie
atmosphere. The first part of the stroke is therefore ineffective,
and the greater the clearance, the greater is the difference between
the theoretical volume of air, calculated from the diameter and
stroke of the piaton, and that actually delivered into the reservoir.
However, from a mechanical point of view, the power required to
compress the air in the clearance space is nearly all returned by
ite expansion when the piston changes its direction.
The loss of efficiency due to heating is felt in two ways : the
power expended in producing heut is wasted, and the hotter the
air the smaller is the actual quantity delivered by each stroke
of the compressor. This latter evil may be lessened by various
methods of cooling, and we are thus led to the following clas^ifi-
cation of tiir-compressors ;
• "The Birmingham Compressed-air Power Soheme." Paper read before
the Brilish AssocUtioD. Blrmfngham, 1886, p, 15.
+ Jiep. BrU. Aaior-., 1889, p. 45^-
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BREAKING, GROFND. 165
I. Water-column compressors.
II. Injection compreesors.
III. Dry compressorx.
I. Water-column Oomprea»ora.—Yh% machines of this class have
the advantage of using a cold surface for compressing, which
absorbs the heat of the air with which it is in contact. They also
get rid of the drawback of clearance or dead spaces, for the water
can be made to expel all the air at each stroke, and, lastly, there
cnn be no escape of^air past the piston. An eiirly form was that
of Sommeiller,* and Ang^tl■Om's t compressor, used with success in
Sweden in the infaouy of rock-drills, was one of the same type.
It consisted of two vertical barrels, connect«d at the bottom, and
each provided at the top nithan inlet and an outlet valve. The
barrels were filled with water in such a manner that the up and
down motion of the piston forced the air out or drew it in,
according as the column was being made to rise or sink. The
piston made only four strokes a minute.
Hanarte's compressor (Fig. 176), now employed in France and
Belgium, has a piston B travelling horizontally like that of Som-
Fic. 176,
m):iller, but tlie upright portions A A, instead of being cylinders,
are paraboloids ; C C are the inlet valves, and D is one of the
outlet valves. This arrangement allows a greater number of
strokes per minute, because the speed of the water diminishes
as it risee, although the speed of the piston may be uniform, and
also because the area of the cooling surface increases in proportion
to the amount of heating generated by compression. A Hanarte
compressor erected at Blanzyt ■" 1S87 could not be driven at
more than 2^^ strokes a minute, and gave some trouble from
frequent repairs of the valves. Like other machines of this class,
it also had the defect of dashing a little nater through tiie valves,
but on the whole it worked satisfactorily.
* FiearediD Hughes' Tixl-BeiA of Coal Minimj. p. 49,
t C. 1* Neve Foster, "An Acconnt of BergittBuiB Boiiog Mathine, now
Id use at the Pcrsbcrg Hiues, Snuden,'' Train, ifi'n. Attoe. ConuetdL and
Dtmn, 1867, p. 7.
X Mathet, L'air coaprtmt aux mnei dt Blanzy. Saint-BtieuDe, 1889,
PP IS- »4-
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i<6
ORE AND STONE-MINING.
IL Injection OompreMort. — In the injectioo compressors, water
is beine constantly introduced in order to absorb beat from tbe
air, ana at tbe same time it has the effect of partly or completelj
filUng up the clearance spaces, and of so still further contributing
to the effective working of the machine. It is either drawn iu
through the admission valves, or, better, it is forced in as a spray.
In a finely divided state it will naturally act more efficaciously in
a short time, which is of the utmost importance with a quick-
w<n'king compressor.
P^gore 177 represents one form of a Dubois and Vnn^is
injection compressor. A is the piston, B B are the two inlet
T&lves, and C C tbe two outlet valves. D D are pipes bringing in
water, ^hich is injected as a spray into tbe <^linder.
It has been found in many cases that, though the spray
■ndonbtedly has a cooling efiect, its use is coupled with the dia-
advantage that the piston and cylinder wear rapidly ; therefore
many engineers are of the opinion that it is better to put up with
« sUght imperfection in the cooling, than to have a loss of
efficiency through a badly fitting piston.
III. Dry ComprestorB. — Very many compressors are worked
tiry, and the air is cooled by its contact with the surface of the
■idea or ends of the cylinder, which are prevented from getting
hot by tbe circulation of cold water outside them.
Among the dry compressors may be mentioned that of Burck-
hardt and Weiss, of Bale, which was in favour at Blanzy* in 1889,
on account of certain advantages which it pOBseFsea over other
forms of machines, especially the great speed at which it can be
worked, the delivery of a dry air, and the auppresaion of the evil
caused by clearance. The benefit of a rapid stroke is that a small
machine, costing less money, occupying less space, more eattily
• Ifstbet, op. cil. p. 24. Forlher (ietaUs concerning this compressor
will be fonnd in a uimphlet iBSaed b7 tbe firm for thti ParU Exhibition,
1S89, snd in tbe Jlevue UnitrtritHe ih* Jllnei el Je la MHattvraie, i8Sq,
p.a79i 1890, p. ao2.
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BEEAKING GROUND. 167
transported, and more cheapljr eixcted, doea as much woik as a
large machine driven slowjy. Great speed of working is rendered
possible by effecting the distribution of the air by a slide-valve
worked mecbonically, instead of having valves which open and shut
automatically, owing to the difference of pressure on their faces ;
and the injurious effect of clearance is greatly reduced by bavin|;
a small passage in the slide-valve, which puts both sides of the
piston into communication with each other at the end of every
stroke. Consequently, when the direction of thepitton is reversed,
it at once begins to draw in air, instead of having the first part of
its course ineffective, as is the case with many compressors. It
must be pointed out, however, that the increase in the volumetric
delivery of air effected in this manner ia carried out at the "expense
of a certain amount of power. As already esplained, the power
required for compressing the air in the clearance space is not
entirely thrown away in the ordinaiy machines ; a part, at all
events, is stored up for a moment, and helps the piston in its
course OS soon ae the stroke is reversed. In the Burckhardt and
Weiss compressor this power is wasted. The cooling arrangements
of this machine have been very carefully studied. A curi'ent of
cold water is made to circulate not only around tlie cylinder as
usual, but also at both ends, a matter of importance, becuu.se it la
precisely at the ends that the heating is greatest, and that there
is the gieateet need of refrigei-ation. The piston and the slide-
valve are kept greased with oil delivered drop by drop from one of
Weiss's sight -feed lubricators.
Fig. 178.
The long experience of the Ingersoll-Sergeant Bock Drill
Company" has led them to adopt the conipreseor shown in Fig,
178. It has a double-acting air cylinder, with an iolet valve a on
each face of the piston. Fig. 1 79 is a perspective view of one of
* Saunders, Comjireued Air Production. New Tor!:, 1891, p. 22.
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ifiS
ORE AND STONE-MINING.
these ring-Bhaped valves. The compresaed air leaves the cyliader
hy the valves b b (Fig. 178); c e are groovee turned iu the eoda
of the cylinder which receive the projecting parts of the valves mi
the piston, and ho enable the clenrance to be reduced to a minimum.
The cylinder is kept coo! by the circulation
Fio. 179. of water through the spaces d and e, and,
save where there is the outlet valve, the
whole of each end participates in the re-
frigemtion by means of the water-jacketB,
d d. The action of the compressor is simple.
The air enters the piston by the tail pipe
whieh is attached to it, and, according to the
direction of the stroke, opens one or other (rf
the ring-valves leading into the cylinder. When the direction of
the stroke is rever>ed, this air is compressed, opens one of the
valves, 6, and passes out at/.
For very high pressuresit may be advisable to tise compound
mAi.-hines ; that is to say, machines in which the compression is
effected in two cylinders instead of one. The air is first partly
oompressed in a large cylinder, and, passing into a smaller one, is
bi-nughtto the required high pressm*. For the pressures ordinarily
used in mining, say 50 to 70 lbs. per square inch, compound com-
pressors are not, as a rule, thought necessary.
The usual type of air compressor used at mines is illustrated by
the diagram, Fig. 180. A A are the two steam cylinders, B the
fly-wheel, and C 0 the two air cylindei-s. It is Bometimes thought
Kiti. 180.
more economical to make the engine compound, and in that case
one of the two cylinders takes the steam at high pres-sure and the
other at low pressure, after it hiia somewhat expanded,
A point often neglected is the state of the air supplied to the
onmpressor. The Iiigei-soU -Sergeant Company are quite right in
insisting that the air should be taken where it is as dry, cold, and
fi'ee from dust as possible.
In order to secure uniformity of pressure and get rid of water
and impurities, the air is led from the compressor into a reservoir,
often an egg-ended boiler ; it should be provided with a safety-
valve, a pressure gauge, and also with a cock for letting off the
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BREAKING GROUND. 169
VKter which colloots g^radnally, eepeciaUy in the cose of wet com-
preesors. Sometimes a gauge is added in order to indicate the
h^ght to which the water rises.
Several uoderground reservoirs have been constructed at Maos-
feld.* One is a chamber lo m. long, i'5 m. wide,and 15 m. high
at the mouth, and then enlarged to 3 m. wide by z's m. hi^.
All loose stone was carefully removed, and the walls were plastered
over, first with cement, and then with a mortar made of equal
parts of cement and sand. A brick dam was erected in the con
tracted month of the bottle-like chamber, and in order to make it
thoroughly air-tight, a space 2 inches wide was left in the middle,
and filled up with cement.
The dam is provided with a diiiin-pipe, a (Fig. 181), just above
the floor, and a manhole pipe, b, 20 inches (05 ni.) in diamet^
clear; d and e are two of the four pipes taking the compi-eesed
-'^x
\ RE«t"VBia
..v.. 1
^&
ScALt
FLOoa
MCTKU
0-3 0 1
) ■ I . 1
'
*
S •
M FlCT
nir into tbe workings. Eath pipe has a strong cock, and the
manhole cover carries a pre«sure-gauge. Tbe drain-pipe a ia
ojiened at least once a day, to blow ofl the dirty water which arcu-
The underground resei-voirs have several advantages. In the
first place they cost only one-third of what they would have done
if constructed of sheet-iron ; secondly, they serve as accumulators,
and by storing up power make the machines far more independent
of the compregsors. Even if the compressor stops for a time, the
underground machinery cau go on working ; besides, when tbe
reservoir is at the surfa^'e, the machines nearest to it get a better
' Scbnder, "Dieneneren Fortschritte beiderAnwetiduDg vonGesteitis-
Bohrmaachiaen nnd die Versnobe mit kleinen ScbrftmrnaBCliineii b^m
Hanatelder KnpferscMeferbergbau,' ZeitudiT.f. B.- B.u. &- Wtien, vol ril,
1893. P- "9-
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l^o ORE AND STONE-MIKING.
supply than those at a distance. A third advantage ia the puri-
fication of the air, which deposite moisture, particles of dust, and
lutaioants. Lastiy, an underground reservoir cannot explode.
The compre^ed air of a surfaoe reservoir is conveyed into the
mine by mains. They are t^ten made of cast-iron with dange
Via. i8i. FiQB. 183 k 184.
M
joints of some kind. Fig. i8a gives the joint used by Mathet at
Blanzy for the pipes going down the shaft, which are 4^ inches
(120 mm.) in diameter inside. The joint is made air-tight by an
india-rubber washer, placed in the groove shown in the upper
flange, which is .squeezed tight when the two flanges are drawn
together by five bolts. The manner in which the pipe is sup-
ported in the shaft is rendered plain by Figs. 183 and 184 (the
dimensions are in millimetres). Croas-beama are put in at intervals
of about 100 yards, and the pipe is further kept in place by iron
clamps driven into the brick lining of the pit every 20 yards.
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BREAKING GROUND. 171
Meesrs. Kadie &. SoDBbave several jointa for lap-welded wrought-
iron and steel pipen used ia coDveyiag air, steam and water, ajnong
which may be epecially mentioned the one represented in Fig. 185.
In this case each end of the tube is turned up go as to form a
small flange, after a. looae ring has been alipped on. The loose
rings are made with spigot and faucet, which can bo drawn
together by four bolts, and thus made to squeeze an india-rubber
washer placed between the two pipes. Joints of this description
Are very easily and quickly made, and are found to remain ataunch ;
they, therefore, commend themselvee to the miner. The
lap-welded wrought-iron and steel tubes have the advantage of
lightness and oheapness, and as they are tested to at least 70a
lbs. per square inch they are fully strong enough to stand far
greater pressures than are met witfa in the air-mains of mines.
In America the line of welding is sometimes spiral instead of
longitudinal ; and in this conntry Rylands' glass-lined iron pipe,
3 inches in diameter intemally, has been chosen in one case for
the sake of lessening the friction.
The air- compressors furnishing supplies to the Chapin Mine,
Michigan, are situated at a distajice of three miles from the work-
ings, in order to take advantage of the Quinneaeo Falls as a sonroe
of power. The main leading from the compressors is a riveted
pipemadeof }-inch wrought-iron, 24 inches in diameter, in lengths
of 48 feet, and having expansion joints every ten lengths.
For branches conveying air from the mains to the actual work-
ing places, gas-pipe with screwed sockets is largely employed.
Finally, when the machine has to be shifted continually, thore ia
A piece of india-rubber hose, which should be covered in some
way, so as to prevent its being unnecesauily worn when being
dragged about over rough surfaces. Wire wound round the hose
odds greatly to its durability. Flexible metallic tubing has been
used with success in the place of india-rubber hose.
Water. — Force-pumps at the surface are made to drive water
through pipes to placcH underground where hydraulic engines are
worked by its pressure. They may be aided by an accumulator ;
that is to say, a cylinder into which the water is forced so as to
lift a plunger supporting a heavy weight, The accumulator
serves to regulate the load upon the engine working the foivie-
pnmp, and to store up power while the mining machinery happens
to be idle. It acts, in fact, like the reservoir used with an air-
compressor. A second method of utilising power at the surface
consists in drawing off water in pipes from the rising main of the
pumps. In both these cases any natural fall of the water adds its
effect to that produced by the engine above ground.
Hydraulic power has the great convenience, therefore, that it is
sometimes obtainable without any extra plant being required.
The water, after having done its work, runs out naturally if the
workings are above on adit, but has to be pumped up if they are
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172 ORE AND aXONE-MININQ.
below it. Uowever, it may b« cheaper and easier to work tiui
pump a little taster than to erect apeci&l atrKtompreeBing plant.
Hydraulic power has the diaadvantage, compared with pneumatic
power, of not ventilating the workings, and, as already pointed
out, <rf being objectionable with certain rocks.
Bleotrioity. — This method consists in driving a dynamo by any
available power at the surface, and then conducting the current
by wires to an electric motor underground. The possibility of
conveying power by wires is an immense con veuience to the miner.
The advantJigee, compared with transmission by air or water, are
that it is much eai^ier to fix wir«a than pipes ; viitee occupy moch
lesa room, and do not suffer like pipes from movements of the
rocks due to the workings. Like wat«r, but unlike compressed
air, electricity does not assist in ventilating the working pla^e,
and in fiery mines tiiere may be danger fi'om sparks.
Messrs. L. & 0. Atkinson, in spe^ng of electric transmission,
ill a very useful paper,* lately read before the Institute of Civil
EiigineeTK, say : " It wilt be seen that an efficiency of 67 per cent,
ciui readily be obtained even when transmitting nearly 100 b.-p.
to a distance of more than two miles, and without any attempt
being made to get specially good results, the whole plant being
such as can be worked by unskilled men."
The following table has been pi-epared by Messrs. Atkineon to
show the relative cost of transmitting power by compressed air
and by ele<tncity :
Electric .
Compressed ui
II
8
li
8
S
it
1=
6
li
1
1
■s
1
ill
1
£
£
£
7i 1
10 1 MOO
A in.
192
95 497 j 65%
4ius.
130
700
63 1 893 I 30%
Compared with compressed air, the plant is iesn expensive, and
tliere is the immense advantage of a smaller less of power in
transmission .t According to experiments made witli the electric
plant at St. John's Colliery, Normanton, and Llanerch Colliery,.
Mon mouth shii-e. the efficiency of the plant — i.e., the ratio between
* IVoc. Itut. Civ. Kiig., vol. oiv. SeBBion 1890 91, p. 89.
+ Suell, "nlcctiiuHl Trail Hmisaicn of Pover Id Mining Openitdons. ''
Paper lead before the LancaBhire Branch of the National Associatian of
CoTlicry ManagcTB, Wi^u, September sE, iSSg.
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BREAKING GBOUTiTD. 173
the work duu« in pumping and hauling b; the olectric motor,
and the work given out bj the steam engine at the surface — is
as much as from 43 to 48 % .
Making every allowance for the fact that these figures are
given by avowed advocjateB of electricity, it undoubtedly seems that
compressed air is at a disadvantage as regards cost and efficiency
wheD compared with its youngest rival.
A combination of electricity and compressed iiir has been
found advisable in some cases. The power is transmitted uader-
gronnd by electricity to motors which drive small air-compreeaors
placed in the vicinity of the working places where percussive
drills are required.
Hitherto the priiiciptd applications of aleL-trical transmitting
plant have been for pumping, winding, and hauling, and little
has been done in the way of machines for breaking ground ; but
rotary and percussive drills driven by electricity are already
beginning to be employed.
BZCATATUTa HACHIITEBY.— The machines used for
excavating may be classified aa follows :
(3) Drills for borlDg boles for blasting or vradglng.
'.4) Machines for cutting grooves.
(S) Machines for excavating complete tnnnels,
I. Steun Digger. — The steam navvy, though specially the
machine of the railway or canal engineer, must not be forgotten
by the miner, who has to ezcavute large quantttiee of com-
paratively soft deposits near the surface, or to remove overburden
such as sand, gravel, stiff clay, or chulk. After a preliminary
shattering hy bliisting, even hard rock may be shovelled up by
these machines.
Amotigthem we may mention i>un^ar tt Riiaton' a Steam Navvy*
(Fig. 186), largeiyusedinmakingthe ManchesterShip Canal. It
is a steam crane which brings a bucket, armed with teeth and a
sharp edge, against the side of the excavation, draws it up and
drops its contents into a railway waggon. The iigiu'e needs but
tittle explanation. A is the vertical boiler giving liteiim to two
cylinders, one of which is shown at B. TheBe ure made to work
drums for raising and lowering the bucket 0, by the chain D,
<Mr for turning the jib Q.
In order to work the navvy the bucket is lowered till the
handle E is vertical ; it is then brought against the bottom of
the working fac^ and drawn up by the chain D ; the teeth
enter the earth and open the way for the cutting edge. The
buAet fills itself, is swung over the waggon bj the jib, and
■ Mining Journal, vol. Mil, (iSJtSJ, p, 1241.
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174 ORE AND STONB-MINIKG.
emptied by pulliag the cord H. It closes automatical]; when
lowered.
The depth of the cut dependii upon the length of the radius given
to the circular arc described hy the cutting tool. The radins,
and therefore the cut, can be altered by a maa, standing at the
foot of the jib-poflt, who works the chain F ; this actuates a
pinion geariog into a rack upon the bucket handle E.
The navvy requires three men, one attending to the raising
and lowering of the bucket and swinging of the jib; a second
regulating the depth of the cut and the discharge, and lastly a
Fig, 186.
fireman. £uch bucket containti i to i ^ cubic yards, and
three buckets will fill a contractor's wag^n. In ten houra this
machine will excavate and load from 700 to 1000 cubic yards of
earth.
When all the earth within reach has been excavated, the jack
screws are loosened and the machine made to propel itself forward
on the rails a few feet.
A somewhat similar machine is WUgon'i Steam Crane Excavator.
It is a 10 ton steam crane to which a digging bucket can
speedily be attached. The machine can therefore be used as a
crane or as a digger, as occasion reijuirefl.
Thia is also possible with the Wkittaker Excavator, which, like
the two previous steam uawies, has been used for making the
Manchester Ship Canal.
Steam diggei-s are much used by miners and quarriers in the
United States, and especially the machines made by the Marion
aud the Bucyrus Steam Shovel Companies, which iu principle
resemble the Dunbar and Buston Nnvry. The Earnhardt Steam
Shovel of the formei company is employed iu the Mesabi Range,
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BREAKING GROUND. 175
Hinn., and in other places, for stripping off oTerburden and for
excarating iron ore, and the Bucyrus Company applies its digger
with BuccesB to auriferous ginvel, instead of washing it down by
the hydraulic process.
Besides serving as true excavatiag machines, the«e steam
shovels are found economical for loading ore h^m stock piles into
railway vraggons.
Another kind of digger may be spoken of as a dry 'Iredffe ; a
machine of this class, made by a Ltlbeck Company,* is in use,
among other places, at a large openwork where brown coal is
being worked near Briihl, between Bonn and Cologne. The
excavating part of this steam digger coneists of a long arm with
a chain of buckets, like those of a dredge, which are brought
ancceBsively against the face of the overburden and then carry the
gravel into a hopper ; side-tipping waggons are run under this
hopper and quickly filled by opening a door.
The pulley which makes the endless belt of buckets revolve is
set in motion by friction gear, so that there is no fear of a break-
age, even when a bucket comes against some veiy hard place in
the overburden which it cannot penetrate. The arm carrying the
buckets can be raised and lowered as required.
Theoretically this machine will excavate 1000 cubic metres
(1300 cubic yards) in ten hours ; the actual work is stated to.be
about 700 cubic metres (915 cubic yards) in that time.
The Bucyrus Steam Shovel Company likewise makes a machine
of this type.
II. DredgeB. — The beds of rivers and lagoons, and even sea
beaches and bottoms, sometimes contain minerals which can be
excavated by dredges like thoee used for improving harbours.
There are three types : —
(1) Bucket dredges.
(2) Grab dredges.
(3) Sactlon dredges.
I. Bucket Dredges. — Kincaid & McQueen'H machine (Fig. 1S7),
used with success upon the Molyneux river,t New Zeahuid, is a
big barge, 66 feet long, with an endless chain of buckets and a
pontoon on each side. The total width of the barge and two
pontocms is 36 feet.
The buckets Aitt worked by a steam-engine upon the barge,
which also drives a cylindrical screen for separating any large
stones. The engine is a vertical inverted compound steam-engine,
with eylindera of 13 inches and 32 inches diameter respectively,
and 18 inches stroke, working at a pressure of 60 lbs. per square
* " LObecker U aROhlnenban OescUachaft."
t .Viiut fUatement. By the Hiniater of Uioea, the Hon. VT. J. H.
Lnmacb, C.M.O. Delivered Jalj 6. 1S86, p. 17.
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i-j6 OKE AKD STONE-MINING.
■Qie bucketo can be made to raise as much as 150 tons of stuff
per hour, and to excavate to a depth of 35 feet below the level of
the water. A steam winch serves for niising and lowering each
of the dredging ladders, or frames, carrying the endless chains of
buckets, and aho for working the mooring chains.
A dredge of a similar kiud has been used on the river Oreo, in
Piedmont,' for the purpose of excavating an auriferous alluvium
in order to extract gold from it, and with the further object of
preventing floods by straightening the course of the river and
* embanking it.
The dredge has an engine of 50 b.-p., and is said to be capable
of raising 3200 cubic yards of aliuvium (3So<=> cubic metres) in 22
hourv. It can excavate to a depth of 36 feet (8 m.).
2. A yrai dredge consists of a single hemispherical or semi-
cylindrical vessel, which is made so that it opens when lowered,
fills itself on touching the earth and closea as soon as it ia raised.
The raising and lowering are done by a crane. The semi-cylindrical
bucket may be armed with teeth ; it descends with the teeth open
and is drawn up with them closed.
Bruce ii Batho make some of their grabs with three or four
sharp blades, like very pointed spades, which close upon being
lifted, and form a hemispherical bucket. A somewhat Mmilar
grab dredge has been employed for stripping ofl* the overhunlen
from a bed of aariferous gravel in Califamia.t
The Priestman Grab dredger has been used for excavating the
* OuzaUaili Torino. Hay 11, 1886.
t Eighth Anaaal Sijmrt of the State Minerah-gi'l, fur Ihe year iSSS.
SacTanMmto, 18&S, p. loa.
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BREAKING GEOUND. 177
auriferous gravel of the river Nechi and its tributaries in the
United States of Colombia {Fig. 188), and it likewise serves as
a digging machine on land, and even for sinking shafts.
3. The Suction dredge may be described very shortly as a cen-
trifugal pump arranged to draw up sand and gravel with the
water. It is placed upon a barge, and the suction pipe can
be lowered, raised, or moved from one side to the other, so as
to attack any part of the sea or river-bottom. A Wslman
dredge of this type,* used for excavating the ocean beach at the
mouth of the Waipapa Greek, has suction and delivery pipes 12
inches in diameter. It appears to be doing excellent work where
the hulk of the material to be treated consists of sand and fine
shingle. The beach is reckoned to yield about 3 grains of gold
per ton, whilst the working expenses are ooly 2 grains per ton.
III. Book DrUla.— Most of the machine drills have a per-
cussive action, but a few are rotary ; for Stapff pointed out some
years ago that if a rock may be chipped off by power communi-
cated \)y a blow, it may also be chipped off by a similar amount
of power oommunieated by preesure.
I, Botaiy Drillfl. — Following the order I have adopted in
liDgton, 1890, p
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178
OKE iND STONE-MININa.
the case of the hand tools, I will firat speak of the rotary
machines.
BrancU'a rotary driU consists of a hollow borer which has a
steel crown, with cutting edges, screwed on. The tool is kept
tight against the rock by the pressure of a column of water, and
is at the same time made to rotate by two little water-presGure
enginea, whilst a stream of water passing down through the
borer washes away the chips and eand, and keeps the cutting
edges cool. In principle, therefore, this drill resembles the
original diamond boring machine of De la Boche Tolay and
Ferret, save that the crown is made of steel and not of diamonds.
It has been used with success in railway tunnels and mines.
Brandt's machiue was worked at one of the mines at Freiberg*
in Saxony, with water at a pressure of 83-5 atmospheres, of which
566 atmospheres were obtained by pressure pumps provided with
an accumulator, and 36'9 atmospheres by natural fall, owing to
the level in which the machine was used being 377 metres below
the pump. The wat«r was conveyed to the pump in iron pipes
ij- inches in diameter inside. The diameter of the holes
was 2 1 inches, and they could be bored in gneiss at the rate of
I J inches per minute. The streti^er bar on which the machine
is carried is hollow, and has a piston which can be f<H^:ed out by
hydraulic pressure so as to fix it firmly. A similar bar is some-
times used with percussive drillat
Comparative experiments were made at Frdberg between this
drill, hand-labour, and a percussion drill, and the results given
below are of much interest and importance. In the case of the
two machine drills, the cost includes interest on and depredation of
plant, repairs, and the estimated expense of providing steam
power, which would have been neceasuy if water power had not
been available :^
Hud boring.
Schrtm-i
drill.
77-4-85 as
3-48-3-66
Bnndfi
drill.
Difitacce driven per week in
metres
Coi-t in marks per metre driven .
Wayes realUeS by the miners in
marks, per elght-houn shUt
0-9S
no-134
i8s-a-os
5t»
74-J*
376
The benefits of machine work are very marked indeed, both as
ivgards rate and cost of driving, and wages earned by the men.
Brandt'tt rotary drill did its work cheaper and faster than
Scbrum's machine ; but nothing is said in the original notice of
* Jahrbach filr dot JBtrg- und HstUmcettJi im KSnigrtuAt Sadufn anf
da» JaKr iSSi, p. 18.
+ 4nn. Minet. Ser. S, vol. il. i88z, PL I., Fig. 6.
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BREAKINa GROUKD. 179
the advantage of a. nmchine driven by compressed air for venti-
lating workings, such as advanced headuiga in which these drillii
are employed.
In JarolimieJ^s* drill the borer is hkewise a rotating tube -
armed with steel teeth, but it is fed towards and pressed against
the rock by a differential screw arrangement. Water passing
through the hollow borer keeps the teeth cool and carries away
the dibriB. The machine can be worked by hand, but a little
water-pressure or oompressed-air engine, or an electric motor will
be preferable.
Experiments have been made lately at Zauckerode,t in Saxony,
with a diamond drill for boring holes for blasting.
The machine is a steel tube with a steel crown screwed on, con-
taining four black diamonds ; it is driven by a small electric motor
upon a carriage on wheels in the level, by means of a shaft with
two universal joints. This arrangement allows holes to be bored
in any direction required for driving the tunnel. The holes are
from I' I inch to i'3 inches (28 to 34 mm.) in diameter.
The result of the experiments is that in hard clay-slate with
numerous veins of (juartz, or in gneiss, granite, or rocks of similar
hardness, a level can be driven nearly twice aa fast as by hand,
and at about the same cost.
It is also possible to attach a motor of some kind to a tunsf
• Ottt. ZeUtdiT.f. B.- «. Jf.Wt»en,va\. snx. (1881), p. 184; andvoL
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i8o ORE AND STONE-MINING.
drill similai' to Elliott's hand tool already described. The Jeffrey
MaBufacturing Company, Columbus, O., have well-designed drills
of this class driven by air or elec-
tricity.
For working the Cleveland iron-
stone, Mr. Steavenson* is employing
twist drills driven by watei^powsr,
petroleum engines or electricity. Bin
latest drill is shown by Pig. i8g : A,
electric motor; B, hollow arm witli a
shaft inside driven by A, and work-
ing the bevel wheel C by suitable
gearing ; D, twist drill ; E, socket for
drill; F, universal joint connecting
the feed-screw G, to the drill-socket;
H, feed-nut. Fig. 190 is a similar
drill worked by a Friestman petro-
leum engine.f
The cost per ton of getting the
Cleveland ironstone has been greatly
reduced by the adoption of tbeee
machines in the plnoe of hand-labour ;
^ but, as is usually the case, the cost of
■ explosives per ton of stone broken has
h easily and quickly that lees care ia
taken in planning them. The extra
cost of powder b more than repaid
by the saving in labour.
The Sprague Electric Bailway and
Motor Company of Now York t have
a small electric rotary diamond drill
for boring holes for blasting. The
motor is light and carefully cased in to
preserve it from dust and dirt ; it ia
mounted upon an adjustable stretcher
bar, and it drives the drill direct.
2. FerouBSive Drills. — Machine
drills are usually designed with a
view of carrying out the three opera-
tions of hand -work— viz., the blow,.
* Steavenaon, " On tha System of Work-
ing Ironatone at Lnmpsey UiDes by Ht-
dnLolic Drills," l\v>c. if.E. Imt. M. and M.
Eng.. voL K).vi. (1886-87), p. 67.
t Unwin, " Fetroleiun EngineB," Proe. liul. O.E., toL cik. (1891-92),
putiU.
X Eng. Hin. Jour., vol. xlii. (1890), p. tii.
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BREAKING GROUND. i8i
the rotation, and the advance. As a rule a percussive drill conssts
of a cylinder with a piston, which is moved Ukckwarde and forwards
hy compressed air ; the cutting tool or chisel is firmly attached
to the piston rod, made specially strong to stand the great amount
of shock to which it is subjected. The rotation ia almost always
effected by a twisted or rifled bar and a ratchet wheel ; and, in
order to keep the machine constantly in the proper position for
work, it is fed forwards upon a cradle by the workman behind,
who has merely to turn a handle, and so cause a screw to revolve
inside a big nut attached to the machine. Drills which will
advance automatically have been invented and used ia some
cases, but as a rule nonadays the automatic feed has been
l^ven up ; indeed, it seems quite unnecessary to increase the
uomber of the working parts and make the machine more com-
plicated, simply to save the attendant the trouble of turning a
handle.
Though the plain chisel-shaped edge is the commonest form
given to the bite used with machine dnlls, it is by no means am-
versal ; other foims shown in the figures are the cross-bit, the
, Fig. 191. Flo. 193. Fia. 193. Pig. 194.
X-bit, the Z-bit, and the hoi'se-shoe bit (Figs. 191, 192, 193, and
194). The object in all cases is to secure a perfectly round bote
and BO prevent jamming. If a baud of hard rock crosses a hole
in a shuiting direction, the pingle-edged bit is apt to be diverted
by it slightly, and become fast. At the outset also, when the
drill is striHng an uneven surface, it is not always easy to bore
the hole properly ; for this reason the first drill is sometimes
made with the cross-bit, whilst the remainder of the hole is bored
with the single chisel-edge, which will work properly when the
bole is deep enough to act in some way as a guide for the tool.
Sits with two or three edges are not so easily sharpened as
those which have but one ; however, the work of the smith may be
lightened by using a swage {dolly, U.S.A.), which is, practically,
a steel mould, into which one end of the steel bar is placed when
soft, whilst blows are struck upon the other end. This gives the
proper shape, and the smith can finish up the bit upon the anvil.
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i8j orb and aiONE-MINING.
The adoption of the ingenious-shaped bars of the Crescent Steel
Company of Chicago (fig. 195) will likewise relieve the smith, but
tiie saving of labour at the forge is
Fio. 195. not the only advantage claimed for
the inrention. The shaped steel will
discharge the debris more freely than
round steel, a matter of no slight
importance, for the cleaner the hole
the more effective the blow ; the little
chips should be got rid of as soon
as possible, and any means of facili-
tatang the discharge should be welcomed. A represents the
pattern made originally for the iron minee of I^ke Superior, and
B the section preferred in the Bocky Mountains.
Loon sharpening is required when boring by a machine than
when boring the same depth by hand, and for two reasons : first,
the bit sn&rs less, because the blow given by the machine is
straighter and fairer ; and secondly, owing to the greater farce
of the blow work can be done by the tools when they have become
very much blunter than those which would be put aside in hand-
driUing. For machine-drilling in soft sandstone in Ohio, the
borer is made with a narrow hut perfectly flat hit, instead of being
chisel-shaped. A flat-ended borer is likewise used by the Inger-
soll-Sergeant Bock Drill Company for boring elongated holee by
the Githen system. The tool does not rotate, and acts by pound-
ing the bottom of the hole to dust. The object of the elongated
h(de is to make the rock rend along a pre-arranged line, a matter
of importance in quarrying certain kinds of stone.
Percussive drills may be classified according to the power used
for driving them, and those worked by air may be further sub-
divided according to the kind of valve emplc^ed for revendng
the direction -of the stroke.
The following table contains a list of several well-known drills,
arranged according to their mode of action and alphabetically : —
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BBEAKINa GROUKD.
FBBCDsaivK Drills.
N«..oftb.
f
Barrow
aimax
{!) Va]M worked by mechanical '
DnboiB and
t
(
Franfois
Holman
Rand
RioTiDto
BIckle
(2) Air-driTen valve . .
1
Colea
EclipM
OptimaB
Compnssed air
Franke
Him ant
H) Two nlTM, & main one air-
driven, and an anzUiary one
Sergeant
tions
i
Adelaide
(5) No valve .... J
Darlioeton
Minora
Electricity . .
Marvin
Fot the purposes of this work it will be quite sufficient to de-
scribe only a few of these machines, eepecdaUy as in many
instances there is a great similarit]' between them.
(i) The Bamv) driU* (^^- '9^) onsista essentially of a gun-
metal cylinder C, about 2 feet in length and 4 inches in diameter,
in which works a cast-steel piston-rod D, fitted with two
pistons O, about 12 inches apart, midway between which is the
• Geom Seymour, " On tlie Barrow Bock Drill," iVoc. iftti, Ttul. Oam-
HMtR, voLl (1876-S3), p. 12.
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i84 ORE AND STONE-MINING.
tappet or boss G'. lu a valve-box at the top of the cylinder is
placed the oecillatiiig slide-valve H (shown separately), pivoted
at M ; it is worked by the reciprocation of the tappet G'
ooming in contact with its lower edges, which, for this purpose,
are sloped at each end, as shown.
There are ports, corresponding with openings in the slide-valve
face, for admitting the fresh steam or compressed air from the
inlet pipe I (Kg. 197) to the portsj (Fig. 196) at each end of the
cylinder, and for letting the spent or exhaust air or ateam escape
by the exhaust pipe J (Fig. 197). This simple arrangement con-
Btitutes the whole valve gear of the machine.
" The borer is inserted into a hole formed in the fore-end of the
piston-rod, and is fixed therein by means of a screw. Its rotation is
effected by hand hy means of the handle D" turning a spindle D',
Fig. 197.
which is so fitted by means of the cotter d, made fast in the piston
DO, and fitting in a slot in the spindle D', that the latter can
slide in the piston IXr, but when turned by the handle causes
the piston to turn with it. The spindle D' has a pinion E, gear-
ing into a pinion on the adjusting and feeding screw C, so
that when the piston D is turned by means of the handle D", the
cylinder G is simultAneously pushed along the bed-plate A. These
pinions can be easily disconnected by loosening the nut /, and
thus the piston and the adjusting screw can be turned inde-
pendently of one another when required.
" The borers used are respectively i^, ij, and 1 inch in diameter,
the length of the stroke 4 inches, and the maximum number of
blows about 300 per minute.
" The gross weight of the machine, including the bed-plate and
gudgeon, is about 1 1 5 lbs.
" The bed-plate. A, of the machine is formed with a gudgeon
A', which fits into and can be adjusted to any position in asocket
formed in or on a clamp B', which can be fixed on any part of
the wrought-iroa box or column B, thus forming a universal
jidnt. This bar or column can be placed in position either
h<«izontally or vertically, as may be most convenient, but is
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BREAKING GROUND. 185
generally placed acroee the level, against the aides of whicli it ie
secured by means of the damp L, adjusting screw M, and claws
N and N'." Pieces of wood 0 0', are placed against the wall,
and the claw is jammed against them by screwing out the bar.
The Climax Drill* (Fig. 198) recalls the Barrow ; A is the
cylinder, B B are the two pistons, and G the boss or swelling which
strikes the valve I> and rocks it up and down on the centre pin K.
The valve has two admission ports, F and F, which, when passing
corresponding porte in the valve-chest face, allow the compressed
air to pass into G or G'. On the inner face of the valve, above F
and F, there are two recesses, precisely similar to H and H',
whicb control the two ports on each side of the valve-chest face.
In the position shown in the figure, the compressed air could pass
from the valve-chest through F' into G' and drive the piston
Fio. 198.
forward, whilst the air in the front part of the cylinder would
escape by G, which is now put into communication with the
exbanst port by the recess above F, The object of the two recesses,
H and H', is to enable the valve to be reversed when one face is worn.
The rotation is effected by a rifled bar I at the beck end of the
cylinder, which projects into a long cavity E in the rear piston
and piston rod. It can be turned easily in one direction, but is
prevented from moving in the opposit« direction by the teetb of a
crown ratchet clutch L, a device which is thought by the maker
to offer a better guarantee against injury than the ratchet wheel
with one or two pawls common in most other drills. When the
* Figures and deBcriptiouB of the BicUe, Climax, Coles, Daw, Eclipse,
Iiigfln<d], and Rio Tinto drilU will be found in a paper b; Carbntt and
Daver, " On Recent Trials of Bock Drills," 3lin. Aoe. Init. iUch. Eng.,
LoniJoD, March 1891.
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i86
ORE AMD STONE-MININa.
piston icoves forward, the nut in the rear pisttm passes over tlie
rifled bar, and causes it to tmii round, but when the motion
of the piston is reversed the rifled bar is prevented from turning
by fche ratchet clutoh, the piston is forced to rotate, and with
it the borer. M is the feed-acrew worked by a handle not shown
in the figure, and N the feed-nut.
The Duboia and Franfoit Boring Ratn {Boaieyeiue)* is a maciiiiie
of a totally different type (Figs. 199 and 300); it bcrea large holes
for the insertion of a wedge, and it is fitted with a nun for driving
is the wedge, and so breaking the rock.
3^ tnacbine has been specially designed for driving levels in
mines where there is eo much fire-da!mp ss to render blasting
Fias. 199 & 3oa
S5555^S^S5S?^
dangerous, and it therefore more especially concerns collieries
than ore and stone mines ; but it should be mentioned in connec-
tion with the latter, because it will also bore holes for blasting,
and because it is sometimes used for cutting a series of boles, and
BO creating a first opening, which enables blasting to be conducted
with greater advantage (Fig. 239).
The boring cylinder. A, has a long piston B, with spiral grooves
which produce the rotation by means of a ratchet wheel C, whilst
the slide-valve, which efTects the distribution, lies in the valve-
chest F, and is brought into action when a swelling, D, on the
piston-rod touches a bent leyer E.
The borer, G, is fixed in the end of the piston-rod, and makes
n bole 3 or 4 inches in diameter. As the bole is deepened, the
* Uathet, L'air coniprim6 niw mitut dt BUmzy, Saint-Etisime, i8S9,p. 66.
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BBEAKINO GEOTJIfD. 187
(^linder is made to travel along the frame, H, by meana of
ft sorow, and at the same time the counterpoiae, I, is also moved
by a screw BO ae to balance it. The machine can be made to turn
round the central oolumn, and can also be moved in a vertical
plane, so that holes may be bored in any direction ; and the
special carriage in use at the Blanzy mines permits the machine
to be moved laterally, and taJ^e a position near the side of the
tiuinel.
The whole machine is very heavy, weighing no less than 2 tons
13 cwt. (2700 kil.); but it is found thai the greater power and
stability so obtained fully compensate for any inconvenience
caused by its weight.
At Blanzy one boi-ing ram has taken the place of four small
drills mounted upon one stand ; and this diminution in the
number of machinea requiring attention is no incocaiderable
advantage.
An ingenious contrivance used with the Blanzy boring ram
must on no account be passed over — viz., the special pipe for con-
veying water to the bottom of the bore-hole. A small copper
tube (L, enlarged croes-aection, Fig. 300) lies in a groove in the
borer, and carries in a jet of water which keeps the bit or boring
edge quite cool, and washes out all the chippings as soon ss they
are produced. The tool is thus enabled to work fairly and freely
the whole time, and the result at Blanzy has been a great increase
both in the speed of boring and in the duration of the hits.
The water is supplied to the drill by the india-rubber pipe J,
which leads to the hollow collar K. The collar is fixed with a
water-tight joint upon the drill socket, so that the latter can
revolve freely. The water finds its way through a hole in the
drill-socket to the outside, when a short piece of india-rubber
tube takes it to the copper pipe. The collar is kept in one posi-
tion either by a weight hanging down from it, or by a rod which
moves forw^da with the machine. Care is taken to pass the
supply of injection water through wire gauze, to remove any
mattw which might choke the small copper tube.
When the necessary holes have been bored, the drill is taken
ofi'and replaced by a strong t&m or hammer-head, which is made
to strike powerful blows upon a wedge between two feathers
fitting into the hole. Large masses of rock are broken ofi* in
this way, and the level is driven with any required dimensions.
(3) The AmBntxa Ingeraolt Sergeant EelipaeDriil {Fig. 20j) may
be taken as an example of the machines having the valve worked
by differences of air-pressure, which are caused by the opening and
closing of certain passages by the piston in its course. It cdnsists
of the following main ports : the cylinder A, the piston M, the
piston-rod B, and the valve chest C. The valve is like a D-sUde-
valve, but its face is turned so as to fit the cylindrical interior of
the valve-chest, and it is provided at each end with a piston. It
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i88 ORE iND STONE-MINING.
therefore has the form of a spool or reel enclosing a D^de-valve,
and it moves backwards and forwards on a guide-pin. The air
enters the valve-chest at O, and, when the piston has reached the
pomtdon shown in the figure, it finds its way round the valve to
N', enters the port F", and finally reaches the rear end of the
cylinder ; when the valve is reversed, it goes past N into F, and
to the front end of the cylinder. The port P ia shown in the
figure communicating by the slide-valve with the exhaust £.
The letters 8 S' represent a shallow recess cut round the
piston, in reality making one piston into two ; F W are two ports
leading to the exhaust, and lastly D D' are two small ports which
communicate crosswise with the ends of the valve-chest; that
is to say, D is connected with the end R', and D' with the
end R.
Bearing these details of construction in mind, the action of the
drill can be followed. The drawing shows the machine ready to
begin its forward stroke. The rear end of the valve-chest is con-
nected with I>, which is cloeed by the piston, whilst the front K
ia open through D" and the annular recess S lo the port I" and
the atmosphere. The compressed air from O leaking past the
rear valve-piston presses upon it and keeps it in the position
shown, for any air leaking past the other valve piston at the end
R can escape vid IV, S, F and E into the atmosphere.
We will now suppose that the main piston M is being driven
forward by the pressure behind it ; the annular space S gradually
approaches the port D, but the length of the groove is soarranged
that D' becomes closed juat before D ia opened to the exhaust.
When the new state of things has arisen — that is to say, when D ia
open to the exhaust and D' closed — the pressure in the space R'
at once drops to that of the atmosphere, and the valve is driven
across by the pressure upon the piston at the end B.
At both ends of the cylinder there is a strong india-rubber
washer, protected by a steel washer, which ia represented by a
black line. If the miner fails to feed his machine forward pro-
perty, the elasticity of the washer prevents the end of the cylinder
from being broken. The rotation is performed by the usual
Dded bar and ratchet wheel, and the machine is advanced by
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BREAKING GROUND. 189
turning the h&ndle and bo causing the carrying nut to ijiove
along She feed screw.
The Optimue driU, mveoted by Ogle, has two pistons, a large
one in front and a small one behind. The comprised air, after
acting at the rear end and making
the tool Htrike its blow, U led to Fios. soa & 303.
tiie front end of the cylinder, and
presBing upon the large piston
drives it back. The inventor claims
considerable economy for his drill,
because the backward stroke is made
with air which usually goes direct
to the exhaust.
!E1gB. 203 and Z03 show one
method of attaching the drills to
the piston-rod, A is the piston- . .f ■^ t
rod with an enlarged head, H; S is iHcnEa
the shank of the tool which is
gripped in the socket by a chucking- block B, tightened by a
U-shaped clamping-bolt 0.
(3) /Vani« thill.* This drill {Fig. 204) is espeoially interesting
from being the smallest and lightest boring machine in actual use.
Including the borer, it weighs only 16 lbs. (7^ l<il.), and it may,
therefore, be placed at one end of the scale wbilat the ponderous
"bosaeyeuse" of Dubois and Francois occupies the other. Both
in his drill and in his mechanical chisel, Franke adopts the prin-
ciple of doing the work by a light blow repeated very rapidly
indeed, instead of a heavy blow at lees frequent intervals.
The principal parts of the machine are : — A, outer case or shell ;
A', cylinder proper; B, piston; C, ring^baped slide-valve, which
can wde backwards and forwards in a Bhort recces in the piston ;
D, tool-holder; B, pipe bringing air; F, rear end of cylinder
proper with admission ports ; 0, spiral spring ; ff, exhaost
port ; /, piston-rod ; •/, striking head of piston-rod ; P, pin passing
through the piston-rod; a, passage bringing air from F^ b, port
admitting air to slide-valve ; c, one of three longitudinal passages
connecting the front end of the piston with the annular recess
in which the slide-valve works ; «, one of three similar passages
connecting the same recces with the rear end of the piston;
fi hollow centre of piston and piston-rod communicating by g with
the exhaust port H ; hh, two of the three radial passages which
put the slide-valve (7 into connection withy*; i, part of tool-bolder ;
j, collar preventing the tool-holder from being driven back too
far ; I \, straight slots in the shell A; oo„ oblique slots in the
* Schroder, "DieneverenFottBohTittebetderAnwendDDgvon Oesteins-
BohimaachtDeu and die Veraaohe mlt kleinen Scbr&mmaschinen beim
HansfelderKupferBcbleferbaigbaD," Ztiittkr. f. B.- H- u. 8.-Wuea, vol.
JdL, 1893, p. iio.
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190 ORE AilD STONE-MINING.
hollow cylinder q; q„ end of the cylinder q ; rr,, ends of the
pin P; tt, pawls attached to g, ; u, hexagonal end of the tool-
8 IS
i ^
holder I) ; v, ratchet wheel, which can dide upon u but cannot
rotate without it.
After this description of the parts, the mode of action of the
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BREAKING GROUND. 191
machine can be easily understood. The air is brought by a flexible
boee attached to E, and passing along the small passages a outside
the cylinder proper, entws it at h. In the position shown in the
figure the lower h allows the air to pass into 0, press upon the
rear end of ths piston, and drive it forwards. During ttus time
the air in front of the piston has an escape provided by the passages
C A, /, and g to the exhaust port H. The complete stroke is
20 nun. (^ inch), and when the piston has travelled 17 mm.,
the end of the piston rod ./ strikes the head u, and the tool
does its work at the bottom of the hole, provided of course that
the machine is properly held. As the piston goes forwards it
draws the slide-^ve G with it ; as soon as 0 has passed the port
b, it is driven across the recess and the direction of the air is
reversed. The front end of the cylinder is now in communication
with the compressed air, whilst the space at the rear end dis-
charges its coQt«nte vid e, C, h, /, and g into M. The slide-valve
0 is then again shot across, and air is admitted to the rear end of
the piston. The end of the piston-rod, J, is therefore constantly
hammering upon u, and after each blow the spring G brings the
tool-holder bock to its original position. The rotation of the tool
is effected in a simple manner. The ends rr, of the pin P ttre
forced to travel in a direct line by the slots II, ; but the slots oo.
are oblique, and the pin P, therefore, causes the hollow cylinder q
to oscillate. During the forward stroke each pawl, (, is drawn
over a tooth of the ratchet wheel v ; during the back stroke it
turns V slightly, and with it the tool-bolder.
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igi ORE AND SXONE-MINING.
The borer is made of round ateel § inch {15 mm.) in diameter,
with A Z-shaped bit i ioch (35 mm.) wide. The number of blowB
I I has not yet beea determined
exactly; but it probably
! reachee 8000 to 10,000 per
minute. The moving parts
of the machine are constructed
of soft tough steel, except the
elide - valve, for which good
wrought iron appears at present
to be the most suitable material.
The machine is used without
any atand, and is simply held in
the hands (Fig. 205, man in &
kneeling posture).*
The ffimarU drUlf of Meesrs.
Larmuth & Co. is a machine with
a tappet valve assisted by air-
preesure. In Fig. so6, A is the
cylinder, B the piston, and C
the valve-chamber containing a
piston- valve J), which works over
« the admission ports E and £',
« and the exhaust porta F and I".
g (r is a tappet, oscillating upon
h the pin 3, when the noees / and
K are struck by the curved
shoulders L and Jf of an
annular recess ^ around the
piston £.
In the position of the parts
as figured, the compressed air
brought into the valve-chamber
is passing through J-" to the rear
end of the cylinder, whilst the air
in front is in communication by
E and F with the exhaust. At
the same time the air is also
pressing upon the rear end of the
piston-valve, for it escapes along
the passage ffP' made by planing
flat surfaces upon the valve and
the inside of the end of the cham-
ber. The other end of the valve
* From a photograph snppUeid by the makers, Mrasrs. Friemann and
Wolf. Zwickau,
t Patent Office Specification No. 10,050, i.D. 1891.
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BREAKING GROUND. 193
chest is put into commnnicatioii witli the exhaust by the small
port Q, and as the flat eurfaoee P and 0 are not overlapping,
there ie no passage of compressed air. The pressure upon the
rear end rf the valve D tnerefore
tends to move it forvardH, and asfiisti>
in moving it forwards, the moment
that the nose 7 can drop down owing
to the recees N passing iinder it. The
shoulders L and M would of them-
selves move the tappet, but the
auxiliary air pressure has the advan-
tage of reversing the valve without
the shocks which are so destructive
to the tappets of many drilb. The
cushion of air in the space R' pre-
vents the nose K of tiie tappet 6'
. from striking the recessed pai't i'
of the piston.
The long valve-chest has the Ad-
vantage of shortening the inlet ports,
and 80 making a saving in the con-
sumption of compressed air. g.
This drill is further provided with *'
a device for taking up any slackness u
of the feed-screw and feed-nut due ^
to wear. S is the feed-screw and T
the main feed-nut, placed between
the two lugs fand U', forming part
of the same casting as the nylinder.
T* is a second nut, and between T
and T there is a. space V in which is
fitted a spiral spring. T is prevented
from turning by having a flat face
resting against the cylinder cover.
When the feed-screw and the nuts
wear, T* is forced away from T by the
spring and the slackness is remraied.
Z ia & collar upon a stirrup at-
tached to the cradle, and furnishes a
point d'appui for the advance of the
machine when the screw S is turned
by the handle.
(4) The Sergeant drill has the
peculiarity of having two valves, a main valve and an aoxiliary
valve ; the latter is moved backwards and forwards by inclines or
shoulders upon the piston, and, by controlling certain air-passages,
it causes differences of pressure which drive the former.
In Fig. 207 a is the cylinder, b the piston with an annular recess
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194 ORE AND STONE-MINING.
turned in it pmentmg two inclined shonldera ; c ie the Tolve-clieBt
into wbich the compreesed ur enters from one of the aides ; d is
the maiD valve, &nd aa it movee to and fro it alternately places the
port « or y in communication with the exhaust g ; e leads to the
port h and to the front end, and J to the port i and to the rear
end of the cylinder ; j, the auxiliary valve, is a alide-valve made in
the foi-m of a segment of a circle, and having a recess in one of
its flat faoee. It ie slightly longer than it« arc-ebaped seat, so
that one end of it always projects into the cylinder. The pro-
jecting end of the valve is caught by the corresponding shoulder
of the piston as it paasea, and it is thus being constantly knocked
backwuxls and forwards. By means of its rooees this segmental
slide-valve puts the porta k and I alternately into communication
with the port M, which opens into the exhaust. The port k leads
to the front end of the valve-chent, t^e port t to the rear end ;
consequently the two ends are being alternately placed in com-
munication with the exhaust. The compressed air leaking past
the piston-Uke ends of the main valve escapes into the exhaust at
one end of the valve-chest, but exerts a pressure at the other end
where it is confined, and so throws the main valve over, changing
the direction in which the air is being admitted into the cylinder.
The piston makes its stroke, knocks over the auxiliary valve,
which in its turn releases the pressure at one end of the main
valve and causes it to move acroes once more.
The rotation is effected by a rifled bar, n, as usual ; but instead
of there being a ratchet-wheel fixed to this bar with pawls attached
to the cylinder, the rifled bar carries the pawls which work inside
a ratchet-wheel, o, with in-
Fio. ao8. temal teeth and a smooth
exterior (Fig. 208). The
pawls are pressed out by
springs, p (Fig. 207). So
far the action is very like
thatof other drills, save that
the pawls move round inside
the wheel, instead of the
wheel moving round under
the pawls. The special
peculiarity of the Sergeant rotating device is the mobility of
the wheel if the drill jams in a hole. The ratchet-wheel o lies
loose in a recess behind the cylinder, and in ordinary working is
pressed sufiLdently firmly ag^nst the end of the cylinder by steel
cushion springs to make the piston rotate without turning itself ;
but if for some reason the borer jams in the hole and causes a
strain upon the rifled bar, the wheel is capable of turning and so
preventing a breakage.
The feed as usual is by hand; 9 is the handle working the feed-
screw r in the feed-nut a.
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BREAKING GRODND.
'95
{5) In the drills of this cIogs the piston performs a double
function ; it not only acts as a medium for receiving the prM-
Bura of the air, but it also itself uncoTers or closes the passages
by which the air enters or escapes, and so causes a reversal of
the stroke without the intervention of any separate valve.
The AdelauU drill {Fig, 209) comes first alphabetically, although
»V^
it was preceded in time by the Darlington drill, of which it may
be r^srded as a modification. A A represent the annular port,
admitting the air all round the piston, and B^ B^ are porta in the
piston-rod. When the latter are opposite A A, air passes down
through the space C in the piston-rod to the rear end of the
piston, and drives it forward till it uncovent the port B, which
puts this part of the cylinder into communication with the
atmosphere. At the same time £, Ji, have passed beyond the
stuffing-box and part of the exhaust escapes in that direction ;
while this is happening the long shallow annular recess cut in
the piston-rod is brought to A, the air presses on the small
annular apace at the front end of the piston and drives it back.
It will be noticed that this drill uses the air expansively, for
when once if, has gone post A no further supply of power is taken
in. D is the rifled bar, B the ratchet wheel, ff tiie feed-screw,
and G the feed-nut, similar to the corresponding parts of many
other machines.
The construction of the Darluu/toii drill will be understood by
referring to Figs, aio, 211, and 213; a is the cylinder; £ the
piston-rod ; e the borer ; d d are two openings for bringing in
compressed air, either of which may be used according to the
position of the drill ; e is the inlet hose with a stop-cock ; /, drill-
holder ; J, stretcher-bar ; h, piston ;_;', lifled bar for turning piston
aiid drill ; i, ratchet wheel attached to rifled bar ; I, rifled nut
lixed in the piston head ; »i, wood for lessening weight of piston
rod and blocking space ; n, portway for allowing the compressed
air to pass to the I'ear of the piston and give the blow ; o, exhaust
portway. The action of the drill is as follows : — The compressed
air is always acting on the front end of the piston, and when
the rear end communicates with the outer atmosphere, the
piston moves rapidly backwards and uncovers the portway n.
The compressed air rushes through and presses against the rear
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196 ORE AND STONE-MIKIKG.
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BREAKING GROUND. 157
esd of the piston, which haa a greater area than the front
end, the difference being equal to the section of the piston-rod.
The piston is driven rapidly forwards, and the drill strikes its
blow. At the same time it uncovers the eshaust port 0, and
then the constant ' pressure on the annular area on the front
end of the piston produces the return stroke. The number of
blows per minute is from 600 to 800. The rotation of the drill
is effected by the rifled bar. On the forward stroke of the piston,
the bar with its ratchet-wheel is free to turn under a couple of
pawls, and consequently the piston moves straight whilst the bar
and ratchet-wheel turn. When the back stroke is being made.
the i^tchet-wheel is held by the pawls and the piston is forced to
make part of a revolution. As the hole is deepened the cylinder
is advanced forwards by turning the handle p ; this works an
endless screw, 9, pussiog through a nut attached to tbe cylinder ; r
is the cradle carrying the feed-screw and supporting the cylinder.
It is centered on the clamp t. As this clamp can be fixed in
any position on the bar, and as the cradle can be turned on the
clamp, it is evident that holes can be bored in any direction.
In driving a level with a Darlington drill, it is usual to fis the
stretcher-bar horizontally ko ilb to command tbe upper part of
the face ; holes can then be bored with the cradle above the bar
or below it. The bar is then shifted low enough to bore the
bottom holes. It is found that all the necessary holes can be
bored from these two positions of the bar.
The bar, therefore, has to be fixed only twice; the shifting
of the machine for boring holes in various directions is managed
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19S ORE AND STONE-MINING.
by elidiDg or turning the clamp OD the bar and by moriag the
cradle on the clamp.
Fig. 212 shows the Btretcher-bar dzed in a vertical position,,
which is sometimes convenient.
In order to keep the holes clear, a jet of vrater, supplied from
a hone attached to a ^-inch ga>t-ppo leading from a cistern at a
hi^bor l<jve1, is made to play into them during the process of
boring.
For Binking shafts, Mr. Darlington has the drill fixed in a
cylindrical case with a large external thread, which works in a
nut on the clamp. The drill is fed forwards by turning a hand-
wheel attached to the case.
The Marvin Drill * of the Edison General Electric Company is
based upon the principle that a spiral coil of wire assumes magnetic
properties when a current is passed through it, and becomes
capable of exerting a very stroug attraction upon a bar of iron
placed in a suitable position. The actual working parts of the
drill are shown in Fig. 213.
Fio. 213. A and B are two hollow coils
,_ of copper wire (solenoids),
' through which passes the rod
C D. The two ends are made
of bronze, but the central por-
tion, E F, ie of ii-ou. At the
end C there is a socket for
I'eceiving the tool, whilst the
end D is rifled and works in a
mtchet- wheel, and ho effectN
the rotation in the usual iv.ay. A current is led to the drill by a
cable with three wires, shown separately by G, H, and I, and by
means of a very simple revolving armati^re on the liynamo it can
be made to pass, first through one solenoid, and then through the
other, in each case returning by the wii* H. For instance,
we may suppose that the current is passing through the front ■
solenoid ; this becomes magnetic and draws the iron core for-
wardK, andsooauses the t<iol to strike a blow. The current is then
revetted by the revolution of the armature, and flows into the
solenoid B, which in its turn become)^ magnetic and draws the
iron back, for A has lost its magnetic power. The rear end of
the rod C D is made to compress a spring, and so store up
force which is utilised in increasing the strength of the forward
The drill makes 600 strokes a minute, aud is said to be capable
of boring in granite at the rate of 2 inches a minute.
At the present time there are few, if any, electric percussive
drills in regular use in mines, one objection to them being their
■ -'Electric Percussioii Drills," Enij. Miu. Jour., ^■ol. li. (iSgi', p. 6og.
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BREAKING GROUND. 199
great weight compared witb air drills of equal strength ; but it is
Btated thAt they are doing good work at some open limeetotie
quarries at SyracuBe,* N.Y.
IV. Mftohines for Catting Qroovea.— In working a seam
the task of the miner frequently consists in cutting a deep
groove parallel to the bedding with a pick, and so laying it bare
above, below, or in the middle. Wedging or blasting will then
break it away.
The firstr machines for cutting grooves very naturally imitated
the miners' tools, and were simply mechanical picks, but since
thes many other groove cutters have been applied which are based
upon diff^nt prindplee.
They may be clashed as follows : —
I. Hechsulcal pioki, chiaela, and gauges.
3. Travellicg jumpers and rock-dnlla.
3. Circular sane.
4. Eudleas chains with cntteia attached.
5. Wire saw.
6. Bevolving toothed bar.
fi) HeohsQioal Picks, fto-^-Some, like Firth'a machine,
swing a pick like a miner. The Sergeant raachine is a strong rock
drill with a chisel bit, which chips out a groove as a carpenter
might cut out a mortrice. It is mounted on two wheels and can
be handled with ease. Carrett and MarthaWs machine is a power-
ful gouge, worked by hydraulic pressure, which cute out a groove
in coal or soft rocks. These have all been designed more especially
for the collier; but in Franke'e •mecha/nieal chiad (Fig. 214) we
have a tool which is being successfully employed in ore-mining.
It is based upon the principle of string a very large number
of short and lif^ht blows instead of a comparatively small number
of long and heavy ones. It resembles in some respects Crossley'e
mechanical caulking tool and McCoy's chisel.
The following description is derived from accounts given by
Pilar and Schrader,+ and from personal observations at Mansfeld ;
a is the outer shell of the machine, b the inner or real cylinder, e the
piston with the annular slide-valve r, d the tool-holder carrying
the chisel in a deep socket ; the air is brought in to a by the pipe
t, and finds its way into b through four broad, low passages, mi. m,
and ^xteen small ports, similar to n n, ^'g- inch in diameter. The
front part of the outer shell, a', serves as cylinder cover and as
guide for the piston rod, and lastly to contain the tool-holder d,
surrounded by two spiral springs in the space between the shoulder
p, and the cover «. The opening, o, allows the air to escape in
front of the piston-rod, and so makes the stroke easier; I is the
exhaust port, and q a hole for lubricating ; r is the ring valve,
• Eng, JUin. Jour., voL Iv. (1893), p. 491.
+ Jobann Pilar, " SohrammeUsel, Systeni Fratike, im Uaosfeldiachea,"
Oe»t. Ztitichr. B.- V. H.- IF., vol. il. (1892), p. 78. Sohrader, op. tit. p. 171.
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»oo OEE AND STONE-MIKING.
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BREAKING GROUND. 201
sliding upon the piutoD, aad aa soon as it ie drawn past the port
», it is driven either forwards or backwards by the air preseure.
In the podtktn ehowa Id the figure, representing the end of
the return stroke, the valve r has been driven ba(£, and the air
is enabled to pass from m. into g, and so to the back of the piston.
The air in the space in front of the piston finds an exit along the
three passages h, of which only one can be shown in the section,
Mid entering the annular slide-valve, is brought by one of the
three radial passages, t, into the hollow central ptut j^ of the
piston and piston-rod, and eventually to the exhaust I. As soon
na the piston, in its forward stroke, draws the valve r past the
port n, it is thrown over by the air pressure ; g, through r,
now communicates with t, and the air pamea from the rear end of
the piston to the exhaust ; at the same time the three passages
h are connected with the admission inlets of compressed air, and
th^ piston makes its return stroke. The piston is thus driven
badiwards and forwards, striking a rapid succession of blows,
estimated at several thousand per minute, upon the back end of
the tool-holder d, and as fast as the latter is knocked forwards it is
drawn back by the action of the springs. The tool-holder ia in no
way connected with the piston, and is quite free to turn round.
The length of tlie stroke of the chisel ia only o'o6 to o'o8 inch
{i'5 to 2 mm.) As the annular slide-valve closes the ports n n in
passing, the air acts by expansion during the latter part of the
stroke. The air-pressure employed at Mansfeld is 60 lbs. per
«quare inch (4 atm.)
The chisel is made of ^inch round steel with an edge | inch
wide; it is inserted in the strong socket of the tool-holder, and
the miner simply holds the cylinder so that the chisel presses
against the shale which he wishee to cut away (Fig. 205). It is
said that a man can undercut or '* hole " an area of 5 square feet
(o'5 sq. m.) per hour. Each hewer has to make a "holing"
about 10 feet (3 m.) long, and he carries it in to a depth of 30
inches to 2 feet from the face. The groove or " holing " is about
5^ inches (14 cm.) high at the face, and becomes lower and lower
as it goes in.
The men do not appear to suffer in any way from the vibrations
of the machine, which weighs only 10 lbs. (4-5 kil.) including the
chisel.
(2) Travelling Book Drills and Jumpers. —A groove may
be made by boring a succession of liolee immediately touching
-each other, or separated by small partitions which are broken
down afterwards by a flat bit (frroocA). Moat of the rock drill
-companies supply special quarry-bars or frames, upon which an
ordinary baring machine can be mounted and made to travel,
and thus cut a gi-oove along any required line.
With the IngtraoU bar-eAamtellei- ' u cutter is sometimes used
* £11^. ilia. Jour., vol. ilix. (1890), p. 62.
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loz ORE AJUD aTONK-MINING.
made of three chisels placed side by side, with their edgett arranged
like the three strokes of the letter S, in tJie place of an ordinaiy
borer. An the carrying frame can be inclined, the groove can
be cut at an angle.
The WardieeU • eUms channeliing and quarr^ng tnackine may
be regarded as a mechanical jumper, cutting a vertic^ groove.
It IB a portable 6 h.-p. engine with boiler, moving upon rails,
which is made to lift a set of boring chisels or cutters consisting
of five bars of square steel, clamped together in a line. The edges
of the centre and outride cbisels are transverse, whilst the other
two are diagonal, and they are arranged in step fashion. Three
cutters ooly act at a time, viz. the centre cutter, and either the
two in front or behind it, according as the machine is being
moved forwards or backwards. " The machine consumes 400 lb.
of coal a day, and requires the services of three men. It will cut
from 75 to 150 square feet of channel in marble, and 150 to 400
square feet of limestone and sandstone in a day, which is
equivalent to the work of 50 men."
The Cleveland Stone Company, Ohio, employs no less than
tliirty-nine of these machines in quarrying sandstone, with the
iQodi£cation of having only three cutters instead of five.
The channelling machines of the Ingersoll and Sullivan Com-
panies running upon rails, either with or without a boiler, will
cut vertical or inclined grooves.
(3) Circular SaWB. — In alphabetical order the following may
be named ' Crump and Brereton, Gillott and Copley, Walker,
Winstanley,
Crump and Brereton'a + maehine is used for quarrying stone in
the United States. It will cut long vertical grooves 30 inches
deep and about | inch wide.
It consists of a frame on wheels, moving upon rails, which
carries a small vertical boiler, steam-engine, circular saw about
5 feet in diameter, and the gearing necessary for driving it and
causing the whole carriage to advance as the cut is made. The
saw is a thin circular steel blade, about | inch thick with slots all
round the edge into which the teeth ai« inserted. They are
arranged so that they divide the narrow cut of | inch into 3 parts,
each tooth taking \ inch. The teeth ai-e sharpened by grinding.
Tlie saw is driven from the periphery by a toothed wheel on each
side, the teeth of which gear into two cii*cular sets of faolee cut
near the circumference of the saw. It is said that while making
a cut 30 inches deep in slate, it will progress at the rate of
4 inches a minute.
The Gillolt a7>d CopUyX machine {Fig. 215) has been specially
■ Kiig. ilii'. Jour., vol. xlvii. (1889), p. 500.
1 Kngiiieerimj. vol. ili. (1886), pp. 154, ^^2.
X G. B. Walker, "Coal-getting by Machinery," ft-oc./W, /n»(, Jf/ii.i%.,.
vol. i, (1S90), p. 138.
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BREAKING GROUND. 203
designed for cutting a more or less konzontal groove, under or in
a seam of coal, but it can tilso be applied to seams of other com-
paratively soft mineralfi. It is a cast-steel or malleable iron wheel
4 feet in diameter, armed with removable teeth, which are alter-
nately double and single. The groove which is cut is rather more
than 3 inches wide, and is big enough to allow the bracket sup-
porting the SAW to enter it. Consequently, a cut can be made
nearly as deep as the diameter of the saw.
Just inside the circumference there is a circular rack into
which gears a bevel pinion driven by two compressed air engines
with cylinders 9 inches in diameter and having a 9-inch Gtiroke.
The saw makes about 30 revolutions a minute. The two engines
are upon the carriage which supports the saw. The carriage runs
upon rails set at a gauge of i foot 7 j inches, and it draws itself
Fig. 215.
along by a wire rope, which has one end fixed at some convenient
point of the working face, and the other coiled upon a drum
attached to the carriage. The drum is made to revolve by a
pawl and ratchet-wheel worked by the engines, and there are
means of regulating the number of teeth taken by the pawl,
and in this way the advance of the machine.
Two men are lequired for working the machine ; the man
in front lays down the rails and sleepers, which are taken
up and passed to him by the man in the i-eai- as soon as the
machine has gone over them. The whole machine is only i foot
9 inches above the rails ; its width, exclusive of the saw, is 3 feet
3 inches, and total length 9 feet ; it weighs altogether 24
cwt. The makers state that it will undercut to a depth of
39 inches in hard coal or shale at the average rate of 12 yards
per hour, with an air pre^sut'e of about 30 lbs. per square inch.
The saw cuts from back to front, tind therefore clears out the
chippings that it makes.
The Rigg and Meiklejohii machine, which is in operation in
Scotland, is a circular saw of somewhat similar construction.
The cutting of a preliminary groove in some of the Cheshire
salt mines has long been done by Walker's circular «nip (Fig. 216).
An improved form of the Winatanlty miv is doing good work at
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204 ORE AND STONE-MINING.
tbe Blanzj' collieries. It is a circular saw 5 feet (1-50 m.) in
diameter, with 28 removable cutters, all of one shape, upon its
circumference. The cutters ai-e arranged in fours, so that four of
them cover the whole width of the holing, which is 3 inches
(7-6 cm.) high. Two small compressed air engines, inside the
waggon which carries the saw, drivp a horizontal pinion, which
gears into the spaces between the cutters ; in fact, the saw is a cog
wheel with a cutter inserted into each tooth. The depth of the
holing is 4 feet. The total weight of the machine is 35 cwt.
(1800 kil.)
(4) SndlesB ohain with nutters attached.— ~£atnf««uM/ii}(«,*
which 18 used both for coal and ironstone, is of this type. A
carriage moving on rails supports two cylindera worked by com-
pressed air, and these set in motion an endless chain with cuttera,
which revolves round two pulleys, one at each end of a jib or arm.
The jib caii be made to extend under the seam for a distance
varying from 2 feet 9 inches to 5 feet, and the groove which is
cut is only 3^ inches high.
It is stated that a macliine will make an undercut 2 feet 9
inches deep by 100 yAtds long in 8 or 10 hours.
(5) Wire Saw. — The most novel method of cutting atone is
one which has been used at marble quarries in Belgium and else-
where, and is called by the inventor the Helieoidal Saw System,
It consists in sawing grooves by an endless cord, composed of
three Hteel wires twisted together, which travels ou the rock, and
is supplied with sand and water. The sand is drawn along by
the spaces between the wires, and will cut even very bard stone.
At present only vei-tical grooves have been cut ; the first process
consists in sinking two pits for receiving the pulleys which guide
the cord in making its cut, and which have to be lowered as the
cut is deepened. The pits are bored 2 feet 4 inches {700 mm.) in
diameter by cylinders of sheet-iron, with the lower and cutting
edge made of sheet-steel. The cyUn<ler is made to rotate at the
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BREAKING GRODND.
205
rate of 100 to 180 revolntiom; a minute by a vertical axis set in
motion by a horizontal pulley at the top, driven by a wire rope,
whilst sand and water are fed in to the cutting edge, Ab the
annular groove is cut deeper and deeper, the cylinder is gradually
lowered by a little winch and two wire ropes. The cylinders now
in use are constructed so as to cut to a depth of 10 feet 9 inches
(3-30 m.). When this cut has been made, a core remains, which
can easily be broken off at the bottom and lifted out. In the
case of marble the core can be utilised and sold as a column. If
there is a demand for smaller columns, boring cylinders of less
diameter are used, and two or four botes are bored side by side.
After the removal of the columns the thin intervening partitions
of rock are broken down, and space enough is afforded for the in-
troduction of a pulley and a frame.
Two of these pulley-pits are prepared at the tvk-o extremities of
the line along which it is desired to make a saw-cut, which may-
be 50 feet or morein length, if required, and the cairierH are then
inserted. The carrier, made of channel iron, supports two
pulleys, each 2 feet in diameter ; one is fixed at the top, whilst
the second is so arranged that it cf(n be lowered by a large screw.
The cord for sawing in the quarry is about J inch (6 mm.) in
diameter, made up of three wires of mild steel, twisted together ao
Vic. 217,
as to form a strand. It is driven at the ratt: of 13 i'eet (4 m.)per
minute, and will deepen the cut in marble at the rate of 3 to 4
inches or more per hour. The friction of the spiral wires on the
pulleys and rock causes the cord to revolve a little as it is carried
forwards, and all parts of it are thus equally worn. When it is
BO much worn that it no longer presents spiral spaces which will
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2o6 ORB AND STONE-MINING.
hold aamd, it has to be changed. If it breaks while in use, it can
very easily be epliced.
Fig. 2 1 7 represents the arrangement adopted at the Traigneaux*
Qaarry, near Philippeville, Belgium. A B G D E F ia the wire
cord travelling in the direction shown by the airows ; H and G
are the two pits which have been bored to hold the pulley-frames.
"When the cutting process began, the wire cord would have been
sunning along the line I J ; the groove is gradually deepened
untU at last it reaches the line K L.
When suitable vertical cuts have been made, the block is
severed horizontally by means of wedges.
(6) Revolving Bar with Cutters.— Under this head may bo
classed the Bower, Lechner, and Legg machines, all of which have
been designed for holing coal.
Bower's machine consists of a bur 3^ feet long, armed with
steel teeth, which is made to revolve at the rate of 600 to $00
revolutions a minute by an electric motor. The bar rapidly cuts
away a groove as the motor is made to travel along the rails ; tha
groove is 5 inches high in front, and 3 at the back.f
In the Leehner and LeggX machines the cutting bar lies parallel
to the line of the face, and not at right angles to it, as in Bower's
coal-cutter.
V. Hsohines for Excavating Complete Tunnels — Hither-
to machines of this kind have been little used. Three may be
mentioned — viz., the Beaumont, Brunton, and Stanley tunnellers.
The Beavmont machine has received a good detU of notice,
owing to its having been employed in the Channel Tunnel. It
consists of a very heavy horizontal iron shaft, which is made to
revolve by compressed air engines. The shaft carries a cross-head
armed with teeth, which cut away the whole face by a series of
concentric grooves. The chips are made to fall on to au endless
chain with buckets, and are thus conveyed to a waggon behind
the machine, so that no interruption of the work takes place for
loading. The machine travels forwai'd in a cradle which fits the
battom of the circular tunnel, and when the limit of advance is
reached, the machine is lifted up by screw-jacks, and the cradle
\» once more brought under it, so that a new cut can be begun.
Like the Beaumont machine, Bruntmi'a tim7idler% excavates a
circular drift by chipping away the whole face, but in this case
the work is done by steel-cutting discs about 10 to zo inches in
diameter, and from \ inch to i inch thick. As yet it has been
little used.
• Copied from a pamphlet published by the SociMaaonipiKintrTnatiotiide
duMhdi^oidal, BmsselE, iSSS.
+ G. B. Walker, " Coal-gettiug by Machinerj," iVoc. /eJ.JiM(.i/iN.£'i(j.,
-vol. i. p. 129.
J Eng. Min. Jour., vol. xlvi. (Jane 1888), p. 399.
i Jimr. Soe. ArU, vol. xai, (1873-74), p. 404.
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BREAKING GROUND. 207
Slanlej^s tunndter (Fig. 218), oa the other hand, is a compara-
tively new machine already doing good work in driving headings
in coal. It consists in the main of a strong central shaft, which
carries a croBs-head with two projecting arms. At the end of each
arm are three steel teeth or cutters. The central shaft is made to
revolve by a pair of small vertical compressed air-engines, and the
teeth cut away an annular groove 3 to 4^ inches wide. The chips
are btvught out by scrapers attached to the arms which carry the
teeth. The advance of the cutters is caused by the forward
movement of the main central shaft ; this is screwed oub^ide, and
works in a nut attached to the frame. The rate of advance
is therefore determined by the pitch of this screw and the speed
with which it is made to turn round.
After boring the annular groove to the depth of a foot or so,
large lumps of the central core break off, and the machine is
stopped to get them out. Work is then resumed till the arms
have penetrated to their full length. The machioe is stopped,
the remaining part of the core is wedged out and cleared away,
and now the frame is run forward and fixed for another cut.
The rate of progress when working in coal is about 1 yard per
hour, and during a trial of 24 hours the machine cut a tunnel
64 feet 6 inches in length. The diameter of the headings or
tunnels is 5 feet. A machine for worlc'ing in harder rock with a
slower cut is being tried.
Stenley has also made a modification of his tunneller in which
the whole of the face is cut into Uttle pieces ; the chips are earned
off by an Archimedean screw and delivered into a waggon at the
hack.
uoDES OF usiira holes fob bbeaeinq
QBODli'D. — After holes have been bored, either by hand or by
machinery, a force of some kind has to be applied inside them in
order to produce a rending action. The commonest method is to
employ an explosive, but the treatment of the subject would not
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ao8 OKE AND STONE-MIKING.
be complete witboat a brief mention of some other processefi.
Holes may receive : — '
I. WedgcB.
3. Water.
3. Wociden plugs.
4. OompresEed air oarirulf^ef .
5. Hjdnnltc cartridges.
6. Lltoe cartridges.
7. Bzplostves.
I. We^ea.— W hen a bole has been bored, a compound wedge
can be inserted which can do the work of splitting with far
greater ease than a single wedge driven into a mere crock in the
rock. The combination of three wedges is known as the jiug and
ftathers, ft flat wedge, the plug, being inserted between the
feathers, which have the outer face curved. The feathers are
placed in the hole and the plug is driven down between them with
a hammer or sledge.
Varieties of this simple apparatus, in which the wedge or the
feathers are moved by hydraulic pressure or by a screw worked
t^ hand, have been used for getting down coal. Fig. 219 is the
Elliott multiple wedge of the Hardy Patent Pick Company.
2. Water. — In cold climates the expansion of water in freezing
can be utilised for rending rocks in open quarries. A row of holes
is bored in the line along which it is wished to spUt off a block of
stone, the holee are filled with water and well stopped with wooden
plugs ; when the water is converted into ice, the block splits off.
3. Wooden FlngB.— Drj- oaken plugs are driven into holes and
then watered. The wood expands and causes a fracture.
4. Compressed Air.— Air compressed to about 400 lb. per
square inch has been employed experimentally in the place of gun-
powder for breaking down coal.
5. HydTBUlio Cartridges.— Le vet proposes to use a flat
metallic tube placed in a borehole, whidi is rammed up tightly.
The fiat metaUic cartridge is then connected with an hydranlic
press, and as eoon as this is worked the cartridge expands, and
the coal is broken off.
6. Iiime Oarteidges. — This plan is mentioned with the two
last, not because it is employed in mines at the present time, but
simply to complete the series of methods of applying a rending
force in boreholes.
A small iron |dpe is first placed in the borehole, which is
li inches in diameter, and then a cartridge of compressed lime
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BREAKING GROUND. ao^
with a groove to fit the pipe is inserted. The hole is now tamped
up, and water pumped into the pipe, satumtiag the charge.
Ch«at heat is evolved, some of the water is converted into
steam, the lime ezpanda, and large blocks of ooal are broken off.
7. Bxploaives. — Thirty years ago gunpowder was practically
the only substance used for blasting at mines ; but nowadays the
number of exploaivea is great, and an exact classification is
neceeaaiy before they can be conveniently studied.
With the permissiou of Colonel CundilJ, R.A., I borrow the
classification, as well as certain detaib, from his Dictionary of
Ezploeives.*
I. Gunpowder ordinaiilj ac-called.
3. Nitiate nuitnres other than gnnpowder.
3. Chloiata mixtnrea.
4. NitTo-oompoands oontainlng nitrn-gljaermB ; this inclndes the great
d;yiuumte olasa.
5. Nltro-oompouuds, not containing uitro -glycerine (gnn-cotton, Sui.)
6. Bxploslves in which plorlo Boid, or a picrate, is a main oonatitoent.
7. Bxploaives of the Bprengel type.
8. MiBcellaneous ecploslves.
(1) GtULpowder. — Though gunpowder has lost much of its
former importance, owing to the greater strength of many of its
younger rivals, it is still largely employed for several reasons, viz.,
its relative cheapness ; its slower action, which renders it more
suitable for blasting in certain soft rocks and for producing rents
without any violent smashing; and lastly, its freedom from
certain dangers which cling to some of the nitro-compounds.
The formula commonly given for gunpowder is : 75 parts of
saltpetre, 15 of carbon, and 10 of Bulphmr; but the powder
used for blasting in mines usually oontuns less saltpetre than
that which is employed for nmrting or military purpoeee.
The following is an an^ysis of mining powder by Captain
Nobel and Sir F. Abel :—
Pntcnt,
Saltpetre 61-66
Fotauinm anlpbate 0-12
Potasdnm chloride 0-14
Solphnr iS'o6
Carbon i7'93
Hydrogen 0-66
O^gBD 2-13
Arfi o-W
Water i-6i
The products of the explosion of gunpowder, according to the
Kune autbon,t are by w^ht :
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OKE AND STONE-MININO.
Sn^^^!
PO-dM.
Total solid prodnotB ....
Total gaseooB prod acts ....
Water
S7-74
4109
I- 17
4704
,oo.«
loo-oo
The solid residue of the miniiig powder consiBted mainly of
Xttassium carbonate, potaseiam mooosolphide, and sulphur.
The percentage oompoeition, by voluine, of the gas produced
CatOMkBMzm'M
Po-diF.
Carbonic aahjdride ....
Carbonic oiido
Nitrogen
Solpboretted hydrogen
Uarahgaa
Hydrt^en
50-"
7-52
3446
I'OS
3a- 15
33- 7S
19-03
7- 10
3-73
S-a4
100^00
.0,00
The volume (calculated for a temperature of o* C. and barometer
760 mm. of mercury) of permanent gasee generated by the ez-
plodon of I gramme of d^ powder is :
Mining powder ia usually coarae-grained and highly-glazed, but
the workmen who adhere to the old plan of finng with straws
require a little fine-grained powder for filling them. In quarry-
ing and mining elate, a fine-grained gunpowder of very good
auality has been fonnd by experience to answer best for rending
iie rock evenly without smashing it.
Gunpowder is used either loose, or in cartridges made by the
men on the spot, or in cartridges supplied to them. Gunpowder
compressed into cylinders of diameters suitable for bore-holes, and
provided with a central hole for the infiertiom of the fuse, has
Utely been brought forward with some success; but it has the
great disadvantage, shared with all bard cartridges, of not fitting
uie bore-hole so closely as a pulverulent or plastic explosive.
(3) mtrate Mixtares other than Q-unpowder. — As niteate
of soda is veiy much cheaper than nitrate of potash, inventors have
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BREAKING GROUND. m
natoT&lly tried it aa a Enbetitute for the most expensive in-
gredient of gunpowder. The drawback of such ezploaivee is that
they get damp, owing to the deliquescence of the nitrate of soda ;
and some of the so-odled waterproof cases have been insufficient
in the humid climate of Great Britain to keep out the moisture
(3) Chlorate Mixtures. — Chlorate of potash is an unstable
salt, very sensitive to friction and percussion, and the explosives
made from it are so dangerous that only one, aaphaline, has been
licensed in Great Britain. It was ho light and bulky that it
never came into practical use.
Rack-a^rock is chlorate of potash soaked with " dead oil," a
dark heavy oil consisting chiefly of hydro-carbouB, and derived
from coal tar, or with a mixture of equal volumes of dead-oU and
bisulphide of carbon, or with dinitro-benzole. The cartridges of
compressed chlorate of potash are dipped ia the liquid when re-
quii«d for Ose ; the two ingredients, when separate, are not
exploeiTe.
More than 100 tons of this explosive were used in the great
blast for removing the Hell Gate rocks in New York Harbour,
beades which large quantities had been consumed in making the
onderground galleries. The variety employed at Hell Gate con-
sisted of 79 parts of finely-ground i^or&teof potash, and zi parts
of dinitro-brazole.
(4) Nitro-oompoonda oontalning Nitxo-glyoerine. — Miners
are deriving immense benefits from explosives of this class which
includes dynamite and its congeners.
Nitro- glycerine or glyceryl nitrate is a light yellow oUy liquid
with a specific gravity of i-6, which freezes at abont 40° F.
'{4* C), and explodes when heated to 360° F. (180° C), or sub-
jected to a sho^
Its chemical composition is expressed by the formala
0,H,{NO,)^ and it is prepared by the action of nitric acid upon
glycerine. It is exxramely sensitive to shocks, and under the
action of a fulminating cap it explodes with great violence. It is
less sensitive to blows ana detonation when frozen than in the
liquid state.
The results of its deoomposition when perfectly exploded may
be represented by the following equation : —
aC^CNOJ, = 6C0, + sH,0 + H, + O.
MM. Sarrau & VieiUe* have communicated to the Academy
-of Sciences the results of their researches concerning the decom-
position of certain explosives, among which ia nitro-glyoerine. The
■ "BechGtchssexp^rimetitalesBuiladecompoBitlondequelqiies ezploslfe
en VSB cloH ; compOEition des ^i lorm^ : " Coniptta Henaui, 1880, pp. 105B
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2-12 ORE AND STONE-MINING.
foUowimg table shows, in litres, the volume (at o° 0. and 760 mm.
of mercuiy) of each of the gases per kilogramme of the subetance
exploded in a closed veesel.
CO ' CO,
H 1 N
0
c;b.
H^ ToU
Para gsn-oottoD .
234 234
166
107
_
_
— 741
Gnn-oottoii and nitiala
o( potash (50 percent.
1
Gun-eotton (40 per coat.)
and nitrate of am-
monia (60 per cent.) .
- 1 184
— 4<»
Nltro-g1;oenne .
— 295
147
as —
Ordinar? blasting pow-
1
64 15°
4
OS
— 4
"7 304
If, howerer, the ezploeive is decomposed, at a pressure approach-
ing that of the atmosphere, by biinung or imperfect detonatioQ,
the Tolumee (again at 0° C. and 760 mm. of mercmy) are very
different, as shown below : —
KlBdofBiplortTfc
N<^
CO
CO.
H
N
C,B.
Tot»l
Pnre pin-ootton
Cron-oottoa and nitrate of
potaih (5operoent, of each)
Qnn-ootton (40 per cent.) and
uitiata of ammonia (60 per
cent.)
Nltro-glyoerine
'39
'■
118
58
161
S7
11
45
3
7
33
7
6
7
S6S
196
414
4S2
When these explosives are decomposed in this way, they liberate
nitric oxide and carbonic oxide, and the analyses of MM. Sarrau
Je Tieille confirm the practical experience of miners, who complain
greatly of noxious fumes, when, owing perhaps to a bad detonator,
a charge of dynamite or tonite fails to explode properly.
Nitro-glycerine was at first used alone, and was fired by &
small cartridge of gunpowder inserted into a strong paper case
containing the hquid ; this method soon gave way to ^e fulminat-
ing cap. Numerous accidents happened from the extreme sensi-
tivenesa of the blasting oil to percussion, and these led to its being
given up in most countries. Xobel, who had introduced nitro-
glycerine, then invented a method of using the explosive with
comparative safety, by causing it to be absorbed by some parous
inezpiosive substance. This was the original dynamite, but now
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BREAKING GROTIND. 213
■vBiions mixtures of nitro-glycerme and other Bubettmoes are made,
and we may place them all in the great dynamite class.
The dynamites may ooDveniently be arranged in two groape :
DTii&mites with an inert baie acting merely as an abaoTbent for the
. d mCro-Kljcerine. Biample: Ordinarr dTiiamJte.
3. DjnaBUtes with on active, that U to say, an ezploiive cr oombiutible
liquid mCro-Kljcerine. Biample: Ordinarr dTiiamite.
3. DjnaBUtes with an active, that is to saj, an ezploiive c
base. This ezploaiTe or combnitible base may be (diarooal, ^fonpowdi
•other nitrate or chlorate miztnrea, Ktut-cotton or other aotive ooroponnds.
Szamplesi — Blasting gelatine, Gelatine dynamite, Qelignite, Hercules
powder, Litbofractenr.
Dynamite was made originally by mixing 75 parte by weight of
thoroughly purified ultro-glycerine with 35 parts by wei^t of
infusorial mrth, known as KinaeiguhT, sufiEciently absorbent in
quality when mixed in the above proportions to prevent exudation
m the blasting oil.
The Biitish Uoense for making dynamite now allows the
Addition of a little carbonate of ammonium and the eubstltution of
carbonate of sodivmi, sulphate of barium, mica, talc, nitre, for a
portion of the Kieselguhr.
At ordinary temperatures dynamite is a plastic mass, gene-
rally somewhat reddish in colour, owing to a little ferruginous
matter in the infusorial earth. It freezes at about 40° P. (4° C),
and when once frozen remains hard at higher temperatures than
40° F.
In the frozen state it is less sensitive to blows and detonation
than when plastic, but it is more susceptible to explosion when
set on fire. At some seasons in certain climates it has to be
thawed before b«ng used. The natural warmth of some mines is
sufficient to soften it in the short interval between the time it is
taken below ground and the time it is required for use ; but it is
often necessary to resort to artificial thawing, A special pan is
Bupi^ied by the makers for this purpose. It consists of an outer
can filled with hot water, which endoees a receptecle for the
explosive. The out«r can is surrounded by a b^ of painted
canvas filled with a bad conductor of heat, so that the water
retains ita warmth for a long time. The warming-pan cannot be
put on to a fire without the outer covering being burnt ; if proper
cans are supplied, the men are less likely to try the dangerous
experiments of warming dynamite in an old meat-tin over a candle,
or upon a shovel at the smith's forge, methods of thawing that
are not unknown.
The trouble of thawing, and the possibility of the operation
being perfwmed in a lungerous manner by the miners, are
dedaea disadvantages to dynamite ; and these are not the only
once. Its behaviour with water is a source of danger. If left in
contact with water, as happens sometimes when a hole misses fire, it
its way into cracks is liable to explode with violence from the mere
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214 ORE AND STONE-MINING.
coqcusbIod, when the rock is struck with the pick, borer, or sledge..
A fourth dr&wback lies in the fact that the whole of the chiu^
does not always go off ; portions may remain intact and then explode
unexpectedly from a blow, when work is resumed after blasting.
On the other hand, the plasticity of dynamite and some other
nitro-glyceriue ezploaiTes is a decided benefit, becanse the charge
can be pressed down so as to fit a hole which is not perfectly
oylindrioil, or a cartridge can be squeezed flat and inserted into a
crack without boring any hole at all. Of course, the main adran-
tsge of dynamite and its congeners over gunpowder is their
enonnaus strength.
Atlas Powder. — This is a lignine dynamite, consisting of wood-
pulp or cawdust, nitrate of sodium and nitro-glycerine. It is
manufactured in the United States.
Btatling Gelatine. — This powerful and favourite explosive is-
made by "living nitro-cotton (nitro-cellulose carefully wsahed and
purified) with nitro-glycerine heated to about loo* F (38° C.)-
until enough nitro-cotton has been dissolved to convert; the nitro-
glycerine into a jelly-like mass. The blasting gelatine in ordinary
use contains 93 to 95 per cent, of nilro-glycerine, the remainder
being nitro-cotton. In the plastic state it is less sensitive to a
shock or blow than dynamite, but when frozen the reverse is the
case. One great advantage which it possesses over ordinary
dynamite is that it is practically unaffected by water. That it
must be stronger than ordinary dynamite is evident at first sight,
because an active exploeive is substituted for a wholly inert snb-
stence. But there is the additional reason that the two ezplosivee
mutually assist each other. The ezploeion of nitro-glycerine, as
we have seen, liberates free oxygen ; that of nitro-ootton liberates
carbonic oxide. In other words, the former explosive has more
c^gen thsjk is necessary for complete combustion, the latter less.
The excess of oxygen of the nitro-glycerine makes up for the
want of it in the nitro-cotton.
G^atiTte dynevmiU is a mixture of So per cent, of blasting gela-
tine with nitrate of potassium and wood meal.
Geligmle is a similar mixture containing only 60 per cent, of
blasting gelatine.
Giant powder is a term used in America for dynamite. The
Giant powder used in Califomia consists of nitro-glycerine, nitrate
of sodium and wood-pulp or sawdust. Like Atlas powder it is
therefore a lignine dynamite. Several varieties are made con-
taining from 30 to 80 per cent, of nitro-glycerine.
In SavtUei potoder, also an American explosive, the nitro
glycerine is mixed with wood-pulp, carbonate of magnesium, and
nitrate of sodium, or with carbonate of magnesium, chlorate of
potassium, nitrate of potassium and white sugar.
lAthofraetntr is no longer seen in England, though r^pilarly
used in the Australian Colonies,
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BREiKING GROUND. 215
It may be looked apon as ordinal; djnamite mixed with a
erode sort of gunpowder.
One analysis g&ve—
Nitm-gljoerine J3
Kienelgahr 30
Powd^ed ooal 12
Nitnte of Bo6a. 4
Sulphur 3
Otii^ rarieties of tlie explosive contain each ingredients as
cli&rcoal, bran, sawdust, nitrate of barium, bicarbcmate of sodiam.
(5) Nltro-oomponnds not oontainiiiB Nltro-glyoerine. —
The ezplosires of this class now in practical use are made from
the nitro«onipoandB : — Kitro-cellolose, Nitro-benzole, or Nitro-
naphthalene.
yitro-oeUuloae or ffurtreotton is prepared by the action of a
mixture of nitric and sulphuric acids upon cotton. A mixture of
certain definite proportions and strength is used in order to secure
the special product reqtiired as a blasting agent. It lacks the
plasticity of dynamite and blasting gelatine, but it can claim the
advantage of never requiring to be thawed. It is made up intb
cylindriral cartridges to suit bore-holes of various diameters, with
a central hole for the insertion of the fulminating cap or
detonator. Per ee, gun-cotton is not largely used in mining.
When gun-cotton explodes properly its decompositioa may be
represented by the following equation : —
2(C,H,0„3NO,) = 9CO + 3CO, + 7H,0 + N,
One of the products of the ex]doeion is the poisonous carbonic
oxide. This disadvantage can he counteracted by the addition of
a nitrate, and tonite is an explosive produced in this manner. It
is a mixture of gun-cotton and nitrate of barium, sold in cylin-
drical cartridges coated with paraffin to keep out the moisture.
By some miners it is preferred to dynamite for reasons of safety.
It doea not freeze, and there is no danger of exudation of ao ex-
plosive oil, when a charge which has missed fire has to be left in
a wet hole.
Ammonite is a mixture of nitrate of ammonium with mono-
nitro-naphthalene. B^lite is a mixture of nitrate of ammonium
with di- or tri-nitro- benzole. Koburite is essentially a mixture
of nitrate of ammonium with chlorinated di-nitro-bensole. It is
a yellowish-brown powder, and is sold in cartridges. Sometimes
there is also some chloro-niti'o- naphthalene as an ingredient.
It is largely used in coal mining. Seeu/rite is an exploeiTe of
similar composition.
(6) Florio Acid and Fioiatea. — No explosives of this claas
are in use in mines or quarries.
(7) Bxploaivea of the Bprengel Type. — Br. Sprengel pre-
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3l6
ORE iND STONE-MINING.
pares explosivee on the spot immediately before use, from
aubBtaucee whicK by tbemselves are not explosive. He mixes a
combustible body with a highly oxidised body In sach proportions
that the supply of oxygen ^hall produce complete combustion, and
he fires the mixture with a detonating cap.
Thus, for instance, uitro-benzole compounds are mixed with
nitrates of ammonium, potassium, or sodium. These could be
placed in Claas 5. Rack-a--rock, mentioned in Class 3, is an
explosive of the Sprengel type.
Dr. Spiengel's method cannot be employed in this country,
because it is not legal to manufacture explosives, even by mere
admixture of the ingredients, except in duly licensed factories.
(8) HiBcelioneoufl ExplosiveB. — Fulminate of mercury, used
in niaking detonators, is the only explosive of this class which
requires any mention. Detonators are small copper cylinders,
closed at one end, containing a small quantity of fulminate of
mercury. They are made of various sizes to suit different
explosives.
Strength. — The strength of explosives may be compared
by firing them in holes bored in leaden cylinders, and then
measuring the size of the cavity produced in each case. Fig.
320 shows a hole 6 inches deep bored in a strong block of
lead. Thefiringof 20 grammes (iij drachms) of gunpowder in
such a hole enlarged it but slightly (Fig. aai), whilst the dila-
tation caused in similar holes by firing like charges of dynamite
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BREAKING GROUIO). 217
(Rg. 332), gelignite (Fig. 223), gelatine dyDamite (Fig. 334), and
blasting gelatine (Fig. 225) illustrates the enormonalj' greater
power of these nitro-glyoerine explosives.
Charging and Firing. — The commoneBt method of firing a
charge is by means of the safety fose, a cord yV ^ I ^^ ^
diameter, containing a core of gunpowder introduced during the
process of manufacture. TJpwards of forty or fifty varietdee are
made to suit the requirements of the miner and the quarryman.
The oord is somewlw,t guarded against damp by tar, and, if more
proteotdim is needed, the covering is increased in thickness, and
a layer c^ varnish is interposed. For wet ground the outer
part of the fuse is formed by one or two s^oral coils of tape
or by gutta-percha. For blasting under water, the coat of gutta^
ptttiha is often strengthened against injury by tape, or is doubled
or trebled. If still more care is neoeesaiy in order to secure an
absolutely impervious envelope, the fuse is made of lead tube, either
bore or protected in various ways. Special fuses are supphed for
export to warm countries. Fuse is usually sold in coils 24 feet in
length, but it can be obtained in longer coils tixe special purposes.
One or several white or coloured threads run down the centre
of the core of powder, and serve as trade-marks by which the
goods of different manufacturers can be recognised. They are
sometimes impregnated with nitrate of potassium, with the view
of carrying the fire along in case there should accident^y be a
slight interruption in the continuity of the core. Safety-fuse
bums at the rate of about two or three feet per minute, so it is
easy for the miner to secure ample time for retreat by taking a
Buffident length. Sometimes a fuse hangs fire, and many are the
accidente that have beeu caused by returning too speedily to a
hole on the supposition that the fuse had failed altogether.
" Hang-firea" may be due to damp, imperfection in manufacture,
or injuries before or after the fuse was put in the hole. Colonel
Majendie has shown that oil exerdsee a very retarding effect up(Hi
the rate of burning of safety-fuse.
In blasting with gunpowder in the ordinary way, the charge is
put in either loose or enclosed in a paper bag, and it is pressed
down to the bottom of the hole with a wooden stick, whilst a
piece of fuse also is inserted, extending from the charge well
beyond the hole. If the powder is loose, the miner carefuUy
wipes down the sides of the hole with a wet swab-stick, or with a
wisp of hay twisted round the Kcraper, in order to remove any
loose grains adhering to the fuse or the sides of the hole, and then
presses in a wad of diy hay, moss, or paper. A little fine tamping,
often the dust from boring a dry hole, is now thrown in and
lammed down with the wooden charging-stiok, and the same
process is repeated until an inch or two of tamping has been
introduced. The metal tamping-bar is now brought into opera-
tion, and the hole completely filled. If the hole is pointing
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2i8 ORE AND STONE-MINING.
upwards, the stuff for tampiog has to be done up in little paper
cartridges, which are poshed up and then tightly rammed.
The hole is now ready for finug. As a rule the safety^fuae is
not ignited directly. In open quarries a piece of touch-paper is
attached to the end of the fuse, so that in homing it will
eventually light the gunpowder. In mines a candle-end {amtff) is
fixed under the fuse by a piece of clay ; it is lighted to see that
everything ia all right and that it will bum properly, and then
blown out. The miner puts his tools out of the way of danger,
and after shouting " Fire " several times, sets light to the candle
and beats a retreat to some place where there is no fear of being
struck by the blast, and whence he can warn persons who might
otherwise walk into danger unawares. The candle bums through
the covering of the fuse, the fire reaches the core, aod ia soon
conveyed to the charge, which explodes and does the necessary
work.
The old plan of firing, which is still in use in many places,
consists in inserting the needle into the charge and then tamping
up the hole. Care is taken to draw out the needle a little as the
tamping proceeds, so as to prevent too much force being I'equired
for its final withdrawal. The small hole left in this way serves
for the inserUoD of a straw, rush, or series of ^mall quills filled
FiQ. 326. Fig. 317. Fio. 128.
m
with fine powder, which, like the fuse, reaches from the outside
to the charge. A short squib, which shoots a stream of sparks
down the needle-hole, is also used occasionally. The straw or
squib is lighted by some kind of slow match, made either by
dipping a cotton strand in melted sulphur, or soaking a piece of
paper or a wooden ludfer in the tallow of a candle; touch-paper
is also used for the purpose.
Nitro-glyeerine and nitro-cotton exploaves are fired by the
detonation of a strong cap, which is a small copper cylinder closed
at one end, partly filled with a mixture of fulminate of mercury
and chlorate of potassium. The amount of the fulminate required
depends upon the explosive, and the makers supply detonators of
different degrees of strength.
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BBEAKING GROUND.
a 19
The treble-strength detonators of the Nobel Company, BUpplied
for firing dynainite (Fig. 326), contain 0*54 gramme of the
mixture ; whilst the quintuple detonators, for blasting gelatine
(Fig. 227), have o'8 gramme, and the sextuple detonators i
gramme.
As full iuBtructions for use are issued with every packet of the
nitro-giycerine explosives, it is not neceeeaiy to repeat them here.
Fig. 328 shows a hole charged with two cartridges of blasting
gelatine, a primer (i.e., a small cartridge) and cap, and afterwards
filled up with water as tamping. The fuse is turned back and
fixed by a lump of clay, and the little candle-end is placed in
position for lighting.
Pfeiffer and Wiebenkel * propoee to make blasting with high
explosives safer and more efficient by interposing a column of
water between the charge and the primer. The concusdoa pro-
duced by firing a primer at the mouth of the hole is communicated
by the water to the charge, and is said to be sufficient to cause it
to explode. Of course the explosive used should be one not liable
to set free nitro-glycerine when in contact with water, as happens
with dyTiamite.
In a few mines where the straw still lingers in place of the
fuse, the detonator is squeezed on, sud then gently inserted into
the bole left by the withdrawal of the needle.
The workman employed in getting slate frequently dedree to
produce a rent without smashing the rock. He fills the hole,
FlQ. 329.
Fio. 230.
possibly 10 or 13 feet deep, almost up to the top, with a small-
grained gunpowder, and after ramming in a wad of dry moss and
an inch of tamping, sets light to the fuse in the usual way.
Provided his calculations are correct, the block is severed off
cleanly, and not broken up.
* German Patent Specifloatlon, No. 67,793, 1893.
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aao ORE AND STONE-MINING.
In quanying sandstone, Knox * has found it advantageous to
leave an air-chamber above tlie charge of gunpowder in the
rifting holes (Fig. 339). A is the powder, B the air-space, and 0 the
tamping lesting upon a wad of hay, grass, oakum, or paper.
Jot the purpose of firing several holes simultaneously, Messrs.
Bickford, Bmith & Co., the original inventors of the safety-fuse,
have brought out a special arrangement, the action of which is
rendared plain by the Fig, 230. An ordinary fuse is fixed into a
metal case called the igniter, from which a number of instantaneous
fusee convey fire to as many separate holes. It is found in prac-
tice that this fuse answers very well.
Iq mines where the atmosphere may be inflammable from the
presence of fire-damp, the burning fuse may become a source
of danger, and a special igniter has been devised by Messrs.
Bickford, Smith ife Co., to prevent accidents arising from this
cause. With the same object in view, frictional exploders have
been introduced, which ignite the charge when a string is pulled ;
but these belong more especially to the domain of coal-mining.
Ghai^ee may be readily fired singly or simultaneously with the
aid of electricity, either of high or low tension. Low-tension
fuses have the advantage that they can be tested with a weak
current and a galvanometer before use. If the galvanometer Is
not deflected, it is evident that the fuse is defective.
Fig. 231 shows a section of one<^ Brain's high-tension fusee. A
is a cylindrical wooden case containing a paper cartridge, B, with
Fio 231
an electric igniting composition, G, at the bottom. Two copper
wires, D D, enclosed in gutta-percha, £ E, reach down to the
composition, where they are about -^jg inch apart, A copper cap
or detonator, G, is fixed on the small end of the wooden case.
The insulated wires, D D, are long enough to reach beyond the
bore-hole. The ends of the wires are scraped bare, and one wire
of the first hole is twisted together with one wire of the next
hole, and so on, and finally the two odd wires of the flrst and last
hole are connected to the two wires of a single cable, or to two
separate cables extending to some place of safety to which the men
can retreat. Here the two cable ends are connected by binding
screws to a frictional electrical machine or a dynamo exploder.
The electricity passes through the wires, making a spark at
* See p. 162.
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BREAKING GROUND. azi
each break, and ao firing tbe electric igniting composition. The
flame flashes through the hole, H, and ignites the fulminating
mercury, the detonation of which causes the exptoeioa of the
dynamite, blasting gelatine, or tonite surrounding tbe cap.
The fuses supplied by Nobel's Explosives Company are some-
what different. Their high-tension fuse (Fig 332) consists of a
copper cap, A, into which has been {x«ssed a mixture of fulminate
of mercury and chlorate of potash, B ;
D D are two insulated wires, the ter- Tiqb. 232 ft 233.
minals of which are embedded in Abel's
flashing composition, F ; C is waterproof
cement, which serves to bold the wires in
position and to close the detonator. The
detonator and a few inches of the wire
are dipped in shellac varnish, so as to
make certain that no water can penetrate
during use. The ciirrent of electricity
produces a spark between the terminals,
igoitee tbe fli^hing composition, and fires
the fulminate.
The low-tension fuse (Fig 2^3) differs
in having a thin bridge of platinum wire,
E, soldered across the terminals. This
bridge is embedded in a composition, F, e d e d
consisting of gunpowder and gun-cotton.
When the current of electricity passes through the bridge, it
heats the wires to redness, igniting the composition and firing the
fulminate as before.
Electric firing has the great advantage of enabling the miner
to retire to a perfectly safe place before attempting to explode the
charge. This is important in sinking shafts, where the means of
eecape are less easy than in levels. A second advantage is the-
abaence of danger from a " hang-fire," an occasional source of
accident with the ordinary safety-fuse. On the other hand, in the
case of simultaneous blasting, it is impossible to be sure whether-
all the holes have gone off properly, and electrical firing was given
up in driving a level in &xony,* because unezploded dynamite
cartridges were so frequently found among the rubbish after-
blasting.
DBiyiZTG AND BZNEINa. — We now come to the apph-
cation of the hand and machine tools in driving levels and
sinking shafts.
A level or drift is a more or tees horizontal passage or tunnel,
irhilst a shaft is a vertical or inclined pit.
In driving a level by hand labour in hard ground, tbe first
1 K. SachwM ouf
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222 ORE AND STONE-MINING.
thing the miner has to do is to " take out a cut," i.t., blast out a
prehmioary opening in the " end " or " forebreast." The position
of this first hole is determined by the joints, or natural planes
of division, which the miner studies carefull; so as to obtain the
greatest advantage from them.
Thus Hg 234 shows a case in which, owing to joints, it was
advisable to begin with hole No. i, and then bore and
blast 2, 3, and 4, one after the other. The miner, as a rule,
does not plan the position of any hole until the previous one has
done its work ; in fact, he regulates the position and depth of
each hole according to the particular ciroumstances of the case.
In many of the drivages at the Feetiniog slate mtnee there is
a well-marked inclined plane of Reparation, known as the " clay
slant," along which the level is carried. The first holes are
directed towards this "slant," and most of them are bored up-
wards; in this manner wedge-shaped pieces of slate are easily
blasted out, and subsequent holes are bored so as to increase the
Fio. 2J4. Fio. 235.
size of this opening until the whole face of the "end" has
been taken away.
Though a vein and its walls may be hard, there is occasionally
a soft Uyer of clay (D D, D D, Fig. 235) along one wall {dig,
Oomwall; ^out^e, U.S.). The miner works this away with the
pick, and, i^ter having excavated the groove as deep as possible,
blasts down the lode by side-holes, and so pushes the level for-
At St. Just, in Cornwall, a narrow groove is w<n'ked out by
a fiat chisel called a peeker.
In sinking a shaft a similar method of proceeding is adopted.
A. little pit {gink) is blasted out in the most convenient part,
and the excavation is widened to the full size by a succession
of blasts, each hole being planned according to circumstances
This series of operations is repeat«d, and the shaft is gradually
deepened.
'Where boring machinery is employed, less attention and some-
tamee no attention is pud to natural joints, because, when once
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BREAKING GROUND.
233
the drill is id its place, it ia very little trouble to bore a. few
more holes, and tue work can be carried on according to a
syetem which is certain of effecting the desired result.
A common mode of driving in hard ground is shown in
Figs. i$6 and 337. Four centre holes are bored about a foot
Fig. 236.
Fig. 237.
apart at first, but converging till at a depth of 3 feet they are
within 6 inches or less of each other.
Other holes are then bored around them until the end is
pierced by twenty or thirty holes in all. The four centre holes
are charged and fired simultaneously, either by electricity or
by Bickford's instantaneous fuse, and the result is the removal
of a large core of rock. The holes round this preliminary
opening are then charged and fired, generally in volleys of several
holes at a time, and the level is thus carried forward a dis-
tance of 3 feet. If large holes are bored,
and if the ground is more favourable, ^"^' '31^-
fewer will be required.
The Halkyn Drainage Tunnel (Flints
shire) is being driven {7 feet high by
7 feet wide) in limestone by fourteen
holes for each advance; they are started _
with a 3^-inch bit, and finished with a Mm »^---^
2J-iDch bit. The holes are placed as
shown (Fig. 238), and are bored to a depth
of about 3 feet 9 inches each. They are
charged with dynamite, 25 lbs. being
used for the fourteen holes, and then blasted in foui' volleys : —
ist volley : — Nos. 1, 2, 3, and 4 together, which take out the
central core.
and volley : — The side holes, 5, 6, 7, 8, are fired.
3rd volley : — The top holes, 9, 10, 1 1, are fired, the fuses being
arranged so that No. 10 goes off before Nos. 9
and ti.
4th volley: — ^The bottom holes, 12, 13, 14, the fuses being
arranged so that No, 13 goes off before Kos. 12
and 14.
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324 OKE AND 8T0NE-MIKIHG.
KongUy Bpe&king:, it takes five hoars to bore the fourteen
holes, and five hours more to charge and blast them, and clear
away the rubbish.
Some engineers direct the four centre boles bo that they
meet at the apex of an acute pyramid, and, after all have been
charged with dynamite, only one receivea a primer and cap,
becMiM the shock of the explosion of this charge is sufficient to
fire the other three adjacent chargee simultaneously.
The preliminary opening lb not neceeaarily made in the centre
of a leveL Sometimes it is blasted out in the bottom or on one
side where there are natural joints to favour one of these methods ;
but when the rock is uniform it is best made in the centre, for
there the blasts can have the freest play.
At Bex, in Switzerland, where water power is abundant, a con-
siderable saving in cost has been effected by cutting a preliminary
groove in the centre line of the level by a houeymue.
Seven holes, each 3}- inches (8 cm.) in diameter, are bored 2
inches (5 cm.) apart in a straight line,
Fid £39 and the borer is then replaced I^ a
tool which breaks down the partitions.
A groove 2 feet 10 inches (86 cm.)
long and 3^ inch (8 cm.) wide is thus
formed, and after the boeseyeuse has
been removed, holes 1*2 inches (3 cm.)
in diameter are bored around by a
Ferroux drill as shown in the diagram,
F%. 239.
The holes A, B, C, D, E, F, G, are
blasted at one time, but the fuses of
A and B are cnt shorter than the
others, so that they go off first. The
result of this volley is the produc-
tion of a lar^ opening, and then the
firing of hole H, and subsequently of
the outeide hdes, completes the level for a length of 4 feet
(i-ao m.).*
In drivmg with the Ferroux drill in the ordinary
way, blasting out a central core, with dynamite,
the cost per metre of level driven was . . Ft. 73 4.0
By using the bceseyeuse to make a central groove,
and then the Ferroux drill for the remaining
holes, the cost per metre was only . . Fr. 39 40
Saving effected by the ose of the bosseyeuse , Fr. 34 00
The saving therefore is as much as 46 per cent. ; but in this case
the extra water power required is costing nothing.
• BosKt, Ifotiee tur Ui lalint* de Sex, Bex, 1S8S, p. 21.
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BREAKING QROUin).
aaS
Id unbmg shafta by boring machioes, operations are con-
ducted much in the same way as in levels, save of oourae that the
holes are directed downwards.
Figs, 240 and 241 are a plan and a section of a abaft which was
sunk at the Foxdale mines in the Isle of Man. About forty-five
holes were bored in the bottom of the shaft before the drills were
removed. Two of the holes (A and B), and occasionally four, were
Fta. 340.
FiQ. 241.
m
bored only 4 feet deep, and were blast 1 I ril na v f m 1. l!1iey
served simply to smash up and wean-^^ vuc vuic , uum the six
holes nearest the centre, which were 8 feet deep, were blasted
all together with Bickford's instantaneous fuse, and the result
was the removal of a large core, leaving a deep sink. The re-
maining holes were fired in volleys of four at a time in the
ordinaiy way. Id this manner the shaft, which was in hard
granite, was deepened at the rate of 3J or 4 ^thorns a month.
Tonite was the explosive used.
FIBB-SETTIM G-. —Though hard ground is almost invariaUy
nowadays attacked by boring and blastiog, the very ancient pro-
cess of fire-setting is not quite obsolete. The efiect of a fire is to
make a rock split ajid crack, and render it easily removable hy
the inck or by wedges.
Id 1876 1 saw a level in course of being driven in theKongabetg
silver mine, Norway, through crystalline schists, by this method.
A fire of logs of fir was made in the end, and the smoke was
conducted away to one of the shafts by an oval sheet-iron pipe,
2 feet by i foot.
It took eight cords of wood to drive i fathom of level, and the
rate of advance was 9 fathoms in 7 months. The fire was usually
made up twice in every 24 hours. In another part of the mine
an adit level was being driven at the rate of 2 fathoms a month,
with a consumption of 15 to 18 cords of wood. In this case an
arch was built in the roof of the level to fonn a passage for the
smoke, and the iron pipe was used near the end.
In driving in hard rock in the gold mines of Korea,* a pile of
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326 ORE AND STONE-MINING.
vocd is set on fire near tlie face of the tunnel, and allowed to
bom for 24 hours. The place is then allowed to cool for three or
four days, when the minerB return and break down the loosened
rook with hammer and gad. Fire-setting is also employed in
mining j&de in Burmah,* and in quarrying stone in India, t Lastly,
the Siberian prospector avails himself of the softening action of
firo for sinking small trial shafts through ice and frozen ground
in search of auriferous gravel.
EXCAVATZKa BY WATSXL— We torn natuially from
fire, one of the four elements of the andents, to another, water,
as a means of breaking ground.
Watw can be applied either for dissolving the rock or mineral,
or for loosening it and then carrying it away.
There are two cases in which water may act as a solvent — viz.,
common salt and copper. It is used, as we shall see in speaking
of the methods of working, to dissolve out salt from saliferous
rocks, and it can also be employed for excavating upwards or
downwards in rock-salt. For excavating upwards ("putting up
a rise"), a jet of water is made to play upon the roof of a level,
and means are taken to carry off the brine in troughs (^launders)
without dissolving away the floor. For sinking from one level to
another, a bore-hole is first put down, and this is gradually
widened by the solvent action of water.
When cJd workings containing the sulphides of copper are left
exposed to the action of air and the percolation of rain water,
part of the copper becomes converted into a soluble sulphate, and
water pumped up from the mine may become a profitable source
of the metal. This is the case at Farys mine in Afiglesey.
There are also two cases in which water is mode to act as a
loosener and conveyer— viz., for working day and gold.
A stream of water is turned on to the deposits of china clay,
and, aided by work with a pick, it carries everything to settling
pits. The most important application of water is the process of
washing away thick beds of aunferous gravel, known as hydraulic
mining. A huge jet of water under pressure is made to play
against the bank of gravel, undermine it, cause it to fall, and so
thoroughly disint^tate it that everything save the largest
boulders is carried away in the stream. Full details of these pro-
cesses will be given in Chapter TI. (Exploitation).
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CHAPTEB V.
SUPPORTING EXCAVATIONS.
Tariona kinds of timber used for Bnpporti — PraserratioD of timber from
di7 rot.^Toola. — Timbering levels, shafts, and woTking planes. —
Mbbodij, brickwork and concrete for levels and sbaftB, — Iron snd
steel snpports for levels, shafts, and working pUoes.— Special pro-
cesses for sinking through wateiy strata : boring, oompressed air and
freezing methods.
Excavations made in bard ground will frequently stand with-
out any props wbatever for aa unlimited time, but tbe miner
bos generally to deal with rocka which sooner or later give way
unless supported. Consequently it becomes necessary to adopt
means of securing the underground passages and working places,
«ither during tbe process of szoavation, or at all events very
soon afterwards.
Tbe methods of securing mining excavations may be classified
according to the materials uned for tbe protective lining, viz.,
timber, masonry, iron, or steel.
TIUBXEl. — In Europe, varieties of the following kinds of
trees are those most frequently employed underground : Oak,
larch, pine, fir, and acacia.
The oak is especially adapted for mining purposes on account
of its strength and its durability. It will resist alternate
exposure to wet and dryness, and under water it is almost im-
perisbable. In England we have two principal varieties, Qveratu
robur peduneulata and Quercut rotmr eeeeiiiflora.
Tbe conifers, larch, pine, and fir, have the advantage of
furnishing straight timber, of even grain, comparatively light,
easily woriced, having few branches, and less expensive than oak.
The larch {Abies larix or Zarix Ewopaa, D. C.) is an excellent
jnining timber. Tbe large amount of resin it contains seems to
act as a preventive against decay. It is tough and strong, and
lasts a long time, even when alternately wet and dry.
The American pitch pine {Pinwa rigida) is a timber largely
imported into this country for mining purposes, and it is used
not only for securing sbafta and levels, but also for pump-rods,
lodges, sides of ladders, ix. It is remarkable for its pwfectly
straight growth ; it is hard, highly resinous, and very durable.
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328 ORE AND STONE-MINING.
The Scotch fir (Pinut aytveatris) ia a tree that fumishee a great
deal of miniag timber. The British-grown timber is largely
used for props, whilst balks imported from Norway and Sweden
serve for heavy work in many mining districts.
The spruee fir [Abies exeeha) is not a timber to be recom-
, mended for mine supports where durability is required.
The acacia has the property of resisting the efiects of bad air
and high temperatures very much better even than oak.
Mr. Femow* gives the following list of the various kinds of
mining timber which are available in the United States, each
series being arranged in order of durability, beginning with the
treee most adapted to resist decay.
BisTEBN Buiaa.
Conifers. — Bed cedar (/unip«-u» FiVyiniana, L.) ; White cedar (CAamieeu-
jKtrii iph(Broidea, Spach.) ; ^boi vitte [Thuga occidentalii, L.) ; Bald
cyprcBB {Taxodium diiliehum, Bich) ; Long-leaved pice (Fintu pmuMtria,
Miller) : Red pice {Pinua rainoia. Ait.) ; Cuban pine {Pinus Cuheiuit,
Griseb.) ; Bhort-leaved pine (Kntw mitii, Micbi.).
Broad-leaved trees.— White oak {Q,uerca> aiba, L.) ; FoBt oak (Qaerau
obttuiioba, Miohz.) ; Chestnut oak {Qaercat printu. L.) ; Live cak (QtMrnu
mrtni, Ait.); Basket oak (Qucrcui Michauxii, Nntt.) ; Burr oak [Querrmi
macrdcHTpa. Michx.) ; Oaage orange (Mruiara oumn'icci, Nutt. ] ; Hard;
catalpa (Caiaipa tpecioia. Warder); Black locust iSobinia ptrvdacacui,
L.) ; Honey locust {OlediiicAia triaeanthoi, L.); Bed niiilberr7 [iforaindtra,
L.); Cbestaint {Oailarua vuigant, var. Amerieana, A.D.C.)
BOOKT MoCtTTAIN RBQION.
: (^QtuTcta macroearpa, Michz.)
Pacific Slope,
Tew {Taxut brtvifolia, Natt.) ; Redwood {Sequoia ttmpervireni, Snd-
lioher); Lawscn's cypress {C tunnieeyparU Lamioniana, ParL) ; Canoe
cedar {Thuya gigantea, NnCt.}; Dooglas apnice {Plaidiittitga DoagUini,
Can.); Western larch {Larix occuUnialii, Hatt.y, Live oak ((^rcut
ehrymtpii, Liebm.) ; Poet oak {QatrtMi Oarryana, DougL).
The Douglas epruce, or Oregon fir or pine, is not only
used in America, but also exported to Australia. It is a very
straight wood, of even grain ; it has the disadvantage of ea^y
takiDg fire-
In Australia, the native woods are commonly used for "''"''ig
purposes, and among them different species of Eucalyptus are
specially prominent.
The Jarrah {Evcalyptaa marginaia) is a native of Weetern
Q Forestry," Trant. Am, Iiul.
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SUPPORTING EXCAVATIONS. 229
Australia. It gives a red, heavy, intensely hard wood, which is
difficult to work with oidinary tools. It resists dec&y im a r&>
markable maimer, in fact it is practically indestructible ; the white
Aut and the " teredo navalis " will not attack it. Up to the present
time there has been little need of mining timber in the colony of
which it is a native; but it is exported to South Australia and
New South Wales, and used for shaft-frames and other special
purposes.
The grey or white iron-bark (Eueah/ptua cr^ira, F. v. M.),
&nd the red or l:dack iron-bark {Eueaiyptiu leaeoxylmt, F. v. M.),
both give hard, heavy, strong, and durable timber, Mid are among
the most useful of the forest trees in Australia.
Orey box {Evcaiyptiu largi/lortna) is a hard, tough, duraUe
wood which lasts well undergrouud. The young trees supply
much prop timber in certain localities.
Stringy bark {Evccdyptwa obiiqva), posaeasas similar good
qualities; and it is imported into Australia from Tasmania if
the supply of the native-grown timber is insufficient or leas easily
■obtainable. It is employed as sawn timber, or split, and the
email trees make excellent props.
Among other species of Eucalyptus may be mentioned the
slaty gum {E. bicMor, A. Cunn.), and bloodwood, {E. coryinboaa,
SmS, both strong and durable and used for railway sleepers.
liie prickly leaved tea-tree {Melaleuca armiUaru) gives a
bard, strong, heavy timber, lastiDg well underground.
New Zealand can boa^t of the nutgnificeat Eauri pine
^Dammara Aiutralia), a slow-growing tree, some living examples
being estimated to be 2000 years old.* It contains a fluid resin
which oozes out from every part, and hardens into large masses
of opaque gum. It is light, elastic, even-grained and strong.
Besides being used for timbering mines in New Zealand, it is
«xparted to Australia for the same purpose.
Matai {Podocarpu* femiginea), a reddish-brown, moderately
bard wood, Miro (Podocarptu apicata), and Bewarewa {Knightia
laadta) may also be mentioned among the New Zealand mining
timbers.
In Japan the levels are sometimes timbered with bamboo.
FreBerration of Timber. — Most authorities consider that the
best time for felling timber is winter, when the wood has the least
amount of sap in it, because fermentation of the sap is one great
cause of decay. For this reason also, timber should be seasoned
before it is used ; that is to say, it should be allowed to dry gradually
and so lose the sap by evaporation. Femowf says ^at proper
seasoning b more important than the time of felling. As regards
* Lulett, TinSier and Timber Tru», London, 1S75, p. 296.
t Op. cit. and " Relation of Bailroads to Foreab SappUea and Forestrj "
BuOttin Xo. I, Foretlrg Dieuion, Department 0/ Agrieuiture, U.S-A. Waah-
iiigt«n, 1887. pp. 37 and 67.
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330 ORE AND STONE-MINING.
the removal of the bark or not, there U a difference of opimoD,
but it certaioly facilitates the seaaonin^ ; and in the case of oak
the bark may be taken off for gale by the owner of the plantatiooB,
before he dispoBee of the timber to the miner. On the whole it
seems advisable to remove the bark, and for two reasons — (i) less
liability to rot, and (a) earlier indications of incipient cruehing.
When stored at the mine, timber is beat preserved under cover,
protected from wind and weather, but with ample acceas of air ;
and it ia important to remove all decaying wood, whether Ic^s,
diipe, or sawdust, and destroy it hy fire, 80 as to prevent the
spread of the contagion. The timbo- should lie upon supports
and not directly on the ground, and the pieces should not be
placed too close together.
According to LAfilett,*' " the approximate time required for
seasoning timber under cover, and protected from wind and
weather, is as follows : —
O^. Fir.
Pieces i6 to it ionhes equ
Timber is often f onnd to decay very rapidly in 6<uue mines, or
in certain parte of a mine, owing to the spread of what is called
dry rot. This is a white fungus which grows over the timber,
and causes the woody fibre to decompose and become so soft and
rotten that a knife or pick can be rnn in with the greatest ease.
Various methods of preventing dry rot have been tried with
more or less success. Good ventilation is all-important, for
timber is found to became affected most rapidly in places where
the air is foul or stagnant. Water has a decided preservative
effect, GO much so tl^t arrangements are sometimes made for
causing it to trickle down continuously over the timber in a
shaft, or to form a spray in timbered levels. Probably the water
acts by washing off the spores of the fungus as fast as they are
deposited upon the fcunber, and also by cleansing the atmosphere
and keeping it cool.
Mine timber is also occasionally treated with antiseptics, such aa
brine (with or without chloride of magnesium), borax, creosote,
carbolineum, coal-tar, corrosive sublimate, chloride of rinc, sul-
phateof idnc, sulphate of copper and sulphate of iron ; but far less
attention has been given to this subject by mining than hj dvil
engineers, to whom the duration of railway sleepers (tiM, U.S.A.)
is a matter of much importance.
Treatment with a metallic salt is preferred to creosoting, if
the timber is at all exposed to the risk of catching fire.
" Op.cit. p. 316.
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SUPK)RTIHa EXCAVATIONS. 231
The timber is treated in one of the following ways : —
(i) SU^Bg.—Tbe timber Is simplr placed in the preEermtiaii solntioo,
and allowed tu absorb what 11 can.
{i) Sydrottatie Proce**. — The preservative Bolatioa U foioed la by
bydrostatic pressure.
(3) Focuum Procat. — The timber is placed in boilers, and steam ia
admitted ; the air and Tapouis are then ezhaoated, and a preservative
tamed In qnder pressure.
(4) Banting, i.«., applicatton with a bmsli.
It was found by ezperiments carried on at Commentry dvuing
along seriesof years, that one of the beet metfaoda was soakiiig the
timber for twenty-four houre iu a strong eolation of sulphate of
iron (green vitriol). The total coat was only ^d. per yard of prop,
whilst the timber lasted eleven times as long as when this simple
treatment was omitted. " Carbolineum " is a patent preparation
laid on with a brush like paint, which is well spoken of by the
mining officials at Saarbriickeu.* The cost of two coats of the
preservative material on a prop 8 feet long by 10 inches in
diameter (3'5 m. by 35 cm.) is about 7^d.
The duration of a prop, or other piece of timber, is not the
only point to be considered in deciding whether it is worth while
paying the cost of some preservative treatment. The expense of
the labour in the renewal of unsound timber, such as the catting
of fresh AtfcA«s, must not be overlooked.
TooIb,— Timber is used in various forms — either whole and
merely sawn into lengths, or hewn or sawn into square balks, or
sawn in half, or sawn or split into planks of different thicknesses.
The tools used by the miner for shaping the timber are the
saw and axe ; in addition he requires a measuring staff, a sledge
or a wooden mallet for driving the timber into its place, a hammer
and " moil " for chipping out recesses or niches (AitcA««), plumb
line and level.
The latos vary in different countries. In Great Briton the
timberman's saw is the ordinary band-saw of the carpenter,
though a cross-cut saw worked by two men is used for cutting
large props or balks. In the Harts the timberman uses a saw
somewhat resembling our cross-cut saw in shape, but smaller in
size, and having the toothed edge curved, whilst in Saxony a
frame saw is preferred. All large mines have a circular saw, and
some are provided with special machines for cutting the joints of
supporting frames.
fha aax varies in shape more according to the fancy of the user
than any special difference in the purpose for which it is used.
The moU is merely a pointed steel bar. In order to ascertain
the length required for a piece of timber to fit a given place, the
timberman uses a meanerinff staff", consisting of two bars of wood
• ZtittdiT.f, B- H.. u, S^Wetin, voL xxxvIiL, 1890, p. 365.
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332
ORE AND STONE-MINING.
whicli ore made to slide upon each other, and then fixed in any
position by a thomb-ecrew. One end is often rounded so that it
may reach to the bottom of the niche (hitch) which has been out
in the rock. The plumb line an3 level need no descriptuin.
The principal lands of excavations in mines are levels, shafts,
and ordinary working places. These will be taken in order, and
the methods of securing them dealt with briefly.
liOvelB. — Though a level is an excavation of a very simple
nature, the methods of timbering it vaty conaderably, because
the parte requiring support may either be the roof alone, or the
roof and one or two sides, or the roctf, sides, and bottom.
If the roof only is weak, as is the case with & soft lode between
two hard walls, a cap with a few boards resting on it (Fig. 242)
Fia. 142-
Fio. 2^3.
is sufficient to prevent falls. If one side is weak the cap must
be supported by a side prop or leg (Fig. 243), and very often by
two legs. The form of joint between cap and leg are numerous
(Fig. 344), depending to a great extent on the nature of the
Fto. 244.
FlQ. 245.
Fig. 346.
rmr
pi«ssure, whether coming upon the top or tddes, and also on the
shape c^ the timber, whether round or square. With round
timber the top of the leg may be hollowed out as shown in
Fig. 245 a; l"*** occasionally the joint is flat, and a thick nail
or noff is put (Fig. 245 b) to prevent the effects of side pressure,
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SUPPORTING BXCATATIONS. 233
or, better, a. piece of thick plank ia nailed under the cap
(Fig. !46).
Where the floor of a levd is soft and weak, a sole-piece or till
becomes necesaaiy, and if the sides or roof are likelyto f fdl in, a
PiQ. 247.
€
lining of planks or poles is used (Fig. 246). "Homed seta"
(fig. 247)*are ua^ul in loose ground.
r^. •48 shows the special system adopted on the Gomstock lodef
for some very heavy ground. The outer planks {lagging) are put
dose together, and the method
of jmnting has been carefully de- Fia. 249.
signed bo as to prevent any yield-
ing under the enormous pressure
to which it is subjected. These
levels are 6 feet high inside the
timber.
As an instance of timbering on
a much larger scale, I give a re- 1
presentation of the supports at I
lUo Tinto, Spain (Pig. 349 ) ; the |
height of the level from the
groundsill (a) to the cap (e) ia 12
feet 7 inches (3*85 m.), so as to .
allow the passage of locomotives. .
In driving levels for the deep '
gold-bearing gravels in the Cari-
boo district, B.C.,{ spruce fir i to 3 feet in diameter, simply
barked, is used for making the sets. The lagging is in piecea
fHagae, "Mining Indastry," UnUed Siatet Oeologieal Mxxhraium of tlie
Fbrtala FiiraiUl, vol. ilL, plate Ir., p. 113. Waahlngtoo, 1870.
i DawMD, "Q«ueralNote on the Mines and HinuaJsof Econoinio Value
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234
OEE AND STONE-MINENG.
4 feet long, 5 inches wide.ands inches thick, and is split out of logs.
The ground ib bo he^Tj that the frames («(*) are only a few inches
apart in some places. Where the gronnd isvery wet, spruce hiush-
wood is placed behind the lagging.
In the Day Dawn mines in Queensland,* the gold vein some-
times attains a width of 60 feet ; the hanging wall is not strong,
and large portions of the lode itself are apt to slip away.
Via. 250.
Though the levels could be driven without difficulty, it was found
impoeeible, with the ordinary methods of timbering, to keep them
open permanently after the vein had been worked away, and the
whole pressure of the heavy ground on the hanging wall had to
be supported. At last the so-called "pigsty" method was tried,
and it has been found very successful. It consists in piling up
logs 4 to 8 feet long, two by two, crosswise, and so building a
support which covers a comparatively large area.
Figs. 250 and 351 represent the pigsty timbering; the former ia
of British ColumbiH," Geol. Survey, Canada. Reprinted from Canadian
JhiN^ Sailvxn/ Bepcrt, 1877, p. 8.
* This deaoription and the flgarea have been kindly aapplied by Mr.
Josepli Shakespear, one of theOoveiimiBiit Inapectoia of Uinea in Queens-
land.
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SUPPOKTING EXOAVATIONS.
235
a seotioQ along the line of dip, the 1att«r along the line of strike.
As the drivage progressee, strong sUls, i o to 1 2 inches in diameter,
are laid along the floor of the level. These sills may be as much
as 35 feet in length, and two of them are laid under eaoh row of
sties, which are placed about 6 or 8 ft. apart in the direction
ol the level. The number across the level depends upon the
width of the lode, and the spaces between the rows of pigsties
ffxnn the roads for the waggons. The cap-pieces are made of
'^<^^
Scale
lUCTRC 0 I a 3 « S 6 7 METRES
timber 15 inches in diameter, and they rest upon the pigsties.
Upon the cap-pieces comes a row of poles, which support the
deads when the lode is worked away above.
Where the width of the lode ia not too great, the sills are dis-
pensed with ; the ground at the bottom of the level behind the
end is excavated, and the pigsties are built up from the foot-
wall. Consequently, when the lode is removed by the workiDgs
below, the level is not affected because the timbering is supported
from the undisturbed footwall.
When sills are used in a very wide lode, pigsties resting upon
the footwall are built up whilst the ore is b«ang excavated, and
they are arranged so as to come exactly under the sills and caxry
their weight.
This method of support requires a great deal of timber, but
it has the advantage that the small logs used for the pigsties are
inexpensive and easily handled, compared with huge balks
required with the other systems.
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236
OEE AND STONE-MINING.
If the ground is loose so that the roof or sides, or both, will nm
in imleee Bupported, the method of working called tpiUing, tptHng,
or poling is pursued. It couBistA in snpportiug the weak parte hj
boards or poles in advance of the last frame set up. The process
may be described as pushing out a protecting shield in very
narrow sections, one at a time. The poles or boards (Jatiu) are
driven forward by blows from a sledge, and the ground is then
wco'ked away with the pick ; this removal of ground enables the
laths to be driven in further ; the pick is now once more called
into requisition, and by successive small advances the shield of
poles or boards is extended a distance of 3 or 4 feet. Fig. 252
shows one of the advance polee partly driven, with the front end
FiQ. 253.
FIO. 253.-
resting upon a set of timber; the pole behind it is in its final
position. The section, Fig. 253, explains that the lower set of
poles, those which are in the course of being driven, have room
enough to slide ou top of the cap, owing to the blocks placed
upon it being elightly thicker than their diameter.
In runmng ground it is necessaiy to have the laths fitting
closely together, and the working face must also be supported by
breaat-boardt, kept in place by little struts resting against the
nearest frame. These are removed and advanced one by one,
after the laths in the roof, sides and bottom have been driven
beyond them.
In a few instencee the end of a level in running ground has
been kept up by covering the entire working face with wooden
wedges ; en advance was gradually efilected by driving them in
with a heavy eledge. The sides and top of the level were pro-
tected by laths in the ordinary way.
Shafts. — 'The timberiog required for shafts varies according to
the nature of the ground and the size of the excavation. A mere
lining of planks set on their edges (Fig. 254) suffices for small
shafts, comer-piecee being nailed on so as to keep the successive
frames together.
The usual method of securing shafts is by mM ot frames. £ach
set consists of four pieces — two longer ones called waU^>latee, and
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STTPPOKTING EXCAVATIONS. 237
two shorter ones called end-piecea. They are joined hy aimply
halving the timber at each end, as Bhown in Eig, 355, the wall-
pl&te being made to rest upon the e ad-piece, though this airange-
ment is sometimes reversea. A more complicated joint (Fig. 256)
is often preferred. The separate frames are kept apart by distance
pieces (ttuddla, Cornwall; jogit, Flintshire; poeta, U.S.), and
loose ground is prevent«d from falling in by boards or poles
outside. The length of the distance pieces must depend upon
the solidity of the ground. If the ground is very weajc they are
not used at all, and the successive frames are put in touching each
othw ; in loose ground near the surface the distance between
the frames may be iS inches, for instance, and then increased
gradually to 4 or 5 feet when the shaft has penetrated into harder
strata.
The end-pieces are sometimes made long enough to project a
foot or eighteen inches beyond the wall-plates, and rest in niches
in the rock. Another plan is to insert bearera at regular intervals —
say every 30 feet — under the end-pieces. The bearers are generally
of oak, and in a shaft of medium size pieces 12 inches by 12
inches are taken, and cut four or five feet longer than the end-
piecee. They therefore project 2 to 2 feet 6 inches at each end
into solid ground, and decidedly add to the security of the timber
The sides of the shaft are further prevented from falling in by
planks which rest against the wajl-plates and the end-pieces.
During the process of sinking, the last frames are kept in position
by strong iron clamps, and when a length of 10 or 1 2 feet has been
completed, planks (taiAinga or Uatinga) are nailed on inside, stretch-
ing over several frames and so binding them all together.
This lining of a shaft may be regarded as a very long box,
with strengthening ribs at short intervals. As shafts are
frequently used for the several purposes of pumping, hoisting, and
affording means of ingress and egress by ladders, it beoomes
necessary to divide them into compartments. Pieces of timber
parallel to the end-pieces (&unbm« or davidiaga) are fixed across
the shaft, and serve to stay the wall-plates, to hold the guides or
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238
ORE AND STONE-MINING.
conductors, to support planks {eating boards), which are nailed to
tham 80 as to form a continuoas partition or brattice, aud to
assist in carrying the ladder platforms.
The magnificent timbering of some of the uhafts on the
Gomstock lode is described by Ur. James D. Ha^e' aa follows : —
" The timbering consists of fiamed sets or cribs of sqtiare
timber, placed horizontally 4 feet apart, and separated by uprights
or posts introduced between them. Cross-timbers for the par-
titions between the compartments form a part of eveiy set. The
whole is covered on the outside by a lagging of 3-incli plank
placed vertically."
Figs. 257, 258, and aS9,copied from Mr, Hague's plates, illustrate
this method of timbering. Fig. 257 is a plan of the shaft. "S S
Fig. 257.
are the longitudinal or sill-timbera ; T T, the transYerse end
timbers ; r, guide-rods between which the cage moves ; g, gains
out in the sill-timbers to receive the ends of the posts. The
sheathing or lagging is seen enclosing the whole frame."
Fig. 258 is a tranaverse section through the partition-timber
^dividing) P, of Fig. 257, "between the pumping compartment
Fig 358
and the adjoining hoisting compartment, looking towards the
latter In this figure, G 0 are the ^ts; S, the sill-timberB;
P, the partition-timbers, the ends of which are framed with short
• " Mining IndoBti7," UniUd StiOa Oet^ogicaiEx^ationofthtFortittk
AhmUcI, vol. Hi. p. 103.
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STJPPOKTING EXCAVATIONS.
^39
teaODS that are received in gains cut in the sill-timbers and the
ends of the posts; r, guide rod; I, lagging or sheathing."
Fig. 359 is an end view of the frame shown in Fig, 257,
" The single piece T forms the end, while the doable pieces P,
forming the partitions, are seen beyond. The out«r timbers of
each set — that is, the two sides and ends of the main frame — are
14 inches square; the poets, ten in number, four at the corners
and two at each end of the partitions, are of the same size. The
dividing-timbers forming the partitions are i z inches square."
The pigsty system of supporting ground has been applied to
an incUned shaft at Day Dawn* Mine in Queensland, in which
the ordinary B3rstem of frames was proving inadequate. In this
case the shaft had been sunk on the inclined lode ; the ore had
been removed on each side and replaced by " deads," and the
ndes and roof were supported by ordinary frames and laths. The
manager took out a strip of deads on each side of the shaft, and
ag soon as sufBcient room had been made, he built up a couple of
pigsties, and then another two, and so on. The space between
them served as a passage (iriivse) for winding-up the deads as the
work progressed downwards. The ends of the long horizontal
balks of iron-bark timber (caps) stretching across the shaft were
made to rest upon the pigsties, and upon them were placed poles
which supported the roof {Aanging-ioall). Since this method has
been adopted there has been no trouble with the shaft. The
subsidence of the hanging-waJl has been going on, but the pigsties
FiQ. 360.
yield to the movement without becoming crippled or useless.
Occasionally a cap piece breaks in the middle, in spite of its great
size, but it can easOy be renewed.
. As an esAmple of another large shaft may be mentioned the new
meet luspectoT of Hinea, Qaeens
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240 ORE AND STONE-MINING.
smkbg at the Calumet ^d HecU mines* (Fig. 260), which is ex-
pected to strike the copper bed at a depth of 3325 feet from the
surface. The shaft is rectajigdlftr, 23 feet by 13 feet 6 inches
within the timber, and divided into six equal compartments, 7 feet
by 6 feet 3 inches within the timber. A andf {Kg. 260) are for
receptacles for winding rock, C and D ior cages for raising and
lowenng men, timber, &c. ; E forms the upcast air^way, and J** is
for air-pipes, &c. The frames and the dividing-pieces are made
of southern pine, 1 3 inches by 1 2 inches, and the whole is sur-
rounded by a close lagging of 3-iuch plank.
At Glausthal in the Eartz, round timber is generally used, and
special means are adopted for resisting the heavy pressure of the
ground upon the wt^-plates.
In Fig. 361 a a are the wall-plates, made of timber i foot in
fc
H
7
diameter; bb, the end-piecee; te, the studdles, which are 18
inches long.
The end-piecee are not halved as in Fig. 255, but are slightly
wedge-shaped, so as to preserve their whole strength for prevent-
ing the wall-platee from being squeezed together. However, reli-
ance is mainly placed upon frameworks of round timber, 15 inches
in diameter, placed at the ends and near the middle of the shaft,
and shown in elevation in Fig. 362. Each framework consists of
two pieces, 18 to 20 feet long {waU-poste, c c), kept apart by dia-
gonal struts (st«mpde or tpar-tiTnitera, d, d', c2"). The foot of the
lowest stempel fits into a hitch cut in the long wall-post, whilst the
head is merely hollowed out to suit the curvature of the opposite
wall-post. All the other st«mpels are cut out in this way at both
ends, and when the bottom stempel has been put in, the others
are veiy speedily fixed one above the other. If neoessaiy, a strong
bearer, h, is put in &om time to time under the wall-posts, and
projects a foot or 18 inches into the ground on each side of the
shut ; thin poles placed vertically and horizontally,/ and g, pre-
vent loose stones from falling in.
* Enginttring, Tol. I., 1890, p. 553.
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SUPPORTING EXCAVATIONS. 241
Special ezcavations have to be timbered according to oiroam-
Btancee ; thus a chamber for a water<wheel at Clausthal in the
Harts was made decagomd (Fig. 363). The main horizontal pieces
at the side were of lo-inch round timber cut at the ends to the
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■,42 ORE AND STONE-MINING.
|«oper angle ; behind them came half-round timber, trees i a or
14 inches in diameter sawn in half, arranged vertically, and
finally a backing of common planks; the successive horizontal
frames were kept apart by studdlea, one at each end of each aide
of the polygon. . . j . -,7-
SpiUiug. — When ground is loose, recourse is had to a wpiumg
process like that deaoribed for levels. Steong balks of timber are
Via. 264.
«. h cSj
-
«
PLAN
<Si I «j
fixed at the surface or in solid ground in the shaft, and the first
frame is supported upon these bearers ; the next frame is hung
from t^e fifst, the third from the second, and so on until the loose
ground is passed.
In Fig- 365 a a are the " bearers," which are made to project a
couple lU feet into solid ground ; upon them rest the end-^pieces
( h (Uga. 364 and 265), halved at the ends bo as to support the
two wsJl-platea c c, e e are two rods of z-inch round iron, which
hold up the end-piece d of the second frame or " set of timber."
They u« fixed ti^tly by means of cotters. Thewall-pIates/Zof
the second frame rest upon the end-pieoes in the \isoaX way, and
when it becomes necessary to put in a third set or frame, the end-
jneces g are hung by oottered bolts from the frame above, d; hh
are the wall-plates. The fourth frame with its end-piece i and
wall-plates j follows in the same manner ; therefore, until the
pressure of the ground comes into play, the bearers a a are carry-
ing the whole weight of the timber. The pieces k k, known as
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SUPPORTING EXCAVATIONS. 343
" l&tha," are made of 2-inch plank, 9 or to inches wide, sharpened
at the ends ; they Berve to keep the loose ground from falling
into the shaft ; 1 1 are the so-oilled " tailinga " which keep the
laths in position. The lath k, is one which is being put in ; it
has to be stnick with a heavy sledge until it makes its way into
Fio. 26 J. Sectional elevation along line AA ot Fig. 264.
-f^ £fc_
iia loose giound. If very heavy blows are required, the heed of
the lath is protected by an iron shoe.
The piece m is a stay put in for the purpose of keeping the aet
or frame in its place until the laths have been driven. The
framee are kept at the pi-oper distance apart, and the timber
-strocture is stifEened by the usual comer posts n n (atuddlee).
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^,le»* gether
Co»^
244 ORE AND STONE-MINING.
Kie loose ground is excavated gradually, while each protecting
ah^li of pUnks is in process of being driven down, and in due
course another frame is
Fio. 266. hung on, and the opera-
j^jl, tiona of driving laths and
"* '■' excavating are repeated.
At mines on the Com-
stock lode, the bolts for
keeping the frames to-
'■ gether are made in two
parts, with a tightening
screw in the middle ; great
firmness is secured in this
manner.
Working Flaoes. —
The timbering of working
places varies very greatly.
The simplest case is that
of a horizontal bed. Here,
props put in vertically of ten
suffice to support the wmght of the roof. The addition of a lid, a.
flat or slightly wedge-shaped piece of board at the top, extends the
bearingsurface, and, by presenting a smooth face to the top of the
prop, enables this to be forced in more firmly into position than it
could be against a rough roof. It also yields a little to the pres-
sure of the roof, and lengthens the life of the prop in this way.
When the bed is inclined, the props are not set quite at right
angles to the plane of bedding ; one reason for tliis is that if so
set they might be easily knocked out by an accidental blow from a
falling stone.
M.r. Sawyer* has made out a table showing the deviation from
the normal which should be given :
BttorUDdoMtorPotti.
DlpafSeun.
HlalmDis.
UuJmam.
6
12
J
;
18
3
24
4
30
3'
s
36
2°
6
42°
2°
7
4r
3°
8
54°
3°
9
and upwards
' Acddentt in MiiKi/rom Falii <^ Roof and Sidet, Jjondon, 1886, p. 50.
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StrPPORTING EXCAVATIONS.
245
I^. 266, copied by permiseioti from Mr. Sawyer, ie an inBtaiice
of a prop aod Ud for worHng in a bed of clay iroDstooe.
Logs laid two by two crosswise (ehoeks or eriha), the pigsties
of the Australian miner, form efficient supports. Fig. 267 repre-
sents the maimer of usiuf; them in a bed of potter's clay ; fig. 26S,
one of the huge structures which may be seen in the Wieliczka
salt mines ; and lastly, Fig. 269,* the method adopted at Day Dawn
gold mine, Queensland, in the case of a vein. The pigstiee for
sapporting the banging wall are built up at intervals in the work-
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246
ORE AND STONE-MINING.
ing places {ttopea), and then filled up with rubbish (deadt, muUoek).
The pigstiee on tne foot-wall aerre to keepup a portion of the vein
until it is time to break it down. Square timber is used for
chocks as well as round.*
According to Heathcote, the " square set " S3^tem of timbering,
so largely used in the United States, is not an invention of
American origin, as is usually supposed. It appears to have been
Fia. 270.
FiQ. 271.
known in Australia as long ago as 1854. The manner in which
it is employed in Nevada for working away the soft " bonanzaa,"
or ore-bodies of the great Comstock lode (Kgs. 270, 271, and 272)
is well described by Hague.f It consists in framing timbers
together in rectangular sets, each set being composed of a square
base placed horizontally, formed
Fio. 272. of four timbers, siUa, and cross-
pieces, 4 to 6 feet long, framed
together, aurmounted by four
posts 6 to 7 feet high, at each
comer, and capped by a frame-
work similar to that of the base.
These cap-pieces, forming the top
of any set, are at the same time
the sills, or base, of the next
set above, the posts, as the sets rise one above the other in the
stope, being generally placed in position directly over those
below.
"The timbers are usually of 13-inch stuff, square hewn or
sawn." Each post haa a tenon 9 inches long at the upper end,
and a tenon of 2 inches at the other end, which fit into mortices
in the cap and sill respectively ; and " the sills and caps have
short tenons on each end, and shoulders cut to receive the ends
of the post and the horizontal cross- pieces." The walls of the
excavation are sustained by a lagging of 3-inch or 4-inch plank.
* DiecuBsiou upon Messrs, Jamieson and Howell's paper, " Uining aad
Ore-treatment at Broken HUl, N.S.W." Min. Proc. Intt. C.E.,toL cxiv.,
Session 1S92-93. Part IV.
t Op.cit^ p. 112.
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SCPPOETING EXCAVATIONS. 247
The whole width of the ore-body is stoped away at oiice,and its plaoe
sapplied by timberiog, and finally the vacant space is filled with
waste rock derived from dead work in the mine car from spedal
excavations — underground quarries in fact — in barren ground.
The stoping is carried on overhand, starting from an intermediate
shaft or winze, and Fig. 372 will explain how the different frames
are built up one above the other.
In the Eureka district, Nevada,* the system employed for
securing the chambers left by the excavations of the ore-bodies is
FiQ. 373.
by w'iniW square sets, but the mode of joining the pieces of
timber preeente some peculiarities.
Fig. 373 ie a general view of a square set employed at the
Bichmond mine, which explains the manner in which the
tenons and shoulders are cut. This complicated method of
framing is admitted to be expensive, but ita adherents claim that
it possesses great strength. At Eureka mine the joint is simpler.
The Eureka timbering is designed for resisting pressure in all
directious, the Richmond method for offering the greatest resist-
ance in the direction of the caps, the ties being placed parallel
to the walls.
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348 ORE AND STONE-MINING.
The dimenaona of the piecee between the sboulderg are : postfl
6 feet, caps 5 feet, tiee 4 feet, and the timber employed is pine
from the Sierra Nevada, hewn into balks 13 hy iz, 10 by iz, (
10 by 10 incheB,
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SUPPORTING EXCAVATIONS.
249
Square sets are likewise adopted at the Broken Hill mines*
where a wide and soft lode has to be Btoped away (Figs. 374 and
375), and they are being tried in Hodbarrow mine in Cumberland.
The joint used at Brok^ Hi II t is represented in plan by Fig, 3 7 6,in
whidi A A ore the caps, B B the strute, and C the tenon 4 inches
FiQ. 276.
MWWV
FlO. 277.
H
'.vvMiV^N
square on the end of the ufnigbt poet or leg. Fig. 377 explains
the manner of packing the hanging wall wi^ tim^r, so that the
load may be distributed evenly upon the supporting framework.
It also shows how a weak spot
at A is further secured by
horizontal stays.
When additional strength is
required, a lining A (Fig. 378),
or on angle-atay, B, is put in ;
and should these precautions
appear insufficient to prevent
a movement of the ground, the
framework may be reinforced
in rarious ways, as illuatrated
byC, D, Band F (Fig. 378);
F is a solid lo-inch wall of
timber.
HASONBY. — Masonry has long been used for supporting
the roof and sides of mining excavations. The materials necessary
are stone, ordinary bricks or slag-bricks, and they may be built
• Vktoria, Annnal Report of the SeerttaTy of Mina for the Ytar 18S9,
t Heathcole, op. cU.
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250 ORB ASH STONE-MINING.
up alone {dry walling), or with the aid of mortar or hydraulic
cement. Concrete, a mixture of hydraulic cement and email
Jtali.tfrUt
stones, is occasionally employed, and probably could be more so
with advantage.
Once more I will take the three cases of a level, a shaft, and a
working plaoe.
IievelB. — In levels dry walling and timber are sometimes
Fio. aSo.
Jinn 1 1 j J j
combined. Thus, after the excavation of a wide lode, the
rubbish is piled up on the sides, walls are built up of the large
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SUPPOKTING EXCAVATIONS. 251
stones, and caps of timber are laid across, which support the
" deads " when the higher portions of the lode are taken away.
Fig. 279 represents alevel in an iron mine in the Forest of Dean,
where sandstone is available. The pieces are hewn and trimmed
roughly, and a aemi-drcnlar arch is made to rest upon walls at
each side.
Fig. zSoisalevel in one of theminesat Clausthal in the Hartz ;
the sides are constructed of stag-bricks, and at the bottom of the
tunnel there is a channel, made of concrete, for carrying water and
preventing its percolation into lower workings, which would other-
wise necessitate unprofitable pumping.
If both sides (loo^) of avein(ng. 281) are firm, an arch affords
ample protection when the ore has been removed, and provides a
resting place for the rubbish (deads, attk Com.)
A vein is very often a fault, and soft beds may be found
opposite a hard wall of solid rock. In this case the arch is made
to reach from the roof to the fioor (Fig. 282).
One of the main crosscuts at Mansfeld * was lined with concrete
for a length of 1000 m. (g mile) ; 12 metres (40 feet) a day were
put in, and for this purpose 50 metres (164 feet) of centering
were required. The laths were covered with thin sheet-iron, so
as to prevent the concrete from sticking. The concrete was made
of Pcntland cement, broken stone, and gravel, in the proportion of
1 to 7, vh., I part of cement, 2 J of broken atone, and 4 J of gravel.
Up to a height of 16 inches (.40 cm.) from the ground, the layer of
concrete was made thick enough to join on to the sides of the
level, in order to assure a firm foundation. Above that height it
was made only 6 inches thick, the sides of the level having been
previously built up with dry walling.
The centering could be removed at the end of three days, but it
was usually kept in four or five. It was found that five men could
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25a ORE AND STONE-MINING.
pnt in 6 m. (so feet) of concrete liniDg in a shift of twelve lunm.
The cost per running metre waa 31 markB 70 pf. {£1 8«. ^d. per
yard).
Shafta. — Like levels, shafts are lined with maeonry, brick-
work, or concrete, and these have the advantage of being far
more permanent than timber, and of requiring fewer repairs.
When due weight is given to the fact that the shafts are usually
the main thoroughfares of a mine, the necessity of having a lasting
lining becomes very evident.
This kind of shaft-lining is especially desirable in loose ground
near the surface, because if the working is discontinued tem-
porarily, the shaft still remains secure and available for use at any
future time ; whereas if timber is put in, it soon decays, the top of
the shaft collapses, and much expense is incurred in the process
of reopening it.
Another immense advantage of a shaft without timber is its
immunity from fire.
The section of walled shafta is generally circular, as affording
the beet resistance to pressure. Elliptical walling is also met with,
and sometimes the two long sides are made
Fis. 283. with a flat curve, and the two ends with a
curve of much shorter radius. The wall-
ing may be dry or with mortar, according
to circumstances. The maaonry lining is
put in either in one length, or in successive
rings or sections in descending order, and
this is the usual plan.
The shaft is sunk to a certain depth
with a temporary lining of timber, and
when firm ground has been reached, a bed
is cut out on which is placed a crib or
curb, A B, Fig. 283,* consisting of seg-
ments of timber forming a ring. This
serves as a foundation for the brickwork,
which is built up to the surface ; the tem-
porary timbering is sometimes left in and
s removed as the work p
and any vacant apace is filled up with earth
or concrete. Sinking is then resumed, and of a smaller diameter for
a certain distance, so as to leave a bracket or ledge to support the
curb. On arriving, after a certain depth of sinking, at another firm
bed, a second curb, 0 D, is put in, and a second ring of brickwork
built up. When the intervening ledge of rock is reached, it is
carefully removed in small sections, and the brickwork brought
up to the first curb. This process is repeated until the shaft is
completed, or reaches rock in which no masonry is requisite. If,
* J. Callou, LtetUTet on Mining, vol. i. atlas, plate zzvUi.
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SUPPORTING EXCAVATIONS. 253
owing to the nature of the ground, it is impossible at first to find
firm seats for the curbti, it becomes necessary to hang them by iron
bolto from a strong bearing frame at the surface, or to support
them on iron bars fixed in the sides.
Fig. 284 shows a concrete lining put in at the top of the main
shaft at Foxdale mine, in the Isle of Man. The shaft is rect-
angular, 13 feet 6 inches by 10 feet 6 inches. The concrete serres
not only to support the sides in the loose, weak ground near the
?io. 2S4.
top, but also to keep outmucbof the surface water. The concrete
was made of 4 parts by volume of stones ai^ inches to 3 inches
across, 2 parts of sharp sand and i of Portland cement, and the
total oost for materials and labour was i^a. 6d. per cubic yard.
Some shafts in Germany hare lately been lined with concrete
blocks shaped so as to fit the curvature of the sides.* Each block
is fluted at the top and at the ends, whilst the bottom has a bead-
ing, which lies in the channel of the block below it. As the
blocks may weigh as much as one-third of a ton each, it is con-
venient to have some easy means of handUng them. A vertical
hole is therefore left in each block which receives a ring bolt,
fixed by a cotter inserted through a horizontal bole. The block
can then be easily slung to a rope and lowered into position, and
on knocking out the cotter the bolt can be withdrawn. The
spaces between the blocks, and also the bolt-holes, are filled with
cement ; the shaft thus receives what is practically a solid lining
of concrete, which, besides supporting the ground, keeps back
water and acts the part of tubbing. As pointed out by Mr.
■ ZciUchr.f. S..H.- u. S.-WtKn, vol. i
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254 OEE AND STONE-MINING.
Brougb,* a lining of this kind has the advantage over cast-iron
and timber of not corroding or decaying, beaidee which its strength
increaseR with age, and any expansion or contraction from changes
of temperature are inappreciable. Finally, it is far cheaper than
a lining of brickwork or iron.
The Monier syetein consiste in strengthening the concrete by a
coarse net-work or skeleton of iron wire embedded in it. Re-
inforced in ttus way, the fabric has gre&ter tensile strength.
Working FIbobb. — In temporary excavations, like working
placee, rough pillars, built up of lumps of waste stone or of the
Fio, 185.
useful mineral itself, will take the place of timber in supporting
the roof, or may be used as an adjunct to it, as is the case in
Fig, 285, borrowed from Mr. Sawyer.t
The timber at the top serves to make the preesiu* come
gradually upon the stone. The post is eventually drawn out and
the stone recovered.
Walls are also built up with waste stone enclosing spaces which
are filled up with any avaUable rubbish ; and in some instances
excavations are entirely packed with rubbish after the removal of
the useful mineral.
It is only in exceptional cases that it is possible to incur the
expense of building pillars with cement or mortar to support
the roof and sides of working places; but masonry or concrete
* " Notes on the Use of Cement in Shaft-SlnkiQr,'' iVoc N. E. Imt.
M. E., 1803.
+ Op. al.. Fig. 4.
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SUPPORTING EXCAVATIONS.
2SS
arches may be constructed for oartTing the mbbiafa used for filling
the vacant places left by worfadngs upon mitieral veins.
KBTAIiLIC SUPFOBTS. — There are various ways of using
iron and steel as supports for levels, shafts and working places.
IiOTels. — In one part of the Halkyn Drainage tunnel, Flint-
shire, a combination of cast-iron and wrought-iron has been em-
ployed. Mtiab of the level is in bard, solid limestone, and requires
no lining of any kind ; but where small beds of shale were inter-
mixed with the harder rock, timber supports were put in. As the
timber originally used was showing signs of decay, it was decided
in iS$7 to replace it by a more lasting material — iron.
The nature of the Halkyn supports will be easily understood
by IHg. 386. Thereare two TcrticttI props or legs, which are hollow
cylindere of cast-iron, 6 feet 6 inches long, 5 inches in diameter
extemaJly, and 4 inches internally, with a flange 8 inches in
diameter at the top, and 9 inches in diameter at the bottom.
A chnir, shown in section by Fig. 287, drops into the top of the
iron column, and receives a reversed iron rail, 7 feet long, weigh-
ing 117 lb. (50 lb. to the yard), the precise shape of which is
shown on a larger scale by Fig. z88. The iron frames are placed
about 3 feet apart, planks or rails are laid from one to the other,
and the space between them and the roof tightly packed with
stones. A dry stone wall is built up on each side, with an occar
sional plank or rail to make it firmer. I^g. 386 also shows a timber
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256 ORE AND STONE-MINING.
" spreftder" above the water level, carrying longitndiual deepen
with bridge rails forming a waggon-way with a 26-inch gauge.
This method of support is designed for a case where the roof is
weak, and where no great pressure is expected from the sidee. It
would evideDtly be nnsnitAble for the Cornish County adit in
Qwennap, because the water would speedily eat away the iron.
In the Halkyn adit, however, no corrosion need be feared ; for
iron rails which were laid near the mouth of the tunnel veiy many
yeais ago have not been injured by the water. Its cheapness, as
compared with the cost of the walling, was the reason why iron
was adopted in Flintshire. It was estimated that to secure this
part of the adit with the best Buckley brick and hydraulic lime,
would cost over ^4 per yard, whereas the present method has cost
only j£2 4«. per lineal yard of tunnel. It cannot be denied that
i, brick lining would be more permaneat, as the planks in the roof
of the level will have to be replaced from time to time ; but the
cost of repairs is likely to be slight. In more recent work iron
railB and old fire-bare are used instead of wooden lagging.
Steel beams have been used with success for some years at the
Niinneiy Colliery, Sheffield, in the place of timber. They are of
I-section, 4 inches wide, 5 inches deep, with the web |^ inch thick
(Fig. 2S9), and they are considered by Kr. Bainbridge, the manag-
ing director of the colhery, to be of tbe same strength as 12-indi
Norway balk. The beams are supplied in lengths of 6, 7, 8, 9,
and 10 feet, so as to suit drivages of various widths. There are
two ways of using them — (i) as "bars," or caps, resting upon the
timber legs; (2) as legs and cape.
Fig. 290 shows the former method — a horizontal cap, 10 feet
long, reets upon two legs of round Norway timber, 8 to I o inches in
diameter, and a lug or band of wrought iron, t|^ inch by J inch,
shrunk on, preventu the leg from coming in sideways. The
frames or sets are generally placed 3 feet apart, and old timber
laid aci^osB from cap to cap forms the so-called lofiiTig supporting
tbe roof.
The steel beams are tarred over with unboiled gas tar, and
some have been in use several years without showing any signs of
detenoration,whereas tbe averagelife of English larch or Norway
timber, at this colliery, is only two years.
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STJPPOBTING EXCAVATIONS.
257
The beams «*t about £$ i ot. per ton, deliverod at the colliery ;
in other words, a i o-f oot beam costs Ss. A beam of Norway timber
10 foet by 12 inches by 12 inches would contain 10 cubic feet,
and at 8Jd. per cubic foot, would cost ye, id. The difference in
original cost is therefore not very great.
Tia. ago-
/ne/iV >i ra — } — S — J '^V'-t — i — 7 — i — t-nhFM
The advantage of the steel over timber beams are numerous :
1. Greater durability, which means a great reduction in the
cost of repairs.
2. Feasibility of using the beams elsewhere when taken out.
If bent slightly, they can be reversed ; if badly knocked about,
th^ can be sent to the steel works and worked up again. In any
case, they are of some valne.
3. Lightness and handiness. A lo-feet steel beam weighs 166
lbs. ; a 10-feet beam, 12 ioches square, of Norway timber, weighs
3 cwt. The steel beams are not only lighter, but also less bulky,
and consequently more easily handled. Therefore men can do
more work in a given time.
4. Increased space for ventilation. The free spaoe in a level
will be from 5 to 7 inches higher with steel than with timber in
lining an excavation of a given sise. Six inches added to a height
of 6 feet means an increase of i-i2tb, or 8| per cent., in the area
of the airway.
5. Less deterioration of the air of the mine by decaying timber.
6. No danger from fire.
When girders are used as le^ as well b£ caps (Fig. 391), a plate
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2S8 ORE AND STONE-MINING.
of rolled steel, of the shape shown in Figs. 292 and 393, is placed
at each eztremitj of the 1^. The plate is ^ inch thick, 6g inches
Fio 394.
\<mg, by 6 inches wide, with a slot ^ inch wide and 3^ inches long.
The web of the leg posses into this slot and is thus prevented from
slipping sideways, while the tumed-up rim prevents slipping out-
ward or inwards.
Lugs of wrought iron are shrunk on to the cap as in the
previous case.
In makiDg the comparison of cuet, it is necessary to reooUect
that I have chosen a case extremely favourable to steel, because
the beams are made at Sheffield, aod any waste material can he
worked up again on the spot with-
out having to pay a heavy cost of
carriage back to tJie steelwoi^.
One kind of joint used in Bel-
gium * for I-iron is a flanged
bonnet of cast-iron, which receives
the top of the leg and ooe end c^
the cap. A wooden wedge is placed
in the bonnet under the cap, so as
to give a certain amount of elas-
ticity to the frame.
In doing work with a new ma-
terial, a servile imitation of the old
forms is often remarked. The fact
of timber being most readily obtainable in straight pieces naturally
led to the adoption of rectangular, trapeiioidal or polygonal forms
for supporting linings ; but there is no necessity with iron or steel
for copying the shapes which are most suitable with wood. This
was recognised hy the Germans in the early days of iron supports.
AmethiSinnse in the Hartzin 1872 consistedio bending an iron
■ Hiibets, "Le materiel at lea procM^ de 1'Bzploltatiou des Ulnee,"
ExtToiU da Eapporti dv. Jvry International det Bieomptiutt dt VExpMitiou
Unioeri^ iFAmtri, 1SS5. Paris and LI^ 1887, p. 61.
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SUPPORTING EXCAVATIONS.
2S9
Tall aa showa by Fig. 194, and making ic support other rails laid
longitudinally, againat which flattish stoiiee were placed ; th«
vacant place hetween these and the rook whs filled with rabbish.
The ends of the lails were footed in holes out in Urge stanee.
Fig. 295.
Some neat and effective forms of steel supports are made in
Franoe, where more attention has been paid to the subject than
in this couDtiy.
Three kinds made d I-steel by the " Sooi^t^ anonyme des
Fia. 396.
Hants-Fooraeaux, Forges et Ad^riea de Denain et d'Anzin," will
rreas
Pig. i
serve as good ezamplea of steel supporte for levels.
"' ' a slightly bent bar, the ends of whii
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26o ORE AND STONE-MINING.
rest upon d^ walls at the aidee of a level. It, therefore, takes
the place of an arch. Fig. 396 repreeeDta a favourite form of
Umtig for levels ; it is composed of tiro
Via. 397- eide-pieces suitably bent at the top, and
united by a couple of fish-plates (Fig.
397) and four bolts; in some cases a
cant-iron sleeve is used instead of the
fish-platea. When the floor is soft and
liable to "creep," the frame may be-
made of three pieces (Fig. 298).
8ome mines utilise old rails, weigh-
ing 36 to 40 lbs. per yard (18 to 20 kit.
Cr metre) for frames. The mils are
nt into semicircles, and two of theae
are united by bleevee of riveted sheet-
iron, in which they are kept tight by
wooden wedges. Elliptical frames are
used in the Freiberg district, made of
two pieces of rail held together by a
couple of fish-plates at the top and bottom.
Fig. 298.
■CALt or FEC.T
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SUPPORTING EXCAVATIONS. 361
The framee made by the " Compagme dee Fonderies et Forges
de I'Honne " (Loire) are almost invariably composed of two semi-
«irclee of mild steel. Two kinds of sections are employed —
FiO. 300.
namely, channel Bteel and bulb tee steel. Barsof channel steel, 70
mm. X 40 mm., weighing 16 lbs. to the yard, are sawn into proper
lengths on leaving the rolls, and while still
hot are bent into semicirclee. The ends
are carefully planed square, so that the top
eemidrele may rest accurately upon the
lower one (Fig. 299). They are joined by
sleeves made of sbeet-steel, fixed by a couple
of small iron wedges (Fig. 300). It is
claimed by the Honoe Company toat these
frames never give at the joint.
Steel of bulb tee section, weighing 36 lbs. per yai-d, is employed
for beavier ground (Fig. 301). The sleeves are made of riveted
eheet-steel, and are fixed by two wooden wedges, one on each side
of tbe web (Fig. 302). Bars of U-steel of a hollow semicircular
section are used as the lagging ; the steel is ^ inch thick and about
I J inch in diameter, weighing scarcely 2 lbs. per yard (r kilo, per
metre), and it is usually cut in lengths just sufficient to go from
one frame to the next. Small ba^ of steel of square sectaon
are employed for the same purpose.
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263 ORE AND STONE-MINING.
Iron and eteel ma,j be used with advantage instead of timber
for the otmstruction of supporting platformB (ttuBt) in rein-
mining. At Freiberg* fnll-eized rails are employed as croat-
beams (riuB-pieeet) ; they are covered with moall mine rails,
Pio, 301.
and theee with flat stones. Where the pressure is not very
great, wire rope is used for the covering. The rope is cut into
pieces about x metres long, and the ends are
Fio. 303. welded up and bent into hooks. These pieces
are laid across the iron stall -pieces and
covered with stones and rubbish.
In places where the two walls of a lode are
likely to come together a little after a time, the
Btull-pieces are cut about i or i^ inch shorter
than required, and a. wooden wedge is put in at
each end. The pressure of the ground squeezes
up the wedges gradually, and finally the rock
Twce comes against the iron. The rails used as stull-
pieces are often slightly arched so as better to
support the weight of the rubbish, and the flange of the rail is
placed underneath, as ite long straight edge gives a better hold in
the rock than its head. The rails are not cut across at right angles
to their length, but are made somewhat longer above than below,
* Frtibtrgt Berg- and HOttetuneien, Freiberg !, S., 189J, p. tj6.
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SUPPORTING EXCAVATIONS. 263
in order that they may not drop through if bduU pieces of rock
brtnk off under them. In addition to all sorts of small nils,
old fire-bars and old boiler-plates are occasioiially utilised for
" lagging."
A neir departure in driving tunnels in soft ground is furnished
by the Oreathead* shield, by the aid of which two long parallel
tunnels have been driven through clay and gravel, in London,
for passenger traffic by an electric railway. As cases may arise
in mines where this method would be available, it is desirable to
explain briefly the mode of working adopted, and to indicate the
sources where full details will be found. The tunnels of the City
and South London BaiJway may meet easily be described as long
tubes of cast iron, built up ring after ring as the excavation pro-
gressed. The rings are i foot 7 inches long, made in seven seg-
ments bolted together by f-inch bolts passing through the internal
flanges. They therefore closely resemble the watertight lining of
shafte knownas " tubbing," to which reference will be made later.
The ground in the centre part of the end of the tunnel was dug
out, and a cylindrical Bbield was forced forward by hydraulic
jacks. The E^eld had a cutting edge and penetrated into the
day under the pressure. The clay was removed as the shield
went forward, and at last, when ihe advance amounted to 20
inches, a new ring was formed by bolting together the segments,
which then exactly fitted the inside of the ^eld. The progress
of the shield left an annular empty
space i^ inches deep between the ?io. 303.
last ring and the surrounding clay, ^a— i—
equal to the thickness of theshield.
This was filled by injecting Lias
lime grout through a bole in each
s^ment, and so encasing the tunnel .
in concrete. The average progress I
per day was 13 feet 6 inches.
When the tunnel came to water-
bearing gravel aod sand, it was
necessary to have an air-lock and
keep the water back by compretsed
air. In order to prevent the escape
of air into the porous gravel, the
face was cut away in sections, and as each pcvtiim was exposed, a
jet of grout was played upon it to dose the interstices.
Shaft Linings of Iron. — Fig. 303 shows a method of temporary
supportr for sinking little shafts 30 or 40 feet deep. Iron rings,
4 feet 6 inches to 8 feet in diameter are employed to keep lining
planks in poeitioD. The rings are made in two or three segments,
bolted tfwether inside. The iron used is from ji to z^ inches
wide by ^ inch thick.
• £ngiitetring,yoh L, 1890^ p. 551.
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a64 ORE AND STONE-MINING.
Fia. 304.
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SUPPORTING EXCAVATIONS. 265
The rings may be hung one from the other by iron hooka, and
cbanuel iron may take uie plaoe of the flat iron in the circles
around the shaft.
Steel and iron rings are also used in the caee of permanent
supporte for shafts. The accompanying figure (304) shows the
lining of a shaft at Boryalaw, adopted by Herr Flatz, the
director of the ozokerite mines be-
longing to the "Oompagnie C»m- ^o. 306.
mercisle Frwujaise." The shaft
is kept open in very heavy ground
by rings of channel iron placed
1 metre apart from centre to cen-
tre. Each ring is made in two
halves and these are connected by
two special castings, with holes
for bolts ; they act the part of fish-
plates, two bolts being on one side
-of the joint, and two on the other.
Around the rings come oak planks,
2 inches thick, and there are four
distance pieces (sluddUi or posts)
between every two rings. At
intervals of 3 or 3 metres, two
oak bearers are placed across the
shaft, which serve to take up the
weight of the rings if necessary,
though, as a rule, the pressure of
the ground holds the rings very
firmly. The bearers are also »ej.i.g of iwcHcm
utilised for carrying the guides " ■•"• * * r *
or conductors for the cage. acAn o> mi.i.iMiTmm
Fig. 305 represents a ring simi- •.•••.•■•-»..»
lar to those used at Soryslaw,
made by the Witkowitz Ironworks for a shaft 8 feet 6 inches in
diameter, and Fig. 306 gives the details of the connecting piece
and bolts.
Working Places. — We may start with simple cast-iron props
used instead of timber in places where they can be withdrawn.
They are rather heavy, but they will serve over and over again.
At some collieries a large number of these props, from 3 feet
6 inches to 5 feet 6 inches long, are employed, and they appear to
give satifif action. Naturally they have to be made of the same
height as the particular seam which is worked, but any minor
irregularities in the roof are suited by the thickness of the lid, or
by making the lid of two pieces of board. They are set with the
small end downwards. Cast-iron props are not suited for resisting
cross pressures, and they are liable to break occasionally when
they happen to fall.
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a66 ORE AUD STONE-MINING.
Howell's prop is a hollow lap-welded steel tube or pipe,
4 inches in diameter outside, witJi the ends expanded till they
are slightly conica], in order that the top may receive a
wooden plug which projeote about j inch above the steel Theee
props are used alone in workiiig places, or in conjunction with
bars of I-steel, to support the roadways. The foot of the prop
in this case is set out about 6 inches in the bottom so as to pre-
vent it from coming in sideways. The object of the plug is to
obtain a certain amount of elasticity.
A third kind of prop is made of I-iron or steel, either cut off
square or with the web cut out for a few inches, and the two
flanges turned over so as to make ends with a larger bearing
Fio. 307. Fia. 308.
surface {Fig. 307). The holes a a enable the props to be with-
drawn by a hook.
WATERTIGHT LINITTGW FOB SHAFTS.— We must
now turn to the special case of shafts which have to pass
through watery strata. Here it is often advisable to put in a
watertight lining, in otder to prevent the inflow of water, and so
save the expense of pumping it out day after day, and year after
The lining may be made of wood, brick, and hydraulic lime or
cement, or, lastly, iron.
There are two kinds of wooden tubbing: (i) Flank tubbing,
whence this kind of lining originally received its name ; and
(z) sohd timber tubbing. Flank tubbing is made of boards from
2 to 3 inches thick, arranged vertically round the shaft and cut
with a bevel like the staves of a cylindrical barrel. The planks
are nailed on to rings of wood placed at suitable intervals.
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STJPPOBTING EXCAVATIONS. 267
Solid wooden tubbing (Fig. 308) consiste of carefully shaped
blocks of oak or elm, with thin sheets of deal placed between the
joints. The joints are wedged up as tightly as possible, and a
lining of this kind can be made so as to resist a very considerable
pressure of water, even 300 to 300 lbs. per square inch.*
The method known as " coffering " consists in lining the shaft
with a wall made of brick and cement, or brick and hydraiilio
lime, and backing this up with puddled clay. It is specially used
for keeping back the surface-water.
Full deteila concerning this method will be found in the papert
quoted below, and my description may be very brief. In one
particular instance the shaft received first of all a temporary
lining of 9-inch brickwork put in dry during the course of sinking,
the successive sections being held up by wooden cribs or curbs—
that is to say, rings of oak placed 4 to 5 feet apart. Each ring
was hung from the one above it by vertical pieces of 1 ^-inch plank
Fia. 309.
Sfoked on to both rings. When firm ground below the watery
strata had been reached, a level bed was cut for putting in the
wedging-crib — a ring made of segments of cast-iron, either like
A or B in section (Fig. 309). By means of wedges driven in
behind, it was made perfectly tight and xtanch. Three courses
of brickwork made with Roman cement were built up on the crib
and the wedges behind it; they formed the foundation for the
"coffering " proper, which consisted of three rings of brickwork in
hydraulic mortar E E (Fig. 310), separated by the two rings of
hydraulic mortar F F, and the puddled clay D. B repreeente the
original lining of nine inches of dry brickwork put in against the
watery strata. As water running down the sides of the shaft
would render it impossible to carry out this kind of work satis-
factorily, means had to be adopted for getting rid of it. A
garland or circular launder was fixed around the shaft so as to
intercept it before it could interfere with the work of coffer-
ing, whilst water coming in behind the coSeriog was drawn off
during the progress of the work by placing a vertical launder
against the preliminary lining of bricks. This launder was pierced
with holes every three inches, and communicated at the bottom
• B. Bainbridge, " On the KiDd-Cbaadron System of Binkiug Shafts
thtoDgh Water-beaiiDg Strata," Proc. Intt. C.B., vol. xxxlv., 1871-1872,
Flal« iz.
t N. B. GriiBth, " On the Coffering of Bbafls to keep back Water,"
TVant. N. Eng. liM. Mia. Mtdi. Bag., vol. iivi., 1876-77, p. 3.
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268 ORE AND STONE-MINING.
with a block of wood which htui a 3-inch hole bored through it,
optaiDg into the shaft just above the wedging-orib. As it became
Scale of Feet
gradually buried by putting in the clay D, the holes were plugged
up, and finally the launder was filled with pieces of stone, and
cement was run in.
The walling was done with hydraulic mortar, made of one of blue
lias lirae to two of sand, and the middle course was grouted in,
either with a similar mixture or with pure Iloman cement.
The advantage of cofiering over the ordinary metallic lining
known as tubbing is its cheapness. Mr. Gri£ith puts the cost of
coffering a shaft ne sank at ;^io 5a. per yard, and he estimates
that a suitable cast-iron tubbing would have cost ^23 per yard.
The pit was zo feet in diameter clear within the original lining of
dry bricks, and as the coffering was z feet thick, the final diameter
of the pit was reduced to 16 feet.
Where the ground is soft, a cast-iron lining may be made to
sink down by its own weight and by pressure applied to it. This
process was adopted at Restronguet Creek,*a branch of Falmouth
Harbour, in order to work a bed of stream-tin. The creek had
10 or 12 feet of water at high tide, and was nothing but a mud-
bank at low tide. A staging was oonstnioted upon piles in the
creek, in order to have room for working, and a first cylinder, with
n BestroDgaet Creek,
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SUPPORTING EXCAVATIONS.
369
a cutting edge, was placed upon the mud, two more cylinders
were then bolted on, &nd their weight caused the whole to sink
down. The cylinders, made of cast-iron, were 6 feet high by 6 feet
in diameter and i^ inch thick, and they were joined by internal
flanges faced in the lathe. Each ring weighed about 2^ tons,
and was lowered by a crane through an opening in the stage,
between guides in order to keep it vertioil. When the firat
three rings had ceased to sink, the mud inside was cleared out^
and further cylinders were added and forced down by pressure
from the chain of a crab-winch. Afterwards an ingenious method
of taking advantage of the rise and fall of the tide was resorted to.
A huge girder was laid across the top ring, and a barge laden
with stone was attached to each end. The fastening was made
complete at high water, and when the tide fell the full weight of
the barges came npon the girder, and so upon the shaft. The
cylinder was thus sunk to the full depth without difficulty.
During the sinking the core was always cleared out a little below
the bottom of the cylinder before the barges were attached, and,
if left for a day, the mud was found to swell up 3 or 4 feet into it.
A total weight of about 250 tons was required to sink the cylinder
JElerO'ti'aTt-
cj: JBa-ok.
r J
II II J
^ 1
DUL_
r J
II \\~\
^ 1
a« it neared the bed of tin ore. Altogether, thirteen of the 6-f6et
rings were sunk, making a total depth of 78 feet.
^e ordinary method of tubbing is that in which the rings are
made up of segments, and as a rule the cylinder of cast-iron plates
is built up within some temporary lining ; this is carried down
until it reaches some solid and impervious stratum below the
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a70
ORE iND STOKE-MININQ.
water-beaiing measures, fit to serve as a foundation. When aoch
a str&tum has been found, the sinking is continued for a few feet,
and a bed is cut out very carefully, and trimmed perfectly even and
horizontal, bo as to receive the first crib or curb similar to those
just described in the case of coffering. The curb is a hollow ring
of cafit-iron made in segments about 4 feet long. Strips of deal
about ^-inch thick are placed between every joint, and the seg-
ments are brought tightly together by wedging up the space be-
tween the outside of the curb and the rock. The joints are finally
rendered perfectly stanch by driving in wedges into the deal strips,
A second curb is laid upon the first, with intervening stripe of deal,
and the wedging process repeated ; sometimea a third curb comes
upon the second. The top curb is the foundation for the tubbing
proper, which is built up segment after segment. The segments
are usually i to 3 feet high and 4 feet long (Fig, 311); their thick-
ness depends upon the pressure of water they have to withstand
and varies between J inch and 3^ inches. They are smooth ioude,
but are strengthened with flaiiges and ribs on the side turned
towards the ground.
The segments are kept in place by wedging them against the
sides of t£e pit, and fillmg up the interspace with earth or con-
crete ; thorough stanchnass is secured by interposing a half-inch
strip of deal or pitch pine at
Fios. 31a & 313. every joint, and finally driving
in wedges when all the tubbing
is fixed. Water coming in from
the surrounding strata is al-
lowed to escape through the
central hole of each s^ment.
A cast-iron lining cylinder
(Figs. 312 and 313) is thus
_y built up inside the shaft until
an impervious stratum above
the water-bearing ground is
reached; another wedging curi>
then completes the tubbing.
The joints are wedged up as
tightly as poHsible, and finally
plugs are driven into the cen-
tral holes of the segments. If
the work has been properly performed, the lining will be water-
tight. The tubbing is sometimes put in by a succession of com-
paratively short sections, each restingupon its own wedging curb,
and shutting ofi* a portion of the water-bearing beds. If this
method is pursued, each separate section is continued upwards to
the next wedging curb above, resting upon a bracket of rock ;
this is cut away very carefully in small sections, and the last
ring of segments made to join it exactly. When the amount of
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SUPPORTING EXCAVATIONS. 271
'water is not exododve, it is usual to sink through the vhole of
these strata before setting a wedging curb and fixing the seg-
ments.*
In a few cases no temporary lining is used, and the segments
are at once inserted in descending order, eaeh ring hanging from
the one above it. After serend rings hare been so fixed, a
beariiig-ring is put in and the wedging of the joints proceeded
with. This process is repeated until strata are reached which
require no such lining.
BFSOIAL PBOCBSSXS. — The amount of water met with
has been sometimes bo great as te render HinTting by the ordinary
methods quite impossible, on account of there not being room
enough in the sbafto for fixing pumps sufficiently large to cope
with the enormous feeders of water, and even where pumping is
possible the expense may render it out of the question. A. few
figures quoted by Kr. Bainbridget will give some idea of the
enormoos cost due to water-bearing beds. In Germany the sink-
ing of a pit, only 239 feet deep, ooet ;£96,ooa, and occupied 40
months, although the quantity of water pumped was only 606
gallons per minute. For another pit the corresponding figures
were 570 feet, ;£i40|OOo, 91 months, 3200 gtdlons, T^ing
eleven cases, it appears tbat the ooet varied between ^^36 and
^145 per foot of sinking, and that the average rate at which the
sinking progressed variad from 3-9 to 17-2 feet per month.
For dealing with cases of this kind, there are three principal
metiiods of sinking which deserve special mention: (1) Kind-
Ghaudron or boring method; (2) Triger or compressed air
method; (3) Foetsch or freezing method.
Boring Uethod. — Kind's process as improved by Chaudron
consiste briefly in boring out the ehaft by m.eans similar to those
employed for searching for mineral, and then lowering into the
pit BO formed a watertight lining of cast-iron, which can be made
stanch at the bottom even under water. The great advantage of
this process is that there is no pumping at all until the operations
of sinking and lining are complete; andtii6n,indeed, itisonly the
contente of the shaft itself that have to be drawn up.
The various stages of the process are as follows : —
(i) Alternately boring asmall pit in advance, and enlarging it
by a bigger tool to the full size of the shaft.
ia) Preparing a seat for the moes-boz.
3) Lowering the water-tight lining (tabbing) with its moss-box
at the bottom.
(4) Putting in the outside lining of concrete.
(5) Pumping out.
^is process bss been frequently described at great length, and
pOTSons who require more details than can be given in a general
* Bl^bridge, Undem. t lUdem,
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Pl8. 314.
272 ORE AND STONE-MINING.
text-book will do veil to coiiBuIt the origiiial papers mentioned
Tte preliminarf pit is bored 4 or 5 feet in diameter, a^d is
alwaya kept well in advance of the full-sized sliaft, genendly from
30 to lOD feet.
The tool used is a oompoeite borer with fourteen cutting obisele a
fixed in round sockets (Fig. 314). Above the chisels there is
the croBs-piece 6, with two cutters, which serve
to trim off any alight irregularities; at the same
•^ time it acts as a guide, and so tends to ensure the
verticality of the hole. There is also a second
I guide o above it, without teeth. The total weight
_— J M of this tool is from 7 to 8 tons. It is suspended
•*— 1— 1 ' from a series of pitch-pine rods, each 58 to 59 feet
in length. Some used in Belgium were 7I inches
square. Those used at Marsden were only 5 inches
square. At each end of the rod an iiroD fork is
clamped and bolted 00, terminating in a taper male
or female screw. The top rod is connected to a
strong chain hanging from one end of a huge h(m-
zontal wooden b^m. The other end of the beam is
attached by a chain to the piston of a vertical steam
cylinder. When Bteam is admitted on the top of
the piston, the rods and tool are raised, but as soon
as the eugine-mau opens the valve which lets the
steam escape, the rods and tool fall by their own
weight, and the rock is chipped at the bottom of
the hole. Two methods have been employed for
avoiding the injurious vibrations of the rods which
would occur if there were a rigid connection be-
tween them and the tool. One is a sliding joint
similar in principle to that of Oeynhausen ; the other is some
free-falling arrangement, such as the catch actuated by a disc,
which has already been described (Fig. 122).
The rods are turned in the usual way by a tiller, and they can
be lowered, as the hole is deepened, by a screw similar to that used
in small borings.
The mud and fragments produced in boring are cleared out
by a sludger ; that is to say, a hollow sheet-iron cylinder provided
with semicircular flap-valves at the bottom. The sludger is
sometimes worked by the rods and sometimes by a rope, which
* Chandron, " ProcMS Kind. Travauz executes en Belgiqne," ^nnulm
lie* Mints, f< Sirle, tome iTJii, pp. 43J tt $eq, ; Smyth, " On the Sinking of
Fit Shafts by Boring ander Water, as practised by Messrs. Kind Jc Chan-
dron," IVaiit. N. E. Intt. Jti.Bng,, vol. jli., 1871. p. 187 ; Bainbridge, "On
the Kind-Cbaudron System of Sinking Shafts throagh Water^beariag
Strata, without the Aid of Pumping Hacliinery," Proc. Inst. C.E., vol.
- ■■ 1. ''On tt - ■ ■ - ~ -----
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SUPPORTING EXCAVATIONS.
»73
s (Kuled
FIO. 315.
passes over a pnlley at the top of the boring tower, and i
on R drum set in motion by a special steam-engine.
"When a small shaft has been cut out in this way, either for
part or the whole of its depth, the work of enlarging m&y com-
mence. The enlarging tool is a huge composite borer (Fig. 315),
with twenty-eight cutting chisels, weighing 16^ tons; in the
centre it has a projecting loop of iron a, which
fits loosely into the small shaft, and serves as
a guide. The chisels are armnged so as to
make a sloping cut, in order that the sludge
and chips may pass down easily into the inner
pit.
In some cases the ordinary sludger is em-
ployed for clearing out this hole, but atrange-
ments may be made for catching the debris
in a special bucket, which is either placed
at the bottom of the hole, or is hung from a
little ledge cut for the purpose. When it is
supposed that it is full, the boring rods are
lowered and the bottom one screwed on to it.
This operation might appear somewhat diffi'
cult, but by providing the female screw at
the end of the bottom rod with a funnel-
ahaped bonnet, it ia guided into its proper
course over the male screw on the sludger
bucket, and the necessary connection is
easily made.
The shaft is thus sunk to the required
depth, which must previously have been
ascertained by a small borehole. When
therefore it is known that a bed suitable
for a foundation below the water-logged
strata has been reached, a seat is prepared by boring very
carefully with the chisels arranged horiEontally. The seat is
scraped with a special tool, bo as to dear off any stones, and the
tubbing can now be lowered. The scraping daws can also be
used just before the tubbing toaches the bottom, as they will
pass through the central equilibrium pipe which will be de-
scribed immediately. The tubbing is made of rings of cast-iron
joined by bolts through their internal flanges. A thin strip of
sheet lead is put in the joint so as to make it stanch. The flanges
are !all faced in a lathe in order to secure not only a watertight
jointjbut also the perfect verticality of the whole column. At the
venr bottom there are two rings with flanges turned outwards,
and the upper is capable of sliding down over the lower. The
space between the two outer flanges is filled with moss, which is
further kept in place by a net. lastly, just above this moes-box,
as it ia called, a dish-like bottom is bolted on, carrying a central
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a74 OEE AND STONE-MINING.
pipe which can be lengthened aa the tubbing descends. The pipe
ie called the equilibrium tube.
The whole arrangement is best understood from Fig. 316.* B is
the bottom ring carrying the moss outside it; A is the ring which
can slide down over it tdescopically ; O is the close bottom of the
colamn of tubbing, H the equilitnium tube, I the space between
Fies. 316, 317 & 318.
_!_
the tubbing and the sides of the shaft. The column is lowered
into the shaft by meaus of six iron rods, to which lengthening
pieces are added as required. The top part of each suspend-
ing rod is a strong screw, 13 feet long, working in a big
nut cm a frame above the shaft. The screwed rod, attached by
a swivel to the rod below, can be turned round by a little winch.
After a new ring has been put on, men at these six little winches
lower the column slowly; but the whole weight of the column
* DagUsb, op. c
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SUPPORTING EXCAVATIONS. 275
does not come upon the screws. The watertight bottom G causee
the tubbing to displ&oe so much water in the shaft, that the whole
colomn could be made to float if neceBsary. Such buoyancy would
be inconvenieat ; nnd it is desirable that the column should be
made heavy enough to sink down of itself when the screws are
worked. The neceesary excess of weight is obtained by tapping
the equilibrium pipe, and allowing a certain amount of water to
flow into the annular space around it. The column weighted in
this way finally arrivee at the bottom of the pit, and the broad
flange of the ring B rests on D as shown. When the lowering
ia contiuued, the ring A slides down over B, which is stationary,
■and the flange 0 compresses the moss lying in the moss-box,
squeezes it outwards against the sides of the shaft and makes a
watertight joint (Fig- 317).
The next operation is filling up the annular space outside
the tubbing with cement or concrete. The cement used in eer-
-tain cases was a mixture of hydraulic lime with sand and trass.
It is lowered in special boxes so constructed that their contents
■can he discharged when they have reached any required poeilion.
After ample time for hardening has been given, the water is drawn
out of the shaft by a bucket ; the dish-like bottom is now taken
■off, and the joint made by the moss-box can be examined. Even
when this joint seems perfectly good, it is thought desirable by
some to take the additional precaution of putting in a wedging
■curb in the ordinary way a little below the moss-box (Figs. 317
-and 318); a few rings of ordinary segmental tubbing are then
built up in the interval. A careful joint is made, and the shaft
ia looked upon aa permanently secure.
The advantages of the Kind-Chaudron process, which are
«numerated at length in Sir Warington Smyth's paper, may be
briefly summed up as follows : safety, economy and speed.
During the last few years several modifications of the original
Kind-Chaudron process have been introduced with success. At
Gneisenau near Dortmund all tubbing above the level of the
water-bearing measures was discarded. A column of tubbing,
■closed at the top as well as at the bottom, and somewhat louger
than the height of the watery strata, waa lowered into the shaft ;
and in order to overcome its buoyancy a sufficient amount of water
was let into it bytivalve, workedbyarod reaching to the surface.
When the moes-boz had been compressed by the descent of the
•column, oemsnt was lowered into the annular space, along special
guide-ropes extending from the bottom ring but one of the
tubbing to the top of the pit. This plan enabled the boxes to be
sent down and drawn up more speedily than would have been the
case if they had been loose. After allowing sufficient time for the
complete hardening of the cement, the water was drawn out of
the pit, and a regular wedging curh was put in above the column
•of tubbing and its protecting jacket of cement.
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zyfi
ORE AND STONE-MINING.
This method of doing the work saved 190 yarils (174 m.) of
tubbing at the top of the pit, and the gain in money was estimated
at £7500.
At the {present tame the moss-box seems to be losing much of
the prestige which it formerly possessed, and French engineers
are content to rely solely upon careful cementing for a water-tight
joint at the bottom of the tubbing. A shaft was successfully
sunk a few years ago by the " Compagnie de I'Escarpelle " in the
Noilh of France without using either moes-boz, equilibrium
FiQ. 319.
— 1
■ ■■-■- SMcntEs.
--=^ —
*
~
D
^ ft
^=
t
e. .
^^
:
c
" . l«
-=:=
L^
; 1
A, OreflD clajey marl, verj plastic and impermeable {Diivet
verta). B, Small boring, C, First ring of tubbing, with strong
shoe, weighing t2 tons. D, Second ring of tnbbin(c. E, Ring
bolted to a Qange of D. F, False bottom bolted to K. G, Man-
hole cover. H, Concrete. The rings of tabbing are joined to
each other bj sizt; bolts, and the apper and lower SEinges are
strengthened by brackets midway between the holes. These
brackets have been omitted in the figare for the sake of clearness.
tube, or the subsequent wedging curb and false tubbing; and
the Li^vin Company in the same colliery disteict, when sinking
two sbofteia 1891-92, likewise decided to dispense with all the con-
trivances peculiar to the Kind-Chaudron method. The process of
sinking was very much simplified. They bored the shaft in two
operations : a first pit 2 metres (6ft. 6ia.) in diameter was carried
down some ten or twelve metres beyond the actual depth required,
and it was then enlarged by a second tool, 4'9om. wide, to the full
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SUPPORTING EXCAVATIONS. a;;
diameter of about 5m. {i6ft. 5in.). This plan obviated all difficulty
due to a tooth dropping from the large borer ; it had simply to be
scraped into the email shaft and was left at the bottom until the
completion of the tubbing. In the Eind-Chaudron process of
boriug the email and the large shaft alternately, it would have
been necessary to fish up the tool before the smaller shaft could
have been sunk any farther. On reaching the required depth
the teeth of the large borer were fixed so as to cut a horizontal
seat, which was then scraped clean with an S-like tool for
the reception of the tubbing. The bottom ring was made
with a shoe (Fig. 319), and was calculated to leave an annular
apace 14 inches (35 cm.) wide for cement, and the huge column
with its watertight baae was built up and lowered without any
equilibrium tube. It floated like an enoi'mous boat and was
weighted with water so as to sink as required. After it had
been very carefully brought into the centre of the pit, the concrete
was lowered in specially contrived boxes which deposited it
automatically on reaching the bottom. The successful result of
these siukingB has justified the procedure of the Li6viQ engineers ;
they are of opinion that, in any future sinking, time might be
saved by doing the boring in three operations instead of two.
The following facts* relating to one of the pits lately sunk by
the Li^vin Company (No. 4 bU) show the rapidity with which
the work can be canied out. Baring with the small tool began
on the ist of November 1891, and was stopped on the I4tb of
Januanr 1893, when a depth of iii-yim, (122 yards) had been
reached. The large tool was set to work on thei6th of January,
and by the 7th of June following the pit had been bored to the
depth of 100 metres (109 yards). A week was then occupied in
cleaning the bed, taking down the boring plant, and making
preparations for putting in the tubbing. Be^nning on the
14th of June, the lowering of the tubbing was finished on the
29th; it took three days to get the column into position and
make it rest properly upon its seat, and three weeks to put in the
concrete. After spendmg ten days in taking down the boring
shed and plant, the engineers were able to b^n drawing out the
water on the 2nd of August, and they finished on the 7th. The
false bottom wes brought up on the 3th of August, and prepara-
tions were at onoe made for continuing the sinking in the ordinary
way. The sinking was recommenced on the 30th of August.
Compressed Air Method. — Sinking by the tad of compressed
air came into notice after a successful application of this method
by M. Triger in France about half a century ago. In this
method a cylinder of cast-iron, made up by adding ring after ring
■ai the surface, like a column of Chaudron's tubbing, is caused to
fink gradually by the earth in the bottom being worked away ;
* Kindly famished by M. Desailly, the et^neer in cbarge.
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278 ORB AND STOXE-MININO.
and m order to prevent the water in the Burroundiiig beds from
coming in, air under pressure is led into a chamber at the
bottom of the cylinder, which is shut off by a homontal partition
or diaphragm. Above this working chamber there is an "air
lock," that is to say a closed space in the cylinder, with teap
doors above and below. The two doors are never open at the
same time. A man going down to his work passes into the
middle chamber by the trap door, which is then closed ; the lower
trap door is now opened, and the man can descend into the
working chamber. When he goes up, or when the bucket has
to be drawn out, there is always this break of the journey, in
order to prevent the working chamber from communicating
directly with the atmosphere. Sinkings by this process have
been made since Triger'B time in various places, among others at
Bettisfield colliery in North Wales,* though in this case the
arraogemestA were not exactly the same as those originally
employed in France.
There are two great disadvantages coupled with this method:
(i) The impossibility of going to a depth much exceeding lOo
feet, because, speaking generally, a pressure of 45 lbs. per square
inch, or three atmospheres above the normal pressure of the
atmosphere is about as much as men can stand.
(z) The fact that the health of the men has been found to
suffer from such an atmosphere. In all cases it appears advisable
to avoid the sudden changes of pressure, and therefore invariably
to make a little stay in the air-lock before going up or down.
Freeziiig Method. — The solidification of watery strata by cold
may be effected naturally or artificially. In Siberia,t when sink-
ing shallow exploratory pits through watery strata in search of
auriferous alluvia, advantage is taken by prospecting parties of the
severe cold to let Nature form protecting walls of frozen ground.
Iq Western Siberia the process is as follows : Towards the end
of the summer, square pits about 6 or 7 feet on the side are sunk
as deep as possible without peaetrating into the watery beds.
The men then prepare log-huts, as dwellings for the winter, and
lay in good stocks of firewood. After the first frost the snow is
cleared out of the pits, and also from off the ground for a space
several yards in diameter round the tops, in order to let the cold
penetrate more freely. Aa soon as the ground is thoroughly
frozen, the sinking is begun by a kind of fire-setting. Billets of
wood ore laid crosswise on the bottom of the ground and lighted.
The fire thaws the ground for a short distance, and the workmen
have to be careful that the heat does not penetrate too far, and
so let in the water from the unfrozen strata a short distance be-
* LnptoQ, discussion on Mr. Datclish's paper, "On the Sinking of Two
Shafts at Marsdeo," i'roc. Intl. C.E., vol. lui. 1892-93, p. 197, with figure.
+ Helmhacker. " Veber daa in Sibirien iibliohe Abteufen von Schurf-
Bcb&chten in achwimmeuden Gebirge," B. u. h. Z., 1S91, p. 88.
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SUPPORTING EXCAVATIONS. 279
low line i, i, repreeentiag the junction of the frozen with the
unfrozen ground (Fig. 320).
The workmen with pick and shovel remove the softened portion
(a), iind so deepen the shaft bj some 4 to 6 inches. It is then left,
for two or three days to freeze again, when the junction between
frozen and unfrozen ground is carried to 2, 2 ; a second fire
softens the part {b) which is removed, and then another expoeure
to the frost for two or three days makes the ground solid to 3, 3,
when the part (c) can be softened and taken out.
Fio. 3Z0.
A
The alternate processes of freezing and thawing are repeated
every three or four days, and each time the shaft is deepened
from 4 to 8 inches. As the auriferous bed is approached, samples
are washed from time to time to see whether there is any gold,
and when the stratum containing the precious metal is reached
(Fig. 321), all the earth is carefully washed and the amount of
gold noted. Judging by results of similar undertakings in the
district, it is possible to say whether or not it will pay to work
the alluvium. In both figures, A represents the bed rock, B the
stratum of gold-bearing gravel, 0 overlying gravel containing little
or no gold, D timbering at the top. TTie hatching denotes ground
that is frozen. The shafts are sunk to a depth of 16 to z6 feet.
In Eastern Siberia the conditions are more favourable for
this kind of work, as the winter is longer, and therefore the shafts
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28o ORE AND STONE-MINING.
can be sunk deeper. But the principal advantage lies in the fact
tbat much of the ground ie eternally frozen ; here the thawing
can be carried on without any stoppages, and \eee care is neces-
anry, save when the underlying unfroien strata are reached.
Thcee have to be treated by alternate freezing and thawing as in
Western Siberia. Aa a rule, however, the ground is eternally
fn»en for the whole thickness of the alluvium down to the bed
Pio. 321.
A
rock. Exploratory pits are sunk in Eastern Siberia to a depth
of 85 feet (36 m.) by this method.
Shafts are even put down in shallow rivers to see whether their
beds are gold-bearing. In autumn, when the water is shallow, a
set of frames, like shaft frames, 6 or 7 feet square, is lowered till
it touches the bottom, whilst the top is above the level of the
stream. It is filled up with stones, and loose stones are placed
around it. When winter sets in, the river freezes, and the con*
tents of the box gradually become hard. A first layer of stones
is then worked out with the pick, and the frost allowed to pene-
trate downwards. Another layer of stonee is taken out, and
again there is an interval for freezing. By repeating this pro-
cess the contents of the box are removed Uttle by little, and at
last the rivei' bed is reached and allowed to become hard and
solid from the cold, whilst at the same time the water in the
interstices between the outer stones has been congealed, and has
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SUPPORTING EXCAVATIONS. 281
formed strong protdcting walls of icy coaglomerate. Further
smking is now carried on as in Western Siberia.
Id some cases the wooden box ia dispensed with, and when
the river is covered with a thick coat of ice, the prospector cuts
out a space a few inches deep of the size of the shaft. The
removal of a part of the ice at the top allows the cold to be
felt further down, and the ice becomes thicker underneath.
Another slice is taken off the top and again the cold penetratee
further, and in proportion as the top ia removed the bottom re-
caves coat after coat of new ice. By successive thickenings the
ice iinally reaches the river bed, and the prospector can then pro-
ceed by the West Siberian method.
Poetach's artificial freezing process consists in causing a v4ry
cold liquid to circulate in pipes through the ground, and so con-
vert it into a sohd mass, in which an excavation can be made
without timber or other supports. While the ground is kept
frozen some form of watertight lining is put in, suficiently stanch
to keep out the water when the cold-producing appliances are
removed.
Poetsch employs a Oarr£ machine for generating cold. Anhy-
drous ammonia gas is liquefied by compression in suitable pumps,
and the liquid which leaves at a temperature of ioa° F. (38° C.) is
cooled by passing it through pipes surrounded by cold water.
The cold liquid ammonia is then made to flow into a long series
of pipes, placed in a large wooden tank containing a solution of
chloride of calcium. The liquid ammonia expands into gas in
these pipes, and extracts heat from the solution surrounding th6m
to such an extent that the temperature of the contents of the
tank is brought down to 8° org'F. ( - 13° 0.) The ammonia gas
is returned to the compressor to be again liquefied and utilised
for the production of cold.
The refrigerating solution of chloride of calcium is pumped
from the tanks into a main, which leads it to a series of pipes,
placed in boreholes arranged in a circle around the top of the
proposed shaft. The pipes are double, that is to say, there is
an inner small pipe i^ or 2 inches in diameter for the down-
ward journey of the cold solution, and an outer one 4}- to 7
inches in diameter, carefully closed at the bottom, by which the
solution ascends and does its cooling work on the way. When it
reaches the surface it returns to the cooling tank, and is again
refrigerated. The process is, therefore, coutinuous, the ammonia
and the chloride b^g used over and over again. The nature of
the freezing-tube will he evident from Fig. 322 * ; a is the large
ontco' pipe connected to another, m, by the piece, J"; n is a small
* Poetacli, " Uebei die verbesBerte AnsfOhning des Oefrierverfahrens
belm Sobacbtableufeii and Btreckenbetrieb," Der in. aUgenuiiu Btrgmantu-
tag in BaJU [SaaU]. Fatbtrieht uad VerhatuUangtn. Halle, 1S90, p. 1 19.
and Plate z.
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282 ORE AND STONE-MINING.
inner pipe, and the arrows show the course of the solution. The
supply of chloride is taken from a circular pipe at the top, fed
no, 322, no. 323.
DEPOSIT TO
IE WOKKCD
from the main, and in like manner the solution ascendiag the
various pipes is collected by another ring and led back to the
cooler. The particular pipe shown in the figure is destined for
the case of a sinking, in which the upper part, m, is in strata that
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STJPPORTINa EXOAYATIONS. 283
do not need to be frozen. The letter p represente & jacket made
of some bad conductor, to prevent the Etolution from becoming
warmed unnecessarily in ite aecent.
In sinking through ground consisting of watery strata alternat-
ing with dry measures, Poetsch advises the following method
of procedure. A (Fig. 323) represents dry ground through which
the Bhaft has been sunk and timbered in the ordinary way;
B indicates watery beds where tubbing is neceesary. Poetsch puts
in first of all a circle of holes, a a, round the outside of the shaft,
and a smaller circle b b, around the inside. When these latter have
frozen the ground adjacent to them , the still smaller circle of holes
6 6, are bored and fitted with refrigerating tubes ; as soon as
the ground about them has become converted into a solid pro-
tecting wall, the shaft is sunk with a reduced diameter, until the
dry strata, C, are pierced. On reaching ground suitable for the
wedging curb, the tubbing is built up in the ordinary way ; the
parts b b are cut away, and by this time the freezing has become
so complete at a that there is no danger of the walls falling in.
In this process there is a risk of failure, or at all events of
trouble, if there is any escape of the freezing solution from the
pipes, because the ground impregnated with it would be uncon-
gtt^ble. Gohert proposes to overcome this difiiculty, and at the
same time to make the method more economical, by sending
down anhydrous, or all but anhydrous, ammonia, and allowing
it to vaporise in the tubes, instead of circulating a refrigerating
solution. Intense cold is thus produced at the very point where
It is required, and the ground is frozen. The ammonia gas is
drawn out by a pump, and aft«r having been reliquefied by pressure
is used over again. Oobert claims for this process that both the
original outlay for plant, and the subsequent running expenses, are
considerably reduced. He has also been led by his experience to
introduce improvements in the joints of the freezing pipes, with
the object of ensuring absolute freedom from lealuge, and of
making the line of pipes quite flush outside, so as to facilitate their
withdrawal at the end of the sinking.
It has been proposed* to inject powdered cement, by means of
compressed air or steam, into watery strata, and so consolidate
them sufficiently to render the sinking of a shaft a matter of no
great difficulty.
The Haaae Frooe88,f for sinking through quicksands, consists
in forcing down a set of wrought-iron tubes around a circular
or I'ectangular area destined for the shaft. The narrow inter-
spaces between the tubes are closed by angle-iron and T-iron
riveted on longitudinally, which form a joint permitting vertical
motion and stanch enough for the work in question. Water forced
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384 ORE AND STONE-MINING.
down a hollow boring rod in the middle of each tube loosens the
sand and carriee it up to the surface. The tube can then be
driven down by a screw-jack or an faydraullc prees. The tubes
are carefully guided in order to ensure a strictly vertical path ;
and as soon as they have been forced down into bMrd or compara-
tively hard rock, the quicksand can be excavated, for the iron
lining prevents any influx from the outside.
Instead of iron tubee, Haeuser* employs sheets of corrugated
iron, with tongues riveted on so that the bottom of each sheet
ia held by the top of the one below. Like the Haase tubes, the
sheets are forced down with a strong screw-jack. Another plan
adopted iy Haeuser consists in making the protecting shield of
pieoee of Sat iron 6 inches wide; each "lath," if it maybe so
called, is connected to its neighbour by a longitudinal groove
formed by riveting on two strips of iron.
* Herald, " Daa SohBcht-Abteufen im schwimmecden Gebir^ mit Haass'
BcbemundHaeuser'BchemVerfatiren beim Bmankohlenwerk 'Zwenlcau'In
Zwenlcao," Jahrb.f. d. B.- vmd H.- Weten i. R. Sadutn, 1891, p. 27.
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( »85 )
CHAPTER VI.
EXPLOITATION.
r bore-holea. (4) Unde^roaiid
The methods of working mineral deposits may be naturally
arranged into two great classes — viz., open work*, in which the ex-
cavation is open to the sky ; and v.ndergr(ywnd loorka, in which the
miners perform their labour in chambers or passages under a cover
of rock or earth, and in which they usually need artificial light.
But there are in addition two other classes of workings, used in
comparatively exceptional cases, which require a place in any com-
plete classification. Oold-bearing gravel and phosphates are occa-
sionally dredged up from river-bottouiH ; and liquid, gaseous, or
soluble minerals can be got by wells or bore-holes. Consequently
it is necessary to subdivide the subject into four heads :
1. Open works of all klndi, inclading hjdnulio mining.
2. EzoavaUon ol mineral! under water.
3. BztraetioD of minerali hy wells or boreholes.
4. VndergTcnuid workings.
O'BEN WOBES. — Some minerals are always obtained in this
way ; others are worked open before regular undereround mining
begins; and, thirdly, it often happens that underground and
Bunace workings are both being carried on simultaneously in adja-
cent parts of the same mine. Among the minerals worked open-
cast are the ores of copper, gold, iron, lead and tin, to say nothing
of all sorts of stone.
The advantages of open works may be summed up as follows :
(a) Complete remorsl of the mineral without any loss in the form of
(b) No expense or trouble as regards ventilation, men always working
in good ait ; no danger of exploBions.
'- e for ligbting, nnless work is carried on at night.
%l
izpense for timbering.
ibllitj of laying ont the work In larger steps o
can nsn^r be done In nndergroand working place
{e) Ponibllity of laying ont the work In largei
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286 ORE AND STONE-MINING.
On the other hand, there is usually the immense disadvantage
of it being necessary to remove a great deal of waste rock covering
the deposit, technically known as overburden. Work too ma;
be stopped by bad weather, such as heavy rain or snow ; open
auarrying may spoil land or interfere with roads or canals, so that
ae benefits do not all lie with the open works. The cryolite of
Greenland* is worked opencast from April to December, and dur-
ing the reet of the year the miners are employed below-ground.
One of the simplest cases of working away a mineral is that of
borax in California. The efflorescence has merely to be swept into
wind-rows and carted away to the refining works.
The beds of nitrate of soda in Chili are worked by large blasts
as shown in Fig. 54.t A .imall shaft is sunk a little below the
bottom of the "caliche" and enlarged in order to receive a charge
of slow burning powder made on the works. The esplositm
loosens and breaks up the ground over an area about twenty yards
in diameter. The hard overlying stratum of "costra" is then
easily removed, and the "caliche" is broken up into tumps, whidi
are taken to the lixiviating and crystallising works.
Generally the first process in an open working is the removal
of the overburden, and the manner in which this is done depends
upon the nature of the ground.
A first example may be taken from Northamptonshire, where very
large quantities of iron ore are obtained from beds of Jurassic age.
Similar beds are also worked in the counties of Lincoln and Oxford.
The actual bed of ore at Cranford in Northamptonshire is from
8 to iz feet thick, and the amount of overburden taken off is
sometimes as much as 20 feet ; when this thickness is exceeded the
ore can no longer be worked with profit.
The soil or " meat earth," which is from 8 inches to 2 feet deep,
is put aside carefully, for it has to be restored to make the surface
good and available for tillage. The remainder of the overburden is
cut away in one or more steps or " stopee," for the convenience and
safety of the workmen, the base of any step being usually about
equal to its height. The accompanying figure (324) represents
a pit at Kettering in Northamptonshire, in 1889, where 15 feet of
overburden were being removed from a i2-feet bed of ironstone.
The soil having been cleared offwith the shovel, the men undercut
the first stratum with a double-pointed pick at a and then drive
down a crowbar at b and another at a little distance from it. By
working the bars backwards and forwards they cause a big block
to break off along the dotted line. This crumbles in itfi fall, is
-shovelled into barrows, wheeled across the planks, and tipped on to
* " Die KryolitTeTUbeitDiig In der Breaondsaben Fabrik in EopeDhaKen,"
B. XL h. Z, 189J, p. 69.
t Robert Harre7, "Hacbineiy for the Maunf actnre of Nitrate of Soda at
•the ' Bamirei ' factory, Northern Chili," Proe. J«it. Cit. Eng., voL Ixzili.
1884-85, p. 341.
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EXPLOITATION. 387
tbe bank. After the top has bewi cleared away for a few feet, the
next bed U treated in the same way, and then the third, until the
ironstone is reached, and laid quite bare^ The ore can usually be
eaolT broken with the pick and at once loaded into amall wagons,
holding about a ton each. Occasionally a shot is fired, in order
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288 ORE AND STONE-MINING.
to IcMiseii parts that are hard. The loading ie done with an eight-
pronged fork, HO aa to separate the fine ore which the amelt«rt!
I'efuHe to take. If there is much fine, the ore is sifted ; one man
stands over a wheel-barrow holding a round sieve, with a half-
inch mesh, and another shovels the ore to bim. The fine drops
into the barrow and can be wheeled away, while the coarse is
thrown into the waffgon. The men working on the overburden
are paid per cubic yard, and those excavating ore are paid per ton
of ore placed in the trucks.
The working faces are long, in order that a large number of
men may be employed at one time. As surface rent must be paid
whilst the ground is useless, the soil is put back with the least
possible delay,aiid tillage then goeson once more upon fields which
have been lowered several feet. In the figure a small wa^on is
Fig. 3as. Fio. 316.
shown, but in some of the pits a full-sized railway waggon is
brought into the cutting and l(kded directly with 8 or 10 tons of
ironstone. When a slice 10 or iz feet wide has been removed all
along the face, the rails are shifted and a fresh cut taken.
The workings start, for instance, from some convenient point, C
(Fig. 325), connected to a main railway or wharf at X, and the first
line <rf workings is supposed ta be shown by CD, reaching to the
boundary of the property AB. The successive positions of the
working faces take such lines aaCB,CF,4c., radiating out fromC
as a centre, and all the ground CDK may have been given back to
the farmer, before the working face has assumed the position CP.
In hard rocks the steps maybe made very much higher. Thus,
at the great Penrhyn slate quarry, near Bangor, in North Wales,
the valuable slate and the valueless overburden are both taken
away by a series of terraces on an average 60 feet high by 30 feet
wide, as shown in Fig. 336.
The great opencast at Rio Tinto (Fig. 327) is a huge open pit
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EXPLOITATION.
389
from wHch the ore U got by a succeesion of etopea, benches or
terraces, 33 feet to 50 feet high. The pit is oral in shape, and
650 yards (600 m.) in length on the top of the ore.
Pig. 317.
A, cupreooH pyrites , B, slate , C, porphyry.
The opencast at the Mecberoich lead mine is also worked in a
eimilar manner. The Government regulations make it necessary
that the base of each step shall be at least 10 feet wide, so that
FiQ. 328.
stuff may not roll down from one floor on to the men working
below. The actual width is very much more, being usually 26 feet
(8 m.), whilst the height is 33 feet (10 m.)
When the rock is firm enough to stand for a great height, it is
i found convenient to take it down in one vertical slice
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ago ORE AND STONE-MINING.
without making a series of steps. The geDeral appearance o£
Mulberry mine,* near Bodmin in Cornwall, which is worked in this
manner, will be understood by a reference to Fig. 328. Men
standing at A bore and blast holes, which throw the rock to B,
under which a. level has been driven with an opening C, usually
closed by a covering of timber. A wa^;on is run in under this
opening and is easily filled.
Another method is that of firing a very lai^ blast, which
brings down thousands of tons of rock atatime. It is prepared by
FlQ. 319.
i
driving in a tunnel at right angles to the face of the quarry and
making one or more chambers, which are charged with gunpowder
or some other explosive ; the tunnel is tamped up like a gigantic
shothole, and the charge is fired by a fuse or by electricity.
As an example of a blast of this kind, I take some workiugg
for building stone nearMessina(Fig.329).t A tunnel was driven
into the face of the limestone quarry for a distance of 56 feet
(17m.), and then turned off at a right angle. The chamber
* C. Le Neve Foster, "On Some Tin Stockworke ia Cornwall," Quorl,
Jour, OeoL Hoc, voL xixlv. 187S, p. 655.
+ Fslangola, "8n11e GjaDdi mine nella loccia caloarea della catena
PeloritanB (Slcilia) e oelU rocoia granitioa di Baveno (Lago Magg^jore),"
Biviila di Artiglieria t Otnio, vol. ir. 1887, p. 343.
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EXPLOITATION. 291
«o formed was lined with a quick-setting cement in order to keep
out any moisture, and a cubical wooden box was built up inside and
charged with 64 bags of gunpowder, or in all 31 cwt. (1600 kil.)
Four ordinary fuses, plac«d in ft long box with sawdust,
furnished the means of firing the charge. The tunnel was then
filled up in the manner shown in Figs. 330 and 331. The object
of the slightly sinuous form of the tunnel was to increase the
resistance of the tamping.
The effect of the large blast was to break up and move more
4)han 100,000 cubic yards (80,000 cm.) of rock, with the advantage
Figs. 330 & 331.
DETAILS OF THE TUNNEL. r'^"-
SECTION ALONC THE LINES AB.BC.
(I, damp earth beateD in ; b, brick wall bailc with ci.
c, dr; Etoae wall ; <J, wall built with a qaick-setting cemenD ;
e, wall bnilt with hydraulic lime ; dimensions in metres.
of producing less small stone than would have been the case if the
ordinary method of quarrying had been employed. The dotted
line A B' C shows the outline of the face after the explosion.
We now come to an important class of workings, namely, recent
alluvial beds, such as river gravel containing diamondx, gold or tin
ore. The banks may be left high and dry when the river is low, or
the stream may he diverted and any pools drained by some simple
pump. The whole process of working often consists merely in dig-
ging up the earth with pick and shovel, andwashingit on the spot
witii a pan or batea. If there is not enough fall for discbarging the
refuse, in places where the operations are on a large scale, it
becomes necessary to raise the earth by some appliance, such as
■the hydraulic elevator (Fig. 34S)*
* Rickard, "Alluvial Mining In Otago," Tram. Amtr. Jail. il. K.
Tol. zxi. 1891, p. 445.
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292 ORE AND STONE-MINING.
Dame for diverting rivers are sometimes of considerable size.
For inHtance, on the Feather river, in. California, there is a dam
80 feet wide and 50 feet high. The water is carried off in a
" flume " or launder, 50 feet wide and 6 feet high.
The sand of beaches is occasionally scraped up at low tide and
washed for gold or tin ore.
HTdranlio Mining. — Under this head it is convenient to
include all methods of working in which water is used for breaking
away the sround, and not to restrict the term, as is most
commonly done, to the process of working auriferous gravel by a
jet of water under considerable pressure.
I will take some examples :
I. China Clay Working* in ContwaU* — The first operation is
the removal of the overburden, and a email shaft is then sunk in
A, ondecom posed grsDlte : B, decompoeed granite ; C, overboTden ;
D, eugine-honse ; BE, BE, sncoeBsive oatlluea of the open pit ;
(HI. shaft ; bb, level ; d, top of npriglit launder placed in the
email ehaft snuk in the middle of the deoomfioaed granite ;
ef. eolDmn of pumps throogh which the milkj stTesra of cbioa
clay and mica is lifted to the lauoder, /.
the middle of the area to be worked ; the bottom is put into com-
munication with the surface either by an adit level, if the contour
of the ground is favourable, or by a tunnel and shaft (Fig.
332), if the contour of the surface does not permit the driving
of an adit save at a prohibitory cost, or if it is more convenient
to have the settling pits close by. The shaft has to be fitted
with pumps. A stream of water is led on to the decomposed
granite, which the workman loosens with a heavy pick ; the
disintegrated particles are carried away in suspension to a first
settling pit, where the coarse grains of quartz are deposited, and
* Collins, The Htiubatroui Granile Dittrid, Trnro, 1878, p. 17.
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EXPLOITATION. 293
the milker stream then falls down the lavmder d, into the level
and either runs out naturally or is pumped up to the surface. It
passes OQ to other settling pits, and deposits first the mica and
then the vet? finely divided kaolin.
2. Auri/eroui Gra/vel — The process known as " booming," *
practised in Cahfomio, Colorado, Idaho and Montana, consists in
-discharging the contents of a reservoir all at once on to beds of
auriferous gravel. The powerful stream carries away the stones
and dirt into wooden troughs or launders, called " sluices," and
leaves behind the gold on the bed-rock, or in the upper part
of the run of sluices. In Peru f a simUar process is adopted.
By a natural transition from "booming," we come to
" bydraulicking," I a process in which a jet of water under
pressure is made to play against a bank of aunferous gravel, break
it down, disint^rate it, and wash it Into wooden troughs, arranged
so as to catch the gold by means of mercury on special floors, and
At the same time to discharge the stones, sand and mud.
For the purpose of storing a proper supply of water, large
reservoirs have to be constructed, sufficiently high above the gravel
hank to secure the necessary amount of pressure. They are
formed by erecting dams across the valleys, and they are made
«ither of earth, cribs of timber, or dry rubble masonry. One of
the largest in California is the Bowman reservoir, with a high
water area of 500 acres and a dam 100 feet high, which cost
^151,521, or speaking roughly ;^3o,ooo.
The water is taken to the place where it is required by (i)
ditches (" leats," £n^.) J (3) flumes; or (3) pipes, (i) Tha dibAei
are cut out on the sides of the hills, and the earth thrown out
serves to strengthen the lower hank. The shape most commonly
adopted for the ditches is a half-hexagon, or the upbank may be
made with an angle of 60° and the lower with 65*. The gradient
or ''grade " varies according to circuinstances from 7 to 20 feet
per mUe.
(2) Flwmea are merely wooden troughs, or " launders," as we
should call them in England. Figs. 333I and 334§ show the
manner in which theyare usually made and supported. In valleys
or caSons with very precipitous sides, the flume is sometimes car-
ried by iron brackets let into holes bored in the rock and hung by
* California iilate Mining Ilareau, Sinth Annual Report of the Statt
MiMralogittfor iht year tnding Peeember i, i88q, p. I2i aacramento 189a
Bowie, A Practical Treaiiie on Hi/draulic Mining in California, New York,
18S5, p. 81.
+ Kohlmorgen, "Die Qoldgtnben ¥on Caiabaja in Pern," Ji. u. k.
Zeltang, 1S90, p. 303.
t Thia aoooant of " hjdranlickitig ~ is ic
on Bowl«'ii Practieai Treatin on Hijdraulie
iSSs-
California," The Century
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ORE AND STONE-MINING.
iron rods (Fig. 335)* Where it is
poBsible, ditches should be put in
instead of flumes, because the latter
cost more for maintenance. They
also EuS'er more from wind, snow and
Btorms, and lastly they are liable t«
deetfuction from fire. On the other
hand, it may be impossible in some
cases to put in ditches, or the ground
may be too bard and too porous to
make a ditch advisable. When
water is scarce, the loss by g
and evaporation is a matter of i
portance.
(3) The third method of conveying
water ig by iron or aleel pipes. They
are useful in crossing a deep valley,
for they save the expense of con-
FiG. 334.
structing a very long ditch round its head, or
bridge acixtss it. Pipes crossing deep valleys a
• Bowie, op, clt.
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EXPLOITATION. 395
Biphona," although the principle of the siplion in no way comes into
pUy.
The pipes are made of riveted iron or steel, and one form of
joint is shown in Fig. 336,* made tight by running in lead and
caulking tt. The riveting may be straight or spiral. To prevent
rusting, the pipes are coated externally and iQtemallj with a
mixture of coal-tar and bitumen. Some of the pipee used for
conveying water in this way are 20 or even 30 inches in diameter,
and in such cases the thick'
ness of the iron is from No. Fia. 336.
16 to No. 14 B.W.G.
Whether broaght by
ditch, flume or pipe, the
water is led to the so-called
" preaaure-box " or "bulk-
head" (Figs. 337, 338, and
339 1), a cistern situated at
a sufficient elevation to give . . ' , . , ,.
th. i.t th. to™, it «,™. • ■■ ■ :r;;,f^,T„s;''; iitiSri™
The dStem is strongly made, ^.^^ „{ the pipe d, each length having
and has a grating A to a similai nipple,
catch floating sticks which
might otherwise choke the pipe. At the bottom there is a recep-
tacle B to receive gravel and sand, which are discharged from
time to time by opening a hatch at C.
The pipe leading away from the pressure-box is simUor to that
used for crossing vaUeys, and it is brought down into the
workings ; if it is advisable to attack the bank in two places at
once, the pipe is forked, each branch having its valve. The pipe
terminates in a nozzle from 5 to 9 inches in diameter known as a
• Bowie, op. eii. + Bowie, op. at.
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29^
ORE AND STONE-MIKING,
" monitor." The monitor ehown in Pig, 340 * is provided with an
arr&Dgement by means of which one man can deflect it vith
great ease. IE the nossle B is in a straight line with A, the
stream passes through it unimpeded ; when it becomes necess&iy
to turn the water on to another part of the gravel bank, the lever
0 is held to the side to which the jet has to be deflected. The
pressure of the water in B then moves the monitor as
desired.
The manner of using the powerful jet of water to wash down
banks of gravel is well depicted in Fig. 341, borrowed from Mr.
Evans' interesting article.
If the gravel is cemented into a hard conglomerate, drifts
* Bowie, op. cit.
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EXPLOITATION. 297
are run into the bank ; they are chained with a number of 251b.
kegs of powder, tamped up, and fired by electricity. The jets of
water will then do the rest.
The gravel washed down by the jets of water is led first into
ditches cut in the "bed-rock," and then into "sluices." Sluices
are large troughs or launders lying upon the ground, and paved
with loose blocks of wood or with stones, in order to form a
Fig. 341.
surface fit for catchiag the gold and the amalgam. Figs. 342, 343,
and 344,* show a section, elevation and plan of a sluice-box with
two kinds of lining ordinarily adopted. It will be seen that
the sluice in this case is a trough 5 feet 3 inches wide, made of
1) inch plank at the sdes and a-ioch plank at the bottom, upon
which are placed blocks of wood zo^ inches square, and 13 inches
deep, set with the grain on end. They are separated at the
bottom by cross strips of wood i i inches thick, and the sides are
protected by blocks 3 inches thick. At one end the paving is of
large stones.
The sluice is generally made in twelve-foot lengths, and the
inclination is commonly defined by the fall given to such a length.
• Bowie, op. cil., p, 222.
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agS ORE AND STONE-MINING.
FIO. 34a
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EXPLOITATION. 299
Thus it is said that the grade is 6 inches, meaning 6 inches to
12 feet or ^ inch to the foot. The run of sluices may ba several
hundred or BeTeral thousand feet long.
The fake-bottoms for sluices are called "riffles." The wood
prefen-ed for the block-riffles is that of the "digger" pine {Pinua
safnniana). Longitudinal riffles are made of poles, wooden rails
covered with stripe of iron, or iron rails, In New Zealand* the
riffles are sometimes made of transverse bars of angle-iron, riveted
to angle-iron or placed in a wooden frame, which enables them to
be reversed when worn. The sluice-boxes are lined with thin
sheet iron, and sacking or cocoa-nut matting is placed under the
riffles to assist in retaining the gold.
In order to catch Its gold more effectually, the finer material
is taken out and treated separately in broad sluices called " under-
corrents," at the side of the main one. A grating of bars of
iron, 1 inch apart, called a "grizzly," is fixed across the main
sluice, and the fine gravel and sand which drop through are led
to a broad, shallow, sloping box, eight or ten times as wide as the
sluice itself, and paved hke it with stones, wooden blocks, or
longitudinal riffles. The finer portions of the gravel, after passing
over the " undercurrent " and depositing much of their gold, are
once more turned into the main sluice lower down.
The big boulders rushing down the sluice are of service at first
by breaking up gravel which is much cemented together, but at
the same time they naturally wear out the sides and the pavement.
It is therefore advisable to get rid of them, as soOD as they have
done all the useful work they are capable of periorming. This i»
effected by arranging a "grizzly" or grating which will deliver
the boulders into a ravine or gully, and so dispose of them without
any further cost.
Mercury is added several times a day at the head of the
sluice; and the upper part, say, the first 1000 feet, is cleaned up
every two or thi-ee weeks. At the time of the clean-up the
washing down of the gravel hank is stopped, or the current is
diverted into a parallel line of sluices. A small quantity of water
is turned into the aluice which is to be cleaned up, the blocks are
then taken out, washed, and put on one side. All the amalgam
is picked up with iron scoops, washed, and squeezed through
canvas or leather, and the amalgam is retorted. The spongy
gold remaining behind in the retorts is then finally melted
into bars. The mercury recovered by condensation is used over
again.
When the bed-rock is below the drainage level, the hydraulic
elevator " may be employed. A jet of water under heavy pressure
m Zealaitd, WeUlngtOD
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300
ORE AND STONE-MINING.
la brought by & pipe A (Figs- 345 to 348) to the notzle B, and
rushes up the pipe D, producing a powerful suction in the
" hopper" 0. The water and gravel are carried up against tlie
cast-iiron striking plate S, and then run down the aluice-boxes,
Fm. 345-
Fig- 349 explains the method of using the elevator Cor treating
an immense accumulation of taUiogs at the Slue Spur, Otago,
N.Z. On the left hand side ia a huge nozzle playing upon the
face of the tailings, 59 feet high, and washing down the gravel
and sand of which they are composed. To the right is the first
elevator, which raises the stuff 15^ feet into a set of sluice-boseu,
and further to the right is a second elevator lifting it 56 feet
vertically into another run of sluice-boxes.
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EXPLOITATION. 301
The quantity of water used is measured by a unit called the
" miDer'a inch," • which unfortunately ia not invarinbly the same.
The term means the quantity of water discharged per square
inch of sectional area of an orifice cut through a vertical board,
forming one side of a box. The discharge will necessarily vary
witb the height of the surface of the water above the orifice, the
thickness of the board, and the shape and nature of the oriiBce ;
ae these factors of the problem are not the same in all localitieB,
it is impossible to give one definite value for the miner's inch of
water. The orifice is usually rectangular, but it may differ in height
and width. However, the quantity represented by the miner'*
inch may be taken as varying from 2000 to 2600 cubic feet per
Fia. 349-
24 hours; insomecases the outflow is reckoned for 10 hours only,
and is spoken of as the " ten hours miner's inch."
Under these circumstances it is evident that great celto must
be taken to ascertain precisely what inch is meant, before making
any estimates based upon this uncertain unit, the miner's inch.
The " duty " of the miner's inch ia " the quantity of material
washed by an inch of water in 34 hours." As might be
expected, the duty varies very considerably, indeed from 1 to 4!
cubic yards. The duty neceesaiily depends upon the pressure of
the jet of water, and upon other causes, such as " character of
the material washed, height of banks, use of explosives, size and
grade of sluices, and class of riffles. The sluice affects the duty
of the inch in so far as ibi capacity regulates the quantity
washed." t
Under favourable conditions at Cherokee Flat,^ — viz., fine
* " Tbs AariferonB Gravela of California," A7iW A .dnnunl Rejxn-t of the
SUtU Mineraloffial JOT the year ending Dectmbtr 1, 18S9 ; Sacramento, 1890,
p. 123 ; and Bowie, op. cit. p. 124.
t Bowie, op. eit. p. a68. t Bowie, op. at. pp. 368, 269.
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302 ORE AND STONE-MINING.
material, high bankn, head of 300 to 350 feet, and grade ^,
5'5 cubic yards are Baid to be the duty of the miner's iDch.
At Osceola,* in Nevada, the average washing in 1890 was i'6i
cubic yards to the inch of water and it was expected that the
duty would be raised eventually to z cubic yards.
It is hardly necessaiy to say that the yield of the gravel varies
between very wide limits, and it is consequently impoeeible to lay
down any average for the hydraulic mines of Galifoniia or any
other country. But the accompanying table gives the results of
actual work, and will at all events show that poor gravel, con-
taining gold worth only 10 or 15 cents, say, $d. to ^^d. per cubic
yard, can sometimes be made to pay good profits.
With the exception of Osceola, the works were all in California ;
the figures are borrowed from Mr. Sowie, and many other ex-
amples of the yield of auriferous gravel will be found in hia work
and in Mr. Hammond's report.
A cubic yard of grovel is estimated by Mr. Hammond to weigh
from i^ to I J tons.
One of the great di£Scultics with which the hydraulic miner has
to contend is getting rid of the enormous quantities of refuse
produced by his waahings. Bome idea of these quantities will be
gathered from the statement that one working alone, the Geld
Run Ditch and Mining Company, was for & period of eight years
discharging 4000 to 5000 cubic yards of sand, giuvel and boulders
daily into a tributary of the Sacramento. As a natural con-
sequence banks were formed in the river, obstructing the
navigable channels, rendering overflows more frequent and
destructive, and causing valuable land to be destroyed by de-
posits of sand. Litigation ensued, and some years ago the
Superior Court of Sacramento decided that the hydraulic mining
companies must build dams to impound the coai'se and heavy
debris, or take other means to prevent their being washed down
the rivers.
The consequence of this decision was a great diminution of the
amount of hydraulic mining carried on in the State ; but quite
lately an Act of Congress has been passed which will allow work
to be resumed at many of the mines.
<2) EXCAVATION OF MIITEBAIiS TJITDEB WATEB.
— In Chapter lY. mention was made of dredges of various typee,
which are employed for the purpose of extracting gold-bearing
sand and gravel from the beds of rivers. Gold is not the only
mineral worked in this fashion ; in South Carolina phosphate of
lime is dredged up from river-bottoms, and in Pnuce Edward
Tsland a shdl-marl obtained in a similar manner is sold as a
fertiliser. Lastly, on the coast of Germany, between Dantzig and
Memel, two forms of subaqueous work are applied to the getting
• Sag. Min. Joitr., voJ, li., 1891, p. 630.
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EXPLOITATION.
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, Google
304 ORE AND STONE-MINING.
of amber,* Some is dredged up by bucket-dredges, and Bome is
obtained by divers. The divers go out in boate about three-
quarters of a mile off the Briieter Ort lighthouse, and after
anchoring they descend to work the amber bed, being equipped
with regular diving drenses, and supplied with air by pumps
worked by their comrades. Carrying a crowbar and a pronged
iron, the luver searches for masses or lumps of amber and detaches
them from the parent bed, or finds them already loosened and
dislodged by storms.
(3) XXTBACTIOn- OF MINERAXA BY WELLS AZTD
BOBEHOLX8. — Liquid, gaseous and soluble minerals are
sometimes obtained by one of these two methods. The principal
are : carbonic acid, natural infl&mmable gas, petroleum, and salt.
Carbonic Acid. — TJndergi-ouod supplies are tapped by bore-
holes, and the getting consists simply in piping off the gas from
the top.
Xatured ^iw.^-Frecisely the same remark apphee in the case of
the natural gas used for fuel in Pennsylvania, the occurrence of
which has already been described.
Petroleum. — Thb mineral may be got either by wells or bore-
holes. In the United States, in G&Uci&, and in the great oU<
district on the Caspian Bea, boreholes are sunk by one of the
processes described in Chapter III., and it is found that the oil
will either rise to the surface or part way to the surfacn. In this
latter case it has to be drawn up by pumps. In order to increase
the Sow of oil from the surrounding rocks into the bore-hole, it
is usual to break up and crack the oil-bearing stratum by a
torpedo. This is a powerful charge of some explosive con-
tained in a tin cylinder, which is lowered into the hole to the
required depth and then exploded. Nitroglycerine, dynamite or
gunpowder aro employed, but of course the last is only used when
its more powerful rivals cannot be obtained. As much as a
hundred quarts of nitroglycerine may be used for one blast, in
which case the explosive is let down in separate <yllndere, each
containing twenty quarts. The explosion of the top cylinder fires
the charges in the others.
In Burmah the petroleum is got by wells, and this was the
manner by which the great Russian deposits were worked until
comparatively lately. The oil gradually oozes out of the sur-
rounding strata and accumulates in the bottom of the well, whence
it is drawn up by earthenware pots.
S(di. — The great bed of salt at and near Middlesbrough is
worked h^ making a borehole and putting in two tubes and a
pump, so arranged that water from a superincumbent bed of
sandstone travels down, dissolves the salt, and is then drawn up.
The process pursued will be apparent from an inspection of the
* " Tbe Amber Fisheries of the Baltic," Evening SUmdttrd, Sept iz, 18S8.
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EXPLOITATION.
305
£gaK. A drive-pipe aa (Fig. 350) is first rammed down through
the alluvial soil, in the manner described by Fig. 142, and a borehole,
8 iochea in diameter, is put down through the sandstone, gypeeous
marl, and the whole thic^ese of the rock-salt, until it luie reached
FiO. 350,
-Wat^r-biarln
, ' SaiHlwloiit
the imderlfiiig aohydrite. It now has to be lined with a steel
tabe bb (Fig. 350, in which the site of the tubes is greatly
exaggerated), 6f inches in diameter intemalljr; for the finit 150
feet m)m the bottom the steel is ^ inch thick, then A inch for
300 feet, and the remainder is | inch thick. With tiie sleeve
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3o6 OKE AND STONE-MINING.
ooupli&ga over them, the tubae just pasa down the drive-pipe. In
the ro<£-Balt and in the 600 feet of water-bearing sandstone,
the lining pipe is perforated with holes i inch in diameter, and
1 2 incbee apart vertioally.
lastly, a Bteel suction pipe (Fig 350, c), 3 inches in diameter
internally, and \ inch thiok, made in 30-feet lengths, united by
sleeve couplings, is lowered into the borehole; about 240 feet
from the surface is fixed a brass working barrel (Fig. 350, d), 6 feet
long, 4J inches in diameter and j inch thick, and above it Bt«el
tube«, 43 inches in diameter, which reach to the surface. Hie
working bairel has a ball valve at the bottom. When the pump
bucket, also fitted with a ball valve, has been let down by a series
of ronls, aad the last one has been connected to the end of the
walking beam, the extraction of brine cen commence. It is
evident from ijie figure that when a pump is set in motion at d,
water will ascend the suction pipe, and its place will be taken by
water from the sandstone. This descends the outer tube to the
rock-salt, brings it into solution, and is pumped up as brine.
As the pumping proceeds, the rock-salt is gradually eaten away
all round the borehole ; in time the marl roof must fall in, and
eventually the pipes will get more or lees choked, and the brine
will be too we^ to be worth pumping.
The rate of pumping is regulated so that the brine is delivered
with 25 per cent, of salt. As it comes
1^0. 351- up it is full of gas, which is mainly
° nitrogen with a small proportion of
hydrocarbons.
Ihe borehole are arranged in fours
at the comers of a square, with a
^ , eoofb-- *. ^^K^"^ "' '°° *®®* C^g- 351)-
The brine is delivered into a large
storage and aettling-pond, whence it
flows into sheet-irpn evaporating
pans.
, If there is no natural supply avail-
able, as is the case in the Middles-
brough district, fresh water from the surface ia run down the
out«r pipe, and the dissolving proceeds as before.
Natuml sheets of saline water or brine can be tapped by wells
or boreholes in some districts ; indeed salt was worked in this
way in Cheshire long before the discovery of the rock-salt. Some
of the Cheshire salt is derived from brine pumped up from
inundated mines worked originally for rock-salt, which are now
full of water and cannot be entered.
This therefore is practically a combination of underground work
with extraction by solution, and the process which in these cases
has been finally adopted, through force of circumstances, is some-
times found advisable from the commencement.
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EXPLOITATION. 307
Gallon* describes and figures the method of working the salt
marls of the Salzkammergut by huge elliptical chambers. A
network of drivagea is first of all made at the fioor of the proposed
chamber, and then fresh water is brought in, until it fills the
excavations and gradually eats away the pillars and roof. The
brine is pumped up and the clayey matter falls on the floor of the
chamber and is left there.
At Bex in Switzerland the process la similar, only it has
to be adapted to the nature of the deport worked. The salt
•occurs in the form of large lenticular masses of saliferous
anhydrite surrounded by anhydrite free from salt. The lenses
are from 10 to 50 metres wide, and are known to extend to a
-depth of 300 or 400 metres, dipping almost vertically.
A main shaft is Hunk and the saliferous rock is reached by cross-
cuts and dissolved away in slices 100 metres thick at a time.
An intermediate shaft, or winze, is sunk from the crosscut,
and when It has reached a depth of 100 metres a second ci-osscut
is put out, from which two long drivagee, 2 metres high and
i-gom. wide, are made in the direction of the major axis of the
'deposit. By a series of drivages at right angles to each other,
the lowest part of the slice is cut up into a set of square pilars
about 5 or 6 metres on the side. Water is let into the winze, and
is allowed to rise to the level of the upper crosscut. It dissolves
the salt from the rock, is pumped up, piped out to the surface
through a long adit, and evaporated. As the strongest brine
sinks to the bottom, the pumps are made to take their supply from
the lowest part of the workings. The saliferous anhydrite contains
from 25 to 30 per cent, of salt, and when this has been dis-
solved out, the rock does not fall to pieces as might have been
expected. Oypeum is soluble in wat«r containing 10 to 14 per
cent, of salt, so the first action of the wat«r is to dissolve some
of the anhydrite ; but when the brine becomes more concentrated,
gypsum is depositod in the form of small crystals, which bind
the anhydrito into a firm mass. Consequently the leached rock
stands perfectly well by itself, and there is no fear of the sides
falling in.
One of these large workings, when once properly laid out, will
go on furnishing brine for thirty or forty years. The rate of
pumping is regulated so as to supply brine with 35 to 36 per oent.
of salt.
A last instance of a combination of underground workings and
extraction by watery solution may be taken from Parys Mountain
in the island of Anglesey. During the active working of the
Parys mine many years ago, poor copper ore which had been
broken, but which would not pay for the expense of winding and
-dressing, was left underground. Under the action of air and
* Lecture* or Mining, toL iL. p. 23 ; Atlts, plato xliii. Figs. 251, 252.
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3o8 ORE AND STONE-MrNING.
moisture, the chalcopyrite in the refuae and in tbe pillars is
gradu^ly decomposed, producing a certain quantity of soluble
sulphate of copper. Ram finding ite way down the mine diesolvea
the sulphate, and the pumps draw up a strongly coloured water,
which in contact with scrap iron yields merchantable copper
precipitate. The mine is now worked solely in this way.
In a like manner a little copper has been got from the water
flowing out of the County adit in Cornwall.
(4) TJNDEBaBOUITD WOBEI]S'aS.--The methods em-
ployed for excavating minerals underground are almost aa various
as the different forms in which the minerals themselves occur.
The deposit must first be reached by a shaft, or, where
the contour of the countiy ipermits it, by an adit. The choice
betweeo these two methods of attack most be entirely governed
by the circumstances of the case. In a comparatively level country,
it would be impossible to bring in an adit capable of rendering
any real service without going to a distance which would make the
cost of driving prohibitory; but among the mountains an adit
may be the quickest and cheapest means of entering productive
ground. It has the advantage of enabling all pumping to be
dispensed with for a time, of reducing subsequent water-barges,
of affording an opportunity of easily utilising water supplies in
the neighbourhood, and often of bringing out the mineral to a
more suitable locality for treatment than could be obtained by
raising it perpendicularly to the surface. Instances often occur
in which the adit can be driven along the course of the depceit
itself, and so furnish valuable data concerning it. A shaft
sunk upon the dip of a deposit has this same advantage ; but
here it is necessary to remark that the term " shaft " does not
always convey the same meaning. The ore-miner uses the word
to denote not only a vertical pit, but also one sunk upon a vein,
even if the inclination is but slight. There are portions of shafts
in Cornwall which do not dip more than 15 deijreos from the
horizontal. Shafts with an inclination of 60° or 70° from the
horizontal are common in vein-mining, and no ore-miner would
think of calhng them by any other name. On the other hand,
the coal-miaer seems to confine the word shaft to vertical pits.
If a pit is sunk vertically till it meets a seam of coal, and is then
continued along the dip of the bed, the latter sloping part of the
excavation, even if it has a dip of 50° or 60°, is csJIed on "in-
cline," and not a shaft. The term " slope" is used in places to
denote an inclined pit along the dip of the strata.
We wilt suppose that the deposit has been struck by a shaft,
incline, or level. The problem is how to remove it to the beet
advantage. As the conditions are so various, it is advisable to
classify the methods according to the nature of the deposit, and
treat separately the modes of working — (i) beds ; (2) veins ; and
(3) masses.
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EXPLOITATION. 309
BEDS. — Two great diviaions stand out prominently :
(A) Methods in which the bed is cut out into pillars ; and
(S) methods in which the bed is removed at once without this
Iireliminaij treatment. In the former the piUars maj* either be
eft as permanent supports, or they may be removed in a second
stage of the process of exploitation. We have thus three prin-
cipal processes of working to consider, as shown in the following
table:
(Ai. Pillars left as permaueDt sapports.
{A. Rllar workings. J
BodB J (Az. Pillars worked away.
(B. LoDgwall workiogii.
Ai. Pillars Left as Permanent Supports. — This system
is adopted with minerals of no great intrinsic value, as it is oft«n
better to lose much of the mineral in the form of pillars, than to
go to the es:pense of putting in artificial supports during the
period of exploitation.
The method can be best understood by giving a few charac-
teristic examples taken from minerals
of various kmds — viz., gypsum, iron Figs. 351 & 353.
pyrites, limestone, salt, and slate.
Gt/psuTn. — Figs. 352 and 353 I'epre-
sent in section and in plan the cham-
bers and pillars of the underground
gypsum quarries at Paris, which supply
the stone from which the well-known
plaster is made.* The principal bed
is from 50 to 60 feet in thickness.
PillarB are left 10 feet square at the . □ 0 S fe
base, and the slaila between them are ^
16 feet wide. The workings are slightly 13 O ^ S
arched, and are not carried up to the
true roof, for the purpose of better maintaining the security of the
chambers, because heavy damages would have to be paid if they
" caved in " and rendered the surface useless, A similar layer of
gypsum left for the floor prevents "creep" — that is to say, arising
of the floor owing to the thrust of the pillars, and enables the
underground roads to be kept in order with little expense.
In Nottinghamshire the poor parts of the bed of gypsum are
left as pillars, and they are sufficiently frequent to prevent any
waste of good rock for supports.
Iron Pj/rites. — At Cae Coch Mine, near Llanrwst in North
Wales, there is a bed of iron pyrites, about 8 feet thick, which
is worked by leaving pillars from z to 3 yards in diameter, at
intervals of 8 or 10 yards. The pillars are somewhat irregular,
because where the roof is firm and strong more space can be
* CalloD, La:lurei on Hiaiiig, vol. ii. plate xli.
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3IO
ORE AND STONE-MDSING.
left without support. If the roof appeara at all wenk, ,the-
pillarB are made closer together. The excavations are slightly^
arched at the top, bo as to obtain a little more strength.
LimetUmt. — A conHiderable qu&ntitj of limestone is wrought
in this country by underground mining, especially in Wiltahire,
WoPoeBtershire, South Statfordshire, and Scotland.
The beds of freestone which are worked near Bath occur in the
Great OoUte, and vary from S or 9 to i8 or 34 feet in thicknesfi \.
the dip is slight, being only i in 33.
Fio. 355.
^ Snt-on
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FiGF. 3S4.
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i
The bed of stone, which it is proposed to work, is reached by
an inclined plane, and a main heading is driven out 15 to 16-
feet wide, with " side holes " at right angles, aa wide an the
roof or ceiling will admit with safety, say zo feet to 24 feet,
leaving pillars 10 feet square and upwards (Fig. 354). If any
rock is unsound, it is left as a pillar, and this may cause some
irregularity in the plan of the mine.
The first process in removing the stone consists in excavating^
the " jad," a horizontal groove at the top of the bed, which is
cut in for a depth of 5 feet
Fia. 356. and a width of 20 to 25
feet (Figs. 355 and 356).
After the jad has beea
excavated with the pick
(Fig. 355), a vertical cut is
made with a saw along the
line BA (Fig. 356), and
another along tJie line DC,
and a piece ABDC, called the " wrist," is wedged up from the
bottom or off from the side ; it breaks along the line AC. When
the "wrist" has been removed, the blocks are simply cut out
with eaws. These saws are 6 or $ feet long by to inches to 12
inches wide. The first saw used in the jad has to be narrower,
aud is called the " razor saw."
The heaviest saw weighs 56 Ibe., and the handle can be fixed
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EXPLOITATION. 3"
as shown by the doited linea (Fig. 156), or entirely below the eye
for working immediately below the roof.
When Bet free by sawing on all four sides, the block ie easily
detachod by wedges driven in along a plane of bedding. The
blocks are lifted off by cranes, and either loaded at once on to
trucks or stacked inside the quarry, after having been roughly
dreesed with an axe or with a saw.
A workman can saw 15 square feet of the softest beds in an
hour.
In the neighbourhood of Dudley there are two beds of Upper
Silurian limestone worked by true mining. The top bed is from
16 to 18 feet thick, and it is got by a system of pillars and
chambers. The pillars are 8 yards square, and the ataUs between
them 13 to 17 y^-ds. Near the outcrop both the pillars and the
fitalls are rather smaller than this. The top 2 feet of stone are
left to support the roof.
Salt. — The salt mines of Cheshire* are an excellent example of
pillar and chamber workings. The bed is S4 feet thick, but only
Fio. 357. Via. 358.
the bottom part, 15 to 18 feet thick, is mined. Pillars 10 yards
square are left promiscuously, about 25 yards apart, or closer if
thought desirable in any special places. Fig. 357 represents part of
Maraton Hall Mine near Nortbwich. The bed is almost horizontal,
and ie reached by two perpendicular shafts ; wide stalls are then
driven oat on all sides. The workings are advanced by making
an excavation in the upper part called the "roofing" (a. Fig. 358);
and the lower two-thirds of the thickness worked are got by
blasting slanting holes. This part is called the " benching." The
roofing is made by holing or under-cutting by hand, or better by
a Wa&er circular saw driven by compre^ed air (Fig. 216), and
bringing away the salt by horizontal holes bored with a jumper
and charged with gunpowder.
The qld method of working salt in Boumania f was by bell-
shaped pits, which were widened out gradually till their diameter
* DickioBon, ''Reports on the Salt District!," JicportioftheJntpttioTio/
JUina/m- the Year 1S81, p. 66.
t Nolict tnrla Romaarat. Expoiition Vmverialle de ibm«n /SS^, pp. tl6
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312 ORE AND STONE-MINING.
reached i6o to zoo feet (50 to 60 m.), after which the sides were
carried down vertically.
Now&dajrg long ohambera are excavated with intervening pillars.
A chamber is begun by driving a level 10 to 50 feet wide
(3 to 16 m.), and this is deepened and widened at the same time,
so that the sides make an angle of 30* to 45*, untU the fall width
of 164 feet (com.), is attained; the ezcavatioD is then continued
with vertical sides. The section therefore resembles that of au
ordinary house. A gangway is carried round the roof for the
purpose of inspecting it regularly.
At Turgu-Ocoa Mine there are four of these chambers which
will eventually vary from 100 to 160 feet in width (30 to 49 m.)
and 450 to 560 feet (138 to 170 m.) in length, and afford a total
working area of 32,000 square yards (18,550 square metres).
As regular blocks of ahnost uniform weight are preferred for
exportation, great pains are taken to get out the rock-salt in
the form which meets with the readiest sale, and to reduce the
quantity of " smalls " to a minimiim. The blocks are cut by hand
or l^ machine. Three cutting machines are used : one makes
horizontal cuts in the direction of the long axis of the chamber,
the second vertical cuts, and the third transverse cuts, so as to
divide the rock-salt into regular cubes, about one foot on the side,
weighing 132 lbs. each (60 kil.).
Slate.— lo the Festiniog district in North Wales the principal
bed is 120 feet (36J metres) thick in places, and there are others
from 30 to 70 feet thick ; these beds are spoken of as " veins,"
though they are true sedimentary deposits. The dip of the beds
is from 20° to 30° or 35°, whilst the dip of the planes of cleava^
is about 45'; the strike of the planes of cleavage is vei7 nearly
the same as the strike of the planes of bedding.
T^e method of working oonsiets in making a series of parallel
chambers {openinga) separated by pillars (icaUa). These do not
follow the dip, but run somewhat askew, because it is found
that the slate rends w^ at right angles to the cleavage planes
in a direction which does not coincide with the dip exactly. The
width of the cfaambere along the line of strike varies accord-
ing to the firmness of the bed selected as roof of the chamber,
and is commonly from 35 to 50 feet. The width of the inter-
vening pUlars b usually somewhat less.
The workings are divided into a succession of floors about 50 feet
one below the other vertically. The firstoperation consists in reach-
ing the bed by means of an adit or an incline sunk along the dip of
the bed and then levels are driven out along the strike, A B 0 D (Fig.
359, plan ; Fig. 360, cross section), under some bed which offers the
necessary guarantee of solidity, very often an altered volcanic ash.
When a new level, such as D (Fig. 360), has been driven a certain
distance it is connected with the level above by an inclined drift
called a " roof." The " roof," or " rise " as it would be called by
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EXPLOITATION.
313
an ore-miner, is a passage about 4 feet high, and 4 feet wide,
generally excavated from below upwards, on account of its being
more economical to let the broken rock fall into the level underneath
than to draw it up by hand, which becomes necessary if the passage
is made by "sinking" — i.e., excavating from above downwards.
The "roof" is usually carried up on one side of the proposed new
chamber. The third step in the process is the " widening," or
excavation of the rock on one side of the " roof," until the slate is
uncovered for a width of 40 or 50 feet. The result of this work is
the formation of an inclined open space 40 feet long, for instance,
along the strike, and stretching up from one level to the next one
50 feet above it vertically. While this work is going on, the
level is being prolonged ; a distance of 30, 40 or 50 feet ia
left for the pillar, and eventually a new "roof " is put up for a
second chamber.
Id most cases the excavation of the "roof" «id the procens
na. 3S9- Fig- 360. Fio. 361.
of widening go on at the same time, because it is found tbat the
atmosphere of a small passage tike a " roof " naturally becomes
bad daring work, unless it is provided with some special venti-
lating appliance, whereas if the amount of space is increased, the
impurities introduced into the atmosphere are spread over a
greater volume of air, and the evil is lessened.
This preliminary work of driving levels, " roofing up," and
" widening," is all done by a spe^al set of men, known ns
" miners," to distinguish them from the slat^-getters, who are
called " rockmen," for slate is par excetlenat " the rock " in the
district.
The productive period of the life of a chamber now begins.
The first duty of the rockmen is to examine very carefully the
roof of the chamber, which ought to have been left perfectly
secure by the miners ; but as the rockmen have to work under
it possibly for ten years or more, they naturally are anxious to
feel that every chance of a fall has been prevented as far aa
possible. In the early part of the working of a chamber, when
the roof is within reach, the examination can be made with ease;
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314 ORE AND STONE-MINING.
later on when the sl&te has been exc&vated, or partly excavated,
long ladders are required, and the task becomes much more
difficult.
Having satisfied themselvee and the agents that all is safe, the
rockmen |)roceed to remove, bit by bit, the huge mass of slate
lying between their floor and the one above it. Such a mass will
sometimes be sufficient to produce merchantable slate worth
^10,000 or even ^15,000, and to give work to a small gang of
men for fifteen years.
In the plan (Fig. 3 5 9), the lines FP* are the sides of the chambers
and also indicate the direction of the " pillaring." When the slate
is taken away a large chamber is left, and the series of chambers
one above the other forms a huge continuous inclined opening
stretching down from the surface, it m&y be, for a distance
of several hundred yards. Between each two of such openings,
there is the supporting pillar, nearly if not ignite equal in site to
that of the excavation. The consequence is ihat very nearly one-
half of the available slate is lost in the form of pillars; much
again is entirely wasted in making the preliminary drivage, the
" roof," the " widening," and the " free aide." There is a further
loss in getting the blocks and, as we shall see later on, in making
these into marketable roofing slates or slabs. Indeed it is
reckoned that even a good " vein " will yield only about 40 per
cent, in the form of blocks, and that two-thirds of tliis are waited
in the subsequent dressing. Therefore, the slate miner doed not
sell more than one-tenth to one-sixth of the slate rock which he
lays bare in a chamber, to say nothing whatever of the loss in
the form of pillars, which have to be left in the mine as perma-
nent supports.
There are varieties of this method of working. For instance,
at Aberllefenny in Merionethshire,* a bed 60 feet thick, dipping at
an angle of 70°, is worked by alternate pillars and chambers with
a much smaller loss in supporting rock. The pillara are from
24 to 30 feet long, and the chambers 100 to 187 feet along the
line of strike. Indeed even at Fetitiniog, there are chamlx^ at
Wrysgan Mine, where the roof is very strong, more than 130 feet
in length, whilst the pillars are only 50 feet.
At Angers, in EVance, the beds dip at a high angle, and the
underground workings are carried on like an open quarry
under a strong roof ot slate; the floor is being continually
worked away in steps, and an immense open chamber is left vrith
perpendicular sides.
In the French Ardennes the beds of slate are inclined at lower
angles, and in this respect more resemble those at Festiniog;
but the pillars run indefinitely along the strike, instead of
approaching the line of dip. The cross-section (Fig. 361) shows
1 Aberllefeimj Slate Mine," Trasi. B.
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EXPLOITATION. 315
these pUlars AA, and the chambers between them. The
attack of the bed is made from below, and not from above aa in
Walee, and the slate is removed slice after slice parallel to the
bedding. The men stand upon the rubbish, which finally fills up
the chambers completely. In the figure the upper chamber is
exhausted, the nert one is half worked out, and in the lowest
only one slice has been taken off.
This method of mining is favoured by the presence of natural
joints, which can be utiUsed for forming the roofs of the chambers
without any cutting.
In this case the walls of the excavation are supported
eventually, not only by the pillars, but also by the rubbi^, and
other instances may be found where a filling up with wa«te rock
constitutes a feature of the method of working. For instance, the
thick seam of carnallite or kainite at Sta«sfurt is worked by huge
chambers, between which pillars are left. The Frusaian Govern-
ment, fearing that, in spite of wide pillani, a " caving-in " may
poesibly occur, has ordered ajl the excavations to be filled up.
The cheapest method of doing this is by working out chambers in
the bed <^ rock-salt, tying geologically below the potash salts,
and using the salt as stowing. The chambers in the rock-salt
stand well without fear of the roof giving way.
At the Wieliczka salt mines it has been found that the natural
pillars, originally supposed to afford ample support, are not always
capable of preventing the roof from falling, and in some places
they are supplemented by hugs timber frames (Fig. 268), which
are nothing more than " oogs " or " pigsties," on a gigantic scale.
As. FUlar 'Workings with Temporary Pillars. — It is
naturally far more satisfactory from an economic point of view
to leave as little of a deposit aa possible : a larger output can
be got from a given workmg area if everything is removed, and
it seems a pity after a bed of mineral has been discovered, and
after all the dead work of sinking shafts and driving levels
has been accomplished, to allow any of the valuable material,
the very object of the mining, to be left behind. We therefore
now come to the cases in which driving galleries and cutting
up the bed into pillars form only a first stage in the actual
expl<»tation.
The most important example in this country, after coal, is the
mining of ironstone in the Cleveland district. The bed has an
average thickness of about 12 feet (Fig. 43) where worked.
If the contour of the country is not suitable for bringing in
adit levels, two vertical shafts are sunk, one of which is shown
in Fig. 362. An almost level road, the mainway, is driven out
with a width of 5 yards ; drivages are put out, at right angles
to it, at intervals of 20 yards, called b»rda, also 5 yards wide,
and at distances of 30 yards apart cross-drivages are made, called
vxUlt. These are only 4 yards wida By this system of galleries,
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3x6 ORE AND STONE-MINING.
the bed is cut up into a series of ptllare, 30 yarde long by 30 yards
wide, and owing to the size of the tunnds the quantity of ore
got out in this preliminary stage is by no means small. When
the bed has been divided up in this way, the work of removing the
pillars begins. As a rule, the attack begins on pillars situated
near the ^undary, so that whilst the first cai'ving out proceeded
towards the boundary, the removal goes on in the opposite direction
— viz,., towards the shaft. A place or drift a 6 is worked across the
pillar for a width of 2 to 4.
Pia. 363. yards, and then, startiiig
from the drift a b, the rect-
angle beyond it is removed
by drivages, called lifta,
sometimes two in number,
sometimes three, as shown
in the figure and marked
I, 2 and 3. It may be
necessary in some cases to
leave a little of the pjllar,
in order to kec^ out the
fallen rubbish beyond and
to prevent a too sudden taU
of roof. According to circnm-
stances, it may be a comer
of the pillar that Is left, or a narrow atrip on one side. The
working place is timbered during the removal of the ironstone,
and when all has been taken out the timber is withdrawn and
the roof allowed to fall. While the lifts 1, z, 3, are being worked
away, another place c dia being driven across the pillar, which
is a preparation for another set of lifts 4, 5, 6 ; lastly, lifts 7,
S, 9 are worked away, and with the exception of occasional small
comers or strips, the removal of the pillar ie complete, and its
place is taken by fallen rubbish. The ironstone is got by boring
and blasting ; the holee are bored by hand or by machine, and
gunpowder is the explosive mostly used. The jumper employed and
the three forms of mechanical augers have already been described.
Varietiee of this method of pillar working naturally occur, but
they all come back to this main principle, when the bed is of a
thickness which enables it to be dealt with in one operation.
A s another example I will take a bed of alluvial tin ore, to which
I have already alluded in speaking of the sinking of a shaft
through mud near Falmouth (p. 268).
The bed of stanniferous gravel varied in thickness from 3
inches to 7 feet, but as a rule it was not thick enough for men to
stand upright when at work ; the maximum width was 100 yards.
It was reached by a shaft D sunk through the mud of the tidal
creek, and also by a shaft C and level AA in the hard slate
(Figs. 363 and 364). Main levels ££ were driven in the gravel
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EXPLOITATION
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3i8 ORE AND STONE- MI NINO.
bed 20 fathoma apart, and air levels GO, all abx)nglf timbered.
Cross or stripping levels HH, 14 feet apart, were pushed out
from one air level to the other, and the gravel was removed
for a distance of 7 feet on each side, as »hown by the shading J.
The mud forming the roof was allowed to fal^ and fill up the
emptj* spacea. The gravel was wheeled in barrows to the main
levels EE, and conveyed by a railway to one of the paaees FF,
which led to large bins, whence it could be drawn off into waggons
in the main rock-level AA, and sent to the shaft.
Drift mining, or the working of auriferous alluvial gravel, is
carried on in a similar manner. Old ri^er beds which carry gold
are common in California, and especially in Sierra and Placer
Counties. These beds once occupied the lowest ground of the
district, and became covered over by true lava flows, volcanic
Hsh and mud, sometimes also by the deposition of pipeclay and
intusoriftl earth. The streams were diverted and cut themselves
new channels, which in process of time were so much deepened
as to tie many hundred feet below the level of the old buned
auriferous beds. The width and thickness of the old gold-bearing
alluvia vary greatly, as might be expected from observing the
bed of a river at the present day, and the gold is not uniformly
distributed in the gmvel. The total thickness of the gold-
bearing gravel may amount to ss much as 600 feet. In drift-
mining the workings are confined to the "pay-lead," usually the
very bottom of the channel, varying from 100 to 150 feet in width
on an average.* Where there is a rich gravel with $5 to $8 per
cubic yard, the leads may be only 50 to 75 feet wide; where
gravel with $3 to $4 is being mined, they are often 300 feet to
400 feet wide.
By tracing the junction of the underlying slate and the
volcanic capping (Fig. 365!), an idea is obtained of the run of the
ancient valley, and arrangements are made for reaching the old
river-bed, eithw by an adit driven into the hillside, or by a shaft
sunk from the top. Working by shafts entails the expense of
winding and pumping, and adits are therefore preferred. In
fixing a position for the adit, care is taken to start it so that it
will come in a little below the level of the gold-bearing gravel,
and so that it will afford suSLcient tip- room for the waste material.
The adit of the Foi'eet Hill Divide Company, Placer County, is 600
yards long, some others are nearly a mile in length before getting
underneath the old channel. When the goal baa thus been attained,
a level is driven in the general direction of the "lead," or, roughly
speaking, at right angles to the first part of the adit ; the whole
of this work is carried on in the slate or " bed-rock," in order
■ Hanunond, "The Andferoas Omvels of California," Cali/orilia State
Miaiof) Bureau, Mnth Anaaai Beporl of the Stale Mincralogirt, Sacramento,
+ i6uJ.,piate6.
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EXPLOITATION. 319
to save the ooet of timbering and repairs, which would be
ooneidarable in the gravel itaelt. Rises (upraieea, U.S.A.) are
pat up into the gravel bed, and, after a preliminary division into
Kgp fiomr cuANNCL
,£ dohaoo mm>m
blocks by a se ee of cross dn ages he bed is worked away. The
gravel ia whee ed to the nses (peuaea chutet, U.S.A.) leading to
the main tunn 1 and thence drops into waggons which are drawn
out by horses to the surface
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320 ORE AND STONE MINING.
It is reckoned in Placer County, California," that, in the auae
of a mine producing 250 tons (or carloads) of gravel a day, the
total cost of getting, tramming, washing and agency is about
fi.io, or 43. 6d., per ton. The yield in this region varies from
(i to $10 per ton (carload,) and may be taken at $2. 50 or 10s.
per ton on on average.
The method of working by temporary pillars is not confined to
beds of Rmall or medium thickness.
The lead-bearing sandstone at Mechemich fumiahes a good
example of what can be done in a rock which, though far
from being hard, will nevertheless allow large excavations to
be made without any timber. As haa been already mentioned,
the bed of sandstone is sometimes as much aa 100 feet thick.
Drivages are made in the bottom part of the bed, about 2 m.
high by 2 m. wide, and these are followed by a series of cross
drivages, dividing the bed up into a number of square pillars,
6 m. by 6 m., or 8 m. by 8 m., resembling the squares of a
chess-board. Then, beginning at the outer part of the boun-
dary of the sett, the miners proceed to remove the whole of the
sandstone from the floor to the roof, and at last let the roof of
conglomerate fall in. Ae a rule they convert the space covered
by four adjacent pillars into one chamber. This is done by
cutting round each of the four pjllafs and gradually reducing it
in size, until at last there is an open space where the four pillars
stood, Shy a square 22 to 24 yards (zo to 22 m.) od the side, the
height still being the same as that of the original drivages — >.«.,
2 metres. Standing upon the broken rock, the men now attack the
roof, which they can often get away in layers of about 5 feet in
thickness, by cutting a big groove round the periphery of the
chamber and often putting in a suitable blast. The central part
will then fall in one mass breaking up as it strikes the ground.
A second layer is taken off and the chamber again heightened
5 feet. While this work is going on the roof is sounded by being
struck with a long pole. The miners leam by the sound given oat
whether the rock ia firm or not, and regulate their work
accordingly. They work upwards till they reach the conglomer-
ate, and luiving cleared out all the ore allow the roof to foil in.
It is important that the roof should fall in, because, as long aa
it remaiuR, it throws its weight upon the other adjacent pillars ;
but when it has come down, the pillara have only to support the
weight of the strata inmiediately above them. In the direction
of the dip, the chambers are sometimes made larger, and six pillars
are taken instead of four. With a very strong roof the chambers
may even cover an area of 109 yards by 43 yards (100 m. by 40 m.),
At Mechemich the workings are arranged so that the chamber
remains open until the last moment, the roof not falling in till
* "BemD&niiiactaeUitlli^angen von der ParUeTWeltaDsteUnng," 18S9,
B. a. i. Zeitung, 1890, p. 314.
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EXPLOITATION. 331
the completion of theproceesof ezcamtioD. Thesulphur Beams of
Sicily are wrought d^ereDtly.* The thick beds are pierced by
networks of tunnels supeniosed one above the other, and the
workings are allowed to fall in. After a time, when the collapee
is complete, the miners make drirages in the mass of crushed and
broken pillars, and so reap a second harvest.
The detftils of the mode of procedure are as follows : When the
dip of the beds is less than 30*, one set of tunnels is driven along
the strike and another set tdong the line of dip. The tunnels are
made 8 to 13 feet (3.5 to 4m.)wide. Those aloug the strike are
8 to 13 feet apart, and those along the dip 10 to 16 feet apart,
leaving rectaDgular pillars between them. If the dip exceeds
45°, tunnels as before are driven along the strike, and these are
intersected by horizontal cross tunnels running from the roof to
the floor of the deposit. The height and width of these tunnels
do not as a rule exceed 10 feet (3 m.). If the bed is thick the
tunnels are traced out in superposed planes, leaving a solid slice
of ground S to 10 feet (2.5 to 3 m.) thick between auy two
successive networks of drivagee.
The first part of the process is now complete, and it is followed
by the thinning of the pillars. Begiuniog near the boundary of
the mine, a tunnel is driven through a pillar, or two tunnels are
driven if it is a hig one. The sides of the tunnels are cut away
gradually, until at last the weight of the superincumbent rock
breaks down what remains of the pillar; sometimes shots are
put in to effect or hasten the fall. As much sulphur rock as
possible is taken out, and the next pillar is treated in the same
way, and so on, always proceeding from the boundaiy towards
the shaft.
This method of working has been the cause of the worst accidents
and of the majority of the fires, especially when the stratum is
thick, and several sets of tunnels have been driven one above the
other. In some parts of the Colle Croce mines, Lercara, there
have been as many aa ten working horizons one above the other,
each horiEon, or slice, being 16 feet (5 m.) thick, and the bed itself
164 feet (50 m.). Sometimes mines of this kind have " caved in"
of themselves ; in other cases the general breaking up and crushing
together has been produced intentionally by bringing down some
of ttie lowest pillars by a few shots. During this crush the heat
produced by the friction of great masses of rock falling against
one another is sufficient to make the sulphur take fire. The mine
is then closed, and the fire eventually dies out for want of oxygen,
though there are instances of fires going on burning for more
than sixty years. When the fire is supposed to be completely
ippo di
lamele
nd 1888, Floreoce,
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322 ORE AND STONE-MINING.
extinguished, work is begun in the broken mass, by driving a
seri«e of tunnels, along much the same lines as those made
originally in the virgin bed. The tunnels are supported by walling
and timber. A Bimilar network is then made at a level iS feet
(5.50 m.) above, and in some instances there are three such setsof
levels in " the broken " one above the other. The tunnels of
the lowest horizon are widened out, and by means of suitable shots
the whole mass of broken rock is made to fall again, aud of course
the tunnels disappear. This process of making a network of levels
at two or three horizons is repeated, and the "caving-in" is
brought about again until the sulphur-bearing rock is exhausted,
or BO much barren stuff from the roof is mixed with it as to
make the work unprofitable.
The crushes themselves have not generally been accompanied by
accidents, but work in the broken ground has been very fataL
For working these deposits, and especially the thick ones, a
filling-up method is preferable, and the " gineei," or residues from
the treatment of the sulphur-rock in kilns, are ready at hand as
the moat convenient material for the purpose.
The fiUing'Up method enables the sulphur bed to be worked
away completely, whereas with the method of networks of drivages
foUowed by falls, fully one-fifth or even one-fourth of the mineral
is lost. Besides, there are fires and subsideaces of the ground
causing fissures which let water in, and therefore producing more
danger to the men and also to the adjoining mines.
The Italian Inspectors of Mines are of opinion that poor
beds, which could not be wrought profitably by the filling-up pro-
cess, may in certain exceptional cases be worked by the old method,
because the firmness of the rock increases as the percentage of
sulphur diminishes. However, they limit the number of super-
posed working floors to three, and stipulate that an upper floor
shall be entirely worked out before a lower one is taken away.
It is estimated that in the year 1889* only 43 per cent, of the
sulphur produced in Sicily came from virgin ground, and that all
the rest was obtained from drivings among broken piUars and
workings that had " caved in."
B. Ijongwall. — Having discussed the various ways of work-
ing a bed by permanent or temporary pillars, we now come to
the so-called longwall method. In this case there is no pre-
liminary carving out into pillars, but the mineral is worked away
in long faces, whence the name applied to the system.
A typical case is found in the workings for copper shale in
the Mansfeld district, Germany, t
* BivUta del lercizio rninerorto nel iSSg, p. 76.
t This account of the workiiiga of the copper shale ie based upon the
descriptioQ in the pamphlet, "Der KapferBChuderbeisbau und der Hiltteo-
betrieS ztit Veiarbeitnog der gewonnetieD Minem in den beideo Uansfelder
Eieimn der Freuas. ProviuE Saohssn, 1S89," and upon personal obsemtions.
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EXPLOITATION. 313
The bed, aa already mentioned, is usually from 3 to 5 inches
thick, but it makes up for ita cbinness and poverty by its
uniformity of yield, at all events compared with a mineral vein.
It is worked for a distance of 11 miles (18 kil.)a1ongthestrike,
and the present plan of operations consists in having a set of
-shafts for every 2^ miles (4 kil.), that is to say a set of shafts
series for the workings i^ milefz kil.) on each side of it. The
great difficulties encountered in emking shafts through the watery
measures above the copper shale have ted to the adoption of the
system of driving out long crosscuts to intersect the bed on the
floor dde. These crosscuts can be driven with speed by
machine-drills, and various mechanical means are available for
haulage. On the other hand, in spite of the considerable im-
provements which have been introduced into shaft sinking by the
Kind-Chaudron process, much time is required and a very heavy
expenditure of capital. There is also the consideration that if
the shafts were on the roof aide, crosscuts would have to be
driven at the level of the adit in order to get rid of the water.
These crosscuts would sometimes traverse the troublesome
gypseous measures, full of unknown pools, and they would be
above theworked-out bed of copper shale and therefore be subject
to slight sinkings of the ground. Crosscuts in the measures
below the copper shale do not present these difficulties. Of
course it would be possible to Uft the water to the surface and not
discbarge it into the adit. This would entail extra expense for
pumping, and in this pazticular instance there is the further
objection that the water is so salt that it cannot be discharged
without damage into any small brook. It therefore becomes
necessary to conduct it into a river like the Saale, too big to be
swiously aSected by the briny stream from, the mines.
The workings are arranged in a succession of floors taken
exactly 62.7 m. apart. This distance is the equivalent of 30
German fatboms, and is 68J yards. To save expense, crosscuts
are put out from the shaft at every second floor, that is to say,
th^ are vertically 125.4 metres one below the other. I>rivage8
along the strike are pushed out on each aide of the crosscut,
and by putting up "rises" each level is brought into com-
munication with the one above. Intermediate tunnels are then
driven along the shale from a point midway between the two
crosscuts, and the bed is now traversed by levels along the
strike, at intervals of 62.7 metres vertically, which constitute the
main working roadways. As the dip is about 5° or 6°, the distance
from one main roadway to the next is as much as 600 to Soo
yards, and constitutes a long working face or "longwaJl." In
Fig. 366, AB represents a main level, and CD the next one
below it. £ F is the working face, which is cut away gradually
till it beoomee E' F, and then E" F', and so on.
This working face is occupied by a string of miners, in fact as
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324 ORE AND STONE MINING.
many are employed as the space will accommodate. The workman
lies upoD his left side, reposing upon a shoulder- board and a leg-
board. The lattbr is strapped to the thigh, but the former is free,
and is shifted as required. The work comprises the following suc-
cessive operations— -( I ) Holing with the pick; {2) wedging down
the copper shale ; (3) blasting down the roof; (4) stowing the
deads. The holing is done in the lowest part of the bed of
copper ore, along the hard and smooth floor. Enough of the roof
is taken down to give the miner just room enough to do his work.
It is best to have as much as 23 inches (58 cm.), but if there is a
convenient smooth plane of bedding for forming the roof at a
height of 18^ inches (47 cm.) no more is taken down; indeed, in
some exceptional cases the height is only 15^ inches {40 cm.).
FiQ. 366.
|i \ — r— ^
The barren rock serves as material for stowing or ijlling up, and
Bs the quantity is more than sufficient for this purpose, some of it
has to be drawn up to the surface.
It is necessary to have roads for taking away the ore from
the face, and they are formed by reserving passages in the
stowing and by blasting down the roof, so as to give suffi-
cient height. These divisional roads are shown by the letters
a b,c d,e/, &c. The interval between them varies from 50
to 120 yards; and in all cases there are diagonal branch roads
leading from the railroad towards the face, which is finally
reached by the so-called " Fahrten." Thty are low passages in
the stowing, along which the ore is dragged by boys in little carts.
The diagonal roads, however, are made 5 feet high by blasting
down the roof. Owing to the small scale of the diagram it is
impoesible to show all the branch roads connecting the working
face with the levels running along the strike. The direction
given to the working face is a matter of importance, for it
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EXPLOITATION. 3^5
enables the amouot of pressure coming upon the rock to be ^tried.
The pressure is felt most when the face is parallel to the strike
and the working carried up to the rise ; it is felt least when the
face is pandlel to the strike and the work is proceeding down-
wards. If the face runs in a direction parallel to the line of dip,
the pressure is intermediate in amount. Therefore by regulating
the line of the face, the mining authorities have it in their power
to cause what amount of pressure they think most desirable for
the work. As a rule the line chosen for the working face lies
somewhere between the line of strike and the line of greatest
In new ground in the deeper workings, holing with the pick
is a very laborious operation, and has on that account been given
up ; in such places the shale is got by blasting. After the lapse
of three-quartera of a year or a year and a half, when a large area
has been worked away and the roof begins to subside upon the
stowing, pressure is felt on the working face and the hohng be-
comes much easier. In order to bring about this state of atlairs
as soon as possible, Jager drills worked by compressed air have
been employed in gettiug the ore.
The Maosfeld longwall has the peculiarity that more deads
are produced than can be stowed away in the excavations ; these
are therefore packed very full and the amount of subsidence is
not gi'eat.
In some other varieties of the longwall method there is no
stowing at all and the roof is allowed to fall in, or the amount
of rubbish produced by the seam is insufficient to fill up the empty
spaces. There is also a diversity of practice with regard to the
direction in which the longwall face is carried, sometimes the
seam is worked by longwall outwards — that is to say, the face
is carried from the neighbourhood of the phaft towards the
boundary of the property, in others it is carried " homewards"
from the boundary towai'ds the shaft.
X, VlilNS, — In the case of a vein, an e:cploratory pit is
often sunk upon it for 20 or 30 fathoms, and, if the indica-
tions found in driving out levels warrant further prosecu-
tion of the mine, a first working shaft is put down to
intersect the lode at a depth of 100 fathoms or more from the
surface, Ci-osscuts are then driven out at intervals of 10, 15,
or 20 fathoms to reach the lode as shown in Fig. 367, which
represents a section at right angles to the line of strike.
Sometimes the main shafts are cai'ried down all the way along
the dip of the vein, though perpendicular shafts have the
advantage of being better suited for quick winding and
cheap pumping, to say nothing of the rapid ascent and descent
of the miners in cages. If an inclined shaft appears to be
advisable, great care should be taken to sink it in a straight
line. The worst shafts are the crooked ones so conunon in
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326 ORE AND STONE-MINING.
Cornwall, vertical perhaps for the first hundred fathoms until th»
lode is struck, and then carried downwards along its varying
dip.
Whatever Hnd of shaft is adopted, levels are driven out along
the strike of the Iode,a8 shown in the longitudinal section (Fig. 368),
in the hope of meeting with valuable ore-bodies such as are
represented by the stippled portions of the figure. For the
purpose of afibrding ventilation, and still further exploring the
ground and working it, intermediate shafts, called wiTtzea
(Cornwall), or eumpa (North Wales), are sunk in the lode from
one level to the other. In some cases the communicating passage
is excavated upwards, or, in other words, the miner " puts up a
Pro. 367. Fig. 368.
rise." When the communication is complete, there is no differ-
ence whatever between a rise and a winze.
On looking at the longitudinal section (Fig. 368), which may be
regarded as representing a common state of thuigs, it will at once
be remarked that only certain parts of the vein are valuable.
When dealing with a bed or seam, we constantly find that the
whole area covered by it can be worked away profitably. With
a lode this is the exception, and therefore the problem of exploit-
ation is not the same in the two cases. The vein-miuer has to
remove portions of a sheet-like deposit usually dipping at a high
angle, and the bed-miner to excavate the whole of a sheet-like
deposit lying frequently nearly horizontal. The unworked por-
tions of the lode serve to support the hanging wall, and form in.
this way the equivalent of irregular pillars.
The actual mode of removing the valuable part of the lode
itself depends a great deal upon circumstances — viz., its width,.
the nature of its contents, and that of the walls or enclosing
rock ; but the methods of working may generally be brought
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EXPLOITATION.
3*7
under one of two heads — viz., underhand atoping or overhand
stoping. The word " stope " is equivalent to step, and the term
" stoping " means working away any deposit in a aeries of steps.
Underhand or bottom stopes are workings arranged like the
steps of a staircase seen from above, whilst overhand or back
stopes are like similar steps seen from underneath. Both
methods have their advantages and disadvantages, and both are
largely used.
We will first take underhand stoping, as this is the older
Pio. 37%
FIG. 369.
m//mm^:zm/,
Fia. 371.
//////////////////
method. In the old days the miner began in the floor of the level
(Fig. 369), and sank down a few feet, removing the pari i ; he
followed with z, 3, 4, be., until the excavation finally presented
theappearanceshownin J^^. 370. Any valueless rock or mineral
was deposited upon platforms of timber (stuUs), and the ore was
drawn up into the level by a windlass. One great disadvaiitage
of this method was the cost of winding up the ore and water by
hand labour. At the present day the disadvantage would not he
so great, because power is so
easily conveyed to underground
windies by compressed air or elec-
tricity. There always remans,
however, the necessity of pro-
viding much timber for the stuUs,
if there is a large quantity of
worthless stuff in the vein, or if
tbesides are weak. The advan-
tages are that ore can be worked
away as soon as a level is driven,
that the men are always boring downwards, and, lastly, that the
ore can be carefully picked after it is broken, without fear of any
valuable particles being lost.
A more economical method of working by underhand stopee,
and one largely employed in Cornwall at the present day, conasts
in reserving any attajsk upon the ore-ground until a lower level
has been driven. A connection is then made between the two
levels by sinking a winze from the upper one, or by putting up
a rise from the lower one.
The work of stoping is commenced from the two upper ends of
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))8 ORE AND STONE-MINING.
Fio, 37*.
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EXPLOITATION. 329
tbia intermediate shaft, and the lode is removed in a succession
of Btepb, the workings assuming the appearance exhibited in Fig.
371. The steps are gener- j.^^
ally made steep, so that
the ore tas-j readily roll
down into the winze, and
so that the boreholes may
do better execution : but
these steep stopes ore
dangerous if a man hap-
fjns to slip and fall. The
uge open chasms left by
the removal of a wide lode
in this way are also a
source of danger, for
there is always a risk of
falls of rock, and from
places which cannot easily
be examined.
Rgs. 372 and 373 ex-
plain the general arrange-
ments for working Dol-
coatb, the largest tin mine
in Cornwall. The lode,
after producing copper
ores for a considerable
depth, changed its char-
acter and became rich in
tin. The workings for tin
are confined almost en-
tirely to the granite. The
section (Fig. 373) shows
that the main shaft of the
mine is at first vertical and then carried down on the dip of the
lode. The mine is now coneider-
ablydeeper than indicated in the
figures, but the method of work-
ing remains the same.
The process of overhand
stoping ia precisely the reverse
of that which has been des-
cribed : the work is commenced
from a rise (Fig. 374, A}, or
-P ^^__^___ better, from the two ends of a
'/////<'/////. ///////// winze (Fig. 374, E). As soon
as the men have excavated a
sufficient height of the level, they put in strong pieces of timber
from wall to wall {etempda, eluU-pUees), and cover these cross-
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330 ORE AND STONE-MINIUa.
pieces with boards or poles, and throw down the rubbieli upon
the platform (ttvU, bunnittg) thus formed. In the midst of the
rubbish, chimney-like openings {milh, jKueea) are reserved, lined
with bcmrds or dry wBlUng, and closed at the bottom with Bhoots
provided with doors. The ore is thrown into these passes, which
Fio. 375. Fio. 376.
\\\\\\\.\\\\\\\\\\\x\
\\\\\\\\\\\\\\\\\\\
are tapped when necessary. The ore falls into the tram-waggon
placed ready to receive it.
Fig. 375 is a transverse section, showing the rubbish resting
on the stults. This may be called the typical mode of stoping,
when the lode affords enough rubbish for the men to stand on,
and to keep them close to the rock they are attacking. Very
often such is not the case, and the whole of the lode has to be sent
up to the surface for ti-eatment. If
Fia. 377. the walls are firm, a stull is put in,
and a sufficient hcnp of broken ore is
left upon it to give the men good
standing ground ; the excess is thrown
over the ends of the stull, or the great
heap is tapped by cutting a hole in
the supporting platform and letting
a quantity of ore run down into the
level.
Another method consists in putting
in temporary stages or platforms
upon which the men stand to do their
work, whilst the excavation is left as
an open space (Fig. 376). This mode
of working is incompatible with weak
walls. If a lode does not aSbrd rubbish enough for completely
filling up the excavated space, or if it is too narrow for the men
to do their work comfortably, one of the walls may be cut into and
blasted down (Fig- 377), in order to give the men a firm bed of
rubbish to stand on while at work, and to prevent any chance of a
collapse of the mine. In certain special cases rubbish is sent down
from the surface to fill up the excavations.
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EXPLOITATION. 331
The adrantages of overhand atoping are— that the miner is
aasieted by gravity in his work, that no ore or rock has to be
drawn up by hand labour, and that less timber is required. Ou
the other hand, the miner is always menaced by falls of the roof
of hb working place ; but as he is close by, he can constantly test
the solidity of the roof and sides by sounding them with his
sledge. If the rock rings clearly he feels safe, but if it emits
a dull hoQow sound he knows that it must be taken down at
once, or be supported in some way. A last disadvantage of
overhand compu^ with underhand stopee, is the chance of
valuable partides of ore being lost in the rubbish ; but this loss
can be prevented by laying down planks or sheets of iron while
the lode is being broken down.
When very wide lodes have to be worked, recourse is often
had to a filling-up method, and, indeed, such a method becomee
imperative if the sides are weak. The great lode at the famous
Van Mine, in Montgomeryshire, once the premier lead mine
of the United Kingdom, had
to be worked in this fastiion, ^'<>- 37S-
and as the work was carried
out very carefully and sys-
tematically, no better example
of the method can be chosen.
The lode is evidently a fis-
sure vein as it cuts across the
planes of bedding and of
cleavage of the adjacent slate
rock. It is composed of three
parts : the Jlucan or soft lode
B (Fig. 378), the bastard lode
C, and the regular lode E.
The fiucan consists of clay
and soft broken slate. The
bastard lode is a mass of slate rock, 4 or 5 fathoms wide, between
the flucan and the regular lode ; it is much softer than the true
couniry, and, though intersected by numerous small strings of
galena, is rarely rich enough to be worked. The regular lodeconaists
of masses of slate traversed by veins of galena, or it is a breccia of
fragments of slate cemented together by quartz, galena and blende.
The regular lode was at times as much as 48 feet (14.60 m.) wide,
and if the excavation formed by the removal of such a quantity of
rock had been left open, the banging wall would speedily have
fallen in, and indeed even during the progress of the work the
men would have been exposed to very great danger. A filling-up
method was therefore adopted, and as soon as the ore had been
removed the open spaces were packed with rubbish.
Crosscuts were driven out at vertical intervals of about 1 5 fathoms
to i-each thejluoan B, which was chosen for driving a preliminary
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33i ORE AND STONE-MINING.
east and west level on account of ita softness. This prelimiiiary
level enabled the regular lode to be reached veiy quickly in several
places by short crosscuts, from which the first level in the lode
was pushed out east and west.
The next process consisted in stripping away both sides of the
level, as far as the footwall on the north and the bastard lode
on the south, unless the latter happened to be productive, in
which case it likewise was excavated. This left a space about
7 feet high, which was at once filled with deads, save a
working level reserved ia the middle, which was properly secured
with timber. Endeavours were always made to keep this level as
straight as possible, so as to facilitate the tramming. The letter
H in Fig. 378 represents this working level. Upon its com-
pletion the preliminary level became superlluous ; the timber
was drawn out and allowed to crush together, as shown in the
lower part of the figure.
In thu meantime, starting from the level above, winzes were
sunk, 20 or 30 fathoms apart, in the flucan or in the lode
itself, if the fiucan happened to be too far away from the produc-
tive part. The winzes served not only for ventilation, but also
as shoots for the rubbish used in filling up ; they were called
poMts, I (Fig. 37S). Thay were carefully timbered and divided
into two compartments : one was used as a passage for the rub-
bish, the other was provided with ladders, and formed a foot-
way, besides affording access to the other compartment, in case
it became choked wit^ the waste rock shot down it.
As soon as arrangements for supplying the deads were complete,
stoping was begun. The height taken off in each stope varied,
according to the firmness of the lode, from 2 to 6 feet, and when
the ore was removed the excavation wa^ packed with i-ubbish
(D) drawn down from the nearest pass, such as I (Fig. 378),
and wheeled in a barrow to the place where it was wanted. As
the passes were made at close intervals, the amount of wheeling
was very little. The broken ore was thrown down into a past or
mill, K, whence it could be drawn off at pleasure into a waggon.
The ore-passes were of the same size as the winzes sunk for
letting down the rubbish, and were timbered and divided into
two compartments in the same way.
The lode itself furnished enough rubbish to fill up about one-
third of the excavation ; waste rock was likewise obtainable from
workings in dead ground, such as crosscuts, and the preliminary
or permanent levels ; and finally slate was quarried at the surface,
shot down special shafts, and trammed through a level such as P,
and a crosscut N and level H, to any special pass where it was
required. To prevent any loss of ore among the loose stones used
for filling up (aloicing), it was usual to spread over the top of the
rubbish a layer of soft flucan for a depth of a few inches, and when
the lode had been stuped away to the required height, this floor
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EXPLOITATION. 33j
was shovelled into the ore-passes and went to the dressing floor
with the rest of the stuff. It was found cheaper and better to
drees a few extra tons of stuff than to pay for laying down boards
or sheets of iron to catch the fioe ore.
Slice after slice wm taken off in this way, and the long working
face formed by the roof of the stopes corresponded in some measure
to a longwall face in bed mining. On arriving within 12 feet of'
the old workings abore, packed with rubbish, it was unadvisable
to m&ke openings of the full width of the lode, and the ore was got
by crosscuts. A level was driven along the strike in the middleof
the lode, or on one side if more convenient ; crosscuts, from 5 to 8
feet wide, were started from each side of it, and driven north and
south to the footwall and hanging wall respectively, the ground
being supported by strong props of timber. The lode standing on
the sides of the crosscut was then removed by a series of cross
drivages similar to the original crosscut, only, as one side was free,
the work was much less expensive, costing abont ^£4 per fathom
instead of ^10. The empty spaces were packed witn waste to
the top, and as much of the timber was drawn away as could be
removed with safety.
When the lower half of the 13-feet slice had been taken away
in this fashion by a series of short contiguous cross drivages,
another level was driven along the strike above the old one which
had been filled with rubbish. Crosscuts similar to the ones below
were driven, save that spilling had to be resorted to, as the roof
was formed of the deads of the earlier workings. Whilst this
work was going on, the miners could recover any pieces of timber
which had been left in the midst of the rubbish used for stowing
the lower half of the slice. The legs or/orka were always put in
with the large end uppermost, and could be drawn up by putting a
chain round the top and applying a lever. As soon as ^e upper
half of the i z-feet slice had been taken off by these cross drivages,
the working level H above it was filled up and abandoned.
The block of lode 15 fathoms high waa thus removed entirely,
and its place filled by rubbish ; consequently there was no danger
of the walls falling in and of the mine collapsing. No high openings
were made during the progress of the work, so the roof and sides
could be sounded and examined without scaffolding ; any loose
pieces could be token down at once, and there was little fear of
their falling unawares upon the miners.
Before a block was completely stoped away, the so-called penna-
n«>U level at the bottom bad to be prepared, in order to furnish a
road for conveying deads to the block beneath. Crosscuts, N,
were pushed out from the level H, at intervals of 20 or 30
fotboms, to a distance (^ 10 fathoms beyond the flucan, and "ends"
were driven east and west till they met and formed a continuous
gallery, P. Bails were laid and the road was ready for use.
Several men were kept constantly employed at a quarry
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334
ORE AND STONE-MINING.
adjoining the mine for obtaining slat«, which was tnimined to
and shot down one of the two special rubbish shafts. Theee could
be tapped at the adit, and the supplies were conveyed by tram-
roadf) and other special shafts, used as Kfaoots, to the places where
they were required. Excepting the first two rubbish shafts from
the surface, no shoots were made more than 15 fathoms deep,
because it was found by experience that the timber was broken up
very quickly by the fall of the stuff when they were deeper. The
bottom of one shoot was always near the mouth of the next, so
that the rubbish never had to be trammed far ; and in some
instances the shoots were so near that, by fixing a few planks
in a sloping direction, the waste rock ran directly from one to
the other.
I have etitered somewhat into detail in this case, because wide
lodes with weak walls have often given much trouble, when the
attempt has been made to work them with the use of timber
Fig. 379.
Fig. 380.
.supports. The amount of timber required at the Van Mine waa
small, and many of the pieces were used over and over again.
Another advantage in this particular case was the certainty that
no ore was lost or left behind ; for although money was sometimes
spent in breaking down poor partsof the lode to make sur« of not
missing any lead ore, the barren rock could be utilised for filling,
instead of drawing supplies from quarries at the surface.
At the Van Mine the lode waa firm enough to allow the whole
width to stand without supports during the time a stope was carried
along, except in the case of the two last slices at the top of a block.
These, as we have seen, were taken ofi' by a succession of conti-
guous croescuts. When a lode is wide and too weak to stand open
with safety for its whole width, the crosscut method may be
applied from the beginning, instead of confining it to the last
slices.
The method is illustrated by Figs. 379 and 380. The lode is
removed in successive horizontal slices, ABC D E, beginning
at the bottom, and for each slice a level, L, is driven, either wholly
in the lode, or partly or entirely in the country ; from this level,
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EXPLOITATION. 335
crosBCuts are put out 6 or 8 feet wide, as shown in the plan
(Fig. 3S0). These are regularly timbered, according to the necessi-
ties of the case, and when No. i is completed, No. 2 is hegun, and
the rubbish from No. 3 thrown into the empty space of No. i cross-
cut. If the quantity is insufficient, deads are brought in from the
surface or from exploratory workings in worthless rock in the
neighbourhood. Sometimes the crosscuts are not driven side by
side, but 1 and 5 may be driven first, leaving 2, 3, and 4 as a solid
pillar ; then 3 is worked away, and finally 2 and 4 between the
timber and rubbish on each side. The greater part of the timber
can be recovered when the next slice above is token off, as the
props are put in with their small ends dotvnwards, and can be
drawn up with a lever. M (Fig. 379) is a level reserved in the
deads for traffic and ventilation. This method of working is
applicable not only to lodes, but also to irregular masses.
The mode of working the soft ore-bodies such as are met with
in the Comstock lode, in the Eureka-Richmond mines, Nevada,
and at Broken Hill in New South Wales,
has been already described in the chapter ^^^- 3Si>
upon timbering. The excavations are
supported by huge frames of timber, made
l^ adding one " square set " to another as
required, and are finally filled up entirely
with rubbish.
Another method of working a wide lode
is to attack it in slices parallel to the dip,
removing each slice separately, as if it were
a lode of ordinaj-y dimensions, and filling
up with rubbish (Fig. 381).
We have here been supposing that the
whole of the lode is taken away from wall to wait. Other cases
mayarise. Thusat Poxdale mine, in the Isle of llan, we have to
deal with a. vein of lead-bearing rock which is not ore-bearing for
its entire width. The vein runs east and west, and in places is
1 40 feet wide. Levels are driven along the northern and southern
boundaries, and show whether or no there is any payable ground
on these walls; crosscuts put through from time to time further
prove the lode, and sometimes there may be three parallel workable
portions with barren rock between them. Each of these portions,
which will rarely exceed 1 2 feet in width, is then treated as a
separate lode.
The rule at Foxdale (Fig. 3S2) ia to drive the levels 15 fathoms
apart, and to eSect a communication between two adjacent levels
at intervals of 30 fathoms, either hy a rise or a winze. The lode
thus becomes cut up into blocks 15 fathoms deep by 30 fathoms
long, in the direction of the strike. These blocks are worked
away from below upwards in separate " pitches," each 10 fathoms
long, arranged like three steps. The block therefore affords
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336 ORE AND BTONE-MINING.
three pitches, or subordinate blocks. Thus if ABDC represents
a block contained between an upper level AB and a level CD,
15 fathoms below it, and bounded on the two ends hy the
winzes AC and BD, we must first divide it in imagination into
the three parte A£GC, EFHG, and FBDH. The remoral of
each pitch, or third of a block, is confided to a 8eparat« set of
men. The first set begin at the bottom of A£GC, and take off
a slice 6 feet thick, filling up- the vacant space with rubbish;
then they begin a second slice, and go on taking off slice after
slice until they reach the level above.
Work upon the second division — viz., EFOH, is not begun
until the first slice of the adjacent " pitch " has been filled up.
Fig, 382.
0 S 10 15 20 23 30 33 40 44 METRES
und in the same way Uock FBDH is not attacked nntit at
least one slice of EFHG has been worked away. At some given
time the workings will have assumed the form shown in the
figure.
If, as is often the case, there is a hard and a soft part in the
lode, the work in the overhand stopes goes on as follows : Start-
ing froin a winze, the miners push on a drivage in the soft part,
and timber it up with a cap resting upon the hard side and
upon one leg (t'ig. 383). This renders the working of the hard
part very much less expensive, for it can be got by shots which
take full effect in such large openings. Before blasting out the
side, the caps are supported by a longitudinal carrier resting
upon a few upright props in the manner shown in figure 384.
All the rock is picked in the mine, and any waste is used for
filling up. At last the whole excavation that has been niade
is packed, with the exception of a passage, iS inches high, below
the caps, along which the men can creep if necessary. A fioor
of planks is laid down, and servee to make a bed to prevent the
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StaUvfMtn't
L, GiBDita, or bama part of tbe lode ; B. Soft jArt of tba lodo ;
C. Haidwrtofthelode; D.Leg; B. Cap; F. Floor of planka ;
O. LongitadtsAl Oftporouiier; B. Rropi I. Prop; E. FUling
of WMHIOOk.
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338 ORE AND STONE-MINING.
toes of small ore wliec the next stope or slice is taken off. Shoots
or " pnsaes " lined with timber are reeerved in the rubbish ; there
IB generally one at the end of each pitch and one in the middle.
In this way the miner always has one close at hand, and never
need wheel the ore very far. The shoots are furnished with doore
at the bottom, and the ore is drawn off directly into waggons
underneath without any shoveUing.
Care is taken to drive a crosscut from time to time, to prevent
any chance of possible bunches of ore in the sidea being missed.
Waste rock obtained in this way is always useful for filling up.
The Fozdale lode furnishes about enough barren rock to fill up
the excavation, without its beiag necessary to draw suppliee from
the surface.
The timber buried in the rubbish ie not lost, for it caa be
withdrawn when the next slice is taken off. A piece of ^-ioch
iron chain is made fast round the top of the leg, which always
has the small end at the bottom, and the hook of a special lever
is put into a suitable link. The fulcrum of the lever is carried
by an upright bar attached to a square base, and by applying
pressure to the lever the leg is gradimlly pulled up.
Wide Lodes worked with Piilart and Chamben. — The present
method of working the wide veins at the Kio Tinto mines may be
briefly deeoribed as pillar and cbamberwork, with a solid roof and
floor between the working horizons. For the present the pillars
must be looked upon as permanent.
The details of the system are as follows : A vertical shaft is
sunk in the adjacent rock, and crosscuts are driven out to the
lode at intervals of 25 metres (8^ feet); these form the main
working floors or horizons. A main level is carried along the
strike of the lode at each horizon, and, by sinking from one level
and rising from the one below, a vertical intermediate shaft is
formed, effecting a communication between them. All this
preliminary work is done by the aid of rock drills. An inter-
mediate level is next pushed out along the strike by hand labour
midway between the two main lev^; the vein may then be
r^arded in imagination as divided into a series of horizontal
slices, each iz^ metres in thickness, as shown by the dotted lines,
AB, CD, EF, Ac. in the section (Fig. 33?). The formation of
pillars now begins : the lower part of eacn slice is cut up by a
network of drivages 3 to 3^ metres wide, and 3 to 3I metres high,
at right angles to one another, leaving pUlan 6| to 7 metres
square (Fig. 386). A very large amount of ore is produced
in this way. The next sta^e in the process of mining is
heightening and widening the chambers; in ordinaiy hard
pyrites the pillars can be thinned down until they measure Only
3 metres by 3 metres, and the chambers caji be carried to a
height of g to 10 metres. Where the ground is weak more has
to be left for support. The two plans (^E^. 386 and 387) show the
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EXPLOITATION.
339
ioitial size and the final size of the pillars, whilst the section
(Fig. 385) furthei- explains the progi^eea of the work. At the 225-
metres horizon there are preliminary levels 3 metres wide and
pillars of 7 metres ; at the 3i2j-Djetr6a horizon the enlargement
of the chambers has begun ; at the zoo-metres level the process
has been carried further, and at the two upper horizons it has
been completed, the pillars being reduced to 3 metres. The solid
slice of ore, 2 ^ to 3! metres thick between two storeys, remains for
the present untouched, and forms with the small pillars a reserve
stock which can be removed at some future time. Great care ia
taken to arrange the pillars vertically one under the other with
Pio. 38s.
^ ^ Via. 386.
■"i I. A i A { . \\
_J i' A i. ] L_J i
their centre lines coinciding exactly. When operations have
been finished, the workings have the appearance of very high
columns supporting huge arches. It must not be supposed U^t
the honeycombed part of the vein formed by the deserted chambers
is entirely unproductive; a very large surface of ore is left
exposed to the action of air and moisture, oxidation goes ou,
copper and iron sulphates are produced, and during the rainy
season water trickling down the sides of the caverns carries them
in solution to the bottom of the mine. The coppery water
pumped up from underground is led into precipitation pits,
gjinilar to those employed for treating the cupreous solutions
obtained more ra|udly from the ore burnt at the surface.
At the present time the quantity of ore in sight is so great
that it is not necessary to devise schemes for removing the
reserves; but the work might be accomplished by a fiUing-up
prooees, beginning at the bottom. The pillars and the intervening
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S4°
ORE AND STONE-MINING.
solid floors i^ ore could be removed as lunizoatal slices, fol-
lowed bj a filliDg up ^th rubbish let down from tlie anrfaoe.
In this manner the workmen would alw&ys be standing on firm
ground within euy reach of the ore.
3. HAS8BS. — The methods of working mosses may be dasEdfied
thus:
(a) Method b7 ohambers withgat flUinK up.
<(} Method by Ikoriiontal elicea, taksn hi dascendiiiK ordar, allowing
the tnrfuie to sink down.
(c) Mel^od by horitoct&l ilices, takea In ascending older, with
oomplete filling np.
fa) Thefirst of the three methods is applicable when the enclosing
is strong enough to allow chambers to be worked out without
rock
A. " ^r^llmestone " ; B. LimeEtone,tIke BO-callAd " CiBBBe meBBnrea ";
C, CbamberB or caTerns iaft by the excavation of the ore ;
D. Brown htematJte; E. Top or Whitehead limestone; F. Band-
stona (Millstone Qrit); O. Main level ; H. Bapportliig pillar
bnilt np of stonea and timber.
dmiger from the roof and sides falling in. As an instance I may
take the so-called "chums" of the Forest of Dean, which are
worked for iron ore. Brown hematite occurs in irregular pockets
in a certain bed of the Mountain Limestone (Fig. 388), which is from
14 to 16 yards thick, and usually dips at a considerable angle. At
the particular mine chosen as an example the dip is 52°, Perpen-
dicular shafts are sunk, and the ore-baaring limestone is reached
by crosscuts at vertical intervals of too to 150 feet. A good main
level is driven along the strike of this bed, and small crosscuts are
put out in order to search for the chums, which have often been
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EXPLOITATION.
341
followed down from the surface to a depth of zoo yards. The
W^loitatioii oonsiatB in removing the soft ore with the pick, and
mpporting the roof with occasional props or rough walla bvdlt with
pieoee of barren rock ; timber and stone may ha used together, aa
•faown in the figure. If the pocket is very steep it is worked like
a mineral vein ; the men stope the ore away overhand, standing
upon platforms of timber erected across the chasm left by wca-kiogs
below.
(6) An ezoeUent example of the second method of working is
(nroiabed by De Beers diamond mine, where a mass of diamond-
Tia. 389.
bearing rock occurs as a huge vertical column, with an. irregular
oval section (Figs. 30 and 31), It was worked for many years aa
an open quarry, but falls of the surrounding rocks {reef) cansed
BO much trouble, as the huge pit increased in depth, that under-
ground mining bad to be adopted.
Tbe system consists in excavating chambers, and then letting
rubbish from the open pit above run in and Sil them up. The
details of the method wul be plain from consulting Figs. 3S9, 390,
and 391, which are copied from the second and third annual
reports of the De Beers Company. The deposit is reached by an
inclined shaft sunk in the surrounding rocks, and main levels
are driven at successive horizons which are from 90 to izo feet
«part vertically. Fig 389 shows these mnin drivages at the Soo-
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OEB AND STONE-MINING,
no. 390.
Fio. 391,
b level ; there are two
principal drivoges parallel
to each other and follow-
ing the direction of the
axis of the rough oval, and
from them cross tunneU
are put out at intervals
of 56 feet, and extended
to the limits of the " blno,"
or, when directed to-
wards each other, tiU
they meet. Another set
of levels is driven at a
depth of 30 feet below
the main tunnels, and a
third set at a further-
depth of 30 feet. The
block of ground between
two main horizons thus
X becomes divided up into a
o series of horizontal slices,
* 30 feet thick, each of
which is cut up by a net-
2 work of tunnels 36 feet
* apart extending to tha
' surrounding rock.
When this rock is
reached, the tuonelB aro
widened out till two adja-
cent working-places meet
as shown in the plan (Fig. 390). The next process is to rite, or work
upwards, antil the " blue " is traversed and the waste fallen rock
Fio. 393.
~v^ Original turfac
T
I
; C. Sand and cUj ;
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EXPLOITATION. 345
ftbove it is met with. This is allowed to nm in and form a heap
upon which the workmen stand, in order to blast down the re-
maining part of the slice of " blue." As this is taken away the
waste rock i^^f) follows. Fig. 391 also shows that the workings
in an upper sUce aro always further advanced than those in a
lower one. Only the main levels ore provided with regular
ttamways. The blue got in the intermediate levels is thrown
Pio. 393-
San.d ic Jrvn Ort ZimttUnt.
down shoots, and so finds its way to the main level, whence it
can be hoisted to the surface.
A somewhat similar mode of working is customary in the iron
mines of North Lancashire, which have to deal with irregular
masses of hematite in the Mountain Limestone (Fig. 393).*
Shafts are sunk at a distance from the deposit, which is reached
by crosscuts at intervals of 10 fathoms vertically. Levels and
cross levels are then driven which bring all parts within easy
reach (Fig. 393). Bises, B, £, are put up from the main flow
■ I am indebted to Hr. J, O. Lawn, A.R.S.H. and De la Beche
Medallist, for bis notes on the method of woiking ; from these, sod from
m; own TecoUections, this deBcriptioD bas been wriiteo.
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344
ORE AST) STONE-MDTING.
or horicon to the next one a.bove, and the deposit is now taken
awa^in slicea or "heights," 9 or to feet thick. A and B of
Fig. 394 represent two adjacent risee. The men starting from
A, pnsh out the drift I, and those from B the drift /, until they
meet, for the sake of rentilation. This air-road il has to be
kept open while work is proceeding in the slice or height in this
district. Branch drifts, 3 and //, are carried forward to the
boundary of the deposit or of the area the men have to work, and
lastly comes the robbing of the ore by a series of drifts, such as
J. 4> Si 6, or ///, 17, V, in the order of the numbers. The
work is thoB carried on towards a rise and not from it.
After the ore is robbed, the roof crushes in, smashing the
timber and forming a safe ceiling for the wakings in the
Fio. 394.
next slice underneath. The surface sinks down in proportion as
the ore is removed, so that in some parts of the district immense
boles exist, giving evidence of the working out of vast bodies of
hnmatite underneath (Fig. 393). As the overlying drift oftra
contains clay, rain water collects in these holes, and it has to be
pumped oat lest it should break through and drown the miners.
The rises are usually made 6 feet by 4 feet 6 inches within the
timbering, which consists of sets of Xorway or Swedish timber
6 or 7 inches square, simply halved at the joints and placed
directly one above the other. Most of the rises are dirided into
two compartments by pieces of 3-iach plank cut to the right
length and wedged in; these are made firm by nailing on to
the rise-timber " listing pieces," strips of wood 3 inches by J
inch, on each side. One of the compartments serves for a iodder-
way, for pulling up timber and for an airway ; the other as a
rec»pta£le for tha ore. The latter is called a "hurry," and is
provided at the bottom with on inclined shoot through which the
ore can be let into waggons or " bogies " at pleasure. Sometimes
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EXPLOITATION, 345
the rise ia made 9 feet by 4 feet 6 inchea, and divided into three
compartmenta — viz., two hurries, and a ladderway between them.
One hurry then serves for ore, and the other for rubbish.
When the men have all but removed one slice or "height," they
take out the timber of the rise on one side, in order to start a new
drift ; it is about 7 feet wide, and is supported 1^ frames, each
miade of a cap or head-tree resting upon two legs or " forks." To
protect the men while working in the forebreast, small planks
(epUea) are driven under one head-tree and over the next, and,
if necessary, along the sides behind the props. The men are not
allowed to advance more than 4 feet beyond their timber. As
soon as the slice above is quite exhausted, they open out at the
other side of their rise, and after putting in a strong covering of
Fia. 395.
timber, they clear all the rise of its lining down to the level at
which they are working. In driving below the old timber and
rubbish, it is necessary to be careful that the supporting frames
are properly put in and kept well forward ; they are often held in
place by naiUng spiles to them, but this is only necessary before
they get the weight from above. It is possible in many cases to
save much of the timber used in lining the drifts which are made
for robbing the ore, but in all cases the roof comes down very
quickly, whether the timber is left in or not.
(c) The lest method — namely, working away the mass by hori-
zontal slices, in ascending order, with complete filling up —
exactly resembles that which is adopted for certain wide veins,
such as the lode at the Yan mine, Montgomeryshire. However,
it may be well to mention, as an example, the great zinc ore
stockwork at Diepenlincben, near Stolberg. The Mountain
limestone is full of cracks and cavities containing blende, which
cannot be worked to advantage without breaking down the whole
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346 ORE AND BTOHE-MINING.
of tlie rock. The limeBtone is ore-bearing over an oval area,
I30 metres long from east to west and 50 from north to south
(130 yards by 54 yards).
This great mass of zino-beariDg rock is Bubdivided for the pur-
pose of working into a series of storeys or floors, each 16 metres
(52^ feet) thick vertically, and a main level is driven along the
major axis of the oval at the bottom of eaoh storey, as shown in
Fig. 396. GroBs-cutfi, 14 metres apart, are driven out north and
south from each main level, and are connected with similar cross-
cuts below by winzes. The block of ground between two main
levels is then taken away in slices, 2 metres thick, in ascending
order. However, with the view of saving the expense of putting
Fio. 396.
in timber to support the deads, which would be necessary if the
main roads had to be kept up in a part of the mine stowed with
rubbish, the fitst two slices — that is to say, the one in which the
levels are driven and the one immediately above it — are left intact
at the ou'teet. Work is started from a winze at a point 2 meties
above the top of the level, and the whole area of the deposit cleared
out for a height of 2 metres ; the excavation is then ^ed up with
deads. The deads are obtained by picking the rock broken down
in the stopes, or from any drivings or sinkings in barren ground,
and also by sending down supplies from the surface. Shoots are
reserved in the stowing for throwing down the ore, which is
drawn off at the bottom when required.
Fig. 396 shows the stoping going on between the 200 and the
2i6~metre6 levels. When the stopes come up to the sole of the
200-metree level, the ore surrounding the network of levels and
that of the overlying slice can be attacked. By this time thia
double slice, 4 metres thick, is somewhat crushed and broken.
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EXPLOITATION. 34?
It would be daogeroos to have the wide workuig-phicee, which
can be excavated without fear iu virgin grouud; therefore,
just as happened in the Van Mine, the two last siloes are
got by a series of small drivings, in which the miners resort to
a proceas of spilling. By applying this process the remainder
of tiie ore is obtained in safety, and the final result is that the
great mass of zinc-beariug rock is replaced by barren material
with the ei^nditure of very httle money for timber.
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CHAPTER VII.
HAULiGK OB TRANSFOBT.
ground bj alutilai meoiu uid b; EtSrlal ropeways.
Aftsb having been excavated, the miDeral must be conveyed
to the Burfac6. In very many caaes the journey ia peiformed in
two stages — first, along a more or len horizontal road to the shaft-
bottom ; and thence by a vertical or inclined road which leads up
to the daylight. The first proceee is often spoken of as haulage
and the second as winding ; but there is no distinct line of de-
marcation between the two, for certain eloping paseagea, called
shafts by the ore-miner, would be denied that name by the collier.
It will be convenient to say a few words here about transport
above ground, although, strictly speaking, this subject should not
be dealt with until after the chapter on winding.
The transit of the mineral from the working-place to the
shaft may be carried on in part or wholly by one of the following
processes:
I. Fall down a Bhoot (mill or pan).
IL Flow along pipea or iroagba (laattderM).
Ill, CniriagB by peraoBB.
rv. ConTeyance by sledges.
V. „ „ vehiolas with wheels.
VI, „ „ boats.
I. PALIi Down A SHOOT.— This first method is one to
which reference has already been made more than once in
deacrilnng the modes of working. When a deposit is inclined at
a steep angle, or when a mass has to be dealt with, the mineral
will readily d^p from the working-place to the level below. The
passages provided for this purpose are called " shoote," " passes,"
or " mills."
If the excavation is filled up with rubbish, a apace like a small
shaft is reserved in the stowing by building a wall with some
of the large stones. This kind of "peas" may be described as
a large chimney, about 3 feet in diameter, lined with coarse
rubble masonry. To prevent choking, it is advisable to make
the pass slightly conical, the large end at the bottom. It may
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HAULAGE OR TRANSPORT. 349
be coDBtruoted in the middle of the rubbish, or if there is s,
convement smooth face on the footwall of a. lode, a, aemicirculor
wall built against it encloses a space very suitable for the purpose
required. The pass may serve also as a climbing way for the
men, especially if it is provided with a chain ; bat it should be
used in this manner only for short distances. It is far better to
keep the ore-pass distinct from the climbing way, in case any
Btonee should lodge oa the sides and fall during the ascent or
descent of the men.
A pass is often lined with timber instead of stone, and some-
times it is merely an intermediate shaft or winze set apajt as a
shoot. At the Van Mine the passes, whether they are small
shafts sunk on purpose, or passages res^red in the rubbish
used as filling, are 6 feet by 3 feet, within the timber ;
each pass is divided into two unequal compartments hy a.
partition made of i^-inch plank nailed to cross-timbers
called dividings, and the larger one is closely lined with similar
planks. This forms the "^oot" proper. The small compart-
ment is provided with ladders and serves as a climbing way, and
is also useful in case the larger one should become choked ;
a board can be taken out from the side at any time, and large
stones obstructing the passage can be dislodged with safety.
Vertical passes lined with timber sometimes have pieces of steel
rail put across at intervals, to break the fall of the "stuff."
The pass is provided at the bottom with a mouth closed by a
door of some lund, and when this is opened, the mineral falls out
into the waggon which has been brought underneath.
n. FLOW AltOITQ FIPBS. — This method of transport
becomes available when one has to deal with liquid or gaseous
minerals, or with solutions, but these cases occur more frequently
above than below ground. However, brine is led along wooden
launders and pipes in some salt mines. Natural inflammable ga»
in a few exceptional cases is piped off from a blower and burnt
for illuminating purposes ; this is done at a salt mine at Bex in
Switierland.
III. CABBIAGE BY FEBSOITS.— The simplest and no
doubt the oldest method of transport along underground roads is
carriage by persons. It still survives in some places for short
In the Forest of Dean, boys carry iron ore on the back in oval
trays, called "billies," from the actual working-place to the
neuest barrow-road or waggon-road. The tray is made of wood,
with a rim of sheet iron, and is about 6 inches deep, 22 inches
in length in the direction of the long axis, and i z to 1 5 in the
direction of the short (me. The load carried in a " billy " varies,
according to the nature of the ore and the strength of the lad,
from 90 to 112 Ibe. or even m<»e. The lad goes on all-fours,
using his hands to support himself as he makes his way through
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35° ORE Ai'D STOKE-MINING.
low and tortuoos passages. This method of ttansport i& retidet«d
neceSBoi; by the nature of the excavations, which are very irreg-
ular ; but the distances along which the ore ie carried are small,
generally from 30 or 40 to 50 yards, and rarely as much as
100 yards.
The Qerman miner commonly makes use of a tray into which
he scrapes his mineral or rubbish with a tool like a hoe, and he
then carries his load to the nearest " pass " or to a waggon-road
in the immediate neighbourhood.
In the little slate mines near Gochem on the MoseUe, men and
lads carry up the blocks of slate upon their backs, walking upon
steps cut in the rock. Th^ come up ivith their hands upon
the ground, bent almost douUe under the weight of the block,
wbiidi rests upon a thick pad. Again, blocks of slate are stdll
carried on the back from the working-place to the wsggon-roads
in the slate mines of the Ardennes. In the Sicilian sulphur
mines the same method is common, and it is also found in
some parts of Spain and China, where baskets are used, whilst
bags are employed in Uezico and Japan. Indeed, in these cases,
as at Cochem, the mineral is not only carried along comparatively
level roads but is also brought to the surface.
lY. CONVEYANCE BY SLED QES.— Sledges, or sleds,
enable greater loads to be transported ; but they are not available
unless the conveyance takes place along roads sloping downwards.
They are little employed underground.
V. CONVEY ANCE BY VEHICLES WITH WHEELS.—
We now come to the methods by which minerals and rubbish are
usually transported both above and below groimd — vii., by some
kind of wheeled vehicle. Here we may at once make two claasee.
A. Vehicles running upon the ground or on boards ; B. vehicles
running upon rails.
A. Vehicles Bunning on the Ground or on Boards. —
Wheelbarrow; The simplest wheeled carriage is 4^e barrow.
It consists of a body with two handles and one wheel. The
harrow used in Cornwall at the present day is not unlike that
figured more than three centuries ago by Agricola. It has
no legs, but in many ore-mines a barrow with legs is em-
ployed, somewhat resembling a navvy's barrow. Mine-barrows
are usually made of wood, and have either a wooden or a steel
wheel. The Comiah barrow is tipped sideways, whilst the barrow
with legs is tipped either sideways or over the end. This latter
form of barrow requires a higher and better level ; it is a more
advantageous appliance, as it throws a greater part of the load on
to the wheel ana relieves the miner'a arms to a certain extent.
The barrow often runs along the natural floor of the working-
place or level, but less labour is required if it is provided with a
road made of planks or strips of iron.
Carta and Waggons. — In the low passages, only 18 inches xo
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HATJIAGE OR TRANSPORT. 351
30 inches high (Fahrten), leading from the working face of the
ooppeT-ahale mines at Manafeld to the main roods, tiny waggons
on tour wheels are emplojed.
Oartfl drawn hy horses are used in some large underground
quarries.
A mine waggon largely employed in Qermany at one time, and
still seen occasionally, is the ao-coUed Hungarian " Hund." It
has a rectangular body resting upon four wheels, two small in
front and two large near the middle ; the workman presses down a
little handle at the back to maJie the load rest upon the two big
wheels only, and pushes the waggon along a board at the bottom
of the level. The Qermans have also used four-wheeled waggons
running upon two boards ; and they were sometimes provided with
a projecting pin underneath which kept them upon the track.
B. Vehloles Banning npon Badls. — The points to be con-
siderd are (a) the road ; {b) the waggons ; {a) the power employed
for traction.
(a) Bailways. — Cast-iron tram-plates were introduced in the
last century, and were succeeded by wrougbt-iron rails ; these in
their turn are being superseded by rails inade of steel. Yarioos
forms of rails are in use. The simplest is a bar of iron set on
its edge, or a strip of flat iron naOed to longitudinal sleepers.
Bails (^ the former kind ore made, for instance, of bars 1 1^ 3^
inches, or J by 2| inches, £xed by wooden wedges in slits cut in
the sleepers. This rail has the disadvantage of wearing a groove
in the ^nge of the wheel, but it is easily and quickly laid and
readily bent into curves. Rails made of bars of round iron are
used in some Welsh slate quarries.
The bridge-rail was in great favour at one time, either laid
upon longitudinal or cross sleepers; but nowadays flanged
T-headed rails made of steel are preferred. Care should be
taken to have strong and well-laid lines, especially where there is
likely to be much traffic. In tim, as in many other depart-
ments of mining, it is very bad
economy to cut down the on- ^'°- 397. Via. 398.
einal expenses too much. What t" ^
IS saved on the first cost will be tl J gmm^
spent over and over again in \ \^' /^
repairs, to say nothing of the \ ^ '/^
loss of time and money caused p |J
by delays in the traffic. ^j _-,^^~.^
The gauge varies from 14 ^^....fi^^^!^ ^^^^^."^^^
inches to 3 feet gt more ; 20 mu«
inches to a 2 inches is a common ."'''.'. . '**
gauge in vein mining. The '" "■
weight of the rails for such roads is from 10 to 30 lbs. per yard.
Figs. 397 and 398 show the sections adopted respectively by
Legnmd of Mens and Howard of Bedford, for rails weighing
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352
ORB AND STONE-MINING.
i8 IbB. per 5&rd. The nils m&y be simply spiked to wooden
sleepers, or the^ may be laid in chairs. In important roads fish-
plates should be used.
There is a tendency at the present day to adopt steel sleepers,
which are supplied I^ the makers to suit roads of various gauges,
lliey have proved to be very convenient and effident, aad in
this country they are cheaper in the end thui wood. Among
their advantages are exact uniformity of gauge, easy and rapid
laying, fewer repairs. They are usually made of rolled steel, and
the rails are fixed either by clips, or by clips and keys.
One form of road supplied by Legrand of Mons (Fig. 399), has
the clips of one sleeper on the outside <tf the rail and those of the
next on the inside (^ the rail. The clips are firmly riveted to
the sleepers. In constructing the road, the sleepers B are laid
at suitable distances apart, exactly parallel to one another ; the
alternate sleepers A are then put in obliquely, as shown by the
dotted lines, and knocked into position with a hammer ; tbe
rails are joined by fish-plates.
Howanl's sleeper (Fig. 400) is made from a plate of steel rolled
with a corrugation ; the lips which constitute the chain for the
rails are formed by pressing
Fia, 400, down this corrugation with-
out cuttiog away any of the
metal. The jointing sleepers
have a double corrugation,
and the rails are fastened
with a simple key which
is serrated on one side. Some of Howard's sleepers for under-
ground work can be used without any keys.
Bagnall's sleeper is also distinguished by longitudinal corru-
gations which B^en it and prevent its buckling. The Widnes
Chair and Sleeper Company prefer a section like that of a V-sh^ied
trough ; they claim that ^e penetration of this sleeper into the
ground ensures great stability.
Where a mine has a stock of old rails or old iron, it is often
more economical to convert it into sleepers than to sell it as stxap.
cE
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HAULAGE OR TRANSPORT.
353
There are several methods in use. White * of Widnes utilises old
bridge rails (Figs. 401 and 401a) by inserting two clips (Figs. 403
and 402a) into a piece of rail cut to the required length ; the
clip is held in place by a piu which passes into a hole punched
Fia. 401.
Tia, 401a.
in the sleeper. At the Llechwedd slate mine in North Wales,
two other methods have been devised by Mr, C. Warren Roberts
(E^igs. 403 and 404) for utilising old channel iron and flat iron.
Stamped iron clips are riveted on so as to take the outer ade of
Fig. 403.
-t™.
the flange of the nul, and similar clips are bolted on against the '
inner flange. In order to allow for any small irregulanly in the
widtii of the flange, the hole for the bolt is made oval, and this
enables the clip to be adjusted to the flange exactly.
• Engineering, voL Iv., 1893, p. 146.
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354
ORE AND BTOME-MININa.
Points and croaaiiigs must be provided. The points may be
lite those of an ordioaiy railway, with tongues moved by levers.
Another plan is to leave gaps between the rails where the lines
diverge or cross, and interpose plates of cast-iron upon which the
flanges of the wheels run without any difficulty. This arrange-
ment is suitable for cases where a man is pushing the waggon, for
be can turn it on to whichever road he chooses, but it will not
answer in the case of haulage by engine power. Each plate has a
rim or edge on the outer side, which prevents the wheels from
running off.
Flat plates are commonly used where there is a very sharp
bend in the road, such as when a cross-cut joins a level ahnost, il
not quite, at right angles. The plate is made of cast-iron with
ridges forming prolongations cS the rails as shown in Fig. 405.
Fio. 405.
Fta. 406.
"^f
The waggon leaves the metals and the flanges of the wheels run
upon the plate ; as it« surface is perfectly smooth, the waggon
is easily tumeid into the requirod direction, and the curved
ridges guide the wheels into the track which they have to
follow.
In places where there is a difficulty in procuring a casting,
the plate may be made of sheet iron, and the necessary
guiding ridges are formed by the overlapping ends of the rails.
The flange of the rail is cut away for a length of 8 or 9
inches and also part of the web ; the projecting piece of the head
is then hammered out so that the top of the nil slopes down
sufficiently to touch the plate.
Another device for guiding a waggon from a plate on to a
line of rails is a curved piece of round iron, i inch in diameter
(fig. 406), The two ends are bent at right angles and sharpened
BO that they can be driven into a sleeper at the edge of the flat
plate. The ridge formed by this piece of iron, guides the inner
side of the flange of the wheel.
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HAULAGE OB TRANSPORT. 355
The inclination of the road is not without importance, because
there are usually waggons travelling in both directions, full oaes
going towaiilB the shaft or other outlet from the mine, and empty
ones returning to the working- places. The inclination down-
wards towards the shaft assists the work, but if it is too great the
return journey causes a useleee expenditure of labour.
The rule in many ore-mines is to drive the levels as flat as
possible, with only just slope enough to make the water flow
-away ; the tendency of the workmen is always bo rise too much,
and one sometimes meets with old levels where, through careless-
ness or inattention of the agent, the loss of level is very consider-
able. An inclination of ^ to | inch per yard, or i in 216 to i in
The condition of the road between the metals deserves more
attention than is usually bestowed upon it. There is unneces-
sary labour on the part of the man or the horse employed in
traction, if the road upon which he walks presents obstacles
through great unevenness. I have seen roads which were simply
a succession of deep puddles between the sleepers, a striking con-
trast to the well-kept main levels at the Mansfeld copper mines.
These levels are carefully paved with artificial stones, made from
slag at the Company's smelting works. The paving-stones are
about 5 inches square at the top and 6 inches deep : they are
-also sold to the public, at prices varying from ^. to id. each.
(b) Waggons. — Mine-waggons are made of wood, iron or steel.
They consist of a body or box resting on a frame carried by four
wheels. They vary greatly in shape and sise according to the
nature of the excavation and the kind
«f matttial transported. FiQ. 407-
Figure 407 represents the plain but
strong waggon of the Tan Mine,
Montgomeryshire, with a rectangular
body of sheet iron, an oak frame and
cast steel wheels. The top is strength-
ened by a band of flat iron, .The
wheels are 11^ inches in diameter and
are just low enough to go under the body ; they are therefore
protected from blows, to which they would otherwise be liable
from stones dropping during the process of filling. The waggon
is emptied by b«ng run in to a " tippler," that is to say, a cage
turning on pivots, which enables it to be completely overturned.
At the Mansfeld copper mines the general shape is similar.
Formerly waggons of various shapes and sizes were in use, but
now one uniform model has been adopted. The body is made of
sheet-iron i inch thick, and the upper edge is strengthened by an
iron band \^ inch thick and z^ inches wide, whilst the comers
are stiffened with angle Iron. The body is 5 feet 5^ inches long,
2 feet 2 inches broad, and i foot io£ inches deep inside. The
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356
ORE AUD STONE-MIKING.
capacity of the waggon ia 13^ cubic feet, and it carriee 10 cwt.
The body reets apon two pieces of iron placed leogthwiae,
acroaa wluch are fixed the two axles. The wheels are oS chilled
caat-irou with special grease-boxes. The gauge of the road is
19^ inches, and the wheels are iij inches in diameter, so that
they can be placed under the waggon. The total height of the
waggon is 3 feet i inch, and it weighs 716 lbs.
When made of sheet-iron or steel the sides can be bent, as
shown in Figs. 408 and 409, and larger wheels can be employed
without unduly raising the body.
In order to suit the small levels of some vein mines, the waggons
are made long and narrow. In the Isle of Man, one meete with
waggons 6 feet long and only 1 9 to 21 inches wide at the top ;
the depth being 3 feet. The sides slope inwards so that the bottom
is only 13 inches wide by 4 feet 9 inches, or 5 feet long. The
waggons are made of sheet steel about ^ inch thick, or of ij Inch
710.409.
FIG. 40S.
i
j
C^Im^
3
^Ht.«l!LW,-^^
plank. The discharge is by a door at one end, kept in its place
by a bolt. When the waggon has to be emptied, the niiner
knocks up this bolt and lifts the waggon up behind till it slopes
enough for the " stuff " to run out. The top of the steel waggons
is stiffened by a band of J-inch iron 2 inches wide firmly riveted
on, and pieces of angle-iron, where the plates come together, give
a further amount of strength. Woiiden waggons have the
bottom lined with sheet-iron ^ inch thick.
The diameter and nature of the wheels vary. At one mine
in the Isle of Mb-ti the wheels are loj^ inches in diameter, and run
loose upon the axles, which are bolted to the frame under the body ;
they are 15 inches apart, from centre to centre. The wheels are
brought close together with a view of making the waggons pass
round curves without trouble. In order to render the tipping
easy, the centre of the front axle is placed 6 inches in front of the
middle of the waggon ; the miner, therefore, has the greater part
of his load balan^ when he pivots his waggon on the axle of the
front wheels in the act of discharging it.
At a neighbouring mine under very similar oonditions cast-
iron brackets are bolted under the body to receive the two axles
to which the wheels are firmly keyed, but the hinder axle is not
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HAULAGE OR TRANSPORT. 357
in any way attached to the bracket ; when it ie desired to empty
the waggon, the hiud end is lifted up and both sets of wheels
remain on the ground. The hind axle is made fast to the front
oue by a couple of straps, for otherwise the hind wheels might run
aw&y when the waggon was emptied. A disadvantage of this kind
of waggon is that it may require two mea to replace it on the
road if it comes off; one may be wanted to Bee that the wheels
will drop properly on to the rails, while the other is managing
the body.
In both these waggons the wheels project outside the body,
instead of being underneath it out of harm's way, but they are
protected to a certain extent by the overhanging sides, and they
can be further screened by riveting on little shields of sheet-iron.
The lateral position of the wheels reduces the height of the waggon
required for any given capacity, a decided advantage when it has
to be filled with the shovel ; but in ordinary vein mining the ore
ought to be drawn down from shoots, and therefore the benefit of
easier shovelling comes into play only when loading rubbish or ore
in Buoh places as the " ends.
In some mines the mineral is loaded in the levd into an iron
bucket (kibbU) standing upon a trolley, which is merely a small
platform upon four wheels. This trolley is pushed (tramtne£f to
the shaft ; the full kibble ia hooked on to the winding rope and
drawn up, whilst an empty kibble is placed upon the trolley and
trammed along the level to the spot where it is again loaded from
a shoot or by the shovel.
Wheels for mine-waggons generally have a single flange, and
are made of ordinary cast-iron, chilled cast-iron, cast-steel, or
fotged steel. Steel and chilled cast-iron are the materials most
in favour; both have advantages. The wheels made of chilled
caat-iron are rather heavier than those of steel, and are brittle;
the flange, for instance, will break under a blow which will not
damage a steel wheel ; but a pair of chilled wheels will often
outwear several pairs of steel wheels if they happen to escape
the hard raps to which mine-waggons are liable.
Under Eyre's patent, wheels are made by forging a steel
Uotnu under a steam-hammer into dies; they are reported to
give great satisfaction and to be capable of standing much knock-
ing about.
Wheels with two flanges are used in the Festiniog slate mines,
and are considered best fitted for the work on account of the sharp
turns in the roads.
Much difference of opinion and practice exists concerning the
attachment of the wheels. Four systems are in vogue : axles
fixed and wheels running loose on them; wheels fixed to the
axles, which run loose in pedestals attached to the frame or to
the body of the waggon; thirdly, a combination of these two
systems — viz., wheels running loose on the axles and axles run-
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3S8 ORE AND STONE-MINING.
ning loose in tbe pedaetab ; fourthly, one wheel fast on the axle,
and the other loose.
At a first glance it might be thought that it would undoubtedly be-
hest to follow the lead of the great railways, and have the wheels
fixed to the axles, because experieiuie has shown that this Bystem
answers so well above ground. Nevertheless, it must be remem-
bei-ed that the conditions of underground roads are often very
different, the curves are frequently of veiy small radius, and
there is usually more difficulty in keeping the roads in perfect
order. By allowing the wheels and axles both to be loose, the
Festiniog miner, for instance, who may be tramming out a
block of slate i8 feet long, can slew his load on the truck
and so pass round sharp curves which would oppose an insur-
mountable obstacle if the wheels or axles were fixed. Loose
wheels with loose axles look clumsy and unnatural, and in spite
of all that may be said in their defence, it is probable that it
would in many cases pay the mine owner to improve the condiUon
of his roads and so render a more stable form of waggon
available.
Lubrication of the bearing parts is too often performed in a
perfunctory imd wasteful manner, especially in mines where the
waggon never comes to the surface except for repairs. A little
grease or oil applied at the b^inning and in the middle of the
shift is all that is considered necessary. Such a procedure must
be defective; either there is too much of the lubricant at first, or
there is too little after the waggon has been in use for a time.
An automatic lubricating apparatus is sometimes fixed in the
road and every waggon is greased in going over it. The ap3>a'
ratus consists of a wheel placed in a trough containing the
grease, and as each axle touches this wheel it receives a little
lubricant. A defect of these lubricators is that when a waggon
is going at great speed, as is the case with some systems of
underground haulage, the grease is fiung about and wasted ;
besides, where a bearing can be greased in this manner It
is necessarily exposed to the dust or mud of the mine, which
must cause wear and friction. It is better to provide constant
lubrication and to protect the bearing parts as much as possible
from dirt.
One method by which this object is attained is shown in Figs. 4 1 o
and 41 1, which represent a waggon used at some colheries at Saint
Etienne, in France, and embodying the results of long experience.
The wheel, which is made of steel, is placed under the waggon,
and the journal is encased in a chamber kept full of oil. The
chamber has two holes which serve for passing in the linch-pin
and putting in the oil. They are afterwards closed with plugs.
Other points which may be noticed about this waggon are its
shape and mode of construction. The body is oval and made up
of wooden staves like a barrel.
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HAULAGE OR TRANSPORT. 359
Ax an example of a waggon constructed entirely of steel,
I tftke a "tnun" designed for the Llanbradach oolliMy hj
Mr. Galloway (Figs. 413 and 413). The body has the form
of a very blunt oval; it is made of sheet steel /^ inch thick,
stiffened round the top br channel steel. The wheels are fixed
to the azlee, which are kept constantly lubricated by Staufier's
InbricatoTs placed immediately above Uiem in the hoUow axle-
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3*0
OBE AND STONE-MUTING.
boxes. The empty^ waggon wei^ie ii cwt. and will cany 3 tents
of coal, when tlie load is built up higher than the sidefl.
When dealing with a tender mineral like oool, which decreaaee
in value if knocked about, it is important to reduce the effects of
bumping to a minimum ; and with this object in view the «
reetfl upon springs and the buffers are elastic. The conse-
quence is that the waggon runs verj smoothly, and is likely to
require less expenditure for repairs than one constructed in the
ordinary fashion without these appliances. There will likewise
be a diminution in the quantity of dust dropped on the road, a
matter of moment in colHeries.
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HAULAGE OR TRANSPORT. 361
The Hardy Patent Pick Company makes self-oiling pedestals
for waggons with the wheels fast upon the axles (Fig. 414);
a is the upper part of the pedestal, and h the lower part,
coBtaining felt or wool saturated with oil. This presses lightly
against the axle and keeps it oiled
for several weeks, without re- Via. 414-
quiring any attention.
It will be seen from these
remarks that a number of poiate
hare to bo considered in design-
ing a mine-waggon. They may
be summed up as follows :
Smallest weight compatible
with strength.
Small height, if the waggon is to be filled with the shovel.
Protection of the wheels from injury.
Constant lubrication.
Adoption of a uniform type of waggon for the mine.
Material which causes the least expenditure for repairs.
Easy handling and easy replacement upon the rails.
In a few exceptional cases the miueral raised in the mine does
not require a box or chest. This happens with slate, for the
blocks are brought up on trucks to which they are made fast by
(c) Power used for TTndergroiuid Transport.
The soarcee of power are as follows :
I. Hen, boys, women, aod girls,
3. Horses, ponies, donkeys, and mnles,
3. OiBTitj acting upon the material maved.
4. Machineg driren bj staam, water, compressed air, and elec-
tricltj.
I. HamaiL Labour. — Female labour underground is prohibited
by law in the United Kingdom, and no doubt it is destined to
disappear in other countries. We need only deal with men and
boys. Where the passa^a are high enough to take waggons
standing 3 feet above the ground, men are usually employed for
drawing or pushing them. It is convenient to have waggons small
enough to be handled by one man, and also to be put back on
to the road by one man, if by chance they leave the rails.
The large waggons and loads at Feetiuiog require two men,
for the load of rubbish commonly amounts to i J or 2 tons. The
waggon and load together may weigh as much as ai tons. The
men who posh out these waggons usually do the loading also,
shorelling in the small pieces and lifting on the large ones.
3. Animal Iiaboor. — Traction by horses or ponies is cheaper
than using human power, bat it is not always practicable to
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362 ORE AND STONE-MINING.
employ it. There are m&Qy ore mines in which it would be
impossible to lower a horse down the shaft ; and even where the
descent could take place, there would often be the further dtKW-
back, that as the work proceeds with comparative slowness, owin^
to the hardneaa of ths rock, there would not be "stuff" euou||[li
broken in a givsn time to keep a horse constantly employed at
any particular level, whilst shifting it from one level to another
would entail much difficulty.
The load drawn by a horse at the Festinio; slate mine« is as
much as eight waggons, a gross weight of 20 tons, en- net weight of
t6 tons, along a road with an inchnation of ^ inch per yard.
Where a mine is entered by a shaft, the horses are stabled
below ground, and much care is taken in many instances to
provide proper accommodation for them. The stables are paved
with bricks or concrete, sloping towards a gutter ; each horse has
its stall, or a loose board is hung between every horse and its
neighbour. Glean water is at hand for drinking. At a French
colliery I found the daily allowance of food to be sa follows:
Oats 10 kU. (22 lbs.)
Chopped bay from lentil and rye grass . 5 kU. (i i lbs.)
Bnn 2kfl. (4-4lbB.)
In addition each horse had 5 kil. (i i lbs.) of straw per day as
litter.
The horses do not always belong to the mining company ; at
Festiniog, where the workings can be entered by adite, horses are
hired from persons in the district, who supply a horae and mas
for eight shillings per day, and pay all the cost of food and
stabling.
3. QraTity. — In working stratified deposits, it is often necessary
or convenient to lower a waggon down an inclined plane made
along the dip. At Manefeld, for instance, instead of maintaining
a number of levels at abort intervals apart-, it is more economical
to reserve only a few for traffic, and abandon certain portions,
as already pointed out in Chapter YI. The waggons then
have to be lowered from the working level to one which is
kept up as a main roadway. Inclines for this purpose have
two lines of rails, one for the descending and the other for
the ascending waggon. A wire rope or a chain passes round
a pulley or drum at the top, the axis of which may be
horizontal or at right angles to the plane of the deposit.
Each end of the rope can be hooked on to a waggon, and
the weight of the full waggon going down suffices to raise the
empty one. The speed is regulated by a brake on the pulley
or drum.
Another method of working inclines is to make the full
WHggon draw up a weight, running on a special line of rails,
which is heavy enough bo bring up the empty when it de-
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HAULAGE OR TRANSPORT. 363
sceods. In order to economise apace, the line of rails for the
weight iaa.y be made narrower thajt the one used for the waggon,
and may be laid between the two main rails.
If the incline is steep, a carriage with a horizontal platform ie
provided. The mine-waggon is pnahed on to this travelling
platform and ascends or descends in its ordinary poeition.
4. Haohinery. — Undergronnd haulage may be carried on
either by travelling engines or stationary engines.
LooomotiTefl tired with coal have the great disadvantage
of polluting the air by the products of combustion, consequently
they are not available unless the ventilfttion is very good, nor
unless there is absence of inflammable gases and freedom from
the risk of setting fire to the timberiag or to the mineral it«elf.
A small locomotive of two horse-power nominal is used on an
18^ inch track in the long adit of the Oreat Laxey lead and
zinc mine in the Isle of Man ; and at Rio Tinto in Spain a much
larger engine plies in the adit on a line with a gauge of 3 feet 6
inches.
Locomotives driven by compressed air, carried in a reeervoir
upon a tender, improve the ventilation instead of injuring it, and
are not a possible source of danger from fire ; but, except in
special cases, they cannot be worked so cheaply as engines fired
with coal. However, the advantages they afibrd have led to their
adoption in some mines ; Lishman and Young's air locomotive
is employed in several collieries in the North of Kngland.
To overcome the inconveniences and dangerB of engines of the
ordinary type, fireless locomotives have been proposed and con-
structed. That of Lamm and Pnuick has a cylindrical reservoir,
instead of the boiler, filled three-quarters full of water. The
reservoir is heated by steam from the surface, until it is capable
of giving off vapour with a pressure of 335 to 294 lbs. per square
incSi (16 to 20 atmospheres). As the temperature and conse-
quently the pressure of the steam supplied by. the rMervoir are
constantly falling, a regulator is interposed between the
reservoir and the steam cylinder, which enables both the pres-
sure of the ateam and the amount of expansion to be changed at
will. This arrangement renders extra power available if a steep
gradient has to be mounted.
Holland's fireless locomotive is similar.* His reservoir has a
capacity of 19^^ cubic feet (0.550 cb.m.), and contains water at &
temperature of 205° 0., or with a pressure of 235 lbs. per square
inch (16 atmospheres). M. Holland states that his locomotive,
charged in this fashion, will run for 3 to z^ miles (3 to 4 kms.).
When going at a speed of 3 m. (6 feet 6J inches) per second, the
locomotive exerte 6 h.p. ; the speed of a horse may be taken as
0.9 to r m. (3 to 3J feet). The locomotive ready for work weighs
three tons.
■ B. undli. Zeitung, 1890, p. 375.
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364 ORE AND STONE-MINING.
Ab pointed out by Boll&ad, the fireless locomotives have the
following advantages in addition to being more economical :
No danger of fire and no inconvenience from smoke.
Improvement in the atmoephere of the mine, owing to absence
of the horses and their droppings.
The Honigmann * locomotive depends upon the fact that a
solution of caustic soda, of a certain streogth, will absorb steam
and give out heat. This heat is utilised to convert hot water
into Bt«am, which works an engine and then passes into the soda
solution, causing a furthra- development of heat. The process of
steam-making goes on thus of itself, until the soda solution
reaches a certain stage of dilution. The locomotive is re-
stored to a state of activity by bringing back the solution to
the proper degree of saturation. This is done by passing steam
from a stationary boiler through coils of tubes in the reservoir
containing the soda, a process occupying little time.
Experiments have been made, and wUi be continued, with the
Honigmann soda locomotive, and also with Eraoss' tunnel
locomotive, at the Mansfeld copper mines.
Stationary Engines. — An enormous amount of underground
traffic is carried on by some system in which the power for
haulage is derived from an engine placed above or below ground ;
but the practice is far more developed in collieries than in vein
mines, where the quantities of mineral to be handled are as a rule
very much smaller.
With reference to the application of the power itself, the
various systems of underground haulage might be classified thus :
Steam or water power at the barface, | i. Bopes.
trADBmitted to machinarj ander- 1 2. Compiewed air.
grannd by j 3. Electricity.
Water power below groDUd driving the machinery.
s— p„„ b-o, ,^i M«.g .h.j'*":";frr:?'
The subject of the transmission of power has already been
sufficiently discussed in Chapter lY., and need not be dealt with
bore, save that it is necessary to point out that the conditions
of the problem are not the same when power has to be applied
to haulage, as when it is required in a constantly changing
working face. As the mineral has to be brought to the shaft, the
engine and its boiler, if necessary, can be placed in the immediate
vicinity of the pit-bottom and the exhaust steam can he got rid of
without interfering with the comfort of the men or injuring the
condition of the workings. Proper rooms can be made for the
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HAULAGE OB TRANSPORT. 365
engine and the boiler, coal con be brought down and the ashes
removed without difficulty. Ereiything can be arranged in a
permanent and substantial fashion, so that steam power may be
generated for haulage purposes below ground when it would not
be pi-acticable to employ it for breaking down the mineral.
Again, when power has merely to be transmitted down a vertical
sli^t in order to work a dram near the bottom, endless ropes may
be uited, although they would be quite out of place if they had to
be carried along narrow, low, and crooked levels. For subsidiary
haulage purposes — that is to say, for bringing trams from the
immediate vicinity of the workings to a main line — Galloway
employs a small engine with two drums placed upon a waggon,
which is small enough to go into the cage and which will run
upon its own wheels along the underground railways. It can
therefore be moved about as required, and when coupled up to
the compressed air main can be set to work immediately to haul
out trams, instead of employing horses for this work.
We will suppose that the question of the most suitable driving
machinery has been settled according to the circumstances of the
case, and that the miner has to consider how he will apply it
to the transport of mineral.
Five systems are in use :
i. Single rope.
ii Ham and tail ropea.
iii. Endless rope,
iv. Bndlesa chain .
v. Eleotrio railwaTS.
i. Single Bope.-^This system is available with a road
sufficiently inclined for the empty waggon to run down of iteelf,
after the load has been brought up, and draw back the rope with
it. One road will suffice, and the machinery required will be
some kind of drum, around which the rope is coiled, and an
engine for driving it.
The drum is usually placed horizontally ; it is provided with a
brake, and there is a disengaging clutch by which it can be thrown
in or out of gear with the engine. A pair of horizontal engines,
which have their cranks upon the drum-shaft, or which drive it
by means of a pinion and spur wheel, form the common method of
applying the power.
The wire rope haa one end £zed to the drum and the other
is provided wi^ a hook of some kind ; this is attached to a link of
the coupling chain of the truck and the load is drawn up. On
reaching the top of the incline or engine-plane, the waggon is
unhooked, and either pushed or allowed to travel of itself, under
the action of gravity, to the pit-bottom, where the onsetter runs it
on to the cage in which it is raised to the surface.
An empty wa^on is then hooked on and run on to the incline,
and the engine-man, with bis brake under proper control, dis-
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366 ORE AND STONE-MINLNG.
engages the dram hy means of the clutch and lowers the load
without UBiDg Any steam. When worked in this w&j, the incliDe
requires onl^ one line of rails. A seriee of rollers have to be put
in for the purpose of keeping the rope from trailing on the ground
and of thus preventing much unnecessary wear and friction. These
rollers are small wooden, cast-iron, or steel cylinders, often with a
low flange at each end to keep the rope in its place ; they are laid
horizontally and are capable of revolving around a horizontal
spindle. Care is, or ought to be, taken to see that they are very
correctly set and that they are well lubricated, so that they may
revolve freely when the rope is drawn over them ; otherwise the
Htranda are sure to be worn down rapidly from rubbing against
The incline may also be worked with two lines of rails, after
the fashion of the self-acting inclines ; and this system has the
advantage of being more economical, for the deadweight of the
loaded waggon coming up is balanced by the weight of the empty
one going down. It is not even necessary to have two lines all
the way ; provided there is a sufiScient length of double line where
Pie. 415.
~^ r." irr."!."-®''
<gg--
the waggons meet, the incline can be worked with a length of
single line at the top and a similar length of single line at the
bottom. To prevent a waggon from running down in case a
coupling link or the rope should break, a safety appliance, called
a backstay, may be attached to it. It is a sort of fork which hangs
behind the waggon, and just touches the ground ; if the rope
breaks, it digs itself into the road and prevents the waggon from
going down. Of course it can only he used while the waggons are
being raised, but it is during the journey of the loaded waggon
that the rope is most likely to break.
ii. Madn and Toil Bopes. — On the engine planes just
described, the empty waggon goes back under the action of
gravity; but with very slightly inclined, flat, or undulating roads
this is impossible. One method of getting over this difficulty is
to add ft rope, called the " tail rope," which will draw the empties
back ; the rope which draws the full waggons is known as the
" main rope."
The system is perhaps best explained by a diagram (Fig. 415) : a
is a drum upon which is coUed the strong main rope ; h is another
drum upon which is coiled the tail rope, passinground the pulley c.
The waggons are coupled together and form the train or "set,"
which may in reality consist of as many as 100 wagons. Suitable
dutches enable either drum to be worked at pleasure by the
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HAULAGE OR TRANSPORT, 367
engine, while the other is allowed to ruB loose upon the shaft.
Each drum has a brake, by means of which the rope can be
prevented from becoming too slack while uncoiling itself. When
the drum a is made to revolve by the engine, the main rope
is wound up, the drum 6 running loose, and the train or "set"
is drawn from c to a. Here the waggons are uncoupled and
pushed to the shaft, or, better, the station at a is arranged so
that it is sufficiently high for the waggons to run down of them-
selves under the action of gravity. A new train of empties is
then made up, the tail and main ropee are attached to it and the
drum b is set in motion so as to wind up the tail rope and draw
the waggons into the terminus at c. It will be evident from a
^ance at the figure that the tail rope must be twice as long astlie
main rope. Aja the tail rope has simply a train of empties to haul
out, it may be made smaller than the main rope, except in cases
where the road has a downward inclination towards the shaft
sufficient to cause the loaded train to run down of itself and draw
the tail rope after it.
A single line suffices for this system of haulage; the main
rope lies in the middle of the road, resting upon a series of
horizontal rollers similar to those used upon ordinary inclined
planes. Where there are curves, however, the rope must be
guided by small vertical rollers. The tail rope is brought along
^e side of the road, or if more oonvenient, along a separate road,
also resting upon rollers or pulleys and suitably guided at the
curves. The system is applicable to roads of var3ring gradients,
and arrangements can easily be made for working branches, by
having a special piece of tail rope in each branch going round a
pulley at the end of it. When mineral has to be drawn away
from the branch, the piece of tail rope on the main road beyond
the junction is disconnected, and the piece belonging to the
branch is attached. Traffic then goes on as before, save that the
train is made up in the branch. Another plan is to disconnect
the tail rope at the end of the train, and couple one end of the
branch rope to the train and the other to the free end of the
ordinary tail rope. During the running of a train the tail ntpe
then goes round the pulley at the end of the main road, passes
round another at the junction of the two roads, prooeods along
the branch round its terminal pulley, and back to a pulley which
again puts it into the direction of the main road.
The trains are in a large number of cases made to run at a
great speed, even aa much as 10 or 15 miles or more an hour, and
if by some mischance an accident does happen from one 1^ the
waggons getting off the road, a good deal of damage may be done
to the ttain and roadway.
iii. EndleHS Bope. — A favourite method of underground
haulage is by an endless rope passing round a pulley at each
terminus, and generally travelling coatinuou^y in the same
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368 OKE AND STONE -MINING.
direction. The rope is kept in a state of tension bj
pasBing it round a tightening sheave, which in some instances
IS one of the tcrmuml piUIeys. lie tightening sheave or
pulley is carried by a frame running upon wheels, and is
constantlj drawn back by a heavy weight. The neceesaiy grip of
the rope is obtained by coiling it several times round the driving
drum, or around a driving pull^ with grooves and a second
grooved pulley close by ; the rope wraps itself, for instance, upon
three half circumferences of one pulley and two of the other.
The speed of an endless rope is usually from two to three miles an
hour, though instances might be cited of as low a ^teed as one
mile an hour. The endless rope system admits of so many modi^
fications that it is necessary at once to classify them before
entering into any details. We may begin by making two broad
divisions ; *
Waggortg Attached Singly. — Two distinct lines of rails are
required, because there is a constant stream of full waggons
coming out to the shaEt and a constant stream of emptdes going
into the workings.
This class has two subdivisions :
When the rope is above the waggons, no rollers are i
except at the curves. Several modes of attaching the wa^on to
the rope are in use.
If the gradient is all up hill a very simple clip is sufScient.
The rope is made to rest in a fork on the waggon, and as it
is bent shghtly out of the line of pull when in motion, it is
held tightly enough by friction to ibaw along the load. If the
gradient varies, a fork is put on each end of the waggon, or a
screw clip is employed ; this resembles a pair of tongs, the jaws
of which are brought tightly together by a Bcrew worked by a
handle, and hold the rope with a firm grip.
Another common atbichment is by a piece of chain 6 or 8 feet
long with a hook at each end. A boy puts one hook into an eye
on the drawbar of the waggon, and giving the other end of the
chain four turns round the rope makes it fast in the hook.
To detach a waggon the boy presses down the chain near the
waggon, takes out the hook from the drawbar, and then unwinds
the other end from the rope. After a little practice the boys
become very dexterous in this hooking on and off, and perform
* Tha clasrifleation and some of the Infoimadon is taken from the
CbCoIofTM of iht Eoj/al Mining, Engineering, and Indaitrial BaAibitum,
Nmceaitle-on- I)/7ie, 1S87, p. zxnv.
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HAULAGE OR TRANSFOKT. 369
these operationB with great rapidity. If thore is a downward
gradient the waggon would outrun the rope, and it ie neceasaiy
to put a chain at the rear end aa well as in front.
When the rope ia below the waggons, rollers are reqiyred on
the road, simiW to those already deecribed for engine-planes
and main and tail ropes. The attachment to the rope 13 made
by acme form of clip. At the Hodbarrow iron mine in Camber-
laad, Bice's clutch (Figs. 416 and 417) has been used for many
years with good results. The rope can be pat in or taken out
sideways after raising the sliding piece
A as Ear as the projecting pin. The clip Via. 416. Fio. 417.
is hung by its hook on to the waggon
and the rope is lifted in ; the motion of
the rope draws the clip a little away
from the vertical, and this slight devia-
tion of the groove from the line of pull
gives sufficient grip for haulage.'
The number of clips or clutches is
very great, and it would be useless to
attempt to describe them all within the
limits of this work.
An advantage of this system is the
smooth and regular manner in which it
works. The waggons are attached at
intervaJs of about 20 yards or even lees,
and they arrive without the bustle of
a long train. The men and boys are
kept constantly employed, but have ample time for doing all that
is required of them. If a waggon goes off the line, it is true
ttiat a large number of the succeeding ones may be thrown off
too, before the damage becomes known ; but the absence of a high
speed tends to render the consequences less perilous than with
the fast-running trains of the main and tail rope system.
Waggons Attached m Groupt or Trains (Sett). — As in the
previous case there are two subdivisions ;
The former of these two methoils is very easily understood.
For instance, several waggons may be coupled together and the
train thus formed is connected to the moving rope by a short
piece of chain with two hooks, in the manner described for a
single waggon. Other attachments are of course available.
The second subdivision admits of a great many varieties:
(a) Single road, with a siding or sidings for the full train to
pass the empty one. — (m) Single central siding. — The rope is
arranged in the form of a double loop, repreeented diagmmma-
ticaUyby the dotted line (Fig. 418); Sdraiotes the shaft end of the
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370 ORE AND STONE-MINING.
haulage aystem, W tbe end near the workinga, and C the central
siding. The full lines indicate the mili-oads. When moving in
the manner shomi by the arrows, the rope brings out a train of
full waggons from the workings, and takes in a train of empties
from the shaft. On arriving at the ceotral siding the rope ia
stopped, the empties are shunted on to the siding, and the
O.Vf=:=
Fia. 418.
train of full waggons is attached to the part of the rope which
has just brought in these empties. The empties are shunted
back on to the main line and attached to the part of the rope
just used for bringing out the full waggons. On reversing the
motion of the engme, the empties proceed to the workings and
the full train travels to the shaft.
(03) One or more sidings. — The two ropee (fig. 419) lie
within the road, except at the sidingn, each of which has one of
them. There are points at the ends of the sidings, for diverting the
trains on to the proper roads. Each train has a special truck, or
Fig. 419.
bogie, in front, upon which rides a conductor. It is his
to pick up with a hook the rope he requires, and grip it with hia
clutch ; hia train then moves along on to the main line till he
comes to a paas-hy. A boy attending to the points makes the
train take the proper line, and if one train arrives a little too
early for the passing, the conductor loosens his cluteh and brings
his train to a standstill until the other train has gone by. He
can then proceed along the main road till it becomes necessaiy to
cross a second train.
(j9) Two roads formed by three rails with one or more sidings
for the passing of trains. — One-half of the endless rope (Fig. 420)
Fig. 420.
lies in the middle of one track, and the other in the middle cS the
other track. The trains pass as they did in the previous sj'stem ;
but there is the advantage that no points are required.
(y) Two entirely separate lines of rails. — In this case (Fig. 421)
no intermediate sidings or points are necessary, for each train has
its own line, and the services of the conductor can be dispensed
with.
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HATTLAGE OR TRANSPORT. 371
In making a choice between these varioue methods, much
depends on the nature of the roads. At some minee it may
be dilficult to keep a rood open of the width neceesaiy for
two separate lines of rails, or indeed for one; so that a system
which can be worked by a single line with occasional sidings will
be preferred. Besides, it may be necessary to introduce mechanical
haulage into a mine laid out originally for horse traffic, and the
expense of making a second road might be fatal to a double-line
system, in spite <^ its manifest advantages.
Fifl. 421,
iv. Endless Chain. — This may be looked upon as a variety
«f the' previous system, a chain being substituted for the rope.
The chain is usually made to ride upon the waggons, and as
«aoh link lies in a plane at right angles to that of its neigh-
bour, it is easy to devise a wmple catch or clip. A common
-one is a bar with a fork at the top, which is attached to one
«nd of the waggon. The waggon is pushed under the chain, which
is sagging down a little, so that a link lying vertically drops into
the fork ; the next link will catch against the dip and set the
waggon in motion. On arriving at the terminus the chain is
njsed by a pulley, and so lifted out of the fork. The waggons
are attached singly.
V. Eleotrio Bailways. — In the previous four cases we
have been dealing with the transmission of power by a moving
rope or chain, we now come to a totally different solution of the
problem — viz., the transmission of power by a wire or wires to a
motor which runs on a track and draws a train of cars after it.
As an example * of an electric railway, I may take one which
has been running for some years at the Neu-Stassfurt mine,
where potassium salts and rock salt are the object of the workings.
The underground railway runs for a distance of nearly 1000 yards
'(900 m.), along the strike of the deposit ; a cable is brought down
the shaft, and there are two insulated conductors hung from the
roof of the level ; one conveys the current to the electric locomotive
by means of a slide, dragged along by a small rope, and the
-other has a similar slide for the return. The road in this case is
perfectly horizontal, and the locomotive draws a train made up
of 30 waggons. An empty waggon weighs 400 kil,, and takes a
load of 750 kil. i 20 full waggons make up therefore a total
weight of 23 tons. The locomotive weighs 2'i tons, consequently
the total weight of the train is about 25 tons. The steam
«ngine for driving the dynamo at the surface is of about 20
• HS. notes and B. ttnd h. Zeilung, 18S8, p. 300.
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37* ORE AND STONE-MINING.
horse-power. The locomotive ib 3 feet J inch vride by 4 feet 1 1
inches high, and 8 feet 9 inchee long between the buffers (930 mm.
by 1500 mm. by 3670 mm.) and the centres of the ajdes are
i8j inches (480 nun.) apart. The gauge of the road is 34J inohea
(€28 mm.), and the diameter of the driving wheels 13} inchee
(350 mm.). The locomotive is made alike at both ends, with a
seat for the driver, so that he can travel in either direction, with-
out having to turn it round. It takes a train £ve minutes to ran
the 900 metres.
The cost compares favourably with that required for tiamming
by men or horses, and in 1888 the figures given were as follows :
—
E]«lrie B.UWT.
HoTMt. 1 Um. 1
Costofbanlagspertont
per kilometre . /
PItapIt*.
rtamis,.
34-ao
Speaking rou^ly these figures are i Jij. per ton per kilometre
for the electric railway, i^d. for horses, and 4d. for men.
Comparing the electric railway with horse traffic, there are
other advantages besides that of cost. The mine is kept much
sweeter and cleaner, from the absence of the droppings of the
horses, and ia this particular case, the animals would suffer in
their hoofs, from constantly walking in the damp salt.
The Neu-Stasafurt line ia not working under the most favour-
able conditions for economy, because it cannot be kept fully
employed ; and considering the rapid strides which have been made
during the last few years in electric transmission, it is certain
that a line put up nowadays would furnish more favourable
results. The line shown by Messrs. Siemens and Halske, at the
late Frankfort Exhibition, had a dngle wire hung from the roof
of the level, and the current was brought down to the motor on
the locomotive by a running pulley held by a balanced arm, which
ensured contact, although the distance between the wire and the
locomotive was not always exactly the same. The return current
travelled along the rails.
At Greenside mine in Westmoreland, there are two wii-es along
the roof of the level, one for bringing the current to the electric
locomotive and the other for the return.
VI. COITVEYAITCE BY BOATS.— This is a very excep-
tional method of conveying mineral underground at mines; bat
it needs mention to make the subject complete.
In this country there is an adit level at the Tankerville
and Bog mines in Shropshire, known as the " Boat level,"
because the ore was carried in boats to its mouth, & distance in
some places of i j miles. As the adit had been driven with too
great a fall originally, it was necessary to have small locks under-
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HAULAGE OR TRANSPORT. 373
ground, and so subdivide the whole length into several parte, one
slightly above the other. This level now serves simply as a
drainage tunnel.
At the Dorothea AUne, near Olausthal in the Hartz, there is a
level more than 400 jrards below the surface, along which there
was at one time a large amount of traffic by boats. The level is
10 feet high, by 7 feet wide, with 5 feet of water in the bottom.
The boate used on this underground canal were about 31 feet
long, 4^ feet wide outside, and 3 feet deep. The part used for
holding the ore had a capacity of about zio cubic feet ; the load
was 5 or 6 tons of ore, and a full load would bring the edge
of the boat within 6 inches of the water. The boat was
propelled by the men, who pushed with their feet against the roof
of the level.
Transport arove Oroitnd.
In commencing this chapter I said that it would be convenient
in this plaoe to take the subject of conveyance of mineral above
ground, though, strictly spealdng, it would not come until after the
conEdderation of metfaodsof raising ore and rubbish to the surface.
This part of the subject must be treated in a somewhat summary
maonor for want of space, and also for tbe reason that much that
has been said about underground traffic will apply in the case of
conveyance above gronod, indeed the same heads may be taken,
with the addition of a seventh — transport by afe'rial ropeways.
1. Sboota made of timber, with the wearing parte protected by
iron, can be applied in places where there is a sufficient amount of
fall. In a hilly countiy it may sometimes be worth while sinking
a shaft solely for the purpose c^ using it as a means of dropping
ore to a lower level.
2. Flow along Pipes is made use of on a very extensive scale
for the transport of natural gas, petroleum and brine.
The Annual Report of the Phikdelphia Company, one of the six
companies supplying Pittsburg, shows that in the year 1S85 it had
331 miles of mains and distributdng pipes, which brought in the
natural gas from distances of 22 to 24 miles; at that ume it was
estimated that there were at least 500 miles of pipes coming into
the city. The mains vary in diameter from 3 inches to 30
inches, the largest sixes being made of caat-iron and the others of
wrougbt-iron. There are more pipes of 8 inches in diameter
than of any other size, and the mains are made to increase in
diameter as they approach the city, in order to reduce the
pressure of tbe gas. Many of the wells when shut would have a
preBBure of 500* lbs. per square inch, and even when the preesmre
IS far lower than this, it is necessary to reduce it in order to
prevent leakage, which means not only diminished profits to the
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374 ORE AND STONE-MIWING.
compuiy, but aim danger to the oonsumw. In the town thft
preesute nowhen exceeds 13 lbs., and in many of the mains it is
not mora than 6 or 8 lbs,, whilst in the low pressure mains it is
only 4 or 5 ois. per square inch.
Another case of conveyance of gas hy pipes is saen at the bore-
holes f nmifihing carbonic acid gas in Oennany ; under its natural
pressure the gas flown through wrought-iron pipes, either to the
works where it is compressed into the liquid state, or to those
whera it is utilised for the manufacture of white lead.
Crude petroleam, which either rises naturally to the sur&ce or
in pumped up, has to be refined before it can be utilised com-
mercially, and it has been found convenient in many districts to
send the oil to the retineriee by pipe-linps.* Pumps are employed
for forcing the oil through the long lines of pipes, as there is no
natural pressure in this case. The Unit«d Pipe-lines Company in
America had, in 1886, "over 4000 miles of piping and 500
reeervoirs, each holding from 20,000 to 30,000 barrels," t and
probably now there are more than 5000 muee of pipe-linee in the
United States,
The pipe-line from the LimaJ oil district of Ohio to Chicago is
3 10 miies long; the pipes are 8 inches in diameter, and each
piece 33 feet long. The cost of the pipes alone was estimated to
be $7000 per mile, and the total cost of the undertaking, in-
cluding the pumps and reeervoirs, $3,250,000.
Another cd the great American pipe lines § connects Clean in
the Bradford oil-Seld with New York City. It consists of two
lines of 6-inch pipes, more than 300 miles in length, and it i&
divided into 11 separate sections. At each station there are two
tanks and a pump ; when one tank is receiving oil, the other is
supplying it to the pump for transmission to the next station
further east, a week being required to complete the journey. As
the lines of pipes follow the irregularities of the surface, amgle
pumping power has to be provided. One of the Worthington
pumps II on this line exerts a pressure of 900 Ibe. per square
inch, and is capable of delivering 1,500,000 ^lons in 34 hours.
Mr. Marvin also mentions a pipe-line at the Burmese oil-fields
made of lacquered bamboos, for taking the oil from the wells to
the river. Modest as this line appears compared with the great
undertakings just described, it is nevertheless an advance upcai
the old plan of putting the petroleum into earthen jars, and
carting it.
In this country, brine is sent by pipe-lines from the wells
* Bedwood, "Petrolentn and Its Prodnou." — ■/burn, Sae. Arit, zxziv.
1886, p. 832; aod ■' OantoT Lectures," pablUhed Bspaiatel;, p. 30.
t 7%e TEnuf, 39tb September, 1S86.
I Enginterintj, »ol. iIt. i888, p. 439-
i C. Harrin, " England ai a FetTDlenm Power," London, 1887, p. 19.
Q Eng. Jtin. Jout^ vol. 11, 1891, p. 745.
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HAUIAOE OR TBANSPOBT. 375
to oonTemient places for evaporation or to alkali works, where
it is used in making carbonate of soda by the Solvay process.
Lastly, it has been suggested that the solution of the " <»liche," or
raw nitrate of soda, ^ould be sent down in pipes to the coast
for evaporation, instead of performing this process in the arid
desert in the neighbourhood of the diggings.
The flow of mineral in suspension in water along troughs
(laundert), or channels made in the ground, or pipes, is a process
which may be seen on the dressing-floors at m«talli^rous and other
mines, as well as at china clay works. At the Mechemich lead
mines the waste from the preliminary dressing-floors is forced by
plunger-pumps through a large pipe to pyramidal boxes, in
which the water is separated from the sand, so that it may be
used over again.
Though not a true flow, I may here mention the conveyance of
a mineral for short distances by revolving screws in troughs
("screw conveyors"), which serve to transport a mineral from
one part of a factory or dressing-floors to another.
3. Human Iiaboor. — In mountainous districts where the
inhabitants are accustomed to carry their provisions, their hay
or other agricultural produce upon their backs, it is not unnatural
to find ore transported in the same way from the mine to the
dressing-works. Sot many years ago, gold ore was regularly
carried to the little amalgamating mills in the Italian Alps on
women's backs. The ordinary load for a woman down bill was
100 lbs. (45 kil.). If the woman took tools or materials up
hiU, the load was naturally less, and amounted to about 75 lbs.
(34 kil.). The ore was carried in a basket or creel {acivera), an
appliance to which every peasant-girl had been accustomed from
eariy youth.
Ore may be moved from one part of the dressing-floors to another
by hand-barrows. These are merely rectangular trays or boxes,
with a pair of handles in front and a pair behind. The band-
barrow requires two persons to carry it (-Fig. 611).
Carriage on the head is met with in some countries.
4. ConTeyanoe by Sledgea. — Sledges drawn by men or horses
still survive in some hilly districts. Even in Wales at the present
day, manganese ore is sometimes brought down from the mine to
the near^ cart-road in this primitive fashion. But it is a toil-
some and unsatisfactory method of transport, and justifiable only
in the case of trials, which have not yet proved a sufiicient amount
of ore to warrant the construction of a tramway or a ropeway.
5. It is by wheelod oonTeyEUioea that minerals are most
commonly transferred from one part of a mine to another, or
from the mine to a railway or port of shipment. Wheelbarrows
are applicable for distances measured by yards, such as one may
have on dressing-floors, and carts are sometimes the only available
means of transport for one or two hundred miles ; but the trafSc
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376 ORE AND STONE-MINING.
should be conducted in some cheaper fashion, b; rulways tor
iostance, as boob aa possible.
It is not necessary to so over all the old grotmd with regard to
rails, Bleepers, points and crosaingB ; suffice it to say that though
the surface railway resembles the underground one, it is generally
bettor kept ; firet, because ite defects are more palpable to every
one by daylight than when seen by the glimmer of a candle, and
secondly, beoiuse there are fewer difficulties in laying it properly
and keeping it in order.
At the surface as well as underground we hat-e self-acting
inclines, and traction by looomotivee and ropes.
Self-acting inclines stand the miner in good stead in hilly
countries. There are either two entirely separate roads, one for
the full waggon going down and the other for the empty which is
being brought up, or there are three rails with a pass-by in the
middle, or even a single road, except at the pass-by. The incline
is worked by a drum at the top, placed most commonly on a
horizontal axis, and of course provided with a brake.
As examples of large inclines, I may refer to those erected
bythe"Boci^ Franco-beige des Mines de Somorroetro," ♦ for
bringing down iron ore to their railway, which then conveys it to
the port of Bilbao. The tower of the two planes is 737 yards
(674 m.) long, with an average Inclination of 30°, the maximum
inclination being 36° near the top. It is worked by steel wire
ropes i^ inch (3)$ mm.) in diameter, which, are coiled around two
conical drums, united by their babes and having a mean diameter
of 16^ feet {5 m.). In order to regulate the descent of the trains,
the drums are connected by gearing with an air-brake, identical
in principle with the fly of aclock (Fig. 433). It is composed of four
straight vanes made of wood and iron, about 6^ feet (2 m.) wide,
and 16^ feet (5 m.) in diameter outside. Twelve waggons coming
from the mine are coupled together so as to form a train, and
when it starts down Uie incline, the air-brake begins to revolve
and soon develops a considerable amount of resistance as the speed
iDcreases ; the consequence is that the train descends with an
almost uniform velocity. The strap-brake on the drum simply
serves to moderate the speed if necessary and to stop the tram ;
but in no case ia much power required to work it. The train
makes a journey in three minutes, and it takes three minutes to
make up and couple on a train ; therefore there is one train
every six minutes, and as each waggon contains two tons, the
quantity delivered by each train is 34 tons, or with ten trains an
hour the quantity per day of ten houni will be 3400 tons. By
increasing the number of waggons in each train, the day's work
* Mivontion UnivtrniU de /S8g. Note sur VEx^onUon dt la SoeUli
FranaHtdge da Mina de Somarrottro en iSSg. Paiis, 1889, p. 11. Lei
Orartdei vtinee de Targan. Anfrast, 1889, p. 50. Forget et Ateiiert de Qm-
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HAULAGE OR TRANSPORT.
Fig. 412.
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3;8 ORE AND BTONE-MINIHG.
may be run up to 2600 tons. The fan-regulator has the advan-
tage of saving the wear of the ordinary stoip-brakes and of
rendering the speed uniform. If nothing but a strap-biake was
used, there wouJdbaa very great amount of friction, which might
cause the wooden shoes to take fire ; in any case it would
throw a great strain upon the machineiy, and involve the risk
of a serious accident if it happened to break. The fan-
regulators avoid all these difficulties ; but th«y must be made
veiy strong, as they have to counteract a considerable amount of
tiit vha—At the particular incline mentioned no less than 428
horse-power. I have dwelt somewhat upon this fan-regulator,
as it has been found extremely serviceable at Somorrostro, though
little known elsewhere.
Locomotives burning coal can be used without inconvenience,
and efiect a great saving in most places, when compared with
horse traffic. At the Festiniog slate mines, small locomotives
running on a track with a 33j-inoh gauge are employed for
drawing trains of rubbish to the tips ; the total weight of a toain
may be as much as 80 tons. Ae the men who are removing
rubbish from the underground or surface workings are foid by
the ton, the loads have to be weighed. When the tr^ns are
drawn by a horse, it is necessary to stop each time a waggon is
brought on to the weigh-bridge ; but when the locomotive is used,
the train runs so smoothly that the waggons can be weighed
during their passage, without any halts being made. This is
a small advantage it is true, but it saves time and consequently
money, and should therefore be noticed.
The endless rope and the endless chain conveying single
wafn^ns at stated intervals are both in favour, either for trana-
portmg the valuable mineral to any required spot, or for taking
the waste to the tip or " dump."
An example of the former system may be seen at the De
Beers* diamond mine, Booth Africa, where the gem-bearing rock
has to be exposed to the action of the atmosphere foreome months
in order to make it crumble away and become ready for the pro-
cess of washing. Large areas have to be covered with the "blue,"
and cheap haulage is a matter of importance. The depositing
floors commence at a point a mile from the mine and extend
for three miles to the east and one mile to the west. The main
line is three miles in length and it has two branches, one a mile
long, and the other three-quarters of a mile long. The rope is
driven by a horizontal engine, with two cylinders, each 14 inches
in diameter, and having a stroke of 3 feet. It is i inch in
diameter and, as is very commonly the case elsewhere, it has an
iron instead of a hempen core, in order to prevent a reduction at
Second Annual BepoHfor Iht
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HACXAGE OR TRANSPORT. 37?
section when it is subjected to continued tension. It is carried
on the steel trucke, which can be tipped on either side, as the body
ia supported on two trunnions (H, Fig. 442). The device for
attaching the rope to the waggon is very simple ; the rope lies
in a foi^ or " jockey," which is slightly out of the direct line of
traction. The jockey is free to turn in a socket on the truck,
anO the slight bend given to the rope is sufficient to afford the
necessary grip, even in going up an incline of i in 30. If the
" blue " has to be depoeited at a point nearer the mine than the
terminus, the part of the rope beyond the place where the waggons
are taken off is supported by pulleya
Horses are employed to draw the trucks from the main rope
haulage lines to the places on the floors where they have to be
tipped.
The endless chain has been chosen for bringing down the ore
from some of the mines of the Bomorroatro Company,* in a part
where self-acting inclines cannot be used because there is not a
descent all the way. A second reason for adopting this system
was the fact that It admits of considerable changes in the amount
of tra£Sc, by altering the speed of the chain and the distance
between two successive trucks. It further allows branch lines
to be taken off from the main one. At Somorrostro there are
in all very nearly two miles (3000 m.) of endless chain haulage.
The greatest difference of level between the highest point at
the Sol mine and the terminus at the station of Cadegal is 8oz
feet (344'6o m.), and on one part of the line tne gradient is as
high as 39*5 per 100 or 1 in 3*4. The fall, is so great thai the
ch^iin requires no power but gravity to work it ; in fact, it is
necessary to use brakes to oppose the vm viva. Strap-brakes are
employed in the pame manner as they are on the inclines just
described, solely for the purpose of stopping the chain. The danger
of depending entirely upon such brakes for working inclines has
already been pointed out, and a uniform speed is maintained by
affixing fan -regulators working in water. They are chosen in this
case in preference to the fans working in air, because the latter
must revolve at a great velocity in order to be efficient, and there-
fore could not be applied to the slow chain haulage without gearing,
which would introduce complications. These hydraulic governors
are tike the air-regulators in principle, except that the blades ai-e
immersed in water; the speed of the chain can be adjusted with
the greatest nicety by altering the quantity of waler in the tank
in which the blades work, and so introducing the amount of
resistance required.
The usual speed at which the chain is run is 5 feet (1-5 m.) per
second, but it can be raised to 6 feet 6 inches. The chJain is made
of |-inch (33 mm.) iron, which corresponds to about 19-^ lbs. per
* £xpotUion UnivertciU de 18S9. Op. cil., p. 15.
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38o ORE AND STOHE-MIHING.
jrard (9*826 kil. per metre). The last sectioD, however, has harder
work, and the chain is of i-inch iron. (36 nun.) and weighs 38
Ibe. per yard (14 kil. per metre). Each waggon holds 17} cwt.
(900 kil.) of ore, and when the wagons are arranged 27 yards
(35-z m.) apart, the chain haulage is capable of transportirig 2500
to 2600 tons of ore a day, in addition to a certain amount cd
iiibbish which ia tipped before arriTing at the port.
6. OonTeyanoe of Hlneral by Boats from one port of a
mine to another ia exceptional ; but transport by canal or sea
to the consumer is common, and is chosen whenever available
on account of its comparative cheapnees. It ia of the utmost
importance when dealing with large quantities of mineral to have
cheap and rapid methods of shipping it. At Huelva, the shipping
port of the Rio Tinto minee, the trains of ore are drawn on
to a part of the pier which has just enough inclination to make
a truck run down of itself. A workman then uncouples a
truck and allows it to run opposite a shoot, which leads to the
hold of the vessel lying alongside the pier. The truck is emptied
by opening the bottom and letting the contents drop into the
mouth of the shoot. The bottom is then closed and the truck is
allowed to run on a little further, when it is shunted back on to
a side line, and made to join the train of empties ready to be
drawn back to the mine. After the locomotive has once hauled a
train on to the proper part of the pier, the discharge of its
contents into the ship proceeds very rapidly and requires the
attendance of only one man.
The arrangemenlf are so perfect that 500 tons can easily be
loaded in an hour, but naturally a good deal of time is lost in
shifting the steamers and berthing tfaem. The greatest unount of
work in loading at Huelva pier has been a litue over 3000 tons
in a single day. A steamer has been known to come into Huelva
harbour by one tide, and leave by the next with a cargo of 1500
tons of ore.
The Bomorrostro Company loads its iron ore at Bilbao in a
similar manner. The Company has three wharves, at each of
which 3000 tons can be shipped in a day ; indeed a ship of 1490
tons has been loaded in six hours.
7. ASrlal Bopeways. — These ropeways may be divided into
five classes '.
a. Bingle sapportiue rope, with o:
b. Bodless lope, which ia t'
at the aame time.
e. Two Bnpportiiig ropes and an eDiIleia rope for hauling the load.
d. Double endless traTelUiig rope or chain.
c. Telpherage line.
a. Lines erected on the first of these principles may be seen in
hilly countries. An iron or steel wire rope is stretched across a
valley, and forms the rail supporting the load, which is put into
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HAULAGE OB TKANSPOET. 381
a sack and hung on by a grooved pulley. If the beigbts of the
departure and receiving etationa are properly arranged, the load
on going down the slope acquires enough momentum to bring it
np to the station on the other side, without rnshing in too
violently. The objection to this system ia that the socks and the
pulleys have to be carried back by men or women, but it has the
merit of simplicity and cheapness. By the addition of a small
hauling rope on a drum, the method is available for steep moon-
tain Bides ; the load is lowered with use of the brake, and liie drum
is worked to diaw up the empties along the supporting rope.
b. In this system there is SrU endless rope, supported by pulleys
on strong wooden or iron posts placed at suitable intervals, which
is set in motion by Einy available source of power. Suspended from
the rope are the buckets or other vessels in which the mineral is
carried. The buckets maybe detachable at pleasure or they may be
fixed. The former plan is the one brought out by Hodgson in i86q.
The bucket or other receptacle is suspended by an iron hanger
from a grooved block of wood which rests upon the rope. The
carrying block has a, spindle with a small grooved pulley, which
can be made to run upon a rail at each terminus and so let the
rope move on without the load. The bucket is filled from a shoot
or hopper while hanging on the rail at the loading terminus. A
workman then pushes it along tbe rail until the carrying block
is taken up by the rope, which is always in motion ; the load now
travels along suspended from the rope, the carriers being con-
structed BO as to pass over the pulleys. On reaching the unload-
ing terminus, the carrying block is again shunted on to a rail, and
the bucket is tipped by lifting up the catch which had kept it from
turning about pivots ; after having been put into position, it is
brought round to the point where tbe rope, after passing round a
terminal pulley, is about to begin its jonmey back to the loading
station. Here it is shunted on to the rope and travels along
One great disadvantage of this system, in the case of steep in-
clines, is that the carriers may slip upon the rope, and that the
loads either fall off or do damage in some other way. To over-
come this difficulty, some of the constructors of atrial ropeways
attach the loads to a dip which is tightly fixed to the rope. The
dip must be of such a nature that it will pass the supporting
sheaves or pulleys. When the inclinatioa is sufEcient, an aerial
line of this deecriptioD will work automatically, the weight of the
full loads being enough to draw up the empties.
e. The third system haa two fixed ropes, which serve as aerial
rails and act solely as supports, and an endless travelling rope,
to which the loads ore made fast at pleasure. It resembles,
therefore, the endless rope haulage, of which mention has been
made for underground work, save that the rails are above the
load instead of being below it.
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38a ORE AKD STONE-MINING.
Ropeways working upon this pl&n have been perfected of late
years by Otto and by Bleichert in Germany, where they are
oommoner than in this country. They are constructed for distances
of from 3 to 8 or even lo miles, with a carrying capacity of 6od to
jtoo tons per day of lo hours. The separate loads may vary frfwa
J cwt. to r ton each.
The points to be considered are :
Carrying rope and vesfeL
FostB or standardE.
HaDling rope and attaobmsnts.
TerminaU and their shunting arrangementB.
The kind of cable used on the most recent lines erected on the
Otto system * is that known as " locked coil wire rope," the con-
struction of which is explained in the next chapter (Fig. 451). It
has the advantage of presenting a perfectly smooth surface, ad-
mirably adapted for tike running of the grooved pulleys by which
the load is suspended. The vessel in which the mineral is conveyed
may be any convenient form of bucket
Fia. 433. or box, supported by pivots around
which it can be essily tipped, or the
actual mine-waggons may be slung up
and the ore carried in them.
Each box, bucket, or waggon, is at-
tached to a hanger suspended from a
spindle placed midway between two
grooved puUeys or wheels, which rest
on the rope (Fig. 423).
The posts or standards ai'e constructed
of wood or iron, sometimes with two,
and sometimes with four legs, suitably
stiflened by braces and held in position
by guyropesorrod8(FigB. 424aod42s).
The four-legged standards are used for
heavy loads or long spans. The distance
between the standards varies according
to the natureof the country,and is often
about 30 to 60 yards ; but where the
country is much broken by ravines, these short spans are unat-
tainable without standards of an impracticable height, and the
cable is then made to stretch across very long intervals without
intermediate supports. Spans of 550 yards (500 m.) are not
unknown.
The hauling rope must be very flexible, and is made of fine steel
wire with a hempen core. The mode of attachment of the load
vai-iee with the gradient of the line. If the gradient is less than
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HAULAGE OR TKANSPORT,
383
I in 6, the amount of friction necessary for gripping the rope
tightly can be obtained by bringing it between two flat iron
diacs and clamping them together with a ticrew. One of these
discs is rigidly attached to the hanger, and the tigbtening screw
of the other can be loosened automatically by providing it with
a projecting lever, which comes in contact with a stop at the
terminus.
If the gradient is between i in 6 and i in 3, the discs are made
Fig. 435.
with corrugated instead of smooth surfaces. When the gradient
exceeds i in 3, another device has to be employed ; projecting
knobs ore inserted into the rope at regular intervals, and on
meeting with properly arranged stops upon the loads they cause
them to travel along. Figs. 426, 427 and 428 show the details
of the arrangement.
Each terminus is provided with an iron rail which is fixed
BO as to meet the rope where the buckets have to be
loaded or unloaded ; by suitably arranging the end of the
rail, the load passes quite smoothly from it to the rope and vice
verad.
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384 ORE AND STONE-MINING.
An example of one of the CHto ropeways is given in Big. 439,
which ill a section of the line put up for the Bheba Gold Hiuiug
Company, Limited, Barberton ; it is 2 J (4-4 HI.) milee long, and
will carry 150 tons per day of 10 hours. The maxii
is I in 16, and the greatest span 1480 feet (451 m.).
Fig. 419.
A line erected in Southern Spain for carrying iron ore is 9*69
mUes (15*6 kil.), long, divided into four independent sectiong.
The greatest span is 91S feet (280 m.), but on an average the sup-
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HAXJLAGE OR TRiNSPORT. 385
porting poste are only 44 yards (40 m.) apart. The haviling rope
is made to travel at the rate c^ 100 yards (90 m.) a minute,
and deliver two buokete, each containing 7 cwt. (350 kil) in that
time. This means a carrying capacity of 1200 buckets c^ 420
tons per day <^ 10 hours. The line has also been worked with
two shifts of S hours each, and has transported 900 tons in that
time. The total cost of this line, which was surveyed, erected
in a very difficult country, and ready to start in ten months,
was ^26,000; and it has been worked at a cost of it.^d. per ton,
whi(^ includes all that is spent for labour, maintenance and
repairs.
At the Menzel colliery in Upper Silesia, 500 to 700 tons of
coal are carried in ten hours a distance of i'6 miles, for i\d. per
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386 ORE AND STONE-MINING.
ton per mile, including wages, repairs, interest on capital and
depreciatioii of plant. Fig. 430 shows part of the line at Oattee-
rngen coUieiy, Upper Silesia.*
A line carrying iron ore in Luxembourg is 3 milee long, and
transports 300 tons of iron ore in 10 hours at a. cost, again in-
cluding all expenses — vis., wages, repairs, interest on capital, and
depreciation cl plant, of 4^ per ton, or i^d. per ton per mile.
d and e. Bopeways worked dj these systems are rare.
* "OttoPatent Ropsm;.'— 7lc£njFi>un-. vol. Ixrfi. 1889, p. 115.
.vGooglf
CHAPTER VIII.
EOISTIKO OB WINDING.
HotoTB, drains, and poUey-framea. — Bopee, ohaliu, uid attBChmeuts, —
Kibbles, skips, and cages. — Eepa, guides, agnaia. — Safety appliancea,
detachii^-hooki, safety-oatahea, antomatio stopping gear— nieomatlo
hoiBtiug.
Bs hoisting is meant raimng the miDersls from the underground
workings to the surface. In speaking of the subject generally,
it is more correct to say hoisting than winding, because this
latter term implies the use of the rope, which is not quite
uniTorsal. As already explained ia the last chapter, there is do
clear line of demarcation between haulage and winding; In
the typical case of a vertical shaft and a nearly horizontal level,
it is easy to make the distinction ; but when the mineral is
drawn up through inchnes, the name given to the process
depends upon loi^ custom. Thus, part of the shaft at a Cornish
tin mine is incUned &t an angle of only 15^° from the horizontal,
and nevertheless the work of drawing up the ore is always called
winding.
In B. few districts carriage on the back still survives; in
Sicily, for instance, much of the sulphur rock is brought to
the surface by boys on their bacb^ up rough paths, or steps
«ut in the ground. As lately as ten years ago, I found sl^
being brought up on the back in the Moselle district. In
Mexico and in China, too, the same method is pursued in
some silver and other minee. However, this barbarous mode
of raising mineral ia simply mentioned for the purpose of con-
demning it.
The regulsr method of bringing a mineral to the surface is to
dr«w it up a shaft or an incline by metms of a rope. The subject
is such a wide one that it must be treated under different headings
as follows: (i) Motors, drums and pulley-frames; (z) Bope,
or chain ; attachments of the rope ; ( 3) Receptacle for the mineral
or waste rock ; (4) Other indispensable appliances, guides, signals,
kejH ; (5) Safety appliances.
I. MOTORS, DBUUS, AND PULLBT-FRAUES.—
Moton — As in other departments of mining, the motor empli^ed
may be worked by animal power, or by an engine driven by
water, steam, compressed air, petroleum or electricity.
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388 ORE AND STOKE-MINING.
(u) Animal Fotoer. — ^The simplest cootrivaDce for winding is »
pulley supported by some suitable frame above the shaft ; a bucket
is attjiched to the end of a rope hanging down the shaft, whilst tlie
other end, passing over the pulley, is drawn by men or women :
they simply walk away from the shaft and haul up the bucket.
Oil wella are sunk in Burmah by this primitive method of
hoiBting.
The tiBual method of applying human power is by a windlass.
This well-known appliance consists of a wooden cylinder, about
eight inches in diameter, provided with two iron handles and
supported by two upright posts which are suitably stayed. A
sliding bar, which can be drawn out either above or below the
cylinder, serves to hold one of the bandies, when required.
In this country, the ordinary windlass ig used for shallow
sinkings of twenty, thirty, or forty yards in depth, such as are
made in commencing work at a mine, or in eSbctiag a communi-
cation between two levels ; but in countries where mining is
less advanced, and where labour is cheaper, the windlass may
form the sole means for hoisting from depths of a hundred and
even two hundred yards. Thus, for instance, at Boryslaw, in
Galicia, it is reckoned that six or seven thousand shafts have
been sunk during the last thirty years, for the purpose of working
ozokerite, to an average depth of one hundred yards, by human
labour ; four, five, and even six men and women may be seen
working the Boryslaw windlaes. In the neigbbouring country of
Boumania, oil wells are sunk in like manner. The windlass is used
either with one or two buckets ; in the latter case the labour
is lightened, for the weight of the empty bucket going down
balances the dead weight of the bucket coming np with a load of
As a rule too little attention is paid to the state of the axles
and bearings. Windlasses, like other machines, cannot be worked
with economy unless means are taken to prevent unnecessary
friction, which is sure to arise nnlees the axles and bearings
aro kept perfectly true ; this fact should be specially borne in
mind when the mine-owner is emfJc^ing expensive human
power.
The capstan is an unusual form of winding machine at mines ;
it differs from the windlass by having ite cylinder vertical As an
instance of its use, I may mention the little underground quames
at Swanage in Dorsetshire, where blocks of stone are drawn
up inclines by means of capstans turned with bars, after the
manner of those used on board ship.
When a horse is employed in the place of men, the bucket,
attached to a rope passing over a pulley, is sometimes drawn up
by making the animal walk away from the shaft. The framework
and pulley constitute what is called a whipaiderry.
Animal power is nsnally applied \)y means of a machine called
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HOISTING OR WINDING. 389
a. hoarse- whim. It may be looked upon as & gigantic capetan,
worked b; horses, molea, or donkeye. It conaiBts of aa upright
axle, usually of timber, supported at the bottom by ao iron pin
or pivot, which works in a hole in a large stone, forming a primi-
tiye foot-block. A horizontal beam, known as the driving beam,
is attached to the axle, and above it comes a hollow wooden
cylinder or drum, around which the rope is coiled, proper project'
ing horns or flaogee being provided to prevent it from slipping
off.
I^e other end of the axle works in an iron socket, carried
by a great horizontal beam, known as the span-beam, which is
supported by two legs. In this country the horse-whim is not
roofed over, and it forms a promineot feature in many mining
districts; where the weather is more severe, a bouse becomes
necessary. The winding rope is coiled several times around the
drum, and both ends, after passing ovBr pulleys, hang down the
shaft ; when the horse walks round, one bucket is raised and
the other lowered.
Before the introduction of steam, the horse-whim was a very
important means of winding ; and in countries where water-
power is lacking, coal dear, and fodder cheap, it still performs very
useful services. As many as six to eight horses may be harnessed
to a horse-whim for the purpose of working it.
(b) Water. — I will now pa^ on to the engines worked by water,
stmm, compressed air, petroleum, or electricity.
When the wat«r-whee1 is used for hoisting, it is necessary to
have means of reversing the motion, in order to raise or lower
the rope at pleasure. Two methods may be employed : A
double wheel with the buckets fixed in opposite directions ; a
single wheel provided with suitable gearing or belts. The double
wheel is frequently seen underground in Uermany ; it has sluices
{hate/tea) which will turn the water on to either side, and there is
a brake for controlling the motion. The winding-drum is placed
on the shaft of the water-wheel, and according as the water is
turned on to the right-hand or to the left-hand side, the wheel
revolves one way or the other.
When gearing is employed, a bevel-wheel upon the shaft of the
water-wheel drives a pair of bevel-wheels, facing each other, which
run loose upon the sluift of the drum. By means of a suitable
clutch either of them can be brought into firm connection with
the drum-shaft, and so made to drive it in the required direc-
tion.
Pig. 431 shows the method adopted at Great West Yan Mine
in Oftrdiganshire by Messrs. TJrquhardt and Small. A, Girard
turbine ; B, belt driving the shaft of two pulleys C D ; E and F,
pulleys loose upon the shaft ; G, clutch; H, handle working clutch;
I,piniondrivingspur-wbeel on drum J J ; K, brake strap ; L, pia
connected, when required, to "bob " of pumps. The belt from C
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390
OBK AND STONE-MINING.
FlO. 431.
to £ is Btraight, and that from D to F ia crossed ; therefore the
two poUeys £ and F are alirays revolving in opposite directtoDO.
According aa E or F ia made fast to the ahaf t by the clatch G,
the pinion I toma the drum one way or the other.
(c) Steam. — 8t«am-engiuee em-
I^oyed for winding have osaatlj
two (r^lindera, either vertical or
horizontal; the latter are preferred.
In some mining districtB, notably
in Cornwall, one finds a single
vertical cylinder working a beam
by which motion is communicated
to a fly-wheel; but for rapid work
it is necessary to have more com-
mand of the engine than can be
furnished by a machine of this
kind.
It was the fashion at one time
to put a pinion upon the cranlc-
shaft and a spur-wheel upon the
drum shaft; nowadays for quick
winding the drum b placed upon
the same shaft as the cranks. This
is called working on the first motion,
whereas if gearing is used the
method is said to be on the second
motion. In any case the engine
must be provided with an adequate
brake, and where the drum is
worked by gearing, it is necessaiy
to have a brake upon the drum
shaft, because otherwise there
would be no means of arresting
the descent of the load in case of
fracture of some of the cogs.
Although many winding engines
work without expansion, automatic
expansion gear is common, and
some of the engines are arranged
BO that the commencement and end
of the run shall be worked with
the full power of the steam, and the middle of the run expan-
sivdy. Compound engines, and indeed triple expansion engines,
have been erected for winding purposes, though the advisability
of employing them is questioned by some mining engineers ;
whUe fully admitting the value of this principle in the case of
engines which are working constantly, such as those used for
pumping, they contend that it is not advisable to comphcats
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HOISTING OK WINDING.
srk, and is being
machm«Ty whiuh is performing very irregular y>
continually stopped and started.
Componnd engiuee have, however, been adopted recently for
winding at Llanbradach CoUiery, near Cardiff, by Mr. Galloway.
the two cylinders on each aids are arranged tandem fashion
(FigB. 432 and 433). A^ high preesure cylinder; B, low pressure
cylinder ; C, drum.
{d) Cony>rested Air, — Oompressed air is largely employed when
the hoisting engine has to be placed undeigronnd, and it is
especially suitable for
sinking intermediate ^'^ *3^
shafts (vjvmes). Com-
pact and handy forms
of engines are supplied
by varioos makers ;
many of them are
similar to the steam
winches osed on board
ship, and consist of
two cylinders driving
a jnnion which works
a spur-wheel placed
upcHi the same sluft as
the drum.
Occasionally, as for
instance at the Long
Tunnel, Walhatla, in
Victoria, aU the hoist-
ing of a mine is done
by a compressed air
engine. The reason for this choice at the Long Tunnel was the
fact that lode was reached by a long adit, in which compreeaed
air appeared to be the most convenient method of transmitting
power from a motor at the surface.
(e) Electricity. — Winding by electricity is as yet in its in-
fancy; but, no doubt, in the course of a few years, we shall
hear more of this convenient method of conveying power to the
place where it is to be used. It is easy to understand that an
electrical motor con be applied to the drum used for winding,
its rapid motion being reduced to a suitable speed by means of
gearing.
DniioB. — A winding drum is usually a mere revolving cylinder,
aronnd which the rope coils itself. It is formed of two centre-
pieces keyed to the shaft, each carrying arms, to which are
attached rings. Supported by these rings are pieces of plank
or plates of iron or steel, which build up a hollow cylinder, the
length and diameter of which depend upon the importance of the
plant. In largo mines one may see drums 20 and even 30 feet in
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39a ORE AND STONE-MINING.
diameter ; with a drum of ao feet, lo revolutioiiB mean coiling or
UQOoiling 309 yards of rope.
A dram constructed for LUnbradach Colliery is a hollow
cylinder 1 7 feet in diameter, and 8 feet wide. In Figs. 434 and
435, A is a oaetriron cantre-piece ; B B are arms made of H-st®^
to which are riveted the croeabarB of channel-iron 0. The skeleton
formed in this way is covered with plates of steel D, | inch thick,
which are fixed with countersunk rivets to T-iron £, where they
meet. F is the flange to prevent the rope from slipping off the
dram, and O the wrought-iron ring upon which the brake
acts. A novelty introduced by Mr. Galloway is the arrange-
ment for keeping a reserve length of rope to supply the lose
fla.434.
caused by snooeBsive re-cappings. Inside the main drum is the
hollow cast-iron cylinder H, capable of turning independently.
When a new rope is put on, 50 yards of it are c^Ied upon
H, the bolts of the clip I are fastened, and the remaindw
is wound round the mam drum. After re-capping the rope
at the end of two months, it is easy to unloose the clip and
draw out what is required. The drum is constructed as light bb
poesible, in order to prevent power from being wasted in starting
and stopping an unnecessarily heavy mass. The shaft is 20 feet
in diameter and 550 yards deep to the first seam of coal intended
to be worked ; but it will be probably made 600 to 630 yards deep
in time. The engine (Fig. 432) is expected to raise 200 tons <^
coal per hour with two mine waggons in each cage, each wagg<m
carrying 2 tons.
Ad objection urged against the plain cylindrical drum is that
it in no way compensates for the change of work required of the
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HOISTDJO OR WINDING. 393
engine during the different phases of the act of winding. To make
this plain, suppose one end of the rope to be at the bottom of the
shaft with the full load attached to it, whilst the other end is at
the top with nothing but an empty cage. On starting, the engine
has to raise not only the weight c^ the load of mineral, but also
the entire weight of the rope hanging down the abaft, and in deep
minee with large cages, this weight is by no means inconsiderable.
In proportion as the full cage is raised, the amount of dead
weight of rope to be lifted becomes lees and lees. Eventually the
full and empty cages meet ; the two portions of the rope then
balance es^h other, and the engine has simply to overcome the
action of gravity upon the mineral; later on the rope of the
empty cage is longer than that of the full one, and assists the
engine in doing its work. At last when the load is nearing the top,
the drum ia feeling the full weight of the rope of the empty cage.
Oonatancy of load is easily obtainable with the cylindrical drum
by the simple expedient of adding a balance rope — that ia to say,
a rope hanging down the shaft with one end attached to the
bottom of each cage. Provided that this rope agrees in weight
with the winding rope, the counterpoising is perfect, for on each
side, in every phase of the ascent or descent, there is always the
same dead weight acting upon the drum. I^iis method is adopted
at Llanbrodach and also at De Beers Mine. The balance rope
often, but not invariably, passes round a pulley at the bottom c^
the abaft.
With the same object in view the drum is made spiral or
conical, or rather of a combination of two such drums united by
their larger bases. Tfae rope is so arranged that the diameter of
the coil increases as the act of winding up proceeds. The load at
the bottom of the pit acts upon the drum shaft with a small
amount of leverage, and its leverage increases as the weight due
to the rope diminJsbes. The reverse condition of a&its exists
with the descending load : it has a large leverage while tb&ce is
only a short length of rope hanging down the shaft, but as the
weight thrown upon the drum increases, so the leverage
diminishes.
Intermediate between the conical and the cylindrical drum is
one which combines the two systems ; the conical end is used
for starting the load from the bottom and the main part of the
operation is performed with the cylindrical surface.
When a flat rope is used instead of a round one, it is convenient,
for the sake of distinction, to speak of the winding cylinder
as a reel or bobbin (Figs. 436 and 437).* It ia provided on
both sides with long radial arms, which serve the sEune purpose
as the horns or flanges in the case of the drum ; th&t is to say,
they pnvent the rope fnmi slipping off sideways.
* Csllon, Leeturu on Mining, vol. iL plate IzL
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394
ORE AND STONE-MININa.
The flat rope coila upon itaelf , and as the winding proceeds the
diameter of the coil increases, if the cage is beong mised, or
decreases if the cage is being let down. In this way there is a
certain compensatmg action similar to that which is obtained
with a spiral drum — in other words, at the moment of starting,
when the lo&d is at the bottom, the smallest amount of leverage
is exerted upon the driving shaft of the reel ; whereas at the end
of the wind, when the load is least, it is exerting the g
leverage.
Fifl.436.
Pulley- Frames. — The framework at the top of the shaft for
anpporting the pullej or pulleys is known by different names. It
is sometimes called the bead-gear, the pit-head frame, or poppet
heads (Cornwall). It may be constructed of timber, iron or steel,
and metal pulley-frames are usually seen nowadays at large mines,
where winding is conducted upon an extensive scale ; at small
mines and also during sinking operations a timber head-gear is
A kind of frame often used is shown by Figs. 438, 439, 440,
from which it will be seen that four large upright posts support
cross-beams A, B, C, D, upon which the pvdleys rest. The frame is
suitably stiffened by struts. Its principal duty is to resist two forces.
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HOISTING OB WINDING. 395
one exerted by the load and rope hmiging down tlie shaft, oad the
other by the rope which is being hatded in by the dram. At a
moment just before the load begins to move the two forces will be
equal, and the direction of their resultant will be a line bisecting
the angle between the two parts of the rope, and passing through
the centre of the pulley. Provision therefore should be made for
resisting this pull, and this is effected by stays, such as are shown
in Figs. 438 and 440, which represent a pulley-frame used fo
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396 ORE AND STONE-MINING.
ginTriTig a shaft Bome 200 yards deep at Halkyn Mine in Hint-
shire. The hackstay may be placed in any position between
710.441.
the bisectrix and a line parallel to the iY>pe going to the
During the sinldng at Halkyn only one bucket was used, and
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HOISTING OR "WINDING.
397
fts this had to hang in the middle of the shaft the poll^ warn
placed between the two beams B and C. Now, the ehaft is used
for winding with two small cages and there are two pulleys, one
between A and B, the other between C and D.
Fig. 441 shows the head-gear erected at the perpendicular "Bock
shaft" of De Beers Miue,* whilst Fig. 443 representfi the arrangft-
ments at the Iodine shaft of the same mine.
The head-sear at both shafts is made of wrought-iron treUis
work. At the Bock shaft the legs and stays are of 3i-inch angle-
iron, I inch thick. The lattice bars are 3^ by g inch ; the total
height from the ground to the centre of the pulleys is 61 feet.
F1Q.443.
-^''1
\
y^
/
J
1
^
i;^i
A,.^
Pullers. — Winding pulleys have to be placed on the pit-head
frame in order to change the direction of the rope.
Nowadays, in all important windings, the pulleys are made from
10 to 15, and even ao feet in diametor, in orderto subject the rope
as little as possible to sharp bendings, which would reduce its life.
The cast-iron boss, or centre, is joined by wrought-iron arms to
a grooved rim also made of cast iron (Fig- 443). In course of
time steel ropes wear away the rim, and to lessen this source of
trouble, the part in which the rope lies may be chilled. The
groove should fit the rope ; for if it is too wide, the rope will
rest upon a small part of its circumference and be liable to be
At some mines pulleys are made with a light rim, which will
not last for more than a year. The object in view is the preven-
tion of wear from rublong. When Uxe speed of the engine is
* Second Annual Beport 0/ Dt Bteri Ctmtolidated Jftn
Tear ending Mareh 31, iSgo, p. 16 and platei 10 and 7.
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398 ORE AND STONi^MININa.
slftckstUDg, the pnlley, in virtue of its momentum, tends to travel
futer thuk the rope, and thereby to grind ita surface. A dimi-
nution in the weight of the rim lessens the momentum, and
therefore reduces the rubbing action. The advantage gained in
this way, is considered sufficient to compensate for the more
frequent changing of the pulleys.
3. BOPE8, CHAIIT8, AKD ATTACHHEirrS.— Bopes.
— Bopee are made of vegetable fibre of some kind, or of iron or
Bio. 443-
steel wire. The vegetable fibres used are hemp and manilla,
which are twisted into yam ; the yams are laid together so as
to form strands, and finally Uie strands are laid together to form
the rope.
For winding by hand, in sinking small intermediate shafts
(toinzes), a hemp-rope, abont J inch in diameter and made up of
three strands, is commonly employed. For heavier work, either
A round rope of larger section ia necessary, or a flat rope formed
l^ sewing together several round ropee.
Iron is very little employed nowadays for making wire ropes
its place has been taken by steel.
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HOISTING OR WINDING. 399
The advantage of uaiiig eteel as compared with iron, is evident
from the f oUoTring figures : *
^
1.
Ib
KbdolWlN.
1
Kind of
Bop*.
ToUlDHfoldrtet
»
BtnwU
Iron .
60
Sjlindrlul
S.387, 124.051
5-S
0-817
120
26.5j9.3a6.190
32-3
o"3S4
120
TapwiHB
S6.rw.a96.3s9
69.898.974,017
261
0198
0-338 EtopeetiUI
'°-|
It must be remarked that the data concerning the last rope
are incomplete, as it was still in use when the paper was written.
At FNbram,t where winding is carried on in perpendicular
shafts, one of which has attained the enormous depth of 3642
feet, the ordinary omdble cast-steel, with a tensile strength of
T20 kilos per sq. mm., was used up to the year 18S5 ; since then
they have employed wire <^ " patent crucible cast steel " or
"extra" or "special crucible cast steel," with a tensile strength
of 180 to 190 kilos per sq. mm. ; the results are most satisfactory,
and the ropee, after having been in use for two and a half years,
Aowed very little sign of wear, and not a single broken wire. The
former ropes, made of ordinary cast steel, lasted on an average
only 36 months.
Winding-ropes are usually made with six strands and a central
core of hemp, each strand bdng made up of
seven wires (Fig. 443a). The core is sometimes TiQ. 443d.
made of wire ; for instance, if the rope has to
work in a very hot shaft, or if it is used for
haulage purposes with clips which require that
the diameter should remain constant. In or-
dinary ropes the "lay" of the strand is like
that of hemp ropee ; that is to say, the reverse
of the lay of Uie rope (Figs. 444 and 445),
Lang has improved the method of manufacture by making the
lay of the strand the same as the lay of the rope ; the wires
are less sharply bent, and present a longer wearing surface.
, " Ueberdie DrahUeilfobrikationin PKbram mltbesocdeier
BOckaiobt anf die DrahUelle tOc die VertioaUorderang." Baiiage m. Out-
Zattchr.f. 3.- «. M.' Wuta, 1S91, p. 8.
+ Uabermann "Anwendang verjOngtaT FSrderseile am gewolmliotiem
nad ans Patent- oder Eitra-TiegelKa£EBtahldraht bei dea (^saen Sohacht-
dM PfihmmBr Rnnrhnnnii " Oat. Ztittchr. f. B.- a. H.- Wt*en,
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400
ORE AND STONE-MINING.
Tbe reeult ie, that wfailet the wires of tn orduiivy rope wear
quickly on tbe crown of the bend and break (f^g. 445), ling's
rope, with its greater wearing surface, has a much longer life.
Figs. 446 and 447 are taken from actual examples of I^n^it
rope before and after use.
Haggle's patent Protector rope has a special covering destined
to take the wear. Each
Has. 444 and 445. strand has a wire
wound round it spir-
ally, which protects it
from rublnng, and
therefore a more flex-
ible wire can be used
than would bo advis-
able with an unpro-
tected rope. Whilst an
ordinaiy rope is weak-
ened by the wear of
its wires, the strength
of the protected rope
does not suffer frooL
the gradual thinning
of the covering.
Messrs. lAtch and
Batchelor have lately
introduced a"flattened
strand "rope (Figs. 448,
449, and 450). The
object of the new
method of construction
is to obtain an out«r
surface more nearly
cylindrical than that
of the ordinary rope
(Fig. 443a)- The
strands are oval in
I Bection, and this form
I is produced by " lay-
ing " ordinary wires
round a flat wire or a
combination of wires. It is evident from the figures that the
bearing surface of the rope is thus increased, or, in other words,
that the liability of any individual wire to wear ie lessened. It
is osaerted by the inventors that their rope has 150 per cent,
greater wearing surface than Lang's or ordinary ropes.
In designing the " locked coil wire rope," now made by Ateesrs.
Qeorge Elliot & Co., the inventors departed entirely from the
old traditions of manufacture. They considered, and very properly.
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JIOISTING OR WINDING. 401
th&t vhen one is dealing with & m&terial like steel-wire, whidi
oaa be obteiaed of very great length, it is quite unDeceseaiy to
cop7 the methods suitable for the short fibres of hemp,
^ese ropes are made of wires of different sectioDS ; some of the
wires are V-shaped, others more like the letter S, and the adjacent
wires fit into one another like a set of spoons, the concave part
of one wire receiving the convex part of the next. The rope is
not composed of a series of strands, but of a series of concentric
rings of shaped wires, and the separate wires form long spirals.
By consulting Fig. 451, which represents one vaiiety, it is
evident that nearly the whole of the section of the rope is made
up of useful material. There are scarcely any spaces such as
exist between the wires and the
strands of an ordinary rope, and Fio 451
consequently for any given section
the locked coil variety of rope is
stronger than a stmnd rope.
It is very flexible and has a smooth
uniform surface, which mokes it
look at a little distance like a solid
bar of iron. No one ^vire of the outer ring is more ezpoeed to
wear than the other ; consequently there is not the danger of
havlDg broken wires, arising from the top of the crown being
rubbed off by continued use (Fig. 445). Another advantage is
the absence of any tendency to turn, iniereas the ordinary rope
with the spiral strands twists somewhat when passing over a
pulley. In sinking a shaft with such a rope, the kibble spins
round during its descent and ascent, involving a risk of accident,
which is best avoided. However, strand ropes that will not twist
4U*e supplied by some makers.
The disadvantage of the locked coU rope is that it cannot be
spliced, but sockets can be used for connecting one length to
another.
Intermediate in character between the ordinary rope and the
locked coU rope is the variety known as I^dler's patent " Sector
wire rope." Each strand is cylindrical, and is composed of several
wires in the foirm of sectors of a circle, and the atiands are laid
together to make the rope. Fathom for fathom, it is a little
heavier than Lang's rope, but it is said to give a great deal of
■wear.
Chain B. — Chains were largely used in ore-mining at one
time. They have the advantage that they will coil round a
small drum, and the further advantage that they will stand much
rough usage, such as fell to their lot formerly in some |of the
crocked shafts in Cornwall, But there ' is the overwhelming dis-
advantage that a chain is no stronger than its weakest link ;
and now that wire ropes have come into use in mines, winding
with the chain is practically a thing of the past.
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401
ORE AND STONE-MINING.
Attooltmetita. — It is important to study the modes of oonnect-
ing the rope to the receptacle by which the miDmil
is drawn up. In sinloiig by hand in Oomwall, Fio. 452.
the hemp rope is attached to the bucket by a knot
known as the " gooseneck," which is said never to
slip, and which is easily and quickly made ; but
where the bucket in emptied without being de-
tached, this latter point is of little importance.
In Wales and the lale of Man a spring hook
(darie) is preferred, euch as shown in Fig. 453,
the rope being put through an eye and made secure
by a large knot. This method is convenient when
it is neceesaty to detach the bucket, and move it
away from the shaft before it is emptied. A third
device is a spiral hook which will not allow the backet to fitU
off in the operaticms
Fio. 4S3. Fio. 455- P^- 4S*- of raising and lowei^
ing, whereas it can
be readily taken off
by the workman.
With a wire rope
it is necessary to form
a loop of some kind,
which can be attached
to the load by a D-
shaped link with a
screw pin. There are
several metinB of ef-
fecting this purpose.
The ropes sent from
the nu^eis are often
supplied with an eye
splioed in {Fig. 453%
that ia to say, the end
of the rope is turned
round an eye and
then spliced back so
as to hold it firm. As
there is not always
a competent splicer
at mines, methods of
attachment have to
be employed which
are within the capa-
^^- 454- city of an ordinary
smith. Thus the end of the rope may be bent back over an eye
* Copied, b J penniuioo, from UeMrt. Oeoige Ciadook Ic Co.'s flgiuea.
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HOISTING OR WINDING.
403
and held in portion by three clamps (ilge. 454 and 455),* or a
socket may be riveted on (Fig. 456).*
^8^- 457) 45S and 459 represent a socket made by Messrs.
George Elliot & Co. for the locked coil rope and for ordinary round
wire ropes. A, locked coil wire rope; B, socket; C, hollow conicat
plug; D, wire bound or "served" round the rope; E, ends of
the wires of the rope turned back over the cone ; F,*wire bound
round them. Aftei- the end of the rope has been prepared in
Fio. 460. Fia.461.
Fia, 4S7, Fio. 458. Fio. 459,
this way and drawn into the socket, the rings G Q G are driven
down, and the fastening is complete.
Figs. 460 and 461 explain the "capping," which has been
adopted at some collieries near Bristol, since the failure of a
riveted socket. A A, clamps for holding the rope, each with
four bolts; B, cast-iron pute with a groove all round it in
which the rope lies ; C, a large shackle attached to the iron plate
by a pin E.
A description of the method of splicing ropes will be found
* Copied, by permiadon, from Messrs, Oeotse Craddock ti Oo.'a flgtueB.
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404 ORE AND STONE-MINING.
in the catalogues of some of the well-known rope-makera, bnd
need not be repeated here.
Splicing is not always adopted for joining two parts of a wire
rope ; sometimes a socket is attached to each end, and the two
sockets are then connected bj a D-link with a screw pin. It
should be remarked that it is often at or near the Bo<^»t that
the rope wears, and consequently it is advisable to remove the
sockets at regular intervals, cut off a piece of the rope, and
replace the socket where the rope is good and sound.
I have hitherto been speaking of winding ropes of uniform
section, but taperingropes have advantages. Let us take the case
of a wire rope which is hanging down a deep pit. The part of the
rope at the bottom of the shaft has simply to support the cage
or bucket and the load contained therein, whilst the part at the
top must be strong enough to support not only the weight of the
receptacle and its load, but also the weight of the rope below it.
In other words, greater strength is required at one end of the
rope than at the other, and on this account t&pering ropes are
sometimes employed.
The advantage of employing such ropes is especially felt in
the case of very deep shafts, such as those of the famous lead
and silver mines of Pribram already alluded to. Three of the
principal shafts have the following depths :
EaiserFnuu Josef shaft .
tooo metiea or 32S1 feet
Adalbertshaft .
1070 „ 3510 „
Maria
. .110 „ 3642 ,.
FlO. 46*.
The taper is produced by using suocessirely wires of smaller
iection, and not by reducing their number.
3. BECBFTAOIiES. — There are three kinds of receptacles
In which the load is raised in the shaft : (a) Buckets {kiibUa),
baskets or bags which are swinging loose in the
shaft ; (6) buckets or boxes {sJiipt, OomwaJl)
working between guides ; (e) cages carrying one
or more waggons.
(a) The buok«ta are made of wood, sheet
iron, or sheet steel.
Wooden kibbles aro made of staves in the
same way as a barrel, and are suitably strength-
ened with bands of iron in order to resist the
wear. A petroleum barrol cnt down at one end
may be eamly converted into a kibble.
Various forms are seen — viz., round, elliptical,
or square, and the sides are straight, or bulging
in the middle. Fig. 463 represents a conunoQ
form of sheet-iron kibble, made of hammered
plates riveted together and closed at the bottom by a circular
plate provided with a ring. At the top is the so-called bow,
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HOISrnfG OK WINDING. 405
either a bar of round iroD yiith a hook at each end and bent
BO aa to form a loop in the middle, or else made thicker and
provided with a hole, to which the rope or chain is attached.
In perpendicular shafts, a lining of planks is often put in
around the winding compartment, so that the kibble ma; glide
up and down smoothly, without risk of catching against the
sides.
In inclined shafts the "footwall" side is lined with boards
(bedrplania) resting upon cross sleepers. Hard wood, such as oak
or beech, will naturally last longer, and require fewer repairs
than desl. In the Hartz, poles fixed lengthwise take t^e place
of boards, which are customary in this country.
Other receptacles used in winding are bRskets, whence comes
the name corf{Korb, German), bags made of hides nsed in Mexico,
smaU wooden platforms suspended by chains from the f out- comers,
and, lastly, nets, which are employed in Boumania.
A word must be said about the actual loading and emptying of
the Hbble ; sometimes, as already mentioned, the kibble is filled
at the working-place or from a shoot (pass, Cornwall), and is then
canveyod on a trolley to the shaft, where it is hooked on to the
rope and drawn up. More frequently the filler, standing in an
enlarged part of the level {plat) where it joins the shaft, loads the
kibble with a shovel ; in order to save time, two kibbles are
often provided, one being filled while the other is making the
i*oumey to and from the surface. In this case it is necessary to
lave some kind of clevU, which will enable the kibble to be readily
detached from the winding rope and quickly and securely fastened
on again.
On the srrival of the kibble at the surface, the lander seiros
an eye or ring at the bottom (Fig 463) by a pair of tongs sus'
pended to a chain, and then gives the signal for the rope to be
lowered slightly. The kibble turns over because it is suspended
from the bottom, and its contents are shot out into a tram-waggon
placed ready to receive them. During the operation of diachai^-
ing the kibble, the moutii of the shaft should be covered by a
hinged door, so as to prevent stones from falling down and
injuring the filler in the plat.
The inconveniences of this method of winding are considemble,
especially in inclined and crooked shafts. Bapid hoisting is ont
of the question. Power is wasted in overcoming friction, and
there is great wear and tear of the bed-planks and casing bcMtrds ;
and, unless constant attention is paid to repairs, boles sre worn in
which the kibble catches, causing the rope to break. The foil of a
kibble and its contents not only does much damage to the shaft,
but is also a source of danger to the men. In some old shafts the
friction must have been enormous, for deep grooves have been
worn in hard rock by the constant rubbing of the chain.
The aerial incline, known in Scotland aa the " Blondin," is a
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4o6 ORB AND STONE-MINING.
cotiTcaiieiit method of raising stone from open qnanieB, when it
is neoesBaiy from time to time to alter the point at which load-
ing takes place.
A B {Big. 463 *) ifl a strong upright post, held firmly in posi-
tioo by guy ropes, of which only one, C A, is shown. A D is a
stout wire lupe, fixed to the top of the post, and anchored at D
on the opposite side of the quarry. It ooDstitutes an atrial rail
for two groored pulleys contained in the travelling cradle E.
The rope F, attached to the cradle, passes over the large ptdley
G, and thence to a horizontal winding-drum, not shown in the
figure. The engine-house is at the very edge of the quany, and
IB so placed that the engine-man can look down to the bottom.
The cradle E will run down from A to D by its own weight, and
can be drawn up by winding the rope F upon its drum. A loop
attached to E suppaits the large pulley H, and the hoisting rope
I. This rope passes under the pulley E, over the pulley H, over
a pulley immediately by the side of O, and thence to a drum
precisely like that of F, and running upon the same shaft. L is
a rectangular box, like the body of a waggon, which is loaded
with stone at the bottom of the quarry, and hooked on to the
four chains hanging from E ; it is then drawn up and landed on
to the truck U. I will suppose that the load has been hooked at
the point N in the bottom <n the quarry, vertically below L in its
present position. The drum of I is thrown into gear by a clutch
and the rope wound up. K. is gradually raised, and when it ap-
mxwchesH, the drum belongingtoFis thrown into gear; the ropes
f and I are now wound up at the same speed, until E is drawn
close up to A, with its load hanging directly over M. Winding
is stopped, bmkee are put on, and the drum of I is disengaged by
its clutch. By slackening the brake of I, while that of F is kept
tight, the load can be lowered on to M, which is trammed away
as required. An empty box is hooked on, E is wound up a little,
till it approaches U, and then, throwing the drum of I out of
gear, the engine-man lets both ropes run out under the control of
their brakes. When E has reached i(« proper position, it is
stopped by tightening the brake of the F drum ; E then descends
vertically till L has reached the bottom of the quarry.
It is evident that by properly arresting the descent of E, the box
can be lowered so as to pick up a load at any point along the line
0 P, which is vertically below A D. If after a time it becomes
more convenient to load elsewhere, the anchorage at D is shifted
accordingly.
At slate quarries in Korth Wales and Cornwall, the rope F is
not used, and E is stopped by a clamp fastened at any desired
point of the rope A D. The arrangement shown in Fig. 463
introduced many years ago by Mr. Fyfe at granite quarries near
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HOISTING OR WINDING.
Fia. 463.
A
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4o8 ORE AND STONE-MINIBG.
Aberbeen, ia better, for it does away with the necessity of
Bending a man down the rope to adjust the clamp. A Blightly
different plan is in nse at Easdale ^ate quarry in Argyllshire.
The travelling cradle carries the asual hauling rope I, but in place
ot F there is attached to it an endless rope, which stretches
across the quarry, and pasaee over suitable puUeys. So l<mg as
the endless rope is free to move, the cradle will nm from A to
D, but when the banksman stops its travel by a screw clamp,
the load ascends or descends vertically. If the slope of the
Carryinf; rope fixed across the quarry is too small to allow the
cradle E to run of itself, an endless rope, worked by a drum, ia
used for hauling it backwards or forwards as required.
(b) O-ulded Buoketa or Boxes. — When winding in shafts it is
best to employ guides, in order to keep the receptacle in one proper
course,and prevent it from touching the aides. Theguidesinaybe
chains, wire ropes, bars of wood or round iron, or, lastly, iron or
steel rails.
Chains are rarely met with ; the commonest method of guiding in
perpendicular shafts is to hang two stout wire ropes from the top
to the bottom of the pit, and to provide the winding receptacle with
eyes which pass over them. Thoy are kept taut hy weights or screws.
Wire-rope guides may be used even in the case of a kibble ; a
croBS-bar with two eyes is attached near the end of the winding
rope ; though the kibble remains loose, it is so close to the cross-
bar that it can swing but little. By fitting wire-rope guides of this
kind to perpendicular shafts originally worked with the ordinary
loose kibble, winding can be carried on
Fig. 464. ^itii greater speed and safety, whilst the
cost of making the alteration is com-
paratively small. There is the further
advantage that the shaft when provided
with guides becomes available for raising
and lowering the men.
Some years ago Mr. William Galloway*
introduced an ingenious method of apply-
ing these wire-rope guides to a shaft in
the course of sinking. He provides two
wire-rope guides coiled upon two drums
which are worked by a Ht«ain crane,
either separately or together. The guide
ropes (a a, Fig. 464) pass over two pulleys
at the top of the shaft, parallel to the
winding pulley, and are attached to a
tilatform, which serves aa a walUng stage, and is raised and
owered as required. A hole in the middle affords a passage
for the bucket {kiible, bowk, hoppet).
• "StnkioK AppliancBs at Llaabradach," ZVani. SwrfA WaUt Jvil. of
Eng., vol. xtL, 18S8, p. 113.
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HOISTING OK WINDING. 409
As the shaft is deepened, the guide ropes are paid oat from
time to time, and in this manner it is only at the very hottom
that the bucket is swinging looBe. The guiding apparatus consists
of a cross-bar having a round hole in the centre e, through which
the winding rope passes. It has two legs with holea, h b, at top
and bottooL which receive the guides. This rider descends as
the bucket is lowered, but when the tegs meet with the walling
stage their motion is arrested ; the kibble, however, can proceed
further because the winding rope passes down through the central
hole e.
After passing below the stage the kibble is ungiiided, but the
distance it has to travel is rarelf more than 15 or 20 yards. Before
starting on its upward journey, the kibble
is brought properly into line with the rope ''^^' *^S-
and steadied, anil on arriving at the stage,
an india-rubber buffer, carried by an iron
plate at the bottom of the rope, lifts up the
rider ; the remainder of the ascent is per-
formed without fear of the kibble swinging
or catching.
Mr. G^oway's latest walling stage has
two floors, 10 feet 6 inches apart ; the lower
one is a drcalar platform of timber fixed
to a frame of angle-iron d^ r^ (Figs. 465 and
466), and made to fit the inside of the shaft
as closely as possible.
The part k is hinged, and can be raised by
means of the chain, when passing the cross-
beams {buntOM) which support a ventilating
pipe. The upper floor of the stage is similar
to the lower ooe, except that it is somewhat
smaller in diameter, and is not made to
cover the hinged segment below. The two pj^ -gg
floors are held apart by four comer pieces
of angle-iron, to which are attached four plates of sheet iron,
forming together a frustrum of a pyramid, 5 feet 6 inches square
at the top, and 6 feet 6 inches square at the bottom. The object
of these plates is to prevent men who are standing upon the
lower stage from falling into the central opening, and at the same
time the upper floor constitutes a protecting roof over their
Men can climb from the lower to the upper platform by means
of the ladder m which passes through a small man-hole in the
iron covering plates.
The two guide ropes which carry the stage are shown by
letters n n'.
This double stage is decidedly Eafer than the single platform
originally employed by Mr. GaUoway.
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4IO ORE AND STONE-MININQ.
Althoiigli prinuLrilf dedgned for sinking coal-pite, and moct
frequently applied tor this purpose, this method of guiding was used
with marked success in sinking a shaft at New Minera lead and
zinc mine near Wrexham ; it was found that the great advantage
of being able to wind with safety at a higher speed, fully repaid
the expense of putting in the guides.
In the Northwich mines, rock-salt is brought up in wooden
buckets guided much in the same way, except that round iron
bare are employed instead of ropes. Each length of rod has a
socket at one end and a projecting pin at the other ; the pin of
one rod fits into the socket of the next and is fastened by n
key driven through a slot. These guides are chosen in the special
case of salt because they tmffer less from rusting than those made
of wire nmes, owing to the absence of interstices in which saline
water would collect and corrode the iron.
We next come to the box of rectangular or circular section
(attp), made of sheet iron or sheet steel. It usually has a sloping
bottom, and is provided with a hinged door for discharging its
contenia ; in some instances it is emptied by being turned over
automatically on reaching the top of the shaft. The skip may be
used in perpendicular, inclined, or crooked shafts. The guides ot
conductors are most commonly redaugnlar bars of wood, bolted Ut
the end-pieces of the shaft and to the " dividings " in the manner
shown by Fig. 257.
If the shaft is perpendicular the skip may be guided by two
U-shaped shoes of iron, which clasp the three sides of the con-
ductor. If it is inclined the skip runs upon four wheels, as shown
by Fig. 467. In an inclined shaft the conductors sometimes have
rails, upon which the wheels of the skip run, in others the timber
is not prat«cted in any way. Some of the skips in Cornwall are
made to hold as much as a ton and a half of tin-bearing rock.
When winding is going on from any particular lerel, a stop,
such as a strong bar of iron, is put across the shaft to nrrest the
skip ; the miner, standing in the plai, shorelB the mineral into it,
and gives the signal to have it drawn up as soon as it is filled.
A better plan is to adopt the arrangement explained in Fig. 46 7 ,
which will easily be understood. B is a strong plate working on
a pivot which is put down to stop the skip ; 0 is a pivoted hood
turned over tho mouth of the skip so as to prevent stones from
falling into the shaft, and when this is in its place the workman
raises the door of a large bin or hopper, and allows part of its
contents to run out. The hopper has been filled by tipping
waggons from the line of nuls in tbe level above.
On reaching the suifooe a hinged sloping door is turned over
the shaft, and the skip is lowered a little until it reste upon it ; tbe
workman (lander) then knocks up the bolt rtrtaining the door of
the skip, and the contents fall out into tbe tram-waggon placed
to receive them. The lander replaces the bolt, the skip is raised
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HOISTING OR WINDING. 411
slightly, the door pulled back, and the skip lowered once more
into the shaft.
The skip is Bometimes tilted completely over instead 4^ being
emptied through a. hinged door ; thia arrangement is in use in
fiome German mines, where the skip is made of wood and is guided
on each aide by two pinti or rollere running between two con-
Fio, 467.
ductora. On reaching the surface, the two lower pins ai-e sup-
ported and act as pivots, while the upper ones pass through
openings in the front guides ; the skip turns upon the lower pins,
is tipped over, and so emptied.
Some veiy rapid work is done at Ce Beets mine* with a self-
discharging skip, which shows that this method of hcasting must
not be despised, even by those who are acciistomed to the wind-
ing of large quantities of coal from well equipped pits.
I, Limited, for the
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4ia ORE AND STONE-MINING.
The skip (Figs. 468 and 469) rnns upon fonr flanged wheels, and
the two upper or front wheels are half the width or tread of the
two back or lower ones. The winding rope is attached to two
chains, which are fixed to the croes-bar of a loop or atimip which
can turn upon pins fixed to the sides. The skip runs upon steel
Fio. 468.
rails (46J lbs. to the yard) laid apon what may be called con-
ductors or longitudinal sleepers. At the bottom of the shaft
there is an iron shoot, without any door, leading to the skip.
During the descent of the skip, four end-tipping waggons are
brought into position round the shoot, the catches of the flapnloors
are loosened, and the doors held closed by two labourers. As soon
as it is seen to pass, the trucks are tipped, and the signal is given
Fio, 469.
to wind up. The skips are filled so quickly at the bottom, that
the man at the top sometimes receives this signal before he has
completely stopped his engine.
When the skip B (Fig. 442), ascending the incline shaft A,
reaches the point C, its rear wheels ar« caught up by a special
broad road D, the gauge of which is wide enough to let the front
wheels pass through. Whilst the front wheels are travelling on
the rails E, the rear wheels continue to mount, and consequently
the skip turns over and discharges its contents into the bin F.
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HOISTING OR "WINDING. 413
H is a TBggon waiting to be filled, and G a counterpoise to the
discharge door.
Od lowering the rope, the skip falls back into its original position
and descends the shaft. The inclination of the shaft is 56° 20'
from the horizontal. The skip-ways are 5 feet wide and 4^ feet
high, and the gauge of the railway ia 3 feet 1 1 inches. There are
two tracks, which converge at the bottom into one, so that both
skips can be filled from the same shoot. A skip holds 64 cabic
feet, or 4 loads, weighing in all 2 tons 17 cwt., or 2903 kilos.
The host single day's work, in two shifts of 10 to loj hours
each, was 6222 loads, or 4444 statute tons. The depth of the
Fig. 4^ Fia. 471.
shaft is 840 feet alone the incline, or 700 vertical; the speed in
the shaft is S40 feet in 30 seconds, and the time occupied in
tipping and reversing about 6 seconds. This rate of working
has been carried on for an hoar at a time, 5 skips being discharged
every three minutes — that is to say, 285 statute tons per hour.
Fig. 470 shows the details of double-ljpped mouth of the shoot
at the bottom of the great bin (F, Fig. 442), which receives the
bine ground brought up from underground. The door A. is con-
troll^ by the cam worked by the lever B, and the door 0 is upon
the same axis as the lever D. The discharge is thus easily
regulated, and waggons can be filled with great rapidity.
The arrangement for inclines shown in Figs. 471 and 472
differs slightly from that adopted at Se Beers. A waggon A,
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414 ORE AND STONK-MININa
running upon four wb«eb B, is drawn up hy the bow F, sod the
rope J, The boT is attached to the axlee of the hind wheeb.
and in front it carries the door I of the waggon. K repr»-
eente the railway at the top of the incline, and P an additional
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HOISTING OR WINDING.
415
outer line of tails at a steeper angle. When the waggon in
its upward course reaches the point L, the ikUb P pick up the
small outer wheels C on the rear axle. These travel up at the
steeper angle whilst the front wheels follow the rails K. Conse-
quently, the waggon is tilted, and, as the front end or door is
attached to the bow, the contents are shot oat. The stud G keeps
the waggon in poeitioQ if it is
drawn up too far. On lowering Fia. 474.
the rope, the waggon rights
itself and descends properly.
Automatic tipping, or dump-
ing, is also poesiUe in per-
pendicolar shafts. The "Book"
shaft at De Beers ie zo feet by
6 feet, divided into four com-
parbnents which are each 4
feet 4 inches by 6 feet within
the timber : one for the pumps
and ladder-way, another for a
cage, and two for the skips.
Figs. 441,473 and 474* repre-
sent the anangements adopted.
A is the skip, a box of rect-
angular section, 5 feet by 3
feet at the top and 6 feet
deep; B, frame which clasps
the wooden guide on three
sides ; C, hinge by which the
skip is attached to the frame ;
D, hooked bar which catches
upon the pia £ ; P, guide which
presses the little roller D^ and
so unhooks the catch ; G, roller _
which travels along the guide- ""
rails H for causing the tipping ;
I, nose npon the ^p, which is
temporarily caught upon the
roller J during the tipping ; K.,
inclined guide for the roller
Q ; L, croflspiece attached firmly to the side-fnunes B, with a
bole M, through which slides the stnntg square bar N; 0,
toothed segmanba forming the safety catches ; F, plate attached
by chains to the axles of the catches ; Q, Onnerod's detaching
link ; R, shackle which is released ; S, rope-socket ; T, wire-rope ;
V (Figs. 441 and 475), bell-mouthed cylinder for causing the
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4i6 ORE AND STONE-MINING.
detacliiiig link to come into action; Y, chain-puUe; of safety
catch; W, strong spring, like a huge watdh-spring.
After this explanation of the porta, the manner in which the
tipping or dumping is performed will be easily understood. As
long as the hook D is horizontal, the skip is prevented from
falling forwards, but on arriving &t the top of the shaft, its
roller D* is drawn up against the guide "F and the catch is released.
By this time the roller G has reached the guide-rails H, and
whilst the frame B follows a vertical path upwards, the box
itself, held back by G, turns upon the hinge C until it assumes
the position shown by the dotted lines, with the nose I resting
upon the roller J. As the frame aecends still further, the roller
Q is drawn up along the inclined guide K, the bottom of the
box is tilted np, and its contents are discharged into the bin
or hopper. On lowering the rope the frame descends, the skip
drops back into its original norma] position and is clamped
automatically by the bar D.
Whilst the plate P is held up against the cross-bar L, the
chains of the safety catches 0 are drawn tight, and the te^h are
held clear of the wooden guides in the position shown. The
moment the rope breaks, the chains become slack, the springs
are then free to uncoU slightly and they force
Fio. 475. ^B teeth into the wooden guides.
If, instead of a breakage of the rope, there
is an overwind, the detaching link Q is drawn
into the bell-mouthed cylinder U (Fig. 475)*
the lower part of the link is squeesed, as it is
too wide to pass through, and b thereby
caused to throw out projecting shouldeia
which rest upon the top of U and hold up
the skip. By the same action the shackle
& is set free and goes with the rope over
the pulley.
A self -discharging skip, suitable for vertical,
inclined, or crooked shafts, Is that of Messrs Kitto, I^ul and
Nancarrow, used at Frongoch mine in Cardiganshira.* (Figs. 476
to 480).
The skip is the usual box A, made of sheet iron ca* sheet steel,
with four wheoU B B, running on the vertical wooden conductors,
H H, and prevented from leaving them by the back guide D
(Figs. 477 and 479) at or near the bottom.
The bow or loop E, instead of being attached to the top of the
skip, reaches down, and takes hold of the axles of the bottom
wheels; in its usual position (Fig. 478) it reets against the axlaa of
the upper wheels, and holds the skip upright.
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HOISTING OK WINDING. 417
At the Burfaoo, each of the two ordin&ry conduotors bends
round and terminates in a horuontal piece, as shoirn in Fig. 480,
whilst a front guide H' is added on each aide.
When the skip comes up, these front guides press upon the
top wheels, and turn them on to the fiat ends of the ordinary
oonductors. Deep grooves cut in the conductors at I enable the
back guide D to pass through, and as the rope continues to be drawn
up the bottom end of the skip is raised and its contents are tipped or
" dumped" into a large bin or paa», from which the ore can be
drawn away at pleasure. If the engine-man does not stop quite
soon enough, the skip is simply drawn up a little way, resting
upon the front guide, and the atop or stud F prevents it from
assuming a wrong position.
PiQ. 476. Pig. 478.
F10.480.
F10.477. F10.479-
As soon as the engine-man begins to lower, the top wheels
fall upon the flat ends of the conductors, and, turning upon them,
the bEtil end of the skip drops, the back guide passes through
the slot I, and the skip, resuming its upright position, descends
the shaft.
The great advantage of this and other self-tipping arrange-
ments is the saving of time and labour. The time o«xupied in
lowering an ordinary skip on to the shaft-door, in knocking up a
bolt so as to discharge its contents, in closing it again, and in
raising the skip so that the shaft-door may be thrown back, is
all saved, and the services of the Umder are dispensed with.
(c) Cage. — The system of winding adopted almost universally
at collieries is that of using cages ; this method is likewise very
general in mining seams of ore, and is not u
of veins and masses.
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4i8
ORE AND STONE-MINING.
The cage, as ite name imfdies, is a more or less open receptacle,
which receives the waggon uaed for underground transport, and
conveys it to the surface.
f^gs. 481 and 482 represent the light and simple cage used in
the mines on the Gomstock lode : * it is a mere timb^ platform
5 feet by 4 feet, resting on iron bars p and supported by iron rods
on each side. It is provided with a sheet-iron bonnet to protect
the men inside from anything falling down the shaft, and also
with safety catches, whi<^ oome into play if the rope breaks.
Fio,48i.
The hand levers i i at the ends of the cage, laiae up blocks
which keep the tram-waggon in its place during the ascent or
descent ; g g are the guides for the ends of the cross'bar b ; e, the bar
working the teeth 1 1 by levers; f ahoe or ear embracing the guide-
rod, or conductor, in the shaft ; r, the lifting bar ; «, a strong
spring which comes into opeiation if the rope breaks.
This kind of cage looks somewhat bare to European eyes, and
it is usual, on this side of the Atlantic, to make the sides lees open
than shown in Fig. 4S3.
The dimensions of the cage are limited by the else of the shaft ;
but where it is desired to raise a larger quantity of mineral than
. V. i
Gtci. MiqiL of yotA
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HOISTING OR WINDING. 419
'Can be contained in one waggon, or in two placed aide b^ side, the
.carrying capacity may be increaHed by constructing the cage with
two or more platforms, technically called daeka.
Afi a rule, the full waggon is drawn out of the cage at the top
-of the shaft, and is trammed to some convenient place where it is
"tipped ; of late years the ingenuity of American inventorB has led
them to introduce methods of tipping the waggon automatically
on reaching the surface, without its leaving the cage, in order to
save time in winding, Ruasell and Parson's automatic dump-
ing cage, said to be doing good wcvk in the United States, has
its platform movable upon an axle underneath, which allows it to
be tilted on one side or the other. The cage has the usual shoes at
the top and bottom, which cover ^\ inches of the wooden guides
or conductors; the tilting platform has its own two separate
shoes, which clasp only 3^ inches of the guides. Whilst the cage
is in the shaft, the platform ia held in a horizontal position by its
shoes running upon the guides. At the sorface the wooden con-
'ductors are cut away for a depth of 2^ inches, so that, although
the cage itself is guided, the small shoes are free to move side-
ways and permit the tilting, when the platform touches a properly
arranged stop. The flap-door of the waggon is released automati-
'Cally at the same time, and the mineral is shot out into a large
bin at the pit-top.
4. OTHEB AFFIiIAD'CES — Eeps. — On arriving at the
.-surface the CB^e is usually lifted a little higher than the landing
platform, and supports of some kind ijeepi) are brought under-
neath it, so as to hold it up while the full waggon is drawn off
and an empty mggon pushed on. The cage is then slightly
raised, the supports (kepi) are drawn back by a lever, and the
descent begins.
Several methods of simplifying the work have been devised,
-and among them is that of Messrs. Haniel and Lueg,* which has
been found to act satisfactorily at the well-known Mansfeld
-copper minee.
^e kep a, which is made of steel (Figs. 483 to 485), has an in-
-clined face h, and is provided with two slots, one horizontal and the
other A inclined. The former acts as a guide to the block «,
which is loose upon the axle /; f ia supported by the bearing g.
The pin i, surrounded by a steel roller k, can fdide in the slot
■d ; it connects the two levers k, one on each side of the kep
a, which are keyed to the axley. These are kept in a horizont^
position by a lever in provided with a spring catch. The steel
shoes / /, attached to the bottom of the frame of the cage, will,
if desired, rest upon the inclined faces 6 6 of the keps. As long
as the lever m is held in the position shown in Fig. 483, the keps
cannot open under the pressure of the load, because the pin i
prevents any motion in a horizontal direction.
* The explanation and figures aie boirowed from tbeii description.
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420 OBE AND STONE-MINING.
When the lever m is being drawn badE, aa shown by Fig. 484,
the pin t with its roller h is forced up the elot and the kepe slide
back on tfae bed-plate of the bearing g, until the cage b&s room
enough to pa«s ; when it has gone down, the kepe are returned to
their original position
no, 483.
lever m torwarda.
The ascending cage
opens the kepe by
itself, for the shoes
1 1 turn them upwards
(Fig. 485)1 the lower
part of the slot d
being concentric to
the spindle /. As
soon as the cage has
passed, they fall back
into their normal posi-
tion (Fig. 483), and
the cage is lowered so
aa to rest upon them.
The advantage
claimed for keps of
this kind are: Eco-
nomy of steam and
saving of time, besides
the increased duration
of the rope, which no
longer has to under-
go the strain of start-
ing the cage upwards
before it begins its
downward journey.
Signals. — It is ne-
cessary to have some
means
cation between the various on-setting places and the top of the
shaft, so that the man at the bottom (tm-aetUr, Koo/cer-on)
may be able to inform the man at the top {banJcaman, lander, or
en^jis-man), when he is ready for the cage, skip, or kibble to
be drawn up.
In shallow workings shouting is sufficient ; when the pit becomes
deeper a speaking-tube is sometimes put in, but the commonest
method of signalling is by a cord made of seven galvanised wires,
and vaiying in diameter from ^ to | inch. The object of the
iinc coating on the wire is of course to prevent or delay
rusting, which would otherwise go on rapidly in the damp
atmosphere of many shafts.
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HOISTING OR WINDING. 421
The cord ie carried round curves and comers by means of
cranks similar to those used for house-bellB, only larger and
stronger, and when it is pulled by a lever at the bottom, it
moves & hammer which stnkeB a bell at the surface. Instead of a
bell, a loose plate of iron is sometimes used, which makes a very
audible signal ; the number of strokes indicates what is required.
The usual code is as foltows :
I Htroke means " Stop."
3 Btrokes mesn " Wind op."
Yarious signals can be arranged to indicate when men are to be
drawn up in place of the ordinary load of mineral ; and sometimes
a visible signal is combined withanaudibleone, ahanduponadial
recording rtie number of times the bell baa been sounded. When
persons are raised and lowered, there must also be means of
signalling from the surface to the on-setting places ; the object
is to assure the men at the bottom that their signal has been
correctly received and understood.
Electricity can also be called to the aid of the miner, and electric
bells are common. Telephones * of various descriptions are some-
times used, but for the ordinary purposes of winding, the simple
signal given by a bell is quite sufficient.
In addition to the signal for starting and stopping, there is
an indicator which shows the engine-man the exact position of
the load in the shaft.
The indicator may be a dial with a hand, worked by gearing
connected with the crank-sbaft of the winding-engine; the
various stopping places are denoted in the same way as the hours
on the face of a clock, the gearing being arranged so that the
band does not travel more than the entire circumference during
the longest journey of the load.
Anol^er form of indicator is an upright standard, 6 or 8 feet in
height, with a slot, in which a pointer moves up and down. It is
worked by a cord, or a steel band connected to the crank-shaft.
The standard has horizontal lines, numbered according to the
depths of the different stopping-places ; the gearing is contrived
so that when the finger points to'oneof these lines, the cage is at
the corresponding stopping-ptace.
The arrival of the load near the surface may be brought to
the engine-man's notice in several ways ; by a mark on the rope,
by the pointer on the indicator, and by some audible sigiml,
worked automatically by the winding-engine. A. travelling
hammer may be carried along by a screw, connected by gearing
g the telei^one was used for tTsnamittiog Bpe«ch from
: 1 — : ;_ September 1877, when Mr. Arthur
a at West Wheal Eliia, In Con-
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42X
ORE AIJD STONE-MINING.
with the crank-shaft, and eventually brought up againBt a bell ;
it works in the same manner ae the device upon typewriters
which warns the operator that he is coming to the end of a line.
Instead of striking a bell, the traveUer may open a cock and start
a steam whistle.
5. SAFETY APPLIAKCES — Orerwtodii^.— In rapid
winding with large drums, a slight inadvertence on the part
of the engine-man may cause the load to be drawn up against
the pulley, and this is what is commonly known as ot>er-viinding.
In the case of a drum 18 feet in diameter, a single revolution
raises the rope 56^ feet; therefore, if even half a revolution la
allowed beyond the proper number, an accident will ensue, unless
the pulley frame gives a margin of nearly 30 feet.
There are various oontrivanca for preventing disasters of this
Fio. 4S7.
kind ; one method consists in interposing between the rope and
the cage a special appliance, called a detaching hook, which will
sever the connection between them, allow the former to be
wound up, and at the same time hold up the latter safely without
damage to the load or persons inside.
Some well-known detaching hooka are those of King and
Humble, Walker, and Ormerod (Fig. 475).
King and Humble's consists of an outer framework of two
cheeka or sides, containing two inner platee which can move about a
central bolt h (Fig. 486), Each plate has a wing a, projecting
beyond the framework. When in use the two plates are pre-
vented from coming apart by a small pin or rivet, c.
If the cage attached to e is wound beyond a certain height,
the detaching hook is drawn into a round hole in a. strong
iron plate (£^g. 4S7), and when the projecting wings, a a,
strike against this plate, they are forced to move inwards, tha
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HOISTING OR WINDING. 423
rivet is cut, the shackle d at the end of the rope ia set free, and
two catchesy^ are thrown out ; these drop upon the plate and
hold the cage firmly Buspended,
Walker's detaching and sugpeudiii^ hocA is like a pair of
tongs, which hold the shackle at the end of the rope ; the legs
of the tonge are bent out, and if they are brought together the
tongs open.
Fia.489.
Fia.488.
In Figs. 488, 489 and 490, L is the end of the winding rope,
and A the shackle attached to it by the pin P. D D are the
two jaws of the tongs, and F F are projecting hooka, £ is the
centre pin about wluch the jaws can move, and H an annular
clamp which prevents the jaws from opening, as long as it is
kept up by the two supporting pins I I. The cage or akip is
hung on to the link B, and the weight of the load acting upon
the two lega of the tongs tends to bring them together and open
the jaws D D.
When winding is going on properly, the jaws are kept together
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4^4 0KB AND STONE-MINING.
by the clamp, and the load remains firmly attached to the rope ;
but if it 18 raiaed too high the detaching hook enters the strong
ring G, through which it can pasa freely until the flanges K K of
the dajnp H strike against it. The pins 1 1 are sheared off and
the clamp dnm ; but as soon
as the boc^ F F have passed
through the ring, the jaws
D D are drawn open by the
weight of the load, the sluckle
is thus released and the
hooks catch on the top of
the ring G. As an addi-
tional precaution there is a
projecting rim at 0, to catch
the hooks if by some chance
they should fail to act at the
tc^.
Stopping Oear. — The dis-
engaging appliances just de-
scribed are designed with a
view of correcting the efibcts
of an overwind, by preventing
the ascending cage from being
dashed against the pulley,
and then possibly falling
down the sh^t. But they in
no way protect the descend-
ing cage from bumping on
the bottom ; even if they
did, the old motto stiU holds
good that " prevention is
better than cure," especially
as detaching hooks have been
known to fail.
Engineers have therefore
been anxious to obtain some
means of automatically stop-
ping the cage before it is
raised too far, and many
appliances for this purpose
have been invented.
Three which were exhibited at the Paris Exhibition of 1889
deeerve special mention, as they are in regular use at large and
important minee — viz., the automatic speed-checkers and stopping-
gearsof Reumauz, Yilliera, and 'Wiry.* M. Reiimaux lays down
pp. 949-956, and plaUs.
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HOISTING OR WINDING. 425
tlie priiidple that too much confidenoe must not be placed in an
applifmce which is only occEiBionatly called into action ; and his self-
acting speed-checker comee into play at every wind. When the
cage in its aacent passes a point 30 m. below the surface, a tappet
apon the revolving indicator lifts a valve, and so putA one end of a
[ostoD valve into communication with the atmosphere ; as eteam
or compressed air is pressing upon the other end, the valve
moves and shuts off steam from the engine almost completely.
The same release of pressure causes aDother valve to rise and let
steam into the cylinder working the brake. If the engine-man,
after turning on steam again, is again inattentive and allows the
cage to be drawn up x feet above the landing, a second tappet upon
the indicator once more causes the steam to be shut off; and a
third tappet, by opening an exhaust passage, makes another valve
drop and turn steam on to the i^linder controUing the brake.
M. Beumauz's appliance is attached to all the winding machines
used at the extraisive Lens collieries, whether they are worked
by steam or compressed air.
Villiers' apparatus is somewhat complicated, and cannot be
properly understood without a figure. Suffice it to say that a
nut travelling upon a screw sets gearing in motion and so
actuates a friction clutoh ; this brings into play a regulator which
opens a valve and lets out the compressed air from under a piston
holding up a weight. The weight in dropping shuts off steam
and puts on the brake. A. second part of the apparatus, working
in a different manner, produces like effects ', and, lastly, if the cage
is wound up a certain distance above the landing, it strikes a
catch which releases another counterpoise, the descent of which
also causes the brake to act.
With W^r/s contrivance the connecti<m between the winding
drum and the checking apparatus is again effected by gearing
and levera instead of fluid pressure. When the cage has reached
a certain point near the surface, a nut travelling upon a
screw lifts a rod carrying a pawl, which reets upon the teeth
of a wheel turning round by clockwork. If the pawl rises more
quickly than the wheel revolves, it lifts it, and by means of
levers brings the steam-brake into action ; the speed of winding
is thus diminished. The clockw<a-k is so regulated that the brake
is not made to act unless the speed is excessive. To prevent
danger from a slow overwind, a second rod acts in any case and
turns steam on to the brake cylinder if the cage is drawn up too
high.
Bertram* and Oobboldf have invented automatic stopping
appliances which depend upon the action of a ball governor,
• " On Ovenrindlng and Its Prevention," Train. Fed. Intt. M.E., voL I.,
1890, p. Si-
t "A Patent Apporal
OverwlndiDg at Uines."-
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426 ORB AND STONE-MINING.
connected t^ gearing with the main driving ahaft of the winding
Faschke and KSstner's appamtus, osed at many mines in the
Freiberg district, is spoken of favourably. It automatically
shuts off steam and pate on the brake, not only when the cage is
being drawn up too high, bat also when the speed is ezcesfdve.
Safety Catohea. — Much ingenuity has been displajred by
TEtious inventon during the last fifty years, with ^e object
of providing some form of catch which wiU come into {day if the
rope breaks, grip the guides or conductorB, and prevent the cage
or skip from falling down the shaft.
Many of them are actuated by a. spring, and one form has
already been figured in describing the cage used on the Oomstock
lode (Figs. 481 and 483).
While the load is hanging from the rope, the spring a sib
drawn into the position shown by the dotted lines by the lifting
bar r, the eye of which is figured in its two positions. The bar
c is drawn up at the same time, and the teeth 1 1 are held apart
and kept clear of the guide. If the rope breaks, the spring
forces down the bar b and with it c ; the teeth jam into the
wooden conductor, and the cage is arrested and held firmly.
The safety catch used for the De Beeis skip (Fig. 473)
likewise depends upon the action of springs.
An objection often urged against safety catches is that they
occasioneJly come into play when not wanted, and that owing to
rust and disuse they get out of order, and sometimes fail to
act at the proper moment ; for these reasons tbey are less popular
on this side of the Channel than on the Continent. Many
engineers, rather than trust to contrivances which may possibly
fail under the conditions met with in mines, are more indined to
put their faith in the following precautions :
1. Inaoiiiif; an excellent quality of rope, bj S[fAog to a maker of
good repnte and peijiDg a fur price.
2. lfs<^eat minute examiDation of the rope.
3. Testing i^ecea of the rope at regular interrala,
4. Protection ol the rope from the action of the atmospbete or
acldaloiiH Wftter in the mine by a Boitabte grease.
5. Catting off the end of the rope where it is attached to the cage
and re-maldng the attanhment at regular intervals.
6. macarding the rope after it has been In use a certain fixed
time, even if ft is apparently soDud as fat as outward exam-
ination can show.
The same feeling seems to have existed among the members of the
Royal Conunission upon Accidents in Mines,* for tbey say, " We
have, however, examined several varieties of the safety cages in
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HOISTING OR WINDING 427
ose, as well as those exhibited at euccessire lutemationaJ Exhibi-
tions, and we have considered a large number recently described
and figured in an elaborate paper by Heir Selbach,* and we are
unable tocome to the conclusion that any one of them is a trust-
worthy safeguard against accideuta." This opinion does not settle
the question ; for, on the other bemd, I may refer to the con-
ctuaons which Menzalt draws from the study cf oareFully pre-
pared official Btotistics. Though far from asserting that existing
safety catches are perfect, he shows that on the whole they did
useful work during the seven years 1884-1890 in the coal and ore
mines of Saxony, and he considers that they should be applied to
all cages used for winding men.
Springs. — The rope suffers the greatest strain at the com-
mencement of the ascent of the cage. There is always a little slack
rope, which is taken up as the winding begins, and this leads to the
danger of a sudden strain being put upon the rope every time that
it b^ins to lift the cage, especially in cases where winding is being
carried on rapidly. In order to spare the r<^ from a shook <^
this kind and cause it to take the weight gradually, a steel or
india-rubber spring may be interposed between the cage and the
rope, arranged in such a fashion that the first action of the pull
is merely to compress it; finally, when the compreeeion has
reached a certain stage the cage will be lifted. The bearings of
winding pulleys are sometimes supported by springs with a
similar object in view.
Testing Bopes. — The Commeutiy Fourchambault Mining
Company keep a useful record of the state of their winding ropes
by testing them at regular intervals. Once ia every six months
a piece of rope about 9 feet long is cut off and sent to a powerful
testing machine, called the antheximeter, capable of breaking a
new wire rope more than a inches in diameter. The machine
registers upon paper not only the force required to break the rope,
but also its elongation previous to rupture. By comparing the
results obtained in this way, the gradual deterioiation of the'rope
fnmi wear can be followed with great precision. J
In the mines of the Dortmund district, no winding-rope can be
used for raising and lowering men until it has been carefully
tested in a manner prescribed by the Government authorities. A
piece of the rope one metre in length is cut off, and the tensile
strength and the flexibility of each wire are determined, with
the exception of wires forming cores.
Fneumatio Hoisting. — The most novel hoisting apparatus
• ZeOtekr. far das 3.- IT.- und 3.- Watn, vol. xxvlii. 18S0. B. Abhand-
hmgen, p. i.
t "Die in den Jahren 1884-1890^ beim sAcheischen Bergban voree-
kommenaQ Brttche Ton FBrderseilea, Schonketten und derKlatohen.''—
JaiTli.f.d.S.-u.H.-Wc$eiti.K. Sae/uen, 1891, p. 39.
} Comptu Rendu* Mount}*, Soe. Jnd. Min. 1891, p. 357.
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4i8 OBE AND STONE-MINING.
is that of M. Blanohet, wliich was regularly at work in the
Hottinguer shaft at £pinac in Prance for some years. M.
Blanchet fixed in the shaft a. large pipe with a piston, from which
wtM Biupended a cage oarrying waggons. By exhausting the air
above the piston the load was gradually forced tip by the atmo-
Suberic preesnre below it. The Hottinguer shaft is 660 yards
eep, and the mpe was 5 feet 3 inches in diameter, made up of
a sacoeseion of oylindeiB of sheet-iron about ^ inch thick and
4 feet 4 inches high, joined by flanges and bolts. The 485 rings
composing the long pipe wdghed altogether 41 S statue tons. The
cage had nine decks, and arrangements were made for unloading
three at a time ; each waggon held half a ton, so that the total
useful load was 4} tons. The speed of houiting was 30 feet per
second. If two hoisting pipes are conueoted, the dead weights
may be made to babutce each other, and the power required is
simply that which is necessary to oTeroome the weight of the
useful load. All the men preferred the pneumatic hoist to the
ordinary cage for descending and asoendiog the mine, and were
regularly lowered and raised by it. The advantages claimed by
M. Blanchet for this system are — (i) the possibility of hoisting
from depths at which rope-winding would no longer be ptacticable ;
(z) getting rid of the costly ropes and dangeio ooimected with
rope-winding ; {3) better utilisation of the engine powers (4)
improvement of the ventilation and diminution of the amount of
fire-damp. At the present time Blanchet'a apparatus ia no longer
employed, but the disuse of the pneumatic method is in no way
due to any difficulty in making it work satisfactorily,*
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( 4Z9 )
CHAPTER IX.
HBAINAOE.
Snrisce dr^nage — Dams — Drainage tnnnela — BIphoDs — Balling water by
windiDg maohluerr — Pumpa worked bj engines at the anrface —
Rittinger pump — CounteTbalaiiGes — Boohkoltz's r^eneratar — Roaaig-
ueuz'B coutrivtuoe — QitcheB— Pumps worked by engines plao^
below gronnd — "Duty" — "Slip" — Co-operatlTe pumping.
7^ mineral having been raised to the surface, the task of the
minar might appear to be at an end ; but this is not the case, for
it is further necessary that he should keep his mine free from
water and foul air. These tvo indispensable operations of drain-
ing and ventilating require special appliances, which often add
considerably to the general cost of mining.
Surfboe Water. — As far as possible the miner should endeavour
to prevent the entry of water both at the surface and under-
ground, and so escape the unnecessary expense of pumping it up.
In Borne instances a good deal can be done in this direction ; for it
has been abundantly proved, in many cases, that the bulk of the
water with which the miner is burdened is merely the result of
the percolation of the rain falling in the district. The e£Ebct
even of a prolonged rainfall is not usually felt at once, for it
takes time for the water to find its way tiirough minute cracks
and crevices in the ground and reach the workings. In lime,
stone districts, however, the rain may find large channels eaten
out by atmospheric agencies, and affect mines at a depth of a
couple of hundred yards within twenty-four hours after it has
fallen.
It often happens that the mineral was quarried near the surface
before underground mining was resorted to, and in that case there
is always the danger of the old open pits forming a sink, so to
say, which will cc^eot water from the neighbourhood and let a
considerable quantity percolate into the workings. To avoid
such an objectionable state of things, the surface must be drained ;
special care is imperative where the ground is cracked by sub-
sidenoes, and the neighbouring streams should be examined and
the water carried along in launders or other safer channels, if
their beds cannot be made stanch by filling the fissures with
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43© ORE AND STONE-MIKING.
WLen worldog Tinder the sea or a river, a rich lode muet not
tempt the miner to carry on fais work too far. At Wheal Cock,
near Bt. Just in Cornwall, the miners working in some overhand
Btopes actually bored more than one hole through to the sea-
bottom. They wera well aware of the proximity of the ocean,
for tbey could hear the boulders crashing sgainst each other in
stormy weather, and tbey had wooden plugs ready, which they
drove into the holes when they actually tapped sea water. But
it was a dangerous experiment, and though in this case the rocks
are ao bard and compact that the amount of percolation is smaU,
a narrow wall only four feet thick between the sea and the
workings cannot be left without fear of trouble and danger from
water above.
Duns. — In addition to preventing the access of water from
the surface, it is advisable to cut off underground inflows ae far
as practicable. In the chapter upon supporting ground, imperme-
able linings of shafts and levels have been described, and where water
can be shut out by tubbing or by coffering, the mine-owner ia
saved the constant expense of pumping ; indeed, be is sometimes
thus enabled to work deposits which he would not be able to
reach if he had to fi^t against the enormous streams issuing
from certain strata. Water from adjacent abandoned workings
is shut out by dams — that is to say, artificial stoppings — placed
in levels or ahafta, They may be made of timb^, brickwork,
masoniy or concrete, and, when intended for temporary purposea,
of iron.
In erecting a dam the first oonsideiaticai is the choice of a
suitable place, for it is useless to take the trouble to put in a
stanch stopping unlees the ground Is firm enough to support it,
and free enough from oracks to
Pig. 49t. prevent the water behind it from
'j^jW////,. finding its way round to the
^MU^lM////... front.
If the ground is thoroughly
strong, a ^un may be put in by
cutting a recess in the sides Of
the level, as represented by
Fig. 491,* and stopping the
water back by a wall made of
horizontal balks of timber. Oak
is usually chosen for the purpose.
Before the timber is pat in, the
rock is very carefully dressed nntil the surface is perfectly
smooth, and ready to receive a similar surface of wooa. Each
balk is wedged up against the side jnst in the same way as a
wedging curb, and the jointe between the separate balks are
caulked.
* Callon, LaXnrt* on Mining, toL U., plate Ixzri.
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DRAINAGE.
431
For heavier praesures the spheric&l dam ia available; it is
coDBtructed of wooden logs pUced loogitudiaally ajid wedged up
very tightly. A wooden dam of thiB kind haa the advantage that
it will yield a L'ttle if there are movements of the ground, whereas
a dam constructed of bricks might become cncked and leak so
badly as to be almost useless ; the wooden dam is alao more
eatdly repaired. Oak, pine, and fir are all employed for
making dams ; the two latter are sometimes prefen^ to the
former, because they are more easily wedged. The following
account of a spherical dam is based upon a description written by
■ (Kgs. 492 to 495).
Fio. 493-
MMIM 1
(doll i
V 1 1 1 1 1
1 1 1 1 1
M+
11 1 1 Ml
\
0 l_J_
li
A nail isfixeduponacroBS-pieceinthemiddleof the level, about
13 feet (7 m.) from the proposed outer face of the dam, and the sidee
of the levelare trimmed smooth with the greatest care along planes
which would intersect in this point as a centre. Pieces of timber
ara cut in the form of truncated pyramids, the four faces of which
converge to a centre agreeing with that chosen underground ;
they are fitted together at the surface, with the horizontal
joints arranged along the lines of the same great circles of the
sphere and the veiiiical joints alternating. When the logs have
been duly fitted, the work of putting them in is begun. Tarred
canvas is placed upon the floor of ^e level and the first row of
• JahrbvehfUr den Sera, vnd Hotten- Maim auf dot Jahr 1841, Freiberg.
Combes, TraaidiVBi^mtaiion det Mintt. Fails, 18S4, vol. li., page 121,
and plates.
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432 ORE AND STONE-MINING.
pieces laid down ; the last piece acts as a keystone and is driven
in with a sledge. One of the pieces of the second layer has a
hole bored through it bo as to let off any water during the progress
of the work. When themiddleof the dun ia reached, aflanged cast-
iron pipe is put in as a man-hole, and theotherrowBareboiltup to
the roof, which has been covered with tarred canvas ; a hole is bored
through one of the pieces of the uppermost row but one and fur-
nished with a bent pipe, which serves to cany off the air at the top
when the dam is finally doeed. The joints between the logs are
made watertight by driving in wedges around them obliquely ; the
first wedges are of pine, the next are of hard wood, and the final
set are of iron. A coating of cement, made of cart-grease, tar
KiG. 494.
and slacked lime, completes the outer face of the dam. The
miners then close the water-hole with a plug made of beech, and
after retiring through the man-hole, draw into it a huge wooden
stopper. The water is allowed to rise, and in due course some
passes out by the air pipe ; the air-hote is then plugged, and the
m^de face of the dam is wedged up in the same maimer as
the outside. When exposed to considerable pressure a spherical
dam of this kind is found to slide inwards a little. One which
was put in at Churprinz Mine, Freiberg, shifted 19^ inches
(0.50 m.) in the first fourteen hours after it had been dosed, and
23^ inchee altogether in the first ten days ; after that the motion
was exceedingly slow, in fact, almost imperceptible ; but it did
not absolutely cease for several years.
Fig. 496* is a dam in an abandoned shaft, intended to shut
• Gallon, Ledaret on Siiiiing, vol. ii., plate liiri., fig. 409.
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DHAINAGE. 433
off any possible influx of water into the adjacent workings in
case the tubbing should fail. It consists of a strong arch of
maeoary, covered by a thick layer of clay and a pavement of
stones. The clay vill keep the dam stanch even if the maaonty
becomes slightly cracked from
movements of the ground, Fig. 496.
and the object of the stone
pavement is to prevent the
clay from being washed away
suddenly in the event of a
targe crack being formed. The
vertical pipe serves to carry
down the water during the
erection of the dam.
A temporary dam is some-
timee required close to a shaft,
in order to keep back the
water of the mine, and pre-
vent it from drowning the
pumps whUe they are being
repaired. A strong and
tightly-fitting hinged door
may suffice for the purpose;
in the Fumess district the
door-frame is set in a very
massive structure of concrete,
brickwork and steel rails. A
large pipe is put in at the
bottom and fitted with a good
valve, which enables the watei-
to be let out gradually when
the pumps are once more ao*>.e
ready for work. ' o'-s o i a ^METRca ,
In spite of all precautions 01 a a « s a t s b' I'o I'i fl tarcEi
the miner genendly has to
contend with water which percolates into the workings. Four
methods of getting rid of it are available — vis., draina^ tunnels,
siphons, winding machinery and pumps.
DBAIHAGE TUIflfEltB. — An adit, day-level, or sough, is a
nearly horizontal tunnel with one end opening at the surface,
allowing the water to drain away naturally. In hilly countries
mines are often worked entirely by adits, and even for the deeper
workings the adit presents several advantages: it lessens the
quantity of water percolating into them ; it cuminishes the height
to whidi the water has to be pumped ; if the contour of the sur-
face permits it, its outflow may be utilised for producing water
Sower; and la^y, it affords a natural discharge for water used in
riving hydiauHc engines underground. On account of thsae
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434 OBE ASD STONE-MINING.
very impcatant adntntageB, some long and costly adits have been
driven in certain metalliferouB districts.
Thus in the Harti, the Emeet Augustus adit or drainage tunnel,
(" Ernst August StoUn ") has been driven & distance of nearly 6 J
miles into t^e Olansthal district. The total length of the adit,
including its bisnchee, is no less tlian 14 miles. It interaects
many of the lodes at a depth of 400 yards ^m the surface. The
total cost of this adit is estimated at ^£85,500.*
Another long adit is the celebrated*' Rothachonbergsr StoUn,"
which uDwaters some of the most important mines at Freiberg in
Saxony, The length of the main or trunk adit is more than 8^
miles; the gradient of the greater part of it is only i'i8 inch in
100 j'ards. Sranches of this adit among the mines are more
tiiaxL 16 miles in length, so that the total length of the main
tunnel with its ramifications amounts to about 25 miles. Most
of the mines are now drained by it to a depth of 250 to 300 yards.
The cost of the main tunnel was ^^3591334, or nearly -£24 per
yard, but this includes the cost of eight shafts, heavy expenses
for pumping from theee shafts, the walling of the adit for j mile,
and all general ezpensee. The length of time occupied in iMving
this adit was thirty-three years.
The " Kaiser Joeef Erbetolln," in Hungary, is another remark-
able mining tunnel, which was commenced in 1782 and com-
pleted in 187S, at a total cost of 4,599,000 floiins. It is 10^
miles in length, extending from the river Gran to the town
of Schemnitz, where it intersects the lodes at depths vary-
ing from 300 to 600 yards according to the contour of the
surface.
In Bohemia I may mention the " Eaiser Josef II." adit which
drains the Pribram mines. The length from the mouth to the
Stefan shaft is 4^ miles, and the side branches bring up the
total length to 13^ miles.
The great adit of the Mansfeld copper mines was begun in
1809, and was seventy years in course <a construction. It reaches
from Friedeburg on the Saale to Eisleben. The first part was
driven across the measures, and is, in fact, a crosscut, and it was
then continued along the strike of the cupriferous seam. The
total length is now 31 miles (33,900 m.). All the workings below
its level, extending for a distance of more than 11 miles (iS 1"^^.),
have their water pumped into it. The adit was driven vdai
a riseof i in 7200 (} inch in 100 yards). It is 9 feet id iuchee
high {3 m^, and 6 feetaoroes (1-85 m.), inthemiddle where it is
widest. The bottom part, 5 feet 8 inches in height, was carefully
kept in the Bothliegendee so as to prevent percolation into the work-
ings. Cross-timbers (apreaders) were put in about 5 feet above the
a the Upper Bsrti Ifinea,"
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DBAXKAOE. 435
floor and serve to support a ^gle line of rails and a gangway of
planks.*
The adit at MontepoDi.t in Sardinia, recently finished, is 3^
miles (6 HI.) in length, and relieves the mine of its water for an
additional depth of about 160 feet (50 m.).
The great County adit in Cornwall was driven for the purpose
of draining the Gwenn&p copper mines, and it was pushed on
to Bedruth. This adit differs from thoee just mentioned by
the (act that it commences in the mining district itself, and
though the length of all the dHvages amounts to more than 30
milee, the water from the most distant mine does not run more
than 6 miles before reaching daylight. The average depth is
only 70 or 80 yards from the surface. In fact this great adit,
though a work of great utility when the Gwennap district was in
a flourishing condition, is merely a network of shallow tunnels,
often driven along the lodes themselves, and therefore for bold-
ness of execution cannot for one moment be compared to the
great adits in Oermany and Hungary.
The Blackett level in Northumberland is an adit which has
been driven a distance of about 4I miles, and which will have
to be extended about 2 miles further before arriving at Allen-
heads. Its depth from the surface at that place will be about 300
yards.
The main part of the Halkyn tunnel In Flintshire has now
reached a total length of 4 miles. The branch which goes oat to
fihosesmor Mine is nearly half a mile long and a second branch
has been commenced. The greatest depth from the surface is 230
yards, and the average depth under Halkyn Mountain about 21S
yards. The length and depth of the adit are not remarkable ; but
the quantity of water dischai^ed is a matter of interest and impor-
tance. It is estimated that this adit is ngw discharging 15
million gallons or 66,000 tons of water in 34 hours, although the
outflow IS purely natural, for no mines are pumping water into it,
It is easy to undsi'stand that the Khoeesmor Mine, though
provided with powerful pumpiog machinery, was unable to cope
with the springe it encountered.
In the United Kingdom, where the land and the minerals are
parcelled out among various owners, an undertaking of this
kind requires a special Act of Parliament, for otherwise one
obstinate proprietor might bar the way altogether, or mines
drained by the adit might refuse to pay for the advantages they
received. Before the Halkyn tunnel was driven, the area which
appeared likely to be benefited was duly determined, and the
• Der Smfo'iehieferbergbau vml der HiUtenbttrith zvr Ferorietiuna der
gtaomitiunJuinent m den beidtn Kreuender Preiui. I'rov. Sadten. Halle
an der Saale, 18S0, page 48.
t Pellatf, "I Prcf^eui nelle Indnatiie Hlneiarie e HiDeralnrgiohe
Italians," IndtulrUi, vol. v., 1891, p. 637.
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436 ORE AND STONE-MININa.
minea Qow worked within it h&ve to pay a royalty to the
tunnel company for every ton of ore they rai^e,
Fired by the success of the Halkyn adit, which has proved a
luc^ investment for the shareholders, a company has lately
commenced driving a similar tunnel ia the Llaoarmon district.
The United States may fairly boast of the Sutro Tunnel, which
enters the workings on the Comstock lode at a depth of 1700 feet
from the surface. Work was begun on a small scale in October
1869, and the tunnel was "holed" into the workings of the
Savage Mine in July 1878. The length of the main tunnel is
3§ miles, and the cost of excavating it and timbering it ap to the
date of its completion, September i, 1878, was $1,367,577. To
this must be added $396,734 for enlarging the heading, 1384,834
for cutting a drainage channel at the bottom of the tunnel and
lining it with wooden launders or drain boxes, and the cost of
repairs $43,441, making the total cost of the main tunnel up to
October 1S81, $2,096,566. This sum does not include the expenses
of management of the company.*
The size of the adit at first was 10 feet high clear and 15^ feet
wide ; but after 366 yards had been driven the dimensions were
reduced to 6 feet high cleax by 5 feet wide.
In theoriginalschemeit was proposed to sink four shafts and ex-
pedite the work by having nine points of attack ; however, this plan
could not he carried out. Thefirst two shafts weresunk down to the
levelof the tunnel, but the quantity of water mat with proved such
an obstacle that the ttmnel was practically driven entir^y from
one end.
Work with machine drills waa begun in April 1874, and the
height of the heading was raised to 9^ feet, and the width to 13
feet, both outside the timber. In 1875 and 1876 the monthly
progress was on &a average 308^ feet. Uuch of the tunnel,
indeed 45-5 per cent, of the total length, had to be timbered.
In addition to the main tunnel there are branches along the
course of the lode. In October 1880, the length of the north
branch was 4403 feet, and that of the south branch 41 14 feet.
Both branches are 8 feet in width by 7 in height dear.
The quantity of water running out daOy in 1879 was 12,000
tons, at a temperature of 123° F. (50*5 0.)when leaving the mouth
of the tunnel. All this wat«r woidd otherwise have been pumped
to the surface, at a cost estimated at $3000 a-day.
The obstacles to the progress of the work were very great ; not
only was the heat extreme, but swelling ground was encountered
which snapped th« strongest timber. Thanks, however, to the
untiring energy of Mr. Adolph Suteo, the di^culties were at
* Bliot Lord, ** Comatook Hinlog and Miosra" Monogrc^ht of the U. 8.
Oeol. Survey, vol. iv., p. 342. WaBhinBton, 1883. Tbeie Ic an arror of
$4000 either In odb of the itema or in the total ; bat J give the fiKnree as
they stand in the Eeport.— a i. N. F.
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DRAINAGE. 437
last aucceesfully overoome, and this great work will long remain
OS a monument to his foresight, skill, t,nd patient pertinacity.
The Atlontio-Padfic tunnel, which was commenced in 188a and
then stopped for a time, is intended to pierce the heart of the
Bodky Mountains, under Qrey's Peak, Colorado. It will be
driven from both sides 0! the watershed, and wiU have a total
length of 4I milee from end to end.
SIPHON'S. — Siphons are used for draining mines in a few
special cases in which the barrier orer which the water has to be
raised is very decidedly lees than 33 feet.
The workings of a shallow mine in North Wale« are kept clear
of water by a siphon made of ij-inch gas-pipe. At the orown
there is an iron tank full of water, the contents of which
can be ran into the siphon by a 3-in(di pipe in order to start
it.
At Mountfield gypsum mine, in Sussex, the water is brought to
the shaft from the neighbourhood of the working-face, a distance
of 300 yards, by a siphon also made of i^-inch gas-pipe. It has
two branches, hot only one is working at a time. The water
ia lifted a height of 22 feet. When the water in the workings sinks,
so that there is a danger of the siphon running dry, the foreman
moves alever which brings npad of india-rubber against the outlet
of the pipe, and so keepe it full and ready to act the next time it is
wanted. A force pump is set up at the far end of the workings
for filling the dphon if by any chance the water has run out.
WINDIlta MACHIHEBY.— When a mine cannot be
drained by tunnels or siphouu, it is necessary to raise the water
mechanically, either to the sui-face, or at all events to an adit
through wluch it can flow out naturally. If the quantity is not
excessive, it is often «»>nvenient to use the winding machinery,
and draw up the water in special buckets {toaier-barrtla) or tanks.
The bucket may be tilted ovei' on reaching the surface, or it may
be emptied by opening a valve at the bottom.
This means of raising water is commonly adopted in sinking
shafts, when it may be desirable to wait till the whole or a
portion of the pit is completed, befor« putting in the final pump-
ing machinery. The water is usually lifted by hand into the
bucket or tank, an operation involving a good deal of labour.
Some of the baling may be avoided by collecting as much as
possible of the inflow in a cistern above the bottom, and drawing
off its contents by a hose into the bucket. This device is of no
use tac the water actually at the bottom, but baling may be dis-
pensed with even in this case by the adoption of an ingenious
arrangement invented by Mr. Galloway, and applied very success-
fully by him in sinking a shaft near Cardiff* (Figs. 497 and
498).
* "Slnkins Apfdlanoes at LUwbradaob," IVani, Smth WuUa Intl. Eag,
vol. itL, iS^ p. II7-
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438
ORE AND STONE-MINING.
FtOB. 497, 498.
By metuis of a pamp at the snrfnoe, the air is oooatantly being
exhaosted from a pipe, which descenda the shaft and termio&tee
in a long piece of flexible hoee provided with & etopoock. Wheo
the cylindrical water^barrel has been lowered to the bottom of the
shaft and is standing with its base in
water, the flexible hoae ia quickly
attacfaed to it at the point it by an
instantaneous coupling, and the cock is
turned. Water is at once sucked up
through the valve b, and as soon as the
?B.uge-glass m shows that it has reached
the desired height, the stopcock is
cloeed and the hoee uncoupled. On
arriving at the top of the pit, the water-
barrel is lowered on to a trolley carry-
ing a projecting conical block of wood,
which knocks up the valve and allows
the contents to run out.
It was possible with the aid of this
contrivance, while sinking a shaft in
hard sandstone at the rate of 5 to 5}
yards per week, to cope with an influx
of 5000 gallons (22*7 cubic metres) of
water per hour at the bottom.
A water-barrel can be filled auto-
matically, when it can be made to
plunge into a deep cistern or collect-
a, door for entering barrel "« P'' (f*.""?)- Mr <3»l]oway'8
if raqnired ; 6, flit oast- "^angement is shown by Figs. 499 and
Iron valve attached to ths 500. The former represents his anto-
flliindle h; c d, bottom matic water-tank with one aide partly
m^ofaey^y'^'h''T' '^'^^- « is the winding-rope, 6 the
aniversal ° Join? \tZ<^. *^^' ^^^^ " guided in its descent and
ment ; I, water-pipe, pro- ascent by the studs e (Fig, 500) run-
vided at the end t with ning upon the guide ropes e. At the
a coupling to which the garface the tank is further steadied by
^J'er'gl^g:."^'"'' Side grooves, made erf angl^iron d,
which clasp the studs. When the tank
is lowered into the oistern, the valve k opens of itself ajid lets the
water rush in. Itis then wound upto the top, where the short lever
at o comes in contact with the piece of timber ;> ,- the rod attached
to the valve is lifted, and the water rushes out by the sloping
mouth / into the wooden trough or launder m. The bar p is
movable about the point q, but it is kept down by the weight u
attached to the chain a ; tie one of the piecee of timber to which
the fixed guides are fastened, and lastly, u> is the suspending bow
which passes quite round the tank and fonns a projecting loop at
the bottom. This bow protects the bottom of the tank while it
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DRAINAGE. 439
IB Btauding in the cist«ni. The tank holds 212 gallons (963
litres), and cau be drawn up 24 times an hour from a depth of
190 yards ; it is therefore capable of raising 5000 gallonB (227
cubic metres) in that time.
The arrangement just described was employed by Mr. Qalloway
when sinking, but it is equally available as a permanent method
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440 ORE AND STONE-MINING.
of drainagft when the qoantity of w&ter is not considerable,
!nie water is allowed to accumulate in a sump at the bottom
of the shaft during the day-time, for instance, and at night, when
no mineral is being wound, the ordinary cage is taken off and
the water-bairel substituted for it.
Fis. 500. The water-barrel is also useful as an
auxiliary, when the ordinary pumping
machinery of a mine is unable to cope
with some unusual influx of water, or
haa to be stopped for repairs. It is
not necessary t^ adopt the constroction
shown in the £gure, though that is a
particularly advantageous one. The
vessel for receiving the water and
bringing it up is sometimes made like
a large mine waggon ; it is drawn op
in the cage, like a " tub " of miner^,
and is discharged at some point in
close proximity to the pit-top. At the
Van mine a tub of this kind holds
about 320 gallons (i culno metre). Ab
a makeshift, an ordinary mine-skip
may be turned into a water-barrel by
fixing a wooden box inside it with a
valve in the bottom.
Automatic emptying and filling is
also obtainable where the mine is
worked by inclines or "slopes," and
the arrangement used by Mr. Bowden*
{Figs. 501 to 503) has the merit of
allowing several tanks to be used in
the place of a single large one, which
might be too unwieldy for the miae.
Each tank ha« an iron door at the rear
end cpening inwards, and a wooden
door at the front end opening out-
wards. The front door is attached
to the back door by an iron rod, so
that it is held down as long as the back
door ia shut ; however, the back door can open independently of
the front door, because the rod has a sliding lirik at the rear end.
The tipping or dumping is effected by the small wheels above the
rear axles. They have a wider gauge than the regular wheels,
and as each tank comes up to the surface, they are taken by an
upper set of mils and tilt up the rear end. If the track upon
wluch they travel has sufGcient gradient towards the " slope," the
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DRAINAGE.
441
tanks will run down of ttemaelves, after they Iiave emptjed their
contents into the trough at the top.
PUHFS. — We now come to the main division of the subject of
drainage, for the standard method of extracting water from
underground workings is by some form of pump.
The varieties of pumps used in mines are numerous. In small
sinkings, hand-pumps, either direct-acting or rotary, may be
applied ; steam-^jet pumps, on the principle of the Qiffitrd
injector, and pulsometers are also used, but when we examine the
Fios. SOI, 501.
permanent machinery erected at large mines
depth, we find that the prevailing types of pumps are few.
Tbey may be classified, according to the situation of the engine
working the pumps, into ;
L LUting pumps and force pomps narked by power transniltted by
rods noiu an eDgliie at tbe Boifoce or in the upper working!.
II. Fcoce pninpa woikod diiect from an engine Immedutel; sttachad
to them at or near the bottom of the walkings.
Class Z. — Engine at or near the SurfiEtoe, Power Trans-
mitted by Bods.
We may consider the subject under the following four heads :
) Accessory anangemeuts ; cooiiterbalances, regenerators, catches.
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442 ORE AND STONE-MININa.
(a) Motors. — The engine may be driven by wind, compreseed
air, water, electricity, ateam, or petroleum, (i) Air. — Windmills
bave the disadvantage, which is often fatal, that the power is not
conetant ; the Bame may be said of water power derived tram
brooks and rivers, which sometimes dry up; but the two cases
are different. Streams dry up slowly and gradually, whilst air
cuireute spring up or die away suddenly. By erecting an
auziliaiy steam engine, which can be set to woii if the wind
fails, the evil is overcome ; and this remedy is adopted at the
Mona mines in Anglesey, where a windmill has been in uoe for
many years for working pumps. It raises water from a depth
of So &Ltboms at the rate of about 90 gallons a minute. As the
site of the mine on FarjB Mountain iti breezy, there is wind
enough to work the mill for about one-half of the time pumping
is required. A very lai^ saving has thus been effected in the
coal bills.
(2) Water. — Water power was for a long period the principal
agent employed in draining mines, and it is still of the greatest
use in many districts, reservoirs being constructed to collect and
store the rainfaU. Some idea of the scale upon which worics of
this kind ore conducted will be gathered from the following
figures relating to the Hartz mines.* In 1868 there were
"sixty-seven reservoirs, covering an area of 604 acres, and
having a total storage capacity of 336 millions of cubic feet,"
The total length of the various leats, races, and other water-
courses, including the six principal adits, is about 170 statute
"I'l"! The net power extracted is reckoned at 1870 horse-power,
but less than one-fourth of this is used for pumping.
Water power is applied to pumping machinery by water-
wheels, turbines, and rotary or non-rotary water-pressure engines.
Excepting in the case of the latter, the rotary motion has to be
converted into a reciprocating motion by a crank ; and further-
more with turbines, the speed must be reduced very considerably
by intermediate gearing.
Overshot wheels are the commonest forms of prime movers
for working pumps by water-power ; they are frequently from
40 to 50 feet in diameter, and at Great Laxey Mine, in the
Isle of Man, one of the wheels is no less than 73 feet 6
inches in diameter, and 6 feet in the breast. The power is con-
veyed from the water-wheel by a connecting rod to a quadrant
or " bob," like a bell-crank, placed above uie shaft, and when,
owing to the contour of the ground, the wheel has to be erected
at a distance, it is often connected to the bob by the so-called
" flat rods," which are beams of wood, bars of iron, or pieces of
wire rope. They are supported by pulleys or upright oscillating
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DRAINAGE. 443
beams, and tra.vel backwards or forworda with the motioti of the
cnutk.
Wat6r-|a:«Beure et^pues share with turlnnes tiie adTantage of
being able to utilise any amount of fall, and the direct-acting
water- pressure engine can be applied immediately to the main
rod of the pumps.
(3) iS't«Hn is, however, the power used par «KM2fenoe for workinv
pumping machinery, and the great inventions of Newoomen and
Watt owed their birth to the necessities of mines, which could no
longer be drained by the water power available on the spot.
The principal type of engine is that known as the Cornish
engine; it is a aingl&acting condensing beam engine, working
expansively, havii^ the number of strokes regulated by an
arrangement called a cataract. The cylinder of the Cornish
engine is sometimes inverted and stands over the shaft, the main
rod of the pumps being attached directly to the piston-rod. This
type of engine, known as the Bull engine in Cornwall, dispenses
with the heavy beam, but it has the great disadvantage <^
obstructing the mouth of the shaft. This objection is quite
enough to forbid its use under ordinary circumstances. On the
other hand, the mere reversal of the cylinder or cyhndera, while
retaining the beam, is often resorted to on account of the
advantage it gives in greater stability and diminished cost of the
engine-house.
A disadvBJitage of the ComiBh engine is the fact that when it
works with a high rate of expansion, there are great shocks and
jars to all tbe parte of the machinery. The heavy mass of rods
and its connections is started with a jerk, and naturally all the
joints must euSer.
The compound engine, invented by Woolf and tried many yeara
ago in Cornwall, starts more gradually and causes less strain upon
the pomp-rods and machinery generally. The cylinders may be
placed one above the other, or aide by side. At Ernst lY. shaft,
Mansfeld, there are three cylinders placed side by aide across the
line of the beam, the high-preBsure cylinder in the middle between
the two low-pressure cylinders. The three piston-rods are attached
to a crosshead which is connected to the beam. The cylindezs
are inverted.
Kley, of Bonn, has constructed compound engines with steam
acting on both aides of the pistons. He makes the excess of the
weight of the rod over that of the counterbalances sufficient
to raise only half the weight of the water and to overcome the
friction ; and then in the descending stroke of the rod the steam
again acts upcm the pistons and so makes up for the insufficiency
in weight. As the steam acts upon both sides of the piston, tbe
same amount is consumed, it is true ; but a smaller cylinder will
do the work, and the original ccst of the engine is lessened.
Fly-wheels have the advantage of setting the pumps and mala
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444 ORE AND STONE-MINING.
rod in motion without the iojurioas jerk which is Inseparable
from the Cornish engine worked at & lugh rate of expansion,
beeidea reducing the risks of damage if a piston-rod breaks.
Kley has put up several pumping en^es in Belgium, France,
and Qermany, of 30 to 560 horse-power, with a fly-wheel which
servee solely to regulate the stroke of the piston, so that the
crank always stope before or after the dead point till the cataract
starts another stroke. The machines are double-acting compound
beam engines.
M. Ouinotte, the well-known Belgian engineer, also adopts the
fly-wheel, and the machines he has erected at Mariemont and else-
where are singlfrActing rotary eAgines with one cylinder. The
peculiarity of his fly-wheel is that he can weight it in any way he
pleases; and he so overcomes the difficulty which occurs in other
rotary machines of its being impossible to work them below a certain
speed. His object is to make the speed slow at the beginning and
FiQ. 504.
end d the stroke, so as to avoid the injurious shocks to the
valves and machinery generally from sudden starts and stoppages.
The cylinders of a pumping engine may be placed horizontally,
an arrangement which ^ecta a decided savi^ in the cost of
foundations and in that of the engine- house. IDie engine lately
erected at the Otto lY. shaft at Manefeld (Fig, 504) is a
horizontal double-acting compound engine with a fly-wheel,
working two pump-rods by means of quadrants. A is the high-
pressure cylinder, B the low-pressure cylinder, 0 the fly-whte),
D and E are quadrants, connected by F, which raise and lower the
two rods Q and H, The cylinder A is 5 feet i^ inches (1*590
m.) in diameter, and B 8 feet i^ inches (z'480 m.). The stroke
of the eogine is 8 feet 8} inches (2660 m.}, and the fly-wheel
makes 1 1^ revolutions per minute. When working at this epeed
it is reckoned that it raises 3531 gall<m3 (16 cubic metres) of
water per minute, a total height of 906 feet (376*35 m.). The
waterisGalt,and has aspecific gravity of I'lj. Each rod works
apump at the bottom, with a fixed hollow plunger 17I inches (705
mm.^ in diameter and a moving " pole case," which lifts the water to
aheight of 463 feet (141*1 m.). Here the work is taken up by a
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DRAIfTAGE. 445
Bittinger pump with plungere of 37^ inches (700 mm.) and 21}
iochee (540 mm.), and the water is raised by it to the adit level,
an additional height of 443 feet (i^S'^S ™-)- "^^^ stroke of the
rods is 2 metres. When the full power of the engine is not
required, one rod can be disconnected and the other is balanced
by an Bccumulator.
At Dieponlinchen, near Stolberg, an engine of similar construc-
tion has been put up within the last few years, the dimensions of
the two cylinders being almost the same as those adopted at
Mansfeld. The problem at Diepenlinohen is to raise 2640 gallons
fi2 cubic metres) of water per minute from a depth of 328 yards
300 m.).
The compound engine, with its two cylinders placed tandem
fashion horizontally, is largely used by Davey, whose principal im-
provement consists in bis patent difierentiol valve gear, which
combines the action of a cataract with that of a slide valve.
(4) Petroieum. — Where coal is very expensive owing to the cost
of carriage, a petroleum engine may be a convenient source of
power for pumping on a snuul scale.
{b) BodjB. — Having discussed the principal forms of engines
used for pumping at mines, it now remains to consider
how their power is applied to the pumps themselves. Via. 505.
The usual mode of transmission is by rods made ^ ^
of wood, wrought iron, or steel. ^ '
Wooden rods are commonly constructed in this
country of pitch-pine beams of square section, united by ~— .
plates of iron or mild steel {strappinff plates, a, b, c,
F^, 505), which are held together by bolts, the butt end 1 ',
of one beam being brought against the butt end of the ' -
next. Other forms of joints, such as the scarf joint,
are met with.
The iron and steel rods are either solid bars of round
iron or steel, or beams built up from angle-iron or
angle-steel, so as to obtain the desired stiETness without
undue weight. It is proposed to use Mannesmann
seamless steel tubes, which can be rolled in lengths of
70 feet, as rods for pumps.
The long beam, made up of a succession of pieces,
constitutes what is called the main rod or spear-rod.
It hangs down the shaft, either from the end of the
beam 5t the engine, or from a quadrant such as is
shown in E^. 504, when the cylinder of the pumping engine
is horizontal. In <nrder to fmveat it from vibrating ddeways,
it has to be guided; wooden rods are guided by cross bars of
timber placed in the shaft, and they are protected from wear by
pieces m plank {UntTig board*), which are renewed from time to
ume. The round iron or steel rods are kept in position 1:^
suitable collars fixed upon timber or metal supports.
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446
ORE AND STONE-MINING.
If the Bhaft is inclined, as so often happens in Tein-mining, the
main rod has to be supported at suitable interrals by cylinders of
cast iron or steel, knovn as " shaft rolls." The roller turns upon
a spindle as the main rod moveB up and down (Fig. 539}.
The bane of some mining districts, such as Cornwall, is the
varying indinatioQ of many of the pumping shafts, which have
bew sank along the dip of
Fio. 506.
I of this
kind it is necessary to make
bends in the main rod cor-
responding to the crooked-
ness of the shaft. Four
methods of making an
angle in the rod are : (i)
the V-bob;*(2)the fend-
off bob; (3) the running'
loop ; (4) hydraulic pistons.
The V-bob, as its name
impUes (Figs. 506 and 507),
is a V-lJke frame, some-
thing like a beU'Crank, in-
terposed between the ends
of the two rods. The two arms of the V are made of strong
beams of timber strengthened by iron plates b and 0, and con-
nected by two straps a, which prevent their being ptUled apart.
The arms are arranged so that each is at right angles to the
Fia. 50S.
adjacent end of the rod at half stroke. At the point of the V
there is a strong pin d lying in brasses, about which the bob
moves as a centre. It is usual to make the arms at least 20
* Tbls llgDie and ssreral of the othars relating to pampa are copied, br
permisBioD, from a paper on "Comlah Uine Drainage," b; Uitchell and
Letchet. Ibrtt/third Ann. Btp. B. Comteali Ri. Soe, Falmonth, 1S75.
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DRAINAGE.
447
inches long for each foot of the stroke. Therefore for a stroke
of 9 feet, the length of each arm would be 9 x i|, or 15 feet.
A fend-off beam will be understood from Fig. 508, which
is an example taken from Crenver and Abraham Mine in
Cornwall. It is a long beam, strengthened b^ tte-rods, moving
about a strong pin working in a block. The Cornish rale is to
make the beam 2^ times as long as the stroke.
The running loop (Figs. 509 and 510) is sometimes used to
Bare the expense of cutting out the large recess (plat) which is
required in the case of a V-bob or a fend-off beam. The two parts
of the main rod, e and d, are connected by two loops of wrought
Fia. 509.
Fig. siq
Fio. 511.
iron, e, of vhich one only can be shown in the side elevation.
Each loop passes round the two pins, which are the axles o?
die two wheels. The wheels run upon flat bars of wrought-iron,
/, laid upon the sleepers, b, which are supported by the strong
crosB-betu«rs, a a.
West and Darlington effect the change of direction in the rods
by two rams or plungers, working in cylinders connected at the
bottom (Fig. 511). The plunger a in going down raises the
plunger 0, to which the main rod of the pumps is attached by a
croBshead and two mde strape. There is a valve at c, through
which the plunger can draw in a little water to make up for any
loss through the stuffing boxes,
(c) Ptunps. — ^The main rod, which has just been described, is
used for transmitting the motion of the engine to a pump or
several pumps in the shaft. These pumps are of two deecrip-
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448 ORE AND STONE-MINING.
tione: (i) lifting pumps; (z) force-pumps. The lifting ptunp,
or drawing lift (Fig. 512), consists of the wind-bore or eaction
pipe, the cl&ck-piece or valve-box, the clack-sent piece, the working
barrel, the bucket with its rod and the column.
The wlad-bore, or snore-piece, as it is sometimes called, is a
(^linder of cast-iron, terminating in an egg-shaped or a flat bottom,
with a number of holes through which the water is sucked up
into the pump.
The clack-piece is a short C7linder of cast iroa with a flat side
door fastened on by bolts, the object of which is to enable the
valve to be taken out and renewed. It receives the seat on which
a clack or valve works.
The clack seat-piece is not always used; but it is often put
in as ft matter of precaution, in case the regular valve ebonld
accidentally fail whUe the pumps are under water. If a mishap
of this kind occurs, a special clack can be lowered on to the
clack seat-piece, acd the pump cau be worked with it temporarily.
The working barrel is a cast-iron cylinder, carefully bored so
that the bucket may work in it smoothly and exactly ; occasionoUy
it is bushed with brass.
The bucket is merely a moving valve, consisting usually of a
hollow cylinder of cast iron, surrounded by a band of leather or
gutta-percha, and attached to a rod through which it receives its
reciprocating motion. The seat, called the " form," may be made
for a single valve or a double valve. The " form " shown in Figs,
513 and 514 is made for one valve, and it is held by a stout rod
with two forks or " prongJL" The mode of attachment of the
prong a to the form b, by the so-called half-moons c and cotters,
is evident from Figs. 514 and 515. When there are two valves
Hid form is mode as shown by Fig. 516 or Fig. 517, and the rod,
now called a " sword," is attached by a central blade which passes
iihrough a corresponding slot in the middle rib.
The valve itself is made of a fiat piece of leather riveted
'between two iron plates and fastened at one end (Fig. 513) by
spikes or bolts, or of two similar semi-circular pieces of leather
attached at the circumference (Fig, 516) or in the middle of the
form (Fig. 517). In either cue there is a baud of leather or
gutta-percha round the form which makes the bucket fit exactly
in the working barrel. This band is cut out in the shape of a seg-
ment, such as is shown in £^. 51S, and is then bent round the
fcB-m and kept in its place by an iron hoop or ring. Leather
is usually employed, and is sometimes made from buf&lo hide, in
order to obtain great durability ; with gutta-percha there is the
advantage of being able to utilise a worn-out band in making
a new one. After it has been st^tened in hot water and well
kneaded up with a little fresh gutta-percha, to supply the waste,
it can be rolled out in a proper mould into a band of the
desired shape. Bichardson's composition consists largely of
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DRAINAGE.
449
gutta-percha, and makes a durable and economioal pump-booket.
The bucket is attached to the rod by a square sliding clasp and a
cotter. The bucket-prong, or sword, has a little projecting ridge
(Fig. 514) which fits into a corresponding raceaa in the end of the
rod ; when the clasp has been drawn over and the key inserted,
the joint is complete. The actual rod iteelf may be of wood or
Fia. 513.
Fio. S13. Fia. 514,
iron, and it may either work inside the column or outside.
Fig. 512 shows the commoner method in this country, but both here
and on the otiier side of the Atlantic the second plan ia employed.
Fig. 519 represents a lifting pump used in mines on the Com-
stock lode.* S is the windbore or suction pipe; V the fixed
clack or valve ; F the bucket, with its valve v, moving in the
working bonel. The rod to which it is fixed passes through the
tofiht
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450 ORE AND STONE-MINING.
staffing-box g, and is connected to the vooden rod R. The
column of pipes, made of riveted sheet iron, through which the
watec is lifted, is shown by C. Three xheet-iron cylinders
riveted together form one section. Each section is yro-
vided at both ends with a cast-iron flange, and two
adjacent sections are fastened together by bolte. The cast-iroD
pieces H carry the stuffing-box and join the column to the
working barrel. Figs. 530 and 511 represent the mode of attadi-
ment of two sections, and also the manner in which the column is
held in the shaft. Lap-welded sheet-iron pipes may take the
place of the riveted pipes of the figure.
The columns of pumps in this country are generally made of
cast-iron pipes with flanges ; the standard length is 9 feet. The
joint is made by inserting a ring of sheet iron, which has been
wound round with coarse flannel soaked in tar, and tightening
the bolta. A more perfect and durable connection i^ obtained if
the flanges are properly faced and provided with a recess for an india-
rubber or a gutta-percna washer. Pipes of sheet iron and steel have
the advantage of lightness, an important matter when transport
is expensive, and it may be hqied that pipes of rolled steel
made by the Manneemann process will be available for the
rising mains of mine-pumps ; fewer joints will be required, and
the column will be lighter and lees troublesome in every way.
Wooden pumpa have not disappeared in countries where
timber is abundant and metal expensive ; the rising mains are
formed of trees bored along the centre. Wood is also used in
certain cases when the mine water is corrosive ; thus at the Parys
mine, Anglesey, where the water is highly cupriferous, pumps of
this kind have to be employed. The wooden pipes made by
Wyckofi" & Son, of Elmira, N.Y., are bored white pine logs turned
outside, strengthened by a band of hoop-iron wound around spir-
ally, and coated with asphalt. Pipes of this description are made
with bores up to 1 6 inches in diameter, and are capable of resisting a
pressure of 160 lbs. per square inch, or a head of water of 370 feet.
The disadvantage of the arrangement shown in Fig. 519 is
that if a bucket fails, whilst the stuffing-box happens to be sub-
merged, the " lift is lost," in other words the pump is utterly
useless; whilst with the ordinary system (Fig. 513), the bucket
can be drawn out and " geared " once more. To remedy this
defect, a working barrel and a clack-piece may be inserted in
the column ; a new rod and bucket con then be lowered into it,
and made to work until the water is sufficiently mastered for
the old bucket to be changed.
On the other hand, the stuffing-box arrangement can claim
the advantage of making the buckets last longer. No doubt the
reason of this is that the stuffing-box acts as a guide to the rod,
and prevents irregular friction of the bucket against the sides of
the working barrel.
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DRAINAGE. 45 >
The force-pump used in mines, known aa the
f lunger pump (Fig. 522). consists of a solid piston
flutter), working through a. stuffing-box in a
long cylinder standing upon a special casting
known as the H-piece. This is so called because
it is made up of two parallel cylinders, like the
Fig. 533.
aRfffa
n
two upright limbs of the letter H, which are
connected by a horizontal pipe, like the cross-bar.
The H-piec« is often faulty from presenting a
path with very sudden turns ; all angles should
be rounded off, so as to make the passage of the
water as easy as possible. The H-piece has a
valve immediately above the wind-bore or suction-
pipe. Id the figure the wind-bore is flat^nded
because it is resting in a cistern. Above the
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45a ORE Aia> STON&MINING.
H-piece cornea the door-piece with acother valve, and then a
aanes of pipes, the " oolmnn," generally of cast inm, but soine-
times, as already stated, of wrought iron.
The action is easily understood. When the plunger is moved
apwards, water is drawn in by the wind-bore, and when the
[dunger descends, the bottom clack closes, the top clack opeoB,
and the water is forced up into the colamn. The plungo: is
a hollow cylinder of cast iron, accurately tnmed outside. Usoslly
one end of a wooden rod is passed through it and wedged tightly
at the bottom, and the other end is atta^ed to the main rod by
staples and glands, bnng kept at a proper distanoe from it l^ a
piece of timber.
The plunger pump can claim superiority over the lifting pomp
fw several reasons : it is less likely to get out of order, and, if it
doee begin to fail, its shortcomingB are more quickly perceived and
more easily remedied. The first advantage is almost self-evident ;
one need only picture the leathern rim of the backet rubbing
against the eddes of the working barrel, and the solid plunger
sliding up and down through the stufiiDg box, to feel convinced
titat it is more difficult to keep the former tight than the latter.
Practical experience ocmfirms this a priori reasoning. Whan the
water contams sand in suspension, the bucket wears out rapidly
and has go be changed at frequent intervals; consequently ib
most be performing much of its work in an inefficient manner.
Incipient faults of the bucket causing but a slight diminution in
tiie quantity of water raised are likely to pass unnoticed, whereas
a le^y stuffing-box is at once detected. This latter defect can be
qteedily cured by the man in charge of the pumpe (pitman), who
luts simply to take a spanner and tighten up a few nuts, whilst
changing a bucket of an ordinary lifting pump involves the with-
drawal of the whole length of rods to which it in attached, an
operation causing some trouble and requiring time. Lastly, the
efficient manner in which the plunger does its work renders it
suitable for higher lifts than the bucket.
In the majority of cases a drawing lift is fixed at the bottom^
because it can be lengthened as the shaft is deepened, a process
going on continually in vein-mining, and further because it can
be worked with lees fear of a complete break-down than a plunger,
if the water rises in the mine and submerges the working
parts. This bottom pump lifts the water into a cistern in which
stands the wind-bore of the plunger pump (Fig. 521), and the
remainder of the pumping ia done in stages. The first plunger
forces the water up a column into another dstem, some 60 or
more yards higher, where a second plunger continues the work
and raises the water into a third cistern, and so on until it
reaches the surface or the adit.
Pumping is usually done in stages because it is not always
easy to Veep the joints tight when the pressure of the water is-
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DRAIKAOE. 453
vcoy great. The difficulty is nowadaTs far lesa than it was for-
merly, and columns are made even aa mooh as 600 metres (656
yards) in height vertioally.
The subject of P>ui^ would not be complete without a few
words upon valves. The common leather clacks used in some
buckets have already been tniefly mentioned. The valves of
pumps may be divided into two classes — viz., clai^ and metal
valves.
Figs. 523 and 534 represent a simple valre called the Hake's
mondi valve. It oonsists of the seat, slightly conical below so as
to fit into the proper recess in a casting, such as the H-piece or
olack-pieoe, and the moving flap made of a piece of strong leather
between two platea of iron, held firmly together by copper rivets.
The flap is attached to the " tail " of the seat by bolts, and the
pliable leather not only makee the hinge, but ensures a water-tight
contact.
Fio. 523. FiQ. 535. Fia. 537.
M
td
In the butterfly valve (Figs. 515 and 526) there ore two semi-
circular lids or flaps. In a clack known as " Jan Ham's clack,"
the two lids are hinged on the outside and took towards each other
instead of from one another.
A valve which has given great satisfaction in Cornwall is
known as Trelease'e valve (Fig8.527 and 528). Its peculiarity is the
great freedom of motion given to it by its hinge. The seat has
two upright " risers " with slots in which the pin of the clack can
move up and down. The valve is of metel with a sheet of leather
I riveted on for making it water-tight. It will be readily under-
stood that, as th^ leather is not playing the part of a binge, a
valve of this description will last longer than those described
previously ; it can also be used with a bucket.
If the water is corrosive, aa too frequently happens in mines,
the seat and the valve are made of brass, gun-metal, or bronze,
and a recess is made in the circumference of the seat for tl.e
insertion of wood, which will last longer for the " beat " than
metal.
Teague's noiselesa valve (Figs. 529 to 531) is made by inserting
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454
ORB AKD STONE-MINIKG.
Fia. 539.
FiQ. S3'-
a small valve into the flap of a Hake's month valve. It is said to
remove entirely the concusdon met with in large pumps.
AmoDg the metallic valves the most important is the doable-
beat valve, the object of which is to afford as
great a, waterway as possible with a small rise
of the valve. A double-beat valve may be briefly
described as a bell with a large hole at the top,
and surfaces of contact at top and bottom ; when
the bell is raised by the pressure underneath,
there are two passages by which the water can
escape, one sideways, all round the bottom, and
one upwards, through the top. It was invented
originally for steam engines, and long after-
wEude was applied to pumps. The valve
shown in Figs. 532 to 534 consists of a shell a
connected to a rio^ t by radial arms c; The
letters b indicate atrengtheoing ribs on the out-
side of the shell ; they -are inclined a little Bo
that the stream of water passing through the
valve may cause it to turn shghtly each time it
is opened, and beat in a difllerent position. This
ensures even wear and keeps the valve water-tight.
The two " beats," that is to say the two surfaces of contact, maiked
nand m, are rings of white me^, gutta-percha, or india-rubber fltted
in grooves in the two seats q and /; r is a guide for the centr^
ring t which is bushed with brass, indicated by the black line ;
o and p are radial arms on which slides the brass bushing of the
lower ring of the shell, and they are stayed by the cylindrical piece
Flo. 532.
i'la. S33-
Fic- 534.
« and the ring I, The rise of the valve is limited byj, which is kept
in its place by the screw e, held by a nut in the cross-bar d; h h
is the diamber in which the valve works. Fig. 533 shows the valve
open, and Fig. 534 is an elevation of the valve and lower seat,
which will greatly assist in making its mode of action plun.
The number of beats is sometimes increased to three or four.
Bittinger Pnmp. — The £ittinger pump is an important
variety which has been introduced on the Continent, for reme-
dying one of the defects of the ordinary pumping plant— viz.,
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DEAINAGE. 455
ita iatenuittenb action. The ComiBh engine makes & sudden
start, tbe "outdoor" end of tlie beam goes up, aad with it
the main rod and the plangera; then comes a pause, and all
this time no useful work of raising water is being done. Lastly,
the beam and the main rod slowly descend and the plungers
force up water. The actual work of pumping proper is accom-
plished in a short part of the time occupied by a double stroke.
It is evident that a smaller engine doiof^ work continuously
would be just as effective as the large one acting at intervals.
The Bittinger pump (Figs. 535 and 536) may be described briefly
as a difierential pump, with two hollow plungers, one fixed and
the other moving. A fi is the moving part of the pump, consisting
of the air-chamber and plunger case A, the hollow plunger B,
and the quadruple-beat valve C. It is drawn up and down by the
aide rods D D. E is the top of a lower section of the rising
Diain, and F & large pipe constituting a cistern. O is a valve
at the bottom of the plunger case H. At the top there is the
second hollow plunger I, which is fixed, working through a
stuffing-box in A, and K is the rising main; L is the space
for air.
When the moving part A B ascends C closes, and water is drawn
up into I and K ; at the same time Q opens, and water makes ita
way through it into H. When A B descends the space above G is
diminished, C rises, and water flows into A. The descent of A B
increases the space above the valve 0, but as the plunger B is
larger than the plunger I, more water flows into A than it can
accommodate ; consequently some of it must ascend through S.,
Tbe amount so passing will depend upon the relative diameters
of tbe two plungers. In considering the quantity pumped during
each stroke, it must be observed that the two hollow plungers
displace just as much as if they were solid, because they are
always filled with water ; therefore the effective area of each is:
Let P and p represent these areas of the large and the small
plunger respectively and L the length of the stroke. When A B
makes its upetroke, a quantity of water equal to L p is drawn up
into K ; during the down-stroke the amount rising into K is equal
to the difference of the volumes displaced by the two plungers —
viz., L P - L ;> or L (P -y). If it is desired that the delivery
shall be the same at each stroke, whether up or down, we must
Fr<Mn this we get,
Lj. = L(P-j>).
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456 ORB AND STONE-MINING.
In other worde, the ana of the section ctf the small plunger must be
Fig. S35. FiO. 536.
K I
— r
one-half that of the large one. This is carried ont in practice ; in
one of the large pumps at Mansfeld the diameter of the lairge
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DHAINAGE.
457
plonger is 0-90 m, (2ft. ii^in.), and that of the bduUI one
o'64 m. (2ft. im,). The areas are therefore 0*63 sq. m. and
o'3» Kj. m.
It is possible to dispense with the main rod altogether by
interpoBiog the rising main between the two plungers, one being
placed at Uie bottom of the shaft and the other at the top ; but
this plan doee not meet with general approval, because, although
it saves the cost of a main rod, it subjects a long column of pipes
alternately to tension and compression, with the result of trouUe
from leabigee.
(d) Aooeseorr Arrangements : aounterbalanoes, CatohM,
Ao.
aounterbalanoes. — The weight of the main rod, with its
strapping plates or other connections, is generally greater than is
required for the purpose of forcing up the column of water in
the pnmps, and overcoming the friction of the various parts of the
Via. S37-
machinery. It becomes necessary, therefore, both in order to
avoid useless vraete of power in lifting the main rod, and to prevent
its descending with too great a speed, to counterbalance so much of
the weight as is not actually employed in doing useful work. The
commonest form of counterbalance is a " bob " such as shown in
^^-537- It is a beam (2 (£ working upon pivots (7w^e(nM)i,whioh
lie in brasses ; the end e, called the nose of the bob, is attached to
the main rod hy a long connecting rod, whilst f is a box which
is filled, or partly filled, with old iron or stones. The beam is
stiffened by the upright " king post " a, and the straps b 0 ; ffjf
are staples and glands fastening the casting m, to the beam, and i
is the " bishop's head " at the top of the " king post." Cast-iron
beams, precisely like the beams of an engine, fulfil the same offioe
at some mines, and the oounterbidance is a huge piece of cast-iron
(Fig. 544). There is usually a " balance bob " at the surface, and
others are fixed at intervals in large recesses (&[]&-p2ate) cut out
in the aide of the shaft.
West and Darlington have introduced the counterbalance shown
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458
ORE AND STONE-MINING.
JD Fig. 53S ; a is a plunger attached to the main rod of the pump
by a set-off, 6 iB a horisoDtal pipe connecting the two plunger- cases,
e is the second plu&ger catrj^ing the box /, which is weighted &»
required ; g g are its guides, ^e slight losses of water are made
up from the pipe A, which communicates with a cistern, or, when
this method cannot be used, a little plunger j will draw up and
force in the necessary supply. Fig. 539 represents the same kind
of counterpoise applied to an inclined shaft.
Fia. 538.
Hydraulic counterpoises have been found to be the most
advantageous with the huge pumping engines of 1000 horse-power
at Manafeld. Probably at no mines in the world has the question
of pumping on a large scale been more carefully studied than in
that district,* and the engineers have come to the conclusion that
it is advisable to make their wrought-iron rods act invariably by
tension and never by compression. They therefore have a weight
at the end of the rod, and the rod + the weight must be so
balanced that the machine has no work but that of raising the
water and overcoming the friction.
* Hammer, " Die neaeren WaaBerbaltuDgen beim Mansfelder Knpfer-
MhieterbeivbaD," Her W. aUgemtine Iltuttdie Btrgmannetag, in Halie, tkuie,
t8it9. FuUxridit und Verkan^ungtn, p. 39.
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DRAINAGE.
459
The special counterpoise kDown as the Bochkoltz r^enerator
(Fig. 540 *) ia added to some pumps for the purpose of uding the
main tod oa beginning its downwu^ course, when it has not only
to overcome the weight of the water in the column, bat also to
open the clacks. The regenerator has been applied on the
assumption that at this moment there is an excess of work, because
the pressure of the water on the under side of the veive is acting
upon a smaller area than the crater on the upper side, the
difference being the area of the beat. Bochkoltz attaches a very
heavy weight to the counterpoise at the surface, at right angles
to the beaJn. If the balance beam in Fig. 537 is reversed, so
that the king-post hangs down-
wards, and if a weight is fixed to fiq. 540,
the bis hop's head, you have a
Bochkoltz regenerator. In Fig. 540
A ia the cylinder of a Bull engine ;
B, the piston-rod ; 0, the main
rod of the pamps; I>, the beam;
E, a weighted box ; F, a weighted
box.
Suppose that the plunger has
finished its upstroke. The Boch-
koltz weight now hangs like a pen-
dulum about to begin an oscillation,
and in descending under the action
of gravity it assists the main rod
in its woi^ i as it apj»x)achee a
vertical position its influence b
lessened, and finally it creates a
resistance when it has to be raised
again. It does good at the begin-
ning of the stroke by helping the
weight of the rods, and it does good
at &6 end of the stroke by dimin-
ishing the velocity graduaUy,and by
bringing the pumping machinery to a standstill without a shock.
The idea that there is an excess of pressure upon the clacks at
first is not borne out by experiments, but the regenerator has
the advantage of enabling the engine to be started at a higher
speed than would be safe without it; the mean speed is thus
increased, and the engine is able to make a larger number of
strokes safely per minute.
The same effect as that of the Bochkoltz regenerator is
obtained in a very simple manner by M. Rossigneux,! who gives
the beam a curved bearing surface which rolls upon a plane
* Gallon, L<ttuTti on Minimi, Atlae, toI. iL, plate Izxiii.
f Sxporitiim Univtrtelie ile 1889. Natire »t(r la Sotiili Animyme de«
HouiU^a dt Montrambrrt et dt la Biravdiirf, Saint-Etieiine, 1SS9, p. 53.
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460
ORE AND BTONE-MININO,
(FigB. 541 »nd 543). By this device tha ratio of tba lengths of the
two amiR of the beams is alwa^ varying : a* the commeikcemait
of the down-stroke, the weight of the main rod ia acting with a
long leverage compored with that of the coimterpoise, at ttie end
of the Btroke the conditions are revereed. The ezcjees of pressure
due to the length of leverage aooeleratee the motion at first, and
then, as this leverage diminishes, the weight of the counterpoise
becomes more and more felt and the rod ia stopped gradually.
The wme effects occur during the ujvstroke of the main rod.
The countarpoiae begins by accelerating the motion, then ila
Fio. 54 1.
influence is less and leas felt until the rod stops. Soesigneox's
system can be applied to any existing beam with componLtivdy little
expense ; indeed it was first adopted in the case of a Cornish
pumping engine, which was becoming incapable of coping with an
additional influx of water, owiug to the deepening of the shaft.
The variable counterpoise rendered it possible to ino^ase the
number of strokes per minute with safety, and so enabled the
engine to do more work.
Catches. — Frovision must be made for a possible breakage ol
the main rod, which might have ver^' dijiastrouB results for the
mine. If such an accident happened without any of the ordinary
safeguards, the beam would come down with great force and
play havoc in the engine-house, whilst the main rod dropping in
the shaft would be sure to do damage to the pumps.
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DBAIKAOE. 461
The indoor end of the engioe-beam is therefore fitted vith two
projecting ai'ms of iron, which come down so as almost to toach
two strong beams at every stroke ; if a breakage happens, they
arrest the motion of the engino-betun before it has bad time to do
an; harm.
Catches are also fixed in the shaft ; they are strong beams of
timber e c (Fig. 543, and S, Figs. 546 to 550),
stretching across the shaft and resting in good „
" hitches," with the main rod a working between '
them. The wings b b are attached to the main rod
by straps with bolts (" staples and glands "), and are
so adjusted that the end of the wing almost touches
the catch at the end of ea«h down-stroke of the rod.
A catch of this kind limits the possible fall of the
main rod to the length of the stroke. Oatches
placed in the reverse direction are also useful in
supplementing the action of those placed upon the
beam in the engine-house.
Lastly, it must be recollected that hirge pumping
machinery requires tackle capable of dealing with
the heavy weights which have to be moved. High
shears erected at the top of the pit enable pieces
of main rod, often 60 feet in length, or heavy
H-pieces, to be raised and lowered by means of a
eirong hempen or steel rope worked by a capstan
moved by men, or better by a drum driven by a
special steam engine.
Hammer, of Mansfeld, strongly recommends that every large
pumping engine should have its hydraulic prees for lifting the
beam, when changing the brasses or making repairs, the alight
extra cost being amply repaid by the convenience of having such
an appliance always ready at hand ; a similar prees for raising the
heavy fly-wheel, if used, is likewise desirable.
Pumping Plant. — After these general considerations about
pumps, it will be well to take an example and show how the various
pariaare combined in order to cany on the work of drainage.
The seven Figures, 544 to 550, illustrate the pumping plant at
Shakemantle Mine in the Forest of I>ean, erected by Mr. Ibomas
Smith, the maiwger, to whom I am indebted for drawings, and
for verbal explanations on the spot.
The shaft b oval, zz feet 6 inches by 11 feet 6 inches; it is
" steened " or walled from top to bottom with sandstone, the stone
being set in ordinary mortar where the ground is dry, and in
hydraulic mortar where it is wet. The engine is a low-pressure
condensing beam engine, with a 70-inch (I'So m.) cylinder A,
working, with a 12-feet (3*65 m.) stroke, the heavy fly-wheel B,
which can be driven at as slow a speed as three revolutions a
minute. The main rod 0 is made of round wrought iron,
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462 ORE AND STONE-MINING.
Fia. 544.
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DRAINAGE.
8 inches in diameter at the top,
diminished gradually to 6 inches
at the bottom. D ia a beam or
"boh" for conaterbalanciDg so
much of their weight as is not
required for raising the water
and overcoming friction. There
are three plungers, each 27
inches (o'686 m.) in diameter,
arranged in a straight line with
the main rod; this is managed by
attaching the rod to a croes-head
B (Rg. S47) above each plunger,
and bringing down two rods F F,
one on each side of the H-piece
O, to a lower crossbead E' — from
which the main rod is contioued
in the same line as before. The
other parts are as follows: H,
plunger; I, csst-iron supporting
girder, resting upou cast-iron
shoes built into the sides of the
shaft; J, cistern made of cast-
iron plates bolted together, with
the joints lined with cement, and
screwed down to the top of the
column K; L {Fig. 546), spring
to steady the cistern; M, hang-
ing rods which have the same
object ; N, windbore in the cis-
tern ; 0, windbore at the bottom
of the shaft ; F, the door for
changing the bottom valve ; Q,
door for changing the top valve ;
B, door to a butterfly valve,
which keeps up the water in the
column while the valve at Q is
being changed ; S, beams across
the shaft to catch the rod by the
cross-plates T in case of a break-
age ; 17, air-chamber,
lihe general substitution of
iroa for timber effects a great
economy of space in the shaft;
the fly-wheel, which prevents any
jerk at the beginning of a stroke,
the air-chambers, and the ar-
rangement of the plungers in the
ORE AND STONE-MININa.
Flo. 546. Fia. 547.
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/////////////////>('
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466 OBB A24D STONE-MININO.
same stnught line as the loda, aJl aid in aeotiring & freedom from
ribration and a smoothnefls of motion which are highly conducive
tu good working. The result is that the drynees of the shaft and
the abaenoe of noise Kre remarkable, considering the large quantat;
of water lifted — viz., nearly looo g«llone {4^ cubic metres^ (^
water per minute when the engine is going at the speed of only 4
atrokee. Some idea will be gained of the massiveness of the pit-
work by mentioning that the H-piece alone weighs 16} tons.
01«M II. — Forae Pumps worked by an Engine at or
near the bottom of the Workings. — The advantage of being
able to dispeiiee with the ponderous main rod, its counterpoises,
catches and sucoeesion of plungers, io only too obvious, to say
nothing of economy in first cost and more speedy erection ; and
this second class of pumping machinery is being more and more
largely used where otrcumstanoes admit of its adoption. The
objection to the system is the danger of the machinery being
" drowned," and so rendered useless, by any unusual influx of
water, because a mishap of this kind would involve the erection of
new pumping plant for draining the mine. Where the engine is
at the surface, such a contingeticy as the drowning or partial
drowning of the workings is not irremediable. It was this con-
sideration which led the authorities at Hansfeld to have some of
their engines above ground ; for in that district huge cavities full
of water {SohltOtm) may be encountered unexpectedly at any
moment and for a time overpower all the available pumping plant.
On the other hand, at Hechemich, under different conditions, the
Oomish engines at the surface have been given up and replaced
with great advantage by underground machines.
Underground pumping engines are divided, according to the
source of power, into those worked by steam, water, compressed
air, electricity or by petroleum engines.
Steam. — At the present day we have to deal mainly with
steam engines when speaking of pumping on a large scale. The
steam may be generated above or below ground; if the boilers are
plaoed above ground, great care has to be taken in jacketing the
steam pipe which comes down the shaft, in order to prevent loss
of heat by radiation and the consequent unprofitable expenditure
of fuel.
It is necessary to mention two types of engines which are most
commonly met with: (i)horizoQtal engines without fiy-wheel ; (3)
horizontal engines with fly-wheel. The engine may be simple or
compound, but the latter class is naturally more in repute.
(i) In this first class comes the difibrential engine of Davey,
which has been already described in speaking of engines used at
the surface. Instead of working the pump by the intermediary
of the bob and the main rod, the plunger is attached in a line
with the piston-rod, and forces the water up the column. Tlie
height to which such a coliynn can be taken is governed by the
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DRAINAGE. 467
strength of th« pipes, and the difficulties of making joints
Buffidently tight to resist pressures measured b^ hundreds of
pounds to the square inch. At 1a LouviSre Mine in Belgium
the column is 630 yards (^76 m.) high, and prolnbly there are
few much higher than this at the present day ; such a column
means a pressure at the bottom of 55*6 atmospheres, or 81 7 pounds
to the square inch.
Davey provides for the possible drowning d the lower part of a
mine, through an inrush or unusual influx of water, by placing
his main engine at a sufficient height above the bottom to render
it practically safe from flooding ; he liflB the water to it from
the bottom by means of an auxiliary pump. This latter pump is
worked by hydraulic power transmitted by pipes, and it will
|>erforoi its work efficiently eren if it is drowned.
There are many of these direct-acting pumps without fly-wheels
in the market, such as those of Knowles, Tangye and Worthing-
"ton, but want of space prevents my describing them.
(3) Fly-wheels are added in order to secure that smooth and
T^nlar action which is so conducive to the eflicienoy of machinray.
Figs. 551 and 552 give a general idea of one of the under-
ground pumping engines at Mansfeld. It is a horizontal com-
pound engine working four plungers or rams. A is the higb-
preeenre cylinder, 2 feet 11} inches (900 mm.) in diameter, B the
low-{n«ssure cylinder, 3 feet 9^ inches (1*150 m.) in diameter, 0
is the fly-wfae^ D and E are crossheads connected by the rods F
and 0, and similarly H and I are crossheads connected by the
rods J and K; LM NO are the four rams, each 93 inches (o'35 m.)
in diameter, having the same stroke as the pistons of the en-
(^e, 4 feet ij indaee (1*250 m,), P P" and Q Q' are delivery
pipes leading to a main deliv^y pipe B, which goes to the rising
main in the shaft. When the engine is working at the rate <^
30 revolutions per minute, it is calculated that it raises 1540
gallons (7 cubic metres) of water per minute to a total height of
'612 feet (i86'5m.). The specific gravity of the water is i'3.
This type of pumping engine is likewise found satisfactory on
aU points at Mechernich. When a Cornish engine was employed
the consumption of coal was 4 kil. per effective horse-power,
measured in water actually raised, now it is only 2*1 kil. A strong
door is erected outside the pump-room, which can be closed so as
to shut it off for some time even when the water rises considerably.
Biedler bases his system of constructing pumps upon some of
the same considerations as those which guided Bni^hardt and
Weiss in improving air-compreesors ; he works his valves by
gearing, and so secures the advantage of driving his pumps at very
much higher speeds than are possible with valves which open and
-clcee of themselves. As in the case of the air-compressor, this
rapidity of fitr<^e enables a smaller machine to be empl<^«d for
■doing a given amount of work.
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468
ORE AND STONE-MININQ.
Fut»(meUr.—Tbe pulsometer (Rg. 553) is » foiT" of pump
used ftt mines for heighte act exceeding 70 or 80 feet, and neually
odI; for tempontry purposeB. The steam arTiving by the pipe e
preesee directly upon the eurface of the nater in a chamber a.
10=^
^
and drives it through an opening d and a valve into the rising
main. When the discharge is all but complete, the steam
passing with the water through d creates a disturbance and la
consequence is condensed ; this causes a ball-valve / at the
top <a the adjoining chamber to pass over and shut off
the entry of the steam. The steam now enters the adjoining
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DEAINAGE. 469
chamber, and, acting as before, forces its contents up the
rising main. In the meantime the steam in the first
chamber is being condensed, and its phice is taken by water
drawn up the suction pipe
c ; d is an air-chamber, Fio. 553.
g g are the suction-valvee,
and h h Hto[» which arrest
them. The action is re-
peated first in one chamber
-and then in the other, so
that a continuous stream
of water is forced up.
The pu]someter -viilX
pump muddy or gritty
water, it occupies little
space, is very portable, and
is easily fixed; in fact, it
may be even hung in a
shaft from a chain ; it dis-
poses of its own exhaust
steam, it requires no special
attendant, and so long as it
is supplied with eteam it
will go on working. Under
these circumstanceB it is
evident that the puJso-
meter is capable of ren-
dering vei'y useful services
to the miner.
Water. — Some success-
ful applications of the
method of working pumps imderground by hydraulic power
transmitted from the surface have been carried out at mines in
Scotland and on the Comstock lode in Nevada.* A horizontal
engine erected at the surface (Fig. 554) works two rams d i£, and
these force water down the two pipes E E' to the underground
rams D D D' D' ; g g are valves through which water is supplied
to the preBSure-pipee from cisterns. The plungers of D D and
D' D' are attached to a cross-head C which carries the two pump-
ing plungers A and B. The ram d forces water into the two
power rams D, and the ram if into the two opposite rams D'.
If water is being driven down by d, the cross-head C will be
moved towards B; the mine-water will be forced up by its
• Joseph Mooro, "On Hj^dranUc Hacbinery for Deep Hlulng," Tram.
liM. Eng. aitd ShipfmMera in Scotland, vol. zxv., 1882, p. 177. R. T.
Uoore, " On an Improved ArraDeemeiit for Working UnderKronnd Pamps
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470 ORE AND STON&MINING.
plungOT, and sucked up by A. At the aame time the power
WBiter in D' ly will be oriTen back a little way, ready to move
in the opposite direction as soon as d' m&kee its stroke, ^e
nndei^round pump thus follows precisely the movement of the
engine at the suriMe ; the pressure in the tnoemittiDg pipes ia
not lees than looo lbs. per square inch, and this enables Btnall
pipes to be employed. The pumps may be placed as deeirad, and
the system has beisa used not only for permanent wotk, but also
in the case of sinking a shaft.
Compressed Air and Blaotrlolt7. — Pumps driven by com-
pressed air or electricity are very convenient in situations where
steam power is forbidden by the conditions of the wo^ings,
such as were set forth at length in a previous chapter, l^e-
■10-SS4.
^^^^5^5^^^^^^^^:^^^^:^^^^
pumps worked by electricity mostly take the form of three-
rams, driven from a common crank shaft, fixed upon the same
bed-plate as tlie motor. The high speed of the motor is reduced
by gearing, so as to give the crank shaft a number of revolu-
tions per minute suitable for pumping. The choice between
compraesed air or electricity will depend in many casee upon
what plant is in use at the mine for other purposes. If oom-
preesed air is being generated for boring machines or haulage,
it is only natural to make use of it instead of putting np a
special engine to drive a dynamo.
Where compressed air is laid on in a mine, it ia easy to employ ifc
for working a Knowlee, Cameron, Tangye, or other direct-acting
pump ; but water may be raised in a still simpler fashion \sf the
Fohl£ pump, which ia giving satisfaction at mines in Colorado,*
. and in supplying factories near New York. It is merely a pipe
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DRArNAGE.
471
Pio- 5S5-
full of water with a jet of air at the bottom. A B (Fig. 555) ia the
so-called well, a piece of ordinaiy wrDUght-iron pipe 3 icchee in
diameter ; it is connected hy a bend to the T-piece G, through the
bottom of which posaea a piece of J-inch pipe, bringing in air at
a jH^eBUre vuying from 30 to 70 Ibe. per square inch. The
water-column proper is made of
s-inch pipe, D £ F, which turns
over at the top and discharges
into another well Q. The height
from the bott<mi of C to the top
of the water in Q is 100 feet,
but as the level of the top of the
water in the well A B is 50 feet
above G, the actual lift eStoted
by the air is only 50 feet. By a
succession of sudi lifts the water
can be raised to any desired
height. This pump commends
itB^f by ite simfdicity, by the
eaM and cheapness' with which
it can be constructed, and by the
abeenoe of any expense for keep-
ing it in order.
For some time past Messrs.
EvauB and Veitoh have been
raisiiig water at Cae Coch Mine,
in Carnarvonshire, by the direct
action of compressed air. Their
latest pump (Figs. 556 and ss?)
conidste of two forcing chambon
A and A' Bubmerged in water,
each provided with an inlet valve,
B and B', and a discharge valve,
C and G', which lead into a com-
mon rising main D, ComprsBsed
air, brought into the two duun-
bers alternately by the pipes E
and E', presses upon the surface
of the water and forcea it up
tiie pipe F or F into D. The
compressed air is turned alternately into £ or E' by the action
of a valve worked by the independent cylinder O, placed in any
convenient aitnation, H (Fig, 557) is a pipe brii^png air from
the coinpreaaor to the valve-ohsst I, with its paton valve J. In
tbe position shown, E' ia receiving air by the port e", whilst E
communicatee with atmosphere through e. The valve J is moved
by the tappets K £*, which are struck by the croeahead L,
attached to therod which ia common to the two pistons Mand2T.
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47*
ORE AND STONE-MINING.
O u the piston-Talve admittmg oomprottiod air into the cylinder
a horn the pipe P ; it is worked by the tappets K' K*. The
cjlioder Q is fall of oil, which can be drawn txova one side to the
other by the piston
Fio. 556. N if the cock B is
open. The travd of
the }nston in N can
be regulated by the
cock ; the more nearly
it is dosed the slower
will the piston move.
In order to make
sore that the valve O
shall not stick partly
open, two sets <^
holes, a' s* a* <*, are
provided, and when
the piston passes, for
instuice, between ^
and ^, the oil can
make ito way round
without going
through the cock ;
the decreaee in the
reeistance quickens
the stroke and makes
it sharp and decisive
at the end.
With the object <rf
economising the com-
pressed air, the in-
ventors propose in
some cases to take
the exhaust from the
pipes E and E' direct
to the compressing
cylinder, allow it to
expand behind the
piston and so return
a little of the power
expended in compres-
sing it. The two
chambers A A! may
very well be joined together in one casting, as they are in the
pulsometer, and they may of course be far more deeply submerged
than is shown in the figure.
Duty. — In accounts of pumping engines the student will often
meet with the expreesion " duty." This term means the number
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DRAINAGE. 473
of poands of water raised i foot high by the consumption of 1 1 3
rounds of cwal; as used by Watt the quantity of ooal was i
ushel, reckoned at 94 pounds. In the early part of this century
much interest was evinced in Cornwall with reference to the
work done by the Tarious pumping engines of the county, and
there was great rivalry among the engineers, who vied with each
other in getting the highest duty from the engines and the
maohinery under their charge. The consequence of various im-
provements in engines and boilers resulted in reaching duties
which approached and even for short periods exceeded 1 00 millions.
The perfcomance of each engine was ascertained by attaching
a counter to the beam, which registered the number of it«
oscillations; the counter was kept under lock and key and
oxamined monthly by an independent observer. The number of
strokes made by the engine was thus known. The work done
in pumping was calculated from the number and depth of the
various lifts, the size of the plungers and the stroke of the
engine, and a record was kept of the amount of coal cousumed.
With these data the duty could be determined, and the figures
WK« published every mouth. Nowadays this spirit of emulation
among Cornish agents seems to have disappeared, few engines
are " reported," and the duties recorded do not as a rule exceed
50, 60, or 70 millions.
Though the knowledge of the duty is valuable in indicating the
general efQoienoy of the pumping plant, the mere determination
of this figure does not give aU the information that ought to be
in the hands of the mining engineer, for it does not tell him
where he can and should make improvemente. When he finds a
difference in the respective " duties " of two pumping engines at his
mine, there is nothing to tell him whether the fault of the less effec-
tive plant Uee in the coal, the engine, the boilers, the tTonSmitting
arrangements, or the pumps themselves. It is important, there-
fore, that the engines should be indicated, and that the indicated
hmrse-power of the engine should be compared with the actual
useful effect in water raised. Hammer * has found that the power
consumed in some cases by the mere friction of the guides in the
shaft is as much as 24 to 30 per cent, of the total power given out
by the engine. Too much importance cannot, therefore, be paid
to the accurate fixing of the main rod and its guides.
Slip. — In calculating the deUveiy of a plunger it is usual to
make an allowance for the running back of some of the water
through the valve, from its not closing completely when the
down-stroke commences. This is what is known as "slip," and
it is sometimes estimated at 30 per cent, of the actual delivery,
though in reality scarcely appreciable in the best pumps.t
Co-operative Fumping.^-Owing to the subdivision of pn>-
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474 ORE AND STOKE-inNXNO.
perty in this coimtty and want of appredation of the importance
of the sabject, too Uttle attention has been paid to what may be
called oo-cwerative drainage. One sucGeesfal application d the
principle, the Halkyn Tunnel, has been mentioned, and another
instance deeerree to be noticed, though in this case the mineral is
coal. Hie Sooth Staffordshire Hinee Drainage Commission is a
corporate body constituted under eevOTal Acts of Parliament,*
passed during the last twenty yean, for the purpoee of
facilitating the drainage of mines in parts of South Staffordshire
and Sast Worcestershire. The CommisBionera hare power under
their Acts to levy a rate of qd. for every ton of coal, slac± and
ironstorie raised within a oerlain district, and 3d. for every ton of
fireclay and limestone. In order to have some check upon the
statements of output made by the mine-owners, the Gommissionera
have by their last Act obtamed the right of phicing inspectors
to report upon the quantitiee of minerals raised.
It is not merely by erecting pumping engines of the most
approved and economical types at suitable centres that the
Oommiesioners have done good work; but the results of their
labours in preventing surface water from finding its way down
are well worth recording. To use th^ own words, " By carrying
out surface drainage works, such as rendering water-tight the
canals and streams throughout the district, draining large poods
of accumulated water on the surface, diverting or enlarging soch
watercourses as caused overflows in seasons of great rainfalls, and
such other works as were necessary to reduce the volume oi
water flowing into the mines by percolation to a minimum
amount," they reduced " the aveisge quantity of water which has
to be pumped in the Tipton district every 34 hours from
32,705,000 gallons in 1875 to 11,643,000 in 1883, a decrease of
nearly 50 per cent." When considering this remarkable and
very satisfactoiy result, the special circumstances of the district
must not be left out of sight. In no mining district in this
country are the effects of subsidence more apparent than they
are in places where the thick coal of South St^ordshire has been
worked uademeath, and therefore the cracked and fissured
overlying strata were ready to exaggerate the evils of percolation ;
but at the same time this very fact rendered the application of a
remedy all the more difficult.
According to the Annual Beport published in i893,t 27^
tons of water were raised for every ten of mineral extracted from
the mines, and at a cost, so far as the Commissionera' engines were
concerned, of o'lS of a penny, or less than one farthing, per ton
of water raised.
• 36 & 37 Vict., c. 150; 41 &4zTict., o. 81 ; 4S&46Tiot., c 131 ; 54 4
SSViot, c. 135.
+ (Mierg Ouardhn, vol. Izlv., 1S91, p. 648.
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( 475 )
CHAPTEB X.
VENTILATION.
Atmosphere of mines — Csases of pollatioD of the air in mines — Natural
ventilation — AiUflcial Tentilation bj f nmaces and b; mkchlnes—Fans
— Testing for fire-damp — Determination of carbonlo aoid and oxygen
— Auemometera — Water-gange — Efficiency olfans — Friction.
ATH08FHEBB OF HIITES.— The compoeition of the air
of the atmosphere is about one-fifth b; volume of oxygen and
four-fifths of nitrogen, with a little carbonic acid gas ; more
exactly, the Btandatd amount of oxygen may be taken at 30*9 per
cent., and that of the carbonic acid ^ls at O'o^ to 0*04 per
cent.
The atmosphere of mines is subject tu variauB influences which
are constantly rendering it leas fit for supporting life ; not only
do noxious gases escape from the rocks into the undei^round
excavations, but the very agents themselves employed in the
execution of the work pollute the air considerably.
Gasea sometimes given off in mines are : carbonic acid, marsh
gas, nitrogen, sulphuretted hydrogen, and the vapours of mercury
and volatOe hydro-carbons.
Carbonio Acid is known to exude from coal, and is also met
with in beds and veins of other minerals. It is common, for
instance, in the Sicilian sulphur mines,* where it is called by the
miners rinchiusu.
At the lead mines of Pontgibaud, in Central France, it is so
abundant that special fans have to be provided for getting rid of
it ; very distinct issues of this gas may be observed at the Foxdale
lead mines in the Isle of Man.f Emanations of this gas from
" lochs " or " vugs " have been reported to me as occurring at
Great Laxey mine, in the Isle of Man, and at Pennerly and
Koman Gravel mines in Shropshire ; however, in none of
these, as far as I am aware, has the issue been so strong or so
lasting as at Foxdale. In the Alston Moor district, according
to Mr. Wallace, the quantity of carbonic acid discharged both
* Baldaoci, Duerizione gtologiea dtS, 'liola di JSicilia, Rome, 18S6, p. 361.
t C. lie Neve Koster, " An Emanation of Carbonic Add at Foxdale Iline,
in the lale of Han," Traru. B. OtoL Soc. OormcaU, voL x., p. 175.
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476 OKE AND STONE-MINING.
by the vfODB and the encloBiDg rocks is oocasionally very con-
aid er&ble.*
Carbonic acid is thought hy Slountf to exist sometimee in
the liquid state in minute pores or fiaeuree of cholcopyrite, and
he ascribes the decrepitation of certain kinds of pyrites, when
heated, to its presence. No doubt such pyrites would be
capable of giving off the gas slowly at the ordinary temperatures
of mines.
The hot springs and their accompanying gases at Sulphur
Bank mine I in California ore very remarkable. An analysis
of the gas gave :
Carbon dioxide 89*34
Hjdrogen inlphide .... o'2i
Hiirah-gaa 7*94
Nitrogen 3-49
Some of the emanations contained ammonis, and the tempera-
ture of the water escaping from cracks in one of the levels was
176° F. (80° C), or more than the highest temperature ol»erved
at mines on the Comstock lode.
Marsb-g^ is the main constituent of fire-damp, which is by no
means confined to coal mines, as some might suppose. In this
country it is found in small quantities in the stratified ironstone
of the Cleveland district, and also in the Cheshire salt mines. As
minute bubbles of the gas may be noticed in the brine which is
pumped up from bore-holee near Middlesbrough, it is probaUe
that it aooompanies rock-salt in that region also. MUl Close
lead mine,§ in Derbyshire, was the scene of a disastrous ezploEi<m
of fire-damp, some years ago, by which five men were killed, and
in 1884 two men were biu^t by the gaa taking fire in a level at
Holway Consols Mine,|| near Holywell in Flintshire, where a fatal
accident had happened from an esplosion fifteen years previously.
At the famous Van Mine^ in Montgomeryshire, fire-damp was
found at the adit, and at nearly every level below, while " tapping "
the lode ; in other words, while nuddng the first drivages in it
The miners regard it as a sure harbinger of lead ore.
£ven the tin mines of Cornwall are not entirely free from fire-
damp. Inflammable gas was given off by the bed of stream-tin
* The Laiot ahich Segvlate the Dentition of Lead Ore tn Vtira, LoDdoo,
1861, p. 13a
+ "De<u«pttatloDB in Samples of ao-oalled Explosive Pjrite*," Jour. Chem.
Soc., vol. ilvii, 1885, p. 593 ; and Min. Jour. vol. Iv,, 1885, p. 1397.
X Becker, " Geology of the Qaickailver Depoaits of tbe Pacific Blope,"
Jtfon. V. 8. Geol. Survey, vol. xiii., WMliington, 1888, p. g-iZ.
% Eeporti of H.M. In^ectori af Minei for the Year 1887, p. 316,
II Ibid., 1884, p. 304.
H C. Lo Nexe 'Poater, " Notes on the Van Mine," Tram. £. Otol. Abe.
ComwaU, vol. x., p. 36.
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VENTILATION. 477
worked under tlie mud of Restrougaet Oreek,* near Falmouth, in
1873, and three comparatiTelyslight explosions took pl&ceat Tiixtg
Dong Mine,t near Penzance, about the year i860, on re-opening-
a level which had long been under water ; but in this caao, as in
some others which will be mentioned, the gas seems to have been
formed by the deoompoeition of the timber supports of the level.
Turning to the Oontiaent, it ia not surprising to meet with
large quantities of inOammable gas in oil-wells and in ozokerite
mines. The work of sinking oil-wells in Roumanian is much
impeded by emanations of marsh-gas ; artificial ventilation becomes
necessary when a depth of 50 feet (15 m.) is reached, and the first
thing the men have to do in the morning is to work the fan for
three hours. Even then the sinker cannot stay down more than
about two hours at a time, and when the bottom of the shaft is
approaching the oil-bearing stratum, he cannot stay more than a
quarter of an hour. He is aln^ye fastened to a rope, and two
men at the surface are constantly on the alert to draw him up at
onoe, if he makes the least sign hy pulling it. The sinker is
sometimes quite giddy when he reaches the surface.
The conditions at the petroleum wells of Burma are still more
unfayoumble. There ia so much gas that breathing is difficult,
and the longest time a young and strong man can stay below
without becoming unconscious is ago seconds. Often a man can
work only i or z minutes ; he can be lowered to a depth of 200
feet in J minute and raised in i to i^ minutes ; in the upper
parts of a well, where there is no gas or only a little, he can
remain below much longer.§
There are probably few, if any, mines m<n« fiery than the
ozokerite pits of Boryalaw. Explosions have often happened, and
the mines have to be worked with safety lamps. However, it ia
likely that both here, and in the oil regions, the inflammability of
the atmosphere is due not only to mafsh-gas, but also to
the vapour of volatile hydrocarbons given off by the crude
petroleum, which may be seen on the floor of the workings. Mere
marsh-gas alone would not account for the spirituous taste of
the air and the alight smarting of the eyes which are noticed
underground. The effect of the gase« is to produce all sorts of
hallucinations and make the men wander in their talk.
The sulphur rock of Sicily |1 emits fire-damp very frequently,
* Tavlor, " Description of the Tin Stream Works in Beetrongnet Creek,
near Traro," Proe. Iml. Metk. Eng., 1873, P. "S9-
t UiggB, " Notice of an Acaamalation of Carbnretted HTdrogen, or
■ Fire-damp,' in the Ding Dong Mine," Tram. R. OtoL Soe. Oornmdl, toL iz,,
t Ejrpotition Univtridie dt Pmi* en 1889 : A'oliee mr la Boumatue, Paris,
1889, p. 60.
§ NoetUag, " OU-fleld of TwingouDg and Berne, Borma," See. OeoL
Slavey India, vol. udi., 18S9, p. 98.
II Beldaoci. op- <^-i P- 3^3.
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47S OBE Ain> STONB-MINDfO.
and the officul list of disBsboDs ezplocoMts shows that it is an
enemj not to be despised by the miner. Tita gas fills cavititti
ezisting in the bed of mineral, and also oomee oat of the
bitominoos shale of the partings ; it is called antimumio by the
men.
Harsh-gas aooompttnies salt on the Contineot, as it does in
EngUnd; a jet of the gas, which has been [aped off from a Uow^
and DOW eerree t<« iUaminating porpoees, maj be seen constantlj
boming in the salt mine at Bex in Switxerlmd. Small explo-
sioDS have taken place in the StaasfDit distxict.
Several men were killed by an ezploeiixi of fire-damp in a
tnnnd in the Oxford Clay * which was in coarse of being drivaa
under the Col de Cabres, on the bonndary of the Deparlanents
Drome and Isire in France, during tbe year 1S87, and iha gas is
given off in such qosntities in theday pteat KJmgenberg on the
Uain t that safety lamps have to be used by the miners.
Inflammable gas is not nolaoed in wooing the cof^ter efaftle
itself at Hansfeld, though the large amoontof bitominoos matter
whidi the seam contains mi^t make cme fear it would be troaUe-
some; a little has been met with in driving levels in scane of the
snrronndiDg rocks and espedaUy io tbe gypeom.
iMem quantities have been observed in Silver Islet mine,!
lAke Saperior, where sever^ explosions occurred ; and at Duncan
mine,§ Rirt Arthur, upon the same lake, vugs were noticed to
contain hydrocarbon gas under great preesare-
Becker records emiesiona of inflammable gas at several of the
qnickslver mines in Galifcvnia. {[ Inflammable gas, probably
manh-gas, caused a diaastrous explosion at the Bell tunnel of the
New Idria Mine, and marah-gas escapes at the ^tna Mine. At
the FbfBuix Mine inflammable gas issues from cracks in l^e 150
and 200-foot levels, the chief component being marsh-gas, as
shown by tbe following analysis :
Carbonic anbjdride .... 074
Hanh-gas 61-49
Nitrogen 31-^^
Oxygen 633
Treloar % gives an account of an issue of inflammable gas at the
Motto Velho gold mine in Brazil ; it took Are while the men were
boring a hole.
* Cbtmtet Sendia, Soc. Jtui. Min., August 1887.
+ CoBitry Ouardian, »oL Iri, 1888, p. 192.
t Macfu-lsne, "Silver Islet," Tram. Amor. Intl. M.E., voL viii, iSSo,
p. Z41 ; £1147. ilin. Jour., *oL zxxiT., 18S2, p. 32a.
I Tram. Aiaer. InMt. M.E., ToL xv., 1887, p. 673.
" " Geology of the QnlckBllver Depoaits of the Pacific Slope," Mon. V. S.
QerA. Survey, WoshinetoD. 1888, pp. 30S and 373.
f Trant. R. QeoL Soe. Comwaa, Tol. vii. p. 345.
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VENTILATION. 479
Fire-damp is frequently encountered in the old workings of
alluvial mines in the goldfielda of Yictoria ; * in some instances it
is doubUess due to the decomposition of prop timber, as at Ding
Dong, and in others to the gradual alteration of driftwood or
organic matter in the alluvial beds themselves. A eerioufi accident,
caused by a fire-damp explosion, is recorded as having injured two
men at the Try-again Company's mine, £1 Dorado, in the Beech-
worth Mining district. t
TTitrogen, if given off in small quantitiee, is likely to pass un-
noticed by the miner ; but it makes its presence felt occaaionally.
Miners in Strinesdale tunnel, near Stockport, have been troubled
by the escape of nitrogen from fissures in the rook. It has been
ascertained by analysis that the gas consists of 92 volumes of
nitrogen, S volumes of oxygen, and a trace of carbonic acid. It
came from openings in the roof, sides and floor, and was strong
enough, in one case, to put out a candle t8 inches away from the
fissure. The men became sick and dizzy, and their limbs were
semi-paralysed. On some occasions the fissures drew the candle-
flame in, instead of blowing gas out, suggesting a communication
with old workings in the neighbourhood.
The highly poisonous snlphiuetted hydrogen is of frequent
occurrence in the Sicilian sulphur mines, where the water is
often saturated with it. At the 3000-foot level of the Oom-
stock} lode, the water is charged with carbonic add and
sulphuretted hydrogen, and has a temperature of 170°?.
(76*7° C). A blower of the gas, met with in a copper mine at
Ducktown,§ Tennessee, was strong enough to drive the men away
from their work for a time. Two bad accidents took place in sink-
ing a shaft at Stassfurt, through rock-salt, from sudden irruptions
of the gas : on one occasion eight persons, and on the other seven
persons, were stifled. Yarious fatalities are asciibed to sul-
phuretted hydrogen at the ozokerite mines of Boryslaw, but here
it is thought that the gas was generated by some process of de-
composition in old workings, which were " holed into " by the
miners. Sulphuretted hydrogen produced in a somewhat sioiilsT
way is supposed to have been the cause of a death at a mine on
the Gympie goldfield, Queensland.!!
As a natural emanation in mines, solphaioilB aoid is very
rare, but Becker has noticed a pungent gas near the 150-foot
level at the Bedington quicksilver mine in California, which
he considers must contain both it and sulphuretted hydrogen.^
1885,1
t Becker, op. et(.,p.339.
% Phillips, Ore Dtponit, 1S84, Loodon, p. 574.
H Fi7ar, Otua in, Minei, Briabane, 1890, p. 8.
H Op. eU., p. aS?.
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48o ORE AND STONE-MINING.
Sulphurous add is senented in the undei^Tonnd fires of sulphur
mines in Sicily, ana some will be formed in other caaea of imder-
grouod fires, if the rock cantains iron pyribeB.
Sm&ll quantitiee of merouiial TApour are stated to be found in
quicksilver minee, and to be the reason of their unheal thin eea ; but
one may also suggest that constant contact with cinnabar, inhaling
the duet of the mineral, and allowing some to enter the atoiiiBc£
from eating with dirty hands, may possibly account for all the
aymptoms observed, without haviiig recourse to the theory that
the vapour is present in the atmosphere of the mine.
Artlfloial Follutloii of the Air in SCinee.— The pollution
of the air is not due solely to gasee introduced natuxally irom
the surrounding rocks ; various other causea combine to render
the atmosphere of the mine unfit for life, and among them may
be mentioned the following :
1. Rei{diatioii of the personi and anlmalB in the pit ; ezhalationa from
their hUh, and emanations Crom excrement laTt nndergroiuid.
2. Comtmstlon of the lamps and eaudloa uied for llgfatiag the workiiig
1,3. Dr. Angus Smith* reckons that two men working mght
hours, and using ^ lb. of candlesand i a ozs. of gunpowder, produce
35-393 cubic feet of carbonic acid at 70* F. — via,, io'32 by
breathing, i3'z76 by candles, and 3-796 by gunpowder.
It is considered by some medical authorities that the injurious
effects of breathing an atmosphere polluted by the products
of respiration, are due more to organic matter than to the
small proportion of carbonic acid it contains. The quantity
of carbonic acid serves, however, as an index of the amount c^
organic pollution, and when the air of a room is found to contain
0-0^ per cent, by volume of the gas, the atmosphere is said to be
unhealthy. Care should be taken to prevent the men from
habitually using the workings as latrines, and to apply suitaUe
disinfectants if the rule has been disobeyed.
3. Where the ventilation is sluggish, the abeorption of oxygen
by pyrites, or by ferruginous minerals passing to a higher state of
oxidation, is sometimes very marked.
4. More important is the foulness of the underground atmo-
sphere produced by the decay of the timber supporte. The nipidity
irith which timber rots underground in certain circiunstances
has already been mentioned ; the practice of leaving the useless
decaying timber to infect the new pieces that are put in, turns a
■ Sepcai of the Commiitionen appointed la in^ire tnfo Hit Ooitdititm of
a& Mittei in Ortat Britain to trhich the Frouinoni of the Act 33 iC 34 Fi'ct.
c. IJI do not appty, Appendix B., LondoE, 18&4, p. 334.
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VENTILATION 481
level in some instances into a hotbed of putrescent matter, offensive
to the BmeU, and injurious to the health of the men. 8t«6l
Bupports ahould be welcomed, if only for ridding mines of one
source of pollation of the atmosphere. One of the recommenda-
tions of the Ventilation Board in Victoria is that all the bark
should be removed from the timber before it is sent down mider-
ground.*
5. The nature of the gases and solid residues produced in
blasting has been already explained in Chapter IV,, and the
statement made by some manufacturers that their explosives
produce " no noxious f umea " is evidently misleading. In the
case of gunpowder, we have the smoke made up of fine particles of
carbonate and sulphide of potassium with some sulphur, whilst
the explosive force has been due to the formation c^ a number
of invisible gases, especially carbonic acid, carbonic oxide and
nitrogen, with sulphuretted hydrogen, marsh-gas and hydrogen.
Nitro-cotton should produce nothing by its explosion but
carbonic acid, carbonic oxide, hydrogen and nitrogen ; and nitro-
glycerine only carbonic acid, nitrogen, and oxygen. But when
imperfectly detonated the reeult&nt gases are more noxious ; both
explosives generate a large proportion of nitric oxide, and carbonic
oxide is liberated in considerable quantity. Dynamite produces
the same gases as nitro-glycerine, but, in addition, it sends into
the atmosphere, in a very finely divided state, the 25 per cent,
of infusorial earth which it contains, Tooite, mode from gan-
cotton and nitrate of barium, produces solid carbonate of
barinm, and the qnantity is estimated to be 55 per cent, of
its weight.t
Hore has been written of late years about the fumes of roburite
than about those of any other explo^ve, and many useful observa-
tions have be^i made concerning it. After a dose examination and
an analysis of the fumes produced by tonite and robuiite. Prof.
BedsoQ and two medical menj have come to the conclusion that
these two explosives are no worse for the health of the miner
than gnnpowder. With all three explosives they found traces of
carbonic oxide in the air, and they recommend in consequence
that an interval of five minutes be allowed to elapse before the
men return to their working places after firing. The ore-miner,
in studying these conclusions, must not forget that the recommend-
ation is made in the case of working-places which were being swept
out by air-cnrrents of iioo to 5000 cabic feet per mmute —
in other words, the moral is, that if no such currents exist, a
longer interval should be given. No nitrobenzene was detected
* S^ort of the Vtnlilalioa n/Minu Board, Uelboome, 1888, p. z.
f " An InToMlgatloD aa to whelhei the Fames prodaced from the Use of
Robnilte and Tooite in Coal UineH are injnrlons to HealtJi," Train. Fed.
JmI. Min. Eng., vol. 11., 1891, p. 380.
t Bndtm, p. 388.
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48i OEB AUD STONE-MINING.
in uulyung the air after firing roburite, tfaough its odour ma
noticed on some occaaioDs.
6. We now, lastly, oome to stone dust, which ia oertainl; not
the least noxious d the impurities of the atmosphere breathed
by the miner. It is formed in the process of boring hcdos for
blasting, by the ehote themselves and hy the attrition of piecee
of rock tumbling about during the ordinary proceeaes of mining.
However, it is probable that the first caoee is the one from which
the miner is moBt likely to suffer injury : when he is boring a hole
downwards he puts in water, which serres the douUe purpose of
fociliteting his work and of preventing any dust from being
formed ; but when he bores an " upper " by hand, water is not
nsed, And even where machine drills are employed, it is not always
that one sees a jet of water under pressure applied to the bore-
hole. The result is that the atmosphere of an "end " or other
working place may contain a quantity of fine partiiJee of stone
in suspension, which are inhaled into the lungs, and irritate
the air-passsges ; very probably they are the principal cause of
the complaint known as " miner's asthma " or " miner's con-
Having pointed out the manner in which the atmosphere ot
mines is constantly being deteriorated, it is necessary to explain
how it can be renewed, and so kept in a fit state for the workmen
employed underground.
NATUBAIi TSKTIZiATIOn. — Two systems of ventilation
are employed in mines — natural and artificial, either separately
or combined. Under the former, currents set up by natural
diSerences of temperature change the air of the workings ; under
the latter, artificial means are employed to bring about the same
result.
The principle upon which natural ventilation depends is very
eafflly understood. The temperature of the earth increases at the
rate of i" F. for about every 60 feet of depth, and this natoral
heat is the mainspring in creating air-currents. Suppose a very
simple case, two shafts AB, CD (Fig. 558), connected by a
horizontal level B D. The air in the shafts and level, warmed by
its contact with the sides of these undeif;round passages, gradually
assumes their temperature, which will be usually higher or lower
than that of the external atmosphere ; the problem is simply
that of two communicating vases. At the pomt D we have the
pressure doe to the weight of the column of air CD + the weight
of the atmosphere at C. At B the pressure is due to the weight
of the smaller column AB + the weight of the atmosphere at A.
Draw the horizontal lines CF and AE and prolcmg the line of
the shaft AB upwards by the dotted lines. The pressure of
the atmosphere at F and 0 is the same, and therefore any
difference of pressure at B and D depends upon the relative
weights of the columns FB and CD ; but AB is equal to £D, so
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VENTILATION. 483
that the real difference depends upon the weights of the two columns
of air FA outside the mine and CE inside the mine. In this
country the external atmosphere in summer is often hotter than
that of the mine ; therefore the column CE will be heavier than
the column FA. The column CD will overcome the resistance
presented to it by the column AB, and create a natural current
going in tbe direction CDBA. In winter the conditions are
Pio. 558.
Fio. 55<).
¥10. 560.
reversed. The cold external column FA is heavier than the
comparatively warm internal column CE, and the weight of the
entire column FB will be greater than that of the column CD.
Tbe result is that the weight of the column FB will cause motion
in the direction ABDO,
A still simpler case is one of common occurrence in vein mining
(Fig. 559). Let AB be bjq adit driven into a bill-side. Draw
CD horizontal, and by tbe dotted lines AD indicate a column
of air. The pressure of the atmosphere at C and D is the same ;
the pressure at A is that of the column of air AD + the weight
of the atmosphere above the line CD,
whereas at B one hss the same constant
weight above the line DC together with '
the column CB, If AD is warmer than
EC, there will be a greater preesore at
B than at A, and the current will move
in tbe direction CBA ; if AD is colder
than BC, a condition of things happen-
ing in winter, the current moves in pre-
cisely the oppcsite way.
Another state of things is shown in
Fig. 560, in which there are two shafts
of unequal depth connected by an in-
clined passage or drift. If AE is
drawn horizontal, as before, at the level of the higher opening to
the mine, and CF parallel to it at the level of the lower opening,
the air in the bent tube, so to say, CDB, will exactly balance
that contained in the vertical shaft FB, and for motive power we
have to depend upon the difference in weight of tbe two columns
AF and EC, a diffm^nce depending upon their relative tempera-
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484 OEB AND STONB-MINING.
turea. Therefore in smnmer we get a current travelliDg in the
direction ABDC, whilst in winter it is reversed.
Id aoj one of these cases, the greater the difference in tempera-
ture, the greater will be the velocity of the ventilsting current. In
winter the ventilation will be more active than in summer, because
there will be more difference between the outside and inside tem-
peratures; and, furthermore, though there are dLBerenoee between
the day temperature and the night temperature, still the tenden^
is always to produce a current In the same direction. In summer
the nights may be cold though the days are hot, and therefore
the difference in temperature between the air of the mine and
that of the surface may be acting in two opposite ways according
to the period of the day or night, A abaft which is drawing up,
or is an " upcast," during the heat of the day may have a
deecending current, or be a " downcast," in the cool hours of the
night, and practically have no current at all while the outside and
inside temperatures are alike.
There is not only this objection to natural ventilation that it
may vat; in direction during the course of the twenty-four hours,
but the still greater objection that at certain seasons of the year
it may be nil, because there is no difference in tempetB.tnre
between the outside and inside air to make one column heavier
than the other.
The creation of a natural air-current is not due solely to the
difference of temperature caused by the natural warmth of the
rocks. The heat engendered by the respiration of the men and
animals, by the combustion of the candles or lamps, and, lastly,
by the exploeivea is also a factor in making the air of the mine
warmer tnan that of the surface and so setting up a current.
The character of the sides of the shaft itself may aJao play its part.
A shaft which has water dropping down it, either from natural
springs that find their way in, or from alight leaks in the pumping
plant, will naturally become the downcast, if the other orifice is dry.
The strength of the current may be improved, or a natnral
draught created where none existed before, by building a chimney
above one of the shafts, and so producing artificially a difference c»
level between the two outlets. The direction of the wind may also
turn the scale, and it is often found that a mine is better ventol&ted
with Bome prevailing winds than with others. As an illustration
of an effect of this kind, I need only refer to smoky chimneys,
commonly cansed by the wind striking some natural or artificjal
obstruction, which directs it downwards and makes it overcome
the upward draught of the fire. The result is sometimes so
marked that the householder can tell the direction of the wind,
before looking out of doors, by noticing which of his chimneys
is giving trouble. With some mines in which the natural current
has less force than that of a chimney, it is not to be wondered
that similar ooourrences take place.
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VENTILATION. 485
When speaking of natural ventilation, the property of diffusion
requires a votd of comment. This property is one by which two
bodies of gas placed in juxtaposition with one another gradually
become mixed, even if the liehter occupies the higher position.
The process is slow compared with the mixing that is brought
about by convection, but still it has some effect in causing the dis-
persion of noxious fumes.
In the examples of natural ventilation just given, it has been
assumed that the mine has two orifices ; but many workings, at
all events at the beginning, have only one. IiOt us teke the three
typical cases of a level, a shaft, and a " rise."
Let Fig. 561 represent a level driven a short way into the
FiH, 561,
3
side of a hill. How is the atmosphere of the " end " renewed
without artificial appliances { On entering such a level after
blasting, the explanation becomes apparent : a current of powder
smoke is seen hugging the roof, whilst the lower half of the level
is clear. If a candle is set up on the floor, its flame is deflected
inwards or towards the " end." The heated gases from the ex-
plosive, accompanied by air warmed by breathing and the combus-
tioa of the candles, rise as much as they can, and make their way
.outbytheupperpartof the level, while their place is taken by cold
air from the outside. The course of the gentle current is shown
by the dotted lines. The same phenomeuon may be observed in
Via. s6i.
a cross cut driven out from a shaft. This explains tite import-
ance, or indeed the necessity, of keeping a level as horixontol as
possible if it is being ventilated naturally. Take an exaggerated
case, in which the men have allowed their " end " to rise consider-
ably, as shown in Fig. 562, so that the floor of the working plane
is three feet above a horizontal hne drawn through the top of the
mouth of the tunnel. Smoke and warm gases produced in the
" end " will rise, and, finding no means of exit, will remain in the
highest part until they cool down and diffusion has had time to
play its part.
It might seem at first sight that a current could not be formed
in a shaft which does not ccoumunicate with other workings ; but
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486 ORE AND STON^MINXNO.
ev«n wheu no partition of any kind tuts been put in, the sides
of the pit kept oool hy trickling water may cause the air to form
desceDding currents, whilst in the centre there is an aecending
canrent, as shown in the diagram (Fig. 563)' In an iodine
(Fig. 564) the ascent of the warm smoke along the dry roof
and the influx of Cold air along the Sixxr are sometimefi vei;
noticsable.
Whan the working place is a "nse," it is evident theoretically,
and stilt plainer practically, that the warmth of the fool gases at
the top tends to keep them in that poeitioD, and that the evil
must increase as the place gets hotter (Fig. 565). The nature rf
the excavation prevents things from improving, and the necessity
for artificial ventilation is nowhere more apparent than in a
working place of this kind, especially if the space is confined.
The common statement that carbonic acid collects in the lowest
part of the workings is correct only in cases where the gas is
1110.563.
Fio. 564.
Fio. 565.
issoing forth from the rocks and sinks down like water. Where
it is produced by respiration, caudles, lamps, or explosives, it is
di£l\ised through a warmed atmosphere, ascends with it and does
not separate from the other gases. The ccmseqnenoe is that a
"rise may be found badly ventilated although the air in the
level below is fresh and pure.
We will suppose that by reason of the difference in level of the
two main orifioes of the mine, a trunk ventilating current Jhaa
been established. The air will then take the easiest road from
one shaft to the other, aud will not penetrate into any other parts
of the workings unless compelled to do so. The taming of the
current into any required direction is effected by putting in
partitions and doors. In a fen cases, the partition serves to make
a clean and sharp hne of division between two currents which
would to a certain extent exist naturally. Thus, we have seen
that when the length of a level is not great, an outward current
travels along its roof, and an inward current along its floor (Fig.
56 1 ^ ; between the two there is a dead space more or less interfering
with both currents by making their boundaries iU-defined. If a
horisontal partition of planks (air-BoUar) is pot in (Figs. 566 and
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VENTILATION.
487
567), the two cnrreDte are kept perfectly distinct, and the
oatnial ventilation, aided in tliis way, proceeds in a mnoh more
effective manner; the level can therefore be driven further
without having recourse to machinory for creating an artificial
curraDt.
A. common problem is the ventilation of the far end of a drivage,
AB (Fig. 568), provided with a little shaft, CD, which, in
winter, naturally creates a current proceeding from A to D,
and ascending at once to C. The denred effect may be attained
by putting in an air-sollar DE, which compels the air to travel
. oorering the bottom of the shaft by a platfi
(aoBar), and carrying a pipe from it all the way along the roof
of the level to the " end." This has, of course, the same effect
as the air-sollar, but, unless the pipe is large, it does not give
Tin. $66. Fio. 567.
TD»
so much area for the current. Pipes have the advantage that
they are veiy ea^y put in and that they can be used again and
again. These methods of conducting an air current are so
s^f-ovident, that I should not have mentioned them, were it
not for the fact that some mine agents appear to be ignorant of
these rimple expedients for improving the v^itilation of their
drivages.
Where the level is wide enough, the partition may he placed
vertically; it is then called a f/ratlice. If required for temporary
purposes it may be made of canvas, tarred to prevent its rotting
{bratliet doth). More lasting and efiective partitions are con-
strocted of plank or of brick.
Any close vertical partition in a shaft dividing it into two
separate compartments invariably improves matters, when the
ventilation of a sinking is becoming sluggish ; some trifling differ-
ence in the condition of the two compartments decides which is to
be the upcast and which the downcast. Where it is not con-
venient to put in a partition, a separate air compartment may
be formed by fi'"'"g a lai^e pipe against one side of the shaft
and taking it up 30 or 40 feet above the level of the ground
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488 OBE AKD ST017E.HININa
(Fig. 569); in this maoner two columns of uaequal bedght are
produced with the desired efi^ct.
If a rise ie being put up, or if sloping ia being carried cb
without any winze, there is no diificulty in diverting a natmnl
current ezisting in the level below and maln'ng it serve the work-
ing place. All that is required is to block the passage of the
current along the level, and eo force it to take the only road that
lies open to it. In Fig. 570, AB is a level, end C the top of a rise,
which has an open compartment at each end ; one is fitted with
ladders, and the other serves as a shoot, down which ore or
rubbish can be thrown into the level below. They are separated by
the thick partition of rubbish piled upon a platform in the roof of
the level and confined by timber at both emda. By putting a
Fia. 569.
1
r-°
partition in the level, the air is made to pass up one end of the rise,
sweep out the foul air produced by the men, candlee and explosives
at G, and then descend into the level once more. The partition
may be a wooden door closing tightiy against its frame, or a
piece of brattice cloth hung from the roof, which is readily
lifted when a tram waggon has to pass underneath. In the case
of stopen the mode of procedure is identical, but the air current
has not to make nuch sharp tiimB.
The case represented in Fig. 568 is that of workings at one level.
In vein mining the ore is generally being excavated, or at aU
events preliminary drivages are being made, at more than one
horizon. In Fig. 571 two shafts have been sunk, and two
drivages have been made, one below the other. It is easy to
understand that at an earlier stage of the working, before the
shafts had been sunk to E and F, and the level BF driven.
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VENTILATION.
489
ft-
Ib 9 [a
a cutreut was set up from A lo C vid B and D, or from
C to A, according to the aeasoa of the rear ; but when the level
EF has been driven, wbat is to bring uie current down to £, for
instance, when it has the shixter and easier road direct from B to
D ? It often happens
that special condi- Fio. 571.
tions in the shaftA
themselvee, to vhich
allusion has already
been made, would in
any case causo a
movement in the air
from B to E, F and
D, even if the two
4X>lumns of different
height did not exist
above them, and in
that case some air
would find ite way
down to E and F; but by putting a door at G, somewhere
between B and D, the main current can be forced to proceed by
the longer road and ventilate the lower workings. If air is
required for men working in the level BD, the partition, or
door G, is not made close ; then part of the main current takes
the shorter road from B to D, and part the longer road from
B to E, F and D.
Owing to the number of shafts which are usually sunk in
working veins, and differences in the level of their mouths, natural
currents are set up to a much greater extent than is the case in
working beds, where a
Fio. 573. couple of pitH situated
close to one another and
at the same level have to
serve as the sole inlet
and outlet orifices. For
this reason natural ven-
tilation is often found
to provide a fairly suffi-
cient supply of air along
the main course of the
current, and the miner
has merely to provide for the ventilation of workings in the form
of a cul-ae-aac, such as ends, rises, and winzes, which are at a
distance from this current.
A common method of procedure is to sink winzes at frequent
intervals ; if AB and CD (Fig. 572) represent two levels, 10 to 15
fathoms apart, which are ming driven from A to B and O to D
respectively, we wilt suppoeethat a ventilating current existe as
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490 ORE ASD BTONE-MINING.
Bhown b; the urovrs. B and D ue blind Mejs, bo to eay, but
BO long OS their ends B and D are not far from the main drought,
the^ may be sufficiently ventilated by coavection cnrrenta, set
up in the manner explained in Fig. 561. Boon, however, this
imide of supplying air becomes inadequate, and the minei- estab-
liahes another communication between the two levels by a fresh
winse or rise JK; the ourrent is made to take the roiid shown
by the dotted arrow, if a stoppinK of some kind is put into the
winze FB. The name "winie, Bometimee written "winds,"
suggests that the original purpose of the intermediate shaft was to
furnish air. In some mines winzes are Bunk at fairly r^ular
intervals of 30 fathoms; of course, in selecting a place for a
winze, [weference is given to ore-bearing parts of the vein, because
the cost of sinking will then be partly or wholly repaid by the
mineral excavated. Even when the indications at the top may not
warrant the asBumpticoi that ore is present in paying quantities,
the winze serves to prove the ground and sometimes to reveal
unsuspected sources c^ profit. Winzes may be said, then, to have
five useful purposes : ventilation, exploration, starting-pcants for
stoping, shoots for ore or nibbish, ladder-roada for the miners.
I have thought it advisable to devote more space to natural
ventilation than the coal-miner would think it deserves, because
it is the method by which the trunk ventilation of most vein-
mines is cairied on at the present day, and has been carried on
for centuries. Nevertheless, I am fully alive to its two weak
pcunts— viz., want of constancy and want of strength. The minor
IS therefore often driven to seek artificial aid in order to make
up for these defects.
ABTIFICIAI. VmrTHiATIOlT.— Artificial ventilation is
produced either by (I.) furnaces, or (II.) machines.
i. TTTBITACB YINTHiATIOir. — By employing a fumaoe,
the miner can eflTect an artificial difference of temperature between
two columns of air in the mine, and so produce a current similar
to the natural draughts just described.
In small undertakings a fire lit at or near the bottom of the
upcast shaft, or contained in an iron vessel suspended in the pit,
suffices to create a current, when the natural ventilation is no
longer adequate, owing to the state of the external atmosphere.
From small bt^inninga of this kind has developed the large
underground furnace, which is, however, in the vast majority of
cases, confined to the domain of the coal-miner, and even there is
being gradually replaced by fans. My desoription may, therefore,
be extremely brief. The ventilating furnace (Figs. 573, 574,
57S)' is a huge fireplace at or near the bottom of the upcast s£aft,
over which is led either all the air of the mine, or a part of it.
The air heated in this way is rendered specifically lighter, and the
* CalloD, Zitetum on Mining, vol. fi., plate IzzzvL
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TENTILATION.
491
weight of the column of cold air in the downcast shaft overcomes
that of the air in the upcast and causes it to ascend. It is pre-
cisely the same action as that which takes place with the usual
domestic fireplace in this country, the chimney playing the same
part as the upcast shaft. Cold air is drawn in from crevices
Around the doors and windows, is heated by the fire, and ascends
the chimney.
If the air of the workings is charged with a dangerous proportion
of mflammable gas, it is led into the upcast ^aft by a speml
dnfb — the dumb drift — at a point where there is no danger of its
Fio. 573.
taking fire. In this case the air in the shaft becomes warmed in
its upward passage, not only from mixing with the current coming
from the furnace, but also by absorbing caloric from the heated
sides of the pit.
II. HBCHAiriGAJi VEHTII.ATIOn.~The methods of
mechanical ventilation may be classified as follows :
(I) Water blast.
(a) Steam jet.
((i) BecipTocatlng.
fa. Aotlng br diBplacemeiit.
(ii) Botary. J .^, , ,
|o. „ ,, oentrifngal foToe.
(i) The ordinary water blast is a very simple appliance : it is
the well-known tromp, used in some countries for blowing smiths'
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49a ORE AND STONE-MINING.
forges. A stream of water falls down a pipe, entangling air
drawn in hj lateral holes, and drops into a box or barrel with two
orifices i thdBO are so arranged that the air shall escape by ooe,
under a slight pressure, and the water from the other. The current
of air is carried by square pipes made of boards, or, better, by
cylindrical pipes made of sheet zinc, to the place where ventilation
is required.
The fall of water is also applied by Williama's water-jet
apparatus (Fig. 576). The waWr brought down in a pipe
from a reservoir, or fnun the
FiQ. 576. rising main of the column of
pumps, issues in the form of a
jet from a nozzle, and, driving
out the air in front of it, draws
in air behind. The water is let
off by a box with a discbar^
designed, like that of the tromp,
to give a little pressura, whilst
the air-current proceeds through a series of pipes to the *' end "
or other working-place. The water-blast has the merit of sapply-
ing a stream of cool moist air which is very acceptable whera
the working-place is diy and dusty. By reversing the apparatus
the current may be made to flow in the opposite direction, and
the " end " is then ventilated by having its foul air drawn out
and replaced by an inward draught along the level, instead oS
being supplied directly with fre^ air From the outside or fnxn
the main ventilating current.
(3) A ateam jet may be applied, like a jet of water, to create
an exhaust and to draw out the foul air. Por instance, we will
suppose that during the sinking of a shaft the air-pipe in Fig. 569
falls to act in an adequate manner, owing to a change in the
atmospheric conditions. The agent desires to remedy this state
of a£^rs by some cheap and temporary expedient. If he lyings
a pipe from the boUer of the winding engine to the upright
ventilating pipe, and provides it with a nozzle pointing upwards,
he can speedily and at small expense produce an upward
current by turning on steam. The steam jet drives air in front
of it up the pipe, and at the same time warms it slightly. The
exhausting effect produced in this way at the bottom of l^e pipe
is sufficient, in small sinkings, to draw out all the foul air.
A draught may be produced in an upcast shaft by a ring at
the bottom, from which issue a number of jets of steam. Such a
mode of ventilation may be useful in cases of emergency.
(3) Air Pumps. — Mechanical ventilation on a large scale is
always effected by some kind of air pump, and generally by one
which has a rotaiy action.
(i) Among the pumps which have a reciprocating action, the
ordinary air compressor must be named first, as its utility
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VENTILATION. 493
as a ventflating agent is great. The air escaping from boring
or other machines Tenders good service in driving out foul
fjases generated in the workii^ and there is the advantage that,
after blaGting, a powerful stream of air can be turned on for a
abort time so as to sweep out the noziouB fumes compietely.
Even where the ground is soft and no machine drill required, it
is ea^ to bring in air from the main by a line of smaller pipes,
and turn on a fresh current when needed. In one aeose it is
very uneconomical to bring air to a pressure of 60 or 7olb8.
to the square inch for ventilating purposes only ; but where
compressing machinery is always at hand for working underground
engines, it is better to be a little wasteful of a cheap power
at the surface than to .go to the greater expense of having a "ixiy
or a man to work a fan.
In a long level driven by boring machinery, with its " end "
far removed from the main ventilating cnrrent, the smoke
produced by blasting, though driven away from the actual
working face, still hangs about for a time, and pollnt«e the
atmosphere which the miner has to breathe in going backwards
and forwards. In such cases it is best to diaw away the foul
gases as soon as they have been produced, and prevent their
mixing with the air of the level With compreesed air at
his command, the miner can
easily work an aspirator of Tia. 577.
some kind, such as KOrting's,
or the somewhat similar con-
trivance of Mr, Teague (Fig.
577). The ordinary air-main
for bringing in the compressed
air working the boring ma-
chinery is shown at the bottom
of the level, with the [aece of flexible hose at the end. The
boring machine has been removed and the air shut off from the
hose ; by turning another cock, it passes up the- upright piece
of pipe and rushes out of the nozzle in a direction opposed
to tbkt of the drivage. This has a powerful exhausting effect,
and the " end " can be cleared of smoke in a few minutes.
The Hartz blower {^uot maeMne, Cornwall) (Figs. 578 and 579)
is an air pomp of simple construction which can be made up by
any mine cBipenter. It consists of two round or rectangulaj*
hoxea, one fitting inside the other, and moved up and down by
being connected to the main rod of the pnmps ; the upper box
has a valve at the top, and the lower box is provided with a pipe
also having its valve. The lower box is partly filled with water
so as to make an airtight connection. "With the valves ansziged
as shown in I'ig. 579, the machine will act as an exhausting
pomp and draw out Uie foul air; if the play of the valves i»
reversed it acts as a Idower.
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494 OBE AND STONE-MINLNQ.
StruT^'s ventilator ie a. ^gtaitic doubl&acting nuchine of thif!
«laas, BO constructed th&t it drawB air from the mine daring th«
down stroke as well as during the up stroke.
(ii) a. Among the njtar^air pumps acting by displacement may
be mentioned Boots's ventilator, of which various sizes are made,
suitable to the requirements of the whole of a large mine or
merely to those of a mngle "end."
This air machine (Fig. 580) consists essentially of two similar
pistons upon parallel shafts, revolving in a casing, but without
actually touching each other or the casing. The clearance in a
large ventilator is under j\ inch, l^e pistons are of such a shape
Fig. 578. Fio. 579. Fio. 580.
that a definite volume of air is d»wn in or forced oat by each
half -re volution. As the pistons are always kept in position by
gearing, there is no fear of one coming in contact with the
other.
(ii) b. Centttfogal Tentilators or Fans.— This dass includes
all the most important ventilators in use at the preeent day.
They are characterised by the fact that the current is produced
by blades or vanee fixed to a shaft, revolving at a high speed,
lie air lying between them is whirled round and flies off tanfren-
tially at the tips, like a stone from a sling. The space occupied by
this air is at once filled by supplies coming in at the centre, and
the process goes on continuously. The centrifugal ventilators or
fans are generally used as exhausters — that is to say, they are
arranged so as to suck air out of the mine, instead of forcing it io.
They can claim the merit of great simplicity, and of being capable
of withdrawing very large volumes of air.
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VENTILATION.
495
Four types of f ana very lately used in this country at the preeent
day are the following: Capell, Guibal, Schiele and Waddle.
The CapfM fan (Figs. 5S1 and 5 8 a) ctondsts of two concentrio
cylindrical chambers, each provided with aix curved vfuies or
blades, the convex sides of which are turned in the direction of
tiie rotation. The cylindrical shell or drum, b, between the two
sets of vanee coutaina openings, or portholes, d d, allowing tbe air
to paas from the innw to the outer chambers. There is one
such opening between every two vanes. The air contained
between any two of the inner vanee, e, is thrown out by centri-
fugal force when the fan revolves, and posses at a high velocity
into the corresponding outer chamber. Here it is supposed t^i
strike against the concave vane, and give back to it the greater
part of the impulse received from the inner chamber. Tbe
object of the inventor of this and of other fftns is to discharge
Vio. jSi
Fig. 5S3.
the air wiUi the least possihle velocity, for velocity imparted to the
outgoing air means work done to no purpose, or, in other words, a
diminution of the useful effect of the power employed in driving.
The advantage claimed for the fan is that it succeeds in eSect-
ing this object even when driven at a high speed, and that,
therefore, it can do a Urge amount of work in spite of it« com-
paratively small diameter. The smallness of the fan of course
reduces its first cost. It is not only capable of withdrawing large
quantities of air, but also of effecting a considerable diminution
of pressure.
The fan may be mode with an inlet on one side only or with on
inlet on both aides. It runs in a spiral casing, not fitting closely,
which gradually gives a larg^ and larger outlet for the air and
then finally discharges it into an expanding chimney. Figs. 581 and
5S2 show a double inlet fan, a being the dose vertical diaphragm
separating it into two ports. A special passage (/an drift) brings
the air from the upcast shaft to the ventilator, which is set in
notion by a belt ^ven by the fly-wheel of a pair of horizontal
engines.
These fans are made of diamrters vaiying &om 8 to 15 feet ;
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496 ORE A2TD 8T0ME-MINI]:^G.
the width of the Bmall ones is 7 feet, that of tha largest 11^ feet ;
they are driven at speeds varying from 180 rerolutioiiB p^*
minute in the case of the largeet fans, to 300 in the case of the
amaUest, Under these conditions the smaileet fan is said to be
capable of passing a volume of 100,000 cubic feet of air per
minute, with a diminution of pressure {yxUer-gaugt) of 2^ inches,
whilst the large fan moves the enormous quantity of 300,000 cubic
feet per minute. The power required is estimated at 60 I.H.P. in
one case and iSo in the other.
The Ouibtd fan, brought to us from Belgium (Fig. 583), has
deservedly been a favourite for many years. It is a fan with eight
ten straight
Fig. 583.
blades, which are
not set radially. An
importout peculia-
rity, introduced by
Quibal and since
copied by others, is
the expanding stack
or chunney, which
gradually lessens
the velocity of the
air as it travels
towards the point
of discharge into
the outer atmo-
sphere, and the slid-
ing shutter, a. The
shutter enables the
opening of the tan-
casing into the ex-
panding chimney to
be regnlated at pleasure : if this opening is too big, eddies are
formed and air re-enters the fan ; if, on the other hand, the opening
is too restricted, an unnecessary amount of force is required to
work the fan, and the air escapes with too great velocity. By
careful regulation the best possible effect is attained.
The regulating shutter has been greatly im^ved by Messrs.
Walker Brothers of Wigan, who make the opening in the form of
an inverted V, with the object of producing a gradual instead of a
sudden change as each blade passes into the endoeed part of
the casng. The consequence is that the amount of vibration is
greatly reduced and the fan rendered nearly noiseless. They
build their fans entirely of iron or steel.
Quibal fans are made of diameters varying from 20 to 46 feet,
and widths varying from 6 to 13 feet. Fans jofeet in diameter
are usually driven at a speed of about sixty revolutions per
minnte, and the large fans of 40 to 46 feet at fifty revolutiima.
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VENTILATION.
497
The SehieU fan is somewliat like the Guibal. It has the same
expending chimney, bat the bladee are curved and the casing is
notcloBB {Fig.5S4) ; besides,
the width of the blades is Fiq. 584.
not the same throughout.
The blade is widest in the
middle, and then it de-
creases both towards the
centre of the fan and to-
wards the tips. It is a
small tan. compared with
the Quibal, the diameter
varying From 5 to 20 Feet,
width tiGsa I to 3 feet.
The speed of driving is 500
revolutions per minute for
the smallest Fans and 1 1 o per minute for the largest. The air
is alwajs taken in on both sides.
We come lastly to the Waddle fan, which differs from those just
described by running open — that is to say, it is not enclosed in any
external casing (Fig. 585). It is a very flat hollow truncated
oone, with the base closed and a central opening on the other
Fia. 585.
side. Originally the blades a b were curved, as shown in the &rure,
but latterly they have been made radial ; e c are some 1^ the
outer plates. The air passes in at the centre and is discharged
at the circumference. These fans are made with a diameter
of 30 to 45 feet. A recent improvement is the addition <rf a
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498 OEE AND STONE-MINING.
divergent outlet — in other words, the two rims {trojecting beyond
the bUdes are inclined outwards. The velocity of the air leaving
the fan in thus lonered, and lees power is required for driving.
A Waddle fan, described by Mr. Walton Brown,* had the following
dimensions :
Ft. In.
Diameter to periphery of divergent outlet 36 4
„ ottheeitremities of the blades "" "
„ „ inlet riOK
Width at outlet
„ „ periphery of tan
The Waddle, like the Quibal, is a slow-running fan, which can
be driven directly from the engine without the aid of belts or
gearing.
Professor Luptonf has designed a fan, which he calls the
MediufH fan, in which he considers that he lias brought
together the good points both of the large fans, such as the
Guibal and the Waddle, and of the small fans, such as the
Schiele and the Capell. It in from 15 to 25 feet in diameter.
TEBTINa THB ftTTAIjITT OP THE ABB.— In a well-
regulated mine the manager should be able to determine the
quality and quantity of the air circulating in the workingK, and
tiie efficiency, from a mechanical point of view, of the machinery
employed for ventilation.
A knowledge of the quality of the air is necossaiy for two
reasons : it may contain gases capable of causing accidents by
explosion or suffocation, or it may be polluted by gaseous and
other impurities likely to injure tiie health of the men who have
to breatiie it.
Flxe-damp. — Though ore and stone miners are rarely expceed
to any danger from fire-damp, exceptional cases arise in which car-
huretted hydrogen is emitted naturally or formed artificially in
mines, as mentioned in the beginning of this chapter. Itisther^ore
essential that the miner should have some knowledge of the
means employed in testing for fire-damp, even if he is not going
to manage a colliery. However, the subject must be treated
laiefiy, and the student desirous of further information may
be referred to treatises on ooal-mining.
Indications of fire-damp are afforded by the singing noise made
by the gas if it is issuing forth in large quantities from moist coal,
by its bubbling up in water, and by the cracking noise of bubbles
as they burst ; but its presence is commonly detected by its effect
upon the flame of a lamp burning oil, benzine, alcohol, or hydrogen,
llie additional brilliancy which it imparts to a platinum wire made
incandescent by the passage of an electric current may aleo be
employed as a test, or the diminution in the volume of a measured
• " Waddle Patent (1890) Fan," IVmu. Fed. In*t. M. E, vol. ii., 1890-
91. p. I73'
t Notes on the Hedimn Fan, Proe. fed. Imt. M. E., voL i., 1890, p. £5.
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VENTILATION. 499
quantity of air, exposed to the action of a red-hot palladiam or
pJatinuiii wire, causing combuHtion.
The lamp employed ehonld be a safety lamp, for fear that an
accidental ignition of the gas should cnufie an explosion. A few
safety lamps will be described in the next chapter. They are fed
with vegetable or mineral oil, or with a mixture of them. In test-
ing for "gas," the wick is drawn down until the yellow flame almost
disappears, and the lamp is held in the place where the fire-damp
is supposed to be present; on account of its specific lightness
it lodges against the roof, and it is there, if anywhere, that it
is most lively to be found. If fire-damp is present in suffi-
cient quantity, its combustion produces & pale blue "cap" (halo,
or aureola) around the little fiame, and the greater the proportion
of fire-damp, the higher the cap. According to Professor
Galloway * 2 per cent, of fire-damp in the air will give an exceed-
ingly faint cap ^ inch high, whilst 4 per cent, gives a conical cap
J^ to I inch high. If a lamp fed with benzine is used, the phe-
nomena are plainer. The appearances of the flame burning
in mixtures of air and marsh-gas of different proportions are
well represented by coloured plates in a report made by Professors
Kreischer and Winkler,+ and in the Proceedings of the Austrian
Fire-damp Commission.^ With i per cent, of fire-damp there
is a faint aureola, and with 2 per cent, it is plain, conical at the
top and ^ inch (10 mm.) high ; when the proportion is increased
to 3 per cent., there is a well-defined cap f inch (20 mm.) high.
By using a dead-black background, it is claimed that Ashworth's
modified benzoline safety-lamp § will give a distinct cap ^ inch high
with J per cent, of fire-damp.
The blue non-luminous flame of alcohol enables still smaller
quantities of fire-damp to be made known, and the Pieler lamp||
* " On the Sire-damp Cap," JVoc. iSaath Wain Irut, Eng., rol x., 1876-7,
p. ago,
t " UnterBnahnngeD fiber Sicberheitslampen," Jairb. f. A Berg- wnd
Satlenicaen iia K. Sadtttn, 1884, p. 54, and plates il. to vl.
X Yerhandhaigen der CentrahimitA der e*terreieliuchen Commiuion xun
Ermittltatg der xwedaadtiigiten Sicherheitmiaiuirtgdti gtgen dU Jixploeimi,
tddagendtr Welter in Bergatrken, 3 Heft. Viemia, 1S90, plates ii. and iiL,
p. 215.
S Clowea, " On the Application of the Hydrogen Flame in an ordinary
Salety-liunp to the Detection and Measuiement of Flie-damp,'' Free.
Boy. Soe., vol. li. iS(|3, p. 90.
II Fieler, Veber einfaohe Meikodm air UnlcTtudiwig der QruheiacetteT,
Aii-la-Chapelle, 1883. Kreischer and Winkler, op. cil., p. 77. C. Le
Neve Foster, " On the Heler Lamp for indicating Email quantities of Fire-
damp," jFVani. Oecl. -Soe. ilanchetler, vol. ivli., 1884, p. 252. Broockmann,
" UDtersDCbung der dtirch Sompfsas hervorgebrachten ErscheiniiDKen
der Pfelei-LAmpe," Aalagtn zuni Hawpt-Beridite der PreutiUflieri StMag-
aett«r CovtrniiiuM, ToL i., p. 129, vol. iii,,p. 167. and plates. Walton Blown,
" The Pieler Spirit-lamp as a Fire-damp Indicator," Tratu. If. E. hit.
M. E., vol. zzxriii., 189O1 p- i77 and plates. Austrian Fire-damp Com-
missioD, op. eit,, ^te iv.
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Soo ORE AND STONE-MINING.
ie based upon tlus fact. It begins to indicate with ^ per omt.
of fire-damp, and even with % per cent, the cap or aureola is
3 to 3^ indies high, and clearly recognisable; with i per cent.
it is Dearly 4 inches hijth.
Cheaneaa * obtains a plainer and more brilliant cap by adding
a little nitrate of copper and nn organic chloride to the alcohol,
and Stokee has introduced the imprOTement of combining a
delaehablt aloohol-reserroir with an ordinary safety-lamp, and
so enabling the official to test with the oil or the spirit flame at
pleasure.
Mallard and LeChatelier pointed out the value of the hydrogen
flame as a fire-damp indicator in a report to the French PireHlamp
Commission, and Pieler made use of it for testing samples of mine
air which were brought to a laboratory at the surface. Quite
recently Prof . Clowesthasconstructedahydn^eulampttufficiently
portable for use undnrground in the working places themselves.
The lamp is so constructed that it will bum either an illuminat-
ing oil or hydrogen as required. A little tube is brought up through
the oil reservoir, and, on tuming a oock, a jet of hydrogen issues
fcoth close to the ordinary oil flame. It ignites at once, and
the wick of the oil flame is pulled down till it goes out ; the
non-lnminous hydrogen flame now serves as a delira.te indicator.
The oil flame is relighted from the hydrc^en flame when the
testing is concluded, and the gas is then turned off. The cap
with { per cent, of fire-damp is f inch (17 mm.) high, and with
I per cent, it is | inch (zz mm.) high. The hydrogen is contained
in a small steel cylinder which can be attached to the lamp in the
form of a handle.
The combination of a very delicate testing apparatus wil^ the
ordinary lamp has the advantage of enabling tiie official to do
bis work with one lamp instead of two.
Livmng's^ patent gas indicator depends upon the fact that
fine platinum wire, made red-hot by the passage of an electric
current, will glow with greater bnlliancy when there is fire-
damp present in the atmosphere than when there is none.
This phenomenon is due to the heat given off by the com-
bustion of the fire-damp in immediate contect with the wire;
and the greater the heat, the more the wire will glow. The
increase in brilliancy correspcmding to a given percentage of fire-
* " Notes anr nn Donvel indioateor deerison; " "BsmieeSeotn^daDBles
mines avec llDdicatear de gtison de Q. Chesnean ; " " Instruction poor
I'emploi de I'lndlcateiir de grison de G. ChBraeaii," Jaa. dea Mima, Faiis,
1S9Z and 1S93. Complet-rendui Soo. Ittd. Mitt., 1S94, p. 35.
" On the AppUoatlon of the Hydrops Flame in an ordinarr Safetj-
lamp to the Detection and HsBunremaiit of Fire-damp,* Pr«e. Bog.Soc,
vol-U, 189Z, -
f Liveing, On an ItulrumaU Jor the DeUetion tMnd Meaturemtiit o/lnjlam-
mable Go* in tie Atmo^h«re of MiiM. L. CUrk, Uairhead and Co., Weat-
mUuter, London, 1S81.
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VENTILATION. 501
damp is measured hy a small photometer, which cannot be
tmderstood without a figure.
Shaw's apparatus is based upon the principle of detenniajng the
limits of inflammability of gaseoiis mixtures, or, in other wordK,
of asoertaining the precise degree of dilation which renders the
mixture just capable of being ignited. It consists of two main
parte, an ingenious mixing apparatus and an exploding chamber.
By the aid of the first, a mixture of pure air with inflammable
gas, or with mine air, can be prepared in any desired proportion b,
and then driven into a cylinder, where it meets with a naked fi&mo.
If the mixture contains a sufficient proportion of inflammable gas
to explode, a loose stopper is blown out and strikes a bell, giving
an audible signal. By making a succession of experiments, the
exact volume of mine air required to bring a known mixture of
gas and air to the ignition point can be ascertained, and from this
the percentage of fire-damp is determined. Samples of mine air
can thus be tested at the surface with a considerable amount of
accuracy by any intelligent foreman.
C^bonio Aold. — Two evils are fearecl from the presence of this
gas in the atmosphere of mines — either suffocation when the pro-
portion is large, or injuiy to health when the proportion is smaller.
If the gas is issuing from the rocks, it settles down at the bottom
of the excavation in virtue of its specific gravity, and men have
been asphyxiated by descending into shafts or w^ls in which the
gas bad accumulated without their knowledge. Where danger of
this kind may be apprehended— for instance, in mines known to
be liable to emissions of carbonic acid, or in the case of old work-
ings that have not been recently entered, the usual test is
lowering a lighted candle. If the candle is found to bum
brightly, it is concluded that there will be no danger in making
the descent ; if it goes out, it is evident that the air ie unfit to
support combustion and human life; if it bums dimly, there is
need for the greatest caution.
The ore and stone miner also relies upon the candle for testing
the air of his working place, in cases where the proportion of
carbonic acid falls very far short of that required to produce suffo-
cation. He is apt to consider that if the candle burns freely when
held upright, and does not go out when moved quickly from side
to side, the ventilation must be good. Dr. Angus Smith states in
his report to Lord Kinnaird's Commission* that this is a fallacy,
and he considers that the candle test affords no distinct sign that
the air is bad, until the impurities have reached an amount beyond
the maximum which is consistent with good ventilatdoc. Thus,
the candle affords no indication of the presence of ^ per cent, of
carbcmio acid ; if the percentage is greater than this he says that
men should not be allowed to work, and, to use his own words,
"it follows therefore that the candle, as used, is only valuable
* Op. eit. Appendix B, p. 354,
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5oa ORE AND STOME-MINING.
when the ur is so bad that no one should be &llowod to remain
in it."
He is of opimon that the carbonic acid of dwelling rooms
should not be allowed to exceed 0-06 or 0*07 per cent., and
agraes with Pettenkofer,* who lays down o'l per cent, of the gas
as the beginniDg of decidedly had ventilation. The latter eays :
"A series of ezaminationB have resulted in the conviction that
one volume of carbonic acid in 1 000 volumes of room air indicates
the limits which divide good from bad air. This is now generally
adopted and practically proved, always provided that man is the
only source of carbonic acid in the space in question." Other good
authorities f write to the same effect.
Such small percentages of carbonic acid, which are wholly
unrecognisable by the candle test, can he readil; detected and
easily measured by methods which are quite within the powers of
an ordinarT mine agent.
Angut Smith's Proeeai. — The first process is one proposed by
Dr. Angus Smith % in 1864 — viz., shaldng a known quantity of
lime-water with a known volume of air, and observing whether
there is sufficient carbonic add in the air to neutralise the lime.
The only alteration I propose is the use of phenolphthalein as an
indicator, instead of turmeric paper or rosolic acid.
The necessary apparatus consists simply of :
I. One 8-oz. bottle aad cork.
3. Uae S-oz. bottle and oork.
3. One bottle of Itme- water with excess of Ume.
4. One pipette or raeasare holding \ 01.
5. Foar )-0E. bottlsa corked.
6. One {-01. bottle containing an alcoholic solation of phenol-
phtbalein.
7. One piece of india-rubber tnbe, aboat a foot long.
According to Dr. Angus Smith, lime-water is fairly constant
in strength, and sufficiently so for his process of sir-testing.
After the bottle (No. 3) has been well shaken up several times
with the excess of lime, the solution is allowed to stand till
it is quite clear. \ ounce of it is measured exactly, end poured
into the 5 -ounce bottle, which is then filled up with distilled water
or boiled rain-water. This gives a solution of one-tenth the
strength of the original lime-water. Add a drop or two of the
solution of phenolphthalein, and the lime-water at once assumes
* Tht Biiaiioiu of the Air toihe Ctothatue Wear, the 36u»e ae Live in, and
tlu Soil me Zheellon, Abridged and translated b; AnguBtus Hest, London,
1873.
f ParkeB and de Chaumont, " A Maiuuil of Pmetieal Si/giene," 6th
edition, London, 1883, p. 153. He7niott Tidy, " Ba-aiSHioi of Jlodtm
Cliemittry,'' London, 1878, p. 102.
; Op. cil. Appendix B, p. 339. C. Le Neve Foster, "On One of Dr.
Angus Smith's Methods of Testing Air," Trant, JUin. Attoc. and Jtut.
Corn., ToL il., part 3, p. 40.
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VENTILATION. 503
a beautiful pink colour, which remaina so long as there is any
lime un-neutraliaed. This dOuto lime-water is now of a
Btrength that J ounce of it will neutralise the carbonic acid in
an 8-ounce bottle,* if the air in it contains ^ per cent, of this gas
by volume. This percentage has been propoeed as a standard
which should not be exceeded.
Id order to make a test, fill the 8-ouace bottle with the air
of the place, by sucking out ita contente with a piece of india-
rubber tube, of courae taking special care not to breathe into
it afterwards ; then add ^ ounce of dilute lime<water, cork the
bottle and shake it. If the pink colour disappears, the air
contains more than ^ per cent, of carbonic acid ; if the colour
is not discharged, the air contains less than that amount. If
the colour fades slowly, and does not finally vanish tmtil after a
great deal of shaking, it may be assumed that the percentage of
carbonic acid does not greatly exceed ^, whereas if the disappear-
ance is rapid after a few shakes, the contntry of course is the case.
It need hardly be said that the accurate of the process depends
upon the precision with which the solution is measured, and for
this purpose a pipette, or a burette, will do better than a
graduated glass cup. I think it best to carry each separate i
ounce of lime-water in its own bottle, and it is well to see by actual
measurements that ^ ounce can be poured from the little bottle,
for a few drops always remain behind.
However, even if all precautions are taken, the observationa
cannot pretend to vie witli Dr. Hesse's method (p. 505) in accuracy,
because changes of temperature and pressure alter the weight
of the air contained in the 8-ounce bottle. Luckily in the case
of mines, the two sources of error act in oppceite directions,
and sometimes may neutralise each other, the tendency to expand,
owing to increased temperature, being counteracted by a greater
barometric pressure due to the depth of the mine.
A leather case containing an 8-ounce bottle and four half-
ounces of lime-water, by means of which four tests can be made,
measures only 7^ inches by 3^ inches by 2| inches, and is sufficiently
portable to be easily carried, even when climbing up " rises " or
*' slopes."
hang^t ApparatMa. — Instead of simply deciding whether or no
the carbonic acid exceeds the proposed stuidardof o'35per cent, by
volume, it may be sometimes desirable to ascertain the precise
amount of the impurity. This can be done by Dr. Lunge's f little
apparatus which I described some years ago. ^ The method was
*Tfae eiact size shoald be 8^ 01., the Tolame of air being ;{{ oz.,
because the lime-vrater occapies 1 01. ; bat an ordinar; 8-os. bottle is
near anonEh for tbo purpose.
+ Zur Frage dtr VtTUiiatum, Zurich, 1877.
; C. Le Neve Fostei, " On Dr. Angus Smith's Method of Teating the Air
of Mines and DiTGlliiig-houses,'' Ann. £ep. Min. Atioc Com. and Devon
for 1881, p. 7.
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504
ORB AND STONE-MINING.
originally Bugseeted by Dr. Angus Smith * and his procMS consisted
in pumping tbe air criF the working plaoe throngh lime-water until
a knows standard of milkiness or opacity of the Boluticm was
attained. Bad air would cause the standard amount c^ opacity
with very few strokeB of the pump, whilst good air required many.
I now find it convenient to use ]ime-water of known strength, and
to go on with the pumpings until the pink ooloor given by phenol-
phtiialein is discharged. This method is, I consider, mors
aoourate than endeavouring to reach the proposed standard of
milkiness.
Dr. Lunge's apparatus consists (Fig. 586) of a No. i, or
1 -ounce, flexible baU-syringe A, connected by a piece of india-
rubber tube B, with the beat glass tube D; at the point G a
slit about g inch long is cut in the tube witii a very sharp knife.
Via. 586.
Fiti. 587,
This acts as a valve. The tube D panses very little bey<Htd
the cork of the bottle E, which holds about two ounces. F is
B. tube extending nearly to the bottom, connected by a small
piece of india-rubber pipe with the valve-tuhe G, shown oa
a larger scale in Fig. 387. It is simply a piece of glass tube, with
a ring made of indl&-rubber tube, supporting a gfasa valve. The
top part of the valve is flat, not spherical, and it allows free
passage of the air when in the position shown in the figure.
If you squeeze the ball A, supposing tbe bottle pcutly full of
water, the valve in Q rises and prevents any escape of liquid, and
the air rushes out at C. On allowing the ball A to expand again,
the aht 0 closes, air enters through G, and bubbles up from the
bottom of Finto the bottle.
In order to make the bottie as portable aa possible, I prefer to
use one piece of tube containing the vaJve instead of having a
separate valve-tube as shown ; however, this is a mere debul of
minor importance.
• Op. dt., p. 238,
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VENTILATION, 505
Half an oaoce of lune-wftter or baryta-water of known atrength,
and coloured pink by pbenolphthalein, is put into the bottle ; the
ball is squeezed and allowed to expand, and a definite volume of
air is drawn into the apparatus. A good shaking is given, and
continued long enough to cause the absorption of all the oarbonic
acid bj the solution. This process of squeezing the ball and
shaking the bottle is repeated until the pink colour is discharged,
and knowing the strength of the solution and the volume of air
passed through, it is easy to calculate the percentage of carbonic
acid contained in the air,
Lungereckona that each squeese of a No. i ball causes the entry
of 33 cubic centimetres of air. The " No, 1 " means a one-ounce
size; it really contains about 28 cubic centimetree, but the whole
of this cannot be expelled by squeezing. To save the trouble of
making calculations each time, a table should be drawn out once
for all with two columns, the first giving the num.ber of squeezes,
and the second the correeponding percentages of carbonic add.
Further details are given by Winkler,* but the form of bottle
shown by Mm, with a long projecting valve tube, is not so portable
as the one which I use with the valve contained in the piece of
tube inside the bottle. My case is not laiger than a field-glass,
and holds all that is necessary for making six determinations
onderground ; it is meet convenient to wear it upon the belt, in
the same manner as the " Tscherpe-Tasche," or pouch of the
Saxon miner.
Where greater accuracy is required, I recommend Hesse's
apparatuSgt with which I have made a very lai^e number of
carbonic acid determinations in the working places of mines. The
leather case, which contains the necessary bottles, burettes,
barometer and thermometer, measures 15 inches by 91^ by 5.
Oxygen. — The unfitness of air for breathing is indicated not
only by an excess of carbonic acid, but also by a deficiency of
oxygen. When there is both a lack of oxygen and an undue
proportion of carbonic acid, it is evident that some process
of oxidation has been going on, such as the respiration of the
miners, the burning of candles or lamps, the slow combustion of
coal or pyrites, or, lastly, the putrefaction of timber or other
organic matter in the mine, AJI four causes may combine to
render the atmosphere unhealthy.
Dr. Angus Smith considers that when the proportion of oxygen
* Lehrbueh der tedinitehen Qtaanalyu, Frelbeiv, 1885.
-f Hesse, " Anleitaug lor Bestimmuti^ der Kohlenaanre in der Lnfr,
nebat einer BeschrsibBDg dea bierzu notbigen AppanUs." Evlenberg'a
VieTUljaJirttekrifi JUt geriehllirhe Hedidn und effentlidia Sanildliinaoi,
iieut Foige, voL xixi., Berlin, 1879, p. 357. HeBBe, ''ZurBestinunang der
Kohlens&ure in der Lnlt," Ibid., vol. xzxiv., ISSr, p. 361. Winkler,
ATiieiUtTig zur ehemitdim Unttriuckung dtr Induitrit-tfait, Kreiberg, iSjy,
p. 375- Winkler, Lehrbuch der ttdmitehen OaioHcdytt, Freibei^, 1885,
p ^■
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5o6 ORE AND BTONE-MINING.
by volume Iios been reduced below 20*9 per cent., the atmoepbere
18 impure, and wlien the percentage descends below 20*6, he calls
it exceedingly bad.
Lindemann'a A pparatiu.— Far determining the percentage of
oxygen in the air of mines, the simplest apparatus ia that of
Lindemnnn, which is figured and described hj Winkler.* It is
based upon the property poeseased by moist pbosphorus of combining
with the oxygen of the air at ordinary temperatures; if a large
surface of phosphorus is presented to the air, the absorption takes
place comparatively rapidly at t«mpentures between 60° and 70° F.
(15' to 20° C). This apparatus, and instruments of a similar
class in which an alkaline solution of pyrogallio acid is used
as an absorbent of o^gen, are better suited for use in the
laboratory than for making determinations in the mine itself,
unless it is desired to oon£ne the obserrations to one spot.
The box containing Lindemaun's apparatus is 17J inches high by
10 j inches vide, and 5^ inches deep, and the weight when ready
for use is 8 lbs. The tUmensions and weight are not prohibitive,
but it would not be safe to carry such a box with its glass vessel
of phosphorus when climbing up stopes by a chain ; and there
are two other important objections to its use undergroimd : (i) it
is difficult to manipulate such instruments with the dirty hands
inevitable in mines ; and (2) in each working place it would be
neceesaty to wait until the whole of the apparatus had assumed
the temperature of the surrounding atmosphere, because unless
this were done the results would be erroneous from changes of
volume. However, it is easy to bring up samples in suitable
glass bottles, and then submit them to analysis m a laboratory
above ground. The manipulations are not dijficult, and any mine
agent capable of doing the delicate work required for an accurate
mine survey or the assay of an ore, would find no difficulty in
making determinations, suffioiently exact for his purpose, of
carbonic acid and oxygen in underground air.
When the task consists in determining the proportion of such
gases as sulphuretted hydrogen or the quantity of organic matter,
he must oall in the services of the chemist.
HSASUBina THE QTTAirriTY AKD FBES8TTBE
OF THE AZB. — More attention is paid by miners to measure-
ments of quantity than to determinations of quality. The
quantity of air passing through any given passage can be calcu-
lated by measuring its sectional area and ascertaining the speed
of the current. In the old days there were two rough metjiods
of estimating the velocity of an air-curi-ent : (i) by carrying
a candle in the hand and regulating the pace so that the flame
was not deflected either backwards or forwards, the rate of
walking was therefore precisely that of the current; (2) by
' Lelirhuch der lechniidieii Otuanrdyte, Freibeig, iSSj, p. j8.
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VENTILATION. 507
exploding a little gunpowder and obMrving how long the Bmoke
took to tr&vel aloug a measured distance in a level. These
metbods have been abandoned in favour of Bpeed-measuring
instruments known as anemometers.
Anemometers. — Two kinds may be mentioned : fan-plate type
and windmill type.
Dickinson's * is one of the former claes ; it consists of a plate
of mica, hung from two fine bearings, and connterpoised so that a
very lighc breeze will deflect it from its norioal vertical position.
The deflection is measured by a quadrant attached to the frame
of the fan-plate, and, instead of marking the angles, it is usual to
show by the graduations the velocity of tbe air in feet per minute.
The instriunent is graduated by actual experiments upon a test-
ing machine.
In anemometera of the second type, the speed of the air-
current is determined by the number of revolutions of an
instrument provided with vanee like those of a windmill. Biram's
anemometer, one very commonly need, has eight or ten vanes
made of mica or vulcanite or aluminium, attached to arms radiating
from a small central wheel. The instrument is held up at arm's
length in the current, and by the aid of suitable gearing and dials
and pointers, like those of a gas-meter, it registers either the
number of its revolutions, or the rate in feet or metres at which
the air is travelling, during a short period of time, measured by
a watch.
As a slow current of air will not make the vanee move round,
from its being unable to overcome tbe friction of the parte,
the makers usually supply a certificate with each instrument
showing what correction must be made on this account. The
correction is detei-mined by a testing machine, on which the
anemometer can be whirled round at various rates of speed ; it
can then be seen how far the readings of the anemometer agree
with the known velocity at which the whirling has been carried on.
Messrs. Davis and Son, of Derby, make a self-timing anemo-
meter which dispenses with the use of a watch ; it is held up in
the current and when the vanee are considered to be revolving at
a constant speed, a catch ia pressed ; this allows the vanes to act
on a pointer which indicates on a dial the velodty in feet or in
metres per second.
In making observations with the anemometer, it is essential
that an airway of uniform section be taken ; levels which are
lined with brick arching are wull adapted for the purpose. If
the airway is not regular, eddies will be set up interfering with
the accuracy of the results. A further necessary precaution is
taking observations in various parts of the area chosen for
the experiment, because the velocity is not uniform through-
* DiokiniiOD, " On Measuring Air in Mines," Traai. Hanehtiter Geel. Soe.,
ToL xi?., 1878, p. 31.
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So8 ORE AND STONE-MINING.
oat tliia area. The mMU of the reaUingfi gives the mean velocity
of the current. In the instructions htid down b; & committee
kppoiiit«d by three of the British Mining Iiistitut«e,* the atv& &t
which the observations are made has to be divided up hy horizontal
and vertical strings into sixteen equal parts, and a reading of the
anemometer taken in each.
Water-Qange. — For calculating the efficiency of the veuti-
lating machinery, a mere knowledge of the volume of air passed
through the workings doee not suffice ; in addition, its pressure
has to be determined, or rather the difference between ita
pressure and that of the external atmosphere.
The instrument employed for this purpose is the manometer,
or water-eauge. It is a glass tube bent in the form of a U, partly
filled with water; one leg is in communication with the outer
atmosphere and the other with that of the mine. Usually it is
placed in the engine-honse of the fan, and a pipe ia carried
from it into the fan drift. The suction of the fan causes the
pressure of the air in the mine to be lees than that of the external
atmosphere, and the diminution of pressure is indicated by the
difference in the heights of the two columns of water in the U-tabe^
The manner in which a water-gauge acts can
YiQ tgs easUy be explained to students by construct*
ing a model from a WouUTs bottle (Fig. 588),
' or any other bottle or jar which will take
three pieces of glass tube. If the mouth is
applied to the piece of india-rubber tube A,
air can be diuwn through the bottle in the
direction indicated by the arrows. With a
certaiD degree of suction, the retdstanoe
caused by the passage through the tube B
becomes plain, and a strong air current is
not produced until the external pressure is
decidedly greater than that inside the bottle,
which is indicated by the rise of the coloured
water in the gauge C, as shown in the figure.
In the instruments employed in mines, the difference in
pressure is measured by a s<»de which can be moved up and down
by a screw, so aa to make the zero correspond with the level of
the water in the free limb. It usually varies from i to 4
inches. In order to prevent the water in the gauge from
oscillating rapidly up and down, which would happen if the
current were irregular, the tube connecting the two upright
limbs is contracted, or, what comes to the same thing, the gauge is
'Joint Committee ot the North of Buglasd lastitnte of Hfuitig and
Mochuucal SiiRmeerB, Mldlaod Institute of HIdIdd;, Citil, and Mechanical
Engineers, and the Sooth Wales Institute of Engineers, " On Hechanical
Ventilators, 18SS," ''Observations to be Hade, and Instmctions to the
Engineers.'' IVani. N. E. Inal. M. M. Eng., vol. sxivii., 1887-8, p. 190.
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TENTILATION.
S09
made in the form of two chambers with a glaaa front and a connect-
ing aperture, the size of which can be regulated by a tap. This
ifl DiclduBon'B water-gauge,* which is a brass box 6 inches high,
4 inchea wide, and 3 inches deep, with a partition in the middle,
ntakiDg two chambers each a inches by 3 inches. A glass front
shows the two columns of water, and a scale, graduated into
inches and tenths, enables the difference in their heights to be
measured.
Effioiency of Ventilating Appliances. — The effideacy of
a fan or other ventilator is calculated by comparing the work
which it does in drawing air through the mine, with the work done
by the steam in moving the piston of the engine that drivee it.
The work done in moving air is reckoned from the volume
displaced and ^^ pressure ; the former is ascertained by the
anemometer and the latter by the water-gauge. As a cubic foot
of water weiglis 62425 poimds, each inch indicated by the water-
gauge wiU represent pressure of one-twelfth of this amount, or 5-2
pounds per square foot. A depression of the wat«r-gauge of 2 inches
will mean 3 x 5*3 or 10*4 pounds pressure per square foot. Id
common parlance the word " depreesion " is understood, and
the miner speaks of a "water-gauge" of a inches, for instance,
meaning thereby a depression of the water-gsuge.
The work done is looked upon ss that of pushing a volume of
air through a pipe under the pressure indicated by the water-
gauge. Let A represent the area of the airway in square feet, Y
the velocity of the air current in feet per minute, as measured by
the anemometer, W the water-gauge in inches, 5*2 pounds being
the weight of a column of water one inch high with an area of
I square foot, S the useful effect of the ventilator,
Then
E = (A V W X 5-2) foot-panada per Dinnte.
To ascertain the horse-power it is only necossaiy to divide by
33,000, and we may state :
B = A T W K 5-3 g p
33.000
Thus to take an example :
If the quantity of air in circulation, A Y, is 100,000 cubic feet
per minute, the water-gauge 1*5 inches, the useful effect of the
ventilation will be :
«^«5JLLSJL£2 = 33-63H.P.
33.000 ^ ^
The officiency of the ventilating plant is the ratio of the horse-
power of the ventilation so mlculatod to the indicated horse-
power of the driving engine.
■ Diokiiwoii, op. at., p. II.
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Sio ORE AND STONE-MINING.
SupfKisuig that the indicated hoise-power was fovid t« be 45,
we should have the ratio of 23*63 to 45 ma denoting the efficiency.
In other wordu :
EffldenC7 = -'—2= '5251 or 5351 percent,
Besistanod oaosed by FriotloiL. — ^The amount of power
required to overcome the friction of the air currant in passing
through the paasnges of the mine must be studied, because it is
on important f&ctor in the problem of ventilation ; and unless its
effects are appreciated the best method of arranging the ventilar-
tion will not be understood.
The amount of friction depends upon fire conditions :
1. The Im^b of the airmj, which we may call.L.
2. The penmeter of the airwdj, P.
3. The sectioQKl area ot the airway, A.
4. The velodty of the current, V.
5. The UBtare ot the rnbbing aurfsce, the effect of which maj be
eiprassed bj a co-efflcient C.
The friction is directly proportional to the length of the airway
and its perimeter ; in other words, if there is twice as mudi
rubbing surface, there is twice as much friction. It is invereely
firoportional to the sectional area of the airway — that is to say, a
Bvel 7 feet high and 10 feet wide will cause only one-half of the
friction produced in a level of the same height, but 5 feet wide.
Lastly, the friction increases aa the square of the velocity.
These relations may be expressed by the general formula :
Besifitanca dne to fiiction = 0
It is evident from this formula that it is desirable to shorten
the path of the air as far as possible; much is done in this
direction nowadays by " splitting " the air current — that is to say,
dividing it into separate branches instead of causing the whole
of the current of the downcast shaft to travel through the entile
length of the workings.
With regard to the second factor, the perimeter, it may be
well to notice that a circular section is the one with which a given
length ot perimoter affords the largest area. Take, for instance,
the case just dted of a rectangular airway, 7 feet high by 5 feet
wide, with a perimeter of 24 feet and an area of 35 square feet.
A circle having a circumference of 24 feet would have an area of
45'S square feet, or 30 per ceut. mure than the rectangle.
Splitting has also the effect of reducing the velocity required
for the passage of a given quantity of air through the mine.
Suppose that 90,000 cubic feet are wanted per minute in order
to ventilate the mine ; if the mine is divided into three equal
and similar districts and each is ventilated separately by ooe-
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VENTILATION. S»»
third of the main current, the velocity of the minor currents
need be only one-third of what would hare been necessary if all
the air had had to travel by one road. Reducing the velocity
to one-third means, according to the formula, a diminution of the
resistance caused by friction to one-ninth.
The co-efficient, 0, varies according to the nature of the
rubbing surface ; in smooth passages, such as tboee of levels lined
by an arching of brick, it will naturally be less than in the
irregular airways along the working face, or in an airway with
&ames of timber, forming a succession of projecting obstacles at
short intervals,
FIO. 589.
If the resistance due to friction, <a, in other words, the pressure
required to ovwcome it, la measured in pounds per square foot,
then taking L and P in feet, T in thous^ida of feet per minute,
and A in square feet, the co-efficient C varies from o'oo2 to 0014*
according to the nature of the airway.
Mining engineers owe a debt of gratitude to M. Murgue f for
his graphic representation (Fig. 589), which illustrates the influ-
* ElweD. " An Acconnt of Bxperimenta on the RcBialanoe to AJr Currents
in Mines," and Walton Brawn in the discoBsion. Tram. N. E. Irat. M. E.,
vol. xxxviji, r888-9, p. 305-218.
'f " BecbeiofaeB Eip^rlmeatales but la Perte de Cliarges dana lea ^rcoars
Sonterrain*," BiA Soc. Tnd. ifi'a., voL vlL, 1893, p. 5 ; and tiaoslaUon In
TVaiu. Amtr. liuL M. E., toI. zzii., 1893-1894.
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513 ORE "AND STONE-MINING.
enoe of the ddea of ui airway in a moat Btriking faaluoii. He
compttne three kiods of airwajPB : one arched, A B C ; a BeooncI,
D E F O, in ban rock ; and a third, H IJ K, lined with timber ;
and he ahowB that, with the dimensions given in the figure, all
three airwavs produce the same amount of friction, or cause the
same loss of " bead." In other words, the arched passage ABC,
in spite of its small dimensions, offers no greater resistance to the
air cuirent than the large timbered tann^ H I J K ; whilst jon
may put the brick lining ABC inside a level D E F O without
in any way requiring additional ventilating power. He concludes
that it ia more important to diminish the friction in the air-
possagee than to aeiek for better ventilatore, and that the miner
can lessen the resistanoe to aiivcurrents not only by increasing
the size of his levels, but also by lining them with brick or stone
in pUoe of timber, and by keeping them as stniight as poemble.
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CHAPTER XI.
Itefleot«d daylight— Candles, candle- holders — Lamps and lamp oil — WelU
llt^ht^MagneBium wire — Sufetr lamps : Davy, Claany, Mneseler,
Marsant. HepplewhiCe-Ora; — Locks; lead rivet,, magnetlo bolt,
Cavelier'E lock — Coal gaa— Electricitf .
HiNBS are usually lighted b^ candlee, torches, ' lampH, gas, or
electricity.
In a few ca^es the miner does his work without artificial light.
Iq sinking oil-wells in Burma,* the quantity of explosive gaa is
HO great l£at no naked light can be used, and even if the work-
man had a safety lamp, be would be unable to stay below ground
long without being afiected by the noxious atmosphere. He
therefore carries do light at all, and has his eyes iKuidaged up
before he goes down, because otherwise it would take longer for
his eyes to become sccustomed to the semi-darkness of the bottom
of the pit, than the whole time he can stay below groaud.
Befleoted DKylight. — For sinMng oil-wem in Japan t
reflected daylight is used. A piece of yellowish translucent oil-
paper, about 5 feet by 3^ feet, is suspended over the well at an
angle of 45° and throws light down the pit. The wells are about
3^ feet square, and are dug to a depth of 600 to 900 feet.
In driving the Bell tunnel at the New Idria quicksilver mine,}
in California, there was a disastrous explosion from the igni-
tion of some inflammable gas, and after this occurrence the
tunnel was lighted by the reflection of the sun's rays. A mirror
was kept at the mouth of the drift at the proper angle to effect
this, and with a straight tunnel and in a sunny country like
California the device answered perfectly.
Candles. — The candles used by miners are very frequently
the so-called " dips " — that is to say, they are made by dipping a
wick into molten tallow and allowing it to take up grease; the
process is repeated several times, until the thickness of tallow is
sufficient. The wick is made of ootton, or of cotton and linen.
* Noetling, Bee. OtoL Surrey India, vol. zziL, 1S89, p. 97.
t Bodwood, "Fetroleam and Its Products," Joar. Soc Arti, toL zszIt,,
1886, p. 832.
X Becker, " Geology of the QaioksUvei Deposits of the Paclfio Slope,''
J/bn. O.S. Geot. Sun-fi/, vol- xiii., 1888, p. 30S.
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514 OBE AST) STONE-MINING.
At Sn&Ubeach Mine, in Shropehirs, the manager stipulates that
the wick Bh&U be made of three threads of cotton and three of
linen ; this is folded, and the candle therefore has a wick of six
threads of cotton and six of linen.
The Else of the candles is reokoned hy the number that
go to a pound, which varies from 30 to 6. Candles of six-
teen to the ponnd are very commonly used by the miners, while
the agents, who want an extra amount of light for their exajn-
inations, find it convenient to have "eights" and occasionally
"sizes." These candles require snuffing from time to tinie,
tbongh I have seen snuffless dips employed in exceptional cases.
In hot mines speciftl dips are necessary, for those made of
ordinary tallow become soft and bend down.
As a rule the British ore-miner holds his candle in a lump of
clay, which forms a very convenient support. It has the advan-
tage that the candle can be stuck up at any point where it is wanted,
without a moment's delay in seeking for a place to fix it; it is also
readily stuck upon the hat when the miner 4ants to climb a ladder
or a chain. But the clay must be soft, well kneaded, and free from
stones or lumps; from time to time it has to be moistened, and
care and practice are required in order to work it down properly
as the candle is consumed.
In the Forest of Dean many years ago, tlie candle was stuck
into a cleft stick, which was carried in the mouth. Nowadays metal
candle-holders are used instead, with a point which can be stuck
into the timber or a crevice in tbe rock.
The tallow candle has the disadvantege of guttering in a
draught and of causing a good deal of smoke, which is bad if the
working place is at all close. The Festiniog men guard their candles
against draughts, when walking to and from their work, by shades
made out of old meat-tins with a handle of wire. If there is
much water dropping down a shaft the miner can protect his
candle by a shield of tin-plate nailed to a piece of wood.
Qrease is bad for amalgamation, and sperm candles are adopted
in some gold mines, as they are less objectionable than those made
of tallow. Paraffin, steazine
^o. 590. and "compodte" candles may
* be and are used in place of the
common dip; they do not
stand a stroog draught or
drops of water so well as the
latter, but they give lees smoke
and do not gutter so much.
Moulded candles are conve-
niently carried by a holder,
such as is seen in tbe United States, made of a small rod of iron
with one end bent into a handle and the other pointed (Fig. 590).
In the middle there is a cylinder of thin sheet iron which has
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LIGHTING.
515
spring enoogh to clip the candle firmly ; a (tharp hook, sticking
up at right aaglee to the horizontal rod, enables the holder to be
hung on to the eligbteet little projection, if there is no convenient
OTevice or piece of timber into which its point can be thrust. The
Australian has a somewhat similar holder made of wire, known aa
the "spider."* The wire is about one-sixteenth of an inch thick,
twisted as shown (Fig. 591);
Fio. 591.
the spiral portion holds the
candle, and the little hook will
hang on to the face c^ the
rook.
A. candlfr-holder of some
kind is more convenient to an
official who has to make notes
underground, than the usual
lump of clay ; with the latter
it is di£Scult to keep the note-
book clean,
Torohw.— Torches are em-
ployed in a few exceptional
inatancee. The foremen at
Falun, in Sweden, carry
torches oonsisting of bundles
of pine sticks held together
by an iron ring, and some gold mines in Japan f were lighted a
few years ago by torches made of dried bamboo twigs; tires of
pitch-wood have been used at night when washing down gravel
by the hydraulic process.; lArge underground chambers may be
lit up for a short time, in order to examine the roof, by bumiug
a bundle of wood shavings soaked with naphtha and petroleum.
Lamps. — lAmpe vary much in shape and sise. The Sicilian
miner has a lamp of the simplest construction imaginable ; it is a
mere open cup of unglazed pottery, about 2 inches in diameter
iuid I inch deep, with a Lttle lip for holding a cotton wick, which
lies loooely in the olive oil used aa an illuminant. It is nider
than the old Roman lamps found at Pompeii, which somewhat
resemble those still employed in the Htuti. The latter are
provided with a hook, by which they can be held between
the thumb and forefinger when climbing ladders; the hook
has a sharp point which the miner can stick into a timber
prop or a crevice in the rock while at work. The body of the
lamp is closed ; it has a tube for the cotton wick and a hole with
a screw-plug through which the supply of oil can be replenished.
* Annual Smirt of Uke Seerttart/ Jar Uina, Victoria, for th» ]/ear 18S8,
Melbourne, 1889, p. 36.
t FreohSTille, "Tbe Hinini; nnd TreatmeuC of Gold Ores in the North.
ofjMiaii," Jfin. Pnclnit. C.E., rolljiy., 1883-84, p. 169.
I Bowie, E^raulic Mtning in California, New York, 1885, p. 346.
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Si6 ORE AND STONE-MINING.
A pricker for tnmmiiig the wick is attached by a light chain. A
BDuller but similar lamp is met with in France, aorthem Italy,
and parts of Spain ; the body is leaticalar, and is suspended by a
loDg hook.
The foramen in the Harts mines prefer a somewhat similar lamp
in which they can bum tallow ; it is an open tray with a rim
around it and a lip for the cotton wick ; a large lump of tallow
lies in the lamp at the opposite side to the wick, and if the agent
wishes to make a flare-up, to illuminate a working place more
thoroughly, he need only push a good supply of tallow towards the
wick holder, and soon obtains the desired eSect.
In the Mansfeld copper district the miner has a small tin lamp
which can be hung by a wire loop to a hook on the hat, if he is
climbing, or be placed upon the ground in the working place. It
has a double case, the outer one serring to catch any oil whidii
may run over from the spout-like wick-tube.
The Saxon miner still adheres to the " Blende," a wooden case
lined with tin-plate or brass, in which he carries a small globular
oil lamp. The case is useful in walking or climbing in very
draughty parts of the mine, and can be hung from the neck by a
leather strap.
In Scotland and in some parts of the United States, a small but
serviceable tin lamp,of the shape shown in Fig. 59 >, is very common.
It can be hooked on to the bat when climbing
Fig. 592. ladders, or on to the rock. Olive oilorrapeoil is
burnt in the lamps just described, and the miner
carriee with him a supply in a httle flask.
Lamps have the advantage of being cheaper
anl cleaner than tallow candles, but the latter
do not seem likely to be displaced in English and
Welsh ore mines, though the Scotch lead miner
prefers the former.
Mineral oils are oocasJonaUy used instead of
vegetable oils for ordinary miners' lam[». At the undai^rouod
stone quarries near Bath the men employ small lamps fed by ben-
zoline, which is held by a sponge in the reservoir. Petroleum
"Hurricane" lamps for lighting up pit-bottoms and landings
{platt) are not uncommon, and even levels are lit up in this way
by hanging a lamp at each bend in the road. This saves the
miner the trouble of carrying a lamp, and the light is quite
sufficient for the purpose of tramming, even if the stretches are
somewhat long.
Flare lamps, similar to those used by " Cheap Jacks," which
generate gas from naphtha, or a .mixture of naphtfia and
pe^leum, flowing into a hot burner, may occasionally be seen
in parts of undergiound slate quarries, where a good deal of light
is required for hooking-cn and unhooking waggons.
Wells Idght. — Among recent inventions for illuminating, I
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LIGHTING.
517
mnet specially mention the Wells light, which, after being largely
used for surface works, is now finding applications underground.
The Welle light is a contrivance for burning tar oils converted
into gas, when forced through a heated burner by pressure pro-
duced by a hand air-pump.
Fig. 593 shows the principal parts of the lamp, A is a closed
4^1inder made of steel boiler plate, B is a pump worked by the
handle 0, which can be used
for pumping in either air or
ml ; whilst the light is run-
ning, the oil is drawn from a
bucket by the piece of hose
D. E is the oil which has
been pumped in, thereby
compressing the air above it
to about 30 Ibe. per square '
inch. On turning the tap G,
the oil is forced up the pipe
U to the generating tubes
I I, which hare been pre-
viously heated by lighting
some cotton waste and oil in
the tray K. The pi-elimi-
nary beating may also be
effected by burning a spray
of the oil, produced by a
special starting appliance
forming part of the lamp.
The oil in its passage through
the hot burner I is converted
into vapour, which issues
forth from the nozsle L and
produces a flame of 1 2 to 30
inobea in length, with a con-
sumption of half a gallon to
i^ gallons of oil per hour,
giving a light of 500 to 4000
candles. U is & plug con-
nected to a rod which serves
the double purpose of letting off the air quickly at any time,
and also of gauging the depth of the oil in the cylinder.
The lamp is easily carried about from place to place. The
smallest size and the larger one, No. 3, have both been employed
of late in the large chambers of the Festiniog Blat« mines for
examining the roof and sides, and also for plate-laying. The
pressure of the air in the reservoir is kept up by a few strokes of
the pump from time to time.
The brilliant light emitted by burning msgnesium is utilised at
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5i8 ORE AND STONE-MINING.
Festinii^, in addition to the WelLt light, for examining the
nndergroucd chambers. The ftgent8 of Bome of the mines
carr; a little stock of magnesium ribbon in their pocket-books,
and set fire to a piece if they wish to throw a powerful light apon
any particular spot whii^h may require special attention. At
two of the mines the metal is burnt in a special lamp. It
consists of a coil of magnesium ribbon about J inch wide wonnd
upon a reel, which is fed by clonk-work, b6 that it ieeaeti
from a tube at the focus of a silvered mirror about 8 inchen in
diameter. The lamp is held by a convenient handle, and the light
can be directed on to any given point without dazzling the eyes.
The ribbon is consumed at the rate of about to inches per minute;
the lamp can be started and stopped by touching a catch which
controls the clock-work, and there are means of altering the speed
at which the ribhon is fed forwards.
Safety Lamps. — The subject of safety lamps — that is to say,
lamps which can be used in an atmosphere containing a certain
amount of inflammable gas without fear of causing an explosion
— may seem out of place to some who suppose tbat their
use is confined to coal pits : but when we recollect that fire-
damp has been met with in mines worked for diamonds, gold,
iron, lead, quickalver, salt, silver, sulphur, and tin, and
further that a lead mine in this country is lighted entirely
with such lamps, and that they are indispensable in the
caoe of ozokerite, it is evident that miners generally should
have some knowledge of the principles upon which they are
constructed, and the manner in which they are used. Howerer,
in the mines with which we are dealing, safety lamps are the
exception, and, therefore, the subject can be dealt with in &
summary manner.
The construction of the safety lamp is based upon the fact
that gauze of a certain mesh, made with wire of a certain gauge,
is capable of cooling* burning gases to a point below that at
which combustion will take place — in other words, it will pre-
vent the passage of £ame. Therefore, when a lamp enclosed in a
suitable cylinder of this gauie is placed in an atmosphere con-
taining fire-damp, the inflammable gas inside the envelope wilt
burn without igniting that which is outside.
I will now describe briefly the lamps most commonly in use in
mines containing inflammable gas ; they are named after their
inventors, viz., the Davy, Clanny, Mueeeler, Marsaut, and Hepple-
white-Gray lamps.
The ordinary Z>aw/ lamp (Fig. 594)* consists of a brass oil
vessel b, on to which is screwed a cylinder of wire gauxe a,
about i| inches in diameter and 4J to 5J inches high. Tbe
* The materials uEed in conttmcting the Ismps are Indicated thai :
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LIGHTINa.
5»9
cylinder ia further closed at the top hj a cap of wire gauze e,
which overlaps the main gauze for a distance of i inch to t^
inches. In the centre of the oil-vessel is a round tube containing
a cotton wick, which can be trimmed from the outside by a piece
of wire / pasging Up through the bottom. The gauze used has
28 holee or mesfaee per linear inch, or, in other words, 784 per
square inch. The wire varies slightly is size ; some which I
very carefully measured was *oi6 inch in diameter, and was
27 S.W.G. A maker of repute
probably intended for No.
informs me that he usually
employs No. 30 of the old
B.W.Q. Speaking roughly,
the holes are ^ inch (J mm.)
square. Three rods c.attacbed
Delow to a ring screwed on
to the oil-vejsel and above to
4 plate, protect the gauze to
a certain extent. The lamp
is carried by a strong wire
ring fastened to the top
plate d. Bape, colza, or seal
oil, alone or with the addition
of petroleum, are used as il-
lumioanta.
The Davy lamp has several
grave defects: m the first
place it gives very little light ;
and secondly, as pointed out
by the Boyal Commission on
Accidents in Mines,* it will
fire an explosive mixture if
the vdocity of the current exceeds 6 feet a second According to
the photometric teste made for the Boyal Commission by Professor
Clifton.t the light of the Davy lamp varied from 7 to 22 percent,
of that of a standard candle ; these were laboratory expenmenta,
in which the light was not further diminished by the accumula-
tion of dirt, greeae, soot, and coal dust upon the gauze, as may
often happen underground, and nothing is said about the absence
of illumination immediately above the lamp.
With the powerful ventilating ourrente in use nowadays, the
second defect is a very real one ; it is sometimes overcome by placing
the Davy lamp in & cylindrical tin case with a glass window.
It was very natural to attempt to remedy the first defect of
the Davy lamp by using glass instead of gauze, far the lower part
oF the enclosing cylinder.
In the Clanny lamp (Fig. 595), constructed upon this principlei
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Sao OKE ASH STONE-MINING.
the ftir which feeds the flame cornea in through the gauze just above
the glaas a, deecends along its inner face and goee to the wick ;
the products of combustion then pass up the centre. Nothing
separates the descending current of air from the ascending current,
and consequently the oil, from want of a direct supply of fresh
air, does not always bum bo brightly as it does in a lamp fed
from under the gauze ; but the light ia far better than that of
a Davy lamp. The letter b represents one of the metal rods for
protecting the glass. Professor Clifton's experiments usually
gave a6 to 50 per cent, of the light of a standard candle, or, on
an average, more than twice as much light as the Davy. In a
current having a velocity of more than 6 feet a second it behaves
like the Davy, and i^iites an explosive mixture.
Mutttler't lamp (Fig. 596) may be conveniently described as a
Clanny lamp, with a chimney a fixed above the flame, and attached
at the level of the top of the glaas to a dia-
Fia. 596. phragm or horizontal partition of wire gauze
b. The path taken by the air is shown by
the arrows. The fact of the inward current df
fresh air being kept separate from the outward
current of foul air assists the illuminatang
power of the lamp. The wick is sometimes
flat.
The Mueseler lamp, which is the only one
allowed in fiery pits in Belgium, is a favour-
ite in many countries, and leaving aside it«
use in collieries, I may mention that it is the
only lamp employed at the very dangra:otis
ozokerite mines of Boryalaw and at the Mill
Close lead mine in Derbyshire. It has Uie
merit of going out in an explosive atmosphere,
and of so removing a cause of danger. The
lamp is extinguished because the chimney is
unable to carry off the products of combustioa
quickly enough; they spread out under the
bottom edge of the chimney, and pollute the
fresh current to such an extent that it becomes incapable of
su^orting the combustion of the oil.
!nie lamp will not stand being jerked or inclined, for any-
thing which will turn the currents out of their proper course
causes the bottom part of the gauze to be filled with the products
of combustion and puts the flame out. It is evident that when
the lamp is held in an inclined position, all the foul gas will not
go up the chimney, and that some will become mix^ with the
inward current; a jerk downwards checks the supply of air
passlDg in through the gauze, and again the lamp is extinguished.
On the other hand, it resists a horizontal current better than
the two lamps mentioned previously. If the lamp is struck
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LIGHTIKa
S"
1 ezploa
i may sometimes take place
obliquely hy the current a
inside it.
Before coDclnding this very short account of the Mueseter
tamp, it is important to point out that a mere diaphragm with a
chimney does not necessarily conatitute a lamp of the original
Belgian pattern. The dimensions of the paia are carefully
prescribed by law in Belgium, for it has been found that a
slight departure from them may affect the properties of the lamp
very materially.
A lamp which has come largely into use of late years, and
especially in this country after the favourable report of our Royal
Commission, is that of If. ManmU, of Bessiges, to whom miners
FiQ. S97-
are indebted for many useful investigation s (Fig. 597). It is of the
Clanny type— that is to say, it has a glass cylinder with the air
entering above it, and no chimiiey ; but it has the extra safety
afforded by a second or even a third gauze, and a bonnet or shield
of sheet iron. These additions enable it to resist curreats of 2000
feet per minute ; other advantages are an illuminating power of
about two-thirds of a standard candle, simpUcity and strength, for
the gauze is protected by the shield from accidental blows of the
pick or other sources of injury. The outer shield adds somewhat
to the weight of the lamp, but the slight diminution of portability
is amply repaid by the increased security which it affords.
The EeppUiohiU-Gray lamp, with some modifications intro-
duced by Ashworth (Fig. 598), is of a totally different type; the
wick is fed with air coming in below the glass, through a ring
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Saa ORE AST) 8T0NE-MINIKG.
of wire gauze d, od the inaids of an. annular chamber. When
testing for " gaa," the openings at the bottom of three brass
tubes, through which the air passes into the annular chamber, are
oloxed, and the lamp draws its supply of air from the top of tubes.
The path taken by the air is shown by the arrows ; b b are the
holes by which the products of combustion escape. The glass
is QO longer cylindiical, but is made in the form of a trooratod
cone, with the object of iUumina^g the roof ; the amallneee of
the top of the shield a conduces to the same desirable object. If
the inside of the glsss is blackened at the back, the effimeocj
for testing is decidedly increased, as images of the flame, such as
are reflected from both sides of the ordinsjy glass, no longer
trouble the observer. This lamp has the further advantage
for testing that it takes in its supply of air from the top, und
will therefore test a layer of air close to the roof which could
not be examiiied by on ordinary lamp, except by tilting it so much
that there would be danger of its going out.
LoeJu. — Jn order to prevent careless and imprudent men from
risking their lives and those of their comrades by opening their
lamps, it is necessary to lock them securely before they are taken
into the workings. Various devices hare been propoeed and
adopted.
A little bolt screwed in by a key like a large watch-key, through
the ring holding the glass or the gauxe, was thought at first to
offer BuliiciBDt guarantee of security ; but it was soon found that
ingenious miners could (nek a lock of this kind without difficulty,
and other plans had to be devised to baffle their skill. Tho most
common systems employed are the lead rivet, the magnetic bolt,
and the Ouvelier fastening.
The lead rivet is placed through two holes, one in the brass ring
holding the glass and the other in the oil-vessel ; it is then firmly
squeezed with a pair of nippers, and thus impressed with a mark,
which can be changed from day to day if necessary. When this
has been done, the lamp cannot be opened without cutting the
rivet, which would at once be noticed when the miner handed it
in at the end of the shift. The lamp-man easily cuts the
rivet before proceeding to clean the Isjop; the pieces of lead
are collected, melted up again, and once more cast into rivets. The
cost of this very efiective method of locking is but slight.
Several inventors have resorted to magnetism in order to
obtain an unpickable form of lock, and Wolfs fastening is one
of this description. It ctmsists of a bolt held in its place by a
spring, which can only be drawn back when the lamp is placed
against a very powe^ul magnet. This form of lock is laigely
Cuvelier's ingenious fastening, which gives great satisfaction at
some French collieries, may be described as a vertical bolt which
ke«ps the lamp locked until it is set free by hydraulic |
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LIGHTINQ. 523
The two ends of a piece of metal tube, bent into the form of a
circle, come cloee together under the bolt, whilst on the oppomte
side tJiere is a projecting tube with a very small hole. If hydraulic
pressure is exerted on the inside of the tube by means of an
accumulator acting through the little hole, the two arms tend to
tttraighten out, and the ends move a. little away from one another ;
in so doing they allow the bolt to fall from its own weight and the
pressure of a spii'al spring. The operation of opening is very
quickly performed, and the hole in the projeoting tube is so small
— only J- to ^ of a millimetre in diameter — that the quantity of
water used in insignificant. The hole is on the under side of the
tube and has not been found to become choked up by dirt, as
might have been expected.
Ofts. — Gas is employed for lighting pit-bottoms, hanging-on
places, or sidings, where there is a large amount of traffic.
Sleotrio Light. — Up to the present time, owingto its want of
portability, the electric tight has not displaced candles and ordinary
lamps in the work of " getting " minerals, save
in a few special cases. It is true that various £'10. 599-
small portable incandescent lamps have been in-
vented and tried, but until lately they have failed
to satisfy all the conditions which are necessary
for commercial success.
More promising than its predecessors is the
Sussmann lamp, which is now coming into the
market. A (I4g. 599) is a steel case enclosing a
dry storage batt«ry; Bisan outer protecting cylin-
der of glass, held between four upright rods, G ;
D is the vacuum bulb with the filament which
becomes incandescent ; K and F are conical
whitened reflectors destined to make the best
possible use of the light. The back half of the
glass cylinder is whitened for a similar reason.
The lamp is af inches square at the base and
8 inches high ; it weighs 3 lbs. 10 oz. (1*64 kil.).
One pattern is said to give a light of one candle-
power for fourteen or fifteen hours, and another
three candle-power for nine and a half hours.
The advantage of this lamp over those previously
brought forward is the absence of any liquid. The interior of
the battery is solid, and consequently the lamp can be held or
laid in any position. The company owning the patents is ready
to make contracts with nune-ownera to supply lamps, charge
them daily, and keep them in repair for 41:1. per lamp per week,
or about what oil alone is oosting at the present time.
As regards its safety, it is stated, as the result of numerous
experiments, that the smallneHS of the filament prevents any
chance of its igniting explosive mixtures, in the event of both the
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524 ORE AND STONE-MINING.
outer cjliuder and the bulb being bn^en. Like all other dectric
lamps, it has the defect of afibrdiog no indication of fireniamp or
carbonic acid.
Where a fixed light can be used — in other words, where the
nature of the excavation to be, lighted is not rapidly changing —
the electric light is rendering incalculable services. Thus, in
ainldiig shafts, a few incandescent lamps hung from an electric
cable enable the miner to do faia work under unaccustomed con-
ditions of brilliancy. He not only gets better illlumination, bat
he is rehered from all trouble about c&ndles or lamps, and can set
about his work as a navvy would at the surface. This means a
saving of time which is often well worth paying for. While
blasting la going on, the lamps are drawn up out of the way of
stones which might be hurled up and break the glasses.
Fixed glow lamps form a -convenient and desirable means of
lighting up pit-bottoms, on-setting places, levels and sidings when*
the traffic is large, and ladder-ways and man-engines which are
much frequented.
When the area to be illuminated is large, an arc-lamp may be
employed with advantage. Among the fint succeesful applications
of electric lighting to underground excavations may be mentioned
that of M. Blavier at the Angers slate quarries.* In the year
1879 he fixed two Serrin lamps in one of the large underground
chambers with an area of 2400 square yards, and he found that
they gave light enough for sll the men at work. The total cost,
reckoning everything — viz., coal, carbons, repairs, labour, deprecia-
tion of plant, and interest on capil&l — was 50 francs a day ; the
gas formerly in use cost 54 francs a day and gave much less light.
The large chambers in the salt-mine of Maros-Ujvar in Hungary f
have been lighted up by electricity since 1880. The cost is some-
what greater than that of the tallow, oil, or petroleum formeriy
in use ; but, per contra, the illumination is better, the men can do
mora work and are more easily supervised, whilst the air of the
mine is not deteriorated by the products of combustion of the
lamps. Slanic salt-mine in Roumania has been lit with the
electric light in a similar manner since 1883.
In a previous chapter I described the working of the thick bed
of lead-bearing sandstone at Mechemich by large undergronnd
chambers, which eventually are allowed to collapse. Of late yeaiB
arc lights have been largely used for illumination, although the
number of men in one chamber is never more than six and often
not more than two. The great advantage derived from the use
of the powerful light has been the possibility of removing with
safety thousands of tons of oro, which otherwise would have been
left undergound for fear of accidents in taking it down.
* Blavier, " L'Eclairage ^lectriqTie bux Ardoisifties d' Angers," Annalet
du JUinu, Ber. 7, vol. ivu., 1880, h. 5.
t Ot*t. Ztittekr. B. u. H. W., iSSa, p. 396.
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LIGHTING. 525
It its proposed to uau arc lights with reflectors, eimitar to the
naval search lights, for ezamiuiag the roofs and sides of the large
underground chambers in the Welsh slate mines.
Arc lights stand in good stead when work haa to be done at
night above ground. Thus, at Bio Tinto, the great open-cast
is lit up by two arc lights, one at each end of the major axis of
the elliptical pit. In the same way two arc lights of 2000 candle
power are used for night-work in washing down auriferous gravel
at the works of the CMceola Company in Kevada.* As the use of
electricity spreads for the purpose of traasmitting power, we may
naturally expect further development of the lighting of parts (^
mines fn>m the same source.
• JSag. J/i'n. Jour., vol. li., 1891, p. 630.
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CHAPTER XII.
DESCENT AND ASCENT.
At first sight this subject migbt seem scarcely to deserve asepuato
chapter ; but if one cocsiders the time occupied by the miner in
going to and from his work, and recollects that his hours are
reckoned " from bank to bank " — *'.«., from the moment he leaves
the Burface till he reaches it again— and if one further dwells upon
the terrible waste of energy involved by climbing up and down deep
shafts by ladders, it will be admitted that the question of deeoeDt
and ascent requires to be discussed.
Where mines are worked by adit levels, the men naturally walk
in along the ordinary roadways. Such mines, however, are
exceptional, and the workmen generally have to climb down and
up by laddei'S, or are lowered and raised by the winding
machmery. The means of access to and from the wordings may
be classified as follows :
I. StetH and Blides.
3. Ladders.
3, Backet or CAgt.
4. Uan-engiae.
Steps and Slides. — If the dip of a seam or vein is small,
an inclined pathway, leading down throogh the old workings,
fonns a safe and [deasant travelling road into the mine, and it
has the further advantage that the ponies or hmsee can be
brought out at the end of each shift.
'When the inclination reaches 30* it is well to have regular
steps, instead of making the men scmmble down an irregular
path ; it is true that the miner, accustomed to the road, does not
loee BO much time as a stranger in picking his way along a rough
or slippery track, but still a bad path causts a little nnnecessary
delay which is best avoided. Steps are much Itvs fatiguing than
ladders placed so flat that part of the weight of the body has to
rest upon the- arms.
Steps may be cut in the rock itself, if it is hard enough, and if
not, wooden or stone stairs can be put in, with a handrail. When
the dip is too high for making the stairs straight, they may be-
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DESCENT AND ASCENT. 327
ajraoged in a zigzag line, provided that the excavation affords
sufficient epace. The height of the steps should not exceed
8 inches, so as to avoid a fatiguing lift of the foot.
In ports of the Sicilian sulphur-mines,* where the dip does not
exceed 30° to 35°, the steps are fnim 8 to lO inches high and 12
t<' 14 inches broad, and occupy the whole width of the travelling
road ; if the dip is from 40° to 50°, two sets of steps are made, so
that the level of the tread on one side corresponds with the middle
of the height on the other. This system is known as that of the
acaioni roUi, and greatly facilitetee the ascent up such steep
roads.
In some of the AoBtrian salt-mines the men descend by wooden
slides inclined at angles varying from 30° to 50*, flattening at the
bottom so as to reduce the velocity gradu^ly ; the miner can
increase his speed by leaning forwards or lessen it by leaning
bock. The ascent is by steps.
Ladders. — Ladders are very largely used in ore-mines all over
the w(H:ld, but they vary a good deal in different countries. In
Mexico and in Chili, the common ladder b merely a pole with
notches at the sides for receiving the feet. These ladders,
especially when worn, are better fitted for barefooted or sandaled
miners than for those wearing a heavy and unyielding boot.
The so-called " centipede ladder," met with in out-of-the-way
parte of Australia, and even sometimes seen in Europe, is very
properly condemned by the inspectors of mines in Queeusland.f
It is made of a single pole, often a sapling with the branches cut
ofi', with auger holes through which wooden pegs are inserted at
regular intervals. The projecting pegs form the mngs of the
ladder. If such a ladder is new, with the pegs set evenly and
firmly, and placed at a proper angle, it will serve for shallow
depths; but ladders of this description are usually put in by men
who are not good at carpentry, they are hung vertically, the pegs
are uneven originally or are allowed to get rotten, and the suc-
oessive ladders are not securely joined; the task of climbing then
becomee a dangerous one.
The ordinary ladder consists of two sides find a eeriea of rungs
{ttavea, Cornwall). The principal points that have to be considered
are the material, the size, and the mode of fixing.
In this country the mine ladder is most commonly made with
wooden sides and iron rungs. The sides are easily formed by
putting a sawcut through a plank as supplied by the timber-
merchant, 2 inches thick by 8 inches wide, giving two pieces 4 by 2
inches ; pitch-pine is lai^ly nsed on account of its durability.
The two sides are fastened together temporarily, and auger holes
bored through them both, so that they match exactly. The rungs
" Parodi, :S*W Bilriaiime delio ffoljb in Slcilia, Florence, 187J. p. 34.
t Ann. Sep. Dip. JUina, QueeniUaid, for th* Year 1889, p. 123; 1890,
p. 130.
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538 ORE AND BTONE-MININO.
ara made ot pieces of round iron, J to J inches in diameter. It is
tru» that one may see g inch iron employed for the rungs ; bot^
leaving aside the question of safety, this is false economy. The
thin rung wean quickly, if there is much traffic, and soon hAs to
be replaced, entailing an ezpenite which would have repaid the
extra cost of the thicker iron in the first instance.
On the Continent wooden rungs are common, and oak is
preferred on account of its durability ; the wooden atave is otten
made flat, instead of round, so that it may last longer, and iron
sides may be seen where dry rot is very bad. A ladder made
entirely of wood is lighter than oae with iron staves, and
this is an advantage if h has to be moved about much. In places
where an ordinary ladder would be knocked to pieces by blast-
ing, such as the bottom of a shaft in course of sinking, a short
length of chain ladder is put in ; the sides are made of pieces
of chain, and iron rungs are attached at suitable intervals.
Wire rope is also used for the sides of ladders, and Rochebeao
uses steel tube for the rungs. He supplies the ladders of this
description, which can be rolled up into a coil and kept in readi-
ness in case of an emergency.
A veiy important point is the distance between the rungs : it
should be choeensoasnot to cause too great a lift of the foot at each
step, whilst at the same time the number of steps must not be
increased out of reason. Experience shows that a distance of lo
inches from centre to centre is very suitable ; ladders with a step
of II inches or 1 2 inches are far more fatiguing to climb. The
two end rungs often have collars, and, like them, the middle rung
is screwed at the ends for nuts ; these add to the general strength
of the ladder; the aides are thus kept permanently about 11
inches apart. If not secured in some fashion the ends may come
together a little and the middle bulge out. It is advisable to have
a uniform pattern for all the ladders in a mine, such as 14 feet,
for instance, and when an old ladder has tobe replaced, a suit-
able new one is ready in stock, without any delay for taking
meesaremente or making it. Two such ladders joined together
form a very convenient length for a " footway " in a shaft; they
make a ladder 28 feet long, and allowing 4 feet to project above
the platform, for safety and comfort in getting on and off, theie
remains a length of 24 feet for actual Climbing between the plat-
f c»'ms or sollars. The two ladders can be fastened together by an
iron strapping-plate on each side, held in position by the nate of
the two terminal rungs. Where the ladders have plain rungs at
the ends a strong wooden cleat nailed on to both laddra^ makes
the connection. In making the joint between two ladders, care
should be taken to maintain the proper distance between the
staves and the regular inclination ; for when once a man has got
into the rhythm, so to say, of climbing, he is liable to miss his
step and fall if a rung fails to coino just where he expects it.
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DE30BNT AND ASCENT.
5»9
Fig. 600 repraents a ladder* made eatirel^ of iron, such as la
lai^y used in minee in the north of Franoe. I^e aides are of flat
iron, 7 X 70 mm. (aboat ^ x 3 J ins.) and the ruugB are of round
inm, 22 nun. (g inch) in diameter; they are 353 mm. (9*9 inches)
from centre to centre. Three of the mngs are bolts with nuts,
and the others are riveted; the manner c^ joining two ladders
bf a cotter bolt with a sqnare end is evident
from I^. 601. The iron xoAy be galvanised
to prevent rusting. ladders of this descrip-
tion weigh 10 kil. per metre (30 lbs.) per
yard.
Platforms {mOots, Cornwall) should be fixed
at short intervals; though our British law
allows them to be [daced 60 feet apart, the
distance can be rednoed with great advontagie
Fio. 600.
^^^^
1 1 •
•
s
, i .
1 •
■
=^^
^^
to 18, 30, or 34 feet in perpendicular or
highly inclined shafts. A much shorter
interval would mean too many changes, and
akmgw one would render falls more danger-
cos, besides cnrtailing the number of enforeed
short rests, which are a relief in climUng up
from great depths. - One side of the ladder
may be fastened to timber in the shaft
by strong staples; and if not, it should be
kept rigid by stays, so ss to prevent any
swaying,
' Lastly cfMues the question of the angle at which the ladd^
should be inclined. The mine-owner should spare no pains to
render the "traveUing" as safe and as easy as possible, and
should recollect that the miner climbs with the leMt amount of
fatigue, when the greater part of the work of raising the body is
thrown upon the muscles of the legs and not upon those of the
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53©
ORE AND STONE-MINING.
arms; the port played by the arma ahould be keeping the
body in a proper poeitioii and preveatiDg falls. It may here be
noted that the miner does not olimb a ladder like a bric^jayer or
a hotue-painter. The latter place their hands upon the sidee of the
ladder ; the miner graepe the rangs, and even if his foot slips, or
if a faulty rung gives way under him, be has a chance of aaviiig
himself. In climbing down be frequently misses every altenutte
stave with his hands, or, in other words, he makes two steps with
fais feet for one grasp with the hand.
The most convenient angle for ladders is aboat 30* from
tbe vwtical ; if they are much flatter than this, the arms
have to be used in order to |wevent the body from blUng
forwards ; if they are steeper, the arms have to lift part of the
weight of the body. In either case there is fatigue for the arms,
and in the latter the dangm- of foils is increased ; these dis-
advantages become very marked when the ladders are placed in a
vertical or overhanging position. Laddersao fixed are prohibited
by law in this country, for it is not only the life of the man who
falls which is endangered, but he may sweep off several m^i
beneath him. Unfortunately, our present law does not go quite f tu-
enough ; it forbids a vertical ladder, but permits a ladder inclined
at an angle of i* or 3* from the vertical, provided the shaft is not
large enough to admit of any better arrangement. In other words,
it does not compel the mine-owner to sink
Fio. 603. ^ shaft large enough for a proper ladder-
road. The Belgian law,* enacted twenty-
one years before ours, is more wisely
worded ; it decrees that no ladder shall be
inclined at an angle of less than 10° from
the vertical.
Furthermore, of the two arrangemente
shown in Fig. 6oz, A is better than B,
because it not only affords a greater in-
clination for the ladders, but also renders
it less likely that a man will drop through
the opeoing {manhMj in tbe platform
{soQar) if he loses his hold and falls. In
planning the regular permanent ladder- road
for the miners, it is well to avoid shafts
in which other operations, soch as winding
OT pumping, are going on. By law, in this country, the ladder
oompartment haa to be partitioned off from the winding cwnpart-
ment ; a better plan, if possible, is to provide an entirely separate
shaft for a footway. In vein mines, a number of the winzes can
conveniently be set apart for " travelling " purposes. Occasionally
the ladderway is made double in the upper part of the mine, so
* ArrBtJ royal dn Janvier 1851, Article a.
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DESCENT AND ASCENT. 531
fts to prevent Iobb c^ time &t the change of the shifts, when an
ascendhig Btream of men meets a Bimilar descendmg stream.
Some of the mattere joBt mentioned may seem trifling, but,
leaving aside the question of safety, the economy derived from
fixing the ladders at the best possible inclination is by no means
small. To make this apparent, we must recollect the depths to
and from which men have to climb — viz., 300, 400, and even
500 yards or more. It is, therefore, important to save every
unnecessary expenditure of energy, which, though trifling for one
ladder, be<»mes considerable if very frequently repeated. When
a mine has reached a depth of 100 yards, and A Jortiori wben it
has exceeded it, mechanical appliances should certainly be intro-
duced for raising and lowering the men, because time and strength
«re wasted by dimbing ; besides which, medical men are agreed
that excessive ladder-ctimbing is iniurioas to the health of the
miser. Therefore npon hygienic and upon financial grounds, one
of the £ret thoughts in working a mine should be the conveyance
of the men down and up the stoft with the least possible fatigue,
by means of machinery.
Buckets and Cages. — This method of going down and com-
ing up from mines recommends itself by its simplicity, and when
carried out with modem appliances it is remarkably safe.
If the machinery is being worked by hand, the miner usually
stands with one foot in the kibble and uses the other to guide
himself, while he holds the rope in his hands ; this guiding is
specially necessary when going down an inclined winze with
rough and rugged sides. Some men prefer to have one foot in
a loop at the end of the rope, whilst others like a special stirrup.
At the ozokerite mines of Boryslaw, and also in sinking ml-
wells in Burma, special precautions are taken in case the men
should become unconsdous from breathing an atmosphere highly
charged with noxious gases. In every case the man is secured
by a second rope, so that he can be drawn up even if he falls
from the bucket. The Bor^law safety-gear is a strong leathern
waist-belt to which is attached a broad strap divided into two at
each end. One thong passes over each shoulder and is buckled
to the belt, and one under each leg is attached in a similar
manner. An iron ring between the shoulders completes the gear.
It serves for attaching the second rope, or life-line, coOed upon a
separate windlass, and paid out as fast as the main rope with the
bucket in which the man stands with one leg. Many of the
shafts worked in thb way are more than 150 yards deep, and one
has attained a depth of 363 yardi (340 metres).
Guides are compulsory In this country after a depth of 50 yards
is exceeded, unless the owner of the mine has obtained an exemp-
tion from the inspector of the district. I explained in the chapter
upon winding how they can be applied to the kibble or bucket
«ven in a sinking shaft ; but the usual method of ascent and
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531 ORE AND STONE-MINING.
deecent is by the oage, or some fona of guided box. little need be
said about the prooeu of lowering and nusiiig, for it is pntcticall^
the same as wioding miDeial. Rules are made defining the
number of men allowed to ride at one time, and generally there
ia a bar near the top of the cage which the men can hold, in case
there should he a little jerk. In some countriee it is neceeEary
that the cage should be so enclosed that there is no possibiHtj of
a man falling out during his mpid ride. As sending the men
down and up in this fashion interferes with the winding of
minerals, access to the oage should be easy ; even stooping causes
a little loss of time, and the despatch of the men into the miue
will be expedited if the cage is high enough for them to walk
in upright without any thought for their heads. If the spaice is
too low for standing up conveniently, the men may be made to
orouch down in mine-waggons, which are pushed on to the oage as
if they contained mineral.
The extent of the interference with the regular winding opera-
tions will he beet understood by examples. The Government
regulations at Mansfeld* do not allow a greater speed than 328
yards per minute (5 metres per second) when men are being
wound. At Ernst I. shaft, which is 41 1 yards {376 metres) deep,
it was reckoned, a few years ago, that seven hours out of the
twenty-four were occupied with tiie deecent and ascent of 1069
persons, thus :
Uondag from 4.30A.11. to 6.30a.h.,3 hoars ... 450
Aitemoon „ 11.30 p.m. „ 3.45P.H., 3} „ 415
BveoiDg „ 9.iSP.I(. „ ii.o P.M., ij „ ... 204
At Ernst III. shaft, which is 273 yards (150 m.) deep, the
figtires were as follows :
Homing from 5.0 A.]f. to 6.1; a.m., i^boars ... 260
AfteTDoon „ 1.15 P.M. „ 3.30 P.M., i^ „ 334
BTening „ 9.30 P.N. „ ia3o P.U., i „ ... 149
3i .. - 643
The cage at the former shaft took seven men at a time, and
that of the latter, sixteen men, as it was double-decked.
With the object of relieving the ordinary winding-f^nt from
this task in one part of the district, a new shaft was sunk solely
for raising and lowering the men.
The British law demands that, in addition to the guides already
mentioned, there should be a cover overhead, so as to protect the
men from things accidentally falling down the shaft. The use oS
HiKhien. Halle an der Stiale, iSSg, p. 73.
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DESCENT AND ASCENT. 533
A single-liiibed ch&in is forbidden, except for the short ooupUng
piece connectiiig the cs^ to the rope. There most be flangee to
prevent the rope from slipping off the drum ; the winding
m&cbine has to Be provided with an adequ&te brake and a proper
indicator ; and, lastly, there must bo means of signalling up and
-down from every landing-place in the shaft. In some oouutriee
safety catches are compulsiary.
An ingsnioua and useful method of signalling is that of Mr.
Armstrong, who inserbi an electrically insulated wire into the centre
of the winding rope for the purpose of communicating from the cage
itself to the engiueman, no matter whether the cage is in motion
or not. The electric wire is brought into contact with an insulated
metal ring placed upon the crank shaft of the engine, and a
<!opper lev^ preesing upon this ring plaoee the wire in communi-
cation with a small battery. The wire rope itself servce as a
return. The circuit can be completed by pushing a button inside
the cage, or another plaoed apon the roof, and the ringing of a
bell at the surface gives the necessary mgnals to the eugineman.
This rope, which is made by Messrs. ^ggie & Co., of Sunder-
land, is being used with success at coUieries in the north of
England, and at one of them a sepaiut« shaft is set apart for the
men, so as not to interfere at all with the winding of coal ; the
cage carries twenty men at once, and is always in d^ge of a con-
ductor, whose duties resemble those of the attendant at an hotel
lift or elevator. By merely pressing a button he signals direct to
the engineman to start or to stop as required.
At mines under the Coal Mines Act in this country, the rate
of winding men must not exceed three miles an hour after the
cage has reached a point in the shaft which is fixed by Special
Kulee. However, this r^ulation applies only in cases where the
hoisting apparatus is not provided with some automatic contriv-
ance to prevent overwinding. In Qermany a speed indicattor
has to be applied when men are being raised or lowered ; among
instruments of this class may be mentioned the tachometer of
Messrs. Schaffer and Budenberg, which indicates the rate of
winding by a pointer on a dial in full view of the engineman.
Winding by the cage is not confined to perpendicular shafts.
At 0am £b^a Mine in Cornwall a two-decked cage, holding six-
teen persons, runs in a shaft which is perpendicular for the
first 1 30 fathoms and then follows the changing dip of the lode
for 170 fathoms more. The inclination varies from about 10° to
30* from the vertical. In a shaft of this kind it is impossible to
wind with safety at speeds which are common at collieries ;
nevertheless the cage does very useful work, and as the rope is
renewed every four months, there is little chance of a breakage.
The cage at Junge hohe Birke* Mine, near Freiberg, oonsista of
* IrtibcTj/t Berg- und EiltUmcaen, 1893, p. ij6.
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534
ORE AND STONE-MINING.
five small compArtmente one Above the other, ekch fomuag', as it
were, a eepmte link of e, chain ; the cage can thus accommodate
itself to bends in the shaft. Each compartment takes two men.
JCan-engine.— The fiist man-engine was put up in the Harts
in 1S33, and nine years later a similar machine was fixed in
Tresavettn Mine in Cornwall. Sinoe that time this useful means
of conveying men up and down shafts has been resorted to in
other mining districts, such as Belgium, Westphalia, and Saxony.
Two kinds of man-engine are in use — the double-rod and the
single- rod machines.
The doublA-rod, or original man-engine, consists of two
reciprocating rods, like the main rods of pumps, carrying small
platforms upon which the men stand. The stroke
FiGB. 603, 604. is from 4 to t6 feet, and the little platforms are
arranged so that they sre always opposite each
other at the beginning and end of each stroke.
Figs. 603 and 604 represent the rods in the two
final positions. A man who winhes to go down,
steps upon platform 6 (Fig. 603), the rod B goes
down and A goes up, bo that b is brought oppo-
site c (Fig. 604). The man steps across from b
to c, the rod A makes a down stroke, and B an
upstroke. Platform e is now opposite d (Fig.
603), and the man again steps across ;
and thus, by constantly stepping Fia. 605.
from the rod as it completes ite
down-stroke, the man is gradually
conveyed to the bottom of the shaft.
By reversing the process, or, in other V ^
words, by stepping off on to the "
opposite platform as soon as the rod has completed its
up-etroke, the man is raised to the surface without any 1
fatigue beyond the very slight effort of stepping side- ^ ^
ways. If each rod makes four up and down strokee ■' *
of 10 feet each per minute, the rate of ascent or
descent will be So feet per minute.
The aingle-rod man-engine has one rod carrying
Bteps, while fixed platforms are arranged iu the
shaft BO ae to correspond exactly with them (Fig. 605).
If a man wante to go down, he steps on to A when
the up-stroke is completed; the rod goes down and V ^
the step A is brought opposite the fixed platform 6, H' '
on to which he steps off. He then waits on b until
the rod htts finished its upetroke. B is brought
opposite b, he steps on to B, the rod goes down and he is brought
opposite e, where be again steps off and waits. By revereing the
operation he is gradually lifted up to the top of the shaft. The
single-rod engine may be used by men going up while others ar»
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DESCENT AND ASCENT. 535
going down, provided that there is eoffidettt room upon the fixed
platforms (ac^Iora, Oorawall). It is best to h&ve platforms right
and left, as shown in the figure, and then the ascending men st«p
ofi* always to the left, for instance, while the descending men take
the right hand eollars. The asoandiug man steps on to the man-
engine as soon as the descending man stepa off, and bo the rod
may be always carrying men up or down. The usual stroke in
Cornwall is ii feet, and there are from 3 to € double strokes
per minute. With 5 strokes the men descend 10 fathoms a
minute, or, in other words, a descent or ascent of 300 fathoms
occupies half-an-hour. However, after the first man has reached
the bottom, the rest will be coming down at the rate of five a
minute. The reciprocating motion is best obtained from a crank
(Fig. 706), because in this case the speed is gradually diminished
at the dead points, and the danger of an accident in stopping off
and on is thereby lessened ; man-engines, however, are sometimes
driven by direct^acting engines, and, at Laxey Mine, in the Isle of
Man, a wat«r-preeBure engine furnishes the motive power for
one of these machines.
Man-engine rods are constructed of wood or iron ; and at St.
Andreasberg, in the Hartz, each rod was replaced by two wire
ropes. Like a pump rod the man-engine rod requires proper
balanc&-bobe and catches, and for the safety of the men a handle
is provided at a convenient height above each step. Sloping
boturds shoold be £xed under each platform, so as to make a
funnel-shaped passage guiding the man's head into the proper
channel, in case he is not standing upright when "riding" up.
A useful addition is a small wire rope passing down from Bollar
to sollar, and placed within easy reach of a man when standing
on a step ; he grasps this with one hand as he steps off on going
down, and steadies himself by it if necessary. When riding up,
he passes through the sollar and sees where he is going to step
before he gets off, so it ie not required on both ddes of the fixed
platform. There should be a signal line, with means of working
It, at every sollar, for enabling any miner to ring and stop the
man^ngine in case of an accident. It is well, too, to have a
ladder-road at the side of the man-engine, in order to afford a
means of going up or down in the event of some unexpected
breakdown of the machinery ; but the plan of fixing this ladder-
way between the two rods of a double engine is not to be com-
mended, for the wider the space between the rods the greater the
chance of an accident.
The man-engine has the advantage that it can be safely applied
in inclined and crooked shafts, and it is convenient in vein-mining
where the men have to work at vety many different levels.
The cost of raising and lowering men by the machine is not
great. At Dolcoath, a tin mine in Cornwall, more than 400
lath<nuB deep, it was reckoned a few years ago that i\d. per man
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536 ORE AND STONE-MINING.
per day coverad all sxpeoses, including iutereBt upon the capital
expended and depteoiatioa of plant.
Judging l^ what has taken place during the last ten Teais, it
aeems likely that the man-engine will erentoally die a nateral
death. It haa all but disappeared at Mansfeld, being replaced
by the safer and more convenient cage, and these seems litfcle
probaUlity of new machines being ereoted in Cornwall.
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CHAPTER XIII.
I. Hechanicttl TO0ce«6ea : (i) Washing Id order to separate clay, mud and
(3) Haad-plokiiig— {j) Breaking n^^ sabdiTiBion, or ahaping —
pomeiation or oonsoUdation — [5) SoreeninK or sittiiig. 11. do-
nation— (4) Csmentation or precipitation b; Iron — (j) Amalgamation.
Bxamjdes — Lobs in draulng — Samiding.
Umdbb the convenient term of "dressing" are included the
proceeses by whicli the miner prepares his mineral for sale, or by
which he extracts a marketable prodact from it. These procesaee
are vety Tatioua, and cannot all be properly comprised under the
French heading "Preparation m6camque," because, in addition to
using mechanical means, the miner often invokes the aid of heat,
magnetism, or chemical affinity, in order to separate the valuable
material, from the worthless rock with which it ia associated in
the earth. It must also be recollected that there is a borderland
between mining and metallurgy, on which both miner and smelter
may fairly ■^1"''" a footing, because the former does not always
send away his ore in the same state of elaborntion. Some may be
inclined to cut the knot by saying that the business of the miner
is at an end when the mineral is landed at the surface ; but in
actual practice this is the exception, and the person in charge of
the mine has usually to superintend certain processes which are
carried on in order to obtain a readily saleable article.
I propose in this chapj^r first to describe the various dressing
processes, and then to explain how they are applied to the
most important minerals with which the miner has to deal.
In order to have a clear idea of the principles which guide
the miner, it is requisite that we should classify the processes
which he employs; and we may at once make throe main
divisions, acccn^ng as the process is effected solely by mechanical
means, or is based upon the physical or chemical properties of the
minerals treated. This classification is somewhat arbitrary:
differences of opinion may exist, for instance, concerning solution,
some persons considering it as a chemical process, others, as a mere
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538 OBE iND STONE-MINING.
chimge (d state without any chemictil action ; again the prooeas b;
which A physical property is brought into play is usually efiected
with the aid of mediaDical applianoes; and lastly, chemical modi
physioal actions may both be involved in the method of treatment.
It must, therefore, be understood that the classification is eatab-
liahed rather for the convenience of the student, than with the
idea that the subdivisitms of the subject are strictly defined in
reality. It will be seen also as we proceed, that many of the
eub-claseee refer to exceptional processes applicable only to special
minerals.
The folloving table gives an outline of the operations employed
in dressing :
I. UaCHAiiiOAi. PaocESSBS.
I. Washing In order to wpaiate clay, mnd aod sand.
3. Hand-tncUng.
3. Breakhig np, ■nbdlriaioii, or afaaplng.
4. Agglomeration or oonaolidation.
5. ScreeniDg or sifting — v«., claMiflcatlon aooording to die.
8 DIPIKDING UPON FBTSICAL
I. Motion in water,
a. Motiim in air.
3. Desiooatlou.
4. Liquefaction and diitillation.
5. Hagoetio attraction.
6. Sepamtion according to d^ree of triability.
III. Pbocebsbs DBi'EifDiHa trPON Chemical PBOFaKrna.
I. Solution, evaporation and crTstalllsatioD.
a. Atmoapherio neatbeiing.
3. Calcination.
4. Cementation or preoipitation by Iron.
5. Amalgamation.
I. MECHAinOAI. PBO0ES8BS.
(i) WASHHTG. — The object of washing is twofold : removal
of earthy impurities, and prehminary cleansing previous to h&nd-
piddng, for the valuable mineral, as it comes from the mine^ is
often completely masked by a coating of ilirt.
The process is carried out by hand or by machinery. The
simplest appliances are the pan and the batea, which are specially
used in the case of gold and tin. The pan is a circular dish ottM
of tin-plate or stamped iron or steel, about 15 or 16 inches in
diameter at the top and 10 or 11 at the bottom, with a depth of 3
or 4 inches. After having been partly filled with the mineral to
be washed, it is held in a pool of water, or a vat, in which it can
be moved so as to impart a oircnlar motion to its contents. By
suitably inclining the edge, the muddy stream is made to flow c^
more clean water is taken on, and the process is repeated until there
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DElSSINa. 539
remains nothing butwell-washed saod and gravel inthe bottom. The
big Btone6 are taken out and examined, ood thrown away if worth-
leas ; large nuggets, if present, are now visible and can be picked
out, whUst the sm^ Btonea and Band are again mixed with water
and washed, bo that the lighter particles flow over the edge and the
heavy onee remain in the pan. By careful manipulation the
water Is made to run repeatedly over the residue, and separate the
various ingredients according to their specific gravities, as will be
explained later. The pan, therefore, acta not only as a washer, but
also as a concentrator.
Though the main use of the pan is for prospecting, it must be
remembered that very Urge qnantities of alluvial gold have been
extracted by its aid.
The batea fulfils the same purpoee as the pan. It is usually
a shallow conical bowl made of wood, stamped sheet iron,
hammered copper, or spun aluminium or copper. Convenient
dimensions are: diameter i8 to so inches and depth li to 3
inches. In some parts of India the wooden gold-wasbing dish is
rectangular. The mineral is treated much in the same way as in the
pan, but the batea has the great advantage of bringing all the
heaviest particles to a point, ioetead of an edge. Sluch gold has
been obtained with thia primitive appliance, especially in ^uth
America and Central America, whilst in the Malay Peninsula
it is used for extracting tin ore from gravel, and in SrazJl
for washing out diamonds. In prospectant the batea is in-
valiiable.
If la^e quantitiesof mineral have to be handled, it is necessary
to separate the adherent dirt tn Bome cheaper fashion. Occupying
an intermediate position between the hand-bowls and the rotary
machines are simple washing pits of difierent descriptions.
Some of the lead ore of North Wales occurs in the form of solid
lumps of galena enveloped in clay. The ore coming from the
mine is thrown into a stone-lined pit about 18 inches deep, partly
filled with water, in which it is pushed backwards and forwards
until the galena is separated from its clayey matrix. This kind of
washing pit is known as a "jobbing buddle."
Fhosphatic nodules are cleansed from sand in a similar manner,
by being raked or shovelled backwards and forwards in long
wooden troughs full of water.
The Australian paddling maohine is an example of an
appliance for doing similar work by the aid of a horse or other
available power. It is a circular pit in which gold-bearing gravel
ia stirred up with water by knives attached to radial arms, which
are carried round by a vertical axis.
The rotary washing maohine employed at the diamond mines
(Fig. €06) is identical in principle. The object is to free the
weathered " blue ground " from the finest sand and mud and leave a
clean gravel in which the diamonds shall be distinctly visible. The
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540
ORE AND STONE-MINING.
rotuy washer is an annnlar iron pan A (£1g. 606) 8 to 1 5 feet in
diametOT and iti inches to 2 feet deep externally, whilst t^e inner
rim, B, 4 feet in diameter, is only 6 inches deep. In the centn
is a rendying vertical shaft, G, oanying 8 or 10 radial arms,
D, each provided with 6 or 7 verlioal bladee which dip into the
mud and gravel, and stir it up as they revolve. At De Beers
mine the washers are usoally 14 feet in diameter, ^e stuff is
fed in at the outer drcomference by a shoot coming from a
screen, and the muddy water escapee over the low inner rim of
the pan. The teeth or stining kmves are arranged so as to bring
Fio. £06.
DUIMETHt* >B
.f .
the heavy gravel towards the outer orcumference. As a pre-
caution, the muddy water flowing out of the washer is run into
a eimilar machine, and is again stirred up so as to catch any
diamonds which may by ohanoa have escaped iu the first operation.
When the pan has been at work for twelve hours, a sliding door
is pulled out at the bottom, through which the gravel falls into a
truck underneath, as it is drawn round by scrapers attached to
the aims.
Another form of mechanical washer* (Fig. 607) is a revolving
sheet iron drum, made in the form of a truncated cone revolving
upon a horizontal axis, and provided with internal stirring blades,
llie " stuff " to be wadied is fed in at the centre of the ^lall end
* Unkenbach, Pie Ai^TiatUung dtr Eree, Berlin, 1887, plate II.
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DRESSING. 541
with a stream of water. In Pig. 607, a in the drum, b the conical
mouth, oc the arms which attach the drum to the central shaft d ;
ee are teeth, y the shoot from a hopper, p' a pipe bringing water, the
amount of which can be regulated by & co(^. The greater part of
this particular drum is perforated, and it acts as a dsing machine
after having done the washing ; m is the driving puU^, h an iron
trough catching the discharge of the sieve, and i a small trongh
whid^ takes the stones discarded by the sieve.
This machine is intended for washing small stuff (" smalls ")
previous to picking. The washing of the larger lumps is often
effected by turning a stream of water upon them over a coarse
iron grating.
Fio. 607.
H
(2) HAND-PICKIirG. — No process is simpler in principle, it is
merely the separation by band into classes of varying quality and
richness ; the difQculty in practice is to know how tax it ^uld
be carried, before the min^^ is treated by machinery.
In many cases hand-picbing may begin underground, and
where worthless rock can be so separated without difficulty,
it should be removed with care, so as to avoid useless ex-
penditure for tramming, hoisting and dressing. If a mineral
is specially valuable, it is often worth while picking it out and
sending it up by itself, with a view to preventing loss or theft in
transit, or loss in dressing due to the admixture of a large pro-
portion of refuse. Picking of this kind is resorted to in working
rich pockets of gold or silver oi« under the superintendence of a
foreman. Pieces of pure ozokerite are picked out by the
Boryslaw miners and aent to the surface in sacks, and the men
are stimulated to do the work as thoroughly as possible t^ a
premium paid for the clean lumps.
By the dim light of a candle the picking process cannot, as a
rule, becarriedfnrther than the separation of worthlessrook,and,
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543 ORE AND STONE-MININO.
occMionally, the selection of some very rich pieces of minenil ; nor,
if the light were better, would it be advisable to do more, for the
anderground tniffic would be complicated if a numberof classes of
mineral were made, and the work c^ picking can be better per-
formed hj keen-eyed boys and girls at the surface th&n by the
minen underground, especially after they have passed middle age.
Picking IH generally carried on after the mineral hae been
subjected to a washing process of some kind. The washed
mioeral is spread out on a table, and boys and girls, standing hy
the side, separete the stones that lie before them according to their
richness and the subsequent processes they will have to undergo.
A scraper made of a piece of iron, bent as shown by
Fig. 608. Fig. 608, aseistG them in drawing the lumps towards
^—^ them or into a box, waggon, or barrow by the side of
A the table.
J In a lead-mine we may have (n) clean galena ; (fc)
/ mixed ore, i.e., pieces constating partly of galena and
jl partly of barren veinstone ; (c) barren veinstone and
n pieces of the surrounding rocks (country). This is a
H moat simple case ; but very frequently one has to deal
H with a deposit producing the ores of two or three
H metals, especially in the case of lead and zinc, and
<■ then the classification into various qnalitiee becomes
O more complicated.
Where the amount of mineral to be picked is con-
siderable, labour roay bo economised by eelf-disoharging tAblea,
of which there are two kinds — revolving round tables and tm-
velling-belte.
With the former the mineral is fed on at some point of the
circumference and the picking is done by b<^ or girls standing
around. They select pieces of certain qualities and richness as
the table revolves in front of them, and finally, when a revolu-
tion ifi all but completed, nothing remains on the table but mineral
of one quality, which is swept into a box or waggon by a fixed
projecting scraper.
Endless belts are made of hemp, wire-gauze^ or steel plates
attached to endless chains, and they are aometimeB as much as
4 feet wide. The refuse is picked off as the mineral travels by,
and the dean product can at once be delivered into railway
wagons, ready for despatch to smelting works or to some further
process of dressing.
(3) BBEAEZKa TTP, SUBDIVTSIOIIT, OB SEAPnrO.
— Reduction in sise is necessary for various reasons. Even when
an ore is clean enough for the smelter, the large lumps are
often crushed by the miner for the sake of obtaining a fair sample
of the whole, or of supplying a product which is at once fit for
the furnace. Fertilisers, cements and pigments have to be fijiely
ground before they can be used, and tha grinding may or may
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DRESSING. 543
not take place at the mine. The chief object of breaking up,
however, is to set free the particles of ore, which are generally
found endoeed in or adhering to particles of barren yeinetone.
Few prooeaaes in dressing are of more importance than the
proper breaking up of the ore or other mineral. A very large
number of machines are employed suitable for the different
Bubetanoee which have to be treated, and it will be impossible
Fio. 609.
witliin the limits of this chapter to do more than pass the most
important in review in a somewhat summary manner.
The breaking may be done hy hand or by machinery.
'\The processes of breaking by hand may be divided, according to
the precise object in view, into :
a. Breaking with the aledge hammer iragging and tpalUtig].
h. OobUng.
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544 ORE AND STONE-MINING.
a. Breaking with the Sledge Hammer. — lite term
" ragging " is applied, in Cornwall (Fig. 609)*, to the process of
bret^ng up the veiy big lumps (roett) as they come from th*
mine by a large sledge hammer weighing about 10 or 12 lbs. 1^
7l0.6ia
work is done by men, who, in addition to breakiDg the lamps,
may separate the broken pieces into various categories acoorduig
to quality.
Spoiling is work of a similar nature, but performed with a
smaller sledge, weighing 4 or 5 lbs., which in Contwall can be
wielded by a woman {Fig. 610). Sometimes there is a littJe
Fio. 611.
picking at the same time. The process of spalling is often a
preliminary to crushing by stamps or rolls.
b. Cobbing. — Cobbing is a special kind of breaking with a
small hammer, in which the blow is directed with the object of
knocking ofi* a piece of poor rock from a lump of minced ore and
refuse. The work is usually performed by women {Pig. 5ii),
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girls, or boya, who commoDly sit down and strike the lumps upon
an anvil of some kind, often aa old stamp-head. As the lumps
are held in position by the left band, a badly directed blow may
Fio. 613.
cause a nasty wound ; to prevent injuries of this kind, the girls
formerly employed in cobbing copper ore, at the Mona and Parys
mines in Anglesey, wore pieces of iron around their fingers, and
short pieces of india-rubber tube are used for the same purpose.
e. Bucking.- — Bucking is breaking with
a very broad flat hammer in order to reduce
an ore to coarse powder. The hammer, called
a " bucking-iron," is about 4 inches square
with a steel face ; thehandleisfrom 18 inches
to 3 feet long. The ore is struck upon a thick
flat plate of iron {Fig. 6ia).
d. Splitting.— Splitting is required with
slate, and also with stone which will rend
along certain directions other than cleavage
planes, such as planes of bedding. It is done
with a wedge of some kind, increasing in
Bh&rpneSB with the thinnees of the slice re-
quired. Blocks of slate are split by the
Welsh quarrymen with a stout wedge into
slabs about 3 inches thick, and the process
is then repeated with a thin one (" cyn d
bollti") (Fig. 613} until they
more than ^ or ^ mch thick.
obtain a roofing material often not
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546 ORE A2HD 8T0NE-MINIHO.
e. Trimmisg. — Trimming into sbape ia necessary with many
kinds of stone. Thus the Bath freestone is reeawa by hand at
the surface (Fig. 156), if the blocks are not quite suitable for the
market as they come from the mine. The hearthstone raised at
Qodstone in Surrey is hewn into neat blocks by a peculiar double-
headed axe, whilst paving- stooes, chert, and gun-flints are
fashioned with the hammer; roofing-slate is chopped into rect-
angular pieces with a lai^ knife.
Many of these hand-prooesses are gradually disappearing,
owing to the introduction of machinery which will perform the
work with a saving of time and labour.
Machines for breaking up, subdividing, or shaping oren and stone
may be classed as follows :
a. Breakers with leciprocatlDg Jaws.
b. Stamps.
e. Roll*.
d. Hilli.
e. Bdn-nmnan.
/. BaU-gricders.
a. DUiDt^iaton.
A. Conical Krindera and breaken.
i. CentTifnml grinders.
j. Fnenmatlo polveritert.
k. Mlsoellaoeoas pnlverlMn.
I, Sawing naohlnes.
(a, Pluiing machines.
VI. fllatflttisklng machines.
a. jRW-breakers. — These machines, often called rock-hreakers
and stone-breakers, crack stones \ty the near approach to one
another of two powerful iron or steel jaws. The best known
stone-breaker is the machine invented by Blake, which has
rendered inestimable services to the miner for the last thirty
years, and the introduction of which constituted a most important
step in advance in the art of ore-dressing. Its mode of action is
very simple. When theshaft A(Fig. 614) revolves, an eccentric
raises the pitman B, and by means of tfae toggle-plates C O causes
the movable jaw D to approach the fixed jaw £, aud so crack any
stonaa lying between them. During the descent of the pitman the
jaw D is drawn back by an india-rubber spring. The jaws are
tisuaJIy toothed, the ridges of one jaw being opposite the grooves of
the other when the machine is employed for breaking stones at
mines; if the object is to make road-metal, the two sets of ridges
sre brought opposite each other. The wearing parts of the two
jaws £ £ and D D are replaceable, and if these castings cannot be
immediately obtained in a distant country, it is possible to do
good work with flat platee of steel.
The stone-breaker used at mines commonly has the renewable
port of each jaw made of one casting instead of two as represented
in the figure. The distance between the two jaws, and conse-
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DEESSING. 547
qnently the fineness of the product, can be regulated by raisitig
or lowering the wedge-piece on the right-hand side of the figure,
or by inserting other toggle-plates.
The Bkke rock-breaker, with the improTements introduced by
Marsden, is made in various fiizes, so as to take stones as large as
34 inches by iS inches; the smallest machine is lo inches by 8
inches in the mouth.
Various similar machines are in the market. Baxter claims that
he produces fewer small chips and less dust — matters of import-
ance ia making road-metal — by hie so-oalled " knapping-motion."
Marsden has a breaker with what he calls a " lever motion," in
which the togg1e-plat« moving the jaw forwards is impelled by a
FiQ. 614.
bent lever worked by crank. Hall has two movable jaws placed
side by side which act alternately ; as all the parts are balanced,
lees power ia said to be required to drive it. Lester's machine is
verr simple, as the moving jaw is driven directly by the pitman
without the intervention of any toggle-plates.
For crushing to finer sizes, Marsden has an ingenious pulveriser.
It resembles his stone-breaker by having two jaws, one fixed and
the other movable, but the moving jaw bss a rubbing as well as a
squeezing action. The machine is supplied with a sieve, so that
any part of the product not fine enough for use is returned
automatically so as to be recrushed.
The Dodge crusher {Fig. 615*) differs from those just described
* Cki[ded br penniMion from a paper by Ur. A. B. CDitia, which maj be
eotaattei with adraiitagcby those who deri"" '"* " " — ■-'---
_. ,_ , -aSednC "
Mper,
Ida: "Qold-qnaTti Bednction, iVoe. JruC. C. £., vol. cnii., 1891-02,
I^uther details are eiTen bj FrofessoT Egle«toii In hie otefnl
"California BUanplSSia,'' Enffiiieervig,JoL x]L, 1880, pp. ig, 85,
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548 ORE AND STONE-MINIKU.
in h&ving the moving jaw pivoted below, instead of above.
Consequently the effect of the stroke is fdt rooet at the top.
One object of this arrangement is to obtain a more ouiform
product than is possible with a constantly varying discharge orifice,
Hke that of the Blake breaker.
Fro. 615.
THE DOOSe CRUSHER.
b. Stamps. — Though used at roinee for several centnriea,
stamps still hold their own in spite of many competing forms of
crushing machinery. The simplest mode of describing stamps
is to say that they are pestles worked by machinery in large mortars.
In most instances the blow of the pestle is caused by its mere
weight, sometimes a spring is added, and occasionally the action of
gravity is aided by compressed air, or by steam pressure. We
thus have four kinds of stamps ;
a. GraTitation Btamps.
p. Stamps with apiing.
y, CompreBsed air Btampg.
h. Steam-bammer stampi.
A little study of the accompanying figures (616-620*) will
^plain the most impcoi&nt cbaracteristice of a modem stamp-
battery.
a. A A(Fig. 616) are blocks of timber forming the solid founda-
tion, which is required on account of the heavy pounding action of
the machinery ; B B, the transverse siUs, with the battery-posts
0 C, the bracee £ and the tie-timbers D D form the framework
holding the mortar or battery-box {ko/er, Cornwall) F, in which
the mmeral is pounded by any one of the five stamps moving
up and down in it, G is a perforated plate or screen which pre-
vents the mineral from leaving the mortar until it has been
brought down to the required degree of fineness. H is the shaft
carrying cams, which lift the stems by tappets ; K K are the
ends of the stems or lifters of the stamps proper; L is the
pulley through which motion is transmitted to the cam shaft l^
* Curtis, Op. eit.
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Uie belt apon the driving pulley M. N it
which the driving belt tan be tightened.
the gear by means of
Each stamp proper, K K, consists of a turned rod of iron with
tapering ends, either of which will fit into a corresponding hole
in a cast-inm cylinder known as the " head" (Figs. 617 and 630).
Fio. 620,
Fra. 61?. Fia. 61S. Fio. 619.
The conical hole or socket in the bottom of the head receives the
shank of the " shoe," which is made of cast-iron, cast-steel, oi-
foiled steel. "When worn the shoe can be removed fnan the head
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550 ORE AND STONE-MINmO.
by driving a steel key into a slot above it (Fig. 610), and the stem
or lifter is extracted in a similar manner by means of a Becond
slot at right angles to the £r8t.
The mortar is shown on a larger scale in Fig. 617. It is ■
cast-iron box with an opening £ at the hack for feeding, and (me
in front, into which is wedged the frame F of the screen. Some-
times there is a screen behind as well as one in front, or mx^eaa
at both ends as well as at the two sides.
Fig. 618 represents the tappet, a hollow cylinder of cast-iron,
which is fastened to the lifter by steel keys and a gib. The gib is
a piece of wrought-iron fitting the
FiQ. 63 1 . curved surface of ^e lifter and capable
of being jammed against it ti^tly
when Bteel keys are driven into three
holes in the tappet. As the abaft H
'i revolves, the cams (Fig. 619) lift t^e
• tappets, and at the same time cause a
-.1... slight rotation of the stamp, whidi
.^ conduces to regular and even wear.
» The head B, with its shoe 0 (Fig.
"'" ^17)1 drops upon a cylinder of aimiUr
metal known as the die, and it is be-
tween C and D that the mineral is
patverised. Both shoe and die wear
away and have to be changed from
time to time. The worn shoe and die
represented in Fig. 63 1 were reckoned
to have stamped 150 tons of gold
qnartE at the Morgan mine, North
Wales, before they were given up;
they were made of Fraaer and Ohal-
mere' forged steel. The order in
which the heads drop is not invariable;
the object of any arrangement is to
make each head do its fair share of
work. Egleeton mentions six different orders of dropping whic^
are in use, and this shows how much opinions are divided on tlie
subject. Among them may he mentioned 3, 4, 5, 2, i, and i,
5. a, 4, 3-
The screens through which the pulverised mineral has to pass
are made of punched iron, steel, or copper platee, and occamonally
of wire gause. The holes are round, or in tiio form of long narrow
slots. The size of the holes ia better expressed by their actual
dimension than by their number per linear inch or centimetre.
The total weight of each stamp when new, that is to say stem,
head and shoe, varies from 500 to 950 lbs. ; weighte of 700 to
800 lbs. are common. The precise height and number of the drops
are further points requiring consideration; the height varies
'i
„• 1
1
..
i
i
«*A.
■j
f
r,-* "ia
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DRESSING. 551
generally from 8 to 11 inches, and there are 70 to loo drops
per nunute. Ore may be stamped dry or wet ; in the latter case,
water constantly flowing into the mortar-box carries off the
mineral through the screens in the form of a muddy stream
known as " pulp." Eglestoa reckons that the quantity of water
used in wet stamping is from j to ^ cubic foot per stamp per
minute, or 200 to 300 cubic feet per ton of rock stamped.
The quantity stamped per head per day must nec^sarily vary
within very wide limits, according to the weight of the stamps,
the nature of the stone treated, and the decree of fineness desired.
Speaking roughly, it may be said that each head will stamp a tons
per 24 hours and require 2 h,-p.
Aegular feeding is of much importance, and severs! automatic
arrangements can be applied to the battery for securing the
desired result. Most frequently a tappet upon one of the stems
comes into play when the stomp has a longer drop than usual,
owing to want of ore under it, and strikes a lever which brings
the ore-feeding contrivance into action,
j9. Spring stamps are but little used. Patterson's " Elephant "
stamps belong to this class : the object of the inventor was to secure
a stronger and quicker blow than would be given by a mere fall,
and BO enable a small machine to do more work than would be
possible if gravitation were acting alone. The stamp is worked
by a ciunk, and interposed between the striking head and the
connecting rod there is a strong spring, which assists by its reooU
and allows for the varying height of the ore in the battery-box.
y. Husband's pneumatic stamps were designed with the same
intention — viz., a quicker and a harder blow. The stem or lifter of
the stamp is attached to a piston workiDg in a cylinder which is
lifted rapidly up and down by a crank. There are holes in the
cylinder which allow the air to escape during the middle of the
stroke, but after it has been raised beyond a certain point,
the air below the piston becomes compressed and the stamp is
lifted. The cylinder in its downward course travels quicker than
the stamp would fall, and compressing the air above the piston
helps to drive it down and with it the stamp ; it thus increases
the force of the blows, which can be given at the rate of 140 per
minute. Though good results have been obtained in some cases,
these stamps have not made their way into general use, for mining
engineers seem to consider that the simplicity of the ordinal?
stamps, and the ease with which any slight defects can be repairecl,
make up for the disadvantages which Husband tried to remedy.
3. We now, lastly, come to the steam-hammer stamp, which has
proved a most efficient machine at the Lake Superior mines for
the treatment of rock containing native copper. The finC
stamps of this kind were constructed by Ball in 1856 ; since then
great improvements have been made, and the present Leavitt
stamp wUl crush 250 tons of copper-bearing rock in 24 hours.
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S5» ORE AND BTONE-MININa
The Ban* stamp (Fig. 633) consistB of a vertical BtcKin-cyluideT,
C, with the stampttig head attached to the piston-rod. The
TuioQB parts an designated as follows : — D, cast-iron die ; £,
cast-iron shoe ; F, frame of mortar ; 6 0, grates of poncfaed
sheet steel; H H, cast-iron head posts; I^ cast-iron sills or
girders; M, cast-iron mortar; F, pulley by which the vsIts is
driven ; R R, cross sills ; S, shoot supplying the ore ; T T, spring
timbers ; U, " um " or cistern supplying water ; V V, cast-iron
lining plat^ resting upon a cast-iron ring surrounding the die ;
Y, pulley by which the stamp is rotated.
The dide-valve is worked from the pulley F by the elliptical
spnr-icheels indicated by the dotted tines ; the valve is opened
fully tor making the down-stroke, and the pressure of the steam
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DEESSIKG, SS3
grefttly mcreases the blow due to gravity, but for making the
up-Btroke the steam is admitted stuirpl;, and in just sufficient
quantity to lift the head.
The peculiarity of the Leavitt * stamp lies in the differential
steam-cylinder (Pig. 633). There are two cylinders, one above
the other : a large one A with a piston B, above a small one C
with a piston D. Steam is admitted on to the top of piston
B through the valve at E, and is exhausted through a valve at
F into the condenser. The space under the piston D in the
cylinder C as well as the annular space G
is filled with steam admitted through the Fio. fii3.
opening H, and kept by a regulator at a
uniform pressure sufficient to raise the
stamp. The stamp is thus lifted by the
lowerpiston,andisforced down by the large
npper one against the constant pressure
exerted by the lower. The valves regu-
lating the admission of the steam and the
exhaust valves are worked by cams upon a
shaft driven by a belt from some independ-
ent source of power. The cams which
open the steam and close the exhaust valves
are fixed, but the cams which close the
admission of steam and open the exhaust
can be adjusted at pleasure.
The moving pai-ts of each Leavitt stamp
at the Calumet and Hecla mine weigh about
5000 lbs., and the blow is struck with a
velocity of 30 to 23 feet per second. The
numbw of blows is 98 per minute; the screens aremade of the
best steel ^'^ inch thick, punched with round holes ^^ inch in
diameter, and speaking roughly about 10 tons of rock an hour
are stamped fine enough to pass through them, and are carried
away by wat«r to the concentrating machinery.
o. Bolls. — Bolls were introduced into the West of England in
the early part of the present century to replace bucking by hand.
They ore a pair of smooth, fluted, or toothed (flinders, made of
cast-iron or steel, which revolve in opposite directions, and crush
any stone which is allowed to fall between them.
The cylinders or rolls are generally from i foot to 3 feet in
diameter, and i foot to 3 feet wide ; they are kept pressed
together by levers or springs. Tor crushing metallic ores, the
diameter of the roll is generally from two to three times its
width.
llie original form of crushing rolls, and one still lai^ly used
* F. Q. Coggii%, "Notes 00 the Steam Stamp,'' Engrneering, voL xU.,
1886, pp. 119, 130, 200.
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554
OfiE A^D STOHB-MININQ,
in this country, U represented in Fig. 634, in which the lebtm
h&ve the foUovnng meanings : O, hopper, into which the ore is
shovelled from the floor, H H ; A B, the two cjlindera or rolls
shown on a larger sc&Ie in fig. 635. The roll B has plummer
blocks which can slide aloug a bed-plate, and so allow the opening
between it and the roll A to be increased or diminished ; C is >
bent lever, to one end of which is attached a weighted box, whila
the other constantly presses a [nn against the ploinmer-Uod
of B; the crushed rock after leaving the rolls falls into »
revolving cylindrical »eve. All that fails to pass through tba
sieve drops into the "rafl-wheel " £, which ht48 buckets on the
Fig. 624.
face tui-ned towards the crusher; these carry up the oo«r«e
fragments as the wheel revolves and tip them on to a sloping
apron F, whence they fall again into the hopper G to undergo a
further crushing,*
One end of the shaft of the roll A is coupled to the nuun driving
shaft of the machine, which carries the raff-wheel ; the other end
has a cog-wheel whit^ gears into a similar one on the shaft of B,
and BO drives it. The inclined sieve is driven from the shaft
of A by means of bevel gearing.
An improved form of the Cornish rolls has been introduced by
£rom,t and is meeting with approval. His improvements are:
p. i,l3-
t Erom, " ImprovementB in Ore-oraahing H*ohluerf ," ZVoiu. ^
M. E., vol. xiv., i88s, p. 497.
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DRBSBING.
555
Stoel tires, pulley gearing, houBing
to enclose the rollers, swinging
pillow-blocks, tie-bolts to take the
cnialiiiig strain, hopper for auto-
matically ensuring a regular feed.
The tires (Fig. 626) are made of
mild forged ste^,* and are held by
two cores in the form of truncated
cones. One of the cores is shrunk
firmly on to the main shaft, the
other is split on one side, but when
drawn in towards its fellow by
bolts, it gripe the shaft very tightly,
and at the same time fastens the ^ ^ , ^ ^ -~ ^
tire securely. The main shaft (Fig. '"I^-^-, ^ — ^ — j. — ,4^
6a'j)f is driven by a pulley, indi-
cated by the dotted line, revolving at the rate of 80 to 100 tinMS
Fio. 617.
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ORB AND 8TONE-MU7IKO.
ft minute ; th« other ahaf t is drivea ftt the Bune speed, but in the
opponte direction, hy orcwBing the driviiig belt of the amftller
pulley, He beuing of the shaft of the movkble roll is cuxied
ay a swinging pillow-block pivoted underneath, and oonatantly
dnwD towftrds the other roll by the stroog spiiiil Bprings. The
upper part of the figure represents the bottom of the hopper
wiudisnp[diesthero]L,uidtheoecdllatiiig feed-tray, set in mation
t^ an exoentric.
Actual experience extended over a ccoiBiderable time has proved
that a pair (» Krom rolla at the Bertrand Mill, in Nevada, will
crush 150 tons cf qnartzose silver ore in 34 hours, so aa to
pass through a screen with 16 holes to the linear inch. It
IB claimed that less fine dust is produced with these rolls than
with stamps, a matter of importance, owing to the losses in dresG-
ingor lixivia tion 'when there is a large proportion of slima
Fluted rolls are used in crushing rock-salt, and toothed rolls
•re used for breaking comparatively soft minerals such as rock-
salt or gypsum, and even luird stone for road-metal. Some of the
rolls for rock-salt are made of toothed rings threaded upon a
shaft, and the two rolls are arranged so that the teeth of one lie
between those of the other.
d. Hills. — The t«rm "mill" has a very vague eignifcation
among miners ; all sorts of machines emfdoyed in crushing and
grinding are commonly known as mills. I propose to restrict the
term to grindon, in which the working part« consist of flat or
approximately flat surfaces, one of which revolves. They are
called into requisition for reducing a mineral to a fine state of
division.
The typical mill of this class is the well-known flour mill, made
of two horisontal cylindrical stones, one fixed, the other revcdving ;
sometimes it is the lower stone that is fixed, sometimes the upper.
Mills of this kind serve to grind barytee and fertilisers. The
stonea are generally the French burr, and have to be dressed
from time to time as they wear. The mineral is fed in at the
centre, and is discharged at the circumferenoe. Instead of one
top stone, there may be several separate pieces ; this combina-
tion forms the " arraatra " employed for grinding and amalgama-
tion.
When the mill is made of iron, with iron or steel replaceable
wearing parte, it is generally called a " pan " ; like the arrastra, it
serves for fine grinding and amalgamating.
Millstones need not necessarily be arranged horizontally ; the
first grinding of phosphate of lime is sometimes done by stones
set vertically, the moving stone being fixed upon a horisontal
e. Edge-nmners. — The edge-runner is a cylinder turning upon
a horizontal axis which is made to revolve around a vertical axis.
In its simplest form, it is a large stone wheel, the horizontal axis
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DBESSINQ.
557
of wbich is drawn round an upright post by a inula Tho stone
criuhes by its weight, and as it has to slide a little in order to
keep its circular path upon the bed, there is also a rubbing
action. This primitive form of edge-runner, known as the Chilian
mill, is employed in crushing and amalgamating gold and silver
ores. It IB better to have two of the upright wheels at opposite
ends of the horizontal axis, as then the machine will work more
smoothly (Fig. 638). Each wheel is made of a strong tire of
chilled cast-iron wedged to a centre-piece of ordinary cast-iron,
and the bed is composed of sectors of chilled cast-iron, which can
be changed when they ai-e worn. The driving gear may be above
or below.
/. BaU-grlndSTB. — In machines of this class the mineral is
pulverised by its contact with a number of cast-iron balls, which
are constantly rolling against each other when the case containing
them reT<dvee.
Jordan's Centrifugal Qrinder and Amalgamator is a circolar
pan set upon an incUned axis with a few large iron balls like
cannon-balls which lie in the lowest part ; the machine is supplied
with crushed ore, which is soon ground fine and escapes through
a sieve placed around the outside of the pan.
The ingenious " Grusonwerk " ball-grinder (Figs. 639 and 630),
now made by Krupp, has a continuous feed and discharge. It con-
sists of a honzontal iron cylinder provided with several carved plates
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5S8 ORE AND 8T0NB-MTNING.
a a, which carry a ntunber of steel b&lls. The stuff which is fed in by
the hopper A falls among the balls and is ground by their nibbiDf.
During each ravolution of the drum, th»7 drop five times as th^
oome to the edges of the plates. The ground mineral pasn»
through holes in the curved plates a a, and in the cylindrical mK
e made of punched steel plate ; it now meets with the fine wire
gauze sieve d, which lets through all that is sufficiently pulverised
into the hopper «, whence it can be drawn off at pleasure. The
object of the punched steel sieve e is to prevent the unnecesan'
wear of the fine wire gauze, which would naturaJly suffer if it
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DRESSING. 559
were ezpoeed to the rubbing of coarse perticlea. The stuff which
is too coarse to pass through the fine outer sieve d is collected by
plates / and led back Into the inside of the drum, where it is
again exposed to the grinding action of the balls ; 6 6 are lining
Slates to prevent the wear of the ends of the cylinder ; 1 1 and •
enote bars closing a manhole which can be opened after the
removal of the sheet-iron casing aurroanding the whole machine,
g, DiflintegrstorB. — Though any reduction of a mineral into
fragments or powder may be spoken of as " disintegration," the
wonl disintegrator has been appropriated by the grinders which
do their work with revolving bars or beatera. The best-known
machine of thia class is Carr's disintegrator (Fig. 631). It
Fio. 631.
may be described as consisting of two cylindrical cages, revolving
one inside the other in opposite directions. Each cage is made up
of two concentric sets of bars, attached to a disc on one side and
to a ring on the other. The stuff which is fed into the centre is
thrown by the bars a a of the cage X, against the bars & 6 of the
cage T; l^ence it flies against the outer circle of barsocof X,and
finally against the outer circle of bars d of the cage Y. It thea
enters the circumferential space e, whence it can be allowed to-
eecape by a suitable opening in the outer casing _^.
It is claimed for this machine that some of the pulverising is
done by the impact of the particles one against the other, and that
consequently the wear of the steel bars is less than might be
expected. However, the disintegrator is found most fitted for
comparatively soft materials, such as coal, gypsum, phosphates,
and rock-salt.
Instead of bttDg arranged in the form of concentric cirolee in
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56o ORE AND STONB-MINING.
tliis cage-like manner, the beaten &re Bometimes raduJ, and, when
revolving at a very high speed, quickly redooe soft minerals to
powder.
A. Gonloal Orindera. — In these grinders the onuhing action
is luuallj produced by the revolution of a toothed cone,
inmde a toothed cup; they thus resemble in principle the old-
fashioned coffee- mill. The Oatescrueher (Pitf.633)acts difCerantly.
It consistA of an outer conical shell Q (Fig. 6^1), lined with
removable platen E, around which travola the coiw^ breaking
no. 632.
head F carried by the upright spindle G ; both £ and F are made
of chilled cast-iron. I'be lower end of the spindle O fits loosely
in the excentric box D, and \a a little out of the centre; it is
supported by the step F, which can be raised or lowered by the
screw S, in order to regulate the distance between the breaking
head and the shell, and consequently the fineness of the crushed
product. The upper end of the spindle G lies loosely in a socket
in the top foaming C. The belt-pulley T U is loose upon the
shaft X, and it drives it by means of the clutch Y, firmly keyed
to X, and the pin W. In case of any undue strain, the pin W
breaks and prevents damage, for the machine at once stops until
the obstruction is removed and a new pin has been inserted.
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DBE8SING. 56 1
The bevel pioion upon X drives the bevel wheel L with its
excentric box ; when L tevolyee, the lower end of Q is carried
round excentrically, whilst the top moves in its socket. The
breakiDg he&d is thus made to approach aad recede from each
part of the shell In succession, producing practically the same
effect as the reciprocating jaw of the Blake machine. The loose
collar I serves to keep out du£t, and it has a bole J, through which
the machine ia oiled ; N N are holes for conveying oil to the
space Y. The material to be crushed is fed in through three
large openings in the top frjune ; it falls between E and F, is
no. 633-
crushed by the movement of the breaking head and drops through
at Q Q on to an inclined apron, whence it slides into any con-
venient bin or reeeptacle.
i. Centrifagftl GrinderB. — There are several grinding
machines in which a roller is whirled round upon the inside of a
cylinder against which it presses by oentnfugal force. The
machine of this class most largely employed is the Huntington
mill (Figs. 633 and 634). A vertical shaft O, driven by bevel
gearing from below, carries a horizontal frame, which supports
four grinding rollers by the yokes Y Y lying in the pockets P.
The yoke allows a radial swing of the crushing roUer against the
steel ring (Fig. 634) lining the pan in which the grinding takes
place. The construction of Paxman's improved roller is shown by
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552 ORE AND STONE-MINING.
f^^uTM 635 to 637. R is K steel ring which doee the tttal
grmding and is renewable when worn; it is fixed I17 mmdn
F10.634.
wedges W to the otare G, &nd a sleere bolted on to the core recavn i
the spindle S. iVom this explanation it will be seen thit I
Via. 63s. Tin. 6j6. Fio. 637- I
SCAUC
to DECIMETKES
the ToUer cau revolve round the spindle S, bnt that the ]attfX
does not turn upon its own axis when it is carried round \>j the
revolving frame supporting the yokes. A, B, C, D (Fig. 633) are
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DRESSING. 563
wooden iicrapers which force the ore from the centre to the
circumference and so bring it under the action of the rollers. It
is easy to uuderatand, therefore, that when the shaft G revolves
the rollers are thrown out by centrifugal force against the
Annular lining, and crush and amalgamate the ore. The stuff
vhich is pnlverised sufficiently fine escapes through a wire-gauze
sieve placed on the side of the pan, just above the lining ring. As
this sieve has not to resist the violent blows to wiiich the
screens of stamps are liable, it may be made of much finer
material.
j. Fnaanuttio or Air-ourrent PalTerisdrs. — In one of
these pulverisers, it is proposed to crush the mineral by driving
the particles violently against each other by means of two power-
ful opposite jets of air or superheated steam. To use a familiar
Ulustration, it may be said that stone bullets are fired from
air-guns against each other with such force that they break
into powder upon meeting.*
The Cyclone Pulveriser, which excited a good deal of interest
at the Paris Exhibition of 1889, is based upon the same
idea. It consists of two beaters, something like screw-propellers,
-driven at a speed of 1000 to 3000 revolutions per minute
in opposite directions in a small oast-iron chamber or case, in
the form of two truncated cones joined together at their larger
bases. The material to be crushed is delivered re^larly into
this case by mechanical feeders, and the whirlwind created
by the beaters hurls the particles against each other with
such violence that they are almost instantly reduced to the
.state of impalpable powder. The fine dust produced in this
way is constantly being sucked off by a f(ui, and allowed
to settle in chambers whence it is conveyed mechanically
into koppers. It can then be drawn off into sacks as required.
As the aspirating force of the fans can be regulated at
pleasure, the mineral can be brought to any desired degree
of fineness without any screening. Before treatment in this
machine, the material must be crushed small enough to be set in
motion by the hurricane-like blast of the beaters; in the case
-of a mineral like quartz the fragments must not be larger than
walnuts.
k. Hifloellaneoafl Fulvsrisers.— These are so numerous
that it is out of the question even to think of giving their names.
The Stuitevant mill bears some resemblance in its mode of
jiction te the Cyclone pulverisers, inasmuch as the particles are
flung against each other with great force and bre^ up in
mid-air, so to say. The stones are prmected, however, by centri*
fugal force and not by air-currents. The Stiu^vant mill is made
of two horisontal hollow cups which revolve at great speed in
• Ittdtutriai Stvieie, vol. i., 1S86, p. 56,
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564 ORE AKD STONE-HINING.
opposite directions. The mineral is fed into the interval betweeo
the two cupK, and as fast as it makes its w&y into one of them,
it is hurled out again by centrifugal force and strikes other
fragments which are thrown across by the opposite cup. IW
?)wdered mineral is drawn off through a screen hy a fan.
hough the hurling cups are cylindrical, the crushed rock pttcks
itseU into the ends and forms a conical stone lining which
prevents wear upon the iron suriacee. The Sturtevant mill u
said to be largely used in the United States for grinding
phosphate of lime.
The crushing machines in these descriptions have been
arranged according to their modes of construction ; it will be well
to point out in conclusion the uses to which they are applied, viz.:
t. Preliminary brsaklng : jaw-breakets, and Gates rook breaker.
a. Coaree cnishinit ; roUa.
3. floe orusbiuK ; itampa, rolls, mills of ranons desctiptions,
and diiint^rators.
I. Sawing Kaohlnea. — These are necessary in the case of
stone and slate. The simplest machine is merely a plain blad^
held in a frame, moved backwards and forwards by a crank or
excentric, whilst sand or chilled cast-iron shot and water are sup-
plied to aid the saw in its cutting work. The wire saw, already
described in a previous chapter, is employed for the same purpose.
Fio. 63S.
Id the case of slate, the work is usually done with circular saws.
The blocks, which have been spUt into slabs about 4 inches thick,
are fastened by wedges upon a sawing table, such as is represented
in Fig. 638. It is a cast-iron bed, A B, moving upon rollers, with
holes into which wedges can be placed for fixing the slabs of alate.
The pulley C drives the circular saw D, and at the same time
gives motion to a chain which draws the table along from one
end of its frame to the other. When the table has gone as &r as
possible, the workman turns a hand-wheel which reverses the
motion, it is drawn back, and another set of slabs are arranged
BO that they may be cut when it again moves forward. The
saw sometimes lies in a semicircular trough full of water, which
serves to keep it cool.
m. Planing JIaohines. — Planing machines, somewhat siniilar
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DRESSING. 565
to those used in engineering shops, are employed for making the
smooth slate-slabs required for cistems or billiard-tableB. The
tool is held in one direction only and is not reveraed after each
stroke.
n. Slate-making UaoMnes. — ^Greavee' circular elate-dreesing
mHchine (Fig. 639) does precisely the same vork as the quarry-
man's knife. It is a frame carrying two knives, C, which are
made to revolve by the pulley A upon the same shaft as the little
flywheel B. D is a fixed knife and E a cast-iron arm with a
number of notches on the inside, which are gauges for enabling the
quarryman to cut the slates to exact sixes. The belt pulley A is
thrown in and out of gear by a clutch.
Another machine for doing the same kind of work acts like a
Fio. £39.
guillotine, and has a knife which slides up and down vertically
betweea guides. In both machines the action of the hand-knife
is imitated — that is to say, the cut ia made gradually along the
desired line.
. (4) AQOLOHEBATION OB COITSOLIDATION.— Pro-
cesseH of this kind are more particularly used in the case of coal
«r brown coal, small particles of which can be pressed, either
with or without the addition of some cementing material, into
blocks of fuel of convenient shapes and sizes. At the same time
agglomeration is not confined to coal : some of the poor clayey
phosphate of lime of the department of the Somme is made into
bricks, so that it may be readily burnt in kilns and deprived of
its moisture before being ground or sent away; the so-called
" purple ore," the residue after the treatment of cupreous iron
pyrites by the wet process, and other kinds of fine iron ore, are
also sometimes made into bricks for the purpose of obtaining a
.product suitable for smelting in the blast-furnace.
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566 ORE AND STONE-MININQ.
In order to get rid of water, washed graphite is preesed into
cakes, which are then ready for the diying stove.
(5) BCBXEJSIsa OB BIFTnra.— This is an importuK
branch of drassing. Sometimes it is a preliminaty prooeas which
is neceasary or advisable previous to cx)Dcentrati<M) bj epeaSe
gravity, or to picking by hand. Sometimes it is a final jnocet^
previous to sale, and for several reasons : the purchaser nsaallT
requires cements, pigments, and fertilisers in a state oi fine sub-
division and free from any coarse particles, or, contrariwise, he may
object to ores in the form of " smalls " or dust, which wonid cho^
his smelting furnaces. Lastly, in a case of coal, which is bqrwd
the province of this treatise, the consumer prefera lumps, because
they bum more readily than dust and afford a rough guarantee
of purity ; whilst with anthracite the sifting process is carried oat
on a very elaborate scale, in order to obtain suitable kinds of fneL
MineraJs are classified according tii size by means of saeves
worked by hand or by machinery,
Hond-Bieves are often employed underground for t^'^Ving oat
"smalls" which are not acceptable to the purchaser. Tbus at
the Merionethshire manganese mines, the workmen shovel the
fine stuff on to circular hand-sieves with holes j inch square, and
use all that goes through as material for filling up. In speaking
of the iron ore worked opencast in Northamptonshire a similsr
separation of the fine was mentioned (Chap. YI., p. 288).
Sifting by hand is shown in Fig. 613 following bucking, so as
to ensure a proper degree of hand -crushing. It is more econo-
mical to employ a rectangular sieve fixed in a steeply sloping
position, and throw the mineral against it with the shovel. Ii»>
clined gratings {grizzliM, tJ.S.) formed of bars of flat iron or steel,
on to which the waggons of mineral are tipped as they come from
the mine, are another form of sifting apparatus.
Uaohine-sieTeB. — Most of the sizing at mines is performed by
ueves set in motion by machinery ; there are two principal kin<b
of machine-sieTea : flat oscillating sieves and revolving cylindrical,
conical, pyramidal, or spiral sieves.
The most common in ore mines arc revolving sieves, either cylin-
drical or in the form of truncated cones. A sieve of this kind is often
known ss a " trommel." The word is expressive enough to the
German ; but it fails to tell the Englishman that the machine is
drum-shaped, and it can be tolerated in our language simply on
the score that it has so long been in use that it is prw^cally
naturalised.
The sifting is done by wire ireb or by perforated sheets of metal,
either iron, steel, copper, brass, or bronze. Figs. 640,641 and 641
represent sieves with round holes i, 3, and 5 millimetres respec-
tively. The holes are sometimes square, or oblong.
The trommel consists of the perforated plate or the wire cloth
bent into the required conical or cylindrical form, and suppc»ted by
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DEESSnfG.
S«7
rings attached by armB to a central axis. The conical trommel has
the advantage that its axle can be placed horizontal, for the slight
inclination of the sieve causes the mineral to make its way from
the feed or smallpr end to the discharge or larger end, provided
of course that the machine is in motion. If the trommel is
cylindrical, its axis must be inclined in order to secure the same
result,
Fio. 640.
Fid, 641.
Jig. 643.
When it is necessary to separate a crushed mineral into a
number of different sizes, the trommels are commonly arranged
BO as to discharge one into the other. This plan has the dis-
advantage of requiring much gearing or many belts, for the
devee have to be arranged step-fashion, each one a little below
its predecessor. If, on the other hand, only one long trommel
is used, with the holes increasing in size from the feed to the
discharge end, there is the evil of letting the very coarse stuff
Via. 6430,
wear away the fine sieve, and cause more frequent repairs.
A good form, made by jacom^ty and Lenicque of Paris, is
that shown in Fig. 642a. The feed-end A is free from cross-arms,
having a large cast-iron ring B as support, and there are in all
three sieves C, E and F. Suppose, for instance, that the trommel
is supplied with stuff which has left a crusher eieve with no particles
bigger than 8 nullimetres (^ inch) across ; this passes on to tlie inner
sieve 0 with holes of 6 mm. (^ inch). The next ring, D, is of sheet
iron. In this way the coarsest stuff never touchra the fine sieve.
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568
ORE AliTD 8T0NE.UINING.
The two nerea, E and F, on the ontside have holes c£ 2 mm. and
4 mm. Oomequentlf this trommel nutkefi four claasee: smaller than
3 min.,t^., tMtwbiobdr^ through the fineetaieve, E; sixes 104
mm., dropfnng thnmgh nere F ; sue 4 to 6 mm., discharged at G ;
and, lastly, aiie 6 to 8 mm., which panee out at H. An objection
to troounds with oonoentric sievea is the difficulty of effecting
repairs inside, if the plates become worn. This defect is
remedied in the trommel figured by fixing on the perforated
plates with screw bolts; they can then be taken ^ qui<^y
and easily.
II. PBO0S88ES DSPENSIira VrOV FHTSICAI.
FBOFSBTIBS.
(1) XOTIOir Iir WATER. — Many of the more important
dressing proceeeea depend upon the rute at which particles of mine-
rals fall in water. The Telocity of fall depends upon the qtecifio gra-
vity and the volume. A piece of salena with a specific gravity of 7*5
sinks to the bottom more quicUy than a piece of qoartE of equal
bulk, which has a specific; gravity of only 26. Nevertheleas,
if the pieoe of quartz is large enoagh, it wiU fall to the bottom as
fast as the emsller piece of galena Articles which have equal
velodties of fall, though differing in siia and specific gravity, are
said to be likt-failing or equivalent.
F. von Rittinger * gives the following table to show the rates
of fall fA spheres of three, minerals differing considerably in
specific gravity :
Galatia .
I Iron pTiites
QdstU .
1!
1
-
iriir
lb
3-6
16
4
IW
4
7-^
1
'
This table shows that the particles at the very outset have an
accelerated velocity, and that the velocity speedily becomes
uniform. It also shows that a small sphere of quarti 4
* L«Arbii«& dir .^H/WtfitKH^-titKle, Berltn, 1867, p. 17S.
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DRESSING. 569
millimetres in diameter aiaks down at almost precisely the same
rate as a sphere of galena only i millimetre in diameter. Thetw
two particles are therefore like-falling or equivalent. It ie
evident that if the sphere of galena has a greater diameter than i
millimetre it will fall faster than the grain of quartz which is 4
millimetres across. Ckinsequently, if a mixture of minerals
differing decidedly in density is separated by sifting into lots
consisting of particles nearly alike in bIm, there
is no difliculty in effecting a separation by their "' ^^'
mere descent through still water.
This fact may be rendered very plain by a
simple experiment. Prepare a mixture of like-
sised grains of coal, calc-spar, and galena by
sifting the pounded minerals and retaining, for
instance, the portion which has no particles
more than | inch in diameter or less than y\f.
Put the mixture into a glass tube 4 or 5 feet
long and j inch or i inch in diameter, corked
at one end (Fig. 643), Fill completely with
wiiter and cork the other end ; reverse the tube
briskly and hold it upright. The galena wilt
fall to the bottom first, then the calc-spar, and
lastly the coal, and the three minerals will f<»-m
separate layen distinctly marked by their
differences of colour. A shorter aod narrower V^
tube may be used, but the greater the depth of !~
the water the more accurately can the descent
of the particles be watched.
The experiment may be repeated by reversing
the tube, for the galena will soon make up by
its high specific gravity for the slightly longer
pnth which it has to travel.
Though the final velocity attained by a par-
ticle of a mineral falling through water depends
both upon its volume and its specific gravity,
it in nevertheless true that in the early part of
the fall the influence of the specific gravity preponderates, and
the denser particles take the lead. This appears from the table.
Take, for instance, a particle of quartz 16 millimetres in diameter
and one of galena of 4 miUimetres, which are practically like-
falling after the lapse of a second ; at the end of | second, on the
other hand, the galena is falling with a velocity 2 5 per cent, greater
than that of the quarts. This fact is utilised in practice, for
instead of simply letting the mixture of minerals fall through
a certain depth of still water, it is made to undergo a rapid
succession of very small falls. In this manner, particlea vary-
ing in specific gravity can be separated into distinct layers,
although they have not been so closely sized as would bare
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570 OEE AUD STONE-MINING.
baen requisite if the aepftrfttion hftd depended upon eqaivHlance
klone.
In a few ezoeption&l caeea the Taluable mineral rises, as it is
lighter than water; when » mixture of oiokerite and clay is
thrown into water, the waste falls to the bottom whilst the
useful Bubst&nce floats and may be skimmed off at the top.
Bitumen, too, oomes to the surfaoe when latuminous sandstone is
thrown into boiling water and stirred.
Groll's process for extracting sulphur from rock containing the
element in the native state, now abandoned on account ci
practical difficulties, is another instance of a separation by buoy-
ancy. A Bolntion of chloride of calcium was prepared strrag
enough to have a specific gravity decidedly above 2 ; when the
rock was plunged into a hot solution of this kind, the sulphur
gradually liquefied, oozed out and rose to the top, leaving the
heavier matrix at the bottom.
A second method of utilising the fall in water consists in
•ubjecting the particles to a current flowing upwards ; by suitably
regulating its force, light particles can be carried away and only
the heavier allowed to sink.
lastly, a third kind of motion is that of small particles cat^
ried down inclined planes by a thin sheet of water.
We have now to consider the various machines by which the
fall in water is made to efiect a separation on a commercial scaler
1. Simple FbII In WMer.
Keere or Dollj-tub.— This appliance is merely a vat or tub
in which the finely divided ore is stirred and then allowed to
settle ; it is specially used for the final treatment of line lead ore
and tin ore. The stirring may be done with a shovel whilst
the ore is thrown into the water, but more commonly blades,
attached to a vertical axle driven by gearing (Figures 644 and
645),* are made to keep the mixture of ore and water in a
thorough state of agitation. When enough ore has been added,
the stirring process {tossing) is stopped and the agitator
removed ; the contente of the vat are allowed to settle, while
the water is kept in a state of vibration by taps upon the outside
from the iron hammer b, lifted by the cams e, upon the driving
shaft. This proceeaof settling is locally called pacKn^/ as soon as
it is complete, the water is baled out or drawn off by removing
plugs in the side, and the deposit is scraped off layer after layer,
increasing in richness as the bottom is approached.
Jigger or Jig. — The principal maidiine for concentrating
particles varying in size from i inch to -^j^ inch is the jigger.
The hand-jigger is merely a round sieve which is charged with
the crushed ore and then moved up and down in a tub full of
" league, "On DreuiDg Tin Ore," i¥of. Min. latt. On-HtoaU, voL t
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water, Each time that the sieve is lowered sharply into the
water, the particles are free to drop a short distance, and they
gradually arrange themselves in layers, the heaviest at the bottom.
and the lightest at the top. On lifting out the mere the light
waste can be skimmed off with a scraper, leaving a well-defined
layer of the heavy rich mineral at the bottom, which is ramoved
separately.
This process of separation can be watched by the aid of a very
simple piece of apparatus which the stu-
dent can construct for himself (Fig. 646). Fio, 646.
A model jigging-deve can be made with
a cylindrical lamp-glass by filing on a
piece of wire gauze by means of sealing-
wax, or by tying on a piece of any net-li£e
fabric. A mixture of crushed coal, calc-
spar, and galena, prepared as in the pre-
vious case, is placed upon the sieve, and
the glass cylinder is now moved down
and up in a laree tumbler partly filled
with water. A distinot separation is soon
Instead of moving the sieve in still
water, it is more common nowadays to
make the sieve stationary and to force
water up through it with a pulsating action. The particles are thus
subjected to a series of repeated lifts and falls, and after the lapse
of a little time the charge of crushed ore placed upon the sieve
becomes separated into a layer of rich mineral at the bottom, and
a layer of light waste at the top ; in the middle there may be a
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37a ORE AND STONE-MINING.
lajer consuting of rich puticlee with more or leaa wute material
AtUcbcd to them.
An illnatntive model is again easily constructed (Fig. 647) by
fixing a pieoe of wire gauze in a lamp-glass, between two rings
cut from india-nibber hoee of suitable diameter, whilst a flexiUe
ball Bjringe eupplies the means of pumping water up and down.
However, this is not the form in which the jigiger
¥10. 647. is made in actual practice. It usually consists of a
box (Avieh) divided by a partial partition into two
compartments ; in one is fixed a flat sieve » (Figs. 64.S
and 649), which carries the ore, and in the other a
piston, p, is made to work up and down by an ex-
oentric. The mode in which the separatioD is effected
can be watched in a model made out of a U-tnbe,
with s round stick or a test-tube as the piston
(Kg. 650).
The great advantage of t hese jiggers is that tbey
readily allow a continuous feed of the ore and dis-
charge of the products without any stoppages. The
ore is fed on by a hopper placed at one end of the
machine, or is delivered already mixed with water.
Several methods of dischai^ can be adopted 1 viz.,
(a) at the end ; (6) in the centre ; and (c) through
the meshes of the sieve.
(a) With the first kind of discharge, the enriched
product lying on the sieve passee out through open-
ings at the end of the jigger, and the amount escaping
is regulated by an adjustable shutter which enables
the size of the outlete to be increased or diminished at
pleasure ; the middle product can be drawn off by open-
ings placed at a slightly higher level, whilst the waste
is washed over a sill at the end of the sieve at each pulsation.
Very often a first sieve simply separates a concentrated product
and dischargee a poorer product on to a second sieve where a
similar separation is effected.
{b) With the central discharge method, a pipe is brought up
through the middle of the sieve, and the size of the opening for
the escape of the concentrated ore is governed by a cylindrical
cap, which can be raised or lowered by a screw.
(c) The discharge through the sieve is specially adapted for the
finer products from the crusher, though it is also used for grains
up to and even above ^ in. in diameter. The mesh of the sieve is
chosen so that the particles under treatment will just pass
through, but above the sieve is a layer {bed) of clean ore, or of
«ome substance of about the same density, in fragmente too large
to drop through. The pulsations of the water cause the usual
separation into layers, and the heavy rich particles find their way
down through the bed of mineral of like specific gravity and
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drop iDto the hntch, whence they can be drawn off through a
hole OS reqnired. The poorer p^ posses ovw a rail at the end
of the sieve, as a wortliless product, or on to a second deve, so
that more valuable mineral may be taken out of it. Three or
four Bievee are often arrangeil in a row in one
maehine, and, by proper arrangement in ' ^
dreesiuff mizeid lead and zinc ores, the first
compaixment may be made to yield clean
galena, the second a mixture of galena and
blende, the third clean blende, the fourth
inixed blende and rock, whilst the greaterpart '
of the waste material passes over the sill at the
end. These jiggers, with the discharge through
the sieve, are commonly known as Hartz jigs.
The number of strokes per minute, the
length of stroke and the thickness of bed
depend upon the fineness of the particles
under treatment ; the former gradually in-
creases, while the two latter decrease as the
particles diminish in size.
The piston of the jigger need not neces-
sarily be horizontal. Messrs. Kitto and Paul
place it vertically in the jiggers employed at
Frongoch mine, Cardiganshire, for treating blende and galena.
A and B (Fig. 651) are the two hutches, and C Is a partition
in the middle. D is the piston working between two plates of
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574
ORB AND STONE-liTNINO.
iron V T. The piston oocopiea the whale length of the jig,
shown 1^ T {Fig. 653) ; it is worked by the rod E, guided
at F, and pusing through a stuffing-box, Q. The recipKNaLting
motion is given by a ctai^ M through the oonnecting-rod L and
Fia. 6jt.
S ■ 8 [
lever H, wbioh traversee the head oF the piston-rod I. The crank
has a long loop, which enables the stroke to be varied. The same
end can be attained by an ezcentric with & slot, which allows the
excentridty to be altered at pleasore. X ^ows where the ore is
fed on, and 0 is the place of discharge of the waste or impoverished
^
I
ore. S is the sieve, and P F are holes with plugs manipulated by
handles not shown in the figures, by which the concentrates
which pass through the sieve are drawn off. K is the pipe bring-
ing in clean watw.
a. Upmrd-ourrant Separatora,
We must now pass on to the second method of utilising the
motion of minerals in water, viz., by subjecting them to an
upward current ; and here it may be remarked that the ctm-
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DRESSING.
57S
tJDUous jig to a certaiu extent produces an action of this
kind, for the light waste, brought to the top by the pulsating
movement, is finally carried away by the outflow of the fresh
water.
Upward-current separators are usually inverted pyramidal or
conical boxes with water under pressure brought in near the
bottom. A stream of ore and water is fed in at the top,
some of the heavier particles sink and make their escape with a
portion of the water, at or near the bottom, whilst the lighter
grains are carried over the edge of the box. A s^)arator of this
kind simply extracts a number of like-falling particles, and
the product may require further treatment before a sufficient
degree of concentration is obtained.
Jaoorndt? and Iionioqae'a BeporstoTB. — Fignres 653 and
654 represent Jacom^ty and Lenicque's pyramidal separator with
six compartments, A, B, C, D, E, E, which make seven cate-
gories from pulp with all its particles under i mm. in diameter.
£!acb compartment is merely a box in the form of an inverted
pjTamid, and for convenience of transport, the machine is made
in three separato castings, which can be easily bolted together,
as shown at R and S. Pipes bring down water from the main
G H, and the amount supplied to each division can be regulated
by a cock ; the water stnkes a little plate attached to tii» end
of the pipe and rises up.
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576
ORE AND STONE-MINING.
The pulp is fed on ftt J and escapee at K. Farticlee which cu
overoome the upward current are discharged contdDuously through
a nozzle at the apex of each i^namid. These nossles are ahoini
at L, M, N, 0, P, Q ; they are easily detachable, and can be taken
Fid. 655.
a
Though separators of this kind are usually employed for the
treatment of fine sand and slime, they are occasionally applied to
oomparatiyely coarse stuff. The separator shown in Vigmr^a 655
and 656 is used at Frongoch mine, Cardiganshire, for treating
an ore consisting of blende and galena, mixed with alate, just as tt
leaves the rolls, after having been crushed fine enough to p«ss
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DRESSING. 577
through a eieve with 1 2 holes per square inch {3 holee by 4 holes).
The coarse goes to the jigs, the fiue to the buddies. It is an
inverted wooden cone A, which can be more or less com-
pletely closed at the bottom by a plug B, controlled by a handle
C. The cone stands upon a wooden box D, which receives
^vater under pressure from a pipe E, and is provided with
a discharge valve F, a mere flat plate of iron, working on a
pin, which can be pushed sideways so aa to close the orifice
partially or entirely. Inside the wooden cone there is a sheet-
iron funnel G, which receives the stream of ore and water
from a launder H, and causes it to descend to the level I.
There it meets with the upward current of clean water, and a,
separation is effected. The coarse and heavy particles which can
overcome the stream pass into the box below, and flow out con-
tinuously at F, while the fine and light particles are mastered by
the current and carried over the top edge of the wooden cone,
which is surrounded by a circular launder. By regulating the
upward current of clean water and the size 1^ the discharge
oriflce, the separator can be adjusted to the requirements of any
particular case.
Ixtokhort's AutomaUo Qem Separator. — In this machine
the particles of minerals fall into a current of water asoenddng in
nn annular space, purposely made narrow in order to prevent
eddies, which would interfere with the desired results. The
velocity of the current can be regulated by stop-cocks, and
arranged so that only the denser of any like«ized particles shall
be able to overcome it and sink. Its primary object is to treat
clean-washed concentrates from gem-bearing gravel after a careful
preliminary sizing by screens.
Siphon Separator.' — A most successful application of an
upward current of water is in the machine known as the «ph(iQ
separator, though its action is not based upon the prin<ap1e of the
appliance from which it takes its name.
It consists of a rectangular box (Figs. 657, 658, and 6^^),'
made of sheet iron or wood with a partition, clividing it into two
chambers B and E. The front one S resembles a pyramidal
separator, receiving an upward current of fresh water from the
adjacent compartment £ and an orey stream from the launder
G, the continuation of which carries away the light waste. The
compartment E has a partition e, dividing it into two parts : A,
which receives a supply of fresh water by means of the pipe a,
and 0, which has the regulating float a. To prevent shoc^ and
eddies, the water does not fall directly into E, but first passes
through holes in the partition u. The precise position of the
float « can be altered at pleasure by the rod /, which connects it
to the lever h, movable about the fulcrum i attached to the
* HeberwischedeaUechemioher BergwaikB-Actien-Verein^ £. tcA,^.,
1886, p. 476.
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578 ORE AND STOXE-MINING.
upright bar t. The travel of the lever is controlled by means of
the rod g. A light rod e carrying the outlet valve is attacbed
to the lever at d; this valve is set in the middle of a pyramiiM
sieve bottom b, and governs the discharge into the pipe q, whicii
Fio. 657 Fig, 658.
leads to the outlet orifice r. The object of these arr&ngements is '
to obtain a self-regulating discharge, the action of ivhich i-
very simple. As the ore-bearing stream passes alone over the 1
box £, the heaviest particles overcome the upward prce^in
of the ascending current and drop ; if the valve is shut, they I
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DRESSING. 579
accumulfite upon the sieve, a.nd prevent the passage of some of
the water through it. The obBtruction causes the water in the
chamber C to rise, the float ascends at the same time, and in so
doing lifts up the valve and allows the discharge of the grains
of ore into the pipe q. The float then ednks, the valve goes down,
another little deposit of ore causes an obstruction and the process
is repeated.
These separators are some of the principal machinee employed at
Mechemichfor the treatment of the friable lead-bearing sandstone ;
in fact, there are no less than 124 of them in use. They are
remarkable for their simplicity and for the large amount of stuff
that they will treat. The quantity of broken sandstone which
can be successfully passed through one machine per hour is from
270 to 300 cubic feet (8 to 9 cubic metres). Sometimes two or
three of these machines are placed one after the other, the second
receiving the overflow of the first, and the third the overflow of
the second.
The quantity of water required is somewhat large — ^viz,, 9900
gallons (43 cubic metres) per hour ; but at Mechernich it is used
over and over again, after the flne matter in suspension has been
allowed to settle.
3. Separation bj Water flowing down Planes.
We lastly have to deal with the third manner of utilising the
motion of mineral particles in water, that is to say, allowing
them to be carried down inclined surfaces by a stream of water.
Two classes of appliances are used : those in which the deposit
is cleaned off as soon as a thin layer has settled down, and those
in which the deposit is allowed to go on forming until it has
attained a thickness of at least several inches or a foot.
(i) The first class includes various kinds of plane and conical
tables, certain percussion tables, and the travelling belts.
Plane Tables. — Plane tables, often called "frames," and
sometimes, but incorrectly, called " buddies," are slightly inclined
rectangular surfaces of wood down which the pulp flows in a
regular stream. An even flow over the whole width of the table
is secured by first passing the stream over a head-board, which
divides it into a numbw of little rills. The strength of the
current depends upon the quantity of water, and upon the
inchnation given to the table. These are arranged so that some
of the mineral under treatment will settle down and resist the
action of the water, which is always tending to carry it on
further. After a deposit of this kind is formed, clean water is
often aUowed to run down over the table to carry off any light
particles intermixed with the heavy ore, and its action is aided
by bruahing hghtly with a broom. The deposit is then washed,
off and collected in a tank for further treatment.
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S8o OHE AND STONE-MINING.
Where the mineral to be treated is poor, the tables hare to t«
worked with as small an expenditure of labour as possible; toi
the device adopted in Cornwall is explained by Figs. 6 60 to 6t>^ '
A is a launder bringing the pulp, which flows down orer the he&>i-
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DRESSING. 581
board B on to the inclined enrface of the table, leaving upon
it, in virtue of their high specific gravity, some of the heavy
particleB of tin ore, and carrying the lighter refuse into . the
launder C. While this action is proceeding, the clean water
launder E is filling the two V-Hke troughs D and D'. When
these are full, they tilt over (Fig. 662) and diacharge their contents
suddenly on to the table, washing off the deposit. The troughs
D and D', on turning over, carry the bar H H forwards, and
thus lift the flaps at F and F", so that the upper and richer
part of the deposit is washed into the launder F, the lower and
poorer part into F'. As soon as the troughs hare discharged
their water, they are brought back into their original position by
the simple cataract Q, and the process is repeated.
Round tables are bluntly conical, convex or concave surfaces ;
with the former the pulp is fed on at the centre and runs down to
the circumference ; with the latter, the direction of flow is reversed.
The tables are made of wood, planed cast-iron, or cement ; the
wooden tables may be plain or covered with india-rubber. They
are stationary or revolving.
An excellent stationary table ia that of Linkenbach • (Figs. 663
and 664). The table itself, a, is made of masonry with a smooth
surface of cement ; 6 is an upright shaft, which carries the pulp-dis-
tributor and the pipes supplying wat«r for cleaning and for wash-
ing off the deposit ; it is set in motion by the worm d and wheel
c. Two of eight radial arms, borne by a centre-pioce, are indicated
by e «; they carry the apron g, the dean water pipes, h, h, h, the
position of which can be regulated at pleasure, and the wafihing-
off pipe ». The clean water is brought in by the circular box k,
rotating with the anus e, and supplied from the pipe I ; the pulp
is delivered through the pipe m, which passes along the conduit ii
under the table into the inner ring o' of the adjustable dis-
tributor o. The distributor is constructed so as to deliver pulp at
0" and clean water at o" ; p p ore pipes bringing down clean
water from the rotating launder k, and g', q", q'" aro three
concentric gutters, by which the various products are led away.
The innermost gutter takes the waste "ttulings," the middle one
the mixed product, and the outer gutter the clean concentrate.
The two latter products are conducted each into its proper channel
by the apron g, which is made of sheet zinc.
The mode of action of this table is easily understood. The
distributor is constantly feeding on slime by the part of its circum-
ference rot (Fig, 664); a deposit forms on the table, whilst the
lighter tailings run off into the gutter 9', which is freely open to
them in the absence of the apron. As soon as the feeding part of the
distributor has passed, clean water begins to flow down over the de-
posit from the trough o"', carrying ofl'tbe middlings into the gutter
* LinkeDbaoh, Die Av/lerriltmg ier Erxe, B«rliD, 1887, p. loi, and plate
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ORE AND STONE-MINING.
Fio. 664.
^**^v!
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DRESSING. 583
q", and having its action aided by the washing-off jets h. There now
remains on the table nothing but a clean concentrate, and this is
wasbdd off into the gutter q'" by the jets t ; r* is a launder carry-
ing away the waste; r" ronducta the middlings to a settling pit
A, and the concentrate escapes by a similar launder r'" into B ;
e is a wire rope for driving a second table.
An easy way of realising the mode of action of this table is to
divide it mentally into three portions — viz., the sector from tiov,
which is receiving the slime ; the sector from t to w, from which
the middlings are being washed off; and lastly, the sector from v
to w with the clean concentrate, wlkich yields to the jets issuing
from i, and passes over the apron into the outer gutter q'".
Where the amount of space is limited, Linkenbach places three
tables on the same central shaft ; but the economy of space and of
original first cost Is accompanied by less easy supervision.
The mode of action of roimd tables is very often just the
reverse of what has been described ; that is to say, the table
revolves and the distributor is stationary. Linkenbach points
out that a revolving table is necessarily subject to vibrations,
which must interfere with the evenness of the fiow down tho
inclined surface, whilst the fixed table with a travelling distributor
is free from inflaences of this kind and is likely to work more
regularly.
Nevertheless, in spite of this objection, revolving round tables
may be seen doing good work. The table represented in Pigs, 665
and 666 is one designed by MM. Jacom^ty and Lenicque. A is
the head-board or distributor which feeds the table B with a
stream of the fine slime ; the table is made of arms of T-iron,
radiating out from a cast-iron centre-piece C, which support a
light coveringof planks. Over this is stretched sheet india-rubber,
which forms a smooth surface, free from any liability to warp
and get out of shape. The table is set in motion by the vertical
shaft D, driven by the wheel G- and worm H. L L are various
pipes bringing clean water, supported by rods N N, and capable
of being placed in any suitable position. M M are pipes which
wash off the deposit from the table ; they are held op by
standards N' N', which can be shifted about at pleasure. K is n
circular launder round the table, with discharge holes t I, and
movable wooden partitions «, »', s", a", »"" ; lastly, the pipe 0 sends
out jets of water which c]e«n off everything remaining upon the
table. If the table is supposed to be moving in the direction of the
arrow, it is evident that products of different kinds will be washed
off at different periods of the revolution, and that towards Uie
end nothing will remain on the table but the heaviest particles.
By suitably arranging the amount of feed and the position of the
different wasbing-pipes, the table can be made to give clean ore,
waste, and intermediate products ; the latter are passed over the
same or a similar machine once more.
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584
ORE AND STONE-MIXING.
The table is 16 f«et 5 inches (5 m.) in diameter, with a isefal
working surface 4 feet 11 inches (1*50 m.) long; it makes ok
revolution in 3i minutes, requiring lese than ^ h.-p. to work it.
The quantity of water used is about 26 gallons (tzo litres) pa
minute, and the table will treat from 5 to 8 tons of sUme in tMt
hours. As it is made of eight segments bolted together, it ii
easily transported and erected.
IS?
PerousBion Tables. — Rittinger's side-blow percusmon Ub(«
(Fig, 667) is an inclined rectangular platform suspended by th^
four Cornell ABC D, receiving blows and bumps on the side- i-
stream of orey water Sis fed on to the comer A, and clean waterff
runs down from other head-boards HHH. Bymeansof cams upon
a revolving shaft, the table is pushed out in the direction of the
arrow, uia it is then driven back by a spring, so that the cross-pieN
£ strikes against the bumping-block L. The light particlee trare)
down the table much faster than the heavy ones, and taking *
comparatively straight course, leave the table at E ; whov^s
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DRESSING.
S8S
the heavy and richer particlee remam oa th« table, subject to the
iDflueuce of the eide-blowe, for a much looger time, and travellinj;
along a ciirved path reach the bottom at F. An intermediate
product is discharged at G. The exact degree of richness or
poorness can be regulated by pointers, strips of wood which can
bo turned so as to divide the stream of ore and waste where
thought most desirable. The great advantage of this machine
over the old percussion frame is its continuous action.
Travelling Belta. — We now come to the travelling belts, of
which there are many yarietiea. An early form was that of
Brunton,* an endless belt of canvas acting in the same way as
Fig. 667.
Fig. 668.
1^=0^
S^^^^
the now favourite Frue-vanner, save that there was no shake
sideways. In fact, the latter machine is regarded by some as an
improved form of the Brunton cloth.
The Frue-vanner (Fig. 668) is an endless band of india-rubber
cloth, 4 feet wide and 27 feet long, with on upper working surface
of about 1 2 feet in length. The belt is supported by a f mme with
a number of small rollers on which it travels easily, and it is
driveB elowly in the direction of the arrows by the npper
end roller shown in the figure. The small roller by the side
of the large one, which dips into the tank, serves for
tightening up the belt when required. The whole frame
carrying the belt receives a motion sideways from three little
cranks upon a small shaft running parallel to its length. The
pulp is fed on by the head-board A, and clean water by
another B. The natural path of the particles is down the
inclined belt, but those which can resist the action of the
* Bepwitb, "The DreEsingofLeadOrss," iVnc. 7R«f. C f ., vol. zzx., 1870,
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586 ORE AND STONE-MINING.
sta«am of clean water kt B, go over the top end, and an vuke-l
off an the belt passes through the tank. The pow stuff i-
discharged into the vaate launder at the other end. The i»pff
of coDcentratioD can be regulated by the slope and speed li ttr
belt and the Btrength of the streams of ore and water. Tit
Frue-vtuuer has the diaadvantage that it makes only two cluat^
rich and poor, without any intermediate product.
Tbesuccees of the Frufr-vanner has naturally brought a nomW
of somewhat similar contrivancee into the market. The IjiibRj
concentrator may be likened to a Frue-vanner, with a loagitmiiiuJ
instead of a lateral shake.
The Woodbuiy ore concentrator is made up of several tuhw
belts each with its own flanges, instead of there being one tnwi
band. The object of this arrangement is to prevent owftn-
ness of flow, for if strong, irregular currents! are formed in ibf
centre of the belt, they may carry away good ore into the wi*
launder.
Stein's endless belt, which has been improved by Bilhan, la*'
totally different mode of action. It resembles the Biltiiii"
percussion table in its manner of effecting a separaticm, but ^
work is done on a travelling belt instead of an unchaining cor
face. Stein's machine* (Figs. 669, 670, and 671) is a recUngulv
frame a, suspended between two posts p, by rods 1, at the four
comers, so that it can swing in the direction of its long dde. Tb;
inchnation of the frame can be altered at pleasure, by the hudK
attached to the cross-beam /, which works upon the screw «, ^■
the long side always remains horizontal. The frame is drawn slig)i>^
out of position by cams r, acting upon the lever m, and as soon i-
it is released it is pulled back against a bumping-piece t, bv ■
spring n. The frame has two large rollers c e, and three small od^
underneath, which carry an endless belt of india-rubb«-/, thenpt^
part of which is further supported by the flat bed of boant f
The belt slides over this bed, and is prevented from sticking to J'
by a constant flow of water, supplied by the pipe g, along oantK
diagonal grooves. One of the end rollers is made to involve and
carries the belt with it. The pulp is fed on by a head-board i-
and clean water is turned on through holes in l>he pipe o. Th
direction of travel of the belt is indicated by the airow, TIk
concentrating action is like that of a Bittinger table. Tbe
lightest particles run down at once, and leaving the belt *t lb'
right-hand end of the table, fall into the first compartment of tt'
launder q, whilst the heaviest remain on the table much leo^-
and ore finally discharged at the left-hand end. Intermedin'
products run off in the middle.
(2) The second set of appliances includes the huddles 1^
ordinary percussion tables.
* Blomeke, " Ueber den Stein'Kchen PlanneQ-Stossberd," B. n. L ^
1891, p. 69.
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DRESSING. 587
Buddies. — The hand-buddle is a rectangular wooden box with
a slopiog bottom. A stream of pulp ie fed in by a liead'board at
Fiaa. 669 aud 670.
the upper end and gradually forme a deposit on the floor of the
huddle. A hoy with a broom keeps the surface of the sediment
even, so aa_to ensure regularity of action. After a thick deposit
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S88
ORE AND STONE-MINING.
has accumulated, it is dug out in aectiouB, which decrease in ricb-
DBBB from the upper eod {head) to the lower end (tair).
Bound buddies bear the same relation to hand buddies that
round tables do to hand frames.' They may be concave or
convex, but the latter are the more common.
The convex round buddle (Figs. 672 and 673) is a circular pit •
with a truncated cone, or head, of varying size in the centre, and a
bottom sifting towards the circumference. The orey stream, A,
Fio. 672.
falling over this bead runs down gently, depoeiting the heaviest
particles near the top, the lighter ones further down, while tbe
lightest of all flow away at C The surface of the sediment is
kept even by tbe revolving brushes D. This machine may be
compared to a number of hand-buddies arranged radially round
a centre. The deposit which Is formed is dug out in rings of
varying richness.
The concave buddle is a circular pit with tbe bottom sloping
* Hoarr T. Fei^Eon, " On the Ueohanical ApplianceG used for Diesoing
Tin and Copper Ores in Comir-" '■ "- ' ' ^' ' "■' " ' '"
andpt 124.
■. Jntl. jUfch. K«g., 1873, plM« xll..
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DRESSING. 589
towards the centre. The stream of ore is fed all round the cir-
cmaterence, and runs inwards towards the middle, where the
lightest particles escape. The rich head is, of course, near the
circumference.
Ordinary Feronssion Table. — The ordinary percussion table,
though rarely if ever seen in this country, is still employed in
Germany and regarded with favour. Those familiar with the
band-buddle will understand what it is like, if it is described as a
swinging hand-buddle which is continually being bumped at the
upper end. It is a shallow rectangular sloping wooden or iron
tray suspended from the four comers, so that it can move back-
words and forwards in the direction of its length, and as soon as
it has been pushed out of position by a cam, it is at once forced back
by a spring against a fixed wooden bumping-block at the upper
«nd. The pulp is fed on at the upper end by a head-boiuil,
and the lightest particles run o£f at the lower end, which has no
rim, whilst the heavier and richer ones form a gradually thickening
layer upon the bed. When sufficiently thick, the deposit is
shovelled off in sections varying in richness as tb^ do in a
buddle. The bump assistB in making the particles settle, just
as it does in the " keeve," and at the same time, in virtue of the
vi» viva acquired during the backward stroke of the table, grains
of ore are constantly being thrown up a httle, as they are with
the German hand-washing dish.
Machines of this class have two grave defects : careful watching
is necessary, in order to keep the surface of the deposit perfectly
«ven ; otherwise gutters are formeil, down which the water runs
with too great a velocity, carrying away rich ore or depositing it
near the tail end when it ought to have subsided at the head.
Secondly, the deposit has to be shovelled off, and the parts
requiring further treatment have again to be mixed with water
and brought into a proper consistency, before they can flow on
to other machines. In spite of these drawbacks, buddies and
percussion tables are still largely employed.
(3) KOTIOIT IN Allt. — In countries where water is scarce,
or where the valuable mineral is specially liable to be affected
or carried off by water, engineers have long desired to employ
air as the medium in which the concentration should be effected.
Three kinds of machines are used : the pneumatic jig, the fan,
and the centrifugal concentrator.
Fnemnatio Jig. — The pneumatic jig resembles the hydraulic
jig in principle ; that is to say, particles of minerals varying in
specific gravity can be separated if they are lifted and then
allowed to fall again, provided that the sizes of the grains do not
iliffer too widely, and that the specific gravities do not approach
too closely. The principle will be most easily grasped if the
fitudent constructs a very simple model (Fig. 674). A. jnece- of
gloss tube with the upper end covered by net or mnslin is
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590 ORE AND STONE MINING.
inserted into a slightly larger tube. The lower end is thei
connected to ui india-rubber pump, such as is used with sceci
diffusers. Pour ft mixture of IiJce-aued grains of gBjeii& and sand
on to the sieve, and give the pump a succession of gentle squeeze;.
Puffit of air are sent up through the sieve, and the tvo
Fio. 674. minerals arrange themselvee asshowii, the galena belix,
and the sand above.
By using a bed of fine shot, jigging throngh th«
sieve may be carried out, the action resembling that of
the Ilartz sand- jigs.
Krom's* pneumatic jig, which is in actual use for
treating silver ore, is a wooden chest in whidi a flu
vane moving backwards and forwards senda a nombef
of rapid pxSe of air through a bed of fine <ve, reetine
upon a sieve made of short upright tubes of wire dotb.
with small spaces between them. The fine ore is M
in from a hopper on one side of the long narrow sen.
The repeated falls bring about a separation, uid tht
light waste passes over the edge of the sieve opposin
to the feed-hopper, whilst the concentrate sinks dovL
through the inUirspaces between the sieve tubes into
a reservoir, from which it is dtawn off gradually by
a fluted roller. As this reservoir is always k^>t foL
the rate of discharge and degree of concentration oe
be varied by altering the speed of the roller.
L_> Fans. — A fan is used in ctmitet-
^ ^ tion with some grinding machine-
in order to draw off the powd»e>i
mineral, and, in dealing with *
homogeneous substance, the amount
of suction can be regulated eo as not
to draw the mineral out of the
machine until it has been sufficientlj
pulverised. If the duet-laden air is then discharged into a lai^
chamber, the coarsest particles will settle down first, ivhilst the
finest will be wafted to the far end.
As an instance of fan-action, the dressing of pJiosphate of Umt
may be mentioned. Some of the phospt^te of lune which is
ground between millstones in France is not passed through anv
sieve at all ; a fan is adjusted so as to draw it away from die mill
sufficiently fine to be put into sacks at once. Teats are made
from time to time to see that the product is properly ground,
for it is sold with the guarantee that not more than a certain
percentage shall be too coarse to pass through a given «eve.
Another example may be taken from some of the fullers-
earth dressing establisikments. The earth is ground in as
* CaUon, " LeotcreB on Mining," PariBand London, 1886, voL ill., p. 104
and Atlas, plate civ.
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DRESSING. 591
Askham mill and forced by a. fan into a chamber some 50 feet
long by 10 feet wide, where it dtops upon the ground ; the deposit
is shovelled away afterwards in sections, which are finer aad finer
as one goes away from the orifice through which the dust enters.
The requirements of different customers can thus be satisfied.
When a fan is employed for drawing off the fine product from
a mill or crusher, it likewise serves the useful purpose of pre-
venting the atmosphere of the works from being polluted by
noxious dttst.
Gmitrifi^^ Oonoentrotor. — These concentrators are based
upon the fact that when bodies of equal volume are whirled round,
the centrifugal force developed is proportional to their densities.
Therefore, if the like-sized particles are projected by centrifugal
force from a machine, the denser ones, with their larger store of
energy, will be better able to overcome the resistance of the air
than those which are specifically lighter, and will consequently
travel further. The truth of this can be made manifest with a
child's top. Spin the top in a saucer or dish raised a little above
the table, previously covered with a sheet of paper or cardboard,
and feed on to its fiat upper surface a. thin stream of finely
powdered galena and sand, which has passed through a sieve with
100 holes to the hnear inch and refused to pass the 120 mesh.
The particles will be whirled off, light sand will drop close to
the saucer or even into it, whilst the heavy galena picks up a
larger amount of enei^y from the spinniag-top and files further
away before settling. By brushing
up the diist ooooeatrically, the ^'°- ^75-
etiect will be apparent.
The Glerkson-Stanfield concen-
trator (Fig. 675) works precisely in
this way. B is a distributor, which is
made to revolve rapidly by its spindle
0, The hopper A supplies it with
finely powdered and carefully sized
ore, which escapes by a number of radial boles. The dotted lines
show the paths taken by the particles of mineral, which drop into
a series of concentric troughs from which they can be swept by
revolving brushes into discharge-spouts.
In order to work successfully, the ore must be very carefully
separated by screening into particles of approximately the same
volume. The machine is new, and has yet to bear the test of
actual practice on a large scale at mines, but it is worth noting
that a similar appliance is used at mills * for freeing semolina
from bran and dust. The Pape-Henneberg f ore concentrator is
identical in principle with that of Olarkson and Stanfield.
A disadvantage of all pneumatic dressing is that the ore has to
* Spon's Dictionary of Enginuriag, London, 1873, vol. vii., p. ?499.
t E. V. h. Z., 1893, p. 191.
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591 ORE AND STONE-MINING.
bo very thoroughly dried, for otherwise the particlea stick togwbef
fdightlv and counteract the action of the forces whicli should e&it
the desired separation.
(3) J>S8ICCATIOir. — Various reasons call for the drringci
minerals. Sometimes the mineral cannot be ground tmtil ii is
freed frcon moisture ; in other cases drying is advisable in order xo
save the payment of carriage upon a useless ingrodient ; it is lik^
wise necessary before a taineral is roasted in furnaces, or ptama
through wrtain magnetic separatora, and, as has jnA be^i
remarked, it ia indispensable when the subsequent treatmeui l~
effected by a pneumatic process.
Drying may be carried on in one of the following nrays :
a. By exposure to the air. I
b. By open Area.
e. On open floors or pans. I
d. Id enclosed stoves or kilns. I
e, B7 filter presaea.
a. Air Drying.^Simple ezpoeure to the a«ti<Mi of ikf
atmosphere, under a light roof as a protection from occssioLa
showers, is quite sufficient for the purpose of drying mani
minerals, provided that the weather is fine. China clay asii
ochre are sometimes dried in this way. The roughly cubical dod>
are piled up one above the other, allowing free access of air, anJ.
if the weather in favourable, a sufficient amount of mmstxf
evaporates naturally to render the mineral fit for the marki^:
but a wet season sadly interferes with the work, frost will anse
the clods to crumble, and artificial drying often becomes nece^^an
in order to satisfy the demands of customers.
In Chili the crystals of nitrate of soda are soon dried perfectlv
by exposure to the atmosphere.
b. Open - fire Drying. — The phoephate of lime dug cr
dredged in South Carolina is sometimes dried by heaping it upoa
piles of wood which are set alight.
c. Drying on Heated Open Floors. — Heated floors are em-
ployed in drying barytes, fuller's earth, and phosphates previoit
to grinding, other minerals previous to roasting, and cluna clay
previous to sale.
Fig. 676 shows a Cornish " dry" for china day.* Thelettas I ■'
repre^tent the " settling tanks" or stone-lined pits into which the
clay is run, in the form of a tbin mud, after the coarsest particks
of the decomposed granite have been separated. Here it forms
a sediment of the consistency of thick cream, which is trajnmed
to the " dry," after the water has been drawn off. The drviiu:-
house is composed of the dry proper m m, and the storing shed-
or " Unhays," 0 o. The floor of the dry is made of large fire-f-iav
tiles, which cover a number of flues, each about 14 inches wid«.
* Collins, " The Hensbarrow Granite District," Tmro, 1878, p^ 20,
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DRESSING. 593
leading away from the fireplacee, « «. The tiles are 5 or 6 inches
thick over the fires, where the heat is greatest, and the thickness
is reduced to 2| or z inches at the other end of the building. The
clay is trammed in along the road 1 1, and tipped on to the floor or
" pan " m m, nntil it forms a layer 9 inches thick at the fire-end
and 6 inches thick at the stack-end. The clay at thn fii<e«nd
is dried in 24 hours ; it is cleared off and stored in the linhay
0 0, and another charge of wet day trammed in ; the further
the clay is from the fire, the longer it takes to dry, and at the
stack-end, the " pan " can be cleared and re-loaded only twioa
or three times a week. It appears that much more of the
moisture soaks down through the tiles and is carried away as
steam by the fiaee, than evaporates from the surface of the pan,
and for this reason the tiles are made as porous as possible.
The open floors used for drying phosphate of lime in the
North of France previous to grinding have the bed made of
sheets of iron. The plates are about one metre square and
are laid upon a series of parallel fluee formed of little walls one
brick thick. The floors are often about 30 metres long and 4
metres wide. In order to accelerate the process of diying the
sandy phosphate is shovelled over from time to time by men, but
the cost of labour can be reduced l^ using Amett's mechanical
hoe which performs the same office. It is a frame stretch-
ing across the whole width of the floor, carrying a angle
row of broad blades or spades, which can be inclined at any
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594 ORE AND 9T0NB-HINING.
desired angle to ike bed; it is drawn backwards aad is
wards br machinery. The blades pass into the la.yet at fibae^jse
on the floor, heap up the stuflf in front oF them, and caose ti'
particles to monnt np, and then fall over on to Che bed t^
Each time the hoe passes along, the stuff is shifted fwwtnli i
little, so that when the frame arrives at the end of its ctmne.t
puehee off a portion of the charge, which is now dry eaoo^ f^
milling, as it has travelled along the full length of the bed. ii
the inclination of the blades can be altered, the rate at whidi itt
stuff is carried forwards can be regulated so as to prtdoof
shorten the drying procesB, as required. The machins is ibu»
to reverse ita direction of travel automatically, bat it doef »
Btirring on the return stroke.
Thelen's drier is an open semi-cylindrical iron pan heated b; i
fire below, in which the chaige ia stirred by knives moved n^
chanically.
d. Stoves and KIUib. — The number of kinds of endoaed sukt--
and kilns employed for drying minerals is very great ; and it -'
especially in the case of brown coal* that the ingenoity of ist
ventors nas been exercised to devise means of getting lid it
moisture. However, as the subject of brown coal does not bete.
to this work, the special stoves made use of cannot be dealt iHc
at length ; still it is right that they should be mentioned, as aaa
of them could be used for other minerals.
With such a large number of drying stoves, it is abeolntay
necessary that there should be a classification of some kind, fa
otherwise the student runs the risk of being confused.
It is perhaps most convenient to cIosEdfy t^em first of all aoecri-
ing to the motle of heating, and then make a further Babdiristx
aocording as kiln or furnace is stationary or revolving.
Endoted KUtu and Stoves.
HodtoTHntlB^ KindafDrrlagBuiftoa. Nan* or Diyl^ Sbn
IBtatioDuy
Bevolvi&g ... Brnnton'H furnace.
Roelle's stove.
Bowoldt's
fStatlonary ... Steam stove.
"""^ — IRevolving ... Schuli'a stove.
Hot air and itMun ... Statiooaiy ••■ Jaoobrs stove.
Ameriean Photphate KUn.—The kilns employed for dryiL:
pho^hate of lime in South Carolinaf ^ter washing axe wa^
• Tollert, Ber BrautJcoUeribergbau im Oberbtrganti-Bmrt Ht^mi ■
iM (mgrmteoden Staalen, HaUe a. d. S. 1889, p. 249.
t Benediot, "Hining, Washing, and Caloming Soath Carolina Dc:
Pfaocpbate,"l&v ^^n- ^'"^■' ^^^ ^^' '^'> P- 349<
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DRESSING. S9S
rectanguUr chambers, built of brick and roofed with wood. The
wbole of the bottom, is covered with a pile of wood, on to which
the wet phosphate is tipped from barrows. The wood is set alight
and flues sapplj it with air for oombustion. Each kiln holds
from looo to laoo tons of phosphate; the fire burns out in from
two to five days, and the phosphate is then ready for export.
FvUer^ Eitrth KUn.—'Ybxi fnllers' e*rth kiln may be taken
as another example of the first class. It is a brick or stone build-
ing about 36 feet long and 1 5 feet wide, with an arched roof of
briii (Fig. 677) or a sloping roof of slate. About 9 feet above the
bottom is a floor a, made of cast-
iron plates fuU of holes about J *■'"■ ^'?-
inch in diameter, underneath f'''"^•»^■'-
which are two sets of slopiiu; ^ ' i ' > '^-
shelves, made of sheets of iron, b 0,
c c, which can be taken out at
pleasure ; <2 is a deep flue bringing
m air from the outrnde, and having
two openings into the kiln, covered
with fire-bu«, upon each of which
a coke fire, e, is maintained. A
sheet of corrugated iron,/, is huug
up over each fire, in order to pre-
vent the clay immediately above
it from being too strongly heated.
Both the upper and lower floors
of the kiln can be entered by large ^^^^^ ^^ ^^^
doors. The charging is all done » 1 ^ 1 i;
from the floor a ; a few of the waix sr Mmn
platce are taken up on each side, TnT* — I — ! — j — t — '•
the sheets b b removed, and olay
is wheeled in barrows along a and tipped on to «. The plates h
are replaced and similarly covered with a charge of clay, and
finally a receives a layer of damp clay 6 or 8 inches thick. The
doors are shut and the fires lighted ; though the heat is con-
siderable, it is not enough to prevent meugoing in from time to
time to put on more fuel, if required. The moisture-laden air
ascends uul escapes through the roof at e/.
Krom'a Stove.— ^laia'a stove has a series of inclined shelves,
flomething like those of the Hasenclever furnace, down which the
mineral gradoally makes its way under the action of gravity,
while exposed to the direct action of the hot gases coming from
afire.*
Ritbeek'a Stove. — Riebeck's "Tellerofen" consists, as its Ger-
man name denotes, of a number of superposed circular plate-
like shelves ; a central revolving shaft carries arms with
* Sablln, " Hagoetio S«pa»tiwi of Iron Ore," Eng, Mia. Jour., voL Uii.,
»89», p. 638.
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59*
OBE AND STONB-MrNING,
'h
i 1 \
■( ^ ' /.I
~T^
bf^
^^
1
.^■.
-pn
\
/
i
■■•. f
\
t:
}
c
-J
\
a
;:-:;^
— n
^D
-JUi
Iweth or knives whicb altornuti^
caose the mineraJ to ti»vd cQ-
wmrds and mwards. Thv it'i
nunenl fed on to the top $1»-,
for instance, will be made v-
travel oatwanjs to tbe dmunf^-
ence, where it drops tbm^ii
holes on to Bhdf Ko. i ; bei« itt
revolving teeth, arranged in tb*
reverse ^ahion, draw itin^>
ally to the centre, irtiere it fiii
upon shelf No. 3, and it goa en
travelling backwanls and fa-
wards in this faitfaion nntL n
reaches the bottom of the t2L.
Ihiring aU this time it if su:-
jected to the action of tbe bn
gases ooming firom a fire bdov.
Bmnton's caldner (Kg. 692) »^
invented for the pnrpoee of n»?-
• ing ores, driers have been «&
structedni
ithes
epnnnjvi'.
, the stove la a circular revolvia:
horizontal bed, with t««th fis^i
above it which cause the Dunoil
* fed in at the centre, to travei
gradually to the drcumfraeim
. A fireplaoe on one side amds ii*
product* of combustion direct:;
upon the mineral. This stov? >
' used for pho^hate of lime, b^
: sidee being employed in ;x
manufactare of patent fueL
RudUt Sfcrv.—'B.aeae's re-
volving drier (Fig. 678), on lU
other hand, recalls the Hocku
and Ozland calciner. It is mac^
of two long truncated cones c:
boiler-plate, (me inside the other ■
the inner one is deetincd l\i
the drying proper, and the ou:«
one allows the very bot tninon:
to cool down a little before i'
is discharged and sent to t^
ground.
The outer shell rtms upon fri,-
tion rollere, and both it and tb
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DRESSING. 597
inner caee have internal projecting spiral blades, which lift the
mineral a little and cauise it to travel along. At one end there
is u fireplace ; at the other a charging hopper and a duat-chamber.
Ihe mineral fed by the hopper into the inner oone is gradually
brought along by the spiral blades towards the fire-end, whilst it
is being exposed to the hot gases of the fire, as well as to a current
of hot air blown in by a fan, and heated by ite passage through
pipes at the side of the fireplace. On reaching the fire-end of
the inner cone, the mineral foils through one of four holes into
the outer shell, and is now conveyed back by spiral blades to the
«ther end, where it drops into the pit of an elevator, which lifts
it high enough for the hopper of the mills. Any dust carried off
by the draught is deposited in a chamber built for that purpose,
'^ia drier does good work at phosphate mills.
Sowoldt's b'taoe. — This stove, which is specially designed for
brown coal, is made up of a number of email lattice-like shelves
down which the mineral gradually dropE^ while surrounded by
air warmed to 75° C. (ifiy'F.) by its passage through small pipes
heated by steam.
Steam Stove. — The steam stove, also deeigned for brown coal, is
somewhat like the ordinary " Tellerofen." A number of circular
drying plates are superposed one above the other in a cylindrical
casing, and are heated by steam passing under them.
Schuh't Stove. — Schulz's steam stove is a large revolving iron
cylinder like a tubular boiler, 19 feet to 20 feet long, and 7
to 8 feet in diameter, traversed by 180 or 200 small pipes 4 inches
in diameter and a large central one. The cyUnder is inclined to
the horizon at an angle of 5° to 6*. The exhaust steam from an
«ngine is passed into the large central tube and finds its way
thi'ough holes into the space outside it, heating the small tubes
and their contents. The mineral is carefully fed from a hopper
into the small tubes at the upper end, so as to prevent any chokiiig,
for otherwise the free passage of the air would be impeded, and
the drying would be very imperfect.
JacobCa Stove. — In the Jacobi stove the mineral falls down
over a series of pentagonal cast-iron pipes heated by the passage
of steam, instead of taa plain lattice-like shelves of the Bowoldt
apparatus, in addition to being exposed to an atmosphere of hot
air.
Many of the brown-ooal driers are specially designed so that
the products of combustion of the fire do not come into contact
with the mineral, for fear the charge might be ignited accidentally.
This difficulty does not crop up with many of the other minerals
which have to be dried, though it is important with some that
the degree of heat to which they are exposed should not be too
great.
(4) liZQUEFACTIOlf AKD DI8TILI.ATIOK. — The
miner resorts to melting as a purifying or preparatory process in
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598 OBE AKD STON&KTNLNa.
treating amber, ftntimony ore, asphalt, ozokerite, and snlpiix:
aad in tiie very exceptional case of carbonic acid, a gas is ke
preeaed to the liquid state.
Small lumps of am.ber, after having had the dark tmiaToi
dissolved away, are melted together before bein^ aolA to tbf
Tarnish merchanta.*
The liquation of antimony ore is naually regarded as s nwut
lurgical process ; but if a mere melting is carried on at the miu
in order to rid an ore of ear^y matters, there is no oHxe r:i'':i
for refusing this operation a place among " dressing " jsuasRs.
than there would be for exduding the wmiltir pnrificatiati d
asphalt, ozokerite, or sulphur. This is an instance of the difficolir
of defining the boundaries between the prorinoe of the miner tic
that of we smelter. The domain of the former is alnadr >'
large that it does not require to be extended yinnnrrnmrilT, u.:
an the liquation of antimony ore is fully described in muy
metallurgical text-books the process may be dismissed here ic i
very few words. It is based upon the easy fusibility of stiteiv.
The impure ore coming from the mine is subjected to the act: c
of heat in pots or tubes ; the stibnite melts, trickles away in-
the earthy matters with which it is mixed, runs into moulds \d.
is allowed to cool gradually, furnishing the crude antimouv 3
commra-ce.
Trinidad pitch is purified or refined in the island by bebr
melted in iron pans ; much of the intermingled earthy nutiTr
sinks, and the supernatant comparatively pure product is 1^ -•:
out into moulds.
The asphalt rock of Seyssel t is prepared for the maiket h
melting it up with Trinidad pitch, or pitch obtained from btrt
minous sandstone, in the proportion of i of pitch to 14 of :b
finely crushed rock. When the mixture has become pasty, i: a
cast into blocks weighing about ^ cwt. each. These are ir»
ready for sale for making pavements.
The sponge-like masses of gold obtained by the distillati'^
of amalgam are melted in crucibles and cast into ingots i'l^
The comparatively clean pieces of ozokerite, which hare bfa
picked out, below and above ground, and scraped clean, tn
more fully purified by melting; the heavy refuse sinks to th
bottom, whilst the pure wax is decanted off and poured a.:-
cylindrical moulds.
By far the greater portion of the native sulphur of Sidij i
extracted from the limestone, or other rock by which it is accii
paniod, by a simple process of liquation in kilns; the necessan'
heat is produced by the combustion of part of the solpbur u
the rock, it being cheaper in Sicily to do this than to impc'it
* B. u. h. Z., 1887, p. 24.
t MaJo, L'A^lmUe, Fans, 1888, p. 53.
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DKESSDTa.
599
fuel. The " calcarone," * or large kiln (Figs. 679 and 680), ss
digtinguiBhed from the " oalcarella, " or small one, is a circidar
pit fiumnmded by a wall, having a eloping bed leading to a
rectangolar aperture in front. Tba bed is covered with a layer
of bunit refuse (^ineee) from a previous operation, which is
stamped down hiu-d. The charging proper tlien begins, the
large lumps are placed on the bottom, and various small
vertical chimneys are left as passages for the air; when the
" oalcarone " is full ap to the level b e, the mineral is heaped up so
aa to form a oonicsJ pile beds, which is covered over witb a
Fig, 679.
layer of fine " ginese." The thickness of the outer covering of
refuse varies according to the aeason. The total charge of a
large " oalcarone " may be as much as 700 tons. The aperture /
in front is closed with a thin wall, built with plaster of Paris, and
the charge is lit at the little chimneys. The heat produced by
the combustion of part of the sulphur liquefies the remainder,
which gradually runs down the bed to the front wall, and is either
tapped from time to time or is allowed to escape continuously
into moulds. Some of the large " calcaroui " take three months
before they are burnt out completely.
It is reckoned that one-third or even two-fifths of the sulphur
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600 ORE AND STONE-MINING.
in the rock are consumed in liqnefying the part ik; i
obtained. This immenae loss of such a valuaUe maUitt! ':i-
veiy oatntally Ckosed inventors to turn their attentian to dt^-
methods of extraction; but even as late as the ;au li-
nearly eevfln-eigbths of the total quantity of solphnr obUuML
8idly were extracted by the "calcarone"prooeGs. Ahttieni:'
by a Btecun extractor and about lo per cent, of the tcOl ^-
duction by Gill's regenerative furnace ; * the former it u i^'
veseel into which steam is conducted after it has been filkd n.
mineral; the sulphur melts under the action <i heat unlc^-
ont at the bottom.
Rich sulphur rock ia sometimee subjected to distilliliin '
iron retorte in order to extract the valuable element vtb W*
loee than that of the kilns, and the process is also emplontl i:
expelling mercury from amalgam.
In Older to produce a commercial article suitable Cor i<^-
to a distance, the natural carbonic add of Gennany is <»mp^e^«:
into the liquid state. The gas coming frcnu the bore-hole u led t^-
double pamp. The first pump compresses the gas to a an^
extent, and forces it through a worm in a cooling tank ; a settt'-
pump then takes up the process, and compre^ang tbe^-'<-
further sends it through a second cooling worm into ^^.
battles, made of wronght-iron or eteel, in whidi the actou W^
faction takes place at a pressure of 31 atmospheres.
The bottles are of four aiees, for holding 4, 8, 10, or so B*
of liquid acid. An 8-kilo. bottle weighs 37 kilos, when m^
or 45 when full ; the dead weight which has to be transpMl«'
therefore very great.
{5) MAGITBTIC ATTBACTIOK.— Mi^netism b m^
in dreeaing either for treating poor iron ores, in order U> I""^
a concentrate richer in metal and freer from noxious ti^
than the crude material, or for extracting magnetic partio^ '^ ,
ores of bismuth, copper, gold, lead, or zinc, in which iron mins*'
play the part of troublesome refuse.
The machines for treating ores magnetically may becl»ffii=*"
as follows : —
Klod of UMblnh Man* of Innntor or lUcUoo. Voti <i(>«ta«
( a. Chaae VHoraiJ-
b. Conkling ... Wet
Kndlew bolt -j J; ^^Zx.
. Eessler
Drj.
/. LoTBtt-Flnney ... Wet.
o. BaU-Norton ("Monarch") ... Dry-
A. Bachanan
t. Friederichsse^n
)". King
it. WeDBtiSm
Deflection ... I. Edison
• Siviata dd atrvizio nuTurario nel 1889, Floience, 1894 P- '^
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DRESSING.
60 1
Sndleu Belts.— (o) The Chase separator* (Fig. 681) ha« two
endlees belts with magnets uudemeath. A, B are two revolving
iron rollers 4 inches in diameter and 3 feet long, converted
into magnets hy electric currents, and the space between them is
oconpied b; a stationary electro-magnet ; C is a driving pulley,
arid I> a tightening pulley. A cotton belt is made to travel
round these four pulleys in the direction shown by the arrow.
F is another magnetic roller, and O a driving pulley for the
second belt, travelling as shown.
The ore is fed on to the belt at the point E, and on arriving at
A the non-magnetio waste is thrown off by centrifugal force, whilst
the magnetic particles are attracted and held against the belt. All
the time they are passing from A to B they are subject to the in-
fluence of the electro-magnet, and owing to its construction they
come under the influence of a succession of poles alternating in
polarity. This causes the particles to turn over constantly and
BO free themselves from the non-magnetic or slightly magnetic
Fio. 681. Fio. 6Sa.
frTIIIIHMIIMll
grains, which fall into the compartment immediately below the
belt, destined for the middlings. The thoroughly magnetic par-
ticles travel with the belt to B, and as it moves up and the
influence of B becomes lees sensible, they are attracted by the
third magnetic roller F, and at lost leaping across the small inter-
vening space, they are carried op the belt to G, where they drop
off into the box containing the " heads." In making the little
jomp from B to F they still further free themselves from incom-
pletely magnetic middlings.
(£) The Coakling machine {Fig. 682) is an inclined endless
belt travelUng upon a roller at each end, with stationary electro-
magnets E £ under the upper half. The ore b fed on from a
hopper, and is subjected to the action of a stream of water ;
this washes down the non-magnetic particles, whilst the magnetite
adhering to the belt is carried over the top end. The Conkling
machine may therefore be looked upon as a Brunton separator
* SabllQ, " Hsgnetlc Sepaxation otlioa On," Eng. Min. Jour,, yol.]^,
189a, p. 663. This article gives recent Information on the anbject of
magnetic leparatlon, and baa farnished not only the accoont of the Ch*M
maobine, but also tooDj ot the dettuls conoemiiig some of the otberi. Sea
also JVant. Amer. latt. M.E., vol. zvii., 1S90, p. 728.
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6oi ORE AND STONE-MINING.
ID which the rich grains are held eg&inBt the bdt b; nugnw
attraction, and thus enabled to resist the force of thestnuicf
(e) Edison's second separator, which is used for tbe &iii
treatment of re-crushed ooncentratea, furnished by the deflediH!
machine (p. 606), is an end]«s belt placed rerticaUy , with eltriro-
niB^etsbehindoneeide; theyattract the fine particles of iiutg»l<«
andcause them to adhere sufficiently to be carried upwards, vhAK
the non-magnetic groins drop. The electro-nmgnete an unn^
BO that the particles travel over ma^ets alternating in opptfiu
polarity ; tlus causes, as in the Chase machine, a snceceifc (^
tumbles or somersaults, which set free the non-magnetic pim
and allow them to fall. The magnetite is carried up onrtbew
roller by buckets attached to one side of the belt.
((f) The Hoffmanseparator* (Fig. 683) is an endless belt imsiid
horizontally upon tbe ^
Fio. 683. drums A and B, provided "S^
two sets of magnete. Ti*
magnets C and also tb«
inside the drum B ha** ^
polee arranged altatu^'
When the ore is ted on to ih
belt from the hopper, it tn**
along over the magnets C,u'
is subject to magnelii: itw
tion varytug in amount, «■
cording to the distanw fw
the pole, and also in polarity. This action tends to makt '>^
magnetic particles group themselves into a layer resting ii"'"'
diately upon the belt, whilst the non-magnetic particles ^ "F-
the top. On arriving at B these latter are easily thrown off^
centrifugal force, and fall into the compartment E, whilst tw
maj^etic grains still cling to the belt. Those which u«ie^
completely magnetic drop atF; a better product is collecwl *
G, and a clean concentrate at H. The partitions, which wf'^
the waste and divide the orey shower into classes of vaiyingni^
ness, can be set so as to obtain any kind of classic cation wiuci'-'
most suitable to the ore under treatment.
A blast of air is drawn along the face of the belt in the oppJ^'''
direction to that of its travel, and helps to set free wy »*■
magnetic grains caught up between the others.
(«) Kessler,t of Oberlahnstein, is the inventor of a mww"
acting in a totally different manner (Fig. 684). It is » bnM
endless belt or chain, armed with a number of iron points, tn"''
ling over the two rollers A and B ; the former is an el"^
* "The Hoffman Magnetic Beparator," Eng. Itin. Jour., vol. 1u.>i^'
p. 680
i B.u.h. Z., 1891, p. 382.
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DRESSING.
603
magnet, the latter is made of wood. The stuff falls from the
hopper F Into the conveyor 0, which feeds it acroaa the whole
width of the cjrlinder A, and then drops into the curbed gutter G,
where the iron points are drawn through it as the belt revolves.
The points, while auder the influence of the electro-magnet A,
pick up the magnetic particles, and let them drop into the
compartment £ on losing their power, while the non-magnetic
particles fall at D. The partition between can be placed
Fio. 684.
Fia. 6S5.
in an; suitable poaition. This machine ha£ been used in Spain
for separating iron ore from calamine, after the former has been
made magnetic by a reducing calcination.
(/) Lovett'Finney machine (Kg. 685 ) in some respects resembles
the Conkling separator. It is a wet machine, consisting of an end-
less canvas l^lt travelling upon two drums, A and B, one of which,
A, has its outer surface made of baiB of iron ; these become magnets
of alternate polarity, as they are connected alternately witli the
iron discs forming the ends of the drum, which form the poles of
an electro-magnet. The ore is fed against the belt about half-way
up the magnetic drum A, and aa the belt revolves with the drum,
the magnetic pertidee are carried up, whilst the non-adherent
waste is washed off by a stream
of water. The concentrate is
conveyed over the pulley B into
a tank, and drops otf, as it ie no
longer subject to the attractive
force.
{g) Bolls.— In the Ball-Norton
machine (Fig. 686) the magnetic
particles are drawn against re-
volving drums made of paper pulp,
instead of being attracted to the surface of a canvas holt. There are
two drums,A and B,revolvinginthesamedirection,ineachofwhich
are arranged electro-m&gneta capable of holding magnetic particles
agaiustacertainportionof theundersurface. As usual, the magnets
are alternate in polarity. The ore is fed from a hopper C against
the roll A, the tails drop at once into D, and the adherent
magnetite travels along with the roll till it begins to leave the
Flo
686.
^
SI
l/\
w^
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6o4 ORE AND STONEillNlNG.
magnetia field ; tfaa oentrifngal fcxve now overpowen th
magnetic attractioo, throwing the gnina against the roO E
ThoM which are comfdetely magnetic attach themselveB to B, viii>
ore mixed with waste Ealls into the oompartanent E ; lastly, w ■
clean magnetite, on «»»pi"g from the infloenoe of the mkgm^
yields once mat* to the oemtarifngal force and is deposited U. F.
A strong enmnt of air is being const&ntly drawn through ti»
machine in the opposite direction to the trftvel of the ore uti
assutte in the cleaning.
(A) The Bnt^ianan separator * (Fig. 687) is made of two a.<-
iron rcdls, reroK-ing in opposite directions, supported on the ^l'i^
of an electro-magnet ; the two ttHh U-c~
Pia. 667. become the poles of a huge fa(»8«-sb'V
msgnet, and the magnetism is mc^'
strongly developed where they miK
closely approach each other. As the i.^
drops down between the rolls, the niif-
netic paiiiclea fly to them, and tn
carried along until they fall off at tif
■u* sides, when the oentrifogal force ovh^
powers the now diminishing magncix
attraction. The poor non-magnetic par
ticleit fall vertically.
(1) Zinc blende found mixed viit
chalybite at F^iedMichssegen is roasted
so as to convert the latter miaeral int^
magnetite, and thea treated in the machine shown in Figures c;.'
and 689. It is composed of a brass cylinder A, wit^ a number 1^
little ridgee S, pai&llel to the axis, and four sete of statioiuu^
electro-magnets B. T ifi the ore-hopper which supplies the fee^^
D : this is a sheet-iron tray, which is made to oecUlate by cul.'
upon a tittle shaft driven by the pulley Q. P is the main bej:
pulley upon H, the shaft of the brass drum, and £ is a pullr;
which drives Q by a belLf
A regular stream of fine ore is fed against the brass c^dinder be
the feeder S, and the grains of blende at once fall into the co3i-
partment Z ; the magnetic oxide of iron is held against tht
cylinder by the attraction of the electro-magnets, and is carrii^i
over by the little longitudinal ridges until it falls intx> the cdie-
partment F.
{f) King's X magnetic dreoBing machine works by the aid 0''
permanent magnets fixed upon a revolving dram. like otl^r
inventors he arrangee his magnets so that their poles aIt«ro>tr.
* Eng. MiK. Jaur^ vol. xirr., 1883, p. 133 ; voL iItU., 1S89, p. 542.
t BeUom, " Etat actael de la preparation mectuiiqiie dans la ^^t^^ a
Haiti et la Fnuse Eth^nane," Annait* dti JUiaa, ser. 8, voL xx. iSoi n. ;
B.K. A.2., i8qj, p. 37- • "^ .C
; £^fig4hird Attn. Rtp. B. Corn. Pti. Soe. Fahnonth, 1885, p. 44.
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DRESSING.
605
: and shake off axxy
ftnd he thus makes the grains tnmble (
looaely intermingled non-magnetic particles.
(it) TheWeustrOm*ieaSwediBli machine, which has been in use-
at Dannemora and other mines for some ysttiB (Fig. 690). It has a
stationaiy electro-magnet A, and a revolving armature barrel B^
oonaisting of a number of soft iron bars sepainted hy strips of
F10.68S.
Stalt'A*
wood. The electro-magnet lies on one side ot the centre of the-
barrel, so that the iron bars of the armature become magnetised
only during part of the revolution, C is a tray feeding the ore
on to the top of die barrel, D a shoot for the non-magnetic
particles, and B the shoot for the concentrate. The magnetic
grains adhere to the aoft iron bars when these are close to tb&
electro-magnet, and are carried past D as the barrel revolTes ;.
• E. if. /., vol. xlvt, 1888, p. 437. -fl. ". ft. Z, 1891, p. 178.
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6o6 OBE AND STONB-MINING.
as the ban recede from the eleotro-magnet, thay lose their pove
and iet the iron ore drop into £.
(I) Deflsotioii, — The simplect of nil magnetic sepaniton is oh
devised by Edison (Fig. 691).* It is based apoQ the fact that if >
thin sheet of finely crashed ore drops past a po'werfol dectn-
magnet, the magnetic particles will be drawn tomtrds it u-i
deflected from their direct downward path, whereas the ncc-
magnetic parUcles inll fall vertically. If a partition is fixed in 1
suitable manner, the concentrate falls on one side and the «*si
on the other. Diagrammatically the machine may be sbcm
thus : — A A represent the electro-magnets, B a hopper ddivRai:
the fine ore through a long narrow slit ; C is a tlun paititkic
The waste falls vertically into the compartment D, and the iici
ore into E.
Magnetic separators are ohieQy used for conoentrating lii
Fio. 690. FiQ. 691.
J
m
m
magnetite from ores that are too poor to go to the furuaoe in tt>
crude state ; and it has been propoeed to make brown hKniam«
magnetic by partial reduction at a low red-heat, but other q»«
have been mentioned in describing the various machines. For
instance, by the ordinary washing processes it is impossible to
separate chalybite with a density 37 to 3*9 from blende with >
density of 3-9 to 4*3. The aid of magnetism is here invtAsd wilt
success as already explained.
The N^amaqua Copper Company use King's magnetic sepaista
f<^ extracting the magnetite which b mixed with bomite acJ
chalcopyrite, in order to obtain a product richer in copper.
In a similar manner a magnetic concentrator of the BaU-Nrattx
type has been employed in Queensland for treating a mixed coii^
centrate of magnetite and bismnth ore, obtained by a wet-dressiL^
process. The percentage of bismuth is raised in this way from id
or 12 to 20 per cent.
On asmaUscale, the magnet is of service for extracting magnetic
* £. if. J., vdL liz. 1SS9, p. 479, and voL liiL 1892, p. 662.
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DBESSENG. 607
particles when washing samples of tin ore on the vanning afaovel,
or gold in the bat«a.
(6) FBIABIUTY. — Some minerala are more easily crumbled
and reduced to powder than others, and if the difference in
friability is great, it is powible after crushing to e9^ a separation
by a mere process of sifting. An instance of this rare method of
concentration occurs at the graphite mines near Faasau, in
Bavaria.* The softer kinds of mineral obtained from the mine are
ground in mills, when the thin greasy elastic platee of graphite
arrange themselvee parallelly to the surface of the stones, and
preserve their flat shape, while pieces of more brittle minerals are
reduced to the state of fine powder. The ground product is sifted
upon fine silk cloth, the dust poor in graphit« passes through the
fine holes, but the scales of graphite are left behind. As might
be supposed, the separation is not very thorougL
Biittengenbacht has separated blende from iron pyrites in a
somewhat similar way, the former mineral being much more easily
pulverised than the latter. He used a Yapart disintegrator to
treat a mixtare of blende and pyrites, in grains ^ inch to | inch
across, and by suitably regulating the speed, he was able to reduce
the blende to the state of fine sand without afiecting the pyrites
to any appreciable extent. The blende extracted by sifting con-
tained 5oto55 per cent, of sine, whilst the pyrites was almost free
from tlus metal.
The dressing <^ the plumUferous sandstone of Mechemich is
probably the most important instance of a difference in friability
affecting the method of treatment. The little concretions of
' galena and quartz are comparatively hard and the sandstone very
friable. The greater part of the stuff coming from the mine has
crumbled to the state of loose sand before it reaches the works,
so that the first comminution, which sets free the rich knoU, is
sufficiently effected by the mere handling, without the powerful
crushing machinery usually required for the preliminary treatment
of a lead ore.
III. PBOOXBSE8 DSPBITDZNQ UPOI7 CHBHICAIi
FBOFSBTISS.
<i) SOLITTZOir, ETAPOBATION, AND CBYSTAUiI-
SATION'. — Processes of this kind are employed by the miner in
some of the few cases where the mineral is soluble in water; aid
ia derived from oertain other solvents, such as benzine and hydro-
chloric acid.
The principal minerals soluble in water are bcn^x, nitrate of
Roda, potassium aalte, and common salt.
* Andr^, " Der osterreichiicho nnd bayeiiachs Graphitberghan,"
B. u.k. Z., iBgo, p. tjo.
t " Anfbereitimg von Blands and ScbwefelUea," B. u. b. Z., 1881,
p. 394-
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«o8 ORE AND 8T0NE-MINIXO.
The cmde bomz of Califorau* is groand mud thron: ir
a pan coatadnmg a boiling aaline solntioD, freqaentlj' the moo.
liquor from the second oTBtaUisatioD. The salts diaaolve ami ::
eand aiiiks to the bottom. The hot aolutioD is allowed to stui'i'
as to darif J, and ia then run off into pans and left to txxA bx i'-
to nine days, during which time the bonx cryBtalliBea out. r>
ctyetale obtained in this way are somewhat impure. Thrr i'^
refined by being disscdved and allowed to crystalHse a secotHl tb^
Nitrate of soda is treated on a larger scaJe.f The ea.W'
crushed into lumps about z inches acroes, is tipped into lis:
rectangular boiling tanks full of water, which are heated i" .
Hpiral 3-inch st«el pipe with steam at a pressure of 60 lbs. :
the square inch. The boiling is oarried on by Shanks' lixiroru
system, which causes a continual circulation of the lighter liq^.
to the other boiling tanks by following the denser and hai?
eolation. As soon as the solution is concentrated to no
Twaddell's hydrometer, it is allowed to settle for a ahon tar.
and is then drawn off to the crystallising tanks. The i^tk' -
the boiling tanks is again treated with water in order to eztiK ■
little nitrate which it still contains.
The crystals are shovelled out on to dr3ring floors and pot v.
in sacks for export.
The motber-liquor, which contains a little sodium todau. ;
added to the water used for dissolring a fresh stock of " nliciie,
and by repetitions of the process it becomes rich enon^ for \^-
extraction of the iodine ; this is precipitated by sodiom baBulphiti.
washed and pressed into cakee. The crude iodine so obtained ::
purified by sublimation.
The prindpal potassium salt of Stsasf urt is camallite, a hydnt^:
double chloride of potassium and msgneeium. Some of itistr»if;
on the spot in order to produce commercial chloride of potassimL,
The crude mineral, after being coarsely ground, is treated vi-j
hot water, and the strength of the solution is so arranged that od]
the chlorides of potassium and magnesium are dissolved ont. T:j-
residues are treated with cold water which dissolves out a?cL:
sodium chloride and leaves behind kieserite (bydrated magnesiic:
sulphate). This is passed through a fine sieve, moulded ini.'
blacks, and sold.
The solution of the chlorides of potassium and magn^un t
allowed to settle and cool, and three products are obtained fnc
it : (a) crystals of potassium chloride ; (S) mother- liquor ; (c) slimcj.
The crystals (a) still contain a little sodium chloride. Ths\ at
lowered into water in iron vessels and much of the sodium ch]or,i(
• C. Napier Hake, "An Acconnt of a Borax Lake In California." Jic
Sk. Cfc™. /nil., vol. Till., 1889, p. 854.
t Harvey, " Machinery foi the Manufacture of Nitrate of Soda at tlK
Bamirei Factotj, Northern Chili,'' l^oc Intt. C. E^ vol. Itt^^j .Kg, (•
p. 337- ' ^^'
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;: DRESSIlfG. 609
. - is dissolved out ; they now oontain 80 per cent, of potasuum chloride,
■ aad after being freed from moisture ia TheleD'a drier, they are
'. packed in bags and sold.
' The mother-liquor (b) is heated and gives crystals of artificial
. camallite, which are treated again in the same way as the native
].. mineral. On evaporation the final mother-liquor yields hydrated
'_ magnesium chloride.
''_ The slimes (e) are put into a, filter pfess, and the solid cakes
60 obtaiDed are calcined and sold as manure after being ground.
'They owe their fertilising value to some potassium chloride which
they still contain.
The evaporation of brine may be carried out naturally or
^ artificially. In Southern Europe, and in other countries where
tbe sun has sufficient power, sea-water led into shallow ponds
' gradually becomes concentrated enotigh to deposit salt. In
' Germany, weak brine is strengthened by allowing it to trickle
' down through brush-wood contained in huge frameworks of
timber. A great surface is thus exposed to the atmoephere with
- much evapoiative effect if the weather is dry.
In this country common salt is mostly obtained from brine
pumped up out of bore-holes or out of inundated salt mines.
.' After being allowed to settle, the brine is evaporated in large
sheet-iron pans heated by the flame of a coal fire passing under-
." neath along flues. Some of the pans in the Middlesbrough district
' are 70 feet long and 24 feet wide, with a depth of zo inches at
. the fire-end, and gradually lessening to 16 inches at tbe other.
^ In Obeshire, even larger pans may be seen, some, in fact, as much
; aa 100 feet lung by 45 feet wide. The heat of the fire gradually
drives off the water, and crusts of salt form on the surface ; they
', fall to the bottom and are shovelled out ; after being allowed to
; drain, the salt is ready for despatch to the alkali works.
; At Bex, in Switzerland, where fuel is dear and water-power
abundant, the brine in evaporated in a closed boiler, like a large
•■ ^g-ended steam boiler, heated from below ; the process of
, evaporation goes on continuously, brine being constantly pumped
in and salt being drawn off as it ia deposited.
f Benzine is employed in the exceptional cose of ozokerite for dis-
: solving out remnants of the mineral left in some of the residues.
Heavy spar stained by oxide of iron is " bleached " by sulphuric
- acid ; the mineral, after being crushed to the state of coarse
- powder, is put into lead-lined vats with dilute sulphuric acid,
' which is brought to the boiling-point hy the injection of steam.
Tbe acid dissolves the oxide and leaves white barytes ready for
grinding after it bos been dried.
Tin ore contaminated with copper ore may be freed from the
latter metal by hydrochloric acid ; the so-called " burnt leavings,"
that is to say the tiulings produced in washing the roasted
concentrates of tin ore, originally enveloped or accompanied by
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619 ORK AND STOHE-MINING.
Hulphides, are treated with hydrochloric add ; tito coppery eolulioD
IB led into pits, where the metal is precipitated hy iron.
(3) ATKOBFHEBIC WSATHXBZNG.— I mnet point ont
that though weathering often results from mere loss of wivt«r,
it may in other cases be caused by the chemical decompositioQ of
one of the minerals contained in the stuff under treatment. As
already stated, the boundaries between the Tariooa dressing pro-
cesses are not distinctly defined.
The crumbling-up of the diamond-bean ug rock under atmospheric
agencies plays an important part in the extraction of the gems,
and with no other mineral is a weathering action of this kind
carried oat on Bo large a scale or in such a systematio manner.
The floors devoted to this process at De Beers* mine occupy
some thoosands of acres. They are merely fairly level ground
from which the bush and grass have been removed, and which
has been rolled to make it hard. The ground is laid out in
rectanjtular sections, 600 yards long and 100 wide, and is enclosed
by high wire fences. Uain lines of rails on each side of tha
^>or8 and subsidiary portable linen serve to bring the trucks of
*' blue," which is tipped aad spread out so that a load, i^., 16
cubic feet or 1600 lbs., will occupy an area of 31 square feet.
After being left for some time, the " blue " is broken up by
means of picks into pieces not larger than 4 inches cube, and
is again left to dry for a further period, until most of the natural
water has evaporated. The ariiificial " diamond field " is then
watered, to aid the disintegration, and lastly harrowed and rolled ;
in fact, the miner endeavours to bring about the pulverisation
somewhat in the same way that the farmer prepares his land for
tillage.
The stuff is known at first aa " coarse blue ground," then as
" broken blue ground," and finally, after the rolli^, as " pulverised
blue ground,"
The length of time required for this disintegration depends not
only upon the atmoepherio conditions — that is to say, the season
of the year and the amount of rain — but also upon the mine
from which the blue is obtained. The blue from Kimberley
mine becomes sufficiently disintegrated in three months in
summer, whilst the De Beera blue requires double that time. It
is evident, therefore, that a very large stock of blue has to be
kept on the floors, if the washing machines are to be supplied
regularly.
The diamond is not the only gem which may be released from
ita matrix by disintegration under atmospheric agencice. The
gametiferous gravel of Bohemia f was at one time allowed
* Da Been Consolidated Miner, Ltnited, Second Aitnual Rrport for the
Year ended jirt MaTr:h, 1890, p. 18.
t BsTmoud, Di«ca»rion apon Kani'i paper on " Bohemiaa Oarnets,'*
Irani. Amgr. Intl. if. B., voL xxl., 1891, p Z49.
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to weather for three months on the surface, in order to fit it for
the subsequent washing prooees.
Phosphate of lime occurring in the form of nodules in cla; is
treated in a like manner. The phosphate dug from open pits in
the Lias in the department of the Haute-SaSne * is left exposed
to the air often all the winter ; a part of the earthy matter falU
off, and the nodules have simply to be screened d^, in order to
separate a large portion of the clay with which they were
only originally mixed. Again, in the Yosgee there is a photi-
phatio bed of the same geologioal age, consisting of soft noduliw
forming only -^ or ^ of the bed of brown clay by which they
are enveloped. The stuff is spread out on the fields and raked
over occasionally. The clay crumbles off, and at the same time
the nodules harden from losing their moisture; they are then
picked out by hand.
"Nodules of clay ironstone are freed from shale in a similar
way ; and ores of iron more or less contaminated with iron or
copper pyrites gradually have a portion of their sulphur washed
out in the form of soluble sulphates, if exposed for a sufficient
time to the action of air and rain.
Fire-clay is found to be better suited for making bricks after
weathering for some months, than when first raised from under-
ground.
(3) CAIXJINATIOH OB BOASTING.— The object of
calcination or roasting may be :
a. To effect a change in the chemical composition of a valuable
mineral, and so produce either an ordinary article of commerce or
one that is more readily Ealeabte than the raw material.
b. To effect a change in the chemical composition of some 4f
the sahetancee accompanying a valuable mineral, and so get rid
of them partially or render them more easily separable by other
processes.
The oommoneet example which can be cited is burning
limestone ; the action of heat is made use of to drive off
the carbonic acid and leave quicklime. Another instance ia
furnished by olay ironstone, or any ore in which the iron occurs
mainly in the form of carbonate. Simple exposure to heat con-
verts ferrous carbonate into magnetic oxide ; the former contains
48 per cent, of iron, the latter 72 per cent. ; consequently, if the
ore has to be sent to a distance there is a saving in freight,
besides which the ore is more acceptable to the ironmaster for his
fumacee.
Qypsum is cal<nned in order to expel the water chemically
combined with it, and convert it into plaster of Paris.
With the ores of arsenic, it is the valuable ingredient which is
driven off. Mispickel and other arsenical ores are roasted at
* Ulatulique tUFindutlrU minirale en Franee ft en Algim ea 18S6, Fails,
1888, p. 36S and p. 283. . .
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6i3 ORE AND STONE-MININO.
minea in order to produce ftnenious acid, which is cdlectcJ-
«peciftl flucB.
Ores of copper ara sometimes calcined at mines, vi& i.-
object of Qztracting the arsenic before sale to the Bmettn^ ■.
would pa; nothing for this latter metal and prefer its abeoKv.
Galcmation is resorted to in the ease of some iron onis in '?r'^--
to get rid of the sulphur, due to intermixed iron pyrites or f^m:-
tine, and so free the ore from an element which the smeltA- iList-
Thus in Northamptonshire the undecomposed greenish iaa.^ i:
the bed are picked out on account of the sulphur they cocx:
and put aside. When a sufficient quantity has accumDliirii. .
heap is made with a little coal and fired ; the ore loaes near j i.
ite sulphur in the burning and ia thus fitted for the bhi.
furnace.
Auriferous ores are roasted in some instances for the pon-'--
of liberating the gold which is so enveloped in sulphides w-
eulpharsenides, such as iron pyritee and mispickel, as to be nu^-'
with difficulty by mercury.
Partially ooncentrated tin on (whiu) is roasted In order -
convert iron pyrites and mispickel into pulverulent oxideG «'u -
can easily be eepaiated by washing. Again, tin oto U occasimj-
associated with a considerable amount of wolfivm, «:::-
approaches it so closely in density that separation by washic;: '
impoesible. The mixed concentrate obtained by the ordii^'
dressing processes, consisting of cassiterite mixed with wolfri;
is roosted with carbonate or sulphate of soda; soluble tun^<-
of soda is produced, which is dissolved out by water, \a^s.
behind the insoluble cassiterite fit for the smelter.
lastly, we may take the case of zinc ore. Blake * rutdof "'
separation of blende from marcasite commerciaily possible. '■'■
roasting the mixed minerals at a temperature snfGcieiit to eoh^-.:
the latter into oxide, while the former remains unchanged^ ti-
diflerence in specific gravity is then sufficient to allow the ct:
nary washing processes to take eSect. Stoithsonite mixed *:'
limoDite4' is roasted with coal in order to reduce the ferric ce:.'
to the state of magnetic oxide, and thus render it separaU« i': ■
magnetic process.
It now remains to be seen how calcination is carried ou'
Minerals may be burnt in heaps, in kilns and in furnaces.
Clay ironstone is usually burnt in heaps with the additioD ol ■
little coal ; but one variety, black band ironstone, otmtaic -
sufficient amount of carbonaceous matter to bum of itself.
The spathose ore underlying the limonite {" rubio ") at Bii't-
is now being successfully <»lciQed on a very large scs^e previ'>^-
to shipment. According to Mr. Windsor Riohu^s,^: the rsw<^r
" "The Sepamtion of Zinc Blaiide from Iron Pyrites." TVaiu. J^ ■
Jntt. M. E., vol. zsil., 1893-4 > '^A {^) Pa;ne in the Diacminan.
i "Fnm. AddieM to I. and S. laat.," ColL Guard^ vol. Izr., lS93,p.^"
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SBESSING. 613
coDtains 43 per cent, of iron and 35 per cent, of carbonic acid,
whibt the calcined ore gives 58 per cent, of iron and only 2 par
cent, of moisture. One of the la^ kilns gets through 1500 t<ma
of raw ore weekly.
The conunoneet example of calciuatioa in kilos is making
lime. At large works tbe time-honoured semi-spheroidal kiln
with intermittent action is often supplanted by the Hofmann
kiln, in which the proceeses of cbarging, burning, and discharging
go on continuously.
Some of the baking ovens used for converting gypsum into
plaster of Paris, by the siuiple expulsion of the water of combi-
nation, are cylincb^cal brick kilns so arranged that the flame
nowhere comes in contact with the mineral. The fireplace is in
the centre, and the hot gasee are drawn down flues into an
annular arched passage all round the bottom of the kiln, and
then ascend through the charge by means of a number of
cast-iron pipea. The kiln is covered by a brick dome over
which comes a conical hood or chimney.
In making Parian cement from gypsum a different oven is
employed, in which a central coke fire sends out its hot gases
directly on to the charge itself.
The furnaces used by the miner are usually of the reverberatory
type, in which the fl^me plays into the space containing the
charge ; the bed may be statitmary mr revolving. The two most
frequently employed in Cornwall and Devon, for roasting the
ores of arsenic, copper and tin, are Brunton's calciner and
Hockin and Oxland'e calciner. The former (Fig. 693) * has a
revolving circular bed about 10 feet in diameter, supported by a
vertical shaft, which is made to revolve slowly by any convenient
source of power, whilst the flames of two fireplaces at the sides
play upon it and produce the requisite amount of heat. Depend-
ing from cast-iron frames &zed in the roof of the furnace, are
three sets of knives or teeth, inclined in such a manner as to
shift the ore gndually from the centre, where it is fed on,
towards the circumference, where it is discharged. The action of
heat in the presence of atmospheric oxygen converts the sulphur
and arsenic into sulphurous and aisenious acids, which escape
with the other hot gases, and are led into long condensing flues.
These are brick or stone passages high enough for a man to
stand upright, with partial partitions so arranged as to make
the hot gases take a tortuous path. There are large openings
on one side for drawing out the arsenical aoot at intervals.
During the actual calcination these doors or manholes are closed
by sheets of iron carefully luted with clay.
The Hockin and Oxland calciner is not unlike the Bruckner
furnace used in the United States, as it is a revolving cylinder
* HenderaoQ. Op, eit. .
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6i4 ORE AND STONB-MININO.
lined with firs-brick. Figui'es 693 and 694* show the construction
of such a furnace. A is the cylinder Uaed with fire-brick, set at a
slight inclination and supported on rollere. ItismadetoreTolveat
the rate <^ six to eight revolutions per hour ; B is a screw which
Fia, 691.
brings down a regalar supply c^ ore from a hopper. The ot«
travels along very gradually in the direction of the arrow and
finally drops into the chamber C. I> is the fireplace opening into
the lower end of the cylinder, and £1 is the beginning of the fluee,
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DRESSING. 615
on which the arseuious add is cDndensed and through which the
sulphurous acid passeH on its way to the chimney. The longi-
tudinal ribs of fire-brick, extending two-thirds of the length of
the furnace from the lower end, serve to lift up the charge and
Jet it faU, BO as to expose new surfaces to the action of the air.
One of these caldners used some years ago at Devon Great
CoDBols mine was simply an old boiler tube, 30 feet long by 3 feet
6 inches in diameter, lined with 4j-inch fire-brick, so that the
clear diameter inside was 2 feet 9 inches. Another was made of
an old boiler 5 feet in diameter. The inclination was 1 in 24.
Fio. 693.
7 M ernes
Some of the calamine at Monteponi, which has been concen-
trated by the ordinary wet methods until it contains 20 per cent,
of zinc, is atiU much mixed with oxide of iron and dolomite. Two
per cent, of coal are added, end the ore is passed through the
rotary furnace, 43 feet (13 m.) long, working continuously like
the Hockin and Oxland calciner ; the iron is thus brought to the
fitato of magnetic oxide. On leaving the furnace the ore is
moistened with water, which causes the calcined dolomite to foil
to powder. It in next treated on screens, and the various cate-
gories produced are sent separately to a magnetic concentrator.*
^ p. 3(1 ; and Eng. Min,
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6i6 OEE AND STONE-MINING.
(4) CBHBlTFATIOir. — The precipitation of copper by iron
may fairly be regarded as coming within the province of the
miner, when the solntion flows natorally out of an adit level
or is pumped up from underground, or when it is obtained
artificially as a by-product in tin-dressing. On the other hnnd,
the metallurgist may fairly claim such operatiooa ns those
conducted on a huge scale at Bio Tinto, where the cupreous
solution is mainly prodaced by leaching the ore which has been
burnt in heaps, or a mixture cj bomt ore and raw ore. However,
as in other cases, the line of demarcation between the two do-
mains is an arbitrary one, and on this account it is advisable that
the mining student should be well grounded in metallurgy.
The famous old Farys mine in Anglesey, now shorn of its glory
owing to the low price of copper, aCTonls the most important ,
example of cementation carried on at a mine in this countiy.
Coppery water is pumped out of the mine, and is led into
briok~lined pits containing scrap-iron. The iron ie raked over
from time to time, and eventually the old pots, kettles, shovels,
meat-tins, <tc., pass into solution, while the copper is precipi-
tated. As might be imagined, when one looks at the heterogeneous
mixture of articles constituting the ecrap-iron thrown into the
pits, the precipitate b very impure and contains only some so to
30 per cent, of metallic copper.
The iron used is not lost ; the ferruginous solution running
away from the precipitating pits is led into large pools, and
there exposed to the aiction of air and rain. The dissolved iron
gradually passes to a higher state of oxidation, producing in-
soluble ochre, and little by little a deposit of this substAnce forms
upon the bottom of the big ponds. According to the strength oE
the irony solution supplied, the ponds are run dry and cleared
out once in every two or three months. Wind and rain aid the
process of oxidation.
(5) AUALOAUATIOIT.— Two metals, gold and silver, are
extracted from their ores by amalgamation, that is to say, by
processes based upon their affinity for mercury ; and here we are
once more on the borderland between mining and metallurgical
practice. In the case of sOver ores, the processes are often
complex and require the precious metal to be brought into the
state of chloride before amalgamation is possible ; besides which
they are frequently carried on at works which do not belong to the
mining company. I therefore consider that the miner would be
encroaching upon the territory of his neighbour by interfering in
this instance, whilst, on the other hand, with gold the process is
generally simple, and the ore goes straight from the shaft or
adit to crushing and amalgamating works owned by the same
company as the mine.
The amalgamation of gold takes place by mere contact, either
when the particles touch the mercury as they slide or roll along.
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DRESSING. 617
in a current of water, or when they are in eome way mechanically
rubbed against it.
An instance of the first kind of action has already been given
in the description of hydraulic miuingin Chapter YI^ and another
may be taken from the ordinary stamping mill of most gold
mines in which auriferous quartz is being treated. The pulp
diechai^ed through the grates of the mortar-box is allowed tc
flow over an inclined table, covered with a sheet of copper which
has been amalgamated. The surface of the copper plate is first
very carefully scoured, then cleaned with a solution ot cyanide of
potassium, and finally rubbed with mercui^ and a little aal-
ammoniac. The bright silvery surface is then capable of picking
up the little particles of gold in the pulp and retaining them in
the form of a coating of amalgam, which is naturally thickest
where the pulp first comes upon the table. When a sufficient
thickness has accumulated, the amalgam is scraped oS, washed,
mixed with a little fresh quicksilver, washed with water, and
finally squeesed through canvas or chamois leather. The bard
■nialgmn so obtained is retorted.
Various devices are in use for making the little particles of
gold turn over from time to time and so expose fresh surfaces to
the quicksilver, in order to increase the chancee of such intimate
contact as wilt ensure amalgamation. Sometimes steps ore made
in the tables, giving the thin stream of pulp a Uttle drop, some-
times the tables are shaken, whilst in the Hungarian mill the
pulp flows over the surface (d a bath of mercury, the surface of
which is lightly skimmed by revolving iron knives.
Amalgamation will not take place unless the two metals are
bright and clean ; any slight film upon the mercury, such as
is produced by grease or tarnisb, prevents contact, and the little
particle of gold rolls or slides down over the plate, just aK it
would do on a plain sheet of copper, and is l^ble to escape.
The greatest care has therefore to be taken to keep the
amalgamated plates clean, and from time to time any tarnish
may oe removed by brushing them with a solution of cyanide
of potassium. Other means of keeping quicksilver bright are
tbe addition of a little sodium amalgam, or the production of
nascent hydrogen upon the surface of a mercury bath by the
passage of a current of electricity. This is the principle of
MoUoy's amalgamator, and that invented by Chaster and Beck. It
is evident from ezperimente, when the mercury covered with water
is connected to the negative pole of a dynamo, and lead plates
forming the anode are connected to tbe positive pole, that the
disengagement of hydn^n does keep the bath constantly bright
and lively, and fully entitles the metal to its familiar name
" quicksilver." Under these circumstances it takes bold of the
gold more readily, but the process does not appear to have gone
beyond the experimental stage at present.
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6i8 ORE AND STONE-MINING.
CoDsidving the ease with which amalgam&tion is impeded
or prevented by a flimsy coating upon the mercury or upon the
gold, it is not surprising that rubbing of some kind ahoold have
been tried in order to brigbtea the surfaces of the two metals
and so secure perfect contact. It seems probable that when gold
was worked by the Romans in the Alps, the precious metal was
extracted by rubbing the ore to powder with water and mercury
upon slabs of gneiss by stone mullers. Subsequently, no doubt, the
quern was pressed into the service of the gold-miner, and by adding
a rude horizontel water-wheel to the quern, the hardy Pied montese
miners developed their molin^So, or small mill, by means of which
large quantities of gold have been obtained. Proceeding one step
further, we have the arrastra, the most perfect form of which can
probably be seen in Italy, and substituting iron and steel for
stone we have the various pans. All these tmlls performa doable
service ; they not only break i^ the ore and set free the minute
particles of gold, but they at the same time scour the gold,
make it bright and rub it against the quicksilver. Probably in
many cases the gold makes a streak upon the bed, just as it
would do if rubbed upon a jew-eller's touchstone, and so gives a
dean bright surface with which the mercury at once amalgamates.
The mills may also be worked as concentrators, for if a stream of
water is run through them while they are being driven slowly, the
light particles are carried off, and the heavy metallic sulphides lie
at the bottom in contact with the mercury, ready to give up the gold
they contain as soon as they are crushed fine enough to liberate
it. The heat developed by the friction of the muller is consider-
able and may aeaist the process of amalgamation, and indeed it may
explain how it is possible to extract So percent, of the gold from
ores containing lo to 20 per cent, of iron pyrites by simple amal-
gamation in arrastras. The arrastra is a more suitable
amalgamator for such ores than the copper plate, but it is a
dow grinder and it causes a large loss in quicksilver when raw
ore is treated by it. Various other mills are used for the same
purpose.
APFIiICATIOn OF FBOCES8EB.— Having now passed
in review the various mechanical, physical, and chemical processes
which are employed by the miner in preparing his minerals for
sale, it remains to say a few words upon the manner in which
they are applied in different cases. Space will not admit moca
than an outline, nor is it necessary in a general taxt-book to
enter deeply into details.
For the sake of convenience the various minerals will be taken
in alphabetical (nrder.
Amber. — The lumps are separated by washing from the endoe-
ing sand, and are sorted according to colour and sixe. The small
[neoee are braated in a steam hath at a temperature of 1 50° with
certain re-agents in order to rumove the dark rind, and the clear
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DBESSING. 619
kernels vhich remain are melted ap tog;ether and sold to the
vamisl) merchantB,
Arsenio. — Amnioua odd is obtained by roasting and aablima-
tion. The crude arsenic resulting from the treatment of tin
" white " is usually of & dirty grey colour owing to the ad-
mixture of solid carbonaceous particles deposited by the smoke ;
it is spoken of as " aiseoical soot," and is sold by the miner to
works where it can be purified by being re-sublimed.
At some mines, however, which yield large quantities of mis-
pickal, the final purification is performed on the spot, and white
sublimed arsenic and arsenical glass are prepared by re-eublima-
tion, put into barrels and sent out into commerce.
Asbestoa.— The dressing of the asbestos (chijeolite) of Canada
is amply a process of cobbing — i.e., the separation of the valuable
mineral from the endosiiig serpentine by well-directed blows of
the hammer,
Aeplult. — The crude Trinidad pitch is purified or refined on
the island by melting it in iron "^dr and allowing the earthy
matter to fall to tbe bottom. In France the process is some-
what different : the crude pitch is boiled with a heavy tar oil
obtained from the distillation of shale, in the proportion of 9
of pitch to 4 of tar oil. The 30 per cent, of watOT in the pitch is
driven off and & small amount of earthy matter is deposited, but
the refined pitch, consisting of the two ingredients which were
mixed, still contains a large percentage of clay.
Bituminous sandstone * is made to yield up its pitch by melting
with water. The sandstone is broken up into lamps about 3
inches across, thrown into cauldrons of boiling water, and stirred
for an hour. The bitumen melts and rises to the top, whilst
the sand falls to the bottom. Tbe bitumen is skimmed off, though
it is by no means free from sand, if the original sandstone was fine-
grainwi. It is then re-melted and the sand allowed to sink;
the liquid bitumen is drawn off and allowed to cool in moulds,
but the sandy deposit at the bottom still contains a good deal of
pitch which cannot profitably be separated.
The treatment of the bituminous limestone of Soyssel has
already been described in the general port of this chapter.
. Barytes. — The principal prooesaes in preparing barytes for
the market are drying and grinding.
The barytee coming from the mine is washed and picked, and
pieces intermixed with rock are cleaned by cobbing. Tbe lumps
are dried upon a tiled floor heated by flues underneath, and are
then crushed, either by rolls or an edge-runner, to a coarse
powder, which is twice ground in mills like flour-milts. French
burr stones are preferred. The second grinding yields a powder
as fine as flour, which is put up into barrels ready for sale.
■ Malo, L'AMphdte, Paris, iSSS, p. 68.
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ORE AND STONE-MINING.
Iron-shuned barytea ifi " bleached " by acid, ax already ez-
Borax. — The earth obtained at the borax lake, CaJifoinia, is
ground, and then dissolved in wat«r brought to the boiling
point in targe iron vats by injecting steam. The contents are
allowed to settle, and the clear solution, containing the carbonate,
sulphate, chloride, and borate of Bodium, is dr^wn off into pans
and allowed to cool. The borax is the first to cryfttallise out, and
the crystals ore collected and sold, or are re-diaaolved ; this second
solution furnishes, on crystallisiDg, the refined borax of com-
niMce.*
Boiio Add. — The solution of boric acid, obtained in Tus-
cany by passing natural steam-pufis (ao^oni) through water, is
evaporated either by the heat of some of these soffioni, or
artificially, until the gypsum and other impurities separate;
the liquid is drawn off and the acid is allowed to crystallise
out.
Carbonio Acid. — If not at onoe piped off to white lead or soda
works, carbonic acid is compressed and sold in the liquid state.
Clay. — Common clays are used on the spot, and made into
bricks, tiles, or dtain-pipes. The potter's clay of Devonshire
is sent away in cubical lumps just as they come from the pit,
hut the china day is obtained by a true dressing process. The
stream of water running down the side of the openwork, and
carrying with it all the ingrodiente of the decomposed granite, ia
ledintoapit where the coarse particles of quai-tzBettle,t whilst the
clayey water is conducted into long channels in which fine sand and
mica are deposited gradually. Lastly, the milky stream reaches,
circular pits, 20 to 40 feet in diameter, and 6 to ao feet deep,
drops its kaolin, and passes off as almost clean water. The
creamy deposit is dried in the manner already described (Fig. 676),
and the china clay of commerce is the result.
Fuller's earth is also a clay which has to be dressed before being
sent into the market. The processes to which it is usually sub-
jected are drying, sifting, and grinding.
The clay coming from the pit« is dried in kilns (Fig. 677) and
sifted by hand to take cut the fine, if the customer insists upon.
having nothing but lumps. The dry lumps are put up into sacks,
and the small is sifted again. The very fine, below ^ inch, is
thrown away, and the coanier part is ground to fine flour in an
Askham mill, and so sold.
In addition to this dry dressing, some of the clay is ground in
an edge-runner, run into settling tanks, and dried much in the
same way as china clay.
* Napier Hake, " An Account of & Borax Lake Id Callfonila," Jour. &e,
Chan. Ind., vol. viil,, 1889, p. 856; E. L. Fleming, "Boras," Chem. 2ft«t,
voL IxlU., iSgi.p. 74.
t CoUiUB, 'Ibe HentbVTToa Ormile Ditlriet, Tmio, 1878, p, 1$.
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SRESSIN^Q. 621
Copper Ore.'^The ores of copper are bo different that no
general scheme of treatment saitable to all of them can be pre-
Bcribed. Thus, for instance, the copper shale of Mantifeld ie
merely picked at the mine before going to the smelting works,
which receive an ore containiag only 3 to 3 per cent, of metal. At
the Lake Superior mines concentration by water can be carried
to such a pitch that the " barrel copper " leaving the dressing
establishments often has more than 70 per cent of metal.
Hand-picking is generally an important part of the dressing
when the ore consists largely of a mineral like chalcopyrite,
because it is easily crushed to powder liable to ba carried away by
water in washing. At the Rio Tinto mines t the following are
the principal varieties separated by picking :
a. Kioh ore with 5 or 6 per cent, of copper, which la smelted on the
b. Lamp ore with 2 to 3 per cam of copper, which Ii ezpoitad.
c Lnmp ore with 2 per oeat. of copper, which is burnt in heaps on
the spot.
d. Fine ore, which !■ added to the bnmt ore, so that its copper
ma; be Kradnally rendered solublB.
«. Qoartzose ore, which la retained for the fninaoes.
When copper pyrites occurs coarsely intermixed with quarts and
other earthy minerals, the dreesiug naually begins with hand-picking
and crushing by rolls ; the coarser grains are jigged, and the finest
particles are cleaned and rendered rich enough for sale, by buddies,
frames, revolving tables, or endless bolts. Intermediate products
made up of ore and waste have to be re-crasbed before a complete
separation is possible.
At the Lake Superico: mines, where the mineral is native
copper, the treatment is different. The rock from the mine is
stamped by huge Ball orLeavitt stamps imtil it will pass through
holes of ^ inch, and the copper-bearing stream is delivered
into upward current sepaiaton, which make five classes; the
four coarsest sizes are ti-eated on Collom jigs, and the fifth upon
revolving tables.
DiamondB. — The dressing of the diamond-bearing rock of
South Africa X i^y be divided into the following separate
operations :
a. Natural disintegration, under atmospheric agendes, aided by
watering, rolling and harrowing,
* Egleston, " Copper Dressing In I^e Superior," MeU^vrgusai StvUie,
NewTork, vol. iL, 1878-
HendersoD, " On the Methods generall; adopted in Cornwall in Dressing
Tin and Copper Ores," Proe. liitl. C. E., vol. ivii., 1857-58, p, 106.
Bathbone, " On Copper Hiniug in the Lake Baperior District," iW.
Imt. Mech. Evg., 1887, p. 86.
t Collina " <)n the Geology ot the Rio Unto If Inea," Q. J. Oed. Son., voL
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6aa ORE AND STONE-MININti.
b. Screening in a. Tevolving aoraen, wi^ hides i inch hy i inch,
or I inch by t^, which take out co&rse lumps ; these are returned
to the depositing floors to undei^ the weathering process a littJe
longer.
c. Washing the fine in rotary pans, which' separate clean giarel
from the fine sand and mud; the latter flow ioto another similar
washer, where the process is repeated in case any diamonds should
have escaped in the overflow from the first.
d. Screeninjf the clean gravel through a cylindrical sieve, with
round holes varying from ^ inch to g inch in diameter, "T^l"iig
in all five sizes. The largest grains discarded by the sieve are
picked at once,
e. Treatment in a " pulsator," which is simply a jig with con-
tinuous feed and discharge like the H&rtz jigs. The bed is formed
of leaden bullets. A conoentrate, containing ihe diamonds,
passes through the bed, and refuse goes over the edge of the
jig-
/. Picking out the diamonds by hand, first by white men when
the gravel is wet, and then by native convicts when it is dry.
The operation of picking is rapeated as often as enough diamonds
are found to repay the cost of the labour.
Flint and Chert. — Ilints are trimmed into square-faced
lumps for building purposes, or aro split and trimmed into
gun-flints. Chert is trimmed hy hammering into blocks for use
in the potteries.
Gold. — The precious metal may be extracted from simple sand
and gravel by mere washing, or by washing com.bined with amal-
gamation. Hydraulic mining affords an example of the latter
method. When the gold is enclosed in hard rock such as quartz,
or occurs in a hard tightly cemented conglomerate, the auriferous
stone has to be crushed in order to set the metal free.
The crushing is most often eflected by a stonebreaker, followed
by stamps, and the pulp is run over amalgamated copper plates.
Mercury is often added in the battery so as to catch the coarse
gold at once. The amalgam scraped off the plates and taken out
of the battery-box is cleaned and retorted, giving spongy gold,
which is melted in crucibles and cast into bars. If the ore
contains much pyrites or other heavy metallic sulphides, the stuff
leaving the amalgamated plates is t^en to a dressing machine of
some kind, such as a Frue-vanner, which furnishes a concentrate
consisting largely of metallic sulphides, more commonly known to
miners by their older name of " sulphurots." These are sui« to
contain gold, and they are further treated in various ways: by
direct amalgamation in pans, which means a still finer grinding,
to liberate more of the fine particles of gold, by smelting, by
ehlorination, or by the cyanide process.
Gold is also extracted by grinding up the ore in mills or arras-
tras with water and a little mercury. Excellent results have
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DBESSING. 623
been obtained id Italy hy this method, even with highly pyritic
ores.
It is very necessary that the miner should recollect that gold
does not always exist in the same state in the ore, and that the
value of the ore depends not only upon the amount of metal in
it, but also upon the ease with which it is extracted. A mere
assay gives information upon the fint point only. It tells how
much gold there is per ton, but it does not say whether the
metal is in the native state, or whether it is combined with some
other element which may render extraction by amalgamation
quite impossible. Even when the gold is all native, the size of
the particles varies considerably, and they may or may not be
wrapped up in iron pyrites or other metallic sulphides. Con-
sequently it is futile to suppose that all gold ores can be treated
by one and the same method.
Graphite. — The graphite of Ceylon is first picked at the
mine, and then despatched to Colombo to undergo the processes of
cobbing, picking, and screening. Men and women, using a tool
like a Httle axe, chip off the waste material from the lumps, and
sift the small fragments upon slightly inclined screens made of
sheet-iron. They also clean the Imnps with brushes made of
cocoa-nut husks. In this manner four different kinds of graphite
are produced — viz., " lai^e lumps," pieces about as big as the fist
or la[|;eF ; " ordinary lumps," about the size of walnuts ; " chips,"
about the size of grains of wheat ; and "dust," which includes
everything smaller. The graphite is now ready to be barrelled
for export.
One mode of concentrating certain kinds of graphite has been
mentioned as an instance of a method depending upon differences
of friability ; but in addition to these dry processes, graphite is
also dressed by the aid of water. In Uoravls and Bohemia
graphite is found in gneiss, and may be intermixed with lime-
stone, quartz, iron pyrites, garnets and hornblende. Bock of this
kind is pulverised by grinding in mills, or by stamping, and the
pulp is made to flow into rectangular wooden boxes in which the
coarser particles and port of the rock and pyrites are deposited.
The graphite-bearing water posses on into a number of long
rectangular wooden troughs (^jtm, atrift, or itrakee, Cornwall), in
which the graphite deposits itself gradually, whilst clean water
flows out M the last trough. The first trough has the worst
graphite, and the last the best quality of the mineral. The
deposit is dug oat, pressed in filter presses, and the resulting
cakes are dried in stovee.*
Qypsmn.-^The preparation of gypsum for the market resolves
* Andrte, " Der osterreichiHche nnd bayeriaohe Grapbftbergban." S. u.
h. Z.. 1890, p. 369.
Schaaenstein, DenicbuiA de» GtlerreUAiichtH Berg- unii SOtteiuiitttat,
Tieona, 1873, p. 116.
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6z4 ORE ATID SXONE-MINING.
itself into picking, breftldog, bumiug ftud gnnding ; or where the
gypsum IB required for other purpoeee than cement m&kdDg, the
burning or baking ia omitted.
In Sussex the \raggona coming from the mine are tipped on to a
floor, the large lumps are broken up with a sledge hammer, and any
pieces much mixed with worthless rock are picked out as useless.
The r^nainder is sent to a etonehreaker, and the broken lumps go
either to a b^ing oven to be made into plaster, to a burning
oven if Parian cement is required, or to agrinding apparatus if the
gypsum is sold to manure merchants.
After burning or baking, the product is ground, first by toothed
rolls and then under edge-runners. It is now token up by an
elevator, put through a tine revolving screen, and is drawn oS
into sacks.
Iron. — With a substance of small intrinsic value like iron ore,
the methods of dressing must be inexpensive if they are to be
commercially profitable ; and at the present time it may be said
that most of the iron of commerce is obtained from ores which
go direct to the smelter without any preparation beyond picking
out refuse underground. A few instances of cakjnation have
already been noted, and also the separation of fine ore by a
sieve. Iron ore is sometimes washed in order to get rid of
adherent clay, and at the mines of Korth I^ncashire some of
the hcematite, mixed with clay and siliceous matter, is made fit
for the blast furnace l^ crushing and jigging.*
The same line of treatment is pursued in the dressing works of
the Chateaugay Ore and Iron Company, at Lyon Mountain, N.Y.
The mine produces magnetic iron ore, the richer parts of which
are picked out, whilst the leaner parts, consisting of grains of
magnetite disseminated through gneiss, go to the mills for con-
centration. This mixed ore is crushed by BJake breakers, and after
BcreenixLg is treated in Conkling jigs.f
Hsmatite for fettling puddling furnaces is ground under edge-
runners, and that which is used for making castings malleable is
carefully screened. Special qualities are picked out for these
purposes.
In this country the supply of magnetic iron ore is insignificant,
and consequently we cannot show examples r^ concentrating by
the aid of magnetism, such as may be found in Sweden and the
United States, where this method is occupying much attention,
as may be inferred from the descriptions of magnetic separators
just given.
Ii^d.^ — A few mines produce lumps of galena so pure that
• J. G. Lawn.
t Rnttmann, *' Concentrating Magnetite with the ConkliDg Jig at Lyon
. Moontain, N.Y.," Tram. Amer. IrtMt. M.E., vol xvL, 18S8, p. 609 ; and
E. M. J., vol xlvi., i88«, p. 870.
i Vol detaili consult BeUom, " Etat aotnel de la prSpaiatioa mteanlqne
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DRESSING. 625
they merely require washing in order to be ready for sale to the
smelter or the potter.
Much of the leftd ore from veins Is dresead by crushing,
sizing and jigging ; the particles under i mm., or at all events
under i mm., are treated by revolving tables, percussion tables,
endleea belts, or buddies.
The crushing is done first by a stonebreaker and then by rolls.
Blende is often associated with galena, but owing to the difference
in their specific gravities, a separation can be made by the
appliances just mentioned. Products obtained from the jigs
consisting of mixed minerals have to be re-crushed, and then
treated once more l^ machinery similar to that used for the
(niginal ore.*
The soft lead-bearing sandstone of Meahemich t crumbles to
pieces so easily, that by the time it reaches the dressing establish-
ment, after having fallen down in the underground chambers and
dropped through shoots into the waggons, most of it is in a fit state
for the concentrating machinery. The works are specially designed
for treating very large quantities of poor ore consisting almost
entirety of galena and quarts sand ; their main feature is the use
of the siphon separate (p. 57S), by which a very large pro-
portion of the stuff is at once concentrated into clean concretions
{KrtoUen) containing about 33 per cent, of lead. This concentrate
goes to another establishment, where it is stamped and passed
through siphon separators, jigs, revolving tables and round
buddies, in order to separate lead ore fit for the furnaces.
Manganese. — The only preparation of the Welsh manganese
ore is separating the fine ore under ^ inch, by sifting in the mine,
and picking out of any pieces of waste or very poor rock.
The Devonshire ore, which conmsted largely of pailomelane,
was washed and picked, and the " smalls " were jigged. Some of
the large ore was crushed ; the coarse part was jigged, and the
fine cleaned in buddies.
Hioa.t — The rough blocks obtained from the mine are cleaved
by means of steel wedges into sheets J inch or less in thickness,
and these are cut by the " scriber" into the shapes required for
stove windows. There are a very large number of patterns,
ranging in size from i x i to S x 10 inches. The cutting is done
des mloermii dans ta Saxe, le Haiti et la Prosse Bbdnaus,'' JnnolM dti
Minei, air. S, voL xz., 1S91. p. 5.
Monroe, "Ths New DresBlng Works of St. Joseph Lead Compauj', at
Bonne Terre, Miasoari," TVaat. Amer. Imt. M.E., toI. iril., 18SE, p. 659.
* Sopwitb, " The DiMilng of Lead Ores," Proe. Int. C. E., vol. xix.,
i86^a p- 106.
t VtT Bergbau unJ HUtteTihetrith dtt Sttchemiclitr Bergieerkt-Aeiitit-
I'ereiiu, Cologne, 1S86, p. 10, and Tables II. and IlL ; and£. a. h. Z.,
1SS6, p. 476.
i FbUllpa, " Mica Mining In North Carolina," Eng. Mia. Jour., to), zlvl.,
1SS8, p. 4iS.
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6i6 ORE AND STONE-MINING.
witii a knife along the edges of a template made of iron or tin-
plate. The blocks of crude mica yield from -^jy to J of cut mica
fit for the market. The refuse Bcrapa are now ground ap into
fine powder and used in the maoufacture of wall-paper, tinsel,
hiiir-powder, and lubricants.*
Kitrate of Soda. — Tbo process of extracting the commercial
nitrate from the crude caliche has already been suffidentlj
described, in speaking of the preparation of minerals by solution
and crystallisation.
Oohre. — Native ochre is ground under an edge-runner with
water, and the product is run into settling pits. Coarse sand
settles first, and further away the sediment consists of fine ochre,
which is dug out and dried. The ochre deposited by the water
coming from cementation pits has simply to be dug up and dried.
The native umber of Devonshire ia stamped and ground under
edge-runners ; the umber suspended in water ia pumped up and
allowed to settle in tanks until it can be dug out. It is then
dried in the tnme way as china clay.f
Oiokerlte. — Some of the mineral is brought up in the form
of fairly clean lumps which have been picked out underground
and put into sacks. These, together with similar pieces picked
oat above ground and scraped free from dirt, are malted in large
semi-spherical open cast~iron pans and boiled. When allowed to
settle, the earthy matter falls to the bottom and clean ozokerite
floats on the top. This is ladled out into cylindrical moulds, and
on cooling furnishes the large loaves of commercial ozokerite.
Water is added to the earthy residues at the bottom of the pans,
and the whole brought to the boiling-point. Ozokerite rises to
the top and is skimmed off, whilst the residues remaining at the
bottom, which still contain some lo per cent, of wax, are sold to
dealers who extract it by means of benzine.
The small stuff coming from the mine which will go through
a grating with bars 2 inches apart is put into a tub of water ; tiie
wax rises, is skimmed off with a sieve and purified by melting,
and the earthy residues are sold, or are stocked untQ the miner
puts up plant for extraction by benzine.
Phosphate of Iiime. — The varieties of this mineral are so
numerous, from the hard compact apatite of Canada to the pulveru-
lent mineral of the Somme district, that the modes of treatment
must necessarily be extremely different ; sometimes also the miDeral
is sold finely ground and put up in sacks ready for the farmer, in
otiier cases the miner sa^sGes himpeH with removing all waste,
and leaves to other paeons such processes as milling or manu-
facture into superphosphate.
• Nitie, " Ground Mica Industry in North Carolina," £1117. ilin. Jottr.,
vol. liv., 1891, p. 393.
t Frecheville, "Ihs Umbei Deposits at Aahburton," TVaiu. S. Geol.
Soe., Comtcall," toI. ii. p. 319.
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DRB8SIKG. 627
As a rule, the treatment may be summed up as drying and
grinding, often preoeded by a prejiminory washing. For instance,
the phosphate of the Somme is dried first upon iron-plated floors,
and then in a Ruelle stove or a revolving cakiner. This prepares
it for grinding. The first grinding is done between two vertical
stones, and all that is fine enough is drawn out by an exhaust
fan ; the portion which is too coarse to be sucked up by the
current of air passes into a mill with horizontal stones and is re-
ground. After being put into sacks it is ready for the manure
merchant, or for the farmer if he applies it to his land direct.
The nodules of the South Carolina phosphate are freed from
the sand and clay by a mechanical washer, in the form of a heliz
revolving in a trough. The material is fed in at the lower end
and is gradually screwed up to the other against a strong stream
of water. The water carries away the waste, and clean lumps are
delivered at the other end. The washed nodules aro dried in.
kdlns and are then ready for export.*
Fotasflluin Salts. — The two principal potassium salts obtained
by mining are carnallite and kainite. Simple grinding is often th»
only preparation before sale, but in some cases, as explained on
page 608, the carnallite undergoes a complicated treatment by
solution and crystalliaation, for the purpose of extracting chloride
of potassium and utilising the by-products obtained in these
processes.
QniokBilver. — The great intrinsic value of quicksilver ore
enables hand-picbing to be carried further than would be
compatible with a mineral of little worth. At Idriaf the loss of
mercury was so great under the old system of wet dressing,
in spite of the nigh specific gravity of cinnabar, that this
method was given up some fifty years ago. Nowadays, the
preparation for the smelting la done solely by crushing, sizing, and
hand-picking. The stuff broken in the mine is separated under-
ground into waste, poor ore and rich ore. The first is left in the
workings, and the two kinds of ore are tipped separately on to a
grating with holes of 4 inches (too mm.) across. The coarse
lumps are crushed by Blake's atonebre&kers, and the broken ore
which is too big to pass through holes of J- inch (lo mm.) is
hand-picked ; the portions so separated are made ready for the
smelting works by further crushing. When poor ore is being
treated, waste can be picked out and thrown away at once. The
stuff passing through the 30 mm. mesh ia crushed by rolls and
sent to the smelting works.
The " smalls " which passed the 100 mm. grating are screened
on a 2-iDch (50 mm.) sieve ; the coarse goee to the stonebreaker
and the fine to screens of different sizes. All that is over ^ inch
* Benedict, ' ' UuimK, Washing, and Calcining South Carolina Phosphate,"
Eng. Min. Jtiur., vol. Uil,, 1S92, p. 349.
T Da*k. k. Queektilbtrtrerk za Idria in Krain, Vienna, 1S81, p. 19.
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628 ORE AND STONE-MINING.
(20 mm.) is picked, and some waate taken out ; what is under
this size is passed through the rolls and so made fit for the
furnaces.
Salt. — The mode of making a saleable product from brine has
already been described ; but it must not be forgotten that brine
itself is sold as such to works which make alkali by tb« S<Jvay
procees.
Some rock-salt la prepared for the market by crushing. At
one of the Cheshire mines there are three pairs of crushing rolls
one above the other, the first pair coarsely fluted, the second pair
fluted, but less coarsely, and the third or lowest pair smooth. The
rolls are from 18 inches to 2 feet in. diameter and 2} feet long.
The rolls of another crusher are made up of toothed rings
threaded upon shafts, and ao arranged that the teeth of one roll
fit between two of the rings of the opposite roll. Some of tbe salt
is also ground by a disintegrator.
Silver. — The ores of ^ver may be divided into two classes :
silver ores proper and argentiferous lead and copper ores.
Many of the silver minerals are very friable, and are liable to be
carried off with the refuse, if subjected to the ordinary wet dress-
ing processes ; the preparation of such ores at the mine is gene-
rally limited to crushing, picking, and cobbing. The miner then
relegates to others the ta^ of extracting the precious metal by
methods based upon its affinity for quicksilver or molten lead, or
upon the lescbing properties of hyposulphite of soda.
Argentiferous lead and copper ores are concentrated by the
processes in vogue for the baser metals ; but if the proportion of
silver is large, a greater amount of labour may be expended upon
hand-picking and cobbing than would be permissible with ores of
lead and copper alone.
Slate. — Two articles of commerce are made at the quarries :
roofing elates and thick slabs used for cisterns, billiard -tables,
and tombstones. The slate arrives at the surface in the form
of large blocks, often weighing two tons or more. These are
divided by splitting into slabs about 3 inches thick, which go to the
sawing tables. The circular saws cut up the slabs into pieces
suitable for the operation of fine splitting ; by the careful and
dexterous use of his wedge and mallet, the quarryman is able to
split the slab into thin sheets, which at Festiniog often do not
exceed | inch in thickness. These have to be trimmed, generally
into a rectangular form. Though this operation can be and
often is performed by hand, it is more common to use some
Idnd of knife worked by machinery (Fig. 639). The slates are
then sorted by hand according to their quality. The slabs are
first split out of blocks, and are finished by being sawn into shape
and planed smooth by machinery.
Stone.— 'It is impossible in a general treatise to enter into any
details concerning the preparation of stone at mines and open-
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DEESSING. 629
works. Some stone is Eh&ped by hammering, into paving blockB
or " setts "; much is crushed by stone breakens and sold ae road-
metal after removal of tho fine by screening ; freestone is sawn so
aa to suit the builder; Sags are obtained by splitting micaceous
sandstone along the planes of bedding and trimming the edges,
and, lastly, gunflinte are made from the well-knoirn nodules by
the dezteroos chipping of the *' knapper."
Sulphur. — This element is obtained from the rock, which
contains it in the native ^late, by simple liquation in a kiln of
some kind, intermittent (ealcaron«) (Fig. 67 7) of cootinuous (Gill's
furnace), by liquation in steam-heated cylinders, or by dbtiUatioa
in iron retorts ; this last process, which was at one time practised
with rich ore in the Aomagna, is now almost entirely abandoned.
Tin.* — The tin ore obtained from veins usually contains
the cassiterite so finely disseminated through the stone, that a
considerable amount of comminution is required before the valu-
able grains ore thoroughly liberated, and so rendered capable of
being separated by washing. In Cornwall the first process is a
preliminary cruslung by a Blake's stonebreaker, followed by
stamping until the pulp will pass through a fine grate. The pulp
is led into round buddies in order to produce a first cont»ntrate,
contfuning not only all the cassiterite, but also the iron pyrites,
mispickel and other metallic sulphides with which it is so often
assoinated. By repeating the operation of huddling, a concentrate
is obtained, which is subjected to " tossing and packing " in order
finally to prepare it for the furnace. This first concentrate, known
in Comwiill by the name of xohite, is dried upon the top of the
calciner and then roasted in the manner already described. After
roasting, the huddling is Tepeat«d, and, lastly, the tossing and
packing, with the result that clean tin ore with 65 to 70 per cent,
of metal can be put away in bins, ready to be done up in sncks
and despatched to the smelting works. In some cases the ore is
not contaminated with sulphides, and no roasting is required.
The tin-bearing sand and gravel, which have furnished and are
BtUl furnishing such a large proportion of the world's supply of the
metal, can be treated in a speedier fashion. The wash-dirt is
simply shovelled or hoed against a stream of water in a ditch or
trough ; the light waste is washed away, and the heavy pebbles
and clean grains of cassiterite are left at the head. This is the
method usually employed in the East.
The tin-gravel worked at Bestronguet Creek,t near Triiro, was
washed with water in order to separate adherent clay, and then
* Feiffnson, " On the Mecbanical Appttancei nBeii for drearioK Tin and
Copper Ores in Comwall," Proe. Iiut. itech. Eng., 1873, p. 119 ; Hendenon,
"On the Methods KenarallT adopted in Cornwall In dreBBing Tin and
Copper Ore*," Proe. Intt. C.E., vol. xrii., 1857-58, p. 106.
t T«7lOT, " DcHiiption ol the Tin Stream Worki Id Reationgnet Creeit,
near Trnro,'' Proe. Intt. Mtth. Eng., 1873, p. 161.
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630 ORE AND STONE-MINING.
passed to a revolving sieve. The fine stuff was jigged, and finally
cleaned by a propeller-knife buddle; the large pebbles were
picked over, and thoee containing tin were stamped and treated
like vein rock.
At Mount Bischoff,* tn Tasmania, the process of dressing may
be briefly summed ap as follows : Comminution by stamps, and
extraction of the tin ore from the pulp by jigs and revolving
tables.
Zino. — Calamine has sometimes to be washed, in order to rid
it of clay, before it is crushed and jigged like lead ore.
Blende is dressed in the same way as lead ore, and is often ob-
tained from one compartment or portion of a dressing macliiiiei,
whilst galena is being discharged from another.
LOSS IK DBESSIirO.
The loss in dressing is frequently very great, and proofs of this
fact constantly come under one's notice. Old heaps of mining refuse
left by former workers may be seen yielding an abundant harvest
to a later generation, and even with the machinery of to-day the
extraction is far from perfect. For instance, in the j-ear 1891 no
less than 879 tons of dressed tin ore, worth ;£33,704, were ex-
tracted from the muddy water discharged into the " Bed River "
and its tributaries by some of the large tin mines near Camborne
and Redruth.
The loss is due to several causes. First comes imperfect
severance of the valuable mineral from the worthless constituents
of the ore dnring the crushing process ; this is unavoidable if the
mineral occurs in the state of very minute particles. Secondly,
the thickness of the dirty water escaping from the machines,
which impedes the subsidence of the £ne grains ; thirdly, want of
care on the part of the persons placed in charge of the machinery.
In addition to these causes, which are general, special reasons ac-
counting for loss will be found with certain minerals : the
amalgamation of gold is prevented by grease, by any coating or
film upon it which impedes close contact with the mercuiy, by the
presence in the ore of substances which have an injurious effect
upon the mercury, " sickening " it, or in other words depriving it
of its natural activity. Again, if the mineral is flaky, it will not
fall GO easily in water as if the particles more nearly approached
a. spherical shape.
The actual loss has been very carefully ascertained in some
cases, though less attention is paid to exact determinations than
the subject deservcis. M, Bellomf cites three cases of loss at mines
producing argentiferous galena and blende.
The ore delivered to the Himmelfahrl Works, near Freiberg,
■ Ea;ser, " AdvaDtagea ol Ore-dressiDg bj Antomatic Hacliinery,"
Trint. Jftn. Attoe. and hut. Conmall, vol. ii., t8£8, p. 51.
■\ Op. cil., p. 624.
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DRESaiNQ. 631
containe sj per cent, of leaA, 0-275 P^'' '^"^^ °^ ^i^i^i, aQd 7'5 oze.
of Bilver per metric ton (33 grammee per 100 kil.), besides a
little copper, i per cent, of arseoic, and 5 per cent, of sulphur.
Tlje galena is dressed to 85 per cent, of lead and 96 ozs. of silver
(300 grammes per 100 kil.), the blende to 40 per cent, of zinc and
9'6 OKS. of silver {^o grammee per 100 kil.), the pyritic minerals
to 40 per cent, of sulphur and i5 oze. of silver (50 grammes
of silver pea- 100 kiL). The losses are found to be zi per cent, of
the Bilver, 38 per cent, of the lead, and 60 per cent, of the
sulphur.
At the Churprini "Works, also near Freiberg, the raw ore con-
tains 3 per cent, of lead, and 3 ozs. of silver per metric ton (gi
grammes per 100 kil.), and a dressed product is prepared with
70 per cent, of lead and 16 ozs. of silver per ton (50 grammes
of silver per 100 kit.). The loes in dreseiog is 23-8 per cent, of
the stiver and 14-9 per cent, of the lead.
The ore treated at Ems contains 4 per cent, of lead, 2^ per cent,
of zinc, and 1-7 ozs. of silver per metric ton (54 grammes per 100
kit.), but the enrichment by washing is not carried so far as at the
other works. The galena is dressed to 36 per cent, of lead and
g6 oze. of silver per metric ton (30 grammes per 100 kU.), and
the blende, which is not argentiferous, to 44^ per cent, of zinc The
losses are 8 per cent, of the ailver, 6 per cent, of the lead, and 34
per cent, of the zinc.
It is to be regretted ttiat so many dressing establishments in
this country are working entirely in the dark, and are, therefore,
utterly ignorant of the losses that are going on.
At few places in the world is the loss more carefully studied
than at the mines of the Fest&rena Company in Northern Italy,
for a sample is taken from every waggon of crushed ore before it
goes to the milts. The quantity of gold in the ore treated can,
therefore, be ascertained with great accuracy, and by comparing
this amount with the quantity extracted, it is found that about
one-fifth escapes amalgamation and is lost ; the ores sometimes
contain 10 to 30 per cent, of pyrites.
Another kind of loss which requires to be ascertained is the
purely mechanical waste in preparing stone for the market. In
the case of slate it is very large, for the blocks brought from
the workings into the mills frequently yield only 35 per cent, of
roofing material. As the amount of rubbish produced in getting
out the blocks is also considerable, the quantity of saleable slate is
<^ten only one-twelfth of the actual rock excavated.
Seeing that the propoi-tion of waste material, whether in ore
minea or stone mines, is usually targe, it behoves the miner in
laying out his dressing establislunent, to make provision for the
disposal of great quantities of refuse.
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ORE AND STONE-MINING.
SAUFIiINQ.
The miner may have to sampie the produce of his mine for a
variety of reafioiu. Sometimes sampling is necessary in order to
ascertain the amount of money due to the workmen ; it is indis-
pensable when the loss in dressing has to be ascertained, and,
lastly, the miner, uSt&r preparing his various products for sale,
requires samples for possible purchasers.
Sampling may be done by faknd or by machinery. Four methods
of hand-sampling may be mentioned :
HAKD-SAMFIjIKO. — I. Sampling by taking out small
lots. — If thti mineral is in coarse lumps and the valuable ingredient
irreguiarlj distributed, picking up a few stones here and there
is not likely to yield a very correct sample ; but, on the other
hand, if the mineral is already crushed, and if the small tot
is taken regularly, say for instance every tenth shovelful, it is
possible to obtain great accuracy. Thus at the Pestarena mines
the gold ore before being milled is crushed by rolls until it will
pass a sieve with three holes to the inch ; and from each waggon
of crushed ore about 2 kilos, are taken by a tin measure. The
load is spread out horizontally with the hand and a tin measure
is filled from this flat surface and thrown into a tub. Each
waggon is weighed, and the 2 kil. represent about ^^th of the
load. At the end of the day the tubful is taken as the sample of
the stuff sent to the mills. From this large sample a small one
is prepared by the process of quartering, which will be deaoribed
immediately.
This me^od of sampling will also suffice in the case of an ore
of small intrinsic value, such as an iron ore, consisting in the
main of one mineral.
2. Trenohing.— In order that this method of samphng may
be accurate, it is necessary that the mineral be well mixed, and
where a valuable ore is concerned, great care is expended upon
the operation. It may happen that there are a number of small
heaps of dressed ore, each produced by a different gang of men,
which have to be mixed before being sold in one lot. The stuff
from the first heap is spread out evenly on a smooth flat floor.
Layer after layer is added from the other small heaps until
a large square or rectangular pile is obtained made up of
horizontal strata. The mixing is now carried out by taking
off a slice from the side of the heap with a shovel, so as to
cut through all the layers ; the stuff is toesed on to the floor
and spread over a large area, and the thorough intermingling
is aided by a boy who stirs it as it falls. The original heap ia
cut avay slice after shce, and gradually, at the side of it, another
heap is formed with the particles thoroughly mixed, which is ready
for the operation of trenching; it maybe, for instance, 10 ft. wide
by 15 ft. long, and 18 inches high. If the operation of turning
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DRESSING. 633
over and mizmg was carried on along the long side of the rectangle,
a couple of tranches are dug acroes the heap at right angles to
this direction, or in other words parallel to the short sides. The
ti-enches are cut down to the bottom, and after they have been
carefully swept out, the sampler slices off small portions of the
sides with his shovel. All that be cuts down in this way is
shovelled into haad-barrows, and oonstitutea the large sample,
which has simply to be reduced in bulk by quartering.
With coarsely broken mineral the part shovelled out in making
the trench is often takeu as a first sample and not the thin slice^i
from the sides, as is done with fine material.
The two trenches are sometimes cut at right angles to one
another, f coming an ordinary cross, or along the diagonals, forming
"■;. Andrew's cross, and the heaps are often round instead of
)eing rectangular.
^„, Quartering. — Quartering is a process of dividing a given
lot of mineral again and again until a sufficiently small sample
remains. The mineral is made into a conical heap by letting each
Fia. 696.
Fia
«95.
f^
^
^
y
shovelful which is emptied fall down evenly over the apex of the
cone. The apex is pressed down, and the heap is spr^d out till
it forms a low truncated cone, a cross ia marked upon it with
the point of the shovel, and the two opposite quarters, say
I and 3 (Fig. 695), era scraped aside and discarded, leaving
3 and 4, or one-half of the original sample. These two
quarters, 2 and 4, are mixed by hand, a new conical heap
made and the quartering repeated. The next time the sampler
will retain the quarters i and 3, and put aside 2 and 4. If the
mineral is not fine, it should be crushed once or twice and put
through a finer sieve during the process. In this mannera large
sample is reduced sufficiently in bulk, to give the miner a small
lot which is a fair average of the whole.
(4) Sampling Shovel.* — This implement is dedgned for
the purpose of obtaining an average eample of a heap of
mineral bv merely shovelling it over. It consistB of a flat
reotangolf^ plate with vertical sides (Fig. 696), and two vertical
partitions which enclose a central compartment occupying one
fourth of its area. This compartment is closed at the back or
handle end, whilst the rest of the plate is open. After the
• Eng. Min. Jour., vol. li., 1891, p. 718.
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634 ORE AND STONE-MINING.
shovel has been filled by & thrust into the heap of finely crushed
mineral, it is easy to discharge the outer three-fourths of its coa-
tents over the back end, and then, turning it over, to deport
the centml quarter in a separate place as the sample.
MACHIITB SAUPIiIKO.— While we have generaUy been
content on this side of the Atlantic to go on with the old-
fashioned methods of band-sampling, much ingenuity has been
displayed in the United States with the object of producing
machinery for doing the work, and thereby saving time and
labour, to say nothing of furnishing more accurate results.
According to the principle upon which they work, sampling
machines may at once be divided into two great classes : •
(0 Machines which take part of the stream oF material for the whole
of the time,
(z) MaohineB which take the whole of the stcfam of material for part
of the time.
(i) In the former class a spout or opening of some kind is
arranged so as to divert part of the stream of ore, coming From a
crusher for instance, into a separate receptacle.
Two samplers used some years ago in Colomtlo belong to the
first class. One of them is a hollow cone with four large holes ;
the stream of crushed ore falls upon the spex, and the particles
spreading themselves out slide down over the steep surface. The
path of some of the particles leads them to the holes, where they
drop through, forming a sample of the whole. The size of the
holes can be arranged so as to extract a given percentage of the
total quantity, and this first sample can be reduced in bulk by a
second passage over the cone.
In the other the desired result is obtained by letting the ore
fall on to three inclined shelves one above the other, f £ach shelf
has openings which allow a portion of the cffe to drop through.
The ore dropping through the fii«t sbelf falb npon the second,
which in its turn eliminates part and lets the remainder drop on
to the third shelf, where the process is repeated. The portion
which has passed through the three shelves constitutes the
sample.
Glarkson's Rapid Sampler, an English machine (Fig. 697),
consists of a revolving conical hopper, supplied with the mineral,
which runs through a hole in the bottom, and drops on to the
apex of a cone. In the path of the falling stream of minend,
now converted into a hollow rotating cylinder, there are two
segmental spouts, which intercept any desired proportion of it,
and BO furnish two independent samples. The size of the spout
determines the percentage which is diverted as a sample.
* BridgmaD, "Anew System of Ore-sampling," IVani. Ainer, Init.M^.,
vol. iXn iS9i,p. 416.
t EglestOB, " Sampling Ores In Colorado," Engiattring, vol. xxiL, 1876,
P- 49S-
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DRESSING. 635
(z) In the second class the whole Btre&m ie deflected at regular
intervals, and this method has the advantage of ensuring the
proper proportion between the fine and the coarse, which cannot
always be attained by the fixed spout ; where the constituent
minerals vary in friability the accuracy of the result must de-
pend upon this proportion being strictly maintained. In
Brunton's • sampler the stream of ore falling down a vertical
trough is diverted to one side or the other by a partition which
is moved backwards and forwards by very simple machinery.
There are means of regulating the proportion of the time during
which the stream is being turned into the side for receiving the
sample.
Bridgman's ore-sampler t has the advantage of supplying two
FIO. 697.
absolutely independent samples, and it divides them as often as
denirable previous to a recrushing.
The work is begun by a horizontal revolving wheel formed of
two concentric rings, with vertical partitions dividing it into
eight segments (Fig. 698). Underneath this first " apportioner,"
as it is called by the inventor, comes a second one (Fig. 699) ; it is
a funnel with openings, a, b, 0, d, on the side, and is made to
revolve in the opposite direction to the first. It is succeeded by
a third of similar construction. The ore is fed from a pipe on to
flome point of the first apportioner, and each segment necessarily
receives one-eighth of the stream; segment No. i has a spout
which travels round the outer circumference of the apportioner
below it, passing over the holes a and b, whilst the spout of No.
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636 ORE AND STONE-MINING.
5 takes an inuer path, including the holes c and d ; the spout»
of 2, 3, 4, 6, 7, and 8, deliver their ore into the centre C. One-
eighth of the fitream from the Bpout of No. i drops through a and
another eighth through b ; the rest falls on to the paits A and
B of the funnel and is discharged iDto the centre. likewise
the original one-eighth from spout 5 drops in part through
e and d, and in part on to A and B. The portion passing
down through a and h, or through c and d, is therefore one-
quarter of one-eighth, or one-thirty-aecond, of the original bulk.
The third apportioner again oollects one-quarter and discards
three-quarters of each of the two samples coming to it, so that the
final samples furnished b; the machine are both ^^ of the total.
These first samples are then recrushed and passed through
another machine of similar construction hut giving only one
sample.
Mr. Bridgman has likewise devised a small sampler for use in
the laboratory.
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( 637 )
CHAPTER XIV.
PRINCIPLES OF EHPLOTMENT OF HIKIXO LABOUR
Uodea of pa^moat, aooording to time, measnre ot weight ; tribvte
Pbbsohs employed at minee ma; have their witges reckoned in one
of four different ways ;
1. Bj time.
2. ,, measure or weight.
3. „ a oombiDBtloQ of Noe. i and z s;st«mi.
4. :, valne of the mineial obtained.
(i) The first sjBt«m is lai^ly adopted for surface labour,
such as is required on the dressing floors. Enginemen, stokeis,
millmen, smiths and carpenters are likewise paid so much a
day of a stated number of hours. A time-book ie kept, and
the wages are reckoned up at the end of the week, fortnight,
or month by a simple multipli cation sum. For true mining
or quarrying— that is to say, for excavating valuable mineral
and removing worthless rock — this system is far less common
than the other three. There are objections to it both on
the part of mino-owners and on the part of many of the men.
The owner has to employ more foremen to look after the work,
and an amount of auperviaion which would be sufficient at the
surface is utterly inadequate below ground, because the working
places are not within sight from any one point, and can only be
reached by traversing low and tortuous passages, or by climbing
down and up laddero. The men, too, in many cases prefer to be
paid on some system, which gives the skilled and steady miner
the advantage of deriving some profit from Mb exertions, over and
above the average daily wage he would receive if time were the
only standard for good and had workers alike.
In rare casee persons are hired for the day only ; this is dona
sometimes at the ozokerite mines at Boryslaw, where the agent
picks out in the morning as many men as he wants from t^ose
assembled at the top of the pit.
In new countries or distncts, payment of miners by the day
may be necessary at first, because the work is so strange that
the men are afraid to enter into contracts, which would appear
perfectly reasonable and satisfactory to them if they had been
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638
ORE AND STONE-MINING.
used from boyhood to this system of arrangiog eanuDgs.
After the more enterprisiiig men have leamt by actu&l pntctioe
what they are capable of doing, they drop into the contract
system, and in due course of time the others follow thenL.
(2) Much of the work at mines is r^ulated by a system of
piecework of soine kind, calculated by measure or by weight.
In Cornwall and Borae other districts, work done ia this fashion
isknownas "tutwork." No doubt the original meaning of the
word was " dead work," from the Qerman word " todt," because
preliminATj and unremunerative work was paid for in this manner ;:
nowadays the meaning of the term is extended, and it includes
the excavation of ore. In driving a level, for instance, the man-
ager specifies that the height shall be 7 feet and the width 5 feet,
and agrees to pay so many pounds for every yard or fathom of
advance. As a. rule the mine-owner provides all the necessary
materials, and deducts their value at the end of the contract.
An example or two will make the system plain.
THB ADVEKTtJRE MINING COMPANY, LIMITED.
Tutwork pay for tha Month of May iS36.
John Smith and Pabtnkbs. 6 Men.
Amount.
SinkJng
Patting in '9 stalls '.
DBDDCTlOIiS.
Cash on aoconnt
CandlM, 7a lbs. at 4rf.
Powder, 100 IbB. at 4^- .
DyuBmite, 20 lbs. at U. 8d. .
Fn«, 34 coilB, at 5d. . . .
hx.
FL
In.
Pifot
£
4
40
27
-1
6
.0
d.
S
8
4
»
°
140/.
■ ■
J
13
18
4
4
~
Smith's cost ....
Powder cans, at i». .
Doctor and olnb
Balance
.o|
■ '1
'3
13
.o|
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PRINCIPLES OF EMPLOYMENT. 639
The meaDing of this pay-bill ia that John Smith and five other
men took a contract to sink a certain shaft at J£^ per fathom,
and to stope part of the lode at ^^3 per fathom. They sank the
shaft 4 fathoms 2 feet, and stoped away 3 fathoms ; in addition
to this they put in some timber, a matter not included in the
original contract, aod for which they are credited with j£^ los.
extra. The gross balance due to them is therefore £_^a i6s. Zd.,
agaiuEt which they are debited with the cost of the candlee and
explosives sapptied to them, and with their Bubscriptions for
medical attendance and accident club. While the contract
was running they received ;£2 1 on account, so that on the pay-
day they took up a balance of ^13 i3«. lod. In a contract
of this kind the leading man, John Smith, ia known as the
" taker."
In Gtoping a vein, the price is calculated per square fathom of
advance for its whole width; thus if a lode is 4 feet wide, stoping
I fathom of ground means the removal of a block 6 ft. high
6 ft. long and 4 feet wide ; in other words, i44cubicfeet. In wide
lodes the men are sometimes paid per cubic fathom excavated. At
one British lead mine, where the lode sometimes measures several
fathoms from wall to wall, a standard price is arranged for a
width of 6 feet, and where the stopes are wider than this the
men are paid extra. In order to prevent loss of ore through
carelessness, the men are paid a premium of 15s. a ton for all the
lead ore they save.
Another example (p. 64o)givesan instance of " tutwork" wages
calculated by weight. It is copied from the figures on the back of
the little envelope in which the money ishanded to the "taker" on
the pay-day. The account shows that Richard Williams and his
six partners excavated 120 tons 9 cwt. of tin ore ("tlnstuS'")
at 6». per ton, and were credited with ^36 2». 8d. Against this
they had to pay^^^S 4». 4d. for materiaJs (candles, explosives, &c.),
7». for doctor, s»- 3d. for club and is. gd. for barber," leaving a
balance of ;^3o 4^. ^d. to be divided among them, that is to say
£,t IS. 7c{. per man per week.
A thiril basis of payment b the number of inches bcH«d in the
shift. This plan was in vogue in stoping the wide lead-lodes in the
Tipper Uartz some years ago ; it necessitated careful supervision,
for otherwise the men bored their holes in the softest places thc^
could find, or in positions enabling them to wield their hammers
with the greatest ease, without any thought for the work required
from the shots. A foreman came round at the beginning of the
shift, and pointed out how the holes were to be placed ; in the
middle of the shift he returned, measured the depths bored, and
then charged and fired the holes while the men rested. The
positions for fresh holes were then indicated, and at the end of
* The item " barber," a charge of 31^ per man per moDth, still remains
in a few of the oldest minei In Cornwall The barber attends at the
mioaa on Batordars.
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640
OBE AKD STONE-MINING.
the shift the depths were measured and booked, previous to the
charging and blasting. The price paid was i M. 38 Pf. per
metre of hole bored upwards, and i M. 13 K. per metre of hole
bored downwards ; in the latter case the men oould put water id
the holes, which keeps the finely powdered rock ua suspension and
allows the cutting edge of the tool to do better execution.
The men working away the great pyritea deposit at Rammels-
bei^ in the Iiower Hartx by means of boring machinery are paid
WHEAL CHANCE.
BICHASD WILLIAUB AKD FASTMEBS.
Fay for 4 weeks ending Z7th lt%j.
Paid lothJuDe 1S93.
'""■■■ i'-
Ft.
^
Ptic*.
61-
5
2
18
J.
Driving . . -1
SS' ; : :!
8
4
1
CwU.
Stoping . . .120
Stems
9
SnbsUt ....
Materiab ....
Doctor, Club, and Barber .
Balance
£
S
14
4
• ^
30
4
4
per metre of hole bored, as this method is more convenient than
measuring up the amount of "ground" removed in wide nork-
ings and paying per cubic metre. The latter system, however, is
adapted in driving levels and sinking shafts where the dimensions
of tJie excavation are r^^ular.
In removing overburden, where everything has to be sent away
indiscriminately, payment per cubic yard excavated is common,
just as it is in making railway cuttings; this system is adopted
with the men who uncover the iron ore in Northamptonshire
(Fig. 324), whilst those employed in getting the ore are paid so
much per ton put into the waggons.
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PEINOIPLBS OF EMPLOYMEHT. 641
(5) The oombinatiou of the two methods, payment hy time
and payment by measure or weight of some kind, may be adopted
when men are too inezp^enced or too Umid to take contracte
depending solely upon results. This plan has been found to
answer at a pyrites mine in North WaJes, where the minentl is
got by the aid of rock drills worked by compressed air. The
miners receive a fixed wage of a pound per week and a premium
of a penny per foot for every foot bored over 12 feet per day of
eight hours. The company finds the machines and all tools
The mine is worked in three shifts of eight hours each ; in two of
them the men are merely boring, and in the third shift a set of
blasters come round to charge and fire the holee. Of course, as in
the Hartz, the position of the holes is planned by the foreman.
By working in this way the men generally make from 31. to 4«. a
week extra pay, for they are able to bore 40 or 50 feet a week
more than tiie standard task. The ore is fairly uniform in hard-
ness, for otherwise it would be impossible to maintain a single
taxis' for the whole of the mine. This system has been advan-
tageous both to the men and to the company. I^vious to its-
introduction the men were all on one dead level, and had do
interest in exerting themselves ; they each got their ^^i a week
by doing the minimum amount whidi enabled them to escape a
scolding from the foreman, whilst now the man who works hard
feels that he will get s<mie recompense for his extra exertions.
The company benefits by having an increased output at a smaller
cost per ton, without any extra plant.
(4) We now come to the fourth or last system— viz., payment
by value of the product. This system has had its home in the
south-west of England for many years, and has been transplanted
by the uHquitous Comishman to many other ore-mining districts.
In Comwatl it is known as working on " tribute."
Under the tribute system a gang of men agree to hand over
to the mining company all the ore they raise, on condition that
they receive a certain proportion of its value. Thus, supposing
that the tribute is ^, or 59. in the;^i, and that a couple of men
produce marketable copper ore worth ^^50, their share wiU be
;£$o -^ ^ or;^j3 io«., lees the cost of the materials they have
been supphed with, and all the expenses for winding, dressing,
sampling, &c. In other words, the tributer may be said to take a
Eublease of part of the mine and pay a royalty, in this case of ^
or 75 per cent, for the permission to work accorded to him. But
it must be recollected that the mining company renders the place
accessible to him, keeps it drained and ventilated, and supplies
him with machinery for raising his ore to the surface and dressing
it, which he could not provide. The tributer is therefore a
person who can speculate upon the value of the ore in a certain
small working area, without having any capital b^ond his brain
and ^i" muscle.
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643
ORB iND STONE-MINING.
The precise nature of this mode of pajmeDt will be beet nnder-
Btood by an actual example.
Joha JoDM and Partners,
WHEAL CHANCB.
Pay for 4. wseki andmg 37th Hay.
P^d loth J1U14 1893.
Tbubm
Tribita.
.-.t
T. C. Q.
Tin 1:6:3:
Price £$2 pet ton
Valne ;£70 »■ 8''-
Eotnming charges
Sabsiit and dreMing . .
HaterialB and draw&lg .
Doctor, clnb, and barber
Balance
Lii.
23
.3/4
46
14
'■ 1
i
1
5
£
3
•3
4
9
»5
,
4
4
■ £
"
'
' I
The pay-ticket shows that John Jonee and \a& partners, a
gang of three men, raised a certain quantity of crude tin ore
(((TMttijf) vhich, according to assays, contained I ton 6 cwt.
3 qrs. 23 lbs. of clean tin ore iftlack ii-n). The value of this
quantity, at £,it per ton, is ^70 i«. %i. The pay-ticket also
states that the tribute was I3«. ^d. in the pound, or, in other
words, two-thirds of the value. The gross total credited to
the gang was therefore £,4(1 14s. <,d. Against this come the
returning changes, sulsist, dressing, drawing, and sampling, as
follows : —
{. B. d.
Retamlng ohatgw
SabslBt . . .
Dresdne
Hateriala
Drawing and samplins
Doctor, 5>., Clab, 4«. (id~, Barber, ti. 6d.
These deductions requiiv a word of explanation. The retom-
ing charges represent the cost of treating the "stuff" from the
time it goes to the stamps until the dre^ed tin .ore (&2aefe tm)
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PRINCIPLES OF EMPLOYMENT, 643
t for the smelter. The amount charged varies slightly in
rent minee.* " Subsist" is another name for an advance, or
money paid on account, during the running of the contiaot, which
in this case lasted eight weeks. The term " dressing " as used in
these accounts is not verj happily chosen, because the retnming
charges represent all ^e cost of stamping and washing. The
" dressing " referred to in the pay-bill is the preparation of the
"tinstuff" for the stamps by "ragging," "spKlling," &c. The
charge varies from ^d. to 6d. per ton, according to the hardness
of the veinstuff. In this case the books of the company showed
that 96 tons 6 cwt I qr. of tinstuS* had been dressed. The
" materials " included candies, powder, fuse, dynamite, pick hilts,
detonators, a shovel, ctay for the candles, and the smith's cost
for sharpening drills and picks.
"Drawing" is the Cornish term for winding, and is charged
at the rate of 3(2. per ton. The "sampling" refers to the assays of
the tin ore made upon the vanning shovel by the .mine agent ;
they are charged at the rate of le. each, and it is upon the
results of these assays that the mine-owner ascertained that the
96 tons 6 cwt. I qr. of " tinstuff" contained i ton 6 cwt. 3 qr. 23 lb.
of " black tin." One of the three men being a bachelor, paid only
6d. per month for the doctor, instead of the usual i«. of the
married man, whose wife and family ore likewise entitled to
receive medical attendance.
In former days the " tribute," or proportion of the value re-
tained by the workmen, was jiublicly fixed by Dutch auction on
the "setting" day. The miners assembled outside the mine
office (eounting-hmue), and the manager, after reading out the
nature of the "pitch," or working place, asked for bids; the
lowest bidder received the contract. If a certain place seemed
likely to be profitable, there was frequently much competition
among the men in order to get the "pitch." Nowadays the
agreements are often made privately. It is evident that the
richer the lode, the smaller will be the proportion of the value
necessary for giving the men a fair return for their labour ; in
other words, the tribute will decrease as the lode improves.
This system of working has many advantages, which have
rendered it popular with men and mast«ra in Cornwall and else-
where. The man's pay does not depend solely upon his muscular
exertion, but also upon his judgment. He exercises bia wits, ha
On tinstnfi prodaolng ij % (or lasa) of " black tin,"
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644 ORE AND STONB-MINING.
observeG the iiatore of the ground, and notices what conditioiu
are moat favourable for ore-bearing, such as colour and textun
of the surrounding rock ; what signs are the foreruoiierB of lichnetB
or poverty of the lode, such as intersections with " droppras"
or " feeders," joints in craiiain directions. 'the appearance of asso-
ciated minerals. Guided by slight indications of this kind, which
would pass unnoticed by the inexperienced, he is ready to back
his favourable opinion of a certain working place (jnicA) by
agreeing to work it at a price (tr^uU), which would seem quite
inadequate if one judged by the actual ore in sight at the time
of making the agreement. If he ia correct in his inference, he
may make a lai^ sum of money, and receive, for instance, one
fourth of j^aoo, instead of one-fourth of ;£5o, which seemed
probable from the original appearance of the ground.
This constant study of the geological features of the working
places and the calculations concerning the probable expenditure
for explosives and other materials, educate the minei-, make him
brighter, shrewder, and more self-reliant, and so raise him
mentally.
The advantages of this training are also felt by the mining
company; they have in the mine a body of expert detectives
constantly on the watch for clues to lead them to bidden ore-
bodice which might otherwise go undiscovered, and while the
tributer ia at work in any given "pitch," the mine-owner feeli
little fear of ore being thrown away in the rubbish, or of " waste"
being unnecessarily sent to the surface. As the interests of the
emplc^er and the employed are in these respects identical, tbe
former knows that littie or no supervision ia required on
his part to prevent loss from either of the two causee joRt
mentioned. The tributer is therefore left much more to himself
than the man employed upon tutwork. lAstly, it may be
pointed out that so long as the profit made out of each bargain
ie sufficient to pay its proportion ijf the general expenses id
pumping, ventilating, and management, the mining company
cannot lose by employing tributen. It is not to be wondered
that with these advantages the tribute system should be vaunted
to the skies by many mining engineers.
The other side d the picture must not be forgotten. In the
first place, the system is apt to promote duplicity among the men.
They are constantly endeavouring to outwit the agent by fur
means or foul, and will candidly confess that " the whole art of
mining is fooling the captain." The latter has often been a
tributer himself, and is fully alive to all the tricks which the
men are likely to practise upon him, auch as concealing any
indication of an approaching improvement, in order to get better
terms at the next " setting." This is not all ; it may happen that
two "pitches" not very far from one another are being worked
at very different tributes, one bargain being rich and the other
.vGooglf
PRINCIPLES OF EMPLOYMENT. 645
poor. One gimg may be getting two-tbirds of tbe value of the
ore th^ raise, the others only one-tenth ; the men with tbe low
tribute, that is to saj, the men in whose working place the ore
is abundant, are often ready enough for a consideration to part-
with some of their stock to their neighbouis, who transfer it
secretly to the " pile " which they ai« sending up to the surface,
carrying it perhaps from one working place to the other in an
improvised sock made out of a pair of trousers. The result is
that the sqoad with the high tribute are paid at a far better rate
for some of their ore, than the trouble of getting it watranted.
When the rates of tribute vary between narrow limits the case is
diSereut. For instance, the manager of a Eino mine was lately
paying 400. per ton for blende as the highest tribute and 30a. as
the lowest, which, with the ore selling at ^5 per ton, corresponded
to 8«. and 6*. in the pound respectively ; there was therefore little
or no temptation to transfer ore from one " pitch " to another,
and so defraud the company.
The training in trickery which is inherent to this system may
have its effect later on, when the tributer is promoted to a higher
position; front having been taught to consider that cheating
the captain is perfectly fair and legitimate, he may be ready to
conclude that "the whole art of mining is fooling the public."
And blunting of the moral sense of the men is an undoubted
evil.
Payment by tribute involves tbe necessity of ascertaining the
value of each gang's raisings separately. In the case of tin ore
(he percentage of casslterite is learnt by washing a sample upon
the vanning shovel, and from tbe result of this assay the total
amount is easily reckoned ; but with lead and sine each parcel is
dressed by itself, and the final lots of clean galena or clean blende
are weighed separately, before being mixed and made into heaps
for sale to the smelter. This multiphcation of small operations,
cleanings-up, and weighings, naturally makes the cost of dressing
higher than it would be if all the ore were treated alike, without
regard to the persons who had raised it.
Another objection to tbe ti-ibute system is that the lessened
amount of supervision for commercial purposes may tend to a
lessened amount of supervision for purposes of security; the
working place is not visited so often by the agent, and he has fewer
opportunities of pointing out to the men possible dangers from
want of timbering or other sources. The men sometimes court this
lack of supervision by making access to their " pitch " difBcuIt, or,
at all events, troublesome. Lastly, there is an element of gambling
involved in the tribute system, which it is scarcely advisable to
cultivate. The tributer is a speculator, who hopes by a lucky hit,
as comrades have done before, to make a lot of money in a
short time. Where one succecMJs in so doing, how many fail ?
According to the report of Lord Kinnaird's Commission in
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64<S ORE ASD STONE- MINING.
1864,* the tutworker at th&t time was bett«r hooaed than the
trihuter ; the moral of this is that, on the whole, it is better tar
the working miner to be io receipt of fairly conetant regular
wagea than to trust to the chance of occasional runs of luck.
Xbe advantageB accruiag to a mine from the tribute system are
far le«8 marked when there ia a lode of pretty even character, than
when the deposit is fitful and uncertain in ita nature. This
explains, to some extent, why the tribute system occupies a lees
im^»ortant place in Cornwall now than it did in the first half of
this oentuij. Cornish mines at the present day are mainly
dependent upon tin lodes, in which the caasiterite is finely dis-
seminated tluvugh a hard close-grained rock. The consequence
is that it is impossible to do much picicing underground, or indeed
at the surface ; the whole of the stuff raised from the stopes has
to be sent to the stamps. For depositn of this kind it ia more
advantageous to employ the tutworaer, who ezoavates the ground
at so muoh per fathom, than the tributer. Fifty years ago things
were different ; copper was then the mainstay of Cornwall, and
the chief ore was chalcopyrite. While cassiterite is a mineral
well adapted for dressing by water, chalcopyrite is not ; it cmmblea
to dust very easily, and the fine particles are liable to be washed
away with the refuse. A large amount of hand-picking was
required, in order to save as much of the ore as possible from
tr^tment in water. The care of the tributer in the stopes of
copper mines was a matter of vital importance in the old days,
and his services were really valuable.
Wbere an old mine is re-worked after a period of abandonment,
the tribute system often does good service, especiaLy if the object
is to recover some mineral considered worthless in former times,
or when branches of ore exist in the sides, after the main part tS
the vein has been removed.
In a like manner it proved a valuable remedy f in the Eureka
district for evils which had resulted from the plan of working
the ore by day labourers. The ore occurs in belies of irregular
shape and size ; men working by the day had not been careful to
get out as much ore as they might have done, and others were
induced by the tribute system to extract the portions remaining
behind, which would otherwise have been lost altt^ether. Besides
which it was known that small ore-bodiee had been passed over as
too poor or too insignificant to be worth removing in the ordinary
way, bnt which were quite good enough to afford a scope for the
talents of a man who had a direct interest in the ore he got out.
In 1881 the men received {2'5o for all ore assaying $30
* Beportofthe OamaUtioneri mpointed to Jnqvire into tie Oondiiion of
oH Minu tn Grtat Britam to whuA tht Prouuioiu of the Ad 23 d: 24 VieL
c 151 do not apply.
f Curtis, " The Silver-lead Depoaiti of Eureka, NeTada," Moti. V.S. Oai-
iiuTVty, ToL viL, Wafhington, 1S84, p. 151.
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PEINCaPLES OF EMPLOYMENT. 647
per ton, and 50 per cent, of all that it assayed above $30. Thus
an ore wortn 865 per ton brought to the tributer $2*50 +
ti7'50i o^ $>o- ^ cases of this Mod the servicen of t^e
tributer are often requisitioned with good results to the mine ;
that is to say, when the greater part of the ore has been extracted
by EOme other method of payment, and when more judgment and
care are required to ferret out and take away partly hidden
treasures distributed here and there in the workings.
Under the old Gomish syatem. of tribute, the partners are all
working men, who are all employed in the particular " pitch "
assigned to them ; but in Colorado one meets with a modification
of the method, in which the actuaj miner avails himself of outside
aid, and may or may not em^oy labourers who have no interest
in the adventure. A party <a miners who have confidence in the
future resources of some part of a mine, take it upon lease and
obtain the assistance of shopkeepers or others in the neighbour-
hood, in order to buy tools, explosives, and materials, and to
have moans of living during the unproductive stage of the under-
taking. If the hopes of the miners are realised, the sleeping
partners receive a share of the profits; if the speculation turns
out badly, the miners have bad a l»re subsistence, and the
petty capitalists lose their money. This system has the advantage
that it enables a certain amount of dead work to be combined
with the extraction of ore. Under the Cornish system working
men will not drive levels and sink shafts in unproductive ground ;
because, however high the tribute may be, they receive nothing so
long as they raise no ore, and they cannot afford, on their own
resources, to spend weeks and months in making the preliminary
openings, which may be required before some given block of
ground is made ready to yield up its supposed riches. A
Uttle outside capital tides the workers over their difficulty, and
■ givee them a chance of making money by the exercise of their
brains as well as by the expenditure of their muscular strength.
The question will be asked : How does the small capitalist guard
himself against the risk of having to provide for the living of
some lazy miners, who, hidden below ground, are merely making
a |a«tence of working t In the first place, he may take a pre-
caution, often omitted by the large capitalist, of associating
himself only with men whom he knows and can trust, and
secondly, as he is frequently a bit of a miner himself, he visits
the mine from time to timc^ and watches the progress of the
work.
The mine-owner favours this system, and even becomes a
partner himself, because he gets some of his dead work done
without any risk to his pocket. In the case of mines drained by
adit-levels and swept through by natural draughts, as is commonly
the case in Colorado, the mine-owner is put to no cost whatever
forpumping or ventilation, and therefore he losee no money even if
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64$
ORE AND STONE-MINING.
the " lease " turns out a failure, wbereas he is bound to be a
gaiuer if an; ore is met with.
The following are two actual examples which explain the
system very dearly : —
COLOKADO LeA££.
ProJUaUe Lteue to both Company and Luaet. Company or Ovnur
having ^ intterett, and Lamt \ interttt.
LUSK AOOOUNT.
'. 30. To Lmsm'b wigea
„ Ocher «Bge« .
„ SappllM, powder, Ac
„ 151 oresaoki .
„ HoistlDg, training, JLC,
„ Blacksmithing ,
„ Hauling oie to mill
By Proceeds of ore
ToBojalty .
3. 30. „ Lessee'g wagei
„ Other wBcea .
„ Powder, fote, feo. .
„ Hoisting, training, Ac.
„ SlaAksniithing
Haulir'"' "'" *" »«*t
By Proceedi
To Royalty
19.25
9955
17.25
36.00
Lessee received :
Wages for hia labonr
\ of profits
Company or onuer recelTed :
Royalt?
j of profits
Cost of work exolneive of lessee's labour
Total
316.40
2855.25
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PRDTCIPIEa OF EMPLOYMENT.
GOLOKADO IiEASB.
Oujnet 4 Inienat, and Zewee
J Intertet.
LKAaS ACCOUltT.
Dr.
Cr.
% c.
* c.
Sept. 30. To Leuee'B wBgsB .... 117.00
„ Other waget .
442.30
„ FowdsT, f nse, &.O. .
Stt3o
„ Hoisting and trainloK
07.85
„ HaulinK ore to mill
By Procoeda at ore .
"6.95
1321.60
ToEojalty .
660.80
Oct. 31. „ Lewee's wagea
117.00
„ Oth«T wa«M .
„ Powdar, ^in, &o. .
483-90
25. IS
„ HoiatiDg and uainiDg
66.9s
Han ling ore to mill
16.6s
„ looorenoki. .
'7-3S
Hj Proceeds of ore
1070.20
To Royalty .
535- 10
Not. 30. „ Leuee's wages
121.20
„ Other wages . .
314-30
„ Powder, fnae, *o. .
44- SO
„ Hoisting and training
67.60
„ Hanling ore to mill
9.20
By Proceeds of ore
To Royalty . .
661.30
3846.60
3714-40
Low on lease
i3a-2o
Thus the lessee ivoeived :
His wages for working amoimlillg to
Less half loas on tea«e
Leaving him for hia work
Lw ball loss 01
Net profit by the Company
i8s7.»
66.10
$1791.10
The mea who are ezcavating alate rock (roci-ffwn), and
tboee who are subdividiug it into merchantable slates (gvarrj/-
men), in the Festiniog district, are paid by a method which
in principle reeembleB the tribute BTStem. The eamingB of
the men depend upon the value of the stock of merchantable
slate which they obtain from their working place or " bargain."
At the end of the month the stock of each partnership is counted.
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650 ORE AMD STONE-MINING.
and the men are credited with the value of their make acoordin^
to a fixed taii£r. Thus, for instance, we may auppose that the
men had made fourteen hundred alatee of the size 24" x 14", at
37a. 6d. per thousand ; for this their acoount would be credited
with ^i i8s, 6d., and so on with each size. On looking down
an aoDount, it will often be found that the men have made " beet "
alatee of twenty different merchantable sUes, to say nothing of
Beveral kinds of " seconds." The total of these various items is a
first basis of the amount due to the partnership ; but as the
" rock " varies in quality in the different working places, owing to
the preeence or absence of joints, the interference of quartz veins,
or alterations of texture, the result of a given amount of
labour must necessarily vary also. In good rock the men will
make a large quantity of " best " slates of large sizes ; elsewhere,
though working equally hard and excavating quite as many cubic
feet, they will be able to make only slatee of small sizes, or
"seconds" in the place of "beste." The companies find the
simplest method of adjusting these differenoes is to pay a premium
or allowance, varying with the quality of the rock in each
" bargain," and determined at the " letting," i.e., at the time of
making the contract. A " bargain " may be let for a month or for
several months. The premium is called ** poundage."
Thus to take an actual case :
Total . . j£as 8 7
The " poundage " of io«. means a premium of Joe. in the pound ;
for every pound's worth of slate at tarifi* prices, the workmen
receive an additional half-sovereign; in other words, the value
of the total make is reckoned at 50 per cent, more than the
tariff prices. If the bargain is a good one, the poundage will be
low ; if the rock deteriorates in quahty, the poundage will have
to be raised at the next letting.
Another example will make this plainer :
£ '■ d.
Total . . £26 2 7
These two amounts, j£a$ Bg. "jd. and ^£26 za. 71^., are the
gross earnings, in each case, of four men for a month, and are
subject to deductions for materials supplied.
In the former case the deductions were : explodves, 6s. 6d.,
fuse, la., candles, 44., smith, 5s. iid., or 174. ^d. in all, leaving a
balance of ^24 iig. ad. which was handed to the men. In wis
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PEINOIPLES OF EMPLOTMEare.
651
bargain there vrere three partners, who employed & laboaror, and
worked twenty-four days. The company leaves the division of
the money to the men themBelves, but keeps an account so as to
know precisely what the earnings are. The recognised wages
of a labourer at Festiniog were 49. 2d. a day, so the labourer was
paid j£^, i.e., twenty-four times 4». id. iSiere remained, there-
fore, a net balance of ^iq IIS. 2d. to be divided among three
men. According to the time-book, these men worked 70J days
between them, and therefore their average wages were $8. 6d.
per man per day.
In the other case the accoont stood thus :
£
-
a.
Omu eandnKB
26
2
13
7
8
Dbductions.
Powder ....
Blasting gelatine .
Kuw
CandlM ....
Smith
Net balance
, 1 ..
j 'I
d.
6
6
4
£
M
8
■■
Here there were four partners and no labourer; th^ made
94 days between them, or at the rate of 5«. 2d. per man per
day. In spite, therefore, of the very great difference in the rock,
the poundage was bo fixed beforehand as to enable each set oi
men to earn very nearly the same wage per day.
At Festiniog the partnership commonly consists of four per-
sons: two working below ground, and engaged in getting the slate-
rock, and two working above ground in the mills, engaged in
making the blocks into merchantable slates. The reason for this
arrangement is the fact that the yield of slate from any given
block depends very largely on the skill of the dressers, and if the
splitting and making of the slates were confided to men paid by
the day, theee would have no interest in doing their beet with
the material delivered to them. Now the men working below
ground can rely upon their own partners to work up the blocks
into slates with tjie least possible loss ; the case is a totally
different one from dressing a metallic ore. Owing to the
nature of the substance which is being quarried, the payment by
a varying " poundage " is free from some of the objections which
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«S» ORE AUD erOKE-MINING.
Kn inBeparable from the "tribute" sytAem at <xe minee. At the
Utter the change ia the value of a lode may be bo Gudden, that a
single blast will convert a " pitch " originally " set " at & tribute
of two-thirds, into one which could be worked profitably by the
men at one-twentieth. If auch a change takes place some time
before the end of the contract, the men raise far more ore than
was thought possible when the bargain was airanged, and make
what is known to Comishmen as a " start " or " sturt," in other
words " a big haul." Gases are known in which a par^ of
tributers have earned as much as ;£ioo each in a month, instead
of the expected ^4 or ^5. The posaibihty of such good fortune
naturaUy encourages the miner to take the risks incident to work-
ing upon tribute, and at the same time prompts him to deceive
hia superiors if he can. With slate, the "rockman" may be
favoured hj unexpected jtants, and he may be able to earn twice
as much as was expected when he entered into his contract, but
he does not get twenty times as much, nor is he liable to find his
" bargain" so suddenly bectmie poor or absolutely worthless aa
may happen with a copper lode in Cornwall. There are also
fever opportunities of hiding coining improvements from the eyes
of the agents. The result is that there are fewer attempts at
concealment, and consequently there is lees chance of the moral
feeling being blunted ; sudden great variations in the earnings are
rare, and the solutiou of the problem of payment by results seems
very satisfactaiy.
As a final instance of the payment of wages, may be mentioned
that of piecework combined with premiums for good conduct.
This system was introduced at the large stone quarries of
Quenast in Belgium * in order to make the men stick to their
work during the regular hours, and not absent themselves on the
pretext that, as they were paid by results, they could do as they
pleased. The company instituted a higher rate of wages and
prices applicable only to men who did not leave the quarry
during working hours without permission. The men soon dis-
covers that it was to their advantage to get the higher tariff,
the public-houses were lees frequented, the average earnings
increased, and the company had more work done.
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( 653 )
CHAPTER XV.
LEGISLATION AFFECTING MINES AND QUARRIES.
Onnersblp — Tazatton — Woiking TegnlSitions ; HetalliferouB Mines B^ula-
Uone Acts, 1S72, 1S7S, tmd 1891 ; Cool Mines R^iilatiaa AoC, 1S87 ;
Alkali Acts — Boiler Biplosioni Acts— Brine Famping {CompenBatiotl
for Bubaidence) Act — Elementaiy Edacfttioo AcU — BmploTers'
Liability Act— Eiplosive* Act ; Factory and Workshop Acti — Quarry
Fencing Act^^Rivers PoUation Freventlen Act— Stannaries Act, 1S87 —
Truck Acta.
Thz object of thia chapter is to call the etudent'e attention to the
princijnl laws affecting the working of mines and quarrieB in the
British Isles.
The subject ma; be taken under the following heads :
I. OwTtership.
3. Taxation.
3. Working regnlatloni.
4. Soudry special statute*.
I. Ownership.— In the United Kingdom the peison owning
the surface is priTnd Jaoie entitled to all the minerals under-
neath, excepting in the case of mines of gold and silver, which
belong to the Crown. The Crown, however, does not claim gold
and silver extracted from the ores of the baser metals. Thug we
find that the Crown receives a royalty for the gold extiHcted
from auriferous quartz raised upon private property in Wales,
but gets nothing whatever for the sUver contained in argenti-
ferous galena.
The ownership of the minerals can be, and often is, severed
from that of the surface, the latter being sold whilst the mineral
righta are reserved by the original owner. Minerals lying under
the surface between high and low water mark are claimed by the
lord of the manor, while everything under the sea and beyond low
water mark is the property of the Crown.
Id the majority of casee in the British Isles,* the proprietor of
the minerals does not woi^ them himself, but concedes the right
* Fintd Report of the Boytd Comtrauton imointtd to Inquire xiUo the
M^ject of Mining Soyaltie*. London, 1893. This Report containa mnch
inAinnation also about the Hilling systems of the CoIodIm and foreigb
ooimtiiea.
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6S4 ORE AND STONE-MININQ.
to another peraon in return for an annual rent and a royalty.
Uaually a certain miniimim rent is fixed, whicli ha« to be pud
even U no mineral is being raiaed, but this rent merges in the
royalties ; that is to say, the amount paid as royalty is put to the
-credit of the rent, or, if sufficient, covers it eotirely.
The royalty may be :
(a) A fixed earn per acre worked.
{bj i. fixed Htun per ton laiBBd.
(cj i. flsed proportion at the valne of the mineral nused.
[d) A varjing proportion at the valne of the mineral sold, Tsgnlated
bj a wcUDg •cale.
The first prindple is more especially adopted in the case of
«oal ; on the other hand, a fixed rate per ton is common in the
caee of stratified ironstone. Id the Cleveland district, the royalty
is 6d. per ton on an average, and the leases extend for 43
yeara.
Mineral veins are generaUy worked upon the third system;
rcrjralties vary from one-tenth downwards, though this amount is
quite exceptional. It is not uncommon for the lessoe to pay one-
eight-eenth or one-twenty- fourth as royalty, and if a mine U
struggling against low prices of metal, Uie "lord" ia often
induced to abate his le^ claims very considerably, or even to
agree to forego all payments until trade revives. The royalty b
-calculated upon the ore mode ready for the market. Thus, for
instance, in one of the reports of Dolcoath mine in ComwoU we
read:
j£i8,6t6 16 I
Leases in Cornwall are usually granted for 21 year& The
lessor stipulates that a certain number of men shall be kept con-
stantly at work. Ground for tipping rubbish has to be paid for,
and sometimes at extravagant rates. When a lease is drawing to
a close, a new one is usually granted upon terms at least as
favourable as those of the old ones; but cosee have arisen in
which the "lord" has required a heavy premium before he would
grant a new lease.
The luematite of the Oarbonif erous Limestone of Oumberiand
and North Lancashire is usually leased upon a sliding scale,
which increases the proportion paid as royalty when the price of
ore goes up. Thus if iron ore is selling under 9s. per ton the
lessor receives lod. per ton as royalty, i.e., exactly one-tenth if
the price is 8s. 4d. Supposing the value of the ore to rise to 14s.
per ton, the lessee would have to pay as. or one-eeveoth. With
intermediate prices the fraction might be one-eighth or oue-nioth.
The leases are for 2 1 years.
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LEGISLATION AFFECTING MINES, ETC. 655
Many centviriefl a^ the Crown claimed the right to all
minerols, and, in order to promote mining, privileges were
granted to persons who would endeavonr to diacorer and work
mines ; from these privileges and from old usages have resulted
special mining rights peculiar to certain districts. Those per-
taining to Derbyshire have now been definitely fixed by two
special Acts of Parliament, the High Peak Mining Oustoma and
Mineral Courts Act, 1851 (14 & 15 Vict. c. 94) and the Derby-
shire Mining Customs and Mineral Courts Act, 1852 (15 & 16
Vict, c 43). Again, there are two special statutes (i & 2 Vict. c.
43 and 34 <fe 25 Vict. c. 40) which regulate the opening and
working of mines and quarries in the Forest of Dean, where the
" free miners " have certain peculiar rights.
These Acts are merely of local importance, bat they are of
interest as preserving old customs.
z. Taxation. — Mining companies have to bear their share of
Imperial taxes and local rates.* By " The Bating Act, 1874"
(37 & 38 Yict. c. 54) tin, lead, and copper mines are assessed on
the amount of dues payable, and in some districts a large pro-
portion of the rates may be paid by the mines, an arrangement
which is not unfair, if they are the cause of heavy burdens being
thrown upon the community.
3. Working Begulations. — We now come to the third division
of this chapter, viz., the statutory regulations which are in force
for the safe working of mines.
Special legislation for promoting the safety and well-being of
the miner is a growth of the last half-century. I do not mean
by this that there were absolutely no reflations in days gone by ;
there were rules which had grown up in some places, from customs
and privileges so carefully preserved that they had become laws,
but these related mainly to the acquisition and preservation of
mining property, and only incidentally to the prevention of
accidents.
In order to moke the state of our laws clear, and especially to
those who may be accustomed to Continental regulations, it is
necessary to point out once more that the sources from which we
obtain minenls are of three kinds :
a. Open works, that is to say worMngs open to the sky.
h. Mines, that is to say workings carried on underground by
artificial light;
c. Bcareholes, or old flooded mines, from which brine is
pumped.
As was said in Chapter I., it is the nature of the ezcavatdon
and not the nature of the mineral, which settles, in this country,
whether a given working is a mine or not. Consequently it must
Fuliamentaiy Paper No.
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656 OBB AKD STONE-MINING.
be nnderstood that the purely mining Acte in no way effect open
workiiigs, save euch as may form part and parcel of a true mine.
The actual raining etatutea now in force are as follows, is
ohroaological order :
The Metalliferous Mines Regulation Act, 1873 (35 & ^6 Vict.
e-77)-
Tbe Metalliferous Mines Begulation Act, 1875 (3^ ^ 39 ^ict.
«- 39)-
Hie Slate Mines (Ounpowder Act), i88z (45 Vict. c. 3).
The Coal Mines Eeguktion Act, 1887 (50 & 51 Vict. c. 58).
The Metalliferous Mines (Isle of Man) Act, 1891 (54 & 55
Vict, c 47).
The first of these Acts was passed after the report of the Boyal
Oommission appointed in i86atoiDquiTeintothecondition of mines
which were then not undw inspection, and it was mode to embrace
every mine to which the sister Act, the Coal Mines Act of
1872, did not apply. Therefore evety mine in the kingdom ia
under inspection : either it is subject to the provisions of the Coal
Mines Act, 1887, which has taken the place of the 1872 statute,
or it is under the Metalliferous Act of 1873. The former Act
applies to mines of coal, stratified ironstone, shale, and fire-clay,
and therefore the latter takes cognizance of everything else. The
titles of the two Acts are misleading. Three times as mndi iron
ore is obtained from mines under the Coal Act aa from mines
under the Metalliferous Act, and the largest mine under the
latter does not produce metallic ores. Boon after the passing of
the Metalliferous Act, the owners of an underground slate quarry
in North Wales refused to have their workings treated as miner.
ThOT asserted with some plausibility that the Statute was the
" JletailiferovM Mines Act," and that their workings had invariably
been known as " quarries," and never as " mines." The matter
had to be brought before the Court of Queen's Bench, and there
it was speedily decided that, in spite of popular phraseology, the
Featiniog underground quarries were legally "mines," and, as
such, subject to iospectiou, quite as much as the Cornish tin mine,
the Cumberland iron mine, or the Derbyshire lead mine.
I will now proceed very briefly to pass in review the most
salient points of these two Acte of Parliament, beginning with the
simpler, and incidentally point out the slight modifications intro-
duced by the other three statutes mentioned in my list.
The Metalliferous Act is divided into three parts.
Fart I. deals with employment of women, girls, and boys. No
females can work below ground, nor can any boy under 12 years
of age. Boys under 16 cannot be employed more than 54 hours
in any one week, or more than 10 hours in any one day.
The person in charge of machinery for raising and lowering
men must be a male of at least 18 years of age.
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LEGISLATION AFFECTING MINES, ETC. 657
Wages must not be paid in publiohouses.
An Annual Return has to be sent every year to the loBpector
of Mines of the diatrict, specifying the number of personii em-
ployed, and the output of mineral. Under the 1872 Act, the
mine-onner was not obliged to furnish this I'etum for any given
year until ist August following. This delay in the deepatch of
the return was manifestly absurd, for the statistics based upon
them could not be published until they had lost much of their
interest; the fault in the 1873 Act was corrected by the short
amending Act of 1875, which changed the date from the ist
August to the ist February every year.
The owner* or agent has to send to the lospeotor of Mines of
the distriet notice of every fatal accident, of every accident causing
serious personal injury.and of every accident, no matter how trifling,
causing personal injury by reason of any ezploeioa of gas, powder,
or of any ateam-boUer. The word ' ' serious " gave a little trouble
at first. Some agents were inclined to interpret it as meaning
" likely to prove fatal," and did not report broken arms and legs,
because there was every reason to suppose that the man woiUd
recover. Nowadays, when the period 6t disablement ia likely to
exceed a week or ten days, the accident is usually notified.
Notice of opening, discontinuance, recommencement or aban-
donment, has to be sent within two months.
The section which follows (sec. 13) is one which was very much
wanted, and which is still often called into requisition. It is the
portion of the Act which provides for the secure fencing of shafts
and side entrances of mines which are no longer at work. In
working mineral veins, the " old men " sank their shafts as close
to one another as they still do in mining ozokerite at Boryslaw,
and the surface of open and uninclosed land was often riddled
with holes like a sieve. If the tupe of thane shafts were in hard
rock or were lined with stone, they remained open, and were a
source of danger by day and by night, for many were cloee to
roads or foot-paths, and, when partly or entirely concealed by
brambles or bushes, they formed veritable man-trap. In other
cases the timber lining at the top had decayed and the ground
had run in, leaving a huge yawning crater, 10 or 20 yards across,
leading to a pit hundreds of feet deep. It is true that a visible
danger of this kind was known to the inhabitants of the district
and could be avoided by daylight, but strangers were exposed
toa considerable amount of peril. EHve and twenty years ago the
state of some of the open commons in Cornwall and Flintshire was
simply scandalous ; and even now there are often good grounds
for complaint on the part of the public, as fences become defective
from having been constructed origimUy in too flimsy a manner, or
" The word "owner" has a special interpretation wider the statute
and refers to the lessee or company working the mine, and not to the pro-
prietor of the BOU or mineral rights.
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658 ORE AND STONE-MININa.
fmrnthemischieTOuapraiikBof passers-l^. Occasiooally, too, &n un-
known eh&ft comee to light from the decay of the platform (^
planks which had been put over it and covered with earth when
the mine waa abaadoned. If treated in this way the top sood
becomes grown over with grass, and recollection of the ehftft
gradual!}' fadee away. These timber " sollare," as they are called,
should never be put in unless there is also a secure fence. Many
narrow eecapes have occurred in Cornwall from the giving way
of such coverings, where the presence of a shsit whs quite un-
Abandoned mines are not only a source of danger to the
general public by creating pitfalls, but they may also threaten
the woi^ere in the vicinity by holding accumulations of water
or gas, liable to be tapped unexpectedly if the boundaries
of the old workings are not known. To guard against such
posEdbilities, the owner, who is bound to keep an acciirate pUa
and section of his mine daring the progress of the woilsiigs,
is further obliged to deliver up a copy when he abandons them ;
these plans are filed at the Home C^Sce, and can be consulted if
necessity arises. They serve also to show new-comers, who pro-
pose to reopen an old mine, what work has been done by their
predecessors.
The next section of the Act relates to the Inspectors of Mines,
who are appointed by the Secretary of State for the Home
Department. The Inspector may not practise as a mining
engineer, manager, agent or valuer of mines. In addition to
enforcing the provisions of the Act, the Inspector has the right to
complain of any thing or practice in the mine which is
dangerous, or defective, or, in his opinion, threatens or tends to
the bodily injuiy of the persons employed. In order to prevent
an unreasonable Inspector from pushing matters too far, the
owner and agent are duly Bsieguarded. They can object to the
Inspector's notice about these alleged defects and have the matter
referred to arbitration.
Each Inspector has to make an Annual Report, which is laid
before Parliament and af toi'words published as a Blue-book.
This is a convenient place for explaining that the United
Kingdom is divided, for the purposes of inspection, into thirteen
districts, each under a Chief Inspector, who, as a rule, has from
one to three assistanto.
The following separate publications are issued annually by th&
Home OfiSce :
Report by each Inspector for his district.
Statistical Suromaries showing the number of persona em-
ployed, the deaths from accidents, and the quantity of
mineral raised, together with the correspondrng figures
for previous yeara.
List of all the Mines in the United Kingdom.
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LEGISLATION ATFECTINa MINES, ETC. 659
JAst of Record FlaoB deposited at the Home Office.
Mineral Statistics of the United Kingilom.
The laet section of Part I. of the Act refers to the duties of
the coroner, who cannot conclude an inquest upon the body of a
person killed hj a mine accident, unless due notice hss been given
to the Inspector of the district. As a rule the Inspector attends
the inquest, &nd can be of much assistance to the coroner in
eliciting evidence, for he will have seen the place where the
accident took place, and will know whether it is likely that it
has been causM by pure ill-luck or through neglect of proper
precautions.
Fart II. of the Act contains the General Rules, and aeta forth
the mode of establishing Special Rules.
The General Rules are a series of nineteen regulations which
have to be observed in every mine.
VentilaHon. — Rule i relates to ventilation. It prescribes that an
adequate amount of vfintilation shall be constantly produced, so that
the various parts of the mine shall b« in a fit state for working
and passing therein. No standard of ventilation is laid down,
nothing is said about the number of cubic feet per minute that
have to be supplied, nor as to any given percentage of noxious
gas rendering the ventilation " inadequate.
EssploMxe and Blasting, — Rule 3 defines how explosives are to
be t^en into the mine, and lays down the precautions which
have to be observed while they are being used. Storage under-
ground is forbidden ; the mine should have a proper magazine
above ground, from which explosives should be dealt out daily to
the miners in small lots as required. In order to save trouble in
keeping the account of the small daily doles, a subsidiary magazine
is sometimes kept up, in which each gang of men has a locker. A
proper attendant then serves out explosives every day from the
lockers, without weighing the quantities.
The explosives must be taken into the mine in a case or
canister which mnst not contain more than four pounds.
Iron and steel needles or prickers are prohibited, but the
Secretary of State has power to exempt mines from this
restriction if he thinks fit. Exemptions of this kind have been
granted in the case of the salt mines of Cheshire. Iron and steel
tamping bars may not be used for ramming in the wadding or
the firat part of the tamping. It is lastly illegal to pick out or
bore out the tamping of a charge of powder which has missed
fire.
Hy the Slate Mines (Gunpowder) Act, 1883, the Secretary of
State has power to relax the restrictions concerning explosives.
This Act was passed for the convenience of workers in slate mines,
who occasionally have to fire large blasts of S, 10 or 12 potmds
of powder, in order to sever a large block of slate which has not
been comfjetely released by the original shot. The powder is
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66o ORE AND BTONE-MININQ.
sometimeB required oa the spur of the moment, as w&ter might
fill up the crack by the time the man had mode the journey to
and from the surface for a supply. M&ny agente of ^te mines
are of opinion that it ia safer to carry powder into the mine in
the 35-pound kegs coming direct from tibs manufacturer than in
the ordinary 4-pound caniaterB. Where exemptions have been
granted under this Act, the dangers incident to storing these
kegs of powder and opening them by candle-light are reduced as
far oa possible by stringent special rules.
Indvned Plartet atid Sorte Roada. — Rules 3, 4, and 5 relate to
signals and refuge places on inclined planes or horse roads.
Shajia. — In Rules 6, 7, and S are very important r^ulaticma
concemiog shafts. The sides have to be made secure, and the top
of the shaft and all entrances to it have to be fenced.
DeaceiU and Ateent-^-Ths next seven rules relate to the descent
into mines and ascent therefrom, whether by ladders or machinery.
If ladders are used, the ladderway must be partitioned off from
the winding compartment. The object of such a partition is not
only to prevent men from falling into the winding compartment,
but also to protect them from stones, which might Aro^ from
the bucket or skip during hoisting operations. Vertical and
overhanging ladders are forbidden, and substantiat platforms
are required at intervals not exceeding 30 yards. The rule
also says that " a ladder shall be inclined at the most convenient
angle which the space in which the ladder is fixed adraite."
The wording is unfortunate, because it sometimes fails to secure
A proper inclination for ladders; there is nothing to prevent
a person from sinking too small a shaft, and then alleging
want of space as an excuse, when a complaint is made to him
about the great steepness of his ladders. The Belgian law is
worded better, for it says that no ladder shall be indined at an
angle of less than to° from the vertical.
The only statutory enactment about man-engines is that they
shall be partitioned off from the winding compartment of the
abaft.
We now come to ascent and descent by winding macJiinery.
Guides and signalling apparatus are required as soon as a shaft
exceeds 50 yards in depth, and a cover overhead is obligatory
unless an exemption has been granted by the inspector. A single
linked chain is forbidden ; the winding drum must be provided
with flanges to prevent the rope from dipping off; there must be
an adequate brake, and an indicator to show the position of the
load in the shaft.
Dnsting-room. — It was quite right on the part of the Legislature
to make provision by Rule 16 for a changing house, or " dry,"
enabling the men to change their clothes in comfort, and have
easy means of drying their wet underground suite ready for the
next day ; but the wording might have been a little more dastic
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LEGISLATION AFFECTINQ UINES, ETC. 66 1
Aa the law etandfl, a miae need not have a " dry " if fewer than
thirteen personH are employed below ground ; and yet one meets
trith wet sinking sliafte employing only ten or a dozen men,
where some accommodation is desirable, and with large mines
which are bo di^ that a changing house, as generally undergtood,
ia auperfluouB.
Fanoing Machinery. — Rule 17 prescribeB that all dangerous
machinery must be fenced.
Steam Boileri. — The only statutory regulations concerning
steam boilers are found in Rule t8, which says that every such
boiler must be provided with three fittings, riz., a steam gauge,
a water gauge, and a safety valve.
WU/td Damage.— Tb» last Rule, No. 19, forbids the wilful
damage of, or removal of fenceo or appliances provided for the
safely of the men.
In order to make the owner and agent responsible for the
proper carrying out of these essential regulations, this section of
the Act concludes with a very strict clause. As a rule, in this
country, a man is assumed to be innocent until he is proved
guilty. In mining, it is different ; if a contraventioti of the Act
by any person whomsoever, for instance, a workman, is proved,
the owner and the agent are each made guilty of an ofience and
are liable to punishment, unless they can prove that they had
taken all reasonaUe means to prevent the contravention by
publishing, and to the best of their power, enforcing the rules.
The Legislature has therefore taken strong means in order to
render the miner's calling safe. On the other hand, the owner
and agent are thoroughly safeguarded by a clause, which governs
the whole of the section, and says that the rules are to be
observed " so far as may be reasonably practicable."
Special Rules may be r^orded as by-laws framed to suit
the conditions of any particular district or mineral deposit;
when once established with the formalities prescribed by law,
they have all the power of the statute itself. They are a very
oseful institution, and as there are simple means of modifying
them, changes can be introduced from time to time, without
having to set in motion the ponderous machinery required to
alter an Act of Parliament. At mines under the Metalliferous
Act, special rules are not compulsory as they are under the Coal
Mines Act ; but the Secretary of State can propose any rules he
thinks fit to the ovmer of the mine, who may object and have the
matter decided by arbitration.
An Abstract of the Act, and a copy of the Special Rules (if any)
have to be posted up in a conspicuous place at the mine, where
they can be conveniently read by the workpeople. The name
and address of the Inspector of the district have to be appended,
80 that every one may know to whom to apply in case of need.
Fart III. deals with penalties for offences and the technicalities
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663 ORE AND STONE-MININQ.
relating to legal proceedingB. The pmaltiee to which a peraon
is liable for a breach of the Act are a tnaziiQuin of J^2o u he Is
an owner or agent, and a maximum oi £2 if he is an; other
person ; the fine may be increased by ^1 a day so long aa the
otTenoe continues, if the ofiender has received notice in writing
from the Inspector. Forwilful neglect, endangeringUfeand iimb,
A person may be sentenced to imprisonment, with or without
hard labour, for a. period not exceeding three months.
The owner and agent cannot be prosecuted except by an
Inspector, or with the oonsent in writing of the Secretary of
State. The workman can be prosecuted by his master; and
proceedings against the men become necessary when the master
finds that mere words fail to secure strict obedience to re^la-
tions, which is imperative in a dangerous oocupation like mining.
Strange to say, the clause which prevents interested magis-
trates from sitting in cases under the Coal Mines Act, is omitted
altogether in the Metalliferous Act.
Where a penalty amounts to or exceeds half the maximum, the
person convicted may appeal to a higher court.
The last Minlag Act, that of 1891, was passed in order to
correct a curious omission in the old statute of 1873, which failed
to define the Court of Sammary Jurisdiction in the Isle oi Man
before which proceedings could be taken.
Having thus briefly explained the statute by which the working
of many ore and stone mines is regulated, we must now paaa on
to the Coal Mines Begulation Act, 1887, which governs mines of
stratified ironstone, shale and fireclay, as welt as collieriee. Com-
pared with coal, it is true that these minerals are of minor import-
ance; but as their total output amounts to more than 13,000,000
tons annually, of which 7,000,000 tons are ironstone, it is
evident that even the ore miner should be acquainted with (^e
requirementa of this statute.
It presents many points of resemblance with the Metslliferoua
Mines Begulation Act, but it is far more elaborate in its details ;
to save repetition it will be beet to dwell more especially upon the
points in which it difiTetv from the Act which we have just been
discussing.
In Part I. the principal new features are :
Eov.r» of Li^our, — Regulation of the hours of labour of boys
and females employed above ground.
Check Weigher. — If the majority of the men wish it, they may
appoint a check weigher to see that the weighing is done correctly,
and that deductions are made fairly.
Prohihition of Single Shtifii, — The object ia to provide two
means of egress in case of accident ; certain mines may be
exempted from this provision.
Piviaion of Mine into Parts.— Under certain orcamstances
each part must be treated as a separate mine.
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LEGISLATION AFBUCTING MINES, ETO. 663
Certificaud Managers. — This is one striking difference between
the Metalliferous Act and the Goal Act. Under the former a per-
son without any pretanmons to professional qoalifications may be
placed in charge of a mine; under the latter every mine employ-
ing more than thirty persona below ground must have a certificated
manager. In order to obtain a certificate the candidate must
have bad pmctical experience in a mine for at least fire years, and
most then pass an examination. For the purpose of granting
certificates, boards for examination have been appointed in each
of the twelve districts into which the kingdom is divided for the
purposes of the Coal Mines Act. Unfortunately the statute makes
no provision for securing uniformity in the examinations, Evrat
the limits of age are not the same ; but, nevertheless, a certifi-
cate when once obtained, is good for any part of the kingdom,
Retwna. — The Annual Return which has to be fumisbed under
the Coal Mines Act not only gives the output of the mine and
the number of persona employed, but also supplies details con-
cemiag the mode of ventilation ; the part relating to the quantity
of mineral wrought cannot be published, save by consent of the
person making it, or of the owner of the mine. This restriction
prevents the publication of such details as appear in the " Mineral
Statistics " in the case of mines under the Metalliferous Act.
Inquetla. — At coroners' inquests, a relative of the person killed,
the owner, agent, or manager of the mine in which the accident
happened, and any person appointed by the order in writing of
the majority of the workm.en employed in the mine may attend
and examine witnesses, No such power is conceded under the
Metalliferous Act.
Part II., as in the other Act, contains the General Rules, and
regulates the establishment of Special Rules, which are compul-
sory instead of being vtduntary.
The General Rules are 38 in number, or twice us numerous as
those in the sister Act. They may be passed in revievr very briefly
as follows :
VentUaiiion (i, 3, 3). — Amount of ventilation to be adequate ;
quantity of air to be measured monthly ; special airway to carry
the return current clear of the ventilating furnace ; ventilating
machines to be placed where tbey will not be injured by explo-
Inapectvms by OffiaaU (4, 5). — The working place has to be
inspected before men begin thdr work, and during the progress
of their work. Machinery must be inspected daily and shafts
weekly.
FeTidng (6). — Dangerous places must be fenced off.
Wilhdrawai of Men (7). — Men must be withdrawn from
dangerous places.
Safetif-Lampt (8, 9, 10, 11). — Use, construction, and examina-
tion of safety-lamps. Situation of lamp stations.
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664 OUE AND STONE-HININQ.
ExpUmvu (ii). — Prohibition oF iron and Bt«el tools forchugiiig
holes, and special precautiaua for blasting in minee where fire-
damp has been noticed, or which are dry and dusty.
Advnwx BorthoU* (13). — These are made compulsoiy when
approaching water,
SignaUing and Man- ff oh* /(»■ Traveling Boada (14, 15, 16). —
Very like the rules in the Metalliferous Act.
JHmmmont of TrnvtUittg ifootb (17).— Here we find that the
comfort of animals is not forgotten, for roads must be big enough
to allow the horses or ponies to pass along without rubbing.
Fencing qfShttfU (18, 19). — Very like the rules in the MetaUl-
ferouB Act.
Securing of Sha/U {20). — Identical with the rule in theMetalli-
femus Act.
SeeurtTig of TVaveliing Road* (21). — This very useful role,
though contained in the C!oal Minea Act of 1872, was not iooor-
porated with the Metalliferous Act.
Timber (32),— Props have to be provided at a conveoieDt place
in the mine.
Daeent and Atcenl (23 to 30).— In addition to the regulationft
found in the Metalliferous Act, there is a rule preventing a speed
of more than three miles an hour after the cage has renohed a
oertain point in the shaft, when the winding apparatus is not pro-
vided with some automatic contrivance for preventing overwind-
ing. Men may use the downcast shaft for descent and ascent
if they wish to do so. So mention is made of ladders or man-
eoginea, which are not in use at mines under the Coal Mines Act.
Fencing Machinery (31). — Identical with the Bule in the
Metalliferous Act.
Barometer and Thermometer ^33). — Theee have to be placed In
a conspicuous position at the mine.
Ambulances (34). — As sufiering may be mitigated or life saved
1^ having proper appliances at haad for relieving and moving
injured men, the statute requires that stretchers, splints, and
bandages shall be kept ready for immediate use.
WHfitl Damage to Feneet, or Appliances for SafUy (35). — Very
like the rule in the Metalliferous Act.
Obtervaace of Dv'tcUona (36). — Men are bound to obey direc-
tions with respect to working, given with a view to comply with
the Act or Special Bulea.
Booka rteording HetuUi of Intpectiona (37). — These have to b&
kept at the office of the mine.
' Periodieal Intpection on BeAalf of Workmen (38). — The men
may appoint two practical working miners to inspect the mine, at
their own cost, once a month. The result of the inspection has
to be recorded in a book, and if the report states the ezistenoe or-
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LEGISLATION AFFECTING MINES, ETC. 665
i Workmen (39). — Men are not allowed to work alone
in getting coal or ironstone at the face of the workings unless
they have h&d two years' experience in or about the face of the
workingB of a mioe.
Fart III. relates mainly to legal proceedings, and the only
special point to which attention need be called is the section which
prohibitfi persons iut«reeted in mines, or their near relations, from
sitting on the Bench and adjudicating upon breaches of the Act.
4. Sundry Special Statutes. — It might be thought that
statutes framed for regulating mines would contain all that the
law requires for their safe and proper working ; but such is not
the case in this country. Miners and workers of open pits are
often affected by one or more of the following Acta of Parliament,
which are arranged in alphabetical order : —
Alkali, du;., Works Regulation Acts, i$8i and 1892 (44^45
Vict, c. 37, and 55 and 56 Vict. c. 30).
Boiler Explosions Acta, 1882 and 1890 (45 and 46 Vict, c, 22,
and S3 and 54 Vict. c. 35).
Brine Pumping (Compensation for Subsidence) Act, 1891 (54
and 55 Vict. o. 40).
Elementary Education Aots, 1870 to 1891 (33 and 34 Vict.
*• 75 ; 3^ '""' 39 Vict. c. 79, and 43 and 44 Vict. c. 33 ;
53 and 54 Vict. c. 22 ; 54 and 55 Vict. c. 56).
Employers' liability Act, 1880 (43 and 44 Yict. c. 42).
ExploeiveB Act, 1875 {38 Vict. c. 17).
Factory and Workshops Acts, 1878 and 1891 (41 and 42 Vict.
c. 16, and 54 and 55 Vict. c. 75).
Quarry Fencing Act, 1887 (50 and 51 Vict. c. 19).
Biyers Pollution Prevention Act, 1876 (39 and 40 Vict. c. 75).
Stannaries Act, 1887 (50 and 51 V^ict. c. 43).
Truck Acts, 1831 and 1887 (i and 2 WUliam IV. <;. 37, and
50 and 51 Vict. c. 46).
The Alkali AcU were passed with a view to prevent noziona
and offensive gases produced in manufacturing processes from
being discharged into the atmosphere, or at all events to reduce
their escape to a minimum. Theee Acts apply to a few mineral
workings — viz :
(l) Salt worka In which brine is being evaporated for the mauafko.
toie of Halt.
!3] Cement works in which oIbje are made into nement.
3) 1^ and copper mines where ores ooBtoinlng araenio are beinc
(4) CoUieries where tar and ammonlacal liqnor, obtained from the
waste gases of coke oTens, are being treated ; the foimer is dis-
tilled for tbe prodactioD of paraffin and boming oils, the latter
is made into sulphate of u '-
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ORE AND STONE-MINING.
the B<nlerE!cplogiont Acts compel tbe owner of a mine to rqMKt
to the Boai-d of Trade &ny exploeion of a steam boiln*, which m&j
happeo at bis works whether above or below grotmd. The Bo»zd
of Trade officials can then make a preliminaiy investigation into
the cause of the explosion, and afterwards hold a formal inqaiiy
if they think fit. The Court holding this fomud inquiry is
usually composed of two Commissioners specially appointed by the
Board of Trade, who ore endowed by the Acts with ample potrear
for punishing the owners and agents of mines, if an explosion b*s
in any way been caused by their neglect. The OommissitHiers
cannot inflict a " fine " in a ciiminal sense, such as is impoeed by
a Court of Summary Jurisdiction at proceedings token under the
Mines Begulation Acts ; but, where neglect has been proved, the
responsible persons have been ordered to pay as niudi as j^ioo
or;^i20 to the solicitor of the Board of iS^e "towarda the
costs and expenses of the investigation," which practically comes
to the same thing. Under the Miaea Regulation Acts the miao-
owner can appeal to a superior court and have the matter re-heard ;
but the decision of the Commissioners underthe Boiler Explomons
Act is final and not subject to review.
The Srin« Pitmping Act provides compensation for owners of
property who suffer through the subsidence of the ground caused
by the pumping of brine. The working of the Act is controlled
by the Local Government Board.
The EhmerUary Education Acts make provision for the edoca-
tion of children : they prohibit absolutely the employment of
children below the age of lo, and do not permit the employment
of children below the age of 13 unless they have reached the
standard of education fixed by the by-laws in force in the
district. Children between 13 and 14 are allowed to work if they
can produce a certificate of proficiency or of previous due attend-
ance at school. After they have attained the age of 14, they axe
no longer " children " within the meaning of the Education Act&
The Employeri' lAahUity Act extends andr^ulates the liability
of employers to moke compensation for personal injuries suffered
by workmen in their service. Until this Act was passed a work-
man could not claim compeugatioo for injuries due to the neglect
of a fellow-servant. The statute of 1880 has broken down this
doctrine of " common employment " to a certain extent, and has
made the master liable if the injury was caused by the negligence
of a foreman or person entntsted with superintendence ; but it
does not make the master liable for the negligence <^ all the
fellow-servants.
The ExplotivM Act regulates the manner in which licences for
storing explosives are obtained, the construction and maintenance
of the magazines at mines, the subdivision of the trade p
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LEGISLATION AFPECTING MIXES, ETC. 667
and the delivery to the men. The Act is eaf oroed by Inepectois
under the Home Department, and also by the Police on behalf
of the Local AathoritieB.
The two FoBtory and Woriahop Acta, which are enforced by
InfipectoiB serving under the Home Department, apply to certain
quaniee.andtoBurface works at minea under the Metalliferous Act,
iiucb aa the dreeemg aheds. They contain provisiona for promoting
the health and eafety of the workpeople, and regulate the hours
of employment of women, young persons, and children. It ia
probable that all quarries will eventually be placed under the
aupervisioD of the Inspectors ot Mines.
The object of the Quarry Fencing Act is evident from its title,
and it is the business of the Local Authoritise to see it enforced.
By section 5 of the Eivert PoUiUion Frevmtion Act, the mine-
owner is prohibited from discharging into streams any solid
matter in such quantity as to prejudicially interfere with its flow,
or any poisonous, noxious or polluting solid or liquid matter,
unless he proves that he is using the best practicable and reeson-
ably available means to render such matter harmless. The
administration of this law rests with the Sanitary Authority of
the district, and in this, as in other matters, the work of the
Sanitary Authorities is supervised by Inspectors acting under the
Local Government Board.
The large amount of refuse which is produced in extracting
some minerals from their ores, makes the task of getting rid of
it, without polluting the rivers, far from easy ; and the miner
often incurs the wrath of the fisherman, who stirs up the
Sanitary Authorities or Biver Conservancy Boards into action.
Coarse waste, such as comes from jigging the larger azea of
the crushed rook, can always be made into heaps upon the
land ; but the fine slimes, whether coming from stamping or
other dressing processes, are carried away in suspension, and turn
a bright trout stream into a muddy dnun, or are spread over the
meadows in flood time, to the annoyance of the farmer. These
evils may be greatly lessened by providing large pits into which
the water from the mine is allowed to settle, and so deposit much
of the solid matter which it contains in suspension. Effective
filtering pools have been made in Germany from the coarse
refuse (akimpinga) from the jigs. It is tipped so as to form
high banks encloeing a rectangular area, into which the muddy
water from the " floors " is led, and allowed to form a large
pool. Some of the solid matter settles down on the bed of the
pool, as it would do in any ordinary pond, and the rest is depomted
in the bank itself, as it permeates through the tortuous passages
left between the little fragments of stone. In time, the inner
sides of the banks become somewhat choked with slime and the
percolation no longer proceeds so rapidly; this state of things in
remedied by letting out the water during a holiday, and scraping
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668 ORE A2fD STONE-MINIHa
down the ndes, so u to ezpoee & fr«eh uochoked surface to tbe
Blimj mtor. Old he&pe of mine refuse can be utilised in »
aimiur nuumer ; tbe stream of dirty water led into the top will
escape fairly clear at tbe bottom. As soon as one part of the
heap becomes choked with slime, the oat-fall of the " floora " must
be uiifted to another part of the bank.
Tbe Stannariea Act, i $87, was passed to remedy certain evils of
wbidi miners and shareholders complained at mines in Cornwall
and Deroo. The Act extends only to metalliferous mines and tin
atreamlng works — *.«., works where tin ore is extracted from the
dirty water flowing away from mines, within the Stannaries.
The miner now has a first charge upon the propotr of a "lining
company, and is less IJkely to lose his earnings when a mine is
stopped for want of funds, than he was some years ago. Surface
hanOB have to be paid onoe a fortnight; miners employed by
contract below ground are entitled to daim " subeiBt " once a
fortnight — that is to say, a payment on account equal to the esti*
mated amount of their earnings. Money deducted for aick and
accident funds has to be accounted for, and a oopy of the balance-
sheet must be posted up in the " dry " or changing house. The
miners have the power to appoint a check-weigher. Meetings of
the sharehotden of every " cost book " mine must be held at least
ODoe in every sixteen weeks. Tools and materials supplied to the
minera have to be charged as nearly as possible at the market
prices. Other regulations relate to the settlement of disputeSr
mortgages, relinquishment of shares, and registration of companies.
A oopy of the Act has to be kept posted np in the smith's shop
and in the changing bouse of every mine.
The object of the Truck Acta is to prevent the mine owner from
making a profit out of the tools and materials which he supplies
to his men ; but he has a right to make deductions from the men's
wages for medicine, medical attendance, materials and tools, pro-
vided that they agree in writing to this system. As a rule the
men would sooner obtain the necessaries for their work in this
way, than purchase them at the shops in the district. The
Truck Act« have to be enforced at mines by the Inspectors
under tbe Mining Acts.
Worn the foregoing pages it is very evident that the manager
of a mine in this country may have to make himself well acquainted
with a considerable number of legal enactments, mostly of recent
date, if he desires, as he should do, to carry on his work in strict^
aooordance with the law.
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{ 669 )
CHAPTER XVI.
CONDITION OF THE: MINSK.
It is perfectly impossible to do justice to the importsDce of this
subject in the fetr pages that can be devoted to it io a. general
text-book; but the following remu-ks will serve to call the
attention of the student to matters with which he may have to
deal when he enters into the active duties of his profession, and
becomes either an employer of labour himself, or the agent of a
milling company.
I propose to treat the snbject under the following heads ;
t. Clothing.
3. HoQBing.
3. Bducaticin.
4. Bicbieaa,
5. Thrift.
6. ReoreatfoD.
I. CIiOTHIlTa. — At the surface we clothe ourselves in order
to keep onr bodies worm, and to protect ourselves from the sun
.and rain; in the mine the conditions are totally difierent, and the
clothing may be altered accordingly. On the whole the tem-
perature is more uniform than it is above ground ; the miner in
most oases finds his working-place warmer in winter and cooler
in summer than it would be if he were working in the fields in
the neighbourhood. It is the exception to have the temperature
below 32° F. in mines even in winter. Occasionally in this
country a freezing wind rushing down the abaft will coat the
Udders with ice and make climbing unjtleasant and risky, and
where the climate is cold and the openings to the surface la^o*
the efiecta of frost are felt far deeper thui they are here. "&.»
sinkings through alluvial deposits in Siberia are iostances of
great cold in mines ; and even where the operations are more
truly underground the temperature is sometimes below freezing
point. This is the cobs at the Algachi silver mine.t
The other extreme was found in the workings on the Comstock
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670 ORE AND STONE-MINING.
lode.* In the year iS68, when a depth of looo to i2cx> feet Iiad
been reached, the heat in some drifts was becoming nnbeorable.
In August 1868 at a depth of 1 100 feetin theChoUar-Potosi Mine,
the temperature was 100° F. (37*7 C), and in the lovrer level of the
Hale and Norcroas 110° F, (43'3C.) In June 1870 at the 900-foot
level of the Yellow Jacket Mine the temperature was gy'F.{^6-i C.)
at a point only 300 feet from the shaft, although blowers were at
work. The highest temperatures were observed when loag levels
were driven without any ventilating abaf tB or winzes. As soon as
a proper air-current was established the tempeniture usually sank
rapidly. Thus the thermometer stood at 130° to 140° F. (54 to
60° C.) in a drift at the 1850-foot level of the Bullion Mine, but-
when connection was made with another shaft the thermometO'
went down to 100° F. (37"7° C.) The mineni working in the hot
levels were supplied with ice, which was sent down by the ton.
Their average daily consumption in the hottest parts of the
California and Consolidated mines during the siunmer of 187$
was 95 pounds of ice per man, and they would commonly drink
as much as three gallons of water in the shift of eight hours.
It was not only the air of the mine which was hot, the water
was even hotter. The spring in the Savage mine had a tempera-
ture of DO less than 157° F. (694* C), and the incline was filled
with scalding vapour. Uptotheendof 1877 the highest recorded
temperature of the water was 154° F, {677° 0.); but since than aii
increase in the water temperature to 170° F. (76'6°C.) has been
Doted. The Comstock mines are the hottest in the world.
At Dolcoath,t the largest and deepest tin mine in ComwaJl, the
temperature of the water issuing from the rock in the lowest
workingB is nearly 100° F. {377° C.) and that of the air 96' F.
(35-5* 0.) The bottom level is now 2434 feet vertically below the
surface.
In the adjacent Cook's Kitchen mine, which approaches its
neighbour in depth, the air in the end of the 394-fatiiom level, at
no great distance from a winze, will raise the thermometer to
95° -^* (35° ^')i whilst in the ends of the 430-fathom level, driven
out but a very short distance from the bottom of the shaft, the
temperature of the air is 100° F. (377° C.) and that of the water
slightly higher. Some workings for copper at St. Day, Comwall,
were even hotter, but the mine has long been abandoned. The
submarine mines near the Land's End are also warm, and air-
temperatures above 90° F. {32° C.) are often recorded. In Corn-
wall, as in Nevada, the hottest places are "ends" or "rises'
before they are " holed " to other workings. When once a com-
munication has been effected and a through draught established,
the rock-faces cool down quickly.
* Lord, "Comstock Hiniogand Ulnen," Mtmogr<^ht U.S. 0«l.Sirv^,
Washington, 18S3, p. 391 et ttq.
t HS. Infonoation from Hi. W. Thomas, F.O.B., 1893.
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CONDITION OF THE MINER. 671
With the temperaturea just mentioned, it ie evident that the
miner requires vei? little clothing, but even when the air is
comfortably cool, he often strips himself to the waist, in order to
socore that freedom of limb which eo much conducee to the
efficiency of muscular labour.
In some cases, such as in the salt mines of this country',
the working-places are very comfortable; indeed the miner is
better off than the labourer at the surface. He is not exposed to-
the burning sun, cutting winds or torrents of rain ; but he works
in a cool and pleasant atmosphere, varying little in temperature,
and be has not to assume a cramped posture. On the other hand, the
miner's working- place may be moist and steaming, or hot, dry and
dusty, or cold, wet and draughty ; and on reatihing the surface in
a <:age, he may have to face on icy blast after leaving a tropical
atmosphere only a minute or two before. Where circumstances
are so unlike, the clothing worn in the mine must necessarily vary,
to say nothing of differences in attire due to the habits of the people.
The South African native, content with a waist-cloth above
ground, requires nothing more when he descends into the diamond
mines, whUst the white man, true to his bringing up, needs, or
thinks he needs, more abundant vestments.
Hat. — Some of the clothing used below ground has to serve a
different purpose to tbat required of it at the surface. One object
of the miner's hat is to preserve his head from blows, as he walks
along low and rugged tunnels, and from falls of stones while work-
ing in shafts, l^e Comishman wears a hat made of felt and
rosin, shaped like an ordinary " pot hat " of everyday life. It is
cheap and durable, and affords admirable protection against hard
rape ; but it is not ventilated, and it is heavy, weighing about one
pound, or four times as much as an ordinary felt hat. Under it
the Comishman wears a cap of calico or linen, which often con-
stitutes the headgear in the working place itself, whilst the hard
hat is donned in going to and from the surface. A few gimlet
holes improve the Cornish hat, by affording a little vent for
the penpuatioii given off so freely when cUmlung ladders in warm
shafts.
The Cornish hat is serviceable as the brim keeps the neck
dry, and in sinking very wet shafts a waterproof flap can he
added, so as to increase the amount of protection. Lastly,
the lump of clay used as a candle-holder can he easily and
safely stack upon the hat, leaving the miner both hands free
when he is climbing about the workings l^ rope, chain or
ladder.
The British min^, working upon seams of stratified ironstone,
afiecte a leathern cap, which he wean with the small peak turned
towards the back. It is far lighter than the Cornish hat, but it is
not capable of resisting so hard a blow.
In Fnmce a leathern bat, in shape like the Comishman's,
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672 ORE AND STONE-MINIKG.
is oommon. It is made of thick solid leather, and is therefore very
strong and durable, but it is heavy and expensive.
In some parts of Germany the miner wears a brimless hat,
something like a busby, made of loose-textured felt, thick enongh
to prevent a tolerably hard knock from doing any harm, and yet
porous enough to admit the passage of perspiration. In suoleas
workings a brim is not required for guarding the eyes, and In dry
mines the German hat with an undercap of Unen forms averysnit-
able head covering. It is light, weighing only about half a ponnd,
and it can be folded, which is an advantage if one is travelling. On
the other hand, its porosity and its want of a brim render it
unfitted for vety wet places, and it cannot be used for carrying the
candle in the same way as the Cornish hat.
The hat of the Mansfeld copper miner is made of thick black
felt and weighs half a pound ; it has a broad brim which is turned
up in front and covered with leather. A pieoe of wire sewn on
under the leather serves as a hook for carrying the lamp on the
head, though, now that the shafts are mostly provided with cagen,
there is little ladder work to make this necessary. The felt is thick
enough to save the head if struck, and the brim protects the neck
from drops of water. It is a light, comfortable and cheap hat.
In sinking oil wells in Roumania, the miner adopts a conical bat,
shaped like that of the Chinaman, but made of tinplate, which
serves to keep otTthe drops of water and petroleum.
Looking at the number of accidents from falls of roof, to say'
nothing of accidents from things falling down shafts, the natnrs
of the oead-gear adopted by the miner is not without importance.
It is especially necessary that shaft-sinkers should be careful to
have suitable hats. An ideal bat would be light, but strong, well-
ventilated, and with brim enough t« prevent water from runninif
down the neck.
Boota. — Turning to the other extremity of the body, it is fre-
quently noticed that the Cornishman, though careful about bia
head, pays very little attention to his feet. He often has to
walk through wet levels, and knowing that he cannot i-each his
working-place dry-shod, he is quite content with any dilapidated
foot-gear. Unfortunately this carelessness is sometimes the cause
of accidents, for men have been known to slip froin ladders from
wearing shoes which did not give them a proper foothold.
In some of the Welsh ore mines the clog is very commonly
worn ; it is a boot with wooden soles and leather " uppers." Tfae
sole is protected from too rapid wear by irons at the bottom and
sides. Many miners like clogs, as the wooden sole is warmer than
leather, and considerthat they are less likely to slip than ordinary
boots or shoes in climbing up and down ladders or st«ep
" stopes." I can well imagine that the stiff wooden sole
gave a better foothold on tfae vertical ladders of tfae FUnt-
.shire mines years ago than yielding leather. The (^og has tht
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CONDITION OP THE MINER. 673
further merit of cbeapneaa, but the unbending sole renders
it therefore lees comfortable than the ordinary foot-gear for much
'Walking. Men who use clogs below ground often walk to and
from the mines in leathern boots or shoes.
The Feetiniog " rockman," whose working-plaee lies among
smooth surfaces of slate, trusts to a strong laced boot well shod
with nails to prevent his slipping, while he climbs about chain in
hand. Another reason for the strong foot-covering is the fact
that the fragments of rock ore often sharp and cutting.
Many miners in France still wear the clumsy but cheap wooden
shoe or "sabot," whilst in Spain the; have sandals made of
esparto grass. These cost only ^d. or 3^. per pair, and last from
three weeks to a month. Lastly, when we travel further afield,
we find the hardy miner going barefoot, provided by nature alone
with a tough oater tegument, which gives him a better hold on
rock or ladder than any which art can furnish.
Jaokat. — Little need be said about the clothing of the worker
at the surface, save that where he is engaged near machinery
it is advisable that the jacket should fit closely. Accidents have
happened from loose clothing being blown on to revolving gearing
or shafting, which could not be stopped until the unfortunate
workman had been drawn in and mangled.
As has been already explained, it is necessary from time to
time to clean out the Sues in which arsenic has collected from
the calcination of ores containing mispickel. Under the Special
Rules in force at some of the Cornish mines, the owner has to
provide suitable clothing for this work ; probably the best is a
combination suit consisting of jacket and trousers in one garment,
such as is used for going into boilers. The legs of the trousers
should be tied round the ankles, and the sleeves round the wrists,
in order to prevent any particles of arsenic from finding their
way to the skin and so doing mischief.
2. HOUSIITQ. — It may or may not fall to the lot of the
mine-owner to provide dwellings for some or all of his workmen,
but in any case it is his duty to interest himself in the question
of the living accommodation for them and their families. Even
if he is not moved by considerations of a humanitarian nature, as
he certainly ought to be, the mine-owner must recognise the fact
that it does not answer commercially to let his men fall sick, become
prematurely unfit for work or die at an early age ; nor does it pay
to have the working staff constantly changing. A valuable horse
is put into a good stable, is well tended and not overworked,
if the master wishes to derive as much profit as possible from it ;
and it cannot be expected that the best results will be got from
the miner's labour, unless he is treated with at least as much con-
sideration as the lower animal. Therefore on the score of profit
as well as upon the score of humanity, the mine-owner should
insist upon proper dwellings being available for his men.
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674 ORE AND 8T0NE-MINIKG.
Whec mismg is carried on in the midat of a fairly populous
difltrict, private enterprise may often be relied on for providing
suitable cottages, nevertheless even here the mineKtwner may do
good by calling the attention of the local authoritiee to iosaDitaiy
dwellings or cases of overcrowding. It frequently happens,
however, that mines are worked in out-of-the-way places^ wlm«,
ftt all events la the early days of the enterprise, there is a totMl
absence or ntter inadequacy of accommodatioD for t^e workpeople.
The mine-owner is then obliged to take upon fais own shooldera
the burden of providing dwellings. Two clasBes may be erected :
(i) Barracks, which serve fw unmarried men, or for married
men whose homes are not within the reach of a daily walk ;
{3) Cottages for married couples and their children.
Barracks. — Excellent examples of barracks are found, for
instance, at the Alechemich lead and the Uansfeld copper mines,
owned by two enlightened and proeperous companies. The lairge
workmen's hotel at Mechernich is capaUe of accommodating
about 400 men. The workmen are perfectly free to do as they
like, as regards living iu the barracks or not ; but if they do live
there, they must conform to the regulations.
The cost of lodging is gd. per week ; for this a man gets a
comfortable bed with a spring mattress, and clean sheets and
blankets. The beds are such as I would sleep in without hesi-
tation. The space allowed in the bedrooms is 400 cubic feet per
man, and in winter the rooms are warmed by hot air. They
are kept scrupulously clean, and the men are obliged to chan^
their working clothes as soon as they come in, and put on other
suits.
The men can be supplied with their meals at stated hours in
the large dining hall at low prices, and boiling water is always
ready for them gratis, so they can make coffee from their own
store if they like. The dining hall has a tiled floor, and the
tables are scrubbed until they are exquisitely clean.
The sanitary conveniences are ample and well kept, and the
men can have warm shower-baths free of cost.
The mental comforts are not forgotten. There is a reading
room, with newspapers, which is open after working hours, and a
library, from which the men can borrow books.
At the Mansfeld copper mines the company have provided no
less than nine barracks, capable of accommodating 2268 men
and 48 females. The barracks at Eisleben, which w^l house 350
men, are represented in Figs. 700 and 701, taken from the long
and careful report of Oberbei^grath Taeglichsbeck.* The house is
a three-storey brick building, with bedrooms for nine, ten, or eleven
men each. In accordance with official r^ulatioos, there is an air
* " Die WohniuiKareThSltDisBe der Baig- uiid SaliaeDOTbeiter im Ober-
bei^amUbezirke Halle, einscbliesslich der Hanafelder Huttenarbeiter,"
ZaUdtr.f. B- H.-u, S.-WtrKnim Praut. StatUt, voL xl. 1892, p. 44.
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CONDITION OF THE MINER.
Fio, 700.
Front Blevitloii.
Fig. 701.
5 MET RES 0
20 MCTRCS2S
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676 Ore ANi) STONE-MINING.
space of 350 to 400 cubic feet (10 toil cubic metres) per man.
The rooms are heated with hot air in winter, and there is a l&rge
dining-hall adjoining the kitchen, in a separate building, connected
with the dormitories by a covered way. Thin building ooet
^937°) including a house for the steward, who superintends
everything, and laying on water. The bamtcks are built in
airy aituatione, and are mostly surrounded by gardens. They^ are
provided with all sorts of conveniences, l»ths, reading-rooms,
libraries, skittle-alleys, Jcc.
The men lodging at the barracks pay the fixed tariff of gd. per
day for their board ; for breakfast each man gets ^ litre of coffee
and milk; for dinner 11 litre (2 pints) of thick soup or vege-
tables, with J kil. (4^ ozs.) of beef or pork, weighed after cooking
and without bone ; and for supper ij litres (3 pints) of thick
soup, made with suet, or coffee and milk. In addition te this, he
receives weekly two loaves of bread, each weighing 3 kil. (6*6 lbs.),
^ kil. (^ lb.) of butter, and the same amount of fat. Those who
prefer it can take ham, sausage, or bacon instead of the butter
and fat. For lodgings, hghts, and firing, each boarder has to pay
o'6d. {5 pf.) per day in summer and ogd, (S pf.) per day in winter.
Order and cleanliness are enforced by a code of regulations,
which have to be strictly obeerved by all the boarders. The
rules prescribed for the barracks at Mansfeld, Staasfurt, &c., are
given at length by Taeglichsbeck.*
The barrack system is also found in this country, especially in
North Wales, but not on bo large or so sumptuous a scale as in
Germany. In Wales the men often sleep two in a bed, upon stntw
mattresses; and, as a rule, there is not a separate eating-room, nor
are there any arrangements for supplying meals. One sees the
men arrive on a Monday morning, carrying their provisions for
the week on their backs ; and they cook their food themselves by
the common fire of the eating and sleeping apartment. Often
there is no person provided for keeping the rooms clean, and the
disorder and discomfort are consequently great. Sheer ignonmce
is sometimes the cause of some of the evils. I have seen bunks
prepared for 2 1 men in a room without a window or a chimney,
and containing only 2ioo cubic feet of space — i.e., about one-third
of the smallest amount which sanitarians would consider requisite.
If mining companies build barracks, they should employ some one
aoquMDted with the rudimente of sanitary science to design them ;
the eating-room should be separate from the dormitories, and the
house should be kept clean and tidy.
The most extensive development of the barrack system in any
British possessions is at the Eimberley diamond mines, where
the particular exigencies of the case have led to a modification
which is not found elsewhere. One great difiiculty of diamond
• Vp.cii. p. no.
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CONDITION OF THE MINEE. 677
fnin'"g in the early days was the prevention of thefte of valuaUe
stones. Qema of great value can be so easily secreted about the
person, or indeed awallowed, that the mine owner could be, and
was, robbed with little fear of detection. It is true that since the
passing of the Illicit Diamond Act, the disposal of stolen diamonds
has become more difficult, but the protection afforded by this
statute does not entirely suffice. The plan now adopted with the
native miners is to confine them for the length of their contract,
often three months, and not allow them on any pretext to leave
the company's premises. They go straight from their barracks
to the mine by a securely enclosed way, and return to them as soon
as work is over. The barracks consist of one-storey buildincs, made
of corrugated iron, arranged so as to form the four sides of a
large square, and divided into rooms holding about twenty natives
each. The "compound,"* as it is called, often covers several
acres ; and it is surrounded hy a high iron fence i o feet from the
building. The natives can procure all the neceesaries of life from
a store within the compound, whilst food and water are supplied
free. A large swimming bath enables them to enjoy a dip when-
ever they tike. If perchance a man falls ill, he is taken to a
hospital, also belonging to the company.
Of course, this system would not find favour with European
miners, who would resent the enforced confinement and regard it
as on irksome imprisonment ; but the native, with fewer wants,
is quite content t<3 put up with the temporary loss of liberty for
the sake of getting good wages.
Cottages. — Enough has been said about berrHcks, and we may
now pass on to cottages for families. At many of the collieries
of this and other countries, great attention has been paid to the
erection of workmen's villt^es, and a large amount of capital has
been sunk in providing comfortable and convenient dwellings.
It is an advantage to the mine-owner to have his men on the
spot, coming to their work without the fatigue of a long walk ;
and it is a benefit to the man to have his home within easy reach.
When, therefore, the preliminary explorations and workings have
revealed the existence of enough mineral to supply a mine for a
number of years, a company is thoroughly justified in spending
money upon houses.
Figures 702 to 705 represent the tjrpe of miner's cottage lately
erected by Mr. Emerson Bainbridge for the Bolsover Collieries in
ITottinghamahire. It will be seen that each cottage has a good
living-room and scullery on the ground floor, two good bedrooms
on the first floor, and an attic above.
Many a workman, however, would rather be his own landl<»xl,
and not feel the restraint of living in a cottage belonging to the
company, because he may have to quit it if he goes to work at
• iktond Annual Seport oftke Dc Btert CotuoHdattd Mine*, Lmittd.for
the i/ear tndtd March iS9(^ p. 33.
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678
ORE AKD STONE-MINING.
another mine, or because he feete the nstunJ ambition of wishing
to own a bouse himself. In order to encourage this very laadnble
object, mining companies often moke it easy for the workuuui to
buy his cottage by small instalments, and they thus gather aroond
their minee a number of small householders, who are less likely
to encourage disturbances than men who have no special interest
in the preeerratioa of order. To the workman there are advantaf^
Fig, 70a.
FIO. 703.
1
B
1 11 B| 1
as well as disadvantages; if the cottage belongs to him, he has a
feeling of independence, and he does not mind spending mon^ to
embellish or improve it, which he would not do if it were the pro-
perty of somebody else. The purchsse may be a wise and profitable
one, if he feels pretty sure that he is going to spend all his days in
one place ; but this fixedness to one district cannot always be
assured or advised. Wages may be better in an adjoining county
or in some foreign land, mining may decline at home or entirely
cease, and a move may become & necessity, wiUi no chance (Mf
selling the cottage property. Under such circumstances the
earnings spent in buying a cottage will have been badly invested.
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CONDITION OF THE MINER.
679
It also happens that during a period of high wages, a man is
tempted to arrange for the purchase of his house with one of the
numerous building societies, and he agrees, for instance, to pay
£1 per month for ten years, at the end of that time becoming
the owner of a house worth ;^i3o. If his wage^ are jQ"} a
month he can manage the monthly instalments without difficulty ;
hut let wages drop to £^, and he will find it far lees easy to keep
up his payments.
As an example of the manner in which workpeople are housed,
I will again extract some figures from Taeglichsbeck's report."
For the Halle district he gives the following numbers and pro-
portions:
—
Ui« Tottl Komba or Pnwni.
B«itlM,|
bntBnt LMi^ln
rwk«Md{th<lra-n
LiTlng In
bJI^I
Workmen.
Private wotka (40.37a person*)
PriTate works (1196 personi)
GoTemment works (122 penous) .
o!3%i!.Si%
0-36% 27-91%
4S«!% \ l>!S%
73-77% j 9-S4%
701.%
71 14%
3&9S%
16-35%
I'il
He further shows that 25 per cent, of the persons employed at
the Mansfeld copper mines are living in their own houses, of which
nearly one quarter have been pnrclutsed with the asBistance of the
Company.
Before concluding this subject of housing, a word may be said
about the " dries," or changing houses, which have to be provided
at mines under the MetaDiferous Act, when more than twelve
persons are employed below ground. Such a house is very
necessaiy when the men come up wet and dirty, and often soaked
with perspiration frton working in hot places or from climlnnff
long runs di ladders. They then change all their dothee, and
leave them to be dried ready for use on the following day. One
of the best modes of heating a "dry" is by steam ; the shell of
an old boiler is placed along the centre of the house and is supplied
with steam from any convenient source. Owing to the laige
surface of the shell the room b speedily heated, and the dothea
hung about it are quickly dried. Tlie water condensing from
the steam may be drawn off by a cock and used for washing
purposes. Figs. 706 and 707 represent the changing house erected
at Levant Mine in Cornwall bjr Mr. Eustice, which has the
advantage of being put into communication with the man-engine
shaft by a passage and staircase, so that the men stand no risk of
■ Op. eit. p. 7.
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OBE AND STONE-MIHIHa.
I
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CONDITION OF THE MINER. 68i
exposure to the fierce breezes coming iitraight off the Atlantic,
which might sometimes be trying after the undergrounil warmth.
It is heated by rows of hot-water pipes.
The floor of the " dry " should be made of cement and not of
boards, to permit the application of the hose, for washing it.
Benches and lockers should be removable in order to facilitate
the cleaning, which is frequently necessary, considering the
amount of dirt which cannot ftul to accumulate in such a
place. A wooden floor has the disadvantage that the boards are
sure to shrink under the constant warmth, and when once full of
Fio. 708,
gaping chinks it can never be effectnall; cleaned ; besides, there
is the danger from fire, either from matches left carelessly about
or from the men smoking in a place where the wood gets as dry
as tinder. The walls should be whitewashed at regular and
frequent intervals, in order to keep the place thoroughly sweet.
It is not di£Scult to give the miner the luxury of a shower-
bath at a small cost, and it seems to me far better that the miner
should change and perform all necessary ablutions at the mine,
than go home in his imderground clothes, and depend upon the
resources of his cottage for washing himself and drying hb working
apparel.
At the Anzin collieries, in the Norl^li of France, a large number
of shower-baths (E^g. 708), are provided at the different shafts, ih>
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683 ORE AND STONE-MININO.
tbat the men have not to wait for their tnm. The Amin armngt-
meute are excelleat, and might be copied with advantage at
3. EDU'CATIOIT. — The school education may be of tvo
kinds, g;eneral and technical. In this and other oountrieB, when-
the primary education is free, the mine-owner need not ccMiceni
himself with providing schools and teachers; but where the Stat^
does not take this paternal care of the rising generation, a oertaiii
refponeibility for the young b often felt bj the shareholders cf
the mining companiee, and they endeavour to equip the children
of their workmen, at all eventa, with the three R's.
For carrying on mining, it is not sufficient merely to providi'
strong bones and well-developed mnaclee ; there muet also be
brains, or, in other words, no matter how good the miners arr,
their work must be directed by trained engineers and competent
foremen. The latter may well be recruited from among the actual
working men, who should have some general knowledge of adena
and some special training in the various branches of their pro-
fession.
This scientific and technical training is frequently provided bj
the lai^e foreign mining companies at their own ezpenae. The
best of the young men attend claasse out of working hoara, aud
thus manage to carry on their leotnre-room teaching hand in
hand with the practical instruction which they are acquiring in the
mine itself.
In this country the education of the young miner is largely
aided by classes held in the evenings, under the auspices of the
Science and Art Department, the City and Guilds of London
Institute, and some of the County Counrils. The energetic and
ambitious workman can nowadays obtain instruction in mathe-
matics, mechanics, chemistry, physics, geology, the printsples of
mining, ore-dreesing, assaying and mine-surveying in any large
town and often in outlying villages. To those preparing to pas
the ATaiiiiTiii.i-.inTi for a certificate under the Coal Mmes Act, these
classes are very valuable.
The success of local schools and classes depends a good deal
upon the attitude assumed by the managers of mines in the
neighbourhood. If educational work is pooh-poohed by the
masters, the men follow suit and the teaching languishes. On
the other hand, if the headpiece of the sdiool is one of the chief
mining engineers of the district, pupils flock to the lecture-rooms
and laboratories, and success is almost a certainty. By forming
and encouraging these local schools or classes, owners and
managers of mines are not only promoting the welfare of the
rising generation around them, but tbey are at the same time
doin^ good to mining generally, and are contributing to the intro-
duction of the most improved methods of extracting minerals.
Just as the success of an army depends largely upon its trained
.vGooglf
CONDITION OF THE MINER. 683
non-commisBioned ofScere, bo the prosperity of a mining enter-
prise is lai^ely influenced by the competency of the foremen ;
many of them by virtue of their talent and industry rise from
the ranks and become excellent managers of mines.
The training <^ foremen must not be carried on to the exclusion
of all thought for their sisters, who will make better wives and
mothers if they receive some instruction in the arts which belong
more particularly to the domain of women, euoh as housekeeping,
cookery and nursing. Teaching of this kind becomes more than
ever necessary in localities where females are largely employed on
the dressing floors, for then the girls fail to receive that practical
training in household work, which would otherwise fall to thdr
lot, if they entered domestic service, or assisted their motbere in
their own homes.
4. SICKXTESS. — At first sight it might be supposed that
mining is necessarily on unhealthy occupation, that confined
for hours in dark and gloomy passages a man cannot keep well
and strong. Stubborn facts and figures show that a general asser-
t^ion of this kind is not well-founded; but nevertheless the miner
does suffer in some cases from diseases inherent to his calling,
and Uiese can be best combated if their causes are thoroughly
understood by all who are connect«d with mining operations.
The diseases to which miners are most liable have been care-
fully studied by Dr. Ogle,* who with infinite pains has worked
out the death-rates for mining, as well an for other occnpations,
from the figures contained in the national register of deaths.
Of course it is very difficult, if not impossible, in comparing the
death-rate of the miner with that of some other working man,
to say precisely how much of the difference is due to the efiect of
the calling. The miner is to a certain extent a picked man ; the
weaklings of a family do not go to work underground, conse-
quently in the race of life the miner has, so to say, a start, which
ought ceUrig parilma to make him a winner. The actual death'
rates of some occupations are given in the table on p. 684,
extracted from Dr. Ogle's much more complete list. The com-
parative mortality figure aflbrds the easiest means of contrasting
the di£ferences between the various callings as regards healthiness.
The figure 1000 represents the total number of deaths among a
certain number of male persons between the ages of 25 and 65
for the whole of England ; then taking the same number of
persons in any particular calling at the same ages. Dr. Ogle
has calculated the corresponding number of deaths. The lower
the figure, the healthier the occupation. In very healthy dis-
tricts the mortality figure is as low as 804, that ai the agricul-
tural labourers is only 701. If we take miners, we do not tind
a high mortality figure for the collier, nor for the ironstone
.vGoo»^If
684 ORE AND STONE-HININO.
miner; but the figure for Cornwall ib ai^ling. Mining coal
and ironatoue appears to be leas bbtl to life tlian baking brud or
making boots and sboea.
Occvrtnow.
MMa Anrnul DeUb-nta p«
h
Hi
a
l»6o-l-lS7'-
..^.^
TonofAcc
Twntfi«t.
TMHOr
if.
..«.
4s-es-
•5-4S-
4J-«S-
»s-«s-
AUmalM . . . .
MalM in Hlectod bealtby 1
districU 1 ■
I 1-37
83^98
I0-I6
8-47
35-27
«974
1000
804
Baker
Buildar, muoD, bricklarer .
Butcher ....
Sr„ : : : :
Mlnw, ooal . . . .
„ CorawaU .
Labourer, ■jtricultural .
Plumber, painter, glazier .
Quarrier, stone and slate
TaUor
107a
10-07
11-43
1319
.?;s
11-94
1=^
10-8S
i*-92
10-39
4173
2479
13-30
8-70
929
9a7
8-os
14-77
7-13
1I-07
9-9S
10-73
9 '31
36-12
2174
19-74
'Ai\
3249
3'"o4
9S8
973
994
969
1170
830
g!
Z
701
I302
losi
921
The difleaaeB inherent to the miner's calling are due to the
following causes :
Of these various causes the first is undoubtedly hy far the worst :
it brings on phthisis and other diseases of the respiratory organs.
There is nearly six times as great a mortality from these diseaaes
among Cornish miners as there is among fishermen. The
manner in which the air of mines is polluted has been explained
in the chapter upon Ventilation — vie., by the bi-eathing of the men
and animals in the pit, the combustion of lamps or caudles, exhala-
tions of decaying timber, smoke of exploaives, natural emanations
.V Google
CONDITION OF THE MINER. 685
of gases, and dust. It is the opinion of the best qualified judges
that dust is largely responsible for the reepiratoiy ailments from
ivhich the miner so often suffers. The difference between the
atmosphere of a mine and that of the external atmosphere is often
made very plain by the state of the nostrils after a few hours
spent in underground workings ; it is found that they have
strained off a part of the solid particles floating about in the air
of the mine, and the amount so arrested will serve aa some gauge
of the quantity inhaled. Besides, men commonly breathe a great
deal through the mouth, and lose the benefit of their natur^
air- filter.
The dust acts mainly mechanically, but in a few exceptional
cases its evil effects are due also to poisonous chemical properties.
The mechanical action is at first an irritation of the delicate lining
membrane, and then the particles make their way into the tissues,
choke them and harden them, and so render them unfit for,
allowing the chemical action of the air upon the impure venous
blood which is necessary to life. The diseases caused by the
inhalation of dust in this way are bronchitis, shortness of breath,
asthma and consumption.
A large proportion of the dust is produced in the process of
boring holes for blasting in an upward direction. If the hole has
a downward inclination the miner puts water in, which not only
prevents any dust, but also renders his work easier by allowing the
edge of the toot to act more fairly against the rock. "When, on the
other hand, the miner is boring upwards, the dust is ecraped out
or falls out, and though the coarsest portioles may at once drop to
the ground, the very fine and light ones float about, and produce a
cloudy and noaioua atmosphere. If machine drills are employed,
the amount of dust produced in a given time is often considerable,
as will be instantly recognised by any one dressed in a dark suit
who stands by one of UieGS machines while it is working in dry
ground.
Prevention is bett«r than cure, and the evil consequences can be
averted by forcing a jet of water into the hole during the boring
operations. The jet may be produced either by allowing the com-
pressed air to act upon the surface of a tank containing water, or
by bringing down a supply in a pipe from a tank situated at a
higher level ; keeping the sides of the level moist is another
precaution, tiie particles of dust wafted against the wet sur-
face are caught, like flies upon sticky paper, and so rraidered
harmless.
Some of the dust arises from the rock being broken up in the
process of blasting, and some comes from the explosive itself,
if it consists, for insUnce, of infusorial earth mixed with nitro-
glycerine.
A fine spray is very effective in laying the dust and fumes pro-
duced by blasting, and an easy method of producing it is to
.vGoo»^If
686 ORE AND STONE- MINING.
turn a jet of compresBed air into a pipe aupplied wiUi mt^.*
An appli&nce of this kind in Bpeci&llj deairable 'when the Uasi-
ing ia an "end" is done by voUeyB, when the miner has to wslk
into the smoke of one blast in (wder to charge axiother sec o:
holes. Some men make use of a sponge as a respirator whilr
exposed to the dust and fumes, aod no doubt with good eflects :
but it is well to delay the return as long as possible, uolesa the
" end " is provided with such an apparatus as Teague's ventilator,
which speedily withdraws all noxious fumes from the 'workia^
place. If it is necessary in some particular case to go into as
" end " full of smoke, the harmful etFects may be reduced bv
making use of Nature's respirator, namely, the nose, and not
breathing at all through the mouth.
Dusts which have a poisonous effect are thoee of certain minei«]$
containing arsenic, lead and mercury.
Aooorduig to Dr. Hiiiting and Dr. Heese.t cancer in the luaga
is not uncommon among the men woridng in the cobalt mines of
Schneeberg in Saxony, and they ascribe the disease to dost
c(»taining arsenic in combination with cobalt, which produces a
permanent chemical irritation in the delicate air-passages. It seems
to be mainly the mineral speiscobalt or smaltite (GoAs,) irhich is
the source of the disease, the cobalt minerals containing sulpbor
in addition to the arsenic are far less poisonous, as they »re lees
readily decomposed. When one reflects how soon cobalt bloom,
the hydrated arseniate of the metal, is formed upon the ores in a
damp atmosphere, it is not surprising that a eamilar action should
go on with minute particles of smaltite imbedded in the long
tissue, and eventually set up a considerable amount of irritation.
Far more dangerous than the dust of arsenical minerals under-
ground, are the fumes produced in roasting ores containing mLs-
pickel, a process which goes on in many tin mines and some gold and
copper mines. Particles of arsenious acid attach themselves to the
sInn, in places where it is moist from perspiration, and produce
nasty sores, whilst those which enter the body give rise to variouit
disturbances of the digestive organs. The best means of avoiding
the ills due to arsenic have been pointed out by Hirt t at some
length. Only thoroughly healthy men should be allowed to work
in places where there is danger from arsenic, and they should be
relieved at regular intervals. Bottles of hydrated oside of iron,
in the form of an emulsion should be kept in readiness, both as a
preventative and an antidote. The men must be compelled to
exercise the greatest cleanliness, and when exposed to the dust and
vapours should cover the mouth with a dry cloth. Arsenical 8ore$
• Report* of H.ii. Intpeclort of Mtnet for the Tear 1879, p. 527.
\ " Der Lnngenbiebfl, die Bergkiaokheit in deo Schneebe^ar Graben."
Etdeniierg't Vitrtiljahrtieltrift far gtriehtliche Mtdtcin. Neue Folge, in.
BADd, p. 196, Berlin, 1879.
X Arbeiter-Schviz., Leipeic, 1S79, p. 131,
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CONDITION OF THE MINER. 687
Bhould be plastered over with fuller's earth moistened with water
and hydrated oxide of iron ; strong drinks, especially hrandy,
must be avoided, but milk and greasy soups h(^p to reaiBt the
poison.
In an ordinary lead mine, where the ore coneistB entirely or
almost entirely of galena, plumbiam is rarely heard of; but
when the ore is cemssite, a different state of things arises
and the disease may be rife. It ia well known that the arti-
ficial carbonate, the white lead of commerce, produces poisoning
among painteis, so much so indeed that one of the ailments due
to lead is known bb " painters' colic ; " it cannot therefore surprise
us, when mere handling ia injurious, that breathing a lead-laden
atmosphere should hkewise be pernicious. Flumbism among
miners has probably never been so prevalent as in the Broken
Hill district in New South Wales, where some of the ore iu tbe
shallow levels isapulverulentearthy carbonate of lead. According to
published aocounte,* the state of things must have been very bad in-
deed comparatively lately. Miners sufiered more tbon the smelters,
but even the ore-pickers were not exempt from the malady. From
this fact we may conclude that lead may have entered tbe system
in some cases by eating food with dirty fingers, or, as suggested by
the writer of the article alluded to, from smoking a pipe filled with
tobacco rubbed i& a leady hand. Tbe baneful effects have been
reduced by not allowing the men to work very long at one time
in tbe parts of tbe mine where the soft carbonato occurs. The
managers arrange, for instance, that a man shall take one fort-
night at mining the earthy cerussite ; the next fortnight he is put
to work at tbe surface and made to quarry the ironstone — i.e., the
ferruginous outcrop of gossan, which is used as a flux at the
smelting works ; and then he takes a fortnight underground
in mining the kaolin ore, which consists largeJy of kaolin and
chloride of silver, and has no deleterious effect upon the men, or
at all events does not cause lead-poisoning.
The precautions to be adopted against plumbism at mines of
this description are : ample ventilation, laying the dust as for
as possible by a spray of water, and the strictest cleanliness. The
mine-owner should do his share by giving the men every possible
convenience for washing themselves and changing their working
clothes, but no amount of forethought on his part will suffice to
prevent the evil entirely, if the men fail to avoid eveiy chance of
defiling their food or tobacco by lead ore.
Working iu the quicksilver mines is found to be unhealthy,
and the men suffer from mercurial poisoning unless special
precautions are taken. Thus, at Almaden, even if tbe ventilation
is good, the miner cannot work more than four to four and a half
hours a day, nor can he work more than seven or eight days in a
1891,
.vGooglf
688 ORE AND 8TONE-MII7IKG.
month witliout injuring bis health very rapidly.* It Is true tlisi
the mitms suffer Imb than the Bmelters, which is the neTsree at
what happens at Broken Hill, and the explanation of this is thu
mercurial poifioning is mainly due to the vapour of the metaL At
Almaden some of the mercury exists in the native state aztd i^
supposed to sublime slowlj ; t but even at Idria, irhere iitert i'
no native mercuiy, where the ore is lees rich than at Almaden,
and the ventilation excellent, the men work only fonr honn ax t
stretch — i.e., four hours in the morning and four in the af tecnocE.
with an interval of reet of four hours.
The Hymptoma of mercurial pdsouing noticed at Alnuulen are :
inflammation of the mouth, salivation and loss of teetb, shivn
ings, gradual and general wasting away.
Excessive ladder-climbing has long been pointed out hy medial
men as a cause of disease.^ If the heart is over-stretched daj
after day and year after year, it becomes dilated, loses some of
its contractile power, and is therefore less c^xtble of performing;
its pumping action properly. The miner who for yectrs bas h&d
to descend and ascend by ladders in deep mines, will generallj
be found to have a feeble heart and weak pulse on this aooount
Young miners should be careful to avoid the over-exertion caused br
climbing with unnecessary haste. In these days of excellent steci
wire ropes for winding men up in cages, it is perfectly absurd
that a miner should be condemned to the treadmill toil of ladder-
climbing, whicb has nothing to be utged in its favour. Hie
shareholder has to pay for an unprofitable form of laboor, bis
mine is conducted with lees supervision than there wvnld be if
access to the workings were easier, whilst the unfortunate miner
suffers in health and strength. When a mine reaches a depth of
loo yards the owner should introduce means of raising and lower-
ing the men mechanically without fatigue.
It is easy to conceive, when a man is working continnouslr
for years in a constrained position, that certain muscles will be
stunted in their growth from want of use, and that others -will be
abnormally enlarged from over-use, and so cause a distortion of
the body. This happens to a sUgbt extent with the men wtx-king
on the thiu bed of copper shale of Mansfeld.
The disease of the eye known as nystagmus has been noticed
among colliers. A person suffering from nystagmus sees objects
apparently moving in a circle ; gas lights in a room, for instance,
seem to dance ; the man also suffers from headache and giddinase.
* Kuss. " Note Bar I'dtat aotuBl de la mine et de I'liaii
Annalei da Mina, 8me. B^rls, tome xi., p. 138.
+ Eag. Mia. Jour., vol, iW,, 1888, p. 435.
I Dr Peacock, " Medical Report on the Condition of Hlnen " ; Banfaul.
"Medical Report on the Condition of Hlnere in Cornwall and Deron" ;
Apptndij: B. to the Report of the CnrnmUiitmeri appointed to Jn^Nwv mIo Ue
(^nditioa of all Miaet in Oreat Britain to vjhieh the IV^ioitiom of (te Act
33 & 24 Vict. cap. 151 do nof ofiply. P. J and p. 95, London, 1864.
, Google
CONDITION OF THE MINER. 689
and the eyeballs are noticed to oscillate or rotate. According
to Bnell * the men most afflicted with nystagmus are those who
have to work lying on their side ; owing to this unnatural
podtion the muscles of the eyes are unduly strained and suffer
from overwork. Uere work upon the side is in some districts
insufficient to set up the disease, for during a period of six years
only two caaee were noticed among the 14,000 Mausfeld copper
minera As these men use open lighte, it is not unnatural that
nystagmus should have been ascribed by some doctors to the
insufflcient illumination afforded by the safety lamp. Snell
combats this hypothesis, and dtes cases of the disease in persons
who have never used a safety lamp ; therefore the want of a
bettor light cannot be the only cause. To a layman it seems
quite possible that both views may be correct; the two sets of
doctors agree that the disease is produced by over-etmin of the
ocular muscles, and as either of the two causes appears capable
of occasioning such a strain, why should there be a difficulty in
admitting both explanations ?
The great heat of the workings on the Comstockf lode has
been mentioned in the early part of this chapter, and many men
are said to have lost their lives from it, being picked up dead
in the mine. New-comers sofiered more th^ the old hands.
There was also the danger of falling into scalding water; men
fell accidentally into pools of water at a temperature of 157° or
1 53° and perished in great suffering from their skin peeling off.
In some cases the effect of the hot air on the men is said to
have been beneficial, acting like a succession of Turkish baths.
When the heat on the Comstock lode first became intense, the
miners suffered from pneumonia and rheumatism, becauee they
went out at once into the cold and freezing atmosphere at the
top of the shaft, although only a few minutes before they had
been in the heated atmosphere of the lower levels. Such sudden
changes of temperature were naturally injurious; and experience
soon taught the men and the managers that risks of this kind
could not be run with impunity. Good rooms were erected at
the tops of the shafts, in which the men could change their
clothes, and some were provided with baths. These precautions
soon brought about an improvement in the general h^th of the
men.
In ordinary mimng operations, men are rarely subjected to a
pressure considerably above that of the surrounding atmosphere ;
but as work in compressed air is occasionally necessary, it is
well that the student should he reminded of its danger to health.
Men who are employed in making foundations for bridges or in
driving tunnels, where compressed air is used as a means of
* MintTi' Nyttagnaa, Briitol, 1892.
t Loid, " Comstock Hinlng and UlDers." Monographa U.S. Otol, Surrey,
vol. It., WuhingtoD, 1883, pp. 374 to 399.
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Ogo ORE AND STONE-MINING.
keeping oat water, suffer at ticoee from paralyds and intoa
pain in the back. These effects of the confinement eeem to be
muolf felt on imniiag ont into a less dense atmosphere, and mij be
lessened by prolonging the stay in the air-lock, and so caosiiig tbe
diminution of pressure to be felt gradually.
5. THRIFT. — Remarks upon the condition of the iciiei
would be incomplete without some mention of the follo«ui;
subjects: — (i) ProTiaion against loss of pay from sickness uti-
dents, strikes, and old ag« ; (2) Obtaining medical atteodaacr n
a small cost; (3) Procuring supplies of food and doChing npoi
the most reasonable terms.
Frovident societies are no new thing for the miner ; it hts been
pointed out 1^ Dr. Wahle, the Director of the Mining Dcput-
ment at IVeiberg, that they date back in Saxony to tk
fifteenth century, and are as old as mining itself. In l&
country at the present day three systems are in vogue: cinl^
for individual mines, general relief societies for large distncU
and, lastly, the ordinary friendly societies, not confined to dudhs,
which are resorted to by all classes of workmen.
In Oomwall and Devon, and in many parts of Wales, then m
a dub for each mine, and the men agree to a deduction beiu
made from their wagee every month for " doctor and dab." At
many mines the monthly deduction for the doctor is either sii-
pence, or one shilling, according as he attends the miner onlv, "
bis family also.* Under the pronsioDs of the Stannariw M
1887, some of the old grievances of the Comishmen have bets
made to disappear. fUcb man has a right to choose his on
doctor, to whom the amount deducted from his ^ragee is ptii
If a surgeon renders himself unpopular by not attending u>
case with sufficient care, the men do not select him another time,
and his pay and reputation suffer. This check upon the doctm
seems to be a su£Sdeut guarantee of the system working smoothlr.
and to the satisfaction of those most interested in the matter— vii-
the men themselves.
The usual deduction for " dub " is 6d., and in a few cases 9^
per man per month; the usual "hurt pay" for disablemesl i:
IS. per day. In the event of a fatal acddent the funeral ezpesK
are borne by the mine, and sometimes the sum of ^10 is gives to
the widow or dependent relatives, or a levy of is. per mwi "s
made for their boiefit.
The great faults of this system are : Fint, the want of ecm
provision for widows, orphans, or dependent relatives of penof
killed by acddents ; secondly, the fact that a man loses his " b^
pay " and is probably thrown on the parish if the mine in
which he had been working is stopped ; thirdly, the want d ui(
* Fotter and Fike, " Sag^eatlons for the Forniation of a IDiian' F"'
tnauent Clnb and Ballsf 8ociet7 for Oomwall and Devon," JVo& JfU. M
.V Google
CONDITION OF THE MINER. 691
provision for ordinary sicknesB. Of course thn first aod third
objections might be removed hj iocreaaing the monthly aubscrip-
tions, bat the second would still remain — viz., the uncertainty of
the benefits being kept up permanently.
Far better th&n the clubs of individual mines are the perma-
nent relief societies, of which British miners have reason to be
proud. There are now nine of these societies in different parts
of England and Wales, and there is also a central society for
promoting and watching over their interests and extending their
work to new districts.*
Though started for colliers, these societies include many iron-
stone miners and some lead miners and slate quarriera among
their members. Acccsiling to the annual report of the Asso-
ciation for i89[, there were 268,971 persons members of
these relief societies in the yeai- 1890, whilst the total number
omployed in and about the mines of the United Kingdom was
^74)434i inclusive of those employed on private branch railways
and tramways, and in washing and coking coal on premises adja-
cent to or belonging to the mine.
The exact nature of one of these societies will be best appre-
ciated by examining the rules of the largest, which has done,
and is still doing, much excellent work in the North of England.!
As it includes the Cleveland ironstone district, although this
does not appear from the title, it is specially adapted for my
purpose. Its objects are very clearly defined thus :
" The objects of this Society are the raising of funds by volun-
tary subscriptions amongst the members thereof, and by donations
from others to make provision in case of fatal and non-fatal
accidente as follows :
" (a) A sum at the death ol a member.
" ji] A weekly allowuiiie to the widow and children of married
msmberi.
" (r) A weekly sllowanoe to member* who inffer from non-fatal
aocidentB.
" (d) An allowance to the parent, or siater, or brother of a deceaaed
member dnring BicknesB or other InOrmity.
" (e) AI«o to miUie a prOTision for minera over 60 years of age who are
permanently nnflt to work, the allowanoe to be paid to be in
accordance with the contribations received.''
The weekly contribution of each member is 4c!., and of a half-
member — i.e., a boy under 18 1 only 2d. Three-eighths of these
sums are devoted to the superannuation fund.
* Cential Assooiatloii for Dealing; with Distress caused by Mining
Acoidenta, 31A, Hing Street, Wigan ; Qeorge L. Campbell, Secretary.
+ Rales of the Noithomberland and Dorbam Miners' Permanent Relief
Fund Friendly Society. Established Jnne 7, 186a. Chief OfSoe—
S, Qaeen'e Square, Newoastle-npon-Tyne. 1892.
t A boy nnder 18 bnt over 16 may be a whole member if he likes ; a
Iwy under 16 can only be a half member.
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692 ORE AKD STONE MINING.
Tlie bensfits an in the ewe of
1. KoD-fatol Moidenia.
3. FMaI accidents.
3. Oldage.
If ft member is diaabled by ux accideot for more than > <ne^
but not leas, he receives the Bum of 5», & weak or iod. per will-
ing day, and a half -member zs. 6d. per week or 51^. per itj. Tit
paymenta go on in this way for twenty-eir weeks, wbrai, if li--^
person is still disabled, he becomes entitled to the higher ret:
of 8«. per week, or 4s. if he is a half-member, so long u i» -■
nnable to work from the e£Eecta of the aoddent.
In tiie oaae of a death )^ accidmtt, the widow of & miniH
membw reccdvee a legacy of ^5, the relatives of an immiiiii^
member receive £2^, and those of a half-member ;^ii. ^^
widow also draws 51, a week from the funds for the rest ot te
life, eo long as she remains unmarned, and aa. a week tot m
child, ontil the boys are thirteen and the girls fourteen tur -i
age.
Aged and infirm memberu over sixty years of age who v^
certified medicaUy to be unfit to follow their employm^t n(*3'~
41. per week ; but the amount of the pension may he reduced :
the fimda at any time are insufficient to keep up the po*'^'
allowance.
Daring the year 1891 this Society had 113,134 members;!'^
contributdonsof the members amounted to ^£90,169, those of U-
owners of collieries to ^£'4860, tn addition to which there ^^
income of ^^5208 from invested funds. The followmg (to"
were made upon the Society :
Minor Accidentt. — 16,500 claims for relief were made; tlf
average length of the period of disablement was about ji v^'
each.
Permanent Ditablmumt. — 195 claims for accidents that !««
caused disablement lasting more tban 36 weeks; the aTcnf
duration of each is estimated to be 3^ years.
I'atal AccideTUs. — 93 widows came on to the funds.
Children. — 185 children came on to the funds.
Old Age. — 442 new claims for superannuation were made.
According to the report of the Central Association* the nm'
societies gave relief for 754 deaths by accidents, and for 39i4"
cases of disablement during the year 1890.
We learn from the Reports of Inspectors of Mines that thff'
were t3o6 deaths from aocidentit at all the mines of the Uiu''''
Kingdom in that year, consequently it is evident that a large ^
portion of the victims of these fatalities were insured, and tW'
* Central Araociatioti for Dealing with Distress Caused b; Hinixs'f^
dents. Report of the Protetdingt at the Twelfth Anmtal Oonfertiiei, 1'^"°^
1891, Tables VL and VII., pp. 36-7.
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CONDITION OF THE MIXER. 693
their familiea or dependent relatives received some form of
relief.
Altogetherther6were239S widowsand 3496 chfldren receiving
benefits from the ftmda of the niuo societira in the year 1890.
The percentage proportion of the eontributiond of the colliery
owners to those of the ordinary memben is less in the KoTthumbw-
land and Durham Society than in the others. la 1890 it repre-
sented only 5-7 per cent.,* whilst in the Lancashire and Cheshire
Society it was 24*1 per cent., in the North Wales Society 25*2 per
cent., and in the Monmouthahire and South Wales Society 24 per
cent. If we turn to Table IX. of the report, the reason of this
difference becomes apparent ; it will be seen that all, or a veiy
large number, of the members of these three societies have
entered into an agreement with the owners not to bring any
claim against them under the Employers' Liability Act of 1880,
or, to use the common expression, they have " contracted them-
selves out of the Act." They consider that the employer's con-
tribution ui worth more to them than the chance of occasionally
obtaining compensation by [noving negligence against him in a
court of law.
Enough has been said to show the present state of the volun-
taiy system of relief as it now exists in England and Wales ;
much of the distress cansed by mining aoddents is relieved by the
nine principeJ societies, and, in addition, there are uumarous
smaller societies established for individual mines, having in the
main the same objects as the larger ones.
Something more is needed — 'viz., relief in sickness, and old
age pensions for alL Some of the existing clubs of individual
mines give sick pay to their members, and. there are the ordinary
IViendly Societies established on a far firmer basis, which can be
resorted to by the miner like any other workman. As far there-
fore as sickness is conoemed there is machinery available by
which the miner in any part of the kingdom can make the neces-
sary provision for himself and his family.
If he requires a pension, he con get (me upon the very best
security by going to the nearest Post Office, A young man of
twenty can obtun a deferred annuity of 5*. a week, commencing
at the age of sixty, by paying £2 $a. 4d. a year, or lod. & week.
If the person wishes to discontinue his insurance, he can do so,
and all the money he has paid will be returned to him, provided
that an instalment of the annuity has not become due. However,
OS the facilities afforded by the Post Office have not been utilised
to any great extent, compared with the numbers of the working
classes, and as a large number of persons spend the last years of
their lives and end their days as paupers in the workhouse, it is
thought by most people that something more should be done. Great
' Op.at. Tables IV. and T., pp. 34-5.
.vGooglf
694 ORE AMD STONE-MINING.
difference of opinion exists upon the subject; much hoe bem
written, and still more said during the last few ye«r8, and th^
cODtrOTets; has nged mainly upon the question of State aic.
The proposals may be Bummed * up as involving one of the three
following prindplee :
1. State endowmeot.
2. State Mtistsnoe.
3. State oompnliloii.
I. The first, that of Mr. Charles Booth, means the free gift hr
the State of a pension of 5*. a week to every dtmai on attaining
the age of sixty-fi.ve yean.
3. The beet known scheme coming under the aecond Iiead u
that propoaed by a Parliamentary Committee.f preaided over br
Mr. JoGeph Chunberlain, M.F. Its main features are aa follows:
If a young man pays ^$ to the Post Office Savings Bank befoie
the age of twenty-five, he is to be at once credited with j^if
more from a State pension fund ; he will then have to pay j£i 1
year to the Post Office for forty years, and at sizty-five he sii!
become entitled to a pension of 5a. a week. If he dies before tin
age of sixty-five, there are arrangements for granting a penaon
to his widow and children. It is also proposed that a nmle shall
be able to purchase a pension of 5s. a week on payment of oae-
half of the sums just mentioned ; but in this case there is no
provision for a family.
3. The last plan of providing old age pensions ia that wbirli
baa been advocated for so many years and with so mn<^ ski]] by
the Bev. Canon Blackley. He would compel eveiy one to de-
posit with the State, before the age of twenty-one, a sum of about
j^io, which would suffice to provide \™ with a pension of zi.
a week on attaining his sixty-fifth year. Canon BlacUey poinU
out that in his youth, before marriage, a man would be able to
make the proposed saving, and that after this he would do
longer be troubled by the thought of not being able to keep up
his payments.
Many arguments may be adduced in favour of each of the
three principles of old age pensions, but opinions coaoeniiiig
them must largely depend upon the "personal equation" of tbf
individual — that is to say, upon his general views regarding th«
interference of the State in such matters.
The Gordian knot of this difficult question has been cut in
Germany by the Iaw of Insurance against Old Age and Infirmitr^
passed in 1889. Under this law the means for providing tlie
allowances to infirm and aged persons are made up of (xsilanbd-
• ReporU of the ChUf Begulrar 0/ FriewUi/ SocUtiet for tha I'ear 1891,
London, 1S92, p. 26.
f Tht Jhaat London, JSkj 31, 1892.
t Tranelated in Parliamentary Paper (C— 5837), 1S89, price 3l(/.
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CONDITION OF THE MINER. 695
tions from the Btate, the employers and the persoiu insured, the
two latter paying like amounts.
The method of insurance may be briefly described as that of
Stato compulsion with State aid, together with obligatory coutri-
botions from the employer. This bold experiment wQl be watched
with inter«st.
This subject of dirift mnst not be concluded without a few
words about one requinte for the treatment of diHeases — viz.,
hospitals. In this country the provision of such institutions is
frequently left to private benevolence ; in the great tin mining
centre of Bedruth, for instance, the burden of ensuring accom-
modation for the sick and injured has been taken by a charitable
owner of mineral property. According to the balance sheets
ai the institation from 1885 to 1892, he has paid on an average
more than 40 per cent, of the total coet, which exceeds ^^1300
yearly ; the remainder ia met by contributions from private per-
sons, companies working mines in the neighbourhood and their
workmen.
The Oakeley Hospital at Blaenau Feetiniog, which ministers to
the ills of some of the quarrymen, was built by the landowner,
and is now supported by the largest slate mine.
Many of the large Continental mines keep np establish moots of
this kind, and throw them open gratis to tbeir employes. The
same plan is adopted by some of the large British cumpanies
working mines abroad, and even at Boiyslaw, where much of the
mining is being carried on in the most primitive manner, a Gali-
cian company supports a small hospital, and admits not only its
own servants, but also any urgent cases requiring BurgictU or
medical attendance.
Fortunately, it often happens that a mine has not accidents
enough to require the constant use of a hospital and the entire
services of a surgeon. This is the case, for instance, at some large
mines near Ems ; the company has built a hospital and keeps it in
readiness, in case of accidents or sickness, with a doctor on the
premises ; bat, in consideration of his small stipend, lie is allowed
to have three rooms at his disposal in which he can treat private
patients. In the United States sick and injured miners sometimes
go to private hospitals, which are managed by medical men.
Before complete recovery from an illness or the effects of an
accident, a man passes through a period of convalescenoe, during
which he requires little medical aid, but depends for his final
restoration to health mainly upon good food, quiet and regular
living, and plenty of fresh air. It is a question in some mining
districts whether it is better to support a convalescent home in the
locality itself, or to subscribe to one at a distance. The latter
plan is in many cases cheaper, owing to the smaller coet
for general ^>ensee ; and at the same time it is better for the
patient, who prcAta by the change of air and scene, which in
.vGooglf
696 OEB AND STONE-MININa.
themselTea are powerful rsmedi&l asente. In a small island like
oura, it is not difficult as a rule for the patient to get to tlie
sea coast without a rainoua expenditure of money in railway
fares. At some of the sea-aide convalescent homes a min^ may
be boarded and lodged for three weeks at a total cost of £1 i6t. ;
therefore if a mine is employing 500 men, and each man sub-
Bcribee ^ per month of four we^s, more than ^13 can be nueed
annnaUy, or sufficieDt to give seven invalids a stay c^ three weete
each at the sea.
In writing upon the question of thrift, mention must be made of
co-operative societies, which give the workman the opportunity of
bnying his food and clothing at the most reasonable rates, lliey
are so well known nowadays that no description of their advantages
is required ; but it is well to point out that their success doea not
necessarily depend upon their having a ver? large number of
customers, such as could only be expected in a very popolous
district. Two instances of co-operative societies in the Isle of
Man prove this fact, and show that such an institution may
prosper commercially, and do good and useful work in a mere
viJIage depending upon a mine employing only 300 or 300
persons underground,
6. SSCHSATION. — I am well aware that many will say
that in the matter of recreation the mine manager had better
not interfere at all ; I do not take this view. Men and boys
require diversions of some kind in order to refresh their bodies
after toil, and the manager of a large mine often has the oppo^
tunity t£ directing their amusemeuta into the beet channels.
Tastes diSer: some men will find relaxation in reading, and
vill be glad to be able to borrow books from a library ; others
are musioal, and will prefer to join a bond ; boys, in spite of hard
bodily work at the mine, will delight in active gamee as soon as
tbey are free. As an example of what may be done I will cite the
namee of the clubs established at the collieries of the Douchy Com-
pany in the north of France as recreative institutions : Archers,
croesbowmen, gymnasts, philharmonic, and pigeon fanciers. It
will be seen from this list that a great many different tastes
have been studied in order to encourage the men to employ their
spare time in a wholesome manner instead of going to pot-houses,
to the injuiy of their purses, if not to the detriment of tb«r
health.
An example on this side of the Channel may be taken from
the extensive oollieriee in Derbyshire and Nottinghamshire,
owned by Colonel Seely, M.F., who has established workmen's
clube, cricket club, football club, pig club, a band, and an nnnual
Hower show for the benefit of his men. The cricket ground is
one of the beet in Derbyshire, and the club-house is a large build-
ing containing three billiard-tables, reading and smoking rooms,
and a lending library ; the members can obtain any sort of
.V Google
CONDITION OF THE MINER. 697
refreeliment they like at reason&ble prieea. The band p]ays
three times a week in the club grounds. In addition, each sepa-
rate colliery has its olub with a billiard-tAble, and other appli-
anoes for recreation. All these institutionfl are under the control
of committees of the workmen, presided over by the General
Manager,
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CHAPTER XVII.
ACCIDENTS.
Dekth-nta of mincn tnm looIdeDtt— BektlTe Booident mortally oDiier
fTOond and above groimd — Fatalltie* : aDdargroncd, from &II1 irf
roof, from aooidente Id thafts, from blasting aocId«iit«, from Qnda-
KTOond fins, from imptlona of water and sandij oQi&t oaiuM—
Aooidonti above gronnd — Boiler eiplodoiu — Non-urtal accidents—
AmbotaDoo traiolng.
Few persons will deny the dangers of the mlner'B calling ; some, how-
ever, consider that the public form an exaggerated idea of these
perils from dwelling too much upon occasional colliery explosionE.
Death-rate of Miners from Aooidenta. — In the firat place
comes the question : What is a dangerous trade ? If we look &t
the vital statistics quoted from Dr. Ogle in the last chapter, it
appears that the majority of miners, thanks, partly, to their
starting originally wit^ a more than average good oonstitution,
lead a longer life than many tradesmen in towns. In spite of
the diseases and accidents to which he is liable, the average miner
is better off than most people would have supposed, before tiey
became acquainted with the figures. On the othsr hand, if we
limit our attention to accidents, we find that the miner gets far
more than his share.
It may be asserted without fear of contradiction that a calling
with au annual mortality of i per 1000 from accidents, is
hazardous. The statistics concerning accidents in tliis oountiy
are given annually in the statistical summaries , prepared by Her
Majesty's Inspectors of Mines; and it will be seen from the
published figures that, taking all the mines in the United
Kingdom and including casualties above and below ground,
there was an average annual mortality from accidents of 2*18 per
1000 persons employed during the ten years 1873 to i88z inclu-
sive, and that in the next derade the mortality dropped to I'jS
per 1000.
In this country an accident is classed as fatal if it causes
the death of the injured person within a year and a day cf
the date of the occurrence ; it is therefore possible that in
certain very rare oases, when more thaa a year elapses before a
man succumbs to his hurts, an accident may be registered ss
non-fatal, although it finally turns out to be fatal. Cases of
.V Google
ACCIDENTS.
699
this kind are bo few that the correctnem of the British Htatistics
cannot be appreciably affected by them.
In an intereeting report upon the Exhibition held in Berlin in
1S89 of appliances for the prevention of accidents, M. Fanl
llabets givee a careful eummary of the progreea realised in
Belgium, France, Great Britain, and Prussia* He divides his
results into periods of ten years :
Table I.
Annval Death-rate from Accident* per 1000 Penone Empioytd.
Period.
Bd«lnn..
Fiuw.
OnitBriUiD.
^.
1851 to i860
■861 to 1870
187 1 to 18S0
1880 to 1888 .
213
If
157
407
33*
23S
194
air
•1853101860. -f 1S51 to iB«a
These figures show a steady diminution in the number of
accidents nxoeptingin Oermany, for in the decade 1861 to 1870
the mortahty was terrible ; hut even the most favourable averages
are far above the standard of i per 1000, which has been assumed
as the mortality ratio of a dangerous occupation.
Belative Aooident MorteJitr amongst TJndergroimd and
Above- ground Workers. — Descending into details, let as
examine how the two classes of mines — viz., those under the Coal
and those under the Metalliferous Act — compare with one another.
The figures will be made most plain by putting them in a tabular
form.
T&BLC II.
'w:'
Annga Unnbrr of
. Anno»CJ?°°^
TWU NBnbw at .„-_ .„„„, „-,h
Uiuea Dla»ed under the Coal Uinet Regclatiou Aot.
i873toi8Sz| 503.428 j 11,394 1 2143
1883101893! S7'.7i9 1 10.3^7 1 "-806
Mines clasaed under the Hetalliferoui Mlnea BeKulaUon Act.
1873 to 1882 SS.388 1 909 1-641
1883101892 43,481 613 r44o
According to these figures, work at minee under the Coal Mines
.V Google
7O0
ORE AND STONE-MINING.
Act presentA decidedly more perils than work at miiies aodo' tiie
Metalliferous Act. Speaking roughly, the relative decrees of
danger were as i I'to S in the first period aud 9 to 7 in the second.
In order to make the comparison of any real value^ it is neces-
sary to go somewhat further. Oaring to the amount of labour
required for " dreesing," the proportion of Borfaoe hands is much
larger at a tin, copper, lead, or ^te mine, than at a oc41iery. la
round numbers about one-fifth of the persons employed at minw
under the Coal Mines Begulation Act work above ground, and four-
fifths underground ; at mines under the Metalliferous Uines Act
the proportions are two-fifths above ground, and three-fifths nndet^
ground. Consequently, as the proportion of the surface hands
with a small risk is twice as great in one esse as in the other, it is
impoflsible properly to compare the risks of the undergretind
workers until this souroe of error has been eliminated, ^te
death-rates calculated separately are as follows :
Tablx III.
Average Artnvat Death-rtUt from Aeddenta per 1000 Pgrm>j>M
emphyed in and about the Mint* of tht United KingdoiK of
Qnoi Britain and Ireland.
DtCMUlilParlod.
B.U«0™od.
AbonOroDDd.
C<»lHlMt
Am.
ii>t>iiir«»
2-MS
Col Kiiwa
AOt.
MeUlllftrou
MtsaAct.
1873 to 1881 .
1883101892 .
i-oog
0-919
0-9S9
0-578
0-392
In the first period the relative amounts of danger to under-
ground workers ware as 51 to 47, a very different proportion
from II to 8 as appeared from the other table; in the eeoond
period the mines under the Coal Mines Act have the advmntege,
whereas by the original table they seem to be more dangerous
than thow under the Metalliferous Act.
The neceaeity for considering the underground death-rate
separately, when inquiring into the relative amounts of danger at
different classes of mines is well illustrated in the case of the
underground slate quarries of North Wales. These appear to be
less dangerous than collieries, or more dangerous according as
the surface hands are included or not in the calculations. Taking
the ten years 1875 to 1884, the annunl death-rate from accidents
at the underground slate quarries was 2-07 per looo among all
the workers as a whole, and 3-2 per 1000 among the under-
ground workers taken separately. The former rate is better than
the corresponding 2-243 (Table IL) of mines under the Coal Minw
.V Google
ACCIDENTS. 701
Act, imd the latter is worse than 2-572 (Table III.). Godbo-
quently the avenge undergroimd Blate-qoarrier has a more
periloua calling than tlie average collier.
While correcting one mieapprehenBioD Z most guard against
another, and point oat that the Coal Uinee Segnlation Act applies
to mines of coal, stratified ironstone, shale, and fireclay. Therefore
the figures given do not refer solely to coal-mines, and do not re-
present precisely the risks of the collier, and it becomes necessary
to examine whether the introduction of certain disturbing
elements affecte the average risk to any great extent or not.
Compared with coal, the amounts of fireclay, ironstone, and
shale are small, and the total quantity of these minerals raised
in 1893 was lees than 6 per cent, of the weight of the coal ; any
error caused by the introduction of ironstone and other mines, is.
likely therefore to be inconsiderable. After coal, the most
important mineral wrought under the Coal Mines Act is ironstone,
and more than half the total quantity raised is obtained in the
Cleveland district. From the figures given in the reports of the
inspectors of mines, I find that from 1873 to 1882 there were rSj
deaths from accidents underground in the Cleveland district,
with an average annual underground staff of 6863 persons, con-
sequently the average death-rate was 2*66 per rooo; in the
following decennial period it was 2*21 per 1000.* Both these
proportions are higher than the corresponding ratios calculated
for the whole of the mines under the Coal Minee Act; therefore
if all disturbing factors were eliminated, we may fairly assume
that the average underground death-rate at the coal-mines proper
did not exceed the figures given iu Table III.
On the other hand, I must remark that the Metalliferous Mines
Begulation Act applies to all mines not included under the Coal
Minee Act, and the statistics under the former Act refer not only
to mines worked for ores, but also to salt-mines and underground
slate and stone quarries. The figures quoted cannot be taken as
relating solely to true metalliferous mines.
For the sake of comparison I have extracted from the annual
reports of the inspector of mines, the figures for the metalliferous
mining district of Cornwall and Devon, including also a few
mines in Somersetshire and Dorsetshire. During the ten
years r873 to 1882 there were 280 deaths from accidents under-
CTound, with an average underground staff of 10,629 persons.
This means an average annual death-rate among the underground
workers of 2*63 per 1000. The corresponding figure for the ten
years 1883 to 1892 was found to have been 254 per 1000.
The oonclnsionB arrived at from these statistics are, first, thab
* From 1873 to 1883 the published Btatlatios rsfer to the whole of the-
North lUding of ToilAiire, where a little coal is worked, bnt not in sDffl-
dent qnantitj to affect the ntios pereepliblf ; ainoe 1883 the Clefeland
figares have been kept entirely separate;
.vGoo»^If
702 ORE AND STONE-MINING.
the minee under the Coal Mines Begulation Act are not altnys
more destructive of life thftn the mines under the Metalliferoos
Mines Regulation Act ^and secondly, that certain mines vorkedfw
metallic ores, such as the iron mines of Yorkshire, and the tin sad
copper mines of Cornwall and Devon, present more dangers to the
uoderground worker than an average collierjr, in spite of tbe
almost complete absence of explosions of gas. In other words, as
has been pointed out repeatedly, fire-damp is not the worst enemy
the miner has to contend with. It is very evident also that i
different classes of mines are to be compared as regards dangeis,
the figures must be r«etricted to those working below ground ; end it
is to be regretted that some of the official reports concerning mines
in other countries afford no means of making the proper compa-
rison. Ontheother hand, foreigners sometimes complain that our
British statistics do not give them the true coal-mining accidents
separately ; but when the two minerals, coal and ironstcme, are
being worked in the same pit, and when the preliminary and
exploratory work is common to both minerals, it is impoedble to
draw any strict line of division.
ClasBiflostion of Aooidenta. — In order to obtain some general
ideas conceming the tdnds of accidents which occur at mines we
must begin byt^usifying them. The basis of such a classification
may be either the place where the accident happened, or the
cause of the occurrence. Usually the classification is founded
upon both.
Following the plan which was adopted in the early days of
mine inspection in this country, the British classification begins
by separating the accidenta which happened underground fram
those which took place at the surface, and then the underground
accidents are arranged under the four main heads :
BnlosioDS ot Sre-damp ot coal-dust.
Falls ot grooad.
la shafts.
UisoeUaneoui.
The classification is not strictly logical, because it to a certain
extent mixes up cause and place ; there may be explosions of fire-
damp or falls of ground in shafts, but these would naturally be
placed under the headings which most particularly describe them,
so that the heading " in shafts " does not always include every
accident which has happened there. However, the classification
has been used so long, and is so well understood, that it would be
absurd to make any great alteration now.
The relative importance of each of these classes is brought out
by the following table, which has been calculated for the same
periods as the preceding one :
.vGooglf
ACCIDENTS.
Table IV.
AUtha
Ur»ou Hln»
thaCoid
Clanlind
DliBrloL
part of
8oiB.n»t
ElndtfABidtnt.
III
1
P
■
III
•s
i
lljli
I'J
r4
H
i'i\h
TK» YB4B8— 1873 TO 1881 ISOLDHTB,
. EiplOBions of
& "g flre-damp
1 ' '
2620
2V1
4
cS g. IQ abaft! .
" Mlsoellaueoiu .
4534
40-1
313
W4
9*
447
1303
11';
241
107 320
1907
17-0
227
2li-0
75
88 ,16-3
Above gionnd ,
Totals .
911
■
8-1
100
23
HI
«
16-2
IIZ94
100
909
206
.<»
w
,00
Ten YBAsa— 1883 to 189a ixclcsivb.
b-% fir&dAmp
li
14M
M'l 6
i-o
S a FaUE of groimd
A E In Bhafta .
4602
44-6 ;! »38
18-g
83
6V4
S
^hi)
2316
160
27-6
61
M'fi
Above groDud .
TotaU . .
IO-3
67
10-9
14
107
34
117
10327
,00
6u
lOd
131
.„
^
,00
The further sabdivision adopted in thin coimtiy for clasei^ing
is given in the teble below :
.V Google
ORE AND STONE-MUflNO.
UHBZBSBOintD.
ClaaaifieatioH of AoadaOt.
BxpLoeiOHB OF Fibb-Damp OB COAI-DUST.
FAixa OF GBOUND. j^ ^^ «^^
IOvBTwiiidli^.
Ropes Bud chains bieskiiig.
Whilst uoandicg' or desceadinf br
mscbiaeix.
F«llliig into shafts from nd»ee.
niings UUug from mfiwe.
Falliog from part wajr down.
Things bUing from part in;(bn>
MisceUaneons in shuts.
) Explosions of gonpowdw, kc
Snffooation bj gases.
Irmptioni of water.
Falling into vator.
Oq inclined planes.
Bj trams and tubs.
UlBOBLLANKOUe.
By macbinei? on surface.
Boilers bnntinc.
On railways and tramwR/e.
MisceUaneons on surface.
ExplOBioiu of Flre-Damp or Ooal-I>uat. — With hw enr}-
tione, fatalities from explosions of firs-damp in this country an
confined to coal mines.
Falls of Groimd. — Table IV. indicates plainly what post
requires the special attention of the mine-owner, in his endeaTOvn
to ward off the dangers which threaten his worlunea. 'BjUi^
largest proportion i^ fatalities occur from falls of ground ; and tin
same story is told by the statistics of other countries. Witho*
attempting to refer to all the information which is published at
the subject, it will suffice to say that 36 per cent, of the desthe •>
Prussian* coal miuee in 1891, and 47 per cent, of those at the on
mines, are ascribed to this cause. This cannot be a matter of
surprise when we consider the conditions under which the m'D^
carries on his labour : in the overhand stopes of an ore mine, hs i^
constantly taking down the roof above his head ; in working amji
stratified deposit, he is continually pushing forward under a if^
part of the overlying stratum, whi<^ may have concealed and un-
suspected joints ; at other times, he is engaged in removing ^
the parent bed huge masses of rock weigfajng- many tons each;
no wonder, therefore, that he is occasiooally caught by a UL
These accidents are best guarded against by incessant vatchfol-
nees on the part of the men and masters, by putting in eap]W^
even when they do not appear immediat-ely necessary, and pJ
• ZeitKhr./. B.-S.-u. A-Weien, toL xL, 1893, p. 3a.
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ACOIDENTS. 705
regulations definiog how closely pi-ops sball be eet. Testing the
grouod by " Bounding" — i.e., hy striking it with the hammer and
noticing the sound emitted — often enables the workman to detect
whether the rock is firm or not ; but the indication is not always
reliable. If the maae of rock is laz^e, it may '' sound " all right,
and yet not be firmly attached as supposed. Besides, ground
which is perfectly firm and safe when first laid bare by the miner,
will often lose its stability with the lapse of time. Air and mois-
ture penetrating into the minute concealed joints and acting for
months or years have the effect of gradually loosening the adher-
ence of the rock masses ; the constant shaking produced by
blasting, to say nothing of minute but oft-repeated earth tremors,
are all acting in the same way, and therefore the miner has no
right to conclude that places which were safe originally are going
to continue so for ever.
Shaft Aooidents. — The principal dangers that beset the
miner in shafts are manifest from the difierent headings, and
many of the means of guarding against them have already
been explained in the chapters upon winding and descent and
ascent. It must not be supposed that all the accidents classified
under the third heading in the British statistics occurred during
the ordinary times of going up and down ; this division also
includes fatalities which took place while men were occupied in
making i-epairs, or were using machinery not intended for the
purpose of raising men. The German official statistics contain
a table in which these irregular ascents or descents are eliminated,
and make it possible to institute a comparison between the relative
degrees of ^ety of the diiferent methods of obtaining access
to the workings. Judging by the result of the ten yeara 1881
to 1S90, the death-rate from accidents per 1000 persons was
0-060 with the cage, 0-066 with ladders, and 0-196 with the man-
engine ; this last contrivance is therefore far more dangerous than
the cage or ladders, although the list of man-engine fatalities was
not swollen by any big catastrophe, such as happened in the
previous decennial period. A distinction must be made between the
single-rod and the double-rod machines, and the Prussian statistics
include many of the latter. It will be readily understood that
a fall in a naked shaft with few fixed platforms is far more likely
to be fatal than a fall in the shaft of a single-rod machine, which
is closed completely with the exception of the small manholes
at intervals of 12 feet. As far as I am aware, no accident on a
single-rod man-engine in Cornwall, even when a rod has broken
with men on it, has ever caused more than one death ; but there
are two bad cases on record with double-rod engines in Germany.
In the year 18S0 eleven men met with their death at Abraham
mine near Freiberg by being precipitated down the shaft when one
of the Toda broke while they were " riding " upon it. It appeared
from the official inquiry that the timber rod had become rotten.
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7o6 ORE AJUD STONE-MINING.
and that it ought to bare been changed long before the udikn.
The other bad fatality was at Boeenhof shaft near Claiuthal in tbi
Haitz, where again eleven poor miners were Buddenly killol km
a similar breakage. Thette two accidents prove the isoorredna
of the statement made by those who extol the man-engine at llit
expense of the cage, and say that no accident can ha^^ieDwithih
former except through the miner's own carelesaiiees ; butvha
malring any sQch oomparison it is essential to know pnrisdi
which kind of man-engine is meant. Thus if we take theca.'scc
Cornwall, where the double-rod machine no longer exists, we id
jnst the reverse of what appears in Prussia. The death-rate frat
accidents on man-engines in Cornwall and Devon during tfae^nt
years 1873 to 1879* ^** °''4 P*^ ^°°° persons using them, «&
the annu^ death-rate per 1 000 persons using ladders wss hi|^a-
viz., o'si. If the actual distance traTelled had been taken iiit'
acconnt, the scale would turn more decidedly in f&voui ol tt^
man-engine.
In the Prussian figures just quoted, the ladder appeusto
little more dangerons than the cage ; probably most of the miii^
provided with ladders are much shallower than those fitted ni
cages, so that if the men had been obliged to ascend from tifi
depths in both classes of mines, the list of ladder scades:'
would no doubt have been largely increased.
Hie Belgian machines, called warooquiret after their at
structor, are rendered safer than the Hartz or Saxoo mu^
engines by having a railing round the back of each pUtiiA
on the rods. Some of the double-rod machinee are made "li
large platforms, so that two persons can stand on them.
KiBoellanooua AooidentB Undergroand. — ExjJatmi •-,
Gwipowder, dv. — Blasting accidents, which head this class, an
possibly less numerous than many people would suppose, <bs
reflecting upon the large quantities of gunpowder and other non
powerful explosives which are annually consumed by the nuDei.
They occur in many ways :
a. Accidental ignition of powder, while carrying it or hsiidlu:
it, from a spark of the candle.
6. Getting in the way of blaste, either from not retiring to s
safe place, or from a hang-fire of the fuse, or from errooeaii;!'
supposing that a fuse had not been ignited by the "snuC
0. Ignition of the charge during the operation of tsmpim
Sometimes, no doubt, a spark is struck by an iron rammer ti'
communicatee fire to the charge by a train of powder lying at''^
behind the fuse or in ragged portions of a hole bored in " rofg
gitinnd; in other cases it is thought that just as Gemu
tinder can be ignited by the mere compression of air, go ''
• BtporU of H.M. Intptcnn of M'mu for the Year 1879, London, rfe
P- 435-
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ACCIDENTS. 707
cbEurge itself may be fired by hard ramming at tbe commeoce-
nteot. The number of accidents of this claaa haa been reduced
by the introductioD of the nitroglyoerine explofiiTeB, which will
exert their oaeful eSect without hajrd tamping.
d. lUeg^y boring out or picking out the tamping of boles
which have missed fire,
e. EEudation of nitroglycerine from dynamite left exposed to
water in a hole which has missed fire. The seasitiTe oil may explode
when tbe adjacent rock is struck by the pick or drilL
J\ Unexploded remnants of dynamite or gun-cotton. It occa-
sionally happeoB that the whole of a charge of one of the
nitroglycerine or pyroxyline explosives does not go off com-
C'lely : after firing a shot the minsr may find that tbe blast
not rent the rock to the bottom of the hole, but has left a
"socket"; to save himself a few inches of boring, he sometimes
is tempted to use this in starting tbe next hole. Suoh proceed-
ings l^ve been proved to be most dangerous, for the blows of
the steel tool may fire tbe unexploded remnants, and cause a
serious disaster.
ff. Miners, and indeed others, have been injured by the
explosion of the fulminate of mercury in the detonators, or caps,
when examining them incautiously, or while endeavouring to pick
out sawdust with which they were choked.
The golden rule is to treat explosives as substances which will
and do explode, but it is naturally difficult for tbe miner who is
handling them day after day not to become somewhat callous to
their dangers.
Suffocation by Goats. — Few fatalities in this country are pat
down to sufibcation by gases given ofi* naturally by the rocks.
Irruptuma of Water. — Irruptions of water into mines happen
in three ways :
Floods at the sarface due to an uDprecedeuted rainfaU.
Exteadlug the workiiigatoo dosetotha bottom of the sea or a river.
Breaking into old workings full of water.
All these causes have occasioned disasters in mines. The first
danger may be avoided by keeping tbe top of every shaft of the
mine well above the level of the lowest I^d of tbe district. If
it happens that tbe only convenient site for a shaft is near the
bottom of a valley, the top may be built up with masonry strong
enough to resist a flood. Many lives were lost in Hungary in
May 1892, from the bursting of awaterspout, w^icb caused water
to pour down some mine shiiits.
Breaking into the flooded workings of old adjacent mines may
happen through want of knowledge or want of care. Defective
plans are one source of the irruptions, the ^"'"1^ being beguiled
into a false security by inaccurate surveys of the adjacent property,
or by ignorance that any workings had ever been made there before.
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7o8 ORE AND STONE-MINING. •
The Coal Uinee Act enjoiaa the precautions which Hre well tocvt
to every miner in approachiDg old workings — viz.., boring hcJ» t.
lidrance for the pui-poee of tapping the water, before there if tn'
danger of the protecting partition giving way under the prej-scp
behind it. The water can then be drained off slowly, and 'i'
partition need not be broken down until all chance <rf flooding t
past.
On Indiiud Planet. — Accidents may happen from men beii.
caught and knocked over by waggons, while they are m«Hng e.-
of inclines as travelling roads ; the statutory mMiholes or lefcr-
niches are designed to prevent dangers of this kind, but a beti^:
plan is to provide independent walking roads, or to partition c!:
the walking road from the railroad. At some minee the men a>
prohibited from walking upon the inclines while trucks are b^'c
drawn up and down, and work is stopped at the chaagea of tk
xhifts, in order to give them the means of descending &l:
ascending in safety.
By Tramt and Tubs. — It would he strange if men -were &t
wmetimee injured when moving tram waggons. Owing to i:
imperfection in the road, a waggon may turn over and catcb i
man in its fall, or in narrow levels a man may be nipped agains;
the side.
By Machinery Underground. — Proper fences Vfill prevent soil
of the fatalities from machinery underground, and such safegowi^
become all the more necessary in the dark or ill-lighted passa^
of a mine, where one may have to assume a cramped positico] ii
going past the moving mechanism.
Sundriet Undergrcwnd. — Under this heading vnH be foor.i
various accidents which cannot be placed in one of the other sol-
divisions. The most serious are underground fires ; in fact, two c:
the worst catastrophes known in mining have happened from thi-
cause; they are barely equalled by the worst explosions in ooUierie!.
and go to prove a fact already insisted on — viz., that coal tnjnipr
is not the most perilous form of underground labour, I refer
now to the underground £res at De Be«rs diamond mine and ti
Ffibram. In the year 1888 some of the timber in one of th«
shafts at De Beers accidentally took fire, the flames spread rapidiv
and soon filled the mine with smoke to such an extent tba:
twenty-four white men and zoo natives were suffocated. Tbf
PHbram disaster of May 1893, was on an even larger scal<>.
Again, some accident or carelessness caused the ignition of the
timber in one of the shafts, and the burning wood produced
suchfumes that 318* persons were asphyxiated in the mine, whils:
one died a few days after his rescue.
These are not the only cases of great disasters arising from &re>.
* "Dsr QmbeiibraDd Id Pribram am 31 Hal iS^,'' B, «. h. Z., 1E93,
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ACCIDENTS. 709
At the Mauricewood Collier;,* in 1889, sizty-tbree out of aixty-
fire men who were in the mine loBt their lives through an under-
ground fire, the cause of which was never precisely aacei'tained ;
poesibly a naked light carried on the head of one of the men came
in contact with the very dry timbering on an incline or with some
brattice cloth, and set it on fire. The accident was in no way due to
tlie fact that the mineral worked was coal. Turning to ore mines,
we find, for instance, that fires have happened on more than one
occasion in the workings on the Comstock lode. Before the year
1869 tfaey fortunately had no other evil effect than driving the
men out of the workings; but in April of that year a fire broke out
in the 800-foot level of the Yellow Jack mine, possibly from a candle
left near the timber, and it burnt along unnoticed until at last
a " stall " gave way and drove a blast of foul air and smoke into
the shafts. This happened at the change of shifts and thirty-four
miners were suffocated.^ After unsucceasful attempts to rescue
the men, and when all hope of their being alive had been abandoned,
steam was forced into the mine two days after the accident for
seventy-two hours. This proved inBufficieot, and steam was again
forced in for two days, The fire was not completely subdued for
several weeks, and even six months after the accident, smouldering
timber was sometimes met with. According to the experience
gained in this accident, steam is not effectual in extinguishing a
mine fire, though it is useful as a temporary expedient for purify-
ing the atmosphere of the mine and checking the flames, and so
rendering it possible to put in dams and cut off the supply of
oxygen to the conflagration.
In addition to the big catastrophe, there were several minor
accidents of a like nature, and forty-nine petsons in all lost their
lives from underground fires at mines on the Comstock lode in
seventeen years. X
A fire at the Calumet and Hecla copper mines on Lake
Superior in November 1888 claimed eight victims, and in addition
to this loss of life caused a considerable loss of money. Judging
by the accoants which are published from time to time in the
mining newspapers, underground firesare not so uncommon in ore
mines as one might suppose, and it may often depend upon a mere
chance whether they become fatal to life or not. With a mineral
BO easily ignited as native Bulphur,§ the occurrence of fires in the
Sicilian mines will not excite astonishment ; some of the accidents
arise from careleesness with lamps and in blasting, but the most
common cause is the heat generated by the friction of heavy
* JahnBton and Bell, "Haorloewood CoIUnj, Meport to tht Steretarg
cf Slate for the Homt Departmtnt," EdinbDrgfa, 1S9OL
+ Lord, " Conutook Minw and Miners." Monogn^ht U.3- Qed. Saruty,
vol. iv., WuhingtOD, 1883, p. 169.
t Op. ri(., p. 404.
I Sivuta ilit Hervkio Minerarlo ml tSSS, Florence, 1890 p. 7a
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7 to ORE AND STONE-MINING.
tuasses of the enlphur -bearing rock when there are foils, whidi. a
has abeady been stated (Chapter VI.), are sometimes the nsdi i
the method of working adopted. Many of the fires lut fa i
very long time, and in one instance sixty years elapsed befowtbi
baming rock was extinguished. The nomber of acddenta hrm
snflbcaUon by sulphurous acid produced by undei^round fine a
the Sicilian mines is by no means small ; thirty-five perans
perished in this way daring the five years 18S4 to i883, to si
nothing of four deaths from inhaling carbonic acid gw, i^d
thirteen deaths from sulphui-etted hydrogen.*
The moral to be drawn from these unfortunate acddents is tk
at all events the main shafts, or other t^proachea to the mis-
ground workings, should be constructed in a manna* ealcuUtell^
prevent a repetition of such great disasters. Many of the ebth'
in mines, especially those devoted to pumping;, are so wet ^
there is no fear of a fire even if they are lined with timber; ia
others the lining is of brickwork or masonry, and the gnidfe uf
made of steel huIb or wire ropes ; the shaft is therefcre uninfli^
mable. In very dry mines, on the other hand, the dtmger iaf
exist of the shaft being converted by some slight carelessneo."
by an accident with a lamp, into a huge blazing fumaec, ^'^
may send clouds of sufibcating fumes into the workings and fR-
vent the exit of the miners or the entry of rescuers. To gu>n
against such a state of things, either timber linings maf « '
eschewed and replaced by incombustible linings, or the \nS^^
malnlity of the wood may be reduced by keeping it dsjop. i> ,
already pointed out, water is in some casee made to trickle ova
the shaft timber in order to prevent its being attacked ^
dry rot. ■
I have dwelt somewhat at length upon these fatalities fr^
fires, because of the very serious consequences which hare reau^ 1
from them in recent years.
Before passing on to the accidento which happen at the soiw
it may be well to call attention to two recent rescues of eotOTilw
miners, as instances of the length of time men can exist iritlioai
food, 80 that in case of the accidental imprisonment efforts ^^
recover the sufferers may not be relaxed too soon. In July ■*?'
three miners were ehut in by a fall at a brown-coal mine a
Bohemia, and were rescued after the lapse of no less than eerente^
days, during the whole of which time they were deprived of if""'
though Bufiiciently supplied with drinking water, A shade kid'^
wonderful is the escape of four men at Jeansville in FenuByl^u^
in February 1891. Sevent«en persons were shut in by theirwf
tion of water into the mine from adjoining workings, and tnet
could not be reached until the level of the water had been '"■'^
by pumping. When the rescuers were able to penetrate into uii
" Op. cU., p. 54.
f EJtg. Mm. Jour., Tol. II. 1S91, p. 447.
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ACCIDENTS. 711
workingB, eighteen days after the disBSter, four of the BdT«uteeD
men were found alive, though of course extremely weak.
Aooidente on the Burfiwe.— 5y McuAinery. — A veiy large
propoi-tion of the sarface accidente are such as might happen at
any factory. Though they cannot be prevented entirely, for men
and boyB will eometimes go into the most unexpected places, much
good can be done by fendiig ; and it is always well to err upon
the edde of over-caution, and protect shafting or other moving
parte which may at fimt sight seem quite innocent. If the
lubricant cannot be supplied by one of the constant feeders, the
attendant should do the oiling, as for as possible, when the
machinery is stopped for meal-times or for some other purpose ;
the desirability of wearing tightly fitting dothee has already been
mentioned, and it ia always advisable to have the means of
throwing machinery out of gear quickly, in case a person is caught
by it.
For putting belts on to pulleys, a special " shipper " is safer than
the hand.
Now that BO many mines have orcular saws, it is well to
recollect th&t the use of a guard, like the Lakeman guard foi-
instancy may occasionally save a man the loss of a finger or a
Looking at the fact that millions of alatee that are made annually
by machinee with revolving or guillotine-like knives, it is not strange
that through momentary inadvertence men should now and then
put the hand in a little too far and lose the end of a finger. It is
impossible for any mortal to be continoally on the watch against
such occuiTences as these, hour after hour and day after day, and
the marvel realty is that in spite of distractions the human machine
works as correctly as it does.
BoUer ExpUmona. — The subject of boiler explosiuna concerns
the general manufacturer quite as much as it does the miner,
and it has been so thoroughly studied of late years that there
is no longer any reason for aatribing such occurrences to mys-
terious and inexplicable causes. Boilers burst from weakness,
which may be due to origiaal malconstruction, to improper
treatment, or to ordinary wear and tear. It is very desirable
that every boiler should be cleaned out at least once in three months
and then carefully examined internally, a record being k^t at the
office signed by the person making the inspection. In England,
very m&ny owners c^ bailers join such a society as the Manchester
Steam Users Association and have their bt^eis periodically
io^jeoted by competont experts, who at the same time are able
to sire many valuable hints concerning safe and economical
methods of working.
Miaodtantotte on Surface. — Under this last heading are included
a variety of accidents, which need no special mention.
It would be interesting to know the exact number of accidents
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712 ORE AND STONE-MINING.
whiflh h&ppen at open works, but unfoitnnfttely do offidal 6pK
are published showing death-ratee for the whole Eingdoro, soci
as are calculated in the case of true underground miniiif.
Judging by certain returns lately published,* it seems that smt
open quarries are decidedly more dangerous than the average am
non-fatal Aooldects. — Statistics concerning non-faul uci-
dentsare of little uee unless the extent of the injury is indicsledii.
some manner. The Mining Acts prescribe that all serious dx-
fatal accidents, and all accidents causing personal injury viw
from any explodon of gas, powder, or of any steam boiler sbii:
be reported to the inspector. In France, on the other hand, ihi
ofSoial statinticst do not include non-fatal accidents which b^e
disabled the person for lees than three weeks.
Mining is aometimee a source of risk to the public as well as v
the actual workers. The commonest danger tirieeB from mifeiK^
or insecurely fenced shafts, or, what are worse, shafts «bic^
have been covered with timberaDdwnl
Fia. 709. and become forgotten. Every now »si
~~^— — ,_^ then the local papers of noiniog distriit'
record the sudden and unexpected giviu
way of a rotten "soUar," leaving'
yawning crater in what was thouglil '' |
be solid ground. Fatal accidente to ik'-
and beasts have taken place in ^ I
manner, to say nothing of many (^ |
narrow escapes.
AmbulanoeTraining. — Though pf-
vention is better than cure, and tbiN^
the number of casualties may be reduce^
it cannot be expected that mining ^
ever be quite exempt from them. 1^
vision should therefore be made U> no-
der those that do occnr as Httle h»nM
as possible. The Coal Mines Act «
1887 compels the owners of min* '"
keep a supply of splints and budatft^
ready, and many miners have lesnit u
the school of actual practice ho" ^
to assist their injured comradee brf«*
the arrival of a doctor. Nowaikp tw
establishment of classw under the i'-
John Ambulance Association^ has given the men the oppoi^'U"'^
of acquiring systematic instruction in the beet methods of f"'
* Stport to Her Majttt^f Principal Steretary of Statt far A ^i"
Department by the Quarry Commitlte of Inquiry, London, 1894, ^
mentary Paper [0.-7237.]
+ SlatiAtique de VJndvairie Miaiftde el da AppartU* i ranew w F""
en AlgirU, pour f Annie 1S86, Parig, 18SS, p. 95.
; St. John's Oate. Clerkenwell, London, E.G.
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ACCIDENTS. 713
dering first aid to the iojured, and of moving tbem without
a^ravating the mischief or causing needless pain. Miners
all over the world have reason to be grateful to this excellent
Society. Fig. 709 illuetratea the " Furley " pattern stretcher, as
Pig. 710.
mpplied by the St. John Ambulance Association, together with
the "Lowmoor Jacket," by means ot which an injured person
can safely be placed at any angle. Figs, 710 and 711 represent the
" Ashford Litter," a two'wheeled carriage for the conveyance of
the injured person along roads. The former shows that the
Fie. 711.
bearers of the stretcher can paae between the wheels, by stepping
over a crank axle, and so avoid lifting the heavy weight over the
wheeb. At large mines there should be a horse ambulance
carriage for the removal of sufferers.
Begidar ambulance corps have been established at some mines ;
probably the largest in the United Kingdom belongs to Colonel
Seely's collieriee, already notable for the aid given to sports and
paatimea. The corps now musters some 400 men, or about one-
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714 ORE AND STONE-MINING.
tenth of the tot'al number of employ^ ; the members wear a neat
uniform and are regularly drilled. Many others amon^ tbe
workmen, though not belonging to the corpe, have received
instruction in the ambulance classes. Incalculable jrood is done
by trained men of this kind, who are ready on the spot to render
first aid at any moment to ao injured comrade and superintend
his removal to a hospital ; the excellent example thus set might
well be followed in all mining districts.
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INDEX.
AbbIi and Hoble, on fired gnnpow-
Aberllefsmiy, method of vrorUt^
BlaM M, 314
AbjMtniMi tnbe wells, i yj
AoacdA, 13S
Aocld^t olcb, dadnctlou for, 639,
690
AcddenU, ouilage of injured per-
sons, 713
clataificatfon of, 704
death-rate from, 698
flrtt aid In ease of, 712
fiom eiplosives, 706
from UM» of ground, 704
from andergronDd fliea, 70S, 709
in boring, 130
in ooal mines and In metal
minea, 700
In s bafts, 705
miBCellaneona, nndergronnd,
708
non-faUl, 713
on inclined planes, 708
on thSBorface, 711
societies for relief of diatress
caused br, 691
statlBUcs of, 6^ 703
Acme pick, 153
Acts, AUatl, 665
Boiler EiploBlon, 666
Brine, Pnmidng, 666
Coal Mines Beinlatiou, 662
Eiementary Edncation, 666
Employers' Liability, 666
Explosives, 666
Taotory and Workshop, 667
Metallif erons Ulnea R^Utlon,
656
Qnury Fendng, 667
Bating, 655
relating to Deibyibin, 655
Acts — eontanud.
relating to Forest of Dean, G55
lUvers Follntlou Prerention,
667
Slate Mine*, 6<9
Stannaries, 663
Trnok,668
Adelaide drill, 195
Cornwall Connty, 435
Halkyn tonnel, 4'
Kaiser Josef lI.,TfibiaiD,434
Kaiser Josef Erbstolln, 434
Hansfeld copper mines, 434
Uonteponl, Sardinia, 435
Rothscbonberger StoUn, 434
Sntro Tunnel, Kerada, 436
working depont by, 308
Advantages ol steel supports (oc
levels, 257
Adventltions finds of valnable
minerals, 95
Aerial ropeways, 3S0
inollne, 406
Agglomeratiop, preparation for
market by, 565
Air, causes of poUutfon of, 4S0
Qomposition of, 475
evil effects of dast In, 685
friction of, 510
measiuing velocity of, 506,
S07
testing Uie qnality of, 498
Air-brake for self-acting incline,
BUbao, 376
Air-oompressors, 164
Angstrom's, i6j
Bnrckfaai^t and Weiss, 166
dry, 166
Hanarte's, 165
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Air- compreMora— (DHt( H nal.
lagta«>]l-Seigtaat, 167
iDJeotion. 166
wabei-colamn, 165
Air-carraDt, registance to, 5IO--5ia
Aii-cbTlDg, 593
Air-hose, 171
Air-lock, 378
Air-tnaina, 170
Aic-pipe lor ventflAtlDg shallow
AJT-reeervoir, 16S
QDda^p/)nDd, advantagw of,
man, 674.
of, in itaij,
S'
Algsohi mlTBr mluM, cold at, 669
Algeria, diacoverj of phosphat* of
lime In, 96
Alkali Acts a« afiecUng mines, 665
Allavial beds, mode of workii^, 391
diamond deposits, 39
gcdd-minlng, Califoniia, 318
tin ore deposits, Sj
method of worklDg, 316
Almaden, meTonrial poUonlng
among mlnen, 687
mine, J a
Alta, definition of, 11
in qnlcksIlTer mlnei, 73
Altenbei^, calamine depoMt, 19
SaxoDT, tin stockwork at, 84
AlmD-atone, ao
Aliinite,»
Amalgamation, 616
Amber, dressing of, 6t8
liquefaction of, 598
mode of oocurrenoo, 31
working for, 304
Ambulance corps, 713
training, 71Z
Americtm phosphate kiln, 594
pitch pine, 227
sjstem of boring, 137
Ammonite, Z15
Ammebug, Sweden, bed« of linc
' blende at, 87
Amorptaa canesceni, 104
Amygdaloid, oopper-bearii^, of
And^oabeii;, St, man engine at,
Angers— eonliaiMd.
slate mining, 314
Angle for ladders, J30
Angstrom's air-compcossor, 165
Aniniala as iadicators, 105
Anomalies in mineral repofiitoiie.
Antictinala, 47, 4^
Antimony ore, llquatiOD of, 59S
mode of oconrrence, 21
Antiseptics applied to timber, ijo
An^ collieries. Fiance, ahowo
baths, 681
ttael fnimea, 159
Aro-lamp at Angers, 524
Maros-Ujvar, 514
Mecberaich, 5x4
Osceola Co. 'sUlne, 535
Rio Tinto, $2$
Ardennes, method of mining fbic.
3'*
Arizona, copper in, 37
Armstrong's electric nignalling. iX-
Arrastra, 556, 61 8
Ananlt, free-falling tools, 129
on boring roda, 135
Areenio, preparation of, 6ig
flues, clothing worn vh^
clearing out, 673
Arsenical minerals, ^ects of ic-
haling dost from, 686
ores, cucination o^ 611, 613
mode of oocorrenoe, ai
sores, 686
Aiaenlous acid, piepAistion of, £17
Artificial ventilation, 49a
Amba Island, origin of phospbav
of lime at, 69
Aabestos, dresalDg of, 619
mode of oconrrence, 21
Ascensional theory of formation ::'
mineial veins, 15
Ascent, 536
Ashbomer on the ocoorrence •■'
natural gaa in the United Stattf
59
Aspen case, 9
Asphaline, 311
Asphalt, dressing of, 619
mode of occurrence, 22
rock, preparation for sale, 59^
AsBooiation of minerala, 97
Atkinson, Hessrs. L. fc C., on elec-
tric tiansmtsslon of pow^-, 172
Atlantic Copper Mine, Lake Se-
perior, 37
AUantic-Fnoiflc Tunnel, 437
Atlas powder, 314
Atmospheric weathering, 610
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AttacMog banliiig rope to banger,
Otto Byatem, 382
Attscbmentol rope to bucket, cage,
of wagons to endless rope,
368. 379
Anger, 113
' for boring holea for bkuling,
154
Btem, 139
Australia, candle-IioldeT used in,
trees nued for mining purposes.
228
Australian puddling tnActdne, 539
Austria, graphite in, 50
slldea for desoeni used in. 5x7
Automatic dumping cage. 419
stopping geu to prercnt over-
winding, 424
water taoE. Bowden's, 440
Galloway's, 438
Axles, attachment of. 357
lubrioatfon of, 358
Back ot lode, 106
Backstay, 366, 396
Bamiall's sleeper, 352
Bainbridge. Bmerson, on miners'
cottages, 677
on steel beams, 256
Baird's machine, 204
Baku, occnrrence of petroleam at,
Ballarat "indicators," 13, 16
Ball-grinders, 557
Ball-Norton magnetic separator,
603.606
Barber, mine, 639
Barracks for workmen, Kimberley
Diamond Uines, 676
Hausfeld, 674
Meohemich, 674
North Wales, 676
Barrow drill, 183
Barrte8,23
bleaching ot, 609
dressing of, 619
vein in Shropahire, 13
Bates, S39
Bath, workings for freestone, 310
lEX. ,17
Batb- Stone, 41
Bavaria, graphite In, 50
Baxter's stone breaker, 547
Bearer, 23T
Beanmonts tDnnelling machine,
206
Becker on inflammable gas in qniok-
siWer mines, 47S
on tbe Comstocfc lode, 76
on the interstitial apace in
sandstone, 18
on the qnloksilTor deposits of
Callforaia, 71, 73
on the quicksilver deposit* of
the Paci&c slope, 16
Bed ot PTiltes at Rammelsberg
Mine, Harts, 33
Bed-pisJikB, 405
Bed-rock, 318
Beds, 5
crumpliDK of, 88
faults and irregolaritles in, 88
occurrence ot zino-blende in, 87
recovery of faulted portion, 89
temporary pillars, 315
worked with permanent pilars,
309
Bedson on the fumes produced bj
coburite and tonite, 481
Bell-box, 131
Bellite, 31 <
Bellom oDlosa in dressing, 630
Bell pits, Ronmaida, 31 1
Belt, Bronton's endless. 585
Stein's endless, 586
Belts. pIcklDg, 541
Benchuig, 311
Bendigo gold-field, ^7
Benzine, in preparation ot ozokerite,
609
Bertrand Mill, work bj rolls at, 556
Bex, Switzerland, blower of marsh
gM.478
use ot bosseyease, 224
workings for salt, 307
Bilbao, iron ores ot, 102
Biram's anemometer, 507
BischoS, Mount, dressing tin ore at,
630
Bishop's head, 457
Bismnth ore, magnetic separator
used in dressing of. 606
BitnminoDS limestone, preparation
o'>S98
Vol de TntTers, 21
sandstone in California, 32
treatment of, 619
.vGooj^Ie
7i8 IND
Biwablk iron minM, discoTei; of,
BUckBtt level, HortbainbeTlMkI, 435
BUcUey, Rev. CaDOD, on old age
peonons, 694
Blake'B stone -breaker, 546
Blanchet, pnenmatlc hoisting appa-
Blani;, boring ram at, 1S7
Bltst, large, 390, 291
Blasting, acoidentB from. 706
explosiTsi naed for, zog
gHUM prodooed bj, 481
gelatine, 214
Enoi STStem. i6»
laying doit produced b;, 685 I
oU, 212 I
■afety fuse for, 217 I
tools for charging hnlei for, 160 ,
nnder wat«r, loses for, 317
with gunpowder, 317
with mtro-compoandii, aiS
Bleaching barjtes, 609
Blende, dressing of, 625, 630
ce of, 85
in of, from iron pTritei,
607
Blondin for raising stone from qnar-
Blonnt on Uqnid oarbonic aold in
minerals, 476
Btne-groand, 38
method of working, De Beers
mine, 341
Blnestone of Anglesey. 33
Boats, conveyance by, 372
Bochkoltz regenerator, 459
Bohemia, dressing of graphite in,
6»3
Boiler Eiplosion Acts, 666
explosions, 711
Bolsover collieries, miner's cottage,
677
Bonanta, definition of, 11
Booming. 293
Boots, 672
iTorn by rockmen, Pestlniog,
» ^"
Borax, 23
lake, California, 23
preparation of, 608
treatment of, in California, 620
Bord, 315 I
Bore-holei, conveying water to hot- '
torn of, 1S7
deviation of, 148
extraction of minerals by, 304
for' extracting salt, Hiddles-
brongh, 305
Bore-h<dea — eoHttnited. '
lining for, 131, 140
remodying tJevMtioii ot, 130
removal of debria from, iiS, i^i
141
snrveyiDg, 147
triaognliu', 159
Borers, 157
Boric acid, mode ot ocoDirence, 3j
prepuation of, 620
Boring, accidents to rods, &c., 130
asoenainlng dip and strike of
strata, 133
at Port ClaittKe, 137, 142
by American eyatnm, cost of
cro wn,Docwra s diamoiid settius
for, 1 18
doable-handed, 158
tree-falling tools, Amtnlt, 129
Sind, 130
hand-power di&moad. drills for.
123
band tools for, 154
head, Mather's, 145
holes for blasting, prerention of
dnst, 68;
holes of elongated aection, i6z
Mather and Piatt's system, 14;
method of sinking sfajafts, 271
Oeynhausen's sliding joint, 12S
pits for wire saw, 205
portable set of tools tor Iiand-
power, 117
process of, 12S
ram or bosseyeuse, 186
rods, iron, 125
■ingle- handed, 158
tools. 12;
nitb duunond drill, cost of. izx
with the diamond drill, itS
with wooden rods, 1 34
cost of. 136
speed of, 136
Boryslaw, dressing of ozokerite ai,
626
mode of ooonrrenoe of ozakerite
at, 64
safety ^ear for ttaaling men
S3'
sinking shafts with windlass.
38S
steel rings for eapporUng shaft
linings. 265
Bosseyeuse, 186
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Qfed for catting grooTe, 334
Bower's ooal- cutting machine, zo6
Bowie, Hydmnlio Mining, 393
Bowk, 408
Br^u'e hlftb tension fuse, 330
Bnndt's dilll, 178
Brattice, 4^;
Breaker, Butter's stone, 547
Blaie'e stoae, 546
Oates' ito&e, 560
Hall's atone, 547
Lester'B atone, 547
Hajsden's atone, 547
Breaking gronnd, 151
maobiiiee, uses of, 564
np minetalB, ^43
nse of boles fai, 107
Breast boards, 336
Brick linings for levBls, 351
for shafts, 251, 167
Bridgeiwla converted into sleepers,
Briagman'a ore-sampler, 635
Brine, eiraporation of, 609
Pamfdng Act, 666
wells, 30S
Briscale (Sldly), t03
Bmaob, 301
Broken Hill mines, 7S
cost of boring bj tbe diamond
drill at, 133
discoTeiy of, 96
lead poisoning among miners,
687
ontorop of lode, 98
square set timbering, 349
Brongh, on concrete linings for
■bafts, 354
on seorohlng for iron ore wilb
the magnetio needle, 113
Brown ooal bed at Brtthl, 5
Brnoaloni, 100
BHlokner furnace, 613
BrUhl, bed of brown coal at, 5
Brimton's endless belt, 585
furnace, S96, 613
sampling machine, 635
tanneller, 306
Boohanan, magnetic separator,
604
531
for boisting, 404
Bucking. 545
Baddies, 587
Bulkhead (bydnuilic mining], 195
8011,158
IX. 7i9
Bnllahdelah Uoonlain, N.S.W.,
olnnite at, 30
Ball engine, 4^3
BnlUon mine, beat at, 670
BoUook llanafaotoring Co., dia-
mond drills, 1 19
Boll-wheel, 139
Bnncb of ore, deflaltion of, 11
Banning, 330
BontonSi 337
Bnrckhajdt and Weiss air-com-
pressor, 166
Bormali, oil-Belds of, 65. 66
working without light In, 513
Bntterflf valve, 453
Oab Gooh Mine, Camarronshlie, 309
mode of working, 309
oocnrreiice of pyrites, S3
pnmping with compressed (dr,
471
Cue, advantages of winding men
in,6SS
darn Brea mine, 533
Comatock lode, 418
for descent and asoent, 533
Jonge hobe Birke mine, 533
selt-dumpiog, 419
Calamine deposit, Altenberg, 19, 87
pansy, 104
roasting si Uonteponi, 615
Calcarone, for snlphur rocli, 599
Calcination of arsenic ores, 61 1, 613
clay ironstone, 6it, 613
copper ores, 613, 613
gypsum, 611, 613
limesCone, 611, 613
ores, objects of, 611
tin ores, 613, 613
zinc ores, 6l3, 615
Caliche, 63
mode of working, 2S6
rnia, bituminous saodstona
borax deposits of. 33
drift mloing, 31S
Sold in, 45
jdntnlic mining in, 303
quicksilver deposits of, 73
treatment of bonu, 620
and Consolidated mines, beat
Gallon on working salt marls of
the Salikammeigut, 307
Oalnmet and Hecla Mine, 36
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Ctlnmet and Hecia
abaft timbering, 240
Btatupa at, 553
Canada, aabeatos In, 21
Dickel ore in, 61
CanadlMi system of boring, 134
Cancer of longs among miners, 6S6
Candle holders, 514, 515
□aed for tetUng qoaJlty of air.
501
Candles, speim and composite, 514
tallow, 513
Canton Mine, lode at, 8
Cap, in timbering, ais
OD flame of alcoDol lamp. 500
beotine lamp, 499
bj6.Kigoti lamp, 500
safety lamp, 499
CapeU faoi 495
Capping ropes, 403
Capstan for hoisting. 38S
for pmnpine; machinery, 461
Caratal Kold-flefd, 44
gold diggings, birds at, 105
Carbolinenm, 231
Carbonas, 84
Catbonic acid gas conveyed by
pipes, 374
mode of occurrence, 35
In air, an index of its imparity,
480
in the air of mines, 47s. 501
liqnefaction of, 600
preparation of, 620
testing for, 501
Cariboo, timbering levels, 333
Camidllte, occurrence of, 70
Cam Brea Mine, winding men, 533
Came, J., definition of a miDenil
Carrettand Marshall's machine, 199
Carriage of injured persons, 713
mineials by persons, 349, 375
Carritre. definition of, i
Can's disintegrators, 559
Cars, 355
Cartridges, hydraulic, zoS
lime, zoS
Cartridge- stick, 161
Casing boards, 23S
Cassiterile, minerals assooiated
Cast-iron colnmns nsed at HaUcyn
tnniiel, 2^5
lining for soft strata, 268
llnii^ for tnnnels, 263
props, 265
tobtiing, 269
Catchea, 460
CemeutAtion, 6t6
Cement works affected bv jTs
Acts. 665
Centrlfng^ aoaccBtn^tor, 591
grindsn,56i
Ceylon, diesaii^ of gi>pliit« in. '.:;
graphite In, 50
Chains, 401
Chamberlain, Hr. Joseph, on Sci
pensions, 694
Chance disooTeriea of miiienl li^
posits. 93
Changing hoose, 679
ChaunelUng machines, aoi
Chapeaa en fer, or gozzan, 100
Chapin Iron mine, Hicblgon, 54
Chuging-spoon, 161
Chase, magnetic sepatittor, 601
Chateangay Co., dresmng magnEtv-
614
Cheeks or walla of a lode, defioiL'c
jmnper nsed at, 157
saltmines, 311
salt wells, 306
Chesneau on testing for firedxcii
Soo
Chilian mill, 557
Chilled oaat-iroD shot, use of, (t
boring, 124
„. 484
China-claj. 37
discorery of, 99
dressing of, 62a
drying of, 592
workings In Cornwall, 292
Chlorate mixtores, 3 ■ i
Chocks or cribs, 345
Chollar-Fotosi mine, beat at. 670
Chromic iron in Kew Caledonia. 2S
Choms, Forest of Dean, 340
Chnrprinc mine, Freiberg, spherics
dam at, 432
works, loss at, 631
Chnteof ore, 11
Cinnabar, occnirenoeof, 71
Cironlar saw groove-cnttar^ aoi
used for slate, 564
Clack, 448, 453
■piece, 448
seat-piece, 44S
Clanny lamfi^ 519
Clarkson's rapid sampler, 634
Google
Clarkson - StanOeld conoetitntor,
59'
ClaaiifioatioD of dieesmg prooesses,
S38
mlneisl dapoBits, 5
rookB,3. 4
Clkj, 16
Clajing bar, 161
Clkj troiifltoiie, caloiiwtion of, 61 1,
treathering of, 611
CIajb, di«MiDg of, 630
Claj-sknt, 331
Cleaning- np, hjdraDlie mining, 299
Oleange of slate, SI
Glerelaiid, discoTory of salt bed at,
96
dlatriot, loyatUes In, 654
iron-mineg, jnmper need at, 157
ironstone, method of working,
« o(. si-
the origin of,
Sorb; 1
Clevis, 403
Clifton, testa of light glTon b;
Clanny lamp, jzo
Davy lamp, 5 19
Climax drill, 185
CUnograph, Hacgeorge'a, 147
Clinoatat or dlp-reoonleT, 147
Clogs, 673, 673
Clothing for men engaged near
maohinery, 673
of miner, 669
worn when cleaning arsenic
fiues, 673
Clowee hTdrogen lamp, 500
Clab, deanctioDS for aoddent, 639
Coal, discovery of, in sonth-east of
England, 97
Coal Hines Regulation Act, €63
accident staUstfcs nndar, 700
tools for ehaiglug holee, 161
Cobalt mines, Buony, canoer of
Inngs among mbieTB, 686
ore in FlintaUre, diacoTery of,
93
New Caledonia, z8
Rhyl, Flintshire, x»
Sknttwiid, Norway, 37
Cobbing, 544
Cofferi^, 267
Cold at minee, 669
CoUe Crooe mines, Laroan, BfoUy,
tlilok snlphnT seam, 311
ColUeriM affected by Alkali Acts,
665
\SX.. 731
OolUns on the china day ot Corn-
wall, 37
on the Great Uother Lode of
OaUfomla, 46
on the ores of Rio Tlnto, 33
on the pyrites deposits of
Hoelva, 32
Collon jigs, 631
Colorado, lead ores of, 57
lease system, 647
sampling macluDet nsed In. 634
tribote Bystem ie, 647
ColoiadoB, 100
Colour as an aid to ttie prospector,
99
Comparatire mortality figores, 683,
684
Componnd for native miners, Kim-
berley, 677
engines for pumping, 443
Compressad air cartndge^ 2ce
looomotives, 363
loss of power from ose of, 164
pipes, 170
pumping with, 470, 471
reservoir 169
sinking by M of, 377
stamps, 551
use for ventilating workiogi,
493
C'OmpresBOrs, air, 164
Comstook lode, description of, 76
discovery of, gs
gases met with, 476
lifting pun
shaft tinib
p nsed on, 449
shaft tfmbering, 238
square-set system of timbering,
timbering for levels, 333
Conoentrator, centrifugal, 591
Clarkson and Stanfleld, 591
Embrey, 586
Woodbury, 5S6
Concrete blocb, 153
Qsed for lining levels, 351
shafts, 3J3
Condition of miner, 669
Congenial beds, 13
Conglomerate, oopper-beariog, 35
Conical grinders, 560
Cookllng magnetic separator, 601
Oonvolvnlns althwoides, tc^
Cook's Kitchen mine, beat at, 670
Co-opeiative pumping, 474
*ooletiM,696
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Mlntlon, 307
of. 616
r AlkkU Acts,
OKlcUwtioD of, 6t3, 61]
dresdng of, 611
in a«rmaD7, 39
In Spain uid Portugal, 31,
in the United Btatea, 34, 37
oocairence of, aS
Mpamtloa from tin ore, 609
Coref, uoertainliig dip from, 133
ontting oat, 1 33
axtnwMir, 119
ArsbIVi, 133
Bollock's improved, iii
modes of obtaining, 1 32
obtained by boring witb flat
rope, 147
produced in boriog pits, 305
tnbe for diamond drill, 1 19
Oorf, derivBtion of term, 405
Cornish " dry " for china clay. 593
miner's boot, 671
hat, 671
pnmping engine, 443
rolls, SS3
Cornwall, annual death-rate of
miners, 6S4
oonuty adit, 308
dressing of tin o
mode of oconrrenoe of tin In,
7. >?. 84
royalues in, 654
tin lodes of, 7
Corrosive water, pumps for, 450
valves tor, 453
Cost of aerial ropeway, 385
ontisepl.ia treatment of Umber.
331
barracks for workmen, 676
coffering shaft, 368
co-operative pumplDg, 474
cottagas, 677
driving level at Bex, 234
electric haalage, 173
lodgingE, &c., for workmen,
Eisleben, 676
sinking thiongh watery strata,
271
■teei snpports for levels, 356,
worldng Eold- bearing gisvcJ,
California, 330
Coantarbalandiig weight of pomp-
rods, 457
rope in winding, 393
CoBDterpoiM for r»ds, variable,
460
Country, definition of term, 10
infloenoe of, on lode, 12
County adit, Cornwall, 435
Course of ore. definition of, 1 1
Cox, S. H., on an alnnite deposit in
M.S.W., 30
on the cokinr of regetation. 104
Creep, 309
Crib, or curb, 353
CroBs-courae, or fault, 91
Crow's-foot, 130
Crump and Brereton'e rnachine,
Cornish, 553
Dodge, S47
Dates, 560
ahing in of working*. Sicilian
suiphar mines, 321
CryaUlline Bchista, 3
Crystallisation, boiai, 60S
nitrate of soda, 60S
potosslam salts, 60S
magnesium ctiioride, 609
Candill, on explosives, 209
Curb, cast-iron, 367. 370
Cnveliei's look for safety lamps,
522
Cyclone pnlveriser, 563
Dam, temporary, 433
Dams, masonry, 433
spherical woodeo, 431
wooden, 43a
Darkness, working in, 513
Darlay, on boriug by rotation, ity
Darlin^n drill, 195
Danbree on the artificial f ormatioD
of minerals, 1 7
Dauntless diamond drill, 119
Davey's differential pnmping en-
gine, 445, 466
Davis' self-tiiWDg anemometer. 507
navy lamp, 619
Day Dawn mine, pigsty timl>snng,
MS
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Dbj Dawn mine — coKtintied.
shaft timberii^. 239
tfmbeiiiig, 234
Day-level, 433
Dnli^ht, working by reaeoted, in
Caliloniia and Japan, 513
Death-rate of miners from acci-
dents, 698
Death-rateE, annnal, for variooB
tradee, 6S4
De BeeiB diamond mine, 38
endless rope haulage at snrfaoe,
376
head-gean, 397
mathod of working, 341
self -discharging ^ps, 412,
wBshmg machine, 540
Deep leads of Australia, 85
DeSection magnetic separator, 606
Deposition from solation, formation
of veiDS by, 14
Derbyshire, Mining Acts relattog to,
with rope, 137 '
Descent and ascent of miners, 526
DeBiccation in dressing, 592
Detaching hooks, 422
Detonators, 216
strength of, 219
Devonshire, dressing of olay, 620
mangnsese ore, 635
umber, 626
Diamond, substitutes for, for drill-
ing, 124
Diamood- bearing rock, De Beers,
diessLDg of, 62 1
method of working, 341
weathering of. 61a
DiamoDd, discover; of, in South
Africa, 93
occurrence of, 37
washing machine for, 539
Diamond drill, American Diamond
Rock Boring Company's, 121
boring at Johannesburg, 119
Northampton, iiS
boring with the, 118
Bnllook Manufacturing Com-
pany's. 119, 123
Bullock's improved, 1
cost of traring by, 122
crown, 118
•' Danntlesi," 119
difierential feed gear, i ig
KX. 723
Diamond drill — continued.
for boriiig holes for blasting,
179, 180
Qeorgi's electric, 124
Little Champion, 123
prospecting. 123
sediment tube for, 119
Sullivan's prospecting, 124
Swedish for huid-powcr, 123
thrast register, 121
Victorian "Giant Drill." 121
Dickinson's anemometer, 507
water-gaage, 509
Diepenlinchen, pamping engine at,
345
445
working zmc
zinc ore stockwork, 87
Diffusion of gases, 485
Dig, definition of, 1 1
Ding Dong mine, fire-damp
h 477 .
Dipping needle, 11 1
Discovery of minerals, 93
Diseases caused by arsenical mine-
rals, 6S7
inhalation of duet, 685
ladder climbing, 688
lead ores, 6S7
quicksilver ores, 6S7
Disintegrators, 559
Distillation, of rich sulphur iock.600
use In dressing, 600
Dividings, 237
Divining rod, 11 1
Doctor, deduction for, G39
Docwra, dimnond setting for boring
, 5i5
: of wor^ng.
heat at. 670
Dolly, or ^juaiie, iSi
Dolly tub, or keeve, 570
Dorothea mine, Claosthal, nnder-
pround traffic by boats, 373
Double-beit valve, 454
Douglas spruce, 228
Downcast shaft, 4S4
Downthrow, 91
Dowsing rod, iii
Drainage, 439
by adit. 433
by pnmps, 441
by siphon, 437
by winding maohinery, 437
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grab, 1
isosid fe Mcgneen'B, 175
Prie«tiaan'» grab, 176
•OCtlOD. 177
DtMring. deaDltioD of, 537
•nenlo or«, 619
ubeatot, 619
Mi^ialt, 619
barjMa, 619
MiaminoDB rock. 598, 619
blwde. 625, 6]o
bom,6ao
borio Mid, 6>o
oaitxMiio acid. 630
obeTt,633
china claj, 630
cla;>, 630
ooppar ore, 6zi
diamond -buulDg rook, 611
flint, Gza, 629
foUei'R euth, 610
KBl«na,6i4, toj
gold oM, 631
graphite, 6a3
K7pinm,6z4
hiuiuitite, 624
iron ore, 6x4
lead ore, 624
magnetite {ite magoetto sepi
TAton), 624
mai^ianete ore, 615
mica, 62s
miafdckel, 611, 612, 613, 619
octue, 636
oiokerite, 626
phospbftte of liioe, 626, 627
potassiom salts, 627
quicksilvor ore, 627
salt, 61S
sUver ore, 62S
slate, 62S
Btotie, 618
snlphnr rock, 629
Trinidad pitcb, 619
tin ore, 629
nmber, 626
lino ore, 625, 630
Drill, ratchet, 155
Drilling rig, 13S
tools, 139
DrillB, Adelaide, 195
aatomatia Totation of, 194
Barrow, 183
Brandt's, 178
olauifloation of, 183
Drills — txmthaied.
CUmaz, 185
Dkrlington, 195
diamond, 179
ScUpae. 187, iSS
electric psnnunon, 19^
Elliott. 154. IS5
for boriDg by hand, 15;
Fnnke, 189
HiTDMit, 193
IngeraoU-Bergeaat, 193
Jarolimek, 179
Harvm. 198
Optimns, 1S9
peroDseiTe^ 181
rotary. 177
"93
sbaipouiDg, i^
Stearanaon, l)
eteelfor. iSa
i,iSi
Driiing lerela, 22t
tunnels In soft gTODid %j
DnuDs for winding, 391
with reMTTe of rope, 391
D17 oompresaora^ 166
for China olay, 591
or changii^ honse, 679
rot, prevention of, tp
Drying (rf minerals. 591
Dnbois and F1M190IS air-compe*
166
boring-ram, 186
Dock macoine, 493 ,
Dncktown mine, Tenneaeeft i»
blower ot Bolphoretudiiri^-
Dudley, workinga for JimeWW'?'
Dnmb fanlt, 87
Dnnbarand Roston's »W«i»^
Dnstin mines, evUeffecUonUii^
6S5
in air of mines, 4^2
Dnty of the miner's inob, p^
of pnmpng-engines, 47^
Dykes, definition of, 14
I^namite, 213 _
danarer from exadstx*, 11 j
pan for thawing wtoi ft««'
Eadir ft SoHB', joint for lip"***
jdpes, 171
1 EolIpM drill, iSS
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second magnetic separator, 6o3
Education Act^, ElemeDtarr, 666
general and tccbnictkl, 68z
BfficiGQcy of ventilating appliances,
S09
UiiilebeD, barracks for workmen,
674
Electric drill, Uarvia, 198
SteavausoD, 180
lamp, SassmaDD, 523
light, 514
percussioQ drill, tgS
railways, 371
Electricity, tiring by, 330
pumja worked by, 470
transmisBioo of power by, 172
Biement>iry Edacation Acta, 666
Elephant atamps, 551
Blliot'a looked coll wire rope, 400
Elliott drill, IS5
multiple wedge, 208
Elwen on the reaistance to afr-
ourrents, 51 1
Embiey concentrator, 586
Emmons, S. T., on tlie geology of
the LcBdville dittrict, 57
on the veins In the itooky
Mountain region, 7
Broployers' Liability Act, 666
Bma, loss in dressing at, 631
End, ventilation of an, 485 , 4S7, 493,
493.
37'
rope ayatem of Jianlage, 367
advantages of, 369
attachment of waggons to,
368. 379
De Beers mine, 378
End-piece, 137
Eqailibiiam pipe, 274
Erigonnm ovalifolinm, 104
Broat Angnst StoUn, 434
Eooalyptus, species used for mining
purposes, 229
Eureka, Nevada, silver-lead deposits
of, 77
sqoare-set timbering, 347
Europv. trees need for mining por-
Enstice, changing bouse at Levant
Mine, Cornwall, 679
Evans and Veitcb, pnmp for raising
water by comprmsed aii, 471
Evaporation of brine, 609
7^5
Excavating by water, 3x6
machinery, 173
Excavation ot minerals nndergtound,
308
onder water, 303
BzcavatioQt, sapporting, 337
Exploitation, 285
Explosions of fire-damp, 476, 477
E^louves, accidents bom, 707
strength of, zi6
used in mining, 209
Exploaives Act, 666
Extraotion of minerals by wells and
boreholea, 304
Falls of groiiDd, accidents from, 704
Falon, torches aaed at, 51J
i'ana, Capell, 495
efficiency of, 509
Gnibal, 496
Schiele, 497
nse of, In dressing, 590
Waddle, 497
Faults, 87
length of, 90
measurement of throw of, 89
recovery of lost part of bed, S9
recovery of lost part of lode or
'I'ariBtiona of throw along the
strike, 90
Feeders or ilroppers, definition of,
Fencing Act, Qoairy, 667
Fend-off bob, 446
Fernow on the trees available tor
mining purposes in the United
States, 3zS
Festioicg, boot worn by rockmao,
673
method of working slate at, 313
preparation of sla«e at, 638
slate mines, charging spoon
used at, 16 1
drlvages at, 333
jumper nsed at, 157
tribute system at, 649, 651
Field, Ur. Justice, on the Ri<^mond
V. Eureka case, 8
Filling up, working with complete,
3w.331.335. 34". 343. 346
Fir, ijcotch, 338
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736 IMl
Fire-olay, 36
wsaljieriiift of, 61 1
inifr4atQp foamd in ore miaeB, 476
testing for, 49S-501
Firaleu locomotJTet, 363
Tirei, MWideats tram aadargrouiicl ,
708.709
In sulphur mines, Sicily, 331
Fire-settinfr, 335
Firing by Sectricitj, 330
exploslveB, 218
Firth's pick niMliiDe, 199
Ffauelunp, 516
FUt-rope, winding with the, 393
Flattened stnuul wire rope, 400
Flint, dressing of, 632
mining at Brandon, Suffolk, 41
Ftinta, ehapli^ of, 629
Floating reef in Simberley dia-
mond mines, 3S
flooded workings, breaking Into, 707
Flookan, eiplsnatlon of term, [4
Floor of a bed, deAnltion of, 5
of changing hoase, 63i
Florida, phosphates of, 69
Flume, 294
Fluted rolls, 556
Foot-wall, deHnition of, 10
Forest of Dean, method of woAing
htamatite masses, 340
Uining Acts relating to, 655
Form for pump bncket, 44S
Form of the groand indicating de-
posits, 98
Formation of mineral veins, 14
Fonnations or olasses of lodes, 17
Foidale lead mine, carbonic acid
strike of lode, 14
Frames, 579
for levels, steel, 360
wood. 333
for shafts, 336
Frauoe, vndergtonnd workings for
slate, 314
Franke drill. 189
Franke's meohanioal chisel, 199
Free-falling tools, Arraalt, 139
Kind, 130
Free-milling ores, lol
Freestone, 41
mode of working, 310
Freeiing method of sinking shafts,
37S
Freiberg, formations of lodes at, 17
French miner's hat, 67 1
Friability, nse of tn dressing, 607
Friotiondue to sides of airwa7, 510
Frongoch ligger, 573
■eU-dischai^ing skip, ^^i
separator, 576
Froien dynainite, 213
Fme Tanner, 5S5
for gold ores, 632
Fuller's earth, 27
dressing of, 620
Fnmaoe, Brtmtons, 590^ 613
toasUng, 61 1
ventJlation, 490
FuiiMss district, tempMsij 6c
uBedin,4:j3
Fosa, electnc, 230
for blasting purposes, a 17
for simultMieous blasting, u:
Gad, 154
Qalena, dtcesing of, 634, 015
GaUoiB, Canadian eyBlein of bcoif ,
1D.J34
osokerite mirtes of, 63
.owaj on the fire-d^
Galloway's antomatio
438
double walling stage. 4°9 ,
method of guiding kibUft f
pneumatio water-band. 43°
•teel tram, 359
winding drain, 393
Garfield Mine, Califoniia, 79
Garland, 267
Oamier, disooverj of nicksl ow »
New Caledonia, 99
Gas for nndei^round lighting S':
Oases produced by deeompoaW
of gon-oottan, 315
8,311
izplodon of gnnpowder, no
btasti>)g,48i
Gates crasher, 560 „
Gtltiscbmann, on -ti'*"^'" ** '"^
tors, lo;
Gearing pomp-bnokets, 44^ . ,
Oeikie, Sir A., definition ofa>iiiW»
vein, 6
Gelatine dynamite, 214
Gelignite, 314
Geology as a guids to min«w^97
German miner's hat.
deatJi-rate from ac'oidentB, iW
Iaw of Insurance, 694
occurrence of tino ore in. >7
■,Goo»^Ie
OeroIsteiDiboriDgaforcarboniaaold .
gas at, 15
Oiant granite, 58
m&ee, 390 I
powder, 214 '
OUIott and Copley's macbine, 103
Gill's f nrnaoe tor snlpbur eitiaclioD, 1
600
Oitlieiu BjBtem of borioK, 161
Gobert's modification of Poetsch'i
(reeling prooeBs, 2S3
Gold, amalgamation of, 616
associated minerals, 97
modes of , .
ores, treatment of, 6x3
Run Ditch and Mining Co., 302
worked in Alps bj Bomana, 61&
Gold-bearing giavel, method of
mining in Cnlifoniia, 31S
prospecting for in Siberia, 37S
working, 293
yield of, 303
Good conduct, preminma for, 65a
Gooseneck, 403
Gouge, definition of, 1 1
Gozzan, 99
at the Anaconda mine, 37
at Rio Tinto, 33
influence of, on value of ore, lot
Graphite, 50
dressing of, 623
in Bavaria, 607
Gravitation stamps, 548
Great Basin, borax deposits of tbe,
*3
Greathead shield, 263
Great Laxey Mine, locomotive, 363
overshot wheel, 442
Gieat Quaitz Vein of Califoniia,
length of, 1 1
outcrop of, 99
Great Western qnickatli
California, 74
outcrop of lode, 9E
Greaves' ciroolar
machine, 565
Grey box, 229
Gciteth, on coffering, 268
dime's graves or ancient workings
for flint, 41
Gnmm, definition of a mineral vein,
Grinders, Gmsonwerk b
ball, 557
centrifngal, 561
conical, 56a
Jordan's, 557
Se* ako under Caua
I. SS7
EX. 727
Oriszly, 399
Groove-onttaia, 201
Groove-cutting maohines, 199
GroovM out by circnlar saw, 202
traTeUiog rock drill or jumper,
made by endless ohain with
outten, 304
revolving bat with cutters, 106
vrire saw, 304
Grosonwark ball grinder, 557
Qndgeon, 457
Guibal fan, 496
Guides for shafts, 40S
Guillotine slate-dressing machine,
565
Guinotte, pumping-engines with fly-
wheel, 444
Gun for cleariiig bore-holes, itio
Gun-ootton, 21 j
products of decomposition, 212,
3(5
Gunpowder, 309
charging holes with, 217
products of explosion (^, 210
Gunpowder Act, Slate Mines, 659
Gntta-peieha packing for pump.
Oympie gold-lieid, lodes of, 13
Gypsum, 50
calcination of, 611, 613
discovery of, by sub-wealden
boring, near Battle, 96
dressing of, 624
occurrence of, 50
qoairiss, Paris, 309
Haabe process of sinklDK sbafis, 383
Habeta on annual deaui-iate bom
aooldents, 699
Hade, definition of, 9
Hsanatite at Iron Mountain, Hiob-
Igan, 54
deposits of the Ulveiston dis-
trict, 19
dressing of, 624
method of working, 340* 343
■earching for by piercing. 106
veins of tbe Lake Dustrict,
Kendall on, 7
Haenser process for slnkiog In
quicksand, 184
Haggle's patent Protector lope, 400
H^e's mouth valve, 453
Hale and Noicross mine, beat at,
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;.8
Hkll'i stoiM-braKksr, 547
Uaminar, of Mmiufdd, on lifting
bwn of pnmplng angiDB,
461
OD the frlotion of guiit '"
ir boring bj hand, 159
Huarto'i aJi-oompreMor, 165
Hand-buTOws, 375
Baud-drUUiig, 157, 160
Hand-i^ofciiia, 541
Huid-power dlUDOud drill, 115
nrturdrilU, 155
HAiid'ivnpUiigT 632
Hsnd-daTw, 566
Hand-tooli, 151
Hug-Bie, 317
Hanging wall, deflnitloD of, 10
Haoial and Lneg'i kepa, 419
H&rtlng and Hesw, on oancer of
Inngi oaoied by dnst, 6S6
Harti blower, 493
jff. 570
minv't lamp, 51 j
UmbnlDg cbamber for irat<
wheel, 241
Umbering for Bhaft, 340
nie of water power, 441
Harvey on the occurrence of i
trate of soda in Chill, 61
Hat, Comiib miner's, 671
Frenoh Duner's, 671
German mlnar'a, 672
ideal miner's, 67a
lioDfltone miner's, 671
Uanifeld ininer's, 673
Ronmanlan miiicr'i<, 672
BatoheB, 3S9
Haalage.348
electric lailwajs, 371
eodleia ctiain, 371, 379
endleu rope, 367
hortea, 362
looomotive, 363
main and tail rope, 366
single-rope ijstem, 365
Head-gear, 394
He«t at minei, 670
of mines on Conutock Lode, 76
of workings, inflnenca on
bealtfa,689
Heued floor*, AijioK on, 593
Hean.88
of Teln ridewKya canaed by
slip along tine of dip, 91
Heavy apar, bleaclimg of, 609
ooomrenoe, f\
Heights (N- I«aoaBbir«), 344
Hepplewhlt«-Giay lamp^ 521
Hercnlea powder, 214
HoBse's method of testing the air,
S°3. SOS
Hlmmelfahrt works, loaa at, 630
Htmant drill, 192
Hirt, on prevention of lUneas Itoffl
areaiio,686
Hltohes, 154, 331
HoDkin and Osland calciner, 613,
61s
Hoffrnan maguetlo aspaiator, 602
Hofmatiu kiln, 613
Hoisting, 387
Holes, arrangement of, for driving
and sinking, 233, 335
Holway Consols mine, explosion of
fire-damp, 476
UoDlgmaun, suda locomotive, 364
Honningen, carbonic acid gas at, 35
Hopper of hydraulic elevator, 300
Hoppet, 40S
Homed sets, 333
Horse In lode, definition of, 1 1
-whim, 389
Horses, nndei^ronnd haalage by,
363
Hosfdtals, 695
Hot springs, 476
Hottiogner shaft, Blanohet's pneu-
matic boist at, 438
Honsa, changing, 679
Housing of worEmen, 673
Howara'a ^eel sleeper, 353
Howell's steel tube prop, 266
H -piece, 451
Hnanchaca silver mines, 78
Hnelva, port of, 380
Hnnd, 351
Huntington milt, 561
Hnnioane lamp, 516
Hurry, 344
Husband's stamps, 551
Hnshinff, 106
HvdraiJio cartridge, 208
drill, i3o
elevator, 300
look for safety lamps, 522
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Hjdranlio — eonlinvtd.
mining, 316, 393
for breaking groand, 163
Idria, occuirence of qnlcknIlTeE ore
at, 7a
treumeDl of golokBilvet ores.
portable, 523
Indin&tioti of a lerel, effect of, on
TentilatioQ, 4S5
of nndergiound road, 355
iDcUue, natural ventilation of, 4S6
Inclined planea, Mjcidenta on, 708
nndei^Tonnd, 363
shafts Bonk on lode, 125
Inclines, 30S
self- acting, 37G
Indicatioos of tire-damp, 498
Indicative plants, 103
Indicator for winding engines. 421
Indicators at Ballarac, 13, 16
InSammable gas, 59, 476
Ingereoll bai-channeller, zoi
'Sergeant air-oompressoi, 167
Injection compreesors, 166
Intersection of veins, t ■
Inversion of strata, SS
Inverted laddle-reets of Victoria,
Iron and steel supports for levels,
shafts, 363
workii^ places, 265
Iron-bark, 239
Iron liat, or gozzan, 100
Iron ladders, 529
Iron mines, ^oreat of Dean, method
of working, 340
N. Lanoashiie, method of work-
ing, 343
Iron ores, aressing of, 624
occurrence of, 51
NortharaptoDsblre open work-
ings, 286
Iron pnmp-rods, Shakemantle mine,
461
Iron pjrita, Carnarvonshire, 83
Iron ridls nsed for supporting roof
of level, 256, 259
Iron rings for tappoTting shaft
linlDgH, 363
Iron rods for boring, 134
Ironstona blows (Australia), 100
IroDStone, meliiod of working In
Cleveland district, 315
miner's oap, 67 1
Irruptions of wnter into mines, 707
Irving on the oopper veins of Lake
Saperior, 36
Itat^te, 40
Ital}', alabaster in, 51
asbestos mines of, ai
boric acid in, 25
carbonic acid gas In, 26
marble in, 58
mining law in, t, 3
mode of oconnence of eolpbDT
In, 82, 83
Jack, on the Mount Morgan gold
deposits, 48
aa the outcrop of gold velnB In
Qneensland, 98
Jscobi's stove, 597
JacomMy and Lenlcqae's Bspon-
tors,S7S
table, 5S3
trommel, 567
Jacotinga, 44
Jad,3lo
Jsf^ersfonteln diamond mines, 39
Jan Ham's clack, 4(3
Japan, torches usea In, 515
working by reflected daylight
in,5i3
Jarolimeks drill, 179
Janah, 238
Jars, 140
Jaw-breakers, 546
Jigger, 570
pneoioatic, 589
Jiggers, dlschu^e of, 573
Jog, 237
Jotuumeabarg, deep boring at, i ig
Joint for wooden rods, 445
Jordan's grinder, 557
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I EreiMiIier and Winkler on the tp-
I pearaDce of the fin-damp cnp, 499
I Krom rolli, 554
I Kiom'B store, 595
434
Kaiser Josef II. adit, Pribram. 434
Kauri gum, searching for bj
pieroiDg, 106
pine, 330
Reeve, or doUy-tnb, 570
Eend«U od the geoli^ of the Cleve-
land district, 41
on the htematiu veitw of the
I^eDlstTiot, 7
Kennedy on the efficiency of com-
pressed ftlr, 164
KepB,4i9
Eesgler, magnetic separator, tea
Kibble, 404
Kieselgahr, 313
Kiln, American phosphate, 594
fuller's earth, 595
Hofmann, 613
Kilns for drying, 594
Kimberley diamond dlsUiot, 37
mines, componnd for native
workmen, 677
method of « orldng at De Beers,
Kinc^d and MoQneen'e bncket
dredger, 17s
Kind, fiee-faUing tool for boring,
130
-Cbaudron process of staking
recent modifications, 376
King and Bumble's detaching hook,
King,onthe "indicators" at Ballarat,
on toe Comstock Lode, 76
King-post, 457
King's magnetic separator, 604,
606
Kitto, Panl and Nancarrofr, self-
dischargine skip, 416
Knots in the lead-bearing sand-
stone at Uechemlcb, 55
Knox tystetn of boring holes for
rending stone, i6z
of charging boles, 330
Eongsberg silver mine, flre-settitig,
325
Laboub, principles of employment
of win log, 637
Laddor-^Jimbiiw, diaeases cansed bj
excessive, 688
Ladders, 527
Iron, 539
Lagging,
L^dlei's
"33
idlers sector wire rope, 401
Lake Sapeilor, copper-bearing dis-
trict of, 34
Inm ores of, 54
mines, stamps nsed at, 551, 553
treatment of copper ore at, tai
La Lonvi^re mine. Belgium, 467
Lamm and Franck'sflrelese locomo-
tive, 363
Lamp, electric, 533
flare, 516
Harts foreman's, 516
Uartt miner's, 515
Horrlcane, 516
magnesiam ribboD, 517
Hansfeld, 516
safety, 518
Baiou miner's, 516
Scotch, 516
aolllaD. 515
Unit«d StAtcfl, 516
Lander, 410
Lang's wire rope, 400
Larch for timbering excavations, 11;
Lashings, 237
Latch and Batchelor's flattened
strsnd wire rope, 400
Lateral secretion theory ot forma-
tion of mineral veins, 1 5
Laths, 343
lAwn, on searching for hematite
in the Fumess district, 106
on working hnmatite in North
Lancaslure, 343
Laxay mine, locomotive at, 363
man-engine at, 535
strike 01 lode at, 14
Lead lode at Wheal Uary Ann, 6
ores, dressing of, 634
modes of occnrrenoe, 55
state of In gouan, 101
plant, 104
poisoning, 6S7
preTenUon of, 6S7
rivet for safety lamps, 533
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Lead-bearittg ModEtone, Hocber-
niob, iS
Lead, mode of working, 330
Leadrille, Colomdo, mode of occur-
rence of lead orea at, 55, 57
Lease Bystem fn ColoraiM, &17
Leather packing for pomp*, 44S
LeBts,393
Leavitt stomp, 553
Legal definition of the term lode, 8
Legislation aCectiug mines and
qoanies, 65 3
Leg, or side-prop, 831
L^rand'a steel sleeper, 352
Lenoescbiefer, LOderiob mine, 85
Lesley on the composition of natural
gas. 59
Lester a stone- bnoker, u.7
Lefant Mine, chMi^g house at, 679
Lerel, natnral ventilation of end til,
48s
use of air-soUar In ventilating
Levels, driving, zsz
iron andeteelsuppoTtsfor, 255-
lined with masomy, 150
methods of timbering, 233
Ten tilatine lower, 4S9
Liahilit? Act, Employers', 66ft
Ltd, 244
Li^vtn Companj, shaft sank by, 177
Lifts (Cleveland), 316
Lighting norkings, 513
Lime cartridge, zoS
Limestone, bttaminons, Val de
Trafera,2i
bnming of. 611, 613
Lime-water test for the air of mines,
501, S03
Lindemann'K apparatns, 506
Lining boards, 44;
bore-holes, 131
tnbe, boring by rerolving the,
"7
tnbe for brine well, 305
Linkenbaeh, stationaty table of, 581
Liquefaction of oarbonic add, 600
use of, in dressing, 597
Listings, 237
Litbouacteur, 214
Liveing'e indicator for Hre-damp,
antomatio
,,5«?
LUnbradach CoUiery,
water-tank at, 437
sinking arrangements at, 408
stoel trams at, 359
Loading kibble, 405
skip in shaft, 410, 412
731
„ (AoBtraUa), 106
Lochs, definition of, 6
Locked ooil «ira rope, 382, 400
socket for, 403
Lookhart'B gem bepantpr, 577
Locks for safety lamps, $23
Locomotives for nndergroond nse,
363
for nse at the surface, .',78
Lode at Wheal Hary Ann, 6
definitions of, 5, 6
legal definition of, 9
modes of working, 325, 340
narrow, mode of working, 330
wide, with weak sides, mode of
working, 331
worked away in slices parallel
to dip, 335
Lode-lights, 107
Lodes, conditions aSeoting prodnc-
Uvenessof, 11
length of, along atrike, 1 1
formed by alteration of the en-
closing rock, 7
wide, worked with pillars and
chambers, 338
Lofting, 256
Loogwall workings for copper -shale
% Mansfeld, 322
id, sapp
_ in, 242
timbering levels in, 336
Lomdne, iron ores of, 53
Loss In drea^g at Cbarprini works,
631
at Bms, 631
at Himmelfabrt works, 630
at Feetarena. 631
cania ot 630
slate, 631
Lovett-Finney magnetic sepanttor,
603
Lowmoor jacket, 713
Labrication of mine wa
Luderich lino mine, 85
Lnnge's apparatus for testing the
air of mines, 503, 505
Uagoboboe on deviation of bote-
boles, 14S
Machine drills, 181
slevea, 566
Machinery, aooldents from, 711
olothiiig for men ei^aged near,
673
Hagueslnm ribbon lamp, 517
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Ub^«Uo lock for ufM; lunps, 521 1
sepai&ttoti, 6ao I
biBmnth ore with magnet- '
it«,6o6
Naiiuuiu& Coppei Co., 606
objects of, 600
QoeenslAnd, 606
separators, 600
Bkll -Norton, 603, 606
Buchanan, 604
Chase, 601
Gonkling, 601
Edison, deflection, 606
wcond, 602
Hoffman, 60a
Keasler, 603
King, 604, 606
Lorett-Flnney, 603
Wenstrom, 605
Magnetite, dressing of, 600
jiggiDg, 614
Main and tail rope syatem ot haul' i
a(te,366 |
Hajendie, Colonel, dd the effect of ,
oil on ^ecj fuse, 317 I
Malay Peoiamla, tin-lWring aUnvia
of, 85
Mallard and Le Chatelier on testizig |
for flre-damp, 500 1
Mallet, oc sledge, 154, 159 j
Man-engine, 534 |
accidents on, 705
Manganese ore, dressing o^ 625
occurrence of, 57
Manafeld oopper-mioes, 29
edit at, 434
barracks for workmen, 674
compound pumping engine,
Kmst IV. nb&ft, 443
compouod pumping engine.
Otto IV. shaft, 444
cross-cot lined with
descent and ascent of
employ^i liviog id on
679
hydraulic oonnterpoise to pump
rods, 45S
lamp used at. 516
maa-engine at, 536
method of woiking copper-
shale, 322, 325
miner's Mt, 672
pick used at, 1 53
Kitlinger pump at, 456
thickoesB of bed of copper-
treatment of copper ore at,
621
n booses,
169
ondergronnd pumping <
Marble. ^8
MaroB-UJTar, arc-lamp at, 524
Marsaat lamp, 521
Maisdeo's pulveriser, 547
stone-breaker. 547
Man hall, discovery of gold in
California b;, 94
Marsh-gas, found in mines, 476
Maraton Hall mine, 311
Marvin dilU, 19S
Masonry, for lining levels, 249
dam in shafts, 433
Masses, or non-tabolar deposits of
minerals, iS
methods of working, 340
Matai nood, 229
Mather and Piatt's system of boring,
142
Matbet, joint for air-mains, 170
Matrix, defjuitioii of, 11
Haul, 141
Measure, payment by, 638, 639, 640
and time, payment by. 641
Measuring the quantity and press-
ure of etr in mines, 506, 513
Heat eartb, 286
Mechanical picks. 199
processes of dressing, 538
ventilation, 491
Mcchemicb, arc-lamp at, 524
barracks for miners, 674
dressing lead ore at, 625
friability ot ore, 607
55
method of norking lead-bearing
sandstone, 320
opencast, 2S9
pumping engines at. 467
siphon sepaiator used at, 579
Medical attendance, dedaction for,
639
Medium fan, 49S
Mercurial polsoniDg, symptome of,
6SS
vapour in qnicksilvec mines,
480
M^tsJes fiioa, or unchanged sul-
phides, 101
Metallic saf^OTts for excavations.
.vGooglf
Uetalliferoas Hinea BetnilatioD Acts,
656
accident sUtiitici, 700, 701
Uica, dreodng of, 635
mode of occntreDoe of, 58
HiddleabTOQgh, estnction of salt
bj bore-holes, 305
msnh-gas with brine, 476
mU, Cbilian, 557
HnntingtoD, 561
StnrtevaDt, 563 '
Close lead miDe, Derbystiiie,
ezplosion of flre-damp, 476
UillB for griading, 556
or panel, 330
Mine, atmotpbere of, 475
deflnltiOD of, 1
derivation of word, i
Miner, clothing of, 669
conditioD of, 669
regnlations for benefit of, 655
Hioera zino mine, Wreibam, 8<3
Mineral deposit!, classification of, 3
repositories, anomalies in. 17
vein*, oonneotion of, with f aolta,
89
formation of, 14
Minerals, ownership of, 653
Hinero bird at Caratal, 105
Hiner^ cottages, 677
booting, 673
Inch, defintuon of, 301
Minette, 53
Uiniires, definition of, i
Mining, comparative healthiness of,
683
definition of, i
labonr, principles of employ-
ment of, 637
law, in France, i
In Italy, i, a
in the United Kingdom, i
in the United States, 8, g
statatea, 656
relaiinKto Derbyshire, 655
to Foreet of Dean, 655
•nbdivIdoD of the snbject, 2
MiBceUaneons pnlveriier*, 563
Misptckel, treatment of, 6ti, 612,
613, 619
Mlss-flre. 217
.618
Hona and Parya mines, cobbing at,
UoDier system of nsing concrete.
Monitor, 396
BX. 733
Montana, copper deposit* of, 37
Monte Catinl, flora of, 104
Monteponl, fiardloia, adtt at, 435
roasting calamine at, £15
Moore, pnmps worked nndergronnd
by hvdiaiilio power, 469
Morana, dres^g of gra^t« in,
623
Mortality, comparative flgores, 6S3,
684
Mose-boz, 373
Mother Lode or "Oreat Qoartz
Vein," CaUtoroia, 45
Motion of particles in water, 568
Mount BischofF, dresaUig tin ore at.
437
Unsseler'B lamp, 530
Mulberry mine, near Bodmin, 19
mode of working;, 39a
Mnrgne, on the redstanoe to air-
current dne to aides of ^rway,
SI I
N
Nakaqua Copfxb Co., magnetic
separator oaed by, 606
Names of places, intormation
afforded by, no
Natntal gas, oonveyance by pipea,
373
occurrence of, 59
Hatnial ventilation, 482
Needle, 161
NeD-Stasafnrt mine, electric raO-
way, 371
Nevada, Cometook lode, 76
mineial deposits at Steamboat
BruDswjok, antimony o)
Caledonia, cobalt ore in, iS
nickel ore in, 60
Idria, working by refieoted day-
light at, 513
South Wales, alunite In, 20
tin-bsarbig alluvia of, 85
Zealand, trees nsed for mining
purposes, 139
Nickd ore, discovery of, in New
Caledonia, 99
ores, mode of oocairence of, 60
Nitrate of soda, mode of occurrence
of, 6a
mode of working, 3S6
prepacaticn of, 608
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Nitro-oellaloae, 315
Nittogen '
Noble and Abel, on fired gnnpowder,
Hoetting, on tbe oil-flelcb ot Bar-
Nog, 23a
Holten, on finding devUtioD of bore-
h(dM, 148
Northampton, deep boring at, ti8
NorthwnptoDBhire, mode of working
iron on, 386
North Lancashire, dressing luema-
ttte in, 614
working h«taatite deposit*, 343
rojaitiee in, 654
Kortb Wales, iron pyrites, 83
slate mines, 313
irasblng pit a«ed in, 539
Northwich, salt beds of. 75
Nnnnery Colliery, steel bdwns, 356
Njstagmns, 6SS, 689
ntioua, 337
dresalng'of, 636
Octiseniui, on tbe origin of the
nitrate deposits of South America,
63
Oejnhansen'B sliding ]oint, 1 28
Ogle, Dr., on annnaJ death-rates in
TBrions tiadee, 683, 6S4
Obio, mode of oocnnenoe of natural
rain, 59
effect of on safety fuse, 217
fields of Bakn, 65
of Bormah, 65
of the United Btates. 67
Oil-wells, geses met with in dnloDg,
Open-fire drying. 593
Open works, iS^
Optimna drUl, 189
Onnerod's detaobing link, 416
Osceola Co.'b mine, arc-lamp at, 525
Otago, New Zealand, lodee of, 8
Otto's system of aSrial ropeway,
382
Outcrop of lodes, 98
Overburden, z86
Orerbaud stopii^. 329
advantages ot 33'
OverlM) fault, 90
OTsrwinding, 432
Ovuli, 5t
Ownership of mineials, 653
Oxygen, absorption of, 480
determination of, in tbs air,
aecesnty for a large propoitios
of, 505
Oiokarite, dre«!doK of. 626
extraction o^ Dy beniine, 6c9
mines, Boiyslaw, iDBammabte
1, 477
FACXIsa plunger pump, 453
pnmp bucket, 44S
Faoo* (S. America), 100
Pan, for amalgamating gold oie^
633
for grinding and ama^;amatiiig,
for prospecting, 538
Paragenesis of miDorals, 97
Parian cement, 613
preparation of. 634
Parodi on the Sicilian sulphur beds.
83
I Paijs mine, extiaotion of copper b!
I solution, 307
1 precipitation at, 616
; Pass. 333
' best form of, 34S, 349
I Patterson's stamps. S51
Paimui'a roUer for HuntingW
i mill, 561
' Pay-bill for payment hy messEe,
I 63a
I value of product. 643
I weight, 640
' Pay-lead, 318
Payment by measnre, 63S, 6i9- «V
time, 637
time and measnre, 641
value ot product, 641
weight, 639
Pearce, on the tin-lodes of Cow-
wall, 7
Peeker, zza
Penhall's mine, Cornwall, saix»
sion of faults at, 92
Penrbyn slate qoarry, 2SS
Pensions, 693
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Peroolation of sarfaoe water Into
worUnga, 419
PercnBeion tablM, 584, 5S9
PerpoDtUcalar ahMlta, advAUtagea I
of. 3*5
Pestvena. loss of gold at, 631 |
PeCrolenm, 65, 66 !
coDTsyance bj pipes, 374 .
eitraotion by nelU, 304 |
Petrolenm eo^De, 163 ;
for pumping, 445
for workiiig drill, 180 I
Pettenkofer. on tbelimit of carbonic
add in air, ;oi
Pbenolpbtb^em, nso of, in lime-
water test, 503
PhiUipg, on the mica of North
Oarolina, 58
Pho«pbate kiln, Amerioan, $94
Phosphate of lime, 67, 69
discovery of, atBeanval, France,
Id Soath Carolina and Florida,
68,69
sosrch for, by piercing. 107
treatment of. 6z6
weathering of, 611
Photometric teats of light given by
safety lamps, 519, 510
Physical properties, dressing pro.
oesses depending on, 568
Pick and gad work, 154
handles, 153
Picking by hand, 541
Picks, 152
mechanical, 199
sharpening, 153
with sepante bladea, iS3
Picric aold, explosives containing,
Pieler lamp, 499
testing for Sre - damp with
hydrogen flame, 50a
Kercing, 106
p^ty timbering, 245
for levels, 234
(or shafts. 239
Pilar, on Franke's mochaaical chisel,
199
Pillaring of slate, 81
plane, 314
raiais and cbambers, working wide
lodes with, 33S
left as permanent snppoits, 309
worked aw«y,3i5
Piae, varieties used for mining
pnrposes, 227, 228
Pipe- lines, 374
Pipes, oonveyance of mluer&la by, 349
BX. 735
Pipes — continufd.
for compressed air, 170
for conveying water, 295
for pamp oolomn, 450
wooden, 450
Pitob lake of Trinidad, 23
of a shoot of ore, definition ot,
pnrifloation of, 598
pine, 327
Pit-bead frame, 394
Plane tables. 579
Planing maohineB, 565
Plank tabbing for sliaf tis 266
Plants, Indications of minerals
afforded by, 103
Plaster of Paris, 613
prepaiation of, 634
Plat, 405
Plug and feathers, 30S
Pltunblsm, 687
Plnng«rpamp,4ji
Platonic rookf, 3
Pneomatio hoisting, 427
jig. S8g
Poetsch's freeilng process, aSi
Pohl£ pnmp, 470
Points and crossings, andergroond,
354
Poling, 236
Pollution Prevention Act, lUvcrB,
, carbonic
667
Pon^band lead :
acid at, 475
Poppet heads, 394
Post, 237
Potassium aalta, depoxits at Stasa-
furt,7o
discoveiy of, at Stassfait,
96
method of mining, 315
treatment o(, 627
Potoei, 78
Preciidtation, 616
Prenumns for good conduct, 652
Preparation of ores.— &« Drgssiko,
„537
boi,a95
Pricker, 161
Pifbram, deep shafts at, 404
underground Are at, 70S
Priestman^ grab dredger, 176
FrinciplsB oiemployment of mining
labour, 637
Prop, 244
Props, Iron and steel, 365
.V Google
Prospaoting, or search for mlnenU, ;
Proapeotor, qiudlflcatioiu of, 113
ProTideat looietieB, 690
FmwUiaccidBDtiffomiiiMi-engiQes,
Padding DWchlDe, AastrsUa, 539
pollej-fraiiie, 394
Pnaej^397
PglMtOT, 621
Palsometer, 46S
PnlTerlMT, Crclone, 563
MhwIodV 547
PnlTCiiwrt, mitceUaiieoiu, $63
pnennuitlc, 56J
Pump colnmn, 450
for extrxcting brine from bore-
bola, 306
lifting, 44S
plnoger, 451
^nnKer, MTMitagea of, 451
Pohl£, 470
polaomeMr, 46S
Iti«dler, 4^7
Rlttlnger, 454
rods, 445
comilerbaluioing. 457
TtlTM, 453
Fmajdiig BD^nM, compoimd, 443-
445
dot; of, 473
plftcttd nDd«rgtonad, 466
idngla ■cting, 443
maohlnery, movii^ btArj parts
pluit, fihakamanile mliis, 461
Pomp^ dninage b;, 441
driven compreued air or eleo-
trioitj, 470
drowning of, 45a 446, 467
wooden, 450
worked by hydranllo power,
469
Pnri^riug water from dreuing
works, 667
Pyrites, CamarvonBhire, S3
mode of working in North
Walea, 309
worked opencaBt, Rio Tinto,
Qnairiei — amtintied.
slate. North Walea, 312
[ undergroand siate, AideoDec,
3H
atone, Bath, 310
I Qoairy Poncing Act, 667
Qnaitering, Bampling by, 633
' Qnenaet quarries, premlomB for good
conduct, 652
! Qoiokaand, Haase process of sinldiig
I In, 283
I Poetech process of einkiiig in.
383
Trigei's process 01 sinking in.
277
QnioksilTer, chance discovery of. in
California, 94
mines of California and Nevada,
Becker on, t6
mines, DDbealtblnesa of, 687
Bails, 3SI
Railways, eleotrio, 371
surface, 376
nndergroniid, jji
BaiiuneUb«rg Hine, Haiti, pyrites
deposit, 33
Band, gold output, 43
Ratchet drill, 155
Bating Act, 65s
Raymond, on indioative plants, 104
Recreation, 696
Red clay of New Caledonia, 2S, 60
Bed bar (JohanneebuTfc), 103
Redonda, phosphate of alumina at,
69
R^idat:
_ latlons for mines, working, 655
B^ulations.— •See Acra, 656
Beaerroirs for oompressed elr, 16S
foi hydraulic mining purposes,
393
Redstanoe to alr-cnrrent, J10-512
Bestrongnet creek, dre^nng of tin
method of working tin-bearing
gravel, 316
I of tlnore in aUovium
of, 8s
shaft sTe
shaft sinking a
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Retfonl&ted masses, 19
RetortiCK amalgam, 600
snlpbur oraa, 600
RetDmuiK charges, 64X
Reumaiuc's automatic speed cbeokar,
KevolTiDj; round table, 583
Reversed fault, go
Rewarewa, 13^
RboBesmor mine, Flintshire, 435
Rice's olotob, 369
MBS, conditiotu offoct-
Ricbmond v. Eureka oase, S
Bickard, on Mouot Morgan mine,
QneensUnd, 49
on the saddle-ieefs of tbe Ben-
dfgo gold-field, 47
Kebeck's stove, 595
Hiedler pumps, 467
RilBes, 399
Rlgg and Helklejohn's machine,
203
Binobiosti, 475
Rio Tinto, arc-lamp at, 535
character of ore at, 33
geology of the diatxict, 31
- >n. 33
lodes at, 33
mines, shipping orrangemeuts
at Huolva. 3S0
opencast, 289
mllar and chamber workintini,
338
precipitation at, 616
timbering for levels, 333
treatment of copper ore at,
Rise, difficult; of ventilating, 486
mode of ventilating, 4S8
Rises, method of timbering, 344
Rlttinger, fall ot spheres in water,
568
Rittlnger pump, 445, 454
Rittinger's perctusion table, 584
Rivers Pollution PrEvention Act,
667
Rivers, smldng shafts in, bj freeung,
280
Roasting, 611, 613
Roberts, C. Warren, sleeper, 353
Boburite, 315
fumes from explosion of, 481
Rock-boring oompelitioD, 159
Rock-drills, 177
Rock-salt at Stassfnrt, 70
Rods for mau-enginea, 535
for pnmpe, 445
Rolland'a flreless locomotive, 363
lEX. 737
Rolls, Cornish, 553, 554
Erom, 554
Roof of n l>ed, definition of, 5
slate mining, 312,313
Root's blonor, 494
Rope haolsge, 365
preventing shock to, in winding,
437
socket, 139, 140
Ropes for wini^ng, steel, 399
modes of capping, 402
testing. 437
Bossigneuz system of counterbaiaiic-
ing. 459
Rotary mactiine drills, 178
waeliiag maoliiDe for diamonds,
540
Rothliegeodes in Hansfeld district,
39
Botlischanberger Stalin, 434
Ronmania, salt mines, 311
Rounmniui miner's bat, 673
Round tables for picking, 543
for slatces, 58!
Rowoldt's stove, 597
Royalties, 654
■Hiilng acale for, 654
Roelle's stove, 596
Rains, Indications aSorded by, 109
Running loop, 447,
Rossia, manganese ores of, 57
OOCnrrenoa ot qaicksilver in,
73
Rylaud's glass-lined pipe, 171
Saddle reels, Victoria, 47
Safety catches, 436
on cage, 418
fase,117
gear for hauling men at Bory-
lamp, nsed for testing for fire-
damp, 499
lamps, 518
St. Agnes, Cornwall, tin lodes of, 84
St. Day mines, heat at, 670
Saint -Etienne, mine- waggon uaed
at, 358
St. Just, strike ot lodes at, 14
Saliabnry Uine, Joliauaesbuiic, 43
Salt, discovery of in Cleveland
district, 96
excavating by water, 336
extraotion by wells and bore-
holes, 304
3^
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73« U
Skit — otmtUued.
minerals assooiAMd with, 97
mines. Cheshire, 31 1
Roanuuiu, 312
OOcaTTBDOe of, 7J
prepuatliui of, 6 "
«S
SalikauDmergnl, mode of working
■alt-marl, 307
Bampling bj bknd, G33
quartetiug, 633
taking oDt imall lots, 633
trenching, 632
object of, 633
machine, Biidgman'i, 635
Brnnton's. 63s
ClorkBOD'B, 634
Colaiado, oaed in, 634
■boTel, 633
Sandala, 673
Saa Domingoa, 34
Saud-pnmp, 140
Sand-reel, 139
Sandstone, blttmuDona, California,
intarstitial spaoe In, iS
lead-bearing, Hechemich, 5, iS
Bilver-beariag of Utah, 18
BarrBQ and Vieille, on the docompo-
Bition of oertaia explosives, 112
Savage mine, heat at, 670
Sawing nuudilnea for stone, 564
Saws, oircQlar, nse for nndwontting,
for catting stone, 154
timbermen's, 231
Qsed in getting freestone, 310
Sawyer on nnderset of props in in-
clined beds, 244
Saxon gad, 1 54
mmer'a ump, 516
Bctuliffer and Bndenberg'a speed
indicator, 533
Sohiele fan, 497
SobooU, 68z
Sohrader on France's meohanical
chisel, 199
Sohnli'a stove, 597
Sootoh flr, liS
lamp, 516
Scotchman's United mine, bore-
hole at, 14S
Scraper, 160
Screening, 56G
Screw-coDTejors, 375
Seams, 18
SwfloniDg of tlmbei, 330
Sector wife tope, 401
Seoorite, 3i«
SedimeDt'tobe for diamoiMl tirii:.
119
Self-dlscbarglDg skips, 413
advantages of , 4 1 7
Self-oiling pedeatals. 361
SelTsge. definition of, 1 1
Separator, Frongoch, 576
Jacom^t; and LenicqDe*ih 575
Lodcttart's gem, 577
siphon, 577, 579
Separators, upward corrent, 574
Sergeant drill, 193
groove-catter, 199
Serpentine, ooonireDce of asbestos
of nickel in, 61
Sets or frames, 234, 236
&e;ssel, France, Utnminoos lime-
stone of, 33
treatment of asphalt rock of.
S98
Shaft accidents, 705
arrangement ot pomps in, 451,
461, 464, 465
linings of iron, 363
natnral ventilation of, 486
rolls, 446
use of air-pipe for ventilating,
Shafts, cost of sinking in iraterj
crooked, arrangement ot pnmp
rods in, 446
deep, at Pribram, 404
frewdng process of sinking,
278
forworking mineral depositSijoS
for working veins, 325
Eind-Chaudron process of
sinking, 271
Uned wiUi concrete, 353
lined with mssonty, 352
natDtsl ventilation bj two,
483
Foetsch's freetlng process for
sinkii^, 281
sank by boring process, time
required, 277
timbering of, 336
Shaft-sinking, 325
by incandescent lamps, 524
throDgb bed of river, 3^
Shakttnantle Mioe, pnmping plant
at, 461
Shanb' system of treating caliche.
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Sbebs Mine, BftrbertoD, 44
Qold Hlne, aeri&l iopaw&7 at,
384
Shell T)ump,
Shipping o
Sboad-stonea, ro6
Bboe of atam|w, 549
wooden, 673
Shoot ot ore, defiDltiou of, II
Shoots, 348, 373
inoutb for ngiilatii^ dis-
cbarge of, 413
Shovel, 151
Sliower'lxatb for miners, Ancin,
6gt
Siberia, freeiiog method of sinking
Sieiliaii miner's lamp, 515
Sicilian mines, steps for deaoent or
ascent. 527
Siollf, modes of worldng sulphur-
bearing limestoae, 331
occurrence of snlphnr in, 83
Sickness, 6S3
Side botes, 310
Sidings, endleM rope sjstem, 370
Sieves, 566
Signalling, 430
from cage, 533
Sill, 133
Silver, cbanoe discoveries of, 95
Silver oree, occurrence ot, 76
Broken Hill, N.S.W., 78
Calico, California, 79
Comatock Lode, Nevada, 76
Eureka Bichmoud, Nevada, 76
Hnanohaca, Bolivia, 78
Kongaberg, Noivm;, 12
Stormont, Utah, 79
treatment of, 638
Silver-bearing mndatone, Utah, iS
SlmultaneoQB fnae, 220
Single-rope haulage, 365
Sink, Z3Z
Sinher-l>ar, 139
Siakins bj compressed air mettiod,
mflnenoe on health, 6S9
Klnd-Chandron method, 171
Foetsch, or freering method,
181
271
Triger's method, 377
Siphon, draining mines bj, 437
Siphon tepantor, 577
Bkertchlj on the mioiog and knap-
pinf; ot Bint, 41
Skip, 404, 410
loading Id sbalt, 410, 41s
«elf -discharging, De Beets In-
clined shMt, 4IZ
for perpendionlor shaft, 415
Skntterud, col>alt ore, 27
Slag-heaps, indications afforded br,
to8
Slots, oboiglng holes forrandiug, 219
cironlar saws nsed for, 564
dressing mootiineB, 565
loss in dressing, 631
loss In mining, 314
methods ot working, 312-315
Mines (Onnponder) Act, 659
king, 312-3
. der; * - ^
of, 79
plonmg moobines for, 565
preparation ot, 628
splitting of, 545
Madges, 350, 375
_ joint, Oejnhaaseo's, 128
Sliding scale for rojalties, 654
SUp. 473
Slopes, 308
Sludger, 128
Sluices, 397
Smith, Dr. AugOB, on the candle-
test, 501
on the pollution ot the air in
mines, 480
on the proportion of oxygen in
respirable air, 506
Krocess ot testing air, 503
Icliard, on the gold-bearing
conglomerate of the Trons-
Bnell, on miners' nystagmos, 689
Snore-piece, 448
Snow, disappeaiance of, from i>nt-
crop of loae, loS
Societies, provident, 690
Sockets, joining two ropes by, 494
-- . - ,233
Solfatata of Pozsuoll, lulphnr from,
82
Solution, extraction of minerals by,
30s
preparation of borax by. 60S
nitrate of soda bj, 608
potassium chloride by, 608
phosphate of lime in, 68
treatment in, 637
Somorrostro. endless chain haulage,
379
self-acting incline, 376
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8orb7, on tha origia of tbo Clare-
686
Soogb, 433
Soiuidliig, lasting gronod by, 705
SonroM of miDenl •apply In BrltUb
I«U», 6ss
SoDth Af nok, diioorery of dlwoonda
1", 93
draulDg of diamondB, 611
rid ore deposita, 41
Oarollaa, pboaphate badt, 68
treatmeDt 01 phosphate of lime
in,6a7
South Staffordshire Hloat Dnlnage
CommisatoD, 474
Space reqaired per bead, in rooms,
676
Spain, cupreous pyritea dsposlts of,
3'-34
OOODirence of qniokiilTet id, 72
SpalUng, 544
gpathoae ore, oaloliiation of, 613
Spear-Tod, 445
Speed indicator foi winding engine,
, 533
Spiral dram, 393
Splitting air-cmrent, 510
slate, 545
Spragae electdo diamond drill, iSo
Sprengel type of explosives, 315
Spring itampa, 551
Sprnoe fir, 338
Sqaara-Bet syvtem of timbering, 346
Sqalb, 218
Stalla, 309
Stamps, gravitation, 548
pneomatic, 551
spring. SSI
■team-hammer, 551
Standards for wire ropeways, 383
Stanley's tnnueller, 307
Stannaries Act, 668
StapS, on prospecting for phos-
phorite, 104
Staufnrt, disoovei? of potassiam
aalts at, 96
occarrence ol potassiDm aolte
at, 70
preparation of salts at, 608
salt minaa, salphnretted hydro-
gen at, 479
treatment of potassium 18^15,627
vorkings for camallite, 31S
Statiooary engines for haulage. 364
taUe of Linkenbach, 581
Btatntaa affectlis mines or qoairiaa,
6j6, 659, 663, 66s
Mining. 656
iSet Acts or Paruahutt, 65 s
8t«Mnboat springi, NeradA, 7$
Steam Jigger, 173
engines for winding, 390
hammer stamps, sSi
jet for ventilating, 493
process for sulphur, 600
shovel, 17J
atora. 597
Steavenson twist drill driven by
power, 180
Steel beams used for supporting
levels, =s& 35B
car wheels, 357
fnunes for levels, 359
shafts, 263
mine-waggons, 356, 360
props for working places, z66
pump rods, 445
sleepers, 352
wiie-ropes, 399 .
Stein's endless belt, 586
Steliner, on the lateral sesretion
theory, 15
Stempels, 340, 339
Step-fault, 88
Stepa for descent and ascent, 526
or stopea in open works, widtb
of, 386, 288, 389
Stock works, 19
qnicksilver ore, 73
silver ore, 79
tin ore, 19, 84
zinc ore, 87
Stokes' alooholTBservoir for snfely
lamp, 50a
Stone, prepantion of, 628
breakers, 546
Stoping, overhaod, 329
□nderhand, 327
Stoves, for drying, S94
Jaoobi'a, 597
Krom's, 595
Kiebeck's, S9S
Rowoldt's, 597
Roelle's, 596
Bohnlz's, 597
steam, S97
Strap[dag pktes, 445
StratiSed deposita, 4
Straw for firing shots, 318
Stream vorks^ tin ore, 85
Strength of ezploatves, 316
Stretcher- bar, 197
Stretchers, 713
Strike, definition of, 5
infiaence of ottange of.onTeinB,!}
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StringT b"^ "9
StruvS'i ventilator, 494
Staddles, 237. S43
Stall, 327
StnrgeoD on the effioloio; of com-
pietBodair, 164
BtarteTUit MUl, 563
BtjTift, (crapUte in, 50
Snbliination, fonniktioii ot relna bj,
Bnb-Wealden boring near Battle, 96
Sactlon dradKe, 177
pipe for brine well, 306
pamps, 44S
Sndbarj, diacoTorj of nickel ore »t,
nlokel orei 0^ 61
Suffocation t^ gSMa, 707i 7>o
Snlphate of iron need for preMrflng
timber, 231
Snlphnr, diBtlUation of, 600
HqnatioD of, 598
mode of ooonrrenoe ot, 81
prepBiKtion of, 629
rock, Sicflj. flr&^mp emitted
by, 478
Bulk Mine, Califonila, 74
diecoTerj ot qnlok^ver at,
96
Kaa from hot epringa, 470
bearinB limeetone in Sicilf,
mode ot working, 321
■eamB, oatOTOp of, loz
Snlphnretted hTdrogen in minee,
479
Snlpbnroiu BOid In mlaet, 479
Snmp, 326
Supporting excavatioDS, 327
aornice accidents, 711
drainage, 439
lodioationE gnlding the proi-
pector, 97
SnrTBjlog bore-holei, 147
SnrvajB, danger from iuaccarate,
707
Sussex, preparation of gjpsnm,
624
Saumann electrio lamp, 533
Sntro Tunnel, Nevada, 436
Swab-stick, 160
Swage, I
Sweden,
iSi
n ores of, 54
mce of zinc on
searcbing lor iron on
magnetic needle, 11
Switzerland, workings
307. „
TabLiB^ Jacomity and Lenlcqne's,
LinkeDbaoh'a. 581
percnssion, 584, 589
lacking, 543
plane, 579
revolving roand, 583
lUttinger's peroasalon, 584
roimd, 5S1
Tabular deposits, 5
Tachometer, 533
Taegliobsbeck's report on hoesing
of miners, 674, 679
Tagleff's spouting oil-well, Baku, 65
Taillnge. 343. S»S
Tamaiack copper mine. Lake supe-
rior, 36, 37
Tamping bar, 160
cb^e, 317
Tapering ropes, 404
Taxation of mines, 625
Tasmania, dressing tin ore in, 630
Teagne's aspirator, 493
noieeless valve, 453
Teel'a Horsb, boiai d^ioeit, 33
Telephones used for signalling in
mines, 421
Temper screw, 140
Temporary dam, 433
Testing air of mines, 498-510
ropes, 427
Tbamea gold-field. New Zealand, 13
Thaisis, pjiltes mines, 34
Tliawing dynamite, 213
Thickness of bed, measurement of, 5
Thrift, 690
Throw, or heave, 88
Throw of a fault, deSnitloD of. 89
mode of determining amount
of, 89
Timber, decaying, aSocta air of mine,
480
kinds used nndergronnd, 327
preservation of, 229
seasoning, 330
supports compared with steel,
257
used in Aastralia. 328
in England, 227
in United States, 338
withdrawing, from mbbish,
Foxdale, 338
Timbering in loose ground, 343
level^ 232
pigsty system, 234, 239, 245
shafts, 336
special excaratlong, Uartz, 341
square- set, 246
working places, 244
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74^ IN
Time ocoDided in dMoent uid
BaccQt at Uanafeld, 532
payment by, 637
and mea«nre, paTmant bj, 641
Tin ore, alluvial depoait at Ra-
BtroDguet Creek, 316
calcination of, 613, 613
dreatlng of, 629
lodes In gninlte, 7
mines affected by Alkali Acta,
node of oooamnoe of, 83
aepaialion from copper ore, 609
slockwork. Mulberry mine, near
Bodmin, 19
Toadrtotie, infiaenoe oa lead velni
in Dert^bire, 13
Tonite, 315
fomei from explosioo ot, 481
Tooli nied for working timber, 331
Tootbed rolla, 556
Torohei, 515
Xoipado, 304
TransmlaMou of power, 163
ItanipoTt abore gionnd, 373
nndergronnd, 348
TreadweU Mine, Alaska, 47
Treatmentof ore*.- " ~
TrMeaae'* valve, 453
Trencbing, sampling by, 633
Tribute, 641
advantages of worklog i
646
.643.
disadvantagei of working on,
644,645
system in Coloiado, 647
at yeitmiog, 649, 651
Triger's method of sinking, 277
Trimming atone by hand, 546
Trinidad, Pitch Lake of, z3
dressing of, 619
purification of, sgS
Tripoli, occuneDco of beds of, In
^olly, S3
Trommels, 566, 567
Tfouvi, appi
bore-holea,
Trobi, Ss
Truck Acts, 668
Tubbing for shsftt, cast-iron, 36S
wood, 266
Tannelling machinee, 306
Turbine, used for hoisting, 389
TurgU'Ocna mine, 313
Tom pktoa, 354 .^ . .^
Tuscany , occurrence of bone acid, 35
preparation of borio acid, 620
Tutwork, 638, 639
Ulvirbton, bunatlte deposits of,
19
Umber, dressing of, 6x6
■earohing for by piercing, 106
UDdercurrents, 299
Undeieutting macblnea, 199, 303
Undeiground pamfdug enginea, 466
workings, 308
Underhand stoping, 337
Underlie or nnderlay, definition of, 9
United Kingdom, death-rate from
aocidents, 700
United States, candle-botder used
in. 5M
gathwing of natural ice, ji
limp uaM in, 516
l^al defioIUoD of lode in, 9
occurrence of(K>pperin, 34
gold ore, 45
uonore, 54
lead ore, 55
natural gas, S9
petroleum, 67
phosphate of lime, 6S
qnlcktilTer ore, 71
silver ore. 76
trees need for mining puTposes,
33S
Universal pick, 153
Unstratifled deposits, 4
Upcsat shaft, 4^
Uppers, dust from boring, 6S5
Upthrow, 91
Upward-current aepaiators, 574
Utah, tilver-bearing sandstone, 79
VAL-DB-Tsi.vKBS, SwitEerland. bi-
tumlnons limestone of, 22
Value of product, payment by, 641
Valve, butterfly, 453
double-best, 454
Jsn Ham's, 453
Hake's mouth, 453
ordinarj leather, 448
Teague s noiseless, 454
Trelease's, 453
Van den Bioeck and Ratot, portable
boring outfit, 117
Van lode, length m. 1 1
Van mine, fire-damp at, 476
method of working the wide
lode, 331
Vanner, Krue, 585
V-bob, 446
V^etation on outcrop of lodea, 107
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Veins, daSnitioD ot tvm, 5
heave sideways caused b; slip
along Ijne of dip, 91
inflnence of change of strike on,
13
of enclosing rock an, li, 13
intenectioTia of, 12
mechanical filling of, 14
Diodes nf working, 325-340
name applied to slate beds in
North Wales, 81
origin of, 14
Tarjiog width of. 16
Zimmermann's rule for finding
faulted portion of, 91
Veinstone, deBnitioti of, 11
Velocity of air-onrrent, meaaure-
ment of, 506, 507
Venezuela, discovery of gold in by
Plassard, 94
occnrrence of gold in, 44
Ventilating applJauceB, ^cleocy
fans, 494
furnace, 490
steam jet, 493
water blaist, 493
falling down shaft, 4S6
effect of, on limbec, 230
measurement of amount of air
passing, 506
natural, 482
Victoria, gold-flelda of, 46
Villiers' stopping gear, 435
Viola calami naria, 104
Volcan ic omanatioos.s alphur f T0m,8 1
Vom Satb on the ontcrop of the
silverTeins of Butte, Montana, 98
VoD Cotta, definition of a mineral
vein, 6
on the Zwitter of Altenberg, 84
Von Groddeck, definition of a
mineral vein, 6
Von Sandber^er, definition of a
mineral vein. 6
on t he lateralsecretion theory, 1 5
Vugs, (definition of, 6
Vukauo, solphnr firom, 83
W
Waddle fan, 497
Waggons for underground nse,
355-360
points to be considered u
signing, 361
Wales, barracks for workmen, 676
manganese ore In, J8
lead ore in, 331
slate in, 79
nnderground workings for state.
Walker's circolar saw, 303, 304
detacbing hook, 413
shatter for Ouibal fan, 496
Wallace on emanations of carbonic
acid at Alston Moor, 475
Wallaroo lode, discovery of, 93
Walling, 349
WallinK stags^ Oalloway's, 409
Wall-plate, 236
Wall -posts, 340
Walls, Clovehmd, 315
Kestiniog, 312
of a lode, definition of, 10
Walton Brown on the resistaooe to
air-ourrentx, 511
Ward well stone -chaonelling ma-
cbine, ao3
Wanning pan for dynamite, 313
Warocqnftre, 706
Washer, Anstraiian, 539
De Beers, 540
revolving dram, 541
Washing ores, dec.. 538
Wash-out fault, 87
Washing-pit used in North Wales,
539
Water, amount used b; siphon
separator, 579
amount nsed in stamping, 551
barrel for winding, 437
colnmn compressors, 165
excavating by, 226, 293
from dreuing works, purifica-
tion ot, 667
spray for laying dust, 6S5
tanks, automatic, 43S
used for rending rocks, 308
wheel used for hoisting, 3S9
Watertight linings for shafts, 366
Weathering of diamond-beuing
rock, 610
fire-olay, 611
Ironstone, 61 1
phoephate of lime, 611
Wedge, 154,208
Slliott muIUple. Z08
Wodaing-orib, 367, 270
Weigot, payment by, 639
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744
boiliiig by rotation, i
driven, 137
WeUs light, 516
WeUb bMracks, 676
dreaaiiigo(,63S
lead on, 331
miner'B ologa, 672
slate miaea, 7^ 312
Wensttom ma^etto separator, 605
Werner, deflnitjoa of a miQenl
Wirfa stopping gear, 423
West and Darlington, ii7dranlic
counterpoise. 458
hjdrsnlic plangers for working
inclined rods, 447
Wheal Hary Ann, HecCion of lode
at, 6
Wheelbanow, 350
Wheels tor nine-naggons, 357
WhipsideiTr, 3S8
White's sleeper, 353
Whittle;, on the "Great Qnarti
Vein " of California, 45
Wicka, candle, 513
Wide veins, meUiod of working,
33"
Wielicska salt mines, 315
timber chocks, 245
Wind-bore, 448
Winding, 387
drum, 391
engines, 390
loen at Cam Brea mine, 533
pulleys, 397
removlDK water by, 437
Windlass, 388
Windniille nsed for working pnmps,
Winstanley's machine, 104
Winze, 326
Winzes, use of for ventilating, 4S9,
r.sS6
Witwatenrand, 41
Wolfs magnetlo lock for alii:
lamps, 523
Woodbnry o _ .
Wooden pipes, 450
plags Dsod for rendiDg t«t
ao8
paUe; frame, 39;
Working barrel of pump, 44S
■ led poudon, ^t-'
descending, 341
mineral deposits, meUwd! ''
2S5
places, iron and ated snppjr-
265
snpported by nuwonir, ^il
tirobering, 244
regnlations for minB^ 6^5
Workinga. carbonio add iaolil, ;-'
lay big out open, 2SS
Workmen, hoosing, 673
Wotherton mine, Sbropsliire, ij
Wrist, 310
Wrysgan mine, 314
Yellow Jacket mine, heat af. "?
ZiUHEBUAN's rule tor finding !^
part of a vein, 91
Zinc blende, minerals iftooU'
Diepeollticben, method
working, 346
ores, calcination of, 611, dI5
dreeing of, 625, 630
occnrreDceof,85.S6
Zwitter, or tin-bearing rock al A!l>i!
berg, 84
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A CATALOGUE
OF
SCIENTIFIC AND TECHNICAL WORKS
CHARLES GRIFFIN & COMPANY,
MESSRS. -CHARLES GRIFFIN & COMPANY'S
FUBLICATIONS may be obtained through any Bookseller
in the United Kingdom, or will be sent direct on receipt of
remittance to cover published price. To prevent delay, Orders
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INDEX.
AHGLIN (a.), Dnisn of StrDotona, . 3
BBBINQER (J. J. ft C). AMTins, . *
BBOTHEBS (A.). FhctomfibT. ■ . 4
BR0U0H(B.a.),Miiia-8u*eTii>f, . S
BROWWE <W. RO. Studentri Mechmial. 5
Poniidatioii* of MacLmnics, 6
Foal ud Vftia, . . . . S
COLE IPnL), Pnctioal GMloiar, . . e
CBIHP <W. SO. Sams* Diwo«] Wcrka, 7
CRIMP t COOPER, FackM-Bodc tot
anrrsTon, 6
CROUPTON <R. £.), Dmunoi, . B
CUTHBERTBON (JohD), Hioinc Arith-
DAVIS (Prof.), BioloffT B
Ths Flowtrint Plut, . . . B
Zodogiod Foeket-Book. . . . S
DONKIN (BcyuJ, Qu, Oil, ud Air
BwiiHi S
DUPR£ftHAKE(MHiiulo[Cb*miMn(>, B
ETHBRIDGE (R.), 8tntlsn|4ikBl
Oaolim »
EWART (Prat), PnMmllni ot PUh . »
VIDLKR (PruT.), Bridse-CaDMnatiaa, ID
POSTER (Prof. C. 1« N«*«>, On ud
Stone HiaioR, 11
GIBB (Tboa.), Copper, .... 16
GRIFFIN'S Electrical Enginaen'
Price-book 12
GRIFFIN'S Engineering PublioMiom, 13
QRIFFIN'S HeUllurtiical 8erie>, . . 35
GKIFf IN (J. J.), Chemical ReoreUioiu, 12
G0RDBN (R.), Tnvma Tiblca, . . 12
GUTTMANN (0.), Blaating, . . 11
HUaHBS(H.W.),Caal)linins,. . 15
HURST (G.H.),Caloun and Varaidiea U
JAHIESON (Prof.). Steuu Engine, . Id
E]enienta>7, IE
Applied Mechanics, .... IB
Hagnetiam and Electricit;, . 16
JENKINS (H, C). MetallnigiEal
Uaefaineiy, ^
KNECHT&RAW80N, Dyeing, . . 1?
H'MILLAN (W. O.), Electro - Metal-
lorgT. IB
HDNRO ft JAMIESONS Electrical
Pocket-Book 19
MUNRU (Dr.), AgricultunJ Cbtmiatrj, 19
HUNRO (R. D.y, Kitchen BoU>
Steam-Boilen, ManagBnieiit al, .
NYSTROH'S Pooket-BocA br
PHlLUPSftBAUEBHAN.lUttftotT.
POYNTINU (Prof.), H«ui UeiHt* tf
tha Earth
& THOMSON, Phrooa, .
BAN KINK'S BngineeiinK Worka,
A Hantia] of Applfed Hecbwk^
[ Hm-
-AHanualotCiii
— A Hauoal of Haehinery aj
< — -^ A Manual of the StFam BniriiM and
other Prima MoTcia,
L'MtU] ItDlte and Tablca, .
A Hecbanical Text-Book,
HiaceUaneoiu Bdentiflc P^ma,
REED (Sir E. J.), Stability of Shipi,
REDGRATE(Q. B). CeuMnb^ .
REDWOOD (B). Petroleum,
RICHMOND (U. D.), Dairy ChauatiT
ROBERTS-AUSTEN (Prof.). Metal-
InrgT
Allojs
ROBINSON (Frof), HydniOJe*, .
ROSE (T. K.), Gold, Helallutf^ nl,
SCHWACKHOFER ft BROWNE.
Fuel and Water, .
SEA TON (A. E.), Hwii
SEATUN ft ROUNTHWAITE, Maniac
Engipeen' Pocket-Boob, .
SKELEY (Prof.), Phjrucal Ueolosr.
SEXTON (Prof.), MBlaliuisr.
' — ^uantitatiTB Analyail,
Qualitative Analyaia, .
BHSLTON-BEY (W. V.]
Guid
aMlTH (Prof. R. H.}, Graphic Table*
HiofMea;
enta,.
THOMSON ft POYNTING (Prefix),
Text-Book of Ffayuc^ . . . :
TRAILL (T. W.), Buileti, Land and
Marin
TURNER (Thoa.), Iron and Sted,
WELLS (9. H.}, EngineeriDg Drawing
andlkerigD
WKiGHT (Dr. Alder), The Threafaold
of Science,
Oils and Fat^ Soapa and Candlea,
TEAB-BOOK of Beientiflc SocietJM,
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miSSTiriO AND TXCHSOLOaiOAl, WOSKB. 3
THE DESIGN OF STRUCTURES:
A Pnurtliwl Tr»Ktla» on the BuUdlnr of »ilili««. Roofia, &«.
By S. ANGLIN, C.E.,
Uatir of EnfiDHniig, Rojil UniTcniiT of Irelud, lolc Whitwonh Scholu, lie.
With vei7 Dometoui Dkgmns, Examples, odcI Tttble*.
Lu^ Crown 8vo. Cloth, i6s.
1. It snppliM the wsnt, long felt among Stndenta of Engineering and
Aichitectai'e, of a concise Text-book on Stiuctures, requiring on the port of
the TMder a knowledge al Elementaev Mathematics oul;.
2. The subject of Graphic Statics has onlj of recent yean been gcsctollj
applied in this countiy to detennine the Stresses on Framed Structures ; and
in too many cases this is done itithout a knowledn of Che principles npon
which the science is founded. In Mr. Anglin's woik the system is explained
from nKST pbinciplks, and the Student will find In it a valuable aid in
<letemuning the iCressea on all inegularly- framed Itructutet.
3. A large nomber of Pkactical Examples, such as occur in the eretr-day
experience of (he Engineer, are given and csrefully worked oat, some being
tolved both analytically and graphically, as a guide to the Student.
4. The chapters devoted Co Che practical side of the subject, the Strength of
Joints, Punching, Drilling, Rivelting, and other processes connected with the
mannfoctare of Bridges, Roois, and Structural work generally, are the resnlt
of UANV years' EXPBKIBNCE is ihe bndee-TBrd ; ai^ Ihe infrirmaCion given
on tbi« branch of the subject will be found of great value Co the practic*!
bridge-builder.
"SCndali of EnfiiKttiDc will find lliu Tut-BodiiH
"The juithor bu certamlT lucceeded in ivoduciDi
LONDON: EXETER STREET, STRANDi
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4 OBABLMS OUmtr * 00.'a FUBLtOA TIONS.
ASSAYING (A Text-Book of):
For tht VM 0/ Student; Mine Maniigm-; Aaiayart, do.
By C. BERINGER, F.C.S.,
iMt CUcfAjHTo' lo i^ lUs TinW Cafpa Coafaj, Loadsa,
And J. J. BERINGER, F.I.C.. F.C.S.,
PbUk Aul]nt ror, ud LkOdw Is Ibt Miouc AjKcioliM of. Csn*^
Wilb Dttmerau Table* and lUmtmioDi. Crowa Sro. Qoth, 10/6.
&(Vm/ Ediiitm; Rerued.
GmnAi. Coxmrn Pabt I. — Ihthoductoit : Mjikifulatiok : S»mJing;
Diyug ; Cikoluiga ol Ramlt*— I^bonloiT-bDolu und Rcporu. Mithom : Dry Dnn-
: Wm GnTiBMric— VoluHDic Ahuti: TLiramcmc, CalonmFirii:. <
'-i| wid Mlanirinr Prufmli Frj-mnlir Trfiiiilinni \r- 'iiirrifir <7t-
T II.— MrrAuTDcleclIoaud AiuTof Silvtr, Gold, PLuinum. Mir
biUuB, Biuuitku AntiiDuiT, Inn. NkJicI, Ccibdi, Zinc, Cadmium, T
D, MaocucH, OmniuDi, ftc— EJUthi, ADulia.
PHOTOGRAPHY:
ITS HtSTOHY, PROCESSES, APPARATUS, AKD MATERIALS,
Comprltlng Worldng Details gf all the Uore Important Hethods.
Bv A. BROTHERS, F.R.A.S.
WIT// TWErfrr-FOUE full pace plates bv many of the pro-
cesses DESCRIBED, AND ILLUSTRATIONS IN THE TEXT.
I» Am, HattJsenu Ctotk. Priti iSi.
General Contents. — Part. I. Introductory — Historical
Sketch; Chemistry and Optics of Photography; Artificial Light —
Part II. Photographic Processes.— Part III. Apparatus.— Part IV.
Materials. — Part v.- — Applications of Photography ; Practical Hints.
ajqMTiebce in Pbotofnphj «> lurfe uhI vfttied tbat tar *ariE
uiu ud yiliubls. ... A u»t cauruHusivi yoIbiik,
njtCTIULKIHTSaRorailUTVALUK . . . kAtuMAj t!H'iV''—Brit.ft'ir.tfPlMtrr»fkt.
" for the llluMnciani doni, ihs book it nou uKcmtinc ; but, ipui froa ihoc, the
taluua u vmJiuble, bnghdj ud plcuunly wriLten. uid HOST ADMIKABLV AIIUiKUD."^
PlulffTB^Iiit Nrmi.
"CcruinlT ibc riNKT rt-LumuTan haiiiik»ic u PtiatosTapti]; which W cnr bcea
pablbhcd. Should h« on Lha nlerenca ihdTH of ercry Phoiogrvphic Soat^.'^—Ammtrwr
to ohuio ■ copT •> ■ reference worh.~— /-.lirvn^^ f<^
'*The coHPLKTDT HAHDiooic of the ut which hu yet been publuhed." — Saiimam.
LONDON; EXETER STREET, STRAND.
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SOIBNTIFIO AND TSCHNOLOQICAL WORKS. s
MrNE-SURVEYING (A Text-Book of):
For tiM uu of Mwtagon of Minaa and Collitrlet, Student*
at the RoyaJ School of Mine*, ite. .
By BENNETT H. BROUGH, F.G.S.,
Lull lutnicloc of Mina-SurvcyiDg, RaT>l School at Hisa.
With Ditfiami. FnCKTR EDirioK. Crown Svo. doth, 71. 6d.
General Contents.
Gemro] Explanationi — McasureriMnt of Distances — Miner's Dud — Varialion of
the Magnelic-Needle — Snrveying with the Magnetic-Needle in presence of Iron —
Surreying vriih the Fixed Needle — German Dial — Theodolite— Traveraioc Undo-
Ifrotind-iurface-Surveys "with Theodolite— Plotting the Survey— Calci^tioD of
Areas — Levelliiw — Connection of Underground- and Suiface-Surrej's — Measuring
Distances by Telescope — Selting-out — Mine-Surveying Problems — Mine Plant —
Applications of Magnetic-Needle in Mining — -App&idicts.
*'lt ii the kind of book which hafl Idd^ heen niiled, uid no Ejij[luh-iKHkuif Miae Afeal
or MiniDC Sluden twill consider hi» technical ILbtary complete without iL' — A'dfwv.
TVOEKS
By WALTER R. BROWNE, M.A., M. iNST. C.E.,
I«W FcUow of TrinitT CoUeje, Cunlindc*.
THE STUDENT'S MECHANICS:
An IntrodactloB to the Study of Force and Motion.
With DiactMni. Crown Svo. Cloth, 4*. M.
" Ckir In itTle mid (noici] in method, ' Thi Studiht'* MscKainci ' ii ocidtillT to be
ifomimmHpd from MllpoiBti of view. "—..^Mjjfjii—.
FOUNDATIONS OF MECHANICS.
Papen reprinted from the Engimttr. In Crown Svo, 11.
FUEL AND WATER:
A Manual for UB«ra or Steam and WetAP.
Bt Pior. SCHWACKHOFER and W. R. BROWNE, KLA. [See p. 38)..
LONDON : EXETER STREET, STRAND.
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« 0BAULM8 eJUFrm * OO.'a fUBLWATIONS.
PRACTICAL GEOLOGY
(AIDS IN):
WITH A SECTION ON PAL^OffTOLOGr.
G RENVILLE A. J. COLE, F. G.S.,
PnloHr of GwilccT ia ihf Roral CoUaic ef SdieacB be Irdud.
Second Edition, Revised. With IHustratioas. Cloth. los. 6d.
OEHKRAL OOHTBNTa— PART I.-Samplino of tkb EABTtfs
Cbvst, part 11.— Examination of Miniiau. PART IIL — Exakuu-
TiOM o» Rocks. PART IV.— Examination of Fossils.
" PnC Cole tmti at the euniiiulion sr miuenli ud rod:! in ■ mj cliBt has aero-
been ailemptnl before . . . □eshtii'S or the highest piaise. Here indeed are
' Aids ' jKKUKaEABLK And IKVALITA^LE Al] the directioiu are giren with tbe utmcm dear-
1UH Aiut predlioa.** — AAtiHtiaK.
"To the youniei worken in Geal«nr, Pntf. Cole'i book tlU be u iHoisPMitKAaiji u a
djctioniiry to ine Icamcrt of a languue." — SatmrJaj Rrvinr,
"That the voric dcKrvei JB liile, that it ii nill ot 'Aids,' and in the bJKheat degi^
■ PEACTICAL,' will be Ihe veidict of all wbouie a.'—Natitrt.
"A KOIT vALUAiLi and welcome book . . . Ihe nibject ii Ircated «■ Enes whoOr
different from thnee in any othet Manual, and 11 thcnforc very oucihal." — SdtiKt G*tti*,
" A more uiefiil work for the practical eeoLofist hai noc appeared in handy (baa. —
" '"Thii DCELLEKT i3aNUAL . . . wDl be A TEUT CSKAT K«I,P. . . . The ICCtU
OB the Exaniination of FouUi it probably Ihe lEST of iu kind yel published. . . . Fml.
of well-digateil infonnatum bom the neweii aoureo and ftom penonal rcaeardi. "— j« ■■■ fc
*fN^. HUltry.
SANITARY RULES AND TABLES:
A Pocket-book of Data and General Information useful to Munioipal
Engineers, Surveyors, Sanitary AuVioritiea, Medical Officerm of
Health, and Sanitary Inepeetort.
By W. SANTO CRIMP, M.Inst.C.E.,
AUD Ch. H. cooper, A.M.LC.E,
MINING ARITHMETIC AND CALCULATIONS:
A Handbook for Mine and GolUeiy Uanageia and othan
ongaged la PraoUcal Work.
Bv JOHN CUTHBERTSON,
Lecnii« on Uinbg to the Ayrshire County CoaDctl.
Id Ciovrn Sra
{Griffin's Mining Snies.
lX)NDON: EXETER STREET, STRAND.
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aoimsTino asi> TwoasoLmwAt wommb.
SEWAGE DISPOSAL WORKSi
A Qnide to the Construction of Works for the Prerontion of t&e
Pollution by Sewage of Rivers and Estuaries.
W. SANTO CRIMP, M.Inst.CE,, F.G.S.,
Lit
With T&bles, lUmtia
Skohd Edition, Revised and Enlarged. 30s.
DeuUiofRlnrPdUullDiiiuirl R«oi
PART L— iMTKODUCrOET.
S<ttlu( Tuki.
Hourly ud D1U7 Flov of Scwace.
Ills Plil SriUD u ASecting Scnn
The S^wuioo of RuoHnRi bu lEe Sci
The PreiantkHi ol
T^JcofS
PART II.— SeWACB DlSPOSAl. WOKKS IN Ot-EKATION— THKIB
Construction, Maintenance, and Con.
lUnstraUd by Plate* showing the General Plan and AiTBn{[emat adopted
Map Df At LOKDOM Sew
Cnuueu OuIfilL
>oydc^
InigKtiiiD Fum, Borau|h at
HcFtoiL Cmdon fCunJ Suuott Authoritj'
SmDincl^ Derbyihin,
The Ediug Sewxgs Works.
KuEUgo-cm-Thuius, A, B. C Piscoi.
StlfoRl Sew^e WukL
Niw l^eri,'"auni
SmaJl Fitlcn.
ActiHi. Fenngne lad Polaiiie Praeoi.
Ilford, ChidvcU, ud Daienbim "Viakt-
CoreDtry-
BinuuifhuL.
MuTEate.
PortflDMUllL
BERLIN Sewage Fan
ORKS of EagLuti .
workipf of «ch. ■
.ween ue didemiB tf
" ProbiblT th*
in our Imfui^e- - . . Will prove of ..._ , .
Sevife DdpoAl to face." — Edinbttrx^ MtdicMt/ovtttiU.
»Jis, the chipler oe
' fratitude tg Mr. Crimp. . .
TfKB ud Ihor advuen ■ -
ru and dekOiptioDt of HAMV OF Tl
rhe canEully-iK^Bjed dzawiaci pi
* IS ■ll'^ho hi
K ineiKd
IXnmON : EXBTER STREET, STRAHD.
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8 OBARLMS OSIfrilf * OO.'B PUBLICATJONB.
CROMPTON (R. E., V.P.InstE.E., M.InstC.E.):
DYNAMOS (A Practical TreaCiie on). With numerous Illustrations.
In Laige Svo.
^VOKK S
By J. R. AINSWORTH DAVIS, B.A.,
nioratsos or bkhxmt, urnvKuiir collwh. abut>twttii.
DAVIS (Prof. Ainsworth): BIOLOGY {An Ele-
mcDtBiy Text-Book of). In Uree Crown Svo, Cloth. SECOND Edition.
Pakt L VBorrABTx Moipboloct ahd Piitsioi.ogt. With Complete Indei-
Clonaiy and isB lllustrationi. Price 81. 6d.
PAIT IL AltnuL MoBPHOLOGT AND PHTSlOLOor. With Complete Indei-
Gtoswj Emd 108 lUtistratHHU. Price 10s. 6d.
EACH PART SOCD SEPARATELY.
*,* NOT8— The Second Edition has been thoroughly Revised and Enlaifed,
and includea all the leading- selected TYPES in ihc various Organic Groupi.
"Cenainlr tha bkut 'aidlocv' wiOi which ve an acquainted. It owe* \t% prc-
emipence to ine focT th«i jE it m ixckllimt atiempt co pceKPt Biology la the Student ai a
toMKLATMU *ND ionPi.«Ta sciKKCa. ThegloMsriii ladc ii 1 host umtdl additim."-
fbirB."— Smtitr^* Srt/irat.
DAVIS (Prof. Ainsworth): THE FLOWERING
PLANT, OS Illustrating the First Principles of BoUny. IjUfie Crown
Sto, with numerous Illustrations. 3s. 6d. Sbcohd Edition.
" It would b« luTd In find ■ Teii-haoL which would betur |uidc ihe sodcDi to an acnmu
knowledge of inodtoi diKoierieiin Boiany. . . . The sclaifTiric AceuM '
the chapter on th« PhytloloEy of Flowen, an mdmiro^t Hrmmi LajeiirtEi, drawn froin Danvia,
DAVIS and SELENKA: A ZOOLOGICAL
POCICET-BOOK.) Or, Synopsis of Animal Classification. Compriong
Definitions of the Phyla, Classes, and Orders, with Explanatory Remarks
and Tables. By I>r. Emil Seleoka, Professor in the University of
Erlangen; Aulhoriied English transjation ftom the Third Gennan
Edition. In Small Post Sto, Inlcileaved for the use of Students. Limp
Covert, 4s.
• " Dr. Selenka'i Muual will bet found utefol bj- all Studeaa of ZoologT'
the aoinial wsiid"— £a!i*. Mi£jrtiniml.
" Win nnivB rerj lerviceable to thou who are aueadiag Kology Lectoi^L -
kuale and clear.** — Lmmett.
LONDON: EXETEK STREET, STRAND.
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BOrSKTIFia AND TXOSirOLOaiCAL WORN. 9
GAS, OIL, AND AIR ENGINES
(A Practical Text - Book on Intaraal Combustion Motors
witbout Boiler).
By BRYAN DONKIN, M.Inst.C.E.
■\Viih numerous IHuslrations. I^iEe 8vo, lis.
.— Ou Kndnm:— GcHnl D«cripti«i— Hituitr ud Dnelop-
■i German Gai Engin«-G» Producf'— '~ "-■ - »
Theorr of 'he Gxi Engine— Chemicxl Campontion a( Cu in Gu Enginn— UtiLiuIion a
Hcni— EiplOMOn anii CoBibuiiian. Oil KotOra :— Hiuoiy and Devtiopiuiit— Vuioui
Typei-Fneitman'i vid other Oil 'Engins. Hot-Alp Bnsfnu ;-HUtory ud Develop
ment— Vuioui Typa : SliiUng'i, Ericuon'i, fie, &c
"Tlu BBT ■ooiE HDV FUBLtsHED on Gu, Oil.BDd Air Enginei. . . . Mr. Donkin'i
book vill be of vijiv givat ihthbst to the numerous pActicAl enftnecTi who tuw tc
make theBuelvei fenuUnr wiib the motor or the day. ... He hu the advuiti^ ol loni
TBACTICAL EXrEJIZlN€ll» combined with high ^CIKHTIFIC AKD RXPKKIHIhTAL ItHOWLUlCB
■aduiaccome peroe^oa of Ibe rtqainmenls of Engtueeri.* — Tht Engtnttr.
"TheiateUicenceihitMr. Bryan Domcik haipublUhediTeil-bBok ihould be cooi
feod we welcomed it at Am aight ai being juit tbe liind of book for vhicb everybody inter
uted ID the aubject hai been looking, . . . We HXAHTrLV mkomhihd Ur. Ehukin':
wodc. . . . AmoDumeuorcanfullabaur. . . . Luminoui
Notbing of any impoiunce acemi to bave hna tjailteA^'—ZttimMl p/du L^tiiig^
INORGANIC CHEMISTRY (A Short Manual of).
By a. DUPRfi, Ph.D., F.R.S, AND WILSON HAKE,
rb.D, P.I.C. F.CS., of the WeHmiiulv Hotpilal Uodical SchooL
Second Edition, Reriied. Crown 8to. Cloth, 71. 66.
"AweH-wriuei^ dearand aeeunig ElcmtiusT Umiialof InoiguiicaMniMrT. ■ ■ .
We agree beaniJr tn the lyatem adopted by Dra. Dupri and Hakb Will icAira Emu-
MUTTAl. WOIK TIULV tHTUHTIHC HCAUU IHTILUCI ■LS."-^lUta>Wiv JCmlntU
Ihfl remaiDder coinea afterwarda id him in a manner much mofe alfflple and Buiij acquiffd.
Sdcnce crvrr the fragamtary ityle K> graerally followed. Bv a lomo way tub um of lb*
twa Uamiali for Studenia.'-.4ru/j>((.
HINTS ON THE PRESERVATION OF FISH,
IN RBFBRENCB TO FOOD SUPPI-Y.
By J. COSSAR EWART. M.D., F.R.S.E.,
RegimPnlMdrafNaninlHkloiT, UnmiB
In Crown Svo. Wn^pcr, fid.
LONDON: EXETER STREET, STRAND.
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aaARLEs oMirFiir * 00:8 puslioatioitb.
Second Edition, ^etnn£ XfyalSw. IVitk nuuuitm IBmarMitm amd
13 LtthografUc Ftata. Handsmu CUth. Prict yts.
BRIDGE-CONSTRUCTION
(A PRACTICAL TREATISE ON) :
Bring a Text-Book on the ConatnictiOB of Bridges ia
Iron and BteeL
FOR THE USE OF STUDEHTS, DRAUGHTSMEN, AND ENGINEERS.
T. CUVXTON FIDLER, M. INST. C.E.,
Pnl of EDfiiiHriai. Ulunnitr College, Dumd**.
!s ariaei from the combioation of kipibIERCi tuid
ilisplaj-ed on every p»g«. . . . Theory is kept in
■ubordinUioD to practice, and hia itoak is. thereEore, u uwful to gicdai-mwen
u to rtudentB of Briage Construction."— (rA* "JrrAiieci" on Out Svond
Edition.)
" Of tftta yean the AmericBQ treatioea on Practical and Applied Uechanica
liave taken the lead . . . aiace the openiDg up of a vait contineat haa
given the Amerioan eosineer a namber of new bridga-probUma to solve
. . . bnt we look to the PRiBEin Tbbatisb os BBiDOB-CoHsntconoti, and
the Forth Bridge, to bring u* to the front again."— £viM«r.
" One of the vxaT BnT HiCKNT WORKS on tlie Strength of Material! and ita
uipUoMion to BridgB-Conitruction. . . . W«U npay* a oarefol Study. "—
AupMtring.
HANDBOOK for the practical Enginaer. ' — Hattm.
" An admirable acoonnt of the theory and proceaa of bridge-deaigiii AT ONCi
sctUTiric AHD THOKOuaKLT FBACTICAL. It u a book inch M We have » right
to expect from one who is himielf a Bubatantial contributor to the theory of
the inl^ect, ai well ai a bridge-builder of reput«."-^alunfay Beviao.
"Thii book ii a model of what an engineering treatiae ought to be."—
/nijujtrtea
"A Bcnainno THiATin ot OBIat iaBa.''—Wmtmintter Seeiae.
"Of reoaat text-boi^ on anlqaota of metdiUiiaal aoiouw. there baa
appeared no one more A2LK, UBAuenvx, or usktul than Mr. Claxtm
ndlcr'i work on BridgeK^natmction.'— jiiotnnaii.
LONDON: EXETER STREET, STRAJrt).
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aCIElTTIFIO ArrO TSCSNOLOCtlOAL WOSKB. ii
ORE &, STONE MINING.
Bv C. LE NEVE FOSTER, D.Sc, F.R.S.,
In La^e 8vo. With Fiooiispicce and 716 Illusliations. 34s.
" Dr. Foiler'i book w» cipicUd [0 be iitKH-UAifiHa. ud 1[ (uLIf justific* nicb up«-
■CHOWK HtHUIALS. ProblbllF Ittuull UHlllVALLID[o[COmplc»neH.'— T'^JfwiVf ?nimi/.
GENERAL CONTENTS.
INTBODUCTION. Kode Of Oceumnoa of Hlnerkls : ClwificBtiim: Tibolu-
Uepiaits, Haata— Eiunplet: Alum, Amber, Aniimanv, Anenic. Atlmtos, Ajphall,
BuytM, Banx, Boric Acid. Carbomc Acid. CUy, Cobalt On, Copper On, Uiunoudi,
t'lint, Frewfane, Uold Ore. Uraphite, Qypgum, lea. Iron Ore. Ltkd Ore, MausDcae
Ore, Mici, Natural »u, NitriLU of Soda, Oxobente, Fetroleum. rhuphate ofLime
PoUuium Salu, Qaioksilver Ore, SaJt, Silver Ore. Slate. Sulphur, Tin Ore, Zinc Ore
- Faulla. PPoapectlnKi Cliance Diaooveri**— Advenlilious Find*— (ieology as t.
Quids to Uinarali— Anociattd Mineral*— Surface Indieationa. BoFlnK: IJaea oT
Bore^bolea— Method! of BorioK Hola: I. By Rotslioa. II. By Peicunlon with Bodh
III. By Pereunion witb Hope. BroaldDK Ground : Hand Toob— Machinery—
Transmiuion of Power— Eicavatins Machinery: 1. Steam Dif;gen, II. Dredga,
in. Kock Drills, IV, Machine. forCutlinic Grooic, V. Machina tor Tunnelling-
Modei of uaina Hol»-Driving and Sinking— Fire.MttiDg—E»cavaIin(| by Water,
Supporting SxoavatloDs; Timbering— Ma»nry— Metallic SupporU— Watertight
Liniiige— Special Pnuoeea. ExploitsUon: Open Worlu :— Hydmulic Mining—
EicaiatioD of Miuenla under Water— Katnctiun of Hinenla 1^ Well* and Bot»-
hole»— UndsivrouDd H orkings— B>^>— Veina— MaiMS. Haulace OP Truuport:
UDdersroUDd: by Shoot*, Pipea, Penoni, Sledge*, Vehicla, Uailwayi, Maohiaer; —
ConTeyanea by Boat*— Above Gnund. HolStlnK 01* Winding: Molon, Drumi,aiid
Pulley Frame*— Ropea. Oh^ni, and Altadunent*— B«cepuclaa— Otho- AppllaDoee—
Safely ApplunceB— Testing Kopei— Pneamatic Uuiuing, Dral]l«8« ! Surlace Water
— Dam>— Dtainaca Tunnel*— Siphon* — Winding Machinery —Pumping Ifngine*
abone graund— Pumping Engine* bdoo gniund— Co,operaIite Pumiring. VoutllB-
tlon: Atnioepliera ol Minea-Cauan of Pollution of Air— Natural Ventilation—
ArtiHcial Ventilation: I. Pnraacs Ventilation, II. Mechanical Ventilation-TFiting
the Quality of Air— Meaauring the Quantity and Preaaui* of the Air^Bfficiency of
Ventilating Appliaoceg— Reatatance caused by Friction. LJKbtlns: KeOected
Dajlighl-Ca.,dle.-Torcbe.~Umpa-Well, LIgbt-Satety Laropa-Gaa-Kleclrio
Lilglit. Descant and Ascent : Stepa and Slides— Laddrra—Buckeu and Cages—
Han Engine. Dpesslns: I, Mechanical Procesees: Washing, Hand FicEing,
Bieaking Up. CiHuolidat.on, Soreenlng-Il. Vhyiical Prooeuei : Motion in Water,
Motion in Air— UMieeatlon— Liquefaction sod DiMillati on -Magnetic Attraction—
III. Cbemical Proeeaaei; Solution, tivsporatioo and CcysUUiiation, Atmoapberic
Weathering, Calcination Cementation, AmalganiBtion- Application of Proceaaw—
Loaa in Dreaung— Sampling, PplnelplM of Employnienl, of HtniOK Labour:
P^ent by Time, Meaiure, or Weight- By Uombination of thaw.- Value of Product.
Legislation ajrectlng Mines and Quarries : Ownenhip— Taxation— Working
»....i..in.„,_MelaIliferoua Mine* Regulati™ *-' — i^—' "■ — if-~..i.ti™ «,-i—
Ot&r B
— Alkali Aota — Boiler £xph»ona Acta— Brine Pumping A
Act*— Employeta' Liability Act— Eiplo*ives Act— Faci
and Workihop Acts-Quarry Fencing ___. _ . .
Btannaries Aol—Truck Acta. Condition of the HiDfiP: Clothing— Housing-
Education— Si ckoeia— Thrift- Recreation. Aeeldents : Death Rate of Miner* ^m
AccidentiH- Relative Accident Mortality UndFrground and Abori^niund— Claaifica-
, AdmiraMy illunnUcd."— A»^ unJ HaUmmUmmltckr Z-
,ww -oax."— Oiilfrr. 2lic*r/(. /Sr Birt- rmd JtlUUmettti.
LONDON; EXETER STREET. STRAND.
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I > asABLMa OBirriK * 00:8 fubuoa tions.
Cloth, foi Office luc, 81. 6d. Lealhn, Ita the Pocket, 8*. 6d.
GRIFFIN'S ELECTRICAL PRICE-BOOK.
FOB THB USa OF
Eleetrloal, Civil, Karlne, and Borough EncflneeFS, Local
Authorities, Anhlteets, Ballwar Contractors, &«., fte.
H. J. DOWSING,
MrmUrmftki InitilmtiM tfEl^Mcul Enti-utTi : tfHuSttirlri/Arli: i/tlULtmJm
a]lNllRA.L OONTBNT&
Past I,— PRICES AND DETAII^ OF MACHINERY AND APPARATUS.
Past 11.— USEFUL INFORMATION CONCERNING THE SUPPLY OF
ELECTRICAL ENliRUY; Complete Estimates; Reports, Rules and R^u-
Ulions, Uieful Tables, &c. ; and CenerBl Informaiian regarding tbe carryinc out
of Electrical Wwk.
"The EucTiiirAL Piici-Book huovm «tt. MrSTHT about Ihc com dT Electiica]
" -■•...- nihil »iu be enBikd by uiiluing rleoricity on a large or
« of £lectricily is being considered. "—
GRIFFIN (John Joseph, F.CS.) :
CHEMICAL RECREATIONS: A Popokr Maotu .,
Chemutry. With 540 En^nTJiip of Appanto*. Tattk Edititit. CrowM
Svo. Cloth. Complete in one Tohmie, cloth, £ilt topt 13/6,
Put L— Elementuy Cheniuli7, !/•
Part II.— The Chemistry of the Non-Hetillic Elementt, 10/6.
GURDEN (Richard Lloyd, Authorised Surveyor
fbr the Gorenmenli of Mew South Wtile* tutd Victoiia) :
TRAVERSE TABLES : comonted to Foni Places Decimals foi every
Minnte erf' An(cle ap to too of Distance. For the nte of Snireyors ai^
Engioeeit. Third EUtivn. Folio, itroogly half-bound, si/.
%* FnilitJitfi vnlk CtuMTraia of tk^ SurvtynGtmr^ ftr Nem JlmH
Waia and Vuttria.
'"nun who tun wipaneiice iniuct Suanr-waiK will twit kwnrbnrlaappncuM
dM *«mious ameunt of labour reprcKiited by this t«1uable book. Tlw prnnriiiBtwiia
4Hibb Ihe user to ■■rfpsin the lioei >ad coeines for a diataacc of twelve oilaa to wiihis
half u inch, ud this by aKnUHOi To aUT Omi Tabla in place of (he usual nfteta
■iiniu cmputaBau requind. Thii alDcieli endenceoflhe assutanceiriuczlitlieTjiblH
lAaaiv to cmrY oset, ud as every Surveyor in acrive prmctice has fab the want of sack
aaHscaae^ lew knowiiic of their publicauon will msaid wubnnt LhBm." — Rngmnr^
LONDON: EXETER STRETT, STRAND.
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aaiMNTiria akd TaosyoLooioAL woasa. n
Griffin's Standard Publications
EHGIHEEB8, ELECTBICIAHB, ABCHITECT5, BUILDEBS,
NAVAL C0H8TBUCTOB8, AND fiUBVETOBS.
PAfil
Applied Heohanlos. ■ Kakkini, Browkx, Jawksok, 22, 5
16
CItU EnglneeFliig, .
Pbof. Bankini,
22
Brldg»-Constructlon, .
Prof. Fidlbb, .
10
Design of Stpuotures, ■
S. Arglin, .
3
Sewage Disposal Works,
Sasto Crimp, .
7
Traverse Tables, ■
B. L. OURDEN, .
13
Marine Englneerl^,
A. K Seaton, .
29
Stability of Ships,
Sib E. J. Be8i>,
21
The Steam-Engrlne, .
Banedib, Jauikbok,
22
,16
Dynamos.
B. E. Croupton,
6
Gas, Oil, and Air-Englnes,
Brtah Donein,
9
Boiler Construction,
T. W. Traill, ,
30
.. Hanasrement,
E. D. MoHKO, .
18
Fuel and Water (for
r SOBWACEHOFZR AKD
I Browne,
}
28
Steam Users),
Machinery and Millworlc,
Prof. Eamkime,
22
Hydraulic Machinery. ■
Prof. BoBiKSOir,
26
Hetallui^cal Machinery,
H. C. JENKIN8,
25
Useful Rules and Tables
f Profs. Bancihb ass
1 jAHIEgOir,
[
22
for Engineers, &&. .
Electrieal Pocket-Book,
MOBRO AMD JaHIBSOH
19
Electrieal Price-Book, .
H. J. DowBwa, .
12
Graphic Tables for Con-
28
Marine Eiurineers' Pocket-
Book
S BATON AND RonNTBWA
TK,
29
Mystrom's Poeket-Book,
19
Surveyors' Pocket-Book,
Crimp and Cooper,
7
LONDON : EXETER STREET, STRAND.
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14 oaASLBB Bairrttr * oo:s ptrSLiCATioirs.
In Large 8tw, wUh liitatntiuns and Feldtitg-Plates. lor. 6d.
BLASTING:
A Hindbook for tha Use of Engineers &nd others Engaged in
Mining, Tunnalling, Quarrying, &c.
By OSCAR GUTTMA.NN, Assoc M. Inst. C.K
J er' CtBi! Extiiutrt •md A nkitaU tf CuMW aMd Btubtftll,
nitr^tlu Imf.Sti/.CtalaricaiIiHHtMlinf/AMilrU, At.
't BiAMiim£ ii the Dif LV VDrit on the lul^ecl whict ^irct At ooor fiiU
HKTHOH adopied iiac( the biniiluaiol of DynnniR. wd. U lb*
^MMQ uBK, uKmkiii~ vp haky viau rvAtn-jctL KkPHRiiHCK both in HiiuDg WorkaAd jb
lh« Mmnubciiirc of EiploavK. It thmTore pruenti in OMCuc Tona >U Ihu hu beD>ntwi^
■Dad is [he vuioui mohodi of pncedure. Tht lUuurMKHU rotm i •pecnl ud vmliiaUe
Baturr of ihc vorit.
General Contents,— Historical Sketch— Glutuig Materials— BUsting Pow-
der— Various Powder- mimures— Gun -coiion — Nilio^ycerine and DjTianiite —
Other NilnMXimpounda — Sprengel's Liauid (acid) Eiploiives— Other Meant of
Blasting— Qualities, Dangeis, and Handling of Ei plosives— Choice of Blasting
Materials — Apparatus Tor Measuring Force — Blasting in Fierr Mines — Means of
Isniung Charges — Prepuation or Blasts — Bcoe-holes — Machiae-drillini — Chamber
Mines— Charging of Bore-holes— Deiermi nation of the Charge— Blasting in Bore-
holes—Firing— Straw and Fuie Firing— Electrical Firing— Substitutes for Electrical
Firing — Results of Working — Various Blasting Operations — Quarrying — Blasting
Masotity, Iron and Wooden Structures — Blasting in earth, under water, of ice, ^
"Thii ADUiiuata mik."— CfttfiT Cixn<i«.
'* Should prove a vmdr-mtcum to UuiLd|[ EDgiDevrt and all eiigiLB«d in pracckal vork."
■—Irtm and Ltal Trada Rftllnm.
With Numerous Illustrations. Price laj. &d.
PAINTERS' COLOURS, OILS, AND VARNISBES:
A. JPractical IVIaJiual.
By GEORGE H. HURST. F.C.S.,
Manber of lh« Society of Chemiial lodujlry ; Leclurer on the Ttchnology of Painters'
ColDiin, OiU, and Vamiihet, ihe Municipal Techniui School, Muchaui-
General Contents.— Introductory— The CourosiTioN, Manufacture,
Assay, and Analysis of While Pigments— Red Pigments— Ydk>w and Orange
[dements — Green Pigments— Blue Pigments — Brown Pigments — Blade Pigments
—LAKES — Colour and Pami Machinery— Paint Vehicles (Oils, Turpentine, &c.,
4c )— Driers— Vaenishks.
"This useful book mixt aucceufnlly comlHiietThBiry and Prutice ■ - . will pmirc
•loiT VALUABLE- Wt feel bound lo recDmineBd it to ALi. ehgafted in the iirti eoncerned."—
CMtmialNmt.
'* Kfratticat manual in every respect. The directions are concLie, clearly inlellinble.
and axciuiiiiSLV miTaiicTiva. Tlie aectino on Vaniiihcs cha mos leaKoable «c bave
met with-"— C,4n>Bi«/ and Drvgitl.
" A work (bal U bath uiefuT and nacetsiry. from the pen af ■ wiiler exporienaed in iootb
wayi ibiiB OK wiih the very wide nibject with which he deali. Very valuaile iifonna-
tion it ^Ica'—PltiHihtt and Draimttr.
" A TKoaoucHLY MtACTicAi. hoolt, . . . conatilitlint, we believe, the dklv Eniliab
work that laiUadarLly treats of the manufacture of oils, colours, and pifrnents.'— C^AMvi
Tradif yau-i^.
" Thtouahont the woik are ictltcred hinti which art mVALDABLi to the iBlefflgeu
reader. ■■—/•OBiniw.
LONDON: EXETER STREET, STRAND.
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SaiMUXIFIO AND TMCBHOLOaiOAL WORKS. ' 15
COAL-MINING (A Text-Book of):
HERBERT WILLIAM HUGHES, F.G.S.,
AwK. tUr/mi Sdwd nf Minci, Cnobaial CoIHeit Mi»im.
Second Edition. Jh Demy 8™, Handsamt ClatA. Wilk ptry Numervm
IQuitratietu, nwitly ndiKidfrom Werking DrcomHgi. \%t.
"Tbe details of callieiT work have been folly described, on the fiound that
than b]' bold strokes of engineeiins, . . , ll frequently happens, in paiticuLar
localities, that the adoption of a combination of small improvements, any of
which viewed separately may be of apparently JLttle value, lums an unprofitable
concern into a paying wx." —Extract from Aulkur't Prrfate.
OBHBRAL COKTBNTS.
irr o( Succcuian— Cu-bmiiferoiil Syitnn !n BriOuB.
if Ceil— Clauifiatian and Commeitial Vila* vf Ccoli.
gf dtep Borins— Sp*
mleau— AccMcnU ii
Toob—l^asBiuHwii
Ooal! fiotioK— varioui appltanccs UEed^DevicH Fmplayed to
" ' ■ -■ ■ -• Borinj— Mall " — ■■■■ *
rnelhod* of Boring— Mulwr ft Platt't, A
KocndwE ■Jtenvuil^-LlpinE ihifti— Kh^^ °sgi #u« by TabUnfi-^CHt of TobHoc—
Sinkiii|[by Bgring— ICiDd-CluudrDii, mud Ljpmonn melhodt — £Hd]ung throuah OuickAUHU
— Coil of Siaking. pMliioUikij OpanMlBBi : Drivinc undetEmuid Roadi^DpponiDE
Roof: TimbcriiiCi Cbocki or Cofi, Iron 11111 Steel SupsoRi mi Mawaiy— AnMiatiiKiil S
lata, MMhoda of WorUllg : Shaft, Fillar, and Subiidence— Bord and Filial Snlen—
Lucaihire Helhod— Lounnll Mtlhod— DouUa Soil MMhod—WoiUBs Sta» Shdu—
WorluDE Thidi Seami— Working Seanu lying Dear lagetlier— SponUoeoui Combuilion.
Hanlaas: Kiili— Tubi— H>DlaE« by Hono— Seltictiiig Inclins— Diiwl-aciiDg Hiulajn
—Main and Tail Kope— Endlcu Chain-- EadleH Kopt—ConpaiUoD. WlnilBg: Fil
Fnines— Pulleyi— Ca|;ct— Ropei — Guidei'-Eiiginei— Dnim»-.-Bxakea— Counterbolanciiie —
Expansion — CondcDHUoi^— ConpoDDd £ii^n€i— Prflventioa of Ovarwinding — CaLchea at pit
— "'- '-- Tubg— Tub CamrDllen— SiKnalHiil PIUnplll|: Bucket and FluDjer
^oa^uu— Liwi of F^aioB— Pndueti
, and Fan*— Diuiibuiioii of Ike Ali-cuimU— Mcanuwent ol
cvrROU. Xdlhtlllt: Nakad Lighu — Safety Lampi'- Modem lAoipi
Locking and Cwuiiiig Lampa— £lactiic laght Underxrouiid — Delicate 1-*'
aX tax^Bt; BoUen-^ecbanical Slaking— Coal Coavevon— Woikib
j-Tynodlll _ ..
1— Coal Washing— Dry Coal Oearung -BriqneOBk
hI with tbe actual working of cotlietiei. The illuiintHnu
"Mr. HuGHEi hai Ind oppottuuitlei for study aad n
STANDAiD woaK of in kind. '— A'rj^fiiriaM Dallj G<urltr7
VJVi'Cr.— The lint largo edition of this work wai eihan
publication.
LONDON: EXETER STREET, STRAND.
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i6 CHABLMa OBirrm * oca fOBLtOATIOSg.
WOBKB BT
ANDREW JAMIESON, M.Inst.C.E, M.I.E.E.. F.R.aE,
PROFESSOR JAHIESOH'B ADVANCED MAHUALS.
I» Largt Crmm 8(«. FtUly lUiutrattd,
\. STEAM AND STEAM-ENGINES (A Text-Book on).
For the Use of Sludenls i
With over 300 Illustrations, FoIdiiig''Plates, tiA Examlna
Ninth Edition. Revised and Enlarged, 8/6.
^ PrttcKor JamicmaQ &Kiiulem the xuds br tuB CLEAKHnB o' Cf»
IPLECLTV OF UFHSUOK. Hil txtaUDCDt RcUll Ulc t«ctunnc of Fmrwixy."'^
" T)ie Bnr Boon yd publiihcd for the uh of SnHluitt.''~£iynuirr.
" UndOubledlr ihe UIHT VALUAILI AMD UOIT COHFLzn Hud-booll
kl-book a
2. MAGNETISM AND ELECTRICITY (An Advanced Text-
Book on). Specially arranged foi Advanced and " Honours " Students.
8. APPLIED MECHANICS (An Advanced Text-Book os)^
Specially arranged for Advanced and " Honours " Students.
FBOFEBSOE JilUIESON'S INTBODDCTOBT HAHSALS.
In Crvwn 8iv, ClulA. fVili very Humermii IlUtairatietu and
ExamiiutUH Fafers.
1. STEAM AND THE STEAM-ENGINE (ElementatT Text-
Book on]. Specially nrranged for First-Year Students. ThiU
Edition. 3/6.
■■ Quiu Ihe IlbHT U»T or ■OOK."— f ivi'-<rr.
"SLould be Ld :he haadfl of availT CDgiiieeriiig app»DIice.*' — Praiiicai El^inttr-
2. MAGNETISM AND ELECTRICITY (Elementary Text-
"A THOKOLTGHLV TRUETWOnTHr TuE-bcxjlf. , . . ArTanRnacDt Ml fonl u ^
can be. . . . Dugraiiu ire alio «cr)l«nt. . . ■ The lubjeci tkraufhixil tralnl is
esieatildly Hactical one, and vrry dor iBUniclioni pyen."—ii/alllrt.
3. APPLIED MECHANICS (Elementary Text-Book on).
Specially arranged for First- Year Students. 3/6.
" Nothing ii taken for jmoied. . . . The work hu vmv high qualftiiSi •*''''
my be candenKd iolo the one word ' ci-xi.^' "Scltnci and Art.
A POCKET-BOOK of ELECTRICAL RULES and TABLES.
FOR THE USE OF SLBCTR/CIANS AND ENGrNEEKS.
Pocket Size. Leather, Sl 6d. Ttnlk EdUion, revised and ea^uffA.
(See onder Mtairt ami jamiaon, ]
LONDON I EXETER STREET, STRAND.
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SCIBKTinO AlTD TBOBSOLOOIOAL WOSKB.
(Din. iro*i an DraliiE that bu yst aiiMm] )n Iha BncHib
TUB Stud^u) WoiK or BsnusoK tor 3»i% (o sams."—
In Two Large 8yo Volumes, 920
pp.. with a SnPPLEMENTABY
Volume, eontahilng Specimens
of Dyed Fabrics. Handsome
Cloth, 45s.
MANUAL OF DYEING:
FOR THE USE OF PRACTICAL DYERS, MANUFACTUREftS, STUDENTS,
AHD ALL INTERESTED IN THE ART OF DYEINQ.
CHB. BAWSOK, F.I.C., F.C.5.,
And BICHARD LOEWENTHAL, Ph.D.
Ostrstui, CoNT«Nm,— Ubemie*! Technology of the Textile Fftbrica—
Witer —Washing and Bleaching — Acids, AlkalieB, Mordftoti —Natural
Colouring Matters — ArtiGciol Ortiaiiic Colouring Matters — Mineml Colour*
— Machiaarynsed in Dyeing- Tinctorial Properties of Colonring Matten —
AiMtysU and Valuation of Mat«[iaLi uaed in Dyeing, Ac, Ac.
■'ThiB M0« TALCABLE K
" TUi wttaoritiilra ud
on the aubjein.'— nzilM J/i
" Tb> HOii ixBtusrivi uid ooKrtRi won on iba inbjaet eitut'—nztM Ai
"ThsdldUngalihedaaUianhaTspliuiedlnthelundaoC thoH diilj an^i^ la th* dye-
boo*B or UboratoTT ■ work ot Birnm value ud ciDoranD utd-ht . . . >pp«*lB
qnloUr to the lechoologttt, ooloor chamlit, drar. End mora putlealErl* to the riElu drar
or the present ^nentlaiL A taook whLofa It ]■ rafnihlnc to uaei vlth.'^— .J
ikwhlohllll
LOKIX>Nt EXSTER STREETT, STRAND.
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|8 aSARLBS OBlFFiy * 00.3 PUBIdCATIOSS,
ELECTRO-METALLURGY (A Treatise on):
KnbrBcIng the AppUotion of Eledmlyiu to the Pktjng, D^odting,
Smelting, Mid Kefinin^ ot vuiooe Metala, And to the Bepro-
dnction of Printing Snr&oei nd Art-Work, fc^
Br WALTER G. M'MILLAIT, F.IO., F.C.S.,
^MOmUirn <■ XMf'' OMif, Lmttm.
With nniiMTOiu Illiutntiani. Lerge Crown Sro. Cloth, 10b. 6d.
Grobal CohtEHtS.— IntrodnctOTT — Senron of Csmnt— Genanl Conditioa
to be obwnad in Electro-Pliting—Pliting A^Jnncti uti DiipostiDn of Plmt—
Claaaiuig ud Pnpkntion of Wm^ for th* Depoevmig-Vu, and Subeeqnait Poliahmg
of PLkMd Oaod<— Elsctro-DcpoBtion of CspHr— ra«treti>^ng— E]ecIn>-Depositi<a
cf tiil?«r — of Gold — of Hickal ud Cobalt — of Iron — of Pluumni, Zinc, Cumioin,
Tb, Lud, AobnoDT, ud Biamath; filecCro-chromj— Electn-Depcation of Alloja—
Bleotro-lIotaUiiif^a] Extrictian and fiefinmg ProccsH — Racxmiy of ortain
Hetala from their Soln^oa or Wula Snbatancei— Detamtinatioii ef tlie Propoiliaa
ef Hatal in oenuu DepoiltinK Solatioiu— AppCLdiz.
' ' This eioelteot treatiae, . . . one of the ttxT ani Hon ooio-lbts
DwankU hitherto poblUhed on Electro-Metallurg;." — BUetriiMl Renae,
" Thia work will be a aTiHBASD. "— JnwKer.
"Any metallorgioal prooeaa whioh itinooaB the OOST of prodootiaai
Dintt ta ofloenit; prove of great commarciAl importanoe. . . . Wa
rMonunend thia uuumal to all who we iDtereited in tin PHAOnou.
ATPLtciTtON of electrolytic proceaaea."— JJoture.
BaoosD Edriok. ShUargad, atid vtry/nUf iBiutralad. OotA, it. U.
STEAM - BOILERS:
THEIR DEFECTS, MANAO-EHENT, AHD CONSTHUCTION.
Bt R D. MUNRO,
Eagimtr tfO* SeMUk BMtr Imtunaiee and EKgia* In^teUm Otnpmqi.
Thia work, written chiefly to meet the wants of MechaDioi, Eogine-
k««pets, and Boiler-fttt«nd*nta, aleo oontaina inforauttaon of tk« fint iin]M)rt-
ance to every uaer of Steun-power. It la a nticiioiL work writtMi for fxac-
7IC1L men, the language and nilea being throughout of the aimpleat natnr*.
" A vklaable compkoion for workmen and engineen engaged abont Steam
Bdlera, ought to becarefaUyatadied, and alwatb at SAin>.'''— CoU. €hiatdia».
" The Bubjeeta referred to are handled in a tmitwoiihy. clear, and pnobdal
mannar. . . The book ia tbrt conrL, eepetaallr to ateam lueiB,
artiaaoa, and young engineen."— fnirmwr.
BV THB SAMB AtTTHOB.
KITCHEN BOILER EXPLOSIONS: Why
Ihey Occur, and How to Prevent their Occurrence? A Piaclical Hand-
book. With Diagcams and Coloured Plate. [^/ /^vt.
LONDON : EXSHER STREET, STRAND.
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SOieSTTIFIC AND TBOHNOLOQIOAL WORKS. 19
MUNBO k JAMIEBOH'S ELECTRICAL POCKET-BOOK.
Tenth Editioh, Revbed and Enlatged.
A POCKET-BOOK
or
ELECTRICAL RULES & TABLES
FOR THS USB OP ELECTRICIANS AND ENCfNEERS.
BY
}OHN MUNRO, C.E., k Tsar. JAMIESON, H.Inst.C.E., F.R.S.K.
With Ntmieious DiE^jianu. Pocket Sue. Leathci, Si. 6d.
aitHEItA,L OONTBKTEL
Units of Measukement. I ELBCTEO-MBTALLUitGY.
M us [IKES. I BATimmts.
TlSTlNG. I DVNAHOS AND MOTORS.
CONDUCTOKS. I TRANSFORUBRS.
DiBLBCTRics. Electric LicuTina
SUBUAKiNE Cables. Miscellaneous.
Telecrafhv. I Logarithms.
Electro- Chemistry. I Appendices.
y/anhj of the higbeu o
> Hud jAumwH*! PocEET-BoaK.'—
MUNRO (J. M. H., D.Sc. Professor of Chemistry,
Downton CoU^e of Agriculture):
AGRICULTURAL CHEMISTRY AND ANALYSIS: A Prac-
tical Hasd-Book for the Use of Agricultural Students.
NYSTROM'S POCKET-BOOK OF MECHANICS
AND ENGINEERING. Revised and Corrected by W. Dennis Marks,
Ph.B., C,E. (VALE S.s.s.}, \Vbimey Professor of Dynamical Engineering,
University of Pencsylvsnia. Pocket Siie. Leather, 15s. Twehtutb
Edition, Rsviied and gnUly enlaced.
LONDON ! EXETER STREET, STRAND.
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30 OBABLsa aurrm a oo:b publwatiowb.
Detny Svo, HandtamB eiloth, 18*.
Physical Geology and PalMtology,
OJ^ THE BASIS OF PHILLIPS.
vt
HARRY GOVIER SEELEY, F.R-S,
VUtb frontlBplece in Cbromo-Xltbogtapbe, and }{[u0tiatfon8.
■ DiRBCTOBY to the Student in prosecuting hU reseirches," — PrttuUntiai Ad'
draitsdu Gali^Uai Seeidy,li&l,by RrB.Pref.Bttmty, D.Sc,LL.D., F.R.S.
"PaonssoK Sbbliv maintuiu in his ' Physical Geology ' ^le h^
Rpatktioa he ilreidv deservedlj bean u > Teacher." — Dr. HtHty W»od-
vard, F.R.S., itt Iht " Cttlogital Magannt."
" PionssoK Sibley's work indadet ooe of the uoit ntii&urtory TreatiMs
OB I.itfa(^0C7 in the Engliih lut^uge. ... So much that a not acceisilie
ia otha works il presented in U)is TOlunl^ that no Stadat of Geok^ can
«flbrd to be withoat it." — Amtrieau Jetimai iff Eitgmetrmg.
Denvy Svo, ScmdsoTn* eloth, S4>-
Stratigraplilcal Geology & Palaeontology,
0}f THE BASIS OF FEILLIPS.
BY
ROBERT ETHERIDGE, F.R.S,
am T>B NATUSAL KtsT. DitpAK-muiT. ■■msH uusauK. LAIS rtumoimuocai m ma
CauLOCICAL SUKVBT Or CMUT ■HITAIH. FAn nuimXT Of T)U
VUtb Aap, nuRieioue lEabtes, mb ZbMs-eit putes.
XT ELABOKATI
fvw/d ttlhtltt
tf Cmtegf tK Bt iiain — may tt had em affikatum ta Vu fliiluluri.
•," TtxariCTVia e/ tie aiaoeimfiirrtattfntri—fittAifii tie KOsitLABO^JiTK^
" *' ' '" t,andfiucaiaiiaiedlegivianewitren^l9 Iktitm^
' : — nay tt had em affikatum ta Vu fliiluluri.
.Bpol koowLcdfc hfti mr been UtKight logcthp bafar^'^
If TcmArkiblfl faricioricidalityuMl th»bnailtlkflfib*i«*^
. ^ , TUidtliibmdtliefil. ,
iiUy jutdiin the UHrden mwle in hu pnliice tint hu book diflm is am-
il from UT knon inwuuL • . . UoM oka biob iahk ahcok) wcnn
LONDON: EXETER STREET, STRAND.
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BOIMSTIWW ASD TJKSSOLOQICAL WORKB. 31
Third Edihos. Rtvitd by Mr. H. Bauenaan, F.G.S.
ELEMENTS OF METALLURGY:
A PRACTICAL TREATISE ON THE ART OF EXTRACTINC METALS
FROM THEIR ORES.
Br ARTHUR J. PHILLIPS, M.Inst.O.K, F.C.S., F.G.S., ic.
And H. BAUERMAN, V.P.G.S.
aXNERAI. CONTENTS.
Bcfrsctor; Matniali. I Antimon j. i Iron.
Fjre-CUTB. Anraiic. I CDtwlt.
FneK_ 40. "■ '
AlamiDiiim.
Copper.
Meromy.
BiamutD,
" Of tbe Thibd Eiution, we am still abla (o say that, u % Text-book of
Metallurgy, it " '«« bsst W'tli which we ara ftcquainted.'— Baffin wr.
"The Tftlne of thii work is almoit iaulivtablt. There ud ba no quertion
that the amount of time and labour beatowed on it is enormoiu. , . . There
a CKiXs,va\y no Metallurgical Treatise in the language calculated tu prove ot
■ueh (renerel otility." — Minino Joursaf.
" In this mast useful and handsome volnme is condenged ■ large amount of
valuable practicd knowledge. A careful study of the firat division of the book,
on Fuels, will be found to be of great value to every one in trUDing for the
.■..! .__i7..^i ... r 'entific knowledge to any of our metallurgical
a. Hum iriilun is Hjumiy vaiiiable to the Stndent OS a Tiiit-book, and to the
practical Smelter as a standard Work of Keterence. . . . The IllnatratMae
are admirable examples of Wood Eogiaving. " — C^tnticat JITcum.
POYNTING (J. H., Sc.D., F.R.S., late Fellow
of Trinity College, Cambridge; Piofeuoi of Physics, Mason College,
Biimingham):
THE MEAN DENSITY OF THE EARTH: An Essay to
which the Adams Prize was adjiub^ in 1893 in the Universily of
Cambrii^e. In large 8vo, with Biblu^iaphy, Itlustistioos in tbe Text,
and MTcn Lithogra^ed Platei. lis. 6d.
and THOMSON: TEXT-BOOK OF
PHYSICS. {See imder 7%imMfi).
LONDON; EXETER STREET, STRAND.
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OBAttLaS QBIWriS S OO.'S PUBLIOATJOya
WORKS BY
W. J. lACQDORN RANKINE, LL.D., F.R.S.,
Ltli Htflat Proftttor at Clull Englm&trinf In tki UninnfU i^ QltafiiK.
THOBODOHLT WEVISm Wt
■W. J. MILLAR, C.E.,
Stcrttvy tt Ot liatltutt of Englimrt ami SHIpHulUtn In Scetlmi.
I. A MANUAL OF APPLIED MECHANICS :
CommiunK the Principles of Stittics uid Cinematica, mud Theory of
■atructurea, MechuiiBm, uid Mochinu. With Nnmaroni Diaf^aiiu.
Croirn Svo, cloth, Itb. 6d. Thibtkknth EDmoH.
II. A nANUAL OF CIVIL ENGINEERING :
Oompriiiiiit EngiDoerinc; Survey*, Earthwork, FoiindatioDt, Muoarj, Car-
Bintry, Metal Work, Roai" " ■ '■.■.■
krboara, Ac. With Num
cloth, 16a. Nineteenth I
III. A HANDAL OF MACHINEBY AMD HILLWORK:
Compriunf{ the Geometry, Motiona, Work, Strength, Cooatmctioii, and
Objecta of Machines, &c. Ulaatrated with nearly 300 Woodcnta.
Ctowd Svo, cloth, 12a. 6d. Sixth Editioh.
IV. A MANUAL OF THE STEAH-ENGINE AND OTHEB
PRIME HOVERS :
V. USEFUL RULES AKD TABLES :
For Architect!, Builders, Bngi&eerH, Fonndera, Mechanica, Shipbuilders,
Snrveyon, Ac. With Arpitmix for the use of Elxotbical Ehoihxsbs.
By Frofetaor Jauixson, F.U.S.E. Seve-vth Edition. 10b. 6d.
VI. A MECHANICAL TEXT-BOOK:
A Practical and Simple IntrodnctioD
" ' " INK and E. F. Bai __ , _
n Svo, doth, 9b. Fodrth Editiof.
t (bripMd *ii ProtMsor SAnun at at UTa»-
LONDON: EXETER STREET, STRAND.
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BoiBSTsria AVD TaasNoioaicAL woaxa. 33
psor. RAMEnn's WoKu— (C:Hi<MMwrf).
Tn. MISCELLANEOUS SCIENTIFIC PAPERS.
Rojral 8to. Cbth, 31s. Sd.
P»rt I. Pbpen relating to Tempentnre, EIuiticitT, ind Eipanrion of
Vftponn, Liquids, and Solids. Part II. Papers on Energy and ita Traui-
formationi. Part III. Papers on Wave-Fonni, PropQlsion ol Veasela, &c.
With Memoir by Fcofattor Tait, M.A. Edited by W. J. Miu«u, GE.
With fine Portrait on 3teel, Plate*, and Diftgruns.
" No Don endurui^ Memonal of Profeflctr Ranldne could be devtied thu the pabfiiB-
REDGRAVE (Gilbert R.. Assoc. Inst. C.E.):
CALCAREOUS CEMENTS: Their Nalute, Preparation, and Usm,
writh some observations on Cement Testing. A Practical Hand-Book.
(GriffiH'i Ttthnelagical Manuals). [At Frai.
I=Ea?E/OXiETT:M::
A Treatise on the Geographleal Distribution, Oeolo^eal
OcGurrenee, Chemistry, Production, and Reflnlng of
PetPOlenm; Its Testing, Transport, and Storage,
and the Legislative Enactments relating
thereto ; together with a description
of the Shale Oil Industry,
BOVERTON REDWOOD, F.R.S.K, F.I.O., Assoc. Inbt. C.£
Hon. Carr. Il*m. af M* Imptrlnl BmmIm TmAnlaal Baelita i Ham. of
till Amarlcm Chtmleal Seclaty; Coiaultlng Adoliir in (A>
GEO. T. HOLLOWAY, P.I.C, A.RC.Sc.
In Large 8vo. With Maps and Illustrations. [A/ Pusi.
•.• Sficul FitTUBB of Ur. BinirDOD's Wotk us (t> the hllharto flopabSitod d*-
■CTipiloDi Of the UvDivvLOFiD SotricKB Of PiTmoLnw In nrlom v^m ot the worlds whlob
'the SDthorli In ui exceptlau&kJT fLTOimble poeltloe to fife; And rf} Baloi for ths TunMO,
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X4 OBAaiss eurrty a oo.'s PUBLiCATiosa.
THE STABILITY OF SHIPS.
SIR EDWARD J. REED, K.CB., F.RS., M.P.,
ma tmmtma JUiutraHgm amJ railts.
a b*ai wntta Ist tb* pmpciM «f vbwliic in tb* hMoii d Nanl Cgndnictm.
, .OSccn of the Ro]rdudUBCulikMuiBa,ud all StnilaiualNinl Sauce,
■ ceaptiu TnMu* upon ibg SubilitT of Siift, ud b lb* oilr nrii in tat Entfab
I ■inii»i:» dcaliaf nh«n«ivdy with tbe nilijcct.
!• firder to rtui«r Ihc woHe eDuplcM Cor thd r*"r^**t «f tb« SlupboDdo', whether K
biJMi or ibniail, (he Helhsdi of CJculuioa iatiodiictd br Mr. F. E. BAImt, Mr. GitAir,
U. RnCH, U. Datuud, uil Ur. Bhjahth, in all given lepuuehr, iUainUKl b7
T*Um Vkd wariud-cut exempiea. Tb« book *''**'*^*'* more thaa boo DUfTuni, %aA n
Blutrmtad by a large numbeT of acrtua] caiaa, derived from iJupt of all dcacTJ ''
^pKullTlrai*bi|i>Df the MeriAiilile Mariae.
The worit will thiu be round to coutitute tbe noit osaprebcDiive and oitbuud
UdwRo jmented to ihe Prafeu^ini on the Science of iba Stahutv or Smr*.
" Sir Edwaid B(U>') ' STAmiurr of Skifi ' ii iitTAi.iiAiu. In it ibe Stuumi, arm
to tib* nHoclt wilt find the path prepared tor hun, and all dificultiem explained with tiba
mmatttn aaduxuncy: the SKip-tiiuucHniiAK will find all the mtlbodi of alculatioa M
prvHt in uc AiHt crpUined and iUusmtod. and acnnnpanied br the Tablea and Forw
CBfleyed : the SHimirHn will find the varUiiona in the SlaliiUiy of Sliipa dna to dilTervDCia
in ina and dimonsou full/ diicuiied, and the devices by which the lUIe of hit ibipe under
aB eonditlm may be ttaiJneally te;n ii iiled and eaJly undentood: the Naval AicHiTacr
vil find hfought tofctner and nadv to hia hand, a maia of inlbnnation which he would other*
wits have to tceli in na abnoat endleaa variety of puhlicationi^ aiKl aona of wbkh b* would
poaaibl]! nai be able ta ofaoin at all -'—'—-" 'ft 'rj*
"ThiaiKPDilTAHT AHDVALUABLIWDiK . . . cannot bc too highly
RICHMOND (H. Droop, F.C.S., Chemist to the
Aylesbury Daiiy Company] ;
DAIRV CHEMISTRY FOR DAIRY MANAGERS : A Pradicd
Hmndbook. {CrigMs TecAnolegual MaimaU.)
LONDON: EXETER STREET, STRAND.
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aaONTIFIO AVD TaOHNOLOOKAL WOBKB. 3$
Griffin's Sff*teUuiS>taI Sitms.
STANDARD WORKS OF REFERENCE
FOB
■etallnrglsts, Mine-Owners, Assayers, Hanufaotorers,
and all Interested In the development of
tbe HetaUuTfTio&l Indiutries.
EDITED BT
W. C. ROBERTS-AUSTEN,, C.B., F.R.S.,
NoTW Ready.
L IlTTBODUCTIOir to the STUDY of ttETALLUEGY.
By the Editok. Third Edition. 121. 6d.
" No Ea(^iib text-book at alt ■.pproacbes thii in the comfletehesb with
vfhich the most modem views on the subject are dealt with. Professor Austen'fl
vobune will be invaluable, not onlr to tbe student, but also to those whose
knowledge of the art is far advauoed."— Cicnica/ A>ui.
" lyvALUABLE to the studenL . . . Rich in nutter not to be readily fouod
elsewhere. " — AtAtnmai,
" This volume amply realises Ibe expectations fonoed as to the result of Ibe
labours of so eminent an authority. It is remarkable for its OltiOJNALITY of con-
ceptioD and for tbe large amount of information which it contains. . . . We
recommend every one who desires information not only to consult, but 10 STUDY
this work." — Engiiutrmg.
•• WTill at once lake fhokt rank as a teit-book. ■— 5^««« and Art.
" Prof. RoBEBTS-AusTEH's book marks an ^locb in tbe history of the teaching
of metallurgy in this country." — Indusirits.
a. OOIiD (The Metalliirs7 of>. By Thos. Kirke Rose,
Assoc. R.S.M., F.I.C., ofthe Koyal Mini. 21s. (Seep. 27).
Wia it PuiiuAeJ at SkiiH Inlirpmh.
3. COFPEB (The Hetallui^y of). By Thos. Gibb, Assoc
R.S.M.,F.I.C.,F.C.S.
4. UtOir and STEEIi (Tbe MetaUurgf of). By Thos.
Turner, Assoc. R.S.M., F.I.C., F.C.S.
8. UETAIjIjUBOICAI. MACHXHTEBY: the Application of
Engineering to Metallurgical Problems. By Henry Ckarles Jenkins,
Wh.Sc., Assoc. R,S.M., Assoc.M.Inst.C.E,, ofthe Royal Mint.
6. ALLOYS. By the Editok.
*,* Other Volumes in Preponlion.
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l6 OBARLM OMimir A tfft.V PUBUCATtONB,
aSOOT^D EDITIOJi. Bevised and Enlarged.
In Large 8vo, Handsome cloth, 34t.
HYDRAULIC POWER
jun>
HYDRAULIC MACHINERY.
BX
HENRY ROBINSON, M. Inst. CE, F.GS,
king's coluo, btc, ctc
unitb numeioiu TOoottcuts, and Sfits-itfne plates.
Cenerax. Contents.
DUchu^ through Orifica— Gannng Wiit«r by Wdrs — Flow of Wuer
tlitoosh Pipes — The AecumuUtoi — The Flow of Solids — Hydraulic Ptcssb
■Dd Lifts — CfdoDC Hydnulk Baliiw Press — Anderton Hydnulic .
Hydraulic Hoists {Ufts)~Thc Otis fcJevator— Mersey Ratlwty Lilts — City
. and South London Railway Ijfts— North Hudson County Railway Elevator-
Lifts for Subways — Hydraulic Ram — Pearsall's Hydraulic Engine — Pmnpinc-
Engines— Three- Cylinder Engines— Brotbtrbood Engine^Rige's Hydiaulu;
Engine — Hydraulic Capstans— Hydraulic TriTersers — Movable^igger Hoisl—
Hydraulic Wo^on Drop — Hydraulic Jack — Duclibam's WeighingHacliiiie —
Shop Tools— Tweddell's Hydraulic Rivelter — Hydraulic Jo^ling Pies —
Tweddell's Punching and Shearing Machine— Flanging Machine — Hydraulic
Centre Ctane — Wrightson's Balance Crane — Hydraulic Power at the Forth
Bridge — Cranes — Hydraulic Coal -Discharging Machines — Hydraulic Drill —
Hydraulic Manhole Cutler— Hydraulic Drill at St. Gothard Turutel— Moton
with Variable Power — Hydraulic Machinery on Boanl Ship— Hydraulic Points
and CrossinBS^IIydraulic Hie Driver- — Hydraulic Pile Screwing Apparatus —
Hydraulic Eicavalor— Ball's Pump Dredger — Hydraulic Power applied to
Bridges — Dock-gate Machinery — Hydraulic Brake— Hydraulic Power applied
to Gunnery — Centrifugal Pomps — Water Wheel* — Turbines—let Propnlsion —
The Gerard-Bair^ H^raulic Railway-^Creathead's Injector Hydranl — Snell's
Hydraulic Transport System — Greatbeail'a Shield — Grain Elevator at Frank-
tjTt — Packing — Power Co-operation— Hull Hydraulic Power Company —
London Hydraulic Power Company — Birmingham Hydraulic Power System
—Niagara Falls— Cost of Hydraulic Power— Meters— Schtoheyder's "
Regulator — Deacon's Waste-Water Metet.
" A Book of (Tcat ProfdHoial UBtulrHd."— /nm.
*v* Tbe SaocDfii Edition of tbfi 4bovA Importaut
brought ap to dLto, Mkdt new fol]-'-"-'- ™-."
hmnsHd tiota U In the FIral EdiUi
daanrlpUon of Ifae FliVi. nuf )» liad i
LONDON: EXETER STREET, STRAND.
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SOiaNTUia AND TtOENOLOaZOAL WORKS. 3]
OBIF7IIT'8 UETAI.I.UBGICAL SERIES.
THE METAUDR6Y OF GOLD,
T. KIRKE ROSE, B.Sc., A.R.S.M., F.C.S.,
AuittOMt Auayar of the Rogol Mint.
luBOB 8vo, Bahssohb Clotk, Illustratid. 21b.
LEADING FEATURES.
L Adapted for all wbo are interested in tlis Gold Mining InduEti7, being
imt fmm teohDioalities ttiar aa poniible ; of apecinl value to thoae engaged in
the industiy — viz., mill-manage™, reduction-offioBrs, 4c.
2. Tbe whole ground implied bjthe term " Metallurg7 oE Gold" has been
covered with equal care ; the ipace ii carefally apportioned to the varibiu
branches of the subject, according to their relative importahce.
3. Hie MacAbtbl'r-Forbebt Ctanide Process U fully described for the
fiiBt time. By this process over £2,000,(100 of gold per amium (at the rate of) is
now being extracted, or nearly one-tenth of the total world's production. The
procesH, introduced in 1887, has only had ehort newspaper accounte given of it
previouBly. The obaptere have been submitted to, anil revised by, Mr.
MacArthuT, and so freed from all pOBsible inaccuraciee.
4. Among other new processes not previonaly described in a text-hook are —
(1) The modem barrel chlorination process, practised with great success in
Dakota, where the Black Hills district is undei^ing rapid development owing
to its introduction. (2) New proceases for separating gold from silver— viz., tbe
new Gntzkow process, and the Electrolytic process ; the cost of separation is
iediie«d by fliem by one-half.
5. A now feature is the dnoription of bxaot mbthods employed in particular
extraction works — 3tamp-batteriei of South Africa, Australia, New Zealand,
California, Colorado, and Dakota ; Chlorination works also, in many parts of
tbe world : Cyanide works of S. AMca and New Zealand. These acconnts lie
of special valne to practical men.
6. The bibliography is the £nt made since 1882.
"Xr, Bosk gaJnAdhls eiperienca la lbs Wssiern States of America, bat he baa seenred
lo pmcUeal BiBO. . . . TOBroiifob»p»r»onC'AtorirmWoii,WTltten from Itui polntot view
■lllie ol tbe praoUcaL man and ths ahemiai. Tini with cDmuRunom aimuro UKsacwi
"Tbenio(tcDmplgiadeKripUai>ortlis<!li]arJntt10D process uhlch has 7«t bean pnbBihed.
LONDCai: EXXTER STREET, STRAIOX
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CaABLSt OBIFFIN A CO.'S PUBLICATtOtTS.
SCHWACKHOFER and BROWNE:
FUEL AND WATER: A Uuiul for Um t^ Stom and Water.
By ProC FRANZ SCHWACKHOFER of Vienm, ind WALTER
R. BROWNE, M.A., C.E., Ute F«llo<ri>rTruuIr CoUcec, CMiibridge.
Dcmj 8n>, with Nnmeroni llluitimtioiii, 9/.
GmaAL CoKTaim — Km wd CamboBkn— Fnl, Virietica of—Firinc Arucb-
iHnu: Fuman, Fluu, ChimiKT ~ The Boiler, Okucc ef— Vuietici — Fml-ntci'
Hautn-Stcu Pipe*— Wu« : Conpoiition, Furifkatioa—PRTemiDnsf Scale, Ac, gtc
"Tlw SectioB oa Heat iimc oFthcbcM ud nwct lucii] erer wtiltia."— Ji^mui .
"CuBolfiiltolMnliisUtutbouiudi Dtinti ttain pairer.*—Xm Ah^ £i>/flwir.
SEXTON (Humboldt, F.I.C., F.C.S., F.R.S.E.,
Prof, of Meullnrey, Gla^ow and West of Scotland Technical Coltcec) r
( Ei.EMENT/.KV Manual of). With numtrous
o, extra. [Al Press.
OUTLINES OF QUANTITATIVE ANALYSIS. For the Use t£
Students. With Illustrations. Foukth EiiinoN. Crown 8vo, Cloth, 3s.
A (ood and UKfiil bc^— /.unt.
OUTLINES OF QUALITATIVE ANALYSIS. For the Use of
Students. With Illuslrations. Third Edition. Crown Sto, Cloth, 3s. 6d.
"Tbe wotkeCi Ihonuchly pnctical littaitt'—BriHiiittdiailJun'wai.
" CsBpUed with inat can, aDd will wpptr ■ saat-'—ywriH/^^riteaMM.
SHELTON-BEY (W. Vincent, Foreman to the
Imperial Ottonuui Gnn Factories, ConxCantiDople) 1
THE MECHANIC'S GUIDE: A Hand-Book for EnEiuen and
Artizan*. With Copious Tables and Valuable Redpe* for Fnctical Uib
lUustrated. Stctnd EdUUn. Crown Svo. Qotb, 7/6.
SMITH (Robert H., M.Inst.Mech.E., Prof, of
EnBineeiiDE, Mason Science College, Birmingham) :
GRAPHIC TABLES for the Conversion of Measukements
(English and French). 38 Diagrams for the Mutual Conversion ai
Measurements in Uiflerent Units of Lengths, Areas, Volumes,
Weights, Stresses, Densities, QtiANitTins of Work, Horse-
Powers, Tempbratubes, &c For the yse of Praciical Ei^oeen.
[Jiiarljt kia^.
LONDON: EXETER STREET, STRAND.
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BQimSTIFW AND TMOBNOLOOICAL WOMKS.
A MANUAL OF
MARINE ENGINEERING;
By A. E. SEATON, IL Inst C. E., H.Iiist.MeclLE.,
M.Iiist.N.A.
GSNERAI. COHTKNTS.
enlatloiu for Cyllsdera,
Pistons, Valves, Expansion
Valves, &C.
Part IV.— Propelleps,
Part V.—Boilers.
Part TL— Wscellaneous.
Pait n.— Principles of Steam
Engineering'.
Part UL— Details of Hailne
Engines : Design and Cal-
" In tba thi've-lald gutoitr of snabling > Student to l«un how ta dMifrn. oonMraol,
and work ft modnn Muin« Bicam- Engiiw. Mr. Hailon'i Muinal bu no utai. u
ncrnidi oomiircbimii>nwa of nurpOH and lucldiiy of trutmint."— TV— ~
" The importut lablect of Manna EnKineerins ii hen bvaWd
una that U nqnina. No deiiaftment haa cacaped attention,
lanluof mncb oloee itndy and pnctical work."— £iv<ae>Hiv.
"Uy far the Bin HiNCiL ineiiitence. . . . uItm a oDn
methods of lolTing, with the utmoat poaaible economy, the proble
Enaineer.^-'^UauaBL
''The amdmL Drmiurl
— Maria* gmgii
'*The Student, Draushteman. and Engineer will flnd tfall work the aoR TILOABLB
HiHDBOOK at Refannaa on the Marine KnjiiDa ni " '
Secoks Editioh. With Dikgruna. Pock«t-Sit«, Leather. %a. 6d.
A POCKET-BOOK OF
MARINE ENGINEERING REES AND TABLES,
Superintendents and Otners.
A. E. SEATON, M.I.C.E., M.LMech.K, M.I.N.A.,
AMD
H. M. ROTJSTHWAITB, M.I.Moch.E., M.I.IT.A.
"AntiKABLT rvLnu iu |iupoH.'''-J/*rw Eituutr.
LONDON: EXETER STREET, STRAND.
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y> OBAMLMS OMims S OO.'B PUBUOATIOira,
By PROFESSORS J. J. THOMSON k POYMTIHQ.
In Luge 8vo. Fully lUnitrated.
A TEXT-BOOK OF PHYSIOS:
COHPRISDia
PR0PSRTIB8 or MATTER; BEAT; SOUND AND LIGHT;
MAGNETISM AND ELSCTRICITT.
VI
J. H. POTNTIHG, J. J. THOMSOK,
im or TriBiu CfliiHE. cuiMdA: p»L
BOILERS, MARINE AND LAND:
THEIR CONSTRUCTION AND STRENGTH.
A Handbook or Rous, Forndi^ Tablu, kc., rxl4tivx to Matesul,
SCANTUNOa, AND PRBaSITKn, SAFKTT VAI.VB, SfBIKQB,
FiTTcas AMD MoTrnnMOB, led.
yoc tbe tUBc of air stann-iOseta.
Bt T. W. TRAILL, M.Isbt.O.E., F.KRN.,
nctlHF e<UT(7ar-lD-Chlaf to Ik* Baud o[ TniU.
tonm. .'.'.' th—t wild hiiB Id irmlia ioUtn irtll Dnd thil (hcj no hUI* Iba cUmeni
^twapfMf with •Imort BO tulimiilon wllh lu iJd. ... A mob lum tu
mpvl^M nronutioa w be hu sowhn ebo. — Jw Av^Haer.
" Ai k kudbook ot nin, ftmiato, UUa, *&, nlittlar to lutalili. kuUId(i. ud pt
IT tlUDL TbB Buna or the Author li t niffldtnt nuruloi for U> ■
n ■ THt UKOBt or ald^Uon,-— /'
inorilKnUeet. .
LONDON : EXETER STREET, STRAND.
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BOIMNTIFIC AND TtCSNOLOaiOAL WOBKB. 31
WORKS BT DR. ALDEB WMSHT, r.B.8.
FIXED OILS, FATS, BOTTERS, AND WAXES:
THEIR PltXPAKAVIOK A3XT> PROPBRTIES,
And tlu Xannfiuttsre therefrom of Caadlei, Soapi, aod
Otber Frodnet*.
C R. ALDER WRIGHT, D.Sc, F.R.S.,
Idle Lecturer on Chuniitry, St. Muy'i HoepiuU School; EouniDetiji "Soap'' to tbv
G(7 md Guilds of London Institvle.
In Luge 8n>, Handsome Cloth. With 144 lUnalrfttioni. i8g.
"Dr. WncHT'a «tli will be fmied ausolutei-v i»DisPEKS*iii.e by creij Chemist.
TiBllt Willi infonulioa nluaUe alike to the Annlyit ud the Techaial Ouxium.'—
Ttr Ana/ylt
"WiU nwk mi the Standakd Ehguih Autkoiiity od Oils ud Fats tor many
yttn to coau.'—lnduitTin and Inm.
THE THRESHOLD OF SCIENCE:
Simple and Amusing Experiments (ovep 400) in
Chemistry and Phystes.
*,* To the Niw Editioh hM been add«d aa etcellent ch&ptu on th»
8nt«m^D Order in whioh CUaa Eipsrimenti abould b« earned ont for
EdnotionBl purposes.
"Anyone who m&ystiU haie doubta regarding thevalaeat EletMlitarr
Science ss uk ornn of edncstion will speedily have his doubts dispelled, if bo
laksa tba tronble to nndcntand tha methoda recotmnended by Dr. Alder
Wright. The Additions to the New Edition will be of great service to all
who wish to uM the I'olHme, not merely as a ' play-book,' but ■« " '
for tha TXAiHiHo of the WBNTAL TioOLTiiB."— .Yalurt
" step bj step the le
ade aas;^ by the perl
FBmD of many a bright ai
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