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TRANSACTIONS 



THE FEDERATED INSTITUTION 



OP 



MINING ENGINEERS. 



VOL. V-1892-93. 



Edited by M. WALTON BROWN, Secretary. 



(£K© 

NBWCAflTLE-UPON-TyNB : PUBLISHED BY THE INSTITUTION. 

Pbinted by Andbew Rbid, Sons & Co., Newoabtlb-upon-Tynb. 

1893. 

lAU rights of publication or tramlation are reserved.'] 



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N -8.1^36 



DEC^/1907 



ADVBRTIZBMENT. 

The Institution is not responsible, as a body, for the statements, 
facts, and opinions advanced in any of its publications. 



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CONTENTS OF VOL. V. 





PAOV. 




PAQB. 


Adybbtizement 


... • ii 


List of Membebs ... 


XTii 


CONTKNTS 


... ■ iii 


HoNOBABY Membebs 


... xvU 


Bye-Laws 


X 


Membebs 


... xviii 


0FPICBB8 


xvi 


Non-Fedebated 


... xWii 



GENBBAL MBETINaS. 



Fedebated Inbtitutiok of Mining Enoinbebs. 

PAGB. 

Jpne l.—Qeneral Meeting (London) 1 

Prizes 1 

Presidential Address , 2 

Discussion ... 9 

" Spontaneous Combustion in Coal-mines.** By Joel Settle ... 10 

Discussion 18 

" Mining in New Zealand. Part III.— Coal-mining." By George 

J. Binns SI 

Discnssion 80 

" Fire-setting : the Art of Mining by Fire." By Arthur L. Collins 82 

Discussion 88 

** Notes upon a Practical Method of Ascertaining the Value or 

Price to be paid for Zinc Mineral.** By H, D. Hoekold ... 03 

June 2. — General Meeting (London) 105 

** The Correlation of the Coal-fields of Northern Franoe and 

Southern England.** By Marcel Bertrand 106 

Discussion 126 

" The Work of the Geological Survey.** By Sir Archibald Gdkie 142 

Discussion 167 

- ** Auriferous Conglomerates of the Wltwatersrandt.** By F. G. 

Shaw 169 

Discussion 177 

•* The Support of Buildings** By W. Spencer 188 

Discussion 197 

*< Rapid Traverser.** By James Henderson 199 

« On Earth Pulsations and Mine Gas.** By John Milne 208 

Discussion ^. 219 

Excursions, etc. :— 

The Westminster Electric Supply Corporation 220 

Gas Light and Coke Company 227 

Messrs. Maudslay, Sons, k, Field, Limited 230 



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IV CONTENTS. 

PAOS 

Ghbstbbfield and Midland Counties Institution of Enoinbebs. 
1893. 

April 8.— General Meeting (Sheffield) 365 

Alteration of Bules 366 

Nominations for Election of Officers 356 

Representatives on the Council of the Federated Institution of 

Mining Engineers 358 

July 1.— Annual General Meeting (Chesterfield) 443 

Report of the Council 444 

Accounts 448 

Discussion 452 

Election of Officers, 1893-94 455 

Representatives on the Council of the Federated Institution of 

Mining Engineers 455 

Presidential Address 457 

Discussion 461 

**A Safety-lamp with Standard Alcohol-flame Adjustment, for the 
Detection and Estimation of Small Percentages of Inflammable 

Gas." By A. H. Stokes 462 

Discussion 468 

•* An Improved Water-gauge.'* By A. H. Stokes 474 

Excursions, etc. : — 

Grassmoor Collieriefl 477 

Memoirs of Deceased Members 480 

Chesterfield akd Midland Counties Institution of Enginbbbs, and 

Midland Institute of Mining, Civil, and Mechanical Enginbebs. 
1893. 

April 8.— Joint Meeting (Sheffield) 359 

** Arrangements for Sinking to the Whinmoor Seam from the 
Silkstone Seam at the Tankersley Collieries.'* By W. Hoole 

Chambers 360 

Discussion 363 

'* A Combined Centre-line Appiaratus." By William Foulstone ... 364 

Discussion 366 

Discussion on Prof. F. Clowes* paper on *' A Portable Safety-lamp 
with Ordinary Oil Illuminating Flame, and Standard Hydrogen 

Flame for Accurate and Delicate Gas-testing " 867 

The Royal Commission on Royalty Rents and Way leaves ... 870 

Excursions, etc. : — 

Rotherham Main Colliery 871 



Midland Institute of Mining, Civil, and Mechanical Enginbbbs. 
1893. 

April 8.— General Meeting (Sheffield) 373 

June 24. — General Meeting (Leeds) 374 

Discussion upon Prof. F. Clowes* paper on " A Portable Safety- 
lamp with Ordinary Oil Illuminating Flame, and Standard 
Hydrogen Flame for Accurate and Delicate Gas-testing" ... 374 
Discussion upon Mr. E. Brown*s paper on ** Experiments upon 

two Guibal Fans at St. John*s Colliery, Nonnanton.** ••• 376 
Friction-clutches 378 



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CONTENTS. V 

PAOB. 

Midland Inbtitutb of Miking, Civil, and Mechanical 
1893. EiSGlNEKB&.—Cimtiniied. 

July 26.— Annual General Meeting (Barnsley) 483 

The Ck)uncir8 Annual Beport 484 

Acoounts... 486 

Discussion 488 

Classification of Members ... 488 

Election of Officers 490 

Representatiyes on the Council of the Federated Institution of 

Mining Engineers 491 

Miners* Safety-lamps 491 



NoBTH OP England Institute of Mining and Mechanical Engineers. 
1893. 

June 10.— General Meeting (Newcastle-upon-Tyne) 281 

" The Gold-bearing Veins of the Organos District, Tolima, U.S. 

Colombia." By Edward Halse 233 

Discussion 249 

•* Manometric Efficiency of Fans." By the Rev. G. M. Capell ... 252 

Discussion 265 

DiscoBsion upon Prof. F. Clowes' paper on "A Portable Safety- 
lamp, with Ordinary Oil Illuminating Flame, and Standard 
Hydrogen Flame for Accurate and Delicate Gas- testing" ... 265 
" The Choice of Coarse and Fine-crushing Machinery and Pro- 
cesses of Ore Treatment, Part III.— Silver." By A. G. Charleton 271 



NoBTH Staffoadshibb Institute of Mining and Mechanical 
1893. Snginebbs. 

Mar. 20.— General Meeting (S toke-upon-Trent) 419 

" Electric Lighting and Transmission of Power." By W. M. Mordey 420 

Discussion 422 

April lO.—General Meeting (Stoke-upon-Trent) 424 

Discussion upon Mr. E. B. Wain's paper on **The Longwall 
Method of Working as applied to Seams of Moderate Incli- 
nation in North Staffordshire " 424 

** The Lockett and Goagh Direct-acting Pump." By James Lockett 

and—Gough 431 

Discussion 432 

May 8.— General Meeting (Stoke-upon-Trent) 433 

" The Use of Petroleum, Paraffin, and other Mineral Oils Under- 
ground." By W. N. Atkinson 434 

Discussion 436 

Discussion on Messrs. Lockett and Gough's paper on *' The 
Lockett and Gough Direct-acting Pump " 489 



South Staffobdshibe and East Wobcbstebshibe Institute of 
1893. Mining Engineebs. 

April 13. — General Meeting (Birmingham) 379 

Revision of'Rules 379 

*' Notes on an Earth Explosion or * Bump * at Hamstead Colliery." 

By F. G. Meachem 381 



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VI 



CONTENTS. 



SouTfl Staffobdshibb and East Wobgbstbbshibb Ikstitutb of 
Mining ^vQnsKsaB.^Cantinued, 
1893. 
April 13.—** Engineeriog Scraps in Australian Coal-mining." By W. £. Benton 886 

Discussion ,. ... 888 

June 8. — (General Meeting (Birmingham) 390 

" Description of Mining Relics found at the Heath End Colliery " 891 
"The Spontaneous Combustion of Coal." By Herbert W. Hughes 392 

July 3. — Special General Meeting (Birmingham) 409 

Discussion upon Mr. H. W. Hughes' paper on '* The Spontaneous 

Combustion of Coal " . ... 409 

** Description of the South Dyff ryn and Abercanaid Collieries." 

By B.J. Bailey 416 



APPENDICES. 
I. — Barometer, Thermometer, etc., Readings for the Tear 1892. 
Walton Brown 



By M. 



II. — Report of the Prussian Fire-damp Commission 

II. — Scientific and Technical Enquiries 

. B. The Means and Methods of Combating Fire-damp 

I. — Recognition of Fire-damp 

II. — Mechanical or Chemical Elimination of the Gases which 

form Fire-damp 

III. — Fire-damp rendered Innocuous by Mechanical Dilution 

1. General Arrangement of the Workings — Opening up 

of the Seams, Fore-winning, and Working 

2. Ventilation of Mines 

I V. — Precautionary Measures against Explosion s 

1. General Observations 

2. Lighting of the Pit 

3. Use of Explosives 

4. With regard to Coal-dust 

5. Other Measures 

v.— Life-saving after an Explosion 

III. — Practically Applicable Conclusions and Suggestions 

1. From the Technical Point of View 

Principles to be Observed in Fiery Mines 

2. From the Legal and Cognate Points of View 

III. — Notes of Papers on the Working of Mines, Metallurgy, etc., from the 
Transactions of Foreign Societies and Foreign Publications ... 

** The Assaying of Antimony Ores." By Ad. Camot 

" Fuveau Lignite Coal-field, France." By — Oppermann 

** The Deep Adit-level in the Fuveau Lignite Coal-field, France." 

By — Domage 

*' The Valdonne Collieries (Fuveau Basin)." By L. Valla 

** Peat in Transylvania" By Georg Primics .., 

" Italian Fossil Fuels." By P. Toso 

** The Boleo Copper-mines, Mexico." By Edouard Saladin 

*The Copper Region of Michigan." By F. B. Phelps 

** The Underground Fire at the Lake Superior Mine, Ispheming, 
Michigan." By J. Parke Channing 



493 

500 
600 
600 
500 

504 
607 

608 
614 
535 
536 
687 
589 
543 
544 
645 
547 
547 
547 
552 

655 
555 
555 

567 
557 
559 
560 
661 
663 

663 



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CONTENTS. Vii 

P'AQK 

Appendices.— Continued, 
III. — Notes of Papers on the Working of Mines, Metidlurgy, etc. — Continued, 
" Ontbursts of Carbonic Acid Gkts at the Rochebelle Collieries^ 

France." By 0. Lange 564 

*< Origin and Distribution of Gold and Platinum, North Coast 

Beaches, New South Wales." By J. W. Archibald 566 

« The Mount Morgan Mine, Queensland" By T. A. Rickard ... 565 

" Infusorial Earth." By G. Petit 567 

** Jade in Upper Burma" By Fritz Noetling 567 

"Improvements in Copper Smelting." By E. D. Peters, Jud. ... 667 

" Manganese in the United States." By R. A. F. Penrose, Jun. ... 567 

. '* The.RusseU Process at the Sombrerete Mill." By E. H. Russell 668 
** The Practical Chlorination of Gold-ores, and the Precipitation 

of Gold from Solution." By John E. Bothwell 670 

•* The Chlorination of Gold-ores." By J. H. Burfeind 571 

« Lead-ores of Mazarr6n, Spain." Bj ¥, B. Villasante ... ... 672 

" Mica Mines of Carolina, U.S.A." By C. Hanford Henderson ... 573 
" The Magnetic Ore-concentration Works at Maiem, Tirol." By 

Josef BUlek • ... 574 

"The Conkling Magnetic Ore-concentrator." By F. H. McDowell 576 

** Magnetic Concentration of Iron-ore." By Harvey S. Chase ... 676 

" The Treatment of Tailings by the Llihrig System." By O. Bilharz 677 

" Maros Washing-table." By — EflE6re 578 

" Rigaud Cradle for Washing AUuvials." By — Kff^re 678 

" Castelnau System of Ore-dressing." By F. Desquiens 579 

" Recent Gold-milling Practice in Nova Scotia." By John E. 

Hardman 579 

*• Mining in Sardinia." By — de Launay ... ^ 580 

•* Mining in Sardinia." By — Marx 581 

** Ore-mining in Servia." By F. B. Pf eiffer 582 

" Mining and Metallurgy in Chili." By Ch. Vattier 683 

** Progress of the Metallurgy of Nickel." By D. Levat 685 

"The Production of Nickel." By J. H. L. Vogt 588 

" Nickel Mines of New Caledonia." By F61U Benoit 689 

" Production of Nickel in the United States." By W. R. Ingalls 590 

" The Huanchaca Mines, Bolivia." By Robert Peele, Jun. ... 691 

" Phosphates in Canada." By R. W. Ells 692 

" Phosphates in Florida, United States " :— 

(1) By Floyd B. Wilson 593 

(2) By Walter B. M. Davidson 593 

" Naphtha in Austrian Galicia." By Claudius Angermann ... 595 

"Petroleum in France." By P. Dubreuil and J. de Clercy ... 695 
"Geology of the Caucasian (Baku) Naphtha Region." ByHj. 

Sjogren 696 

" The Petroleum Industry of Baku." By A, Leproux 596 

" Naphtha in the Caucasus." Anon 599 

•* Petroleum in India": — 

(1) By R. D. Oldham 600 

(2) By Tom D. La louche 600 

0$) By Thomas H. Holland 601 

(4) By Thomas H. Holland 601 



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VUl CX)NTBNTS. 

PAUB. 

AvPEVxyiOES,— Continued. 
Ill, — Notes of Papew on the Working of Mines, Metalluigy, etc. — Continued, 

«' Petroleum in Persia." By J. de Morgan 601 

" Bafety-catch for Pump Spears." By J. Sprenger 602 

"Buraah Ruby Mines." By Fritz Noetling 603 

"Bxperiments with Safety-lamps." By the French Fire-damp 

Commission 603 

" The Cuvelier Lock for Safety-lamps.*' By Joseph Goffin ... 606 

" Relighting Safety-lamps in Collieries." By Joseph Goffin ... 607 

*' Tommasl Electric Safety-lamp." By D. Tommasi 608 

"TheWolf Benzine Safety-lamp." By P 608 

"Salt-mining in the Austrian Alps." By August Aigner 608 

" Salt Industry in Italy." By F. B 610 

" The Salt Lakes of South- Western Siberia." By R. Helmhacker 61 1 

" The Broken Hill Mines, New South Wales." By E. F. Pittman 611 

'* Drainage of Sinking Shafts : Tomson System." By A. de V. ... 612 

** The Poetsch Method of Sinking." By W. Schulz 613 

" Coal-screening in the United States," By Bckley B. Coxe ... 615 

" Miners' Changing and Wash-houses." By — Fabian 617 

•* Sulphur on Pit-heaps." By A. Cocheteux 617 

" The Sulphur-mines of Altavilla-Irpina, Italy." By W. Deecke 618 

** Machine for Shaping Mining Timber." By Alfred Mathien ... 618 

" Telethermometers." By Hans Hartl 618 

"Centrifugal Ventilators." By R. Van A. Norris 619 

IV.—" The Education of Mining Engineerd." By Prof. J. H. Merivale ... 623 

Appendix. — Educational Institutions where Courses of Study are 

provided for Mining and Metallurgical Engineers 625 

I. — Great Britain : — 

The Royal College of Science, London, with which is in- 
corporated the Royal School of Mines 625 

University College, Bristol 627 

Camborne School of Mines, Cornwall 627 

The Durham College of Science, Newcastle-upon-Tyne ... 628 

Sheffield Technical School, Sheffield 630 

The Yorkshire CoU^e, Leeds 631 

II.— Colonies :— 

Sydney Technical College, Ultimo, New South Wales ... 631 

University of Otago, Dunedin, New Zealand 632 

University of King's College, Windsor, Nova Scotia 633 

Ballarat School of Mines, Industries, and Science, University 

of Melbourne, Ballarat, Grenville County, Victoria ... 634 

Rchool of Mines and Industries, Bendigo, Victoria 636 

III. — Europe : — 

Royal School of Mines, Przbram, Bohemia 636 

Hainaut School of Mines and Industry, Mons, Belgium ... 636 
School of Arts, Manufactures, and Mines, attached to the 

University of Li^ge, Li^e, Belgium 637 

Catholic University of Louvain, Louvain, Belgium 637 

The National Higher School of Mines, Paris, France 638 

Douai Mine-overmen's School, Douai, France 638 



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OONTENTS. 



IX 



Appendices. — Continvcd. 
IV. — "The Education of Mining Engineers." — Continued, 

Baint Etienne School of Mines, Saint Etienne, Loire. Fi-ance... 639 

Berlin Royal Geological and Mining Institute, Berlin, Germany 639 

Royal Technical College, Aix-la-Chapelle, Germany 639 

Royal School of Mines, Clausthal, Harz, Geimany 640 

The Royal Saxon Academy of Mining, Freiberg, Saxony ... 641 

Halle and Anhalt Mining School, Eisleben, Saxony 642 

Stockholm Polytechnic School, Stockholm, Sweden 642 

IV.— Asia :— 

Toklo College of Engineering, Tokio, Japan 642 

V. — America :— 

University of Arizona, Tucson, Arizona, United States ... 643 

University of California, San Francisco, United States ... 644 
Colorado State School of Mines, Golden, Colorado, United 

States 646 

The University of Illinois, Urbana, Champion County, 

Illinois, United Stat^ 647 

Massachusetts Institute of Technology, Boston, United States 649 

University of Michigan, Ann Arbor, Michigan, United States 651 
The Michigan Mining School, Houghton, Michigan, United 

States 653 

The University of Minnesota, Minneapolis. United States ... 654 

University of Missouri, Rolla, Missouri, United States ... 665 

Washington University, St. Louis, Missouri, United States ... 657 

College of Montana, Deer Lodge, Montana, United States ... 658 

Columbia College, City of New York, United States 659 

The Ohio State University, Columbus, Ohio, United States ... 662 
The Case School of Applied Science, Cleveland, Ohio, United 

States 663 

University of Pennsylvania, Philadelphia, Pennsylvania, 

United States 664 

The Lehigh University, South Bethlehem, Pennsylvania, 

United States 665 

Lafayette College, Baston, Pennsylvania, United States ... 667 



Index 669 



PAGE. 

a-n 18 ^xii 366 

•^m 80 ^XIII 384 

aV.-VL 124 ^XIV 888 

'Vn. 198 ^XV 432 

'^VIII 202 "XVI 468 

^1X.-X 248 * XVn.-XX 498 

<XL 

Any Publication op a Federated Institute may be placed at the end 
OP THE Volume, i,e,, "Annual Repobt," "List op Members," etc., etc. 






List op Plates:— 


PAOB. 




18 


' XII. 


80 


^XIII. ... 


124 


^ XIV. 


198 


^xv. 


202 


^ XVI. ... 


248 


* XVII. -XX 


362 





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BYB-LAW8. 



FEDERATED INSTITUTION OP MINING ENGINEERS. 



BYB-LAWS 
PM9ed at Council Meeting held on May BSthj 1891. 



I.— Constitution. 

1. — The Federated Institution of Mining Engineers shall consist of all or any of 
the societies interested in the advancement of mining, metallurgy, engineering, and 
their allied industries, who shall from time to time join together and adhere to the 
Bye-Laws. 

2. — The Institution shall have for its objects — 

(a) The advancement and encouragement of the sciences of mining, metallurgy, 
engineering, and their allied industries. 

(b) The interchange of opinions, by the reading of communications from 
members and others, and by discussions at general meetings, upon improve- 
ments in mining, metallurgy, engineering, and their allied industries. 

(c) The publication of original communications, discussions, and other papers 

connected with the objects of the Institution. 

(d) The purchase and disposal of real and personal property for such objects. 

(e) The performance of all things connected with or leading to the purpose of 

such objects. 

3. — ^The offices of the Institution shall be in Newcastle-upon-Tyne, or such other 
place as shall be from time to time determined by resolution of the Ciouncil. 

4. — The year of the Institution shall end on July 31st in every year. 

5. — The affairs and business of the Institution shall be managed and controlled 
by the Council. 

II. — Membership. 

6.— The original adherents or founders are as follows : — 

(a) Chesterfield and Midland Counties Institution of Engineers, Chesterfield. 

(b) Midland Institute of Mining, Civil, and Mechanical Engineers, Barnsley. 

(c) North of England Institute of Mining and Mechanical Engineers, Newcastle- 

upon-Tyne. 

{d) South Staffordshire and East Worcestershire Institute of Mining Engineers, 
Birmingham. 

7. — ^Written applications from societies to enter the Institution shall be made 
to the Council, by the President of the applying society, who shall furnish any 
information that may be desired by the Council. 

8. — ^A. — If desired by the Council, any of the Federated Institutes shall revise 
their Bye-Laws, in order that their members shall consist of Ordinary Members, 
Associate Members, and Honorary Members, with Associates and Students, and 
section B following shall be a model Bye-Law to be adopted by any society when so 
desired by the Council. 

B. — ** The members shall consist of Ordinary Members, Associate Members, and 
Honorary Members, with Associates and Students :- - 



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BYE-LAWS. XI 

(a) Bach Ordinary Member shall be more than twenty-three yean of age, haye 
been regularly educated as a mining, metallurgical, or mechanical engineer, 
or in Bome other branch of engineering, according to the usual routine of 
pupilage, and have had subsequent employment for at least two years in 
some responsible situation as an engineer ; or if he has not undergone the 
usual routine of pupilage, he must have been employed or have practised as 
an engineer for at least fiye years. 

{h) Each Associate Member shall be a person connected with or interested in 
mining, metallurgy, or engineering, and not practising as a mining, metal- 
lurgical, or mechanical engineer, or some other branch of engineering. 

{c) Bach Honorary Member shall be a person who has distinguished himself by 
his literary or scientific attainments, or who may haye made important 
communications to any of the Federated Institutes. 

(d) Associates shall be persons acting as under-yiewers, under-managers, or in 
other subordinate positions in mines or metallurgical works, or employed 
in analogous positions in other branches of engineering. 

(e) Students shall be persons who are qualifying themseWes for the profession 

of mining, metallurgical, or mechanical engineering, or other branch of 
engineering, and such persons may continue Students until they attain the 
age of twenty-five years." 

9. — The Ordinary Members, Associate Members, and Honorary Members, Asso- 
ciates and Students shall have notice of, and the privilege of attending, the ordinary 
and annual general meetings, and shall receive all publications of the Institution. 
They may also have access to, and take part in, the general meetings of any of the 
Federated Institutes. 

10. — The members of any Federated Institute, whose payments to the Institu- 
tion are in arrear, shall not receive the publications and other privileges of the 
Institution. 

11. — After explanations have been asked by the President from any Federated 
Institute, whose payments are in arrear, and have not been paid within one month 
after written application by the Secretary, the Council may decide upon its suspen - 
sion or expulsion from the Institution ; but such suspension or expulsion shall only 
be decided at a meeting attended by at least two-thirds of the members of the 
Council by a majority of three-fourths of the members present. 

III.— SUBSCBIPTIONS. 

12. — Bach of the Federated Institutes shall pay fifteen shillings per annum 
for each Ordinary Member, Associate Member, Honorary Member, Associate, and 
Student, or such other sum, and in such instalment or instalments as may be 
determined from time to time by resolution or resolutions of the Council. Persons 
joining any of the Federated Institutes during the financial year of the Federated 
Institution shall be entitled to all publications issued for that year, after his 
election is notified to the Secretary, and the instalment or instalments due on his 
behalf have been paid. 

IV.— ELBCTION of OFFIGBBS AND COUNCIL. 

18. — The officers of the Institution, other than the Secretary and Treasurer, 
shall consist of Councillors elected annually prior to August in each year, by and 
out of the Ordinary Members and Associate Members of each Federated Institute, 
in the proportion of one Councillor per forty Ordinary Membei-s or Associate 
Members thereof; of Vice-Presidents elected by and from the Council at their 
first meeting in each year on behalf of each Institute, in the proportion of one 



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Xii BYB-LAWS. 

Vice-President per two hundred Ordinary Members or Associate Members thereof ; 
and of a President elected by and from the Council at their first meeting in each 
year ; who, with the Local Secretaries of each Federated Institute and the Secretary 
and Treasurer shall form the Council. All Presidents on retiring from that office 
shall be ex-officio Vice-Presidents so long as they continue Ordinary Members or 
Associate Members of any of the Federated Institutes. . 

14. — In case of the decease, expulsion, or resignation of any officer or officers, 
the Council may, if they deem it requisite, fill up the vacant office or offices at their 
next meeting. 

v.— Duties op Offigabs and Council. 

16. — The Council shall represent the Institution and shall act in its name, and 
shall make such calls upon the Federated Institutes as they may deem necessary, 
and shall transact all business and examine accounts, authorise payments and may 
invest or use the funds in such manner as they may from time to time think fit, in 
accordance with the objects and Bye-Laws of the Institution, 

16.— The Council shall decide the question of the admission of any society, and 
may decree the suspension or expulsion of any Federated Institute for non-payment 
of subscriptions. 

17. — The Council shall decide upon the publication of any communications. 

18. — There shall be three ordinary meetings of the Council in each year, on the 
same day as, but prior to, the ordinary or annual general meetings of the members. 

19. — ^A special meeting of the Council shall be called whenever the President 
may think fit, or upon a requisition to the Secretary signed by ten or more of its 
members, or by the President of any of the Federated Institutes. The business 
transacted at a special meeting of the Council shall be confined to that specified in 
the notice convening it. 

20. — The meetings of the Council shall be called by circular letter, issued to all 
the members at least seven days previously, accompanied by an agenda paper, 
stating the nature of the business to be transacted. 

21. — The order in which business shall be taken at the ordinary and annual 
general meetings may be, from time to time, decided by the Council. 

22. — ^The Council may communicate with the Government in cases of contem- 
plated or existing legislation, of a character affecting the interests of mining, 
metallurgy, engineering, or their allied industries. 

23. — The Council may appoint Committees, consisting of members of the Institu- 
tion, for the purpose of transacting any particular business, or of investigating any 
specific subject connected with the objects of the Institution. 

24. — ^A Committee shall not have power or control over the funds of the Institu- 
tion, beyond the amount voted for its use by the Council. 

25.— Committees shall report to the Council, who shall act thereon and make 
use thereof as they may elect. 

26.— The President shall take the chair at all meetings of the Institution, the 
Council, and Committees at which he may be present. 

27. — In the absence of the President, it shall be the duty of the senior Vice- 
President present to preside at the meetings of the Institution. In case of the 
absence of the President and of all the Vice-Presidents, the meeting may elect 
any member of Council, or in case of their absence any Ordinary Member or 
Associate Member to take the chair at the meeting. 



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BYB-LAWS. XIU 

28. — ^At meetings of the Council six shall be a qnornm. 

29. — Byery qnestion shall be decided at the meetings of the Conncil by the votes 
of the majority of the members present. In case of equal voting, the President, 
or other member presiding in his absence, shall have a casting vote. Upon the 
request of two members, the vote upon any question shall be by ballot. 

30. — ^The Secretary shall be appointed by and shall act under the direction 
and control of the Council. The duties and salary of the Secretary shall be fixed 
and varied from time to time at the will of the Council. 

31. — The Secretary shaU summon and attend all meetings of the Council, and 
the ordinaiy and annual general meetings of the Institution, and shall record the 
proceedings in the minute book. He shall direct the administrative and scientific 
publications of the Institution. He shall have charge of and conduct all corre- 
spondence relative to the business and proceedings of the Institution, and of all 
committees where necessary, and shall prepare and issue all circulars to the 
members. 

32. — One and the same person may hold the office of Secretary and Treasurer. 

S3. — The Treasurer shall be appointed annually by the Council at their first 
meeting in each year. The income of the Institution shall be received by him, and 
shall be paid into Messrs. Lambton & Co.*s bank at Newcastle-upon-Tyne, or such 
other bank as may be determined from time to time by the Council. 

34. — The Treasurer shall make all payments on behalf of the Institution, by 
cheques signed by two members of Council, the Treasurer, and the Secretary 
after payments have been sanctioned by Council. 

35. — The surplus funds may, after resolution of the Conncil, be invested in 
Government securities, in railway and other debenture shares such as are allowed 
for investment by trustees, in the purchase of land, or in the purchase, erection, 
alteration, or furnishing of buildings for the use of the Institution. All investments 
shall be made in the names of Trustees appointed by the CounciL 

36. — The accounts of the Treasurer and the financial statement of the Council 
shall be audited and examined by a chartered accountant, appointed by the Council 
at their first meeting in each year. The accountants* charges shall be paid out of 
the funds of the Institution. 

37. — The minutes of the Councirs proceedings shall at all times be open to the 
inspection of the Ordinary Members and Associate Members. 

YL— Gbkjebal MEBTiiras. 

38. — An ordinary general meeting shall be held in February, May, and Sep- 
tember, unless otherwise determined by the Council; and the ordinary general 
meeting in the month of September shall be the annual general meeting at which a 
report of the proceedings, and an abstract of the accounts of the previous year 
ending July 81st, shall be presented by the Council. The ordinary general meeting 
in the month of May shall be held in London, at which the President may deliver an 
address. 

39. — Invitations may be sent by the Secretary to any person whose presence at 
discussions shall be thought desirable by the Council, and persons so invited shall be 
permitted to read papers and take part in the proceedings and discussions. 

40. — Discussion may be invited on any paper published by the Institution, at 
meetings of any of the Federated Institutes, at which the writer of the paper may 
be invited to attend. Such discussion, however, shall in all cases be submitted to 
the writer of the paper before publication, and he may append a reply at the end of 
the discussion. 



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XIV BYE-LAWS. 

VII.— Publications. 
41. — ^The publications may comprise: — 

(a) Papers upon the working of mines, metallurgy, engineering, railways and 

the varions allied indnstries. 

(b) Papers on the management of industrial operations. 

(c) Abstracts of foreign papers upon similar subjecta 

(^) An abstract of the patents relating to mining and metallurgy, etc. 

(e) Notes of questions of law concerning mines, manufactures, railways, etc. 

42. — Each paper (with complete drawings, if any, to scale), to be read at any 
meeting of the Institution or of any of the Federated Institutes shall be placed in 
the hands of the Secretary at least fourteen days before the date of the meeting at 
which the paper is to be read, and shall, subject to the approral of the Gouncil, be 
printed, together with any discussion or remarks thereon. 

48. — ^The Council may accept communications from persons who are not members 
of the Institution and allow them to be read at the ordinary or annual general 
meetings. 

44. — No paper which has already been published (except as provided for in Bye- 
Law 41) shall appear in the publications of the Institution. 

45.^A paper in course of publication cannot be withdrawn by the writer. 

46. — Proofs of all papers and reports of discussions forwarded to any person for 
revision must be returned to the Secretary within seven days from the date of their 
receipt, otherwise they will be oonsideretl correct and be printed off. 

47.— The copyright of all papers accepted for printing by the Council shall become 
vested in the Institution, and such communications shall not be published for sale or 
otherwise without the written permission of the Council. 

48. — Twenty copies of each paper and the accompanying discussion shall be 
presented to the writer free of cost. He may also obtain additional copies upon 
payment of the cost to the Secretary, by an application attached to his paper. 
These copies must be unaltered copies of the paper as appearing in the publication 
of the Institution, and the cover shall state that it is an ** Excerpt from the 
Transactions of the Federated Institution of Mining Engineers." 

49. — The Federated Institutes may receive copies of their own portion of the 
publications in respect of such of their members as do not become members of the 
Federated Institution, and shall pay 10s. per annum in respect of eveiy copy so 
supplied ; and similar copies for exchanges shall be paid for at cost price. 

50. — The Local Secretary of each Federated Institute shall prepare and edit all 
papers and discussions of such Institute, and promptly forward them to the 
Secretary, who shall submit proofs to the Local Secretary before publication. 

51. — A list of the members, with their last known addresses, shall be printed in 
the publications of the Institution. 

52.— The publications of the Institution shall only be supplied to members, and 
no duplicate copies of any portion of the publications shall be issued to any member 
or Federated Institute unless by order of the Council. 

53. — ^The annual volume or volumes of the publications may be sold, in the com- 
plete form only, at such prices as may be determined from time to time by the 
Council ; to non-members for not less than £8 ; and to members who are desirous of 
completing their sets of the publications, for not less than 15s. 

54. — The Institution as a body is not responsible for the statements and opinions 
advanced in the papers which may be read or in the discussions which may take 
place at the meetings of the Institution, or of the Federated Institutes. 



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BYE-LAWS. XV 

VIII.— Medals and othbb Bewabds. 

55. — ^The Oouncil may award annoally the sam of twenty poands, in the form 
of medalB or other rewards, to the authors of papers published by the Institution. 

IX. — Pbopebtt. 

66. — The capital fund shall consist of such amounts as shall from time to time be 
determined by resolution of the Council. 

57. — ^The Institution may make use of the following receipts for its expenses : — 
(a) The interest of its accumulated capital fund ; 
(() The .annual subscriptions ; and 
(0) Beceipts of all other descriptions. 

58.— The Institution may form a collection of papers, books, and models. 
,59. — Societiea or members who may have ceased their connexion with the 
Institution shall have no claim to participate in any of its properties. 

60.— All donations to the Institution shall be acknowledged in the annual report 
of the ConnciL 

X.— Alteration of Bye-Laws. 

61. — No alteration shall be made in the Bye-Laws of the Institution, except at a 
special meeting of the Council called for that purpose, and the particulars of every 
such alteration shall be announced at their previous meeting, and inserted in the 
minutes, and shall be. sent to all members of Council at least fourteen days previous 
to such special meeting, and such special meeting shall have power to adopt any 
modification of such proposed alteration of the Bye-Laws, subject to confirmation 
by the next ensuing Council meeting. 



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XVl LIST OF XBMBER8. 



THE FEDERATED INSTITUTION OF MINING ENGINEERS. 



OFFICERS, 1892-93. 



I>rc0i^ent 

O. LEWIS, Esq., Imperial Chambers, Albert Street, Derby. 

W. AbmbtbohOi Jun., Esq., WiDgate, Co. Durham. 

W. CocHBANB, Esq., St. John^s Chambers, Grainger Street West, Newcastle- 

npon-Tyne. 
*T. W. Bmblbton, Esq., The Cedars, Methlej, Leeds (Bz-officio), Past-President. 
W. E. Gabfobth, Esq., West Riding CoUierj, Normanton. 
a. C. Obbenwbll, Esq., Elm Tree Lodge, Duffield, Derby. 
W. Heath, Esq., Sneyd House, Burslem, Stoke-apon-Trent. 
H. Lewis, Esq., Anuesley Colliery, Nottingham. 
J. A. Longdbn, Esq., Stan ton-by- Dale, Nottingham. 
J. B. SiMPSOW, Esq., Hedgefiekl House, Blaydon-upon-Tyne. 
A. SOFWITH, Esq., Cannock Chase Collieries, near Walsall. 

CounciL 

W. Aemstbong, Esq., Pelaw House, Chester-le-Street. 

E. Baikbbidoe, Esq., Nunnery Colliery Offices, Sheffield. 

Sib Lowthian Bell, Babt., Rounton Grange, Northallerton. 

T. J. Bewick, Esq., Broad Street House, Old Broad Street, London, B.C. 

M. Walton Brown, Esq., Westmorelauds, Low Fell, Gateshead-upon-Tyne. 

A. M. Chambers, Esq., Thomcliffe Collieries, near Sheffield. 

W. F. Clark, Esq., Qlenthorn, Holyhead Road, Hands worth, Birmingham. 

G. E. Coke, Esq., 15, Corporation Street, Chesterfield. 

R. Heath Cole, Esq., Endon, Stoke-upon-Trent. 

J. Daglish, Esq., Rothley Lake, Cambo, R.S.O., Northumberland. 

D. Dale, Esq., West Lodge, Darlington. 

T. Douglas, Esq., The Garth, Darlington. 

G. B. Forster, Esq., 3, Eldon Square, Newcastle-upon-Tyne. 

J. KiOHARD Haines, Esq., Adderley Green Collieries, Stoke-upon -Trent. 

W. F. Howard, Esq., 15, Cavendish Street, Chesterfield. 

J. Jackson, Esq., Stubben Edge, Chesterfield. 

H. Johnson, Esq., Trindle Road, Dudley, Worcestershire. 

H. Lawrence, Esq., Grange Iron Works, Durham. 

G. May, Esq., Hart6n Colliery Offices, near South Shields. 

Prop. J. H. Merivalb, 2, Victoria Villas, Newcastle-upon-Tyne. 

M. H. Mills, Esq., 15, Corporation Street, Chesterfield. 

J. Mitchell, Esq., Hegent Street, Bamsley. 

T. W. H. Mitchell, Esq., Mining Offices, Bamsley. 

M. W. Pabrington, Esq., Wearmouth Colliery, Sunderland. 

* Daoeaaed. 



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U8T OF U EMBERS. XVU 

O. B. Rhodes, Kbq., Aldwarke Main and Car House Collieries, Rotherham. 

F. SiLVBSTEB, Esq.) Thistlebniy, Newcastle, Staffordshire. 

Alex. Smith, Esq., Colmore Chambers, .3, Newhall Street, Birmingham. 

W. Spbkcee, Esq., Southfields, Leicester. 

A. L. Steavbnson, Esq., Durham. 

John Stbick, Esq., Bar Hill, Madeley, Staffordshire. 

Rdwabd B. Wain, Esq., Whitfield Collieries, Norton-le-Moor, Stoke-upon-Trent. 

Lindsay Wood, Esq., The Hermitage, Chester-le-Street. 

(Treadutet* 

Reginald Quthbie, Esq., Nerille Hall, Newcastle-upon-Tyne. 

Secretary* 

M. Walton Brown, Esq., Neville Hall, Newcastle-upon-Tyne. 



LIST OF MEMBERS. 



f)onorati2 Aembers. 

Federated Institution of Mining Mhngineert, 

J. B. Atkinson, Esq., H.M. Inspector of Mines, Glasgow. 

W. N. Atkinson, Esq., H.M. Inspector of Mines, Newcastle, Staffordshire. 

W. Bbattie-Scott, Esq., H.M. Inspector of Mines, Great Barr, near Birmingham. 

Thomas Bell, Esq., H.M. Inspector of Mines, Durham. 

C. Lb Neve Foster, Esq., H.M. Inspector of Mines, Llandudno. 

John Qebraed, H.M. Inspector of Mines, Worsley, near Manchester. 

Henry Hall, Esq., H.M. Inspector of Mines, Rainhill, Prescott. 

J. L. Hedley, Esq., H.M. Inspector of Mines, 22, Hawthorn Terrace, Newcastle- 
upon-Tyne. 

J. S. Mabtin, Esq., H.M. Inspector of Mines, Clifton. 

Joseph T. Robson, Esq., H.M. Inspector of Mines, Swansea. 

J. M. RoNALDSON, Esq., H.M. Inspector of Mines, 44, Athole Gardens, Glasgow. 

A. H. Stokes, Esq., H.M. Inspector of Mines, Greenhill, Derby. 

Fbank N. Wabdell, Esq., H.M. Inspector of Mines, Wath-upon-Dearne, near 
Rotherham. 

Ckegterfield arid Midland Counties Institution of Engineers, 

Prof. Frank Clowes, University College, Nottingham. 
Rev. J. M. Mello, Mapperley Vicarage, near Derby. 

Midland Institute of Mining, OivH^ and Mechanical Engineert. 

Pbof. G. F. Abmstbono, The University, Edinburgh. 
Pbof. a. H. Gbbbn, 137, Woodstock Road, Oxford. 
Pbof. L. C. Miall, Yorkshire College, Leeds. 
Pbof. Ebbinoton Ruckeb, Clapham Park, London. 
R. Russell, Esq., Sea View, St. Bees, Carnforth. 

Pbof. T. E. Thobpe, Science and Art Department, South Kensington, London, 
S.W. 

VOL. Y.-U01 ». ^ 



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ZVIU LIST OF MEMBERS. 

North of England Institute of Mining and Afeehanical Engineers, 
The Right Honourable the Earl op Ravenswobth, Ravensworth Castle, 

Gatcsheacl-upoii-Tyne. 
Prop. P. Phillips Bedson, Durham College of Science, Newcastle-upon-Tyne 
Prop. G. 8. Brady, Durham College of Science, Newca8tle-uix)n-Tyne. 
Dr. Brassert, Berghauptmann, Bonn-am- Rhein, Prussia. 
Jos. Dickinson, Esq., South Bank, Pendleton, Manchester. 
Prop. William Garnett, 13, Spring Gardens, London, S.W. 
Prof. A. S. Herschel, Observatory House, Slough, Bucks. 
The Vert Rev. Dr. Lake, Dean of Durham. 

Prop. G. A. Lebour, Durham College of Science, Xewcastle-upon-Tyne. 
J. A. LONQRIDQE, Esq., GrSve d'Ayett6, Jereey. 
Prof. H. Stroud, Durham College of Science, Newcastle-upon-Tyne. 
Ai. E. VuiLLEMiN, Mines d*Aniche, Nord, France. 

North Staffordshire Institute of Mining and Meehanioal Engineers, 

M. JuLiEK Debt. 

Hugh R. Makepeace, Esq., H.M. Inspector of Mines, Newcastle. Staffordshire. 
R. P. W. Oswald, Esq., H.M. Inspector of Mines, Hensingham, Whitehaven. 
Henrt Skipfington Poole, Esq., Acadia Coal Company, Ltd., Stellarton, 

Nova Scotia. 
A. R. Saw ITER, Esq., c/o Thompson, Watson, & Co., Cape Town, South Africa. 
C. M. Stuart, Esq., St. Dunstan's College, Lewisham. 

South Staffordshire and East Worcestershire Institute of Mining 
Engineers. 

W. J. Lancaster, Esq., Colmore Row, Birmingham. 
Prop. C. Lapworth, Ma^n College, Birmingham. 
Ralph Moore, Esq., Glasgow. 
G. H. Morley, Esq., Mason College, Birmingham. 
Prop. J. H. Poynting, Mason College, Birmingham. 
Prop. R. H. Smith, Mason College, Birmingham. 
Prop. W. A. Tylden, Mason College, Birmingham. 



Aembers. 

*DeoeaMd. 
Aburbow, Charles, Box 5, Post Office, Johannesburg, Transvaal. 
ACKROYD, A., Morley Main Collieries, Leeds. 
AcKROYD, Wm., Morley Main Collieries, Morley, near Leeds. 
Adams, Charles, Whitfield Collieries, Norton-le-Moors, Stoke-upon-Trent. 
Adams, J. 

AoNiKL, S., Mines de Vicoigne (Nord), Noeux (P. de C), France. 
Aitkin, Henry, Falkirk, N.B. 
Allan, George, Comgreaves Hall, Birmingham. 
Allan, John F., c/o Messrs. Caldwell and Watson, 109, Fenchnrch Street, 

London, E.C. 
Allan, T. A., c/o. Messrs. Gibbs, Bright, & Co., Melbourne, Australia, 
Allen, Reuben, Birch Coppice Colliery, Polesworth, near Tamworth. 
Allkn, W. S., Woodhead Hall, Cheadle, Staffordshire. 



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LIST OF MEMBERS. XIX 

Allhuskn, Alfred, Musgrave House, Gateshead-npon-Tyne. 

AI4LISON, J. J. C, Woodland Collieries, Butterknowle, R S.O., Co. Durham. 

Allsop, Samuel, Marehay Collieries, Derby. 

Almond, Edwaed Ebnest, Park Hall Colliery, Cheadle, Staffordshire. 

Alsop, a. B., Pinxton Collieries, Alfreton. 

Alsop, Samuel, Pool Close, Pinxton, Alfreton. 

Andsuson, C W. 

Andbbson, R. S., Elswick Colliery, Newcastle-upon-Tyne. 

Andrews, George Murray, Broomhill Colliery, Northumberiand. 

Andrews, Hugh, Swarland Hall, Felton, Northumberiand. 

Andrews, Thomas, Wortley Iron Works, near Sheffield. 

Angus, Jambs, Radcliffe, Acklington, Northumberland. 

Anley, Jambs P. B., Bradley Green, near Congleton. 

Archer, Joseph, Queen Insurance Buildings, Church Street, Sheffield. 

Archer, T., 6, Park Terrace, Gateshead-upon-Tyne. 

Archer, William, Victoria Garesfield, Lintz Green. 

Armson, Jesse, Coleorton Colliery, Ashby-de-la-Zouch. 

Armstrong, Lord, C.B., LL.D., D.C.L., Cragside, Rothbury. 

Armstrong, Ht., Chester-le-Street. 

Armstrong, J. H., St. Nicholas* Chambers, Newcastle-upon-Tyne. 

Armstrong, T. J., Hawthorn Terrace, Newcastle-upon-Tyne. 

Armstrong, Wm., Pelaw House, Chester-le-Street. 

Armstrong, W., Jun., Wingate, Co. Durham. 

Arnold, T., Castle Hill, Greenfields, Lianelly. 

Ashington Colliery, Owners op, Newcastle-upon-Tyne. 

Ashton, J. H., Waleswood Colliery, near Rotherham. 

ASHWIN, G. H., Charity Colliery, Bed worth, near Nuneaton. 

Ashworth, Thomas, Pratt Street, Fenton, Stoke-upon-Trent. 

Askew, EL G., Riddings, Alfreton. 

Asquith, T. W., Harperley, Lintz Green, Newcastle-upon-Tyne. 

Aston, J. , Blowers Green, Dudley, Worcestershire. 

Atkins, S. 8., Fence, Rotherham. 

Atkinson, A. A., Barrow Collieries, Bamsley, Yorkshire. 

Atkinson, C. W., The Electrical Coal Cutting Contract Corporation, Limited, 2, 

St. Nicholas' Buildings, Newcastle-upon-Tyne. 
Atkinson, Fred. R., Lawton Hall, Stoke-upon-Trent. 
Atkinson, G. B., Maritime Buildings, Quay, Newcastle-upon-Tjme. 
Atkinson, J. W., Stemdale Road, Millhouscs, Sheffield. 
Atkinson, L. B., Messrs. W. T. Goolden & Co., Woodfield Works, Harrow Road, 

London. 
. Atkinson, W. N., H.M. Inspector of Mines, Newcastle, Staffordshire. 
Aubrey, R. C, The Midland Coal, Coke, and Iron Co., Limited, Halmerend near 

Newcastle, Staffordshire. 
AUDUS, T. , Mineral Traffic Manager, North Eastern Railway, Newcastle-upou-Tyne. 
Austin, T. W., Grassmoor, Chesterfield. 
AusTiNB, John, Cadzow Coal Co., Glasgow. 

Ayton, Ernest F., El Bote Mining Negociacion, Zacatecas, Republic of Mexico. 
Ayton, Henry, 122, Rye Hill, Newcastle-upon-Tyne. 

Bailbs, E. T., Wingate, Ferryhill. 

Bailes, G. M., Coton Road, Nuneaton. 

Bailes, T., Jesmond Gardens, Newcastle-upon-Tv ne. 



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ZX LIST OF MEICBEBB. 

Bailes, William. 

Bailey, E. J., 30, Waterloo Street, Binninghani. 

Bailey, Samuel, 30, Waterloo Street, Birmingham. 

Bain, B. Doxald, H.M. Inspector of Mines, 85, Pembroke Road, Clifton, Bristol. 

Bainbridoe, Emesson, Nunnery Colliery Offices, Sheffield. 

Bakeb, Godfrey, Lowe's Hill, Ripley, Derby. 

Baker, James L. 

Bakewell, James G., Newcastle, Staffordshire. 

Ball, Alfred F., 14, Lansdowne Terrace, Gosforth. 

Ball, George, Blackwell Collieries, Alfreton. 

Ball, Josiah, Teversal Collieries, Mansfield. 

Bancroft, Robert E., 8, St James' Square, Manchester. 

Banks, Thomas, 60, King Street, Manchester. 

Barber, Thomas, Lamb Close House, Eastwood, Notts. 

Barnes, Alfred, Ashgate Lodge, Chesterfield. 

Barnes, A. G., Grassmoor Collieries, Chesterfield. 

Barnes, A. T. H., Grassmoor Collieries, Chesterfield. 

Barnes, A. W., Sutton Rock, Chesterfield. 

Barraclough, Samuel, Union Foundry, Bamsley. 

Barrass, M., Tudhoe Colliery, Speunymoor. 

Barrett, C. R., WhitehiU HaU, Chester-le-Street. 

Barrow, J. B., Ringwood Hall, Chesterfield. 

Bartholomew, C, Castle Hill House, Ealing, London, W. 

Bartholomew, C. W., Blakesley Hall, near Towcester. 

Barwell, W. H., Mill House, Treeton, Rothcrham. 

Bateman, James T., Messrs. Lever Brothers, Limited, Port Sunlight, near 
Birkenhead. 

Bates, Sidney, The Grange, Prudhoe-npon-Tyne. 

Batey, John, Newbury Collieries, Coleford, Bath. 

Batty, W., Darley Grove, Worsbro' Dale, Bamsley. 

Baumgartner, W. 0., 2, Ash Place, Newcastle Road, Monkwearmouth, Sunder- 
land. 

Baxter, Henry, Copeland Street, Stoke-upon-Trent. 

Bayldon, Daniel Hy., 3, Drapers' Gardens, London, E.C. 

Bayley, Thomas, M.P. 

Beanlands, Arthur, Palace Green, Durham. 

Bbdson, Prof. P. Phillips, Durham College of Science, Newcastle-upon-Tyne. 

Beech, Noei. Tench, Muxton House, near Newport, Salop. 

Bell, B. T. A., Secretary of General Mining Association of the Province of 
Quebec, Ottawa, Canada. 

Bell, C. E., Park House, Durham. 

Bell, J., Wardley Colliery, Newcastle-upon-Tyne. 

Bell, Sir Lowthian, Bart., D.C.L., Rounton Grange, Northallerton. 

Bell, Thos. Hugh, Middlesbrough-upon-Tees. 

Bell, Walter, 23, Windsor Terrace, Newcastle-upon-Tyne. 

Bennett, Alfred H., Dean Lane Collieries, Bedminster, Bristol. 

Bennett, A. W., Laneside, Tong Road, Famley, Leeds. 

Bennett, J., Langwith Colliery, near Mansfield. 

Bennett, J. T., Featherstone Main Colliery, Pontefract. 

Benson, J. G., 12, Grey Street, Newcastle-upon-Tyne. 

Benson, T. W., 11, Newgate Street, Newcastle-upon-Tyne. 

Benson, W. A., Silverdale, Staffordshire. 



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LIST OF MEMBEBS. Xxi 

Bentham, Josiah, Thomhill, near Wigan. 

Bknton, W. £., Midland Coal, Coke, and Iron Co., Apedale, Newcastle, 

Staffordahire. 
Bkbkley, C, Marley Hill, Swalwell, KS-O., Co. Durham. 
Bkbkuet, Fbedbbick, Lumley Thicks, Fence Houses. 
Berkley, R. W., Marley Hill, Swalwell, R.S.O., Co. Durham. 
Bebby, Thomas, Bagnall's Houses, Swalwell, R.S.O. 
Beswick, Robkbt, Chell Collieries, Tunstall, Staffordshire. 
Bewick, T. J., Broad Street House, Old Broad Street, London, E.C. 
Beynok, J. C. S., P.O. Box 1364, Johnannesburg, Transvaal 
Bigoe, D. Selby, 27, Mosley Street, Newcastle-upon-Tyne. 
BiooE, Edward Ellison, General Mining Association, Limited, Blomfield House, 

London Wall, London, E.C. 
BiGLAND, J., Henknowle, Bishop Auckland. 
BiLOBAMi, Syed Ali Shamsul Ulama, Director-General of Mines, Hyderabad, 

Deccan, India. 
BiNNS, G. J., Netherseal Colliery. Burton-upon-Trent. 
BiBAM, B., Waterloo Port, Carnarvonshire. 
BiBTLEY Ibon Company, Birtley. 

Bishop, James, Grey Valley Coal Co., Brunnerton, Greymouth, New Zealand. 
BiTZOs, N. J., c/o A. G. Sourlas, Balouk Bazaar, Constantinople. 
Black, W., Hedworth Villa, South Shields. 

Blackbubn, W. Stevenson, Aive Villas, Astley, Woodlesford, near Leeds. 
Blackett, W. C, Jun., Acorn Close, Sacriston, Durham. 
Blakbley, a. B., Soothill Wood Colliery, Batley. 
Blakemore, W., Jun., Alderidge, Walsall. 
Blenkiron, J. B., 3, Albert Terrace, Middlesburgh. 
Blood, John, HucknaU Huthwaite, near Mansfield. 
Bloor. John, Newton, near Alfreton. 

BoLAM, Philip, North Walbottle Colliery, Newcastle-upon-Tyne. 
Bolton, Edoab Ormbrod, Executor of Col. Hargieaves, Colliery Office, 

Burnley. 
Bolton, H. H., Newchurch Collieries, near Manchester. 
BoNSER, Edward, New HucknaU Colliery, Mansfield. 
BoNSOR, Harold, 30, Finsbnry Road, Leeds. 
Booth, Aaron, B Winning, Black well Colliery, Alfreton. 
Booth, J. T., Longstile, Talke, near Stoke-upon-Trent. 
Bott, Samuel, The Villas, Stoke-upon-Trent. 

Boucher, A. S., P.O. Box, 53, BLrugersdorf, South African Republic. 
BouLTON, William, Burslem, Stoke-upon-Trent. 

Bourne, John, Jun., The Manor House, HUderstone, near Stone, Staffordshire. 
BowEN, J., Broad Street, Bilston. 
Bowes, Thomas, Pontop Colliery, Lintz Green Station. 
Boyd, Wm., North House, Longbenton, Newcastle-upon-Tyne, 
Bradford, George, Witton Park, Darlington. 
Bradley, Richard, Victoria Foimdry, Wakefield. 
Brady, Prof. G. S. , Durham College of Science, Newcastle-upon-Tyne. 
Braggb, G. S., Granville Colliery, Swadlincote, Burton-upon-Trent. 
Bramley, George, Clay Cross Works, Chesterfield. 
Bramley, William, Marlpool, near Derby. 

Bbamwell, Hugh, Great Western Colliery, near Pontypridd, Glamorganshire. 
Brassert, Dr., Berghauptmann, Bonn am Rhein, Prussia. 



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XXU LIST OF MEMBERS. 

Brkakkll, Th iMAS, Brassington, near Derby. 

Brbckon, J. R., 63, John Street, Sunderland. 

Brewis, George, Boythorpe Colliery, Chesterfield. 

Bridgett, William, Bucknall, Stoke-upou-Trent. 

Bridgewater Trustees, c/o Clifford Smith, Bridgewater Offices, Walkden, 

Bolton-le-Moors, Lancashire. 
Bribrley, W., Roche Colliery, Batley. 

Broja, Richard, Koeniglicber Oberbergrath, 35, Fri^drich Strasse, Halle, a/S. 
Bromley, Oliver, Florence Colliery, Longton, Staffordshire. 
Brooke, Ed., Edgerton, near Huddersfield. 
Brouoh, Ben'nett H., 5, Robert Street, Adelphi, London, W.C. 
Brouoh, Thomas, New Seaham Colliery, Sunderland. 
Brough, William, Silverdale, Staffordshire. 
Broughall, J., Bushbury, Priestwood Road, Wolverhampton. 
Brown, E., St. John's Colliery, Norraanton. 

Brown, M. Walton, Westmorelands, Low Fell, Gateshead-upon-Tyne. 
Brown, Robert M., Norwood Colliery, via Darlington. 
Brown, R. O., Elswick Collieries, Newcastle-upon-Tyne. 
Brown, Thomas, Westport Coal Co., Millerton, Westport, New Zealand. 
Brown, Thos. Forster, Guildhall Chambers, Cardiff. 
Brown, Westoarth F., Alston House, Cardiff. 

Browne, Sir Benjamin C, Westacres, Ben well, Newcastle-upon-Tyne. 
Browne, Hugh, Aspley Cottage, Nottingham. 
Browne, R. J., Barakar East India Railway, Bengal. 
Bruce, John, Port Mulgrave, Hinder well, R.S.O., Yorkshire. 
Brunt, Ishmael, Ubberley Colliery, Bucknall, Stoke-upon-Trent. 
Brunt, James, Park Road, Fenton, Stoke-upon-Trent. 
•Bryham, William, Rosebridge Colliery, Wigan. 
Bryham, W., Jun., Douglas Bank Collieries, Wigan. 
Buckley, Frank Ernest, Liverpool Road, Kidsgrove, Staffordshire. 
BuoLASS, John, Stobswood, via Acklingbon, Northumberland. 
BuixocK, J., Pelsall, Wallsall. 
Bulman, E. H., Shincliffe Rectory, Durham. 

BuLMAN, H. F., Byer Moor, Bumopfield, near Newcastle-upon-Tyne. 
BuNKELL, H. B., P.O. Box 962, Johannesburg, Transvaal. 
BuNNiNG, C. Z., c/o The Borax Co., Limited, 2, Macri Khan, Constantinople. 
BuRDON, A, E., Hartford House, Cramlington, Northumberland. 
Burls, Herbert T , Box 76, Barberton, Transvaal, South Africa. 
Burn, F. H., West Cliff, Elmfield Road, Gosforth, Newcastle-upon-Tyne. 
Burn, Jambs, 28, Fawcett Street, Sunderland, 
Burnley, G. J., Birthwaite Hall, Darton, Barnsley. 
Burns, David, Canal Bank, Carlisle. 
Burns, J. B., The Oaklands, Rugeley. 

Burrows, J. S., Yew Tree House, Atherton, near Manchester. 
Butcher, H. T. 

Butcher, William, Chesterton, Staffordshire. 
Bute, Marquess of, Bute Estate Office, Aberdare, South Wales. 
Butterknowle Colliery Co, , Limited, Darlington. 
Buxton, German, Moira Colliery, Ashby-de-la-Zouch. 

Cadman, James C, Silverdale Collieries, Newcastle, Staffordshire. 
Calderwood, Robt., Fifeshlrc Miin Collieries, Limited, Oakley, Dunfermline. 



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LI8T OF MlilMBEBS. XXiu 

Callxar, B., 21, Chnrch Road, Gosley, Bilston. 

Candlsb, T. E. 

Gapell, Rev. G. M., Passenham Rectory, Stony Stratford. 

Gabxes, GhaUles Spearman, Hutfcon Henry Colliery, Wingate, R.S.O., Co. 

Durham. 
Gakb, Robert, Usworth Colliery, Washington, R.S.O. 
Garr, Wm. Cochran, Benwell Colliery, Newcastle-upon-Tyne. 
Carrington, Arthur, Warney Lee, Darley Dale, Matlock Bridge. 
Garrinoton, T., Kiveton Park Colliery, Sheffield. 
Garter, R., Spring Bank, Harrogate. 
Ghadwick, S. R., Eckington Collieries, Rotherham. 
Ghallinor, Charles, Basford Hall, Stoke-upon-Trent. 
Chalmers, George, Superintendent of the St. John del Rey Mining Co , 28, 

Tower Chambers, Flnsbury Pavement, London, E.C. 
Chambers, Alfred, Eastwood, Notts. 
Chambers, A. M., Thomcliffe Collieries, near Sheffield. 
Chambers, Granville, Digby Collieries, Gilt Brook, Newthorpe, Notts. 
Chambers, Henry, Tinsley Collieries, Sheffield. 
Chambers, Isaac, Watnall Colliery, Nottingham. 
Chambers, J. E., Tinsley Collieries, Sheffield. 
Chambers, J. E. F., The Hurst, Alfreton. 
Chambers, William, Brinsley Colliery, Eastwood, Notts. 
Chambers, Wm. Ht., Conisborough, Rotherham. 
Chambers, W. Hoole, Tankersley Colliery, near Bamsley. 
Chandler, N., Hednesford, Staffordshire. 
Chandley, Charles, Aberdare, South Wales. 
Chapman, A. C., 29, St. Nicholas' Buildings, Newcastle-upon-Tyne. 
Charleton, a. G., c/o G. P. Charleton, Dovercourt, Essex. 
Charlton, W., Linares, Provincia do Jaen, Spain. 
Charlton, W. A., Ravens wood, Uddington. near Glasgow. 
Charlton, William, Alpine Villas, Bloxwich Road, Walsall. 
Cheesman, E. T., Shire Moor Colliery, Newcastle-upon-Tyne. 
Chessman, Herbert, Hartlep jol. 

Cheesman, I. T., Throckley Colliery, Newcastle-upon-Tyne. 
Chessman, W. T., Hartlepool. 
Chester, P. M., Oakwell Colliery, Ilkeston. 
Chicken, Lancelot W., Boldon Colliery, Co. Durham. 
Childe, Henry S. , Wakefield. 

Chrystle, Thomas, Florence Colliery, Longton, Staffordshire. 
Clamp, Elijah, Birch Coppice Colliery, near Tamworth. 
Clare, Henry, Birchen wood Colliery Company, Limited, Kidsgrove, Scoke-upon- 

Trent. 
Clark, C. F., Garswood Goal and Iron Co., Limited, near Wigan. 
Clark, John, The Grove, Aldercar, Langley Mill, Notts. 
Clark, R. B., Springwell Colliery, Gateshead-upon-Tyne. 
Clark, Thomas, Dipton Colliery, Lintz Green Station. 
Clark, \V. F., Glenthom, Holyhead Road, Handsworth, Birmingham. 
Clarke, C. R., Stone, Staffordshire. 
Clarke, E. B., 38, Norfolk Street, Sheffield. 
Clarke, George, Estate Office, New toii-le- Willows, Lancashire. 
Clarke, James A., Ayr Colliery, Annbank, N.B. 
Clarke, T. B. A., Belground, Tankersley, Barnsley. 



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XXIV LIST OF MEMBERS. 

Claughton, G. H., The Priory, Dudley, Worcestershire. 

Clat, 8. £., Trebovir, Alexandra Road, Oipsey Hill, London, S.E. 

Clay, Zachakiah, New Watnall, Nottingham. 

Clayton, C. D., Doncaster. 

Clayton, W. W., c/o Messrs. Hndswell, Clarke, & Co., Loco. Builders, Leeds. 

Cliffe, Albert, 7, Knowsley Road, vSt. Helen's, Lancashire. 

Clough, James, Willow Bridge, Cboppington, Morpeth. 

Clowes, Prof. F , University College, Nottingham. 

CoBBOLD, C. H., Wentworth Castle, Barnsley. 

Cochrane, B., Aldin Grange, Durham. 

Cochrane, C. , Green Royde, Pedmore, near Stourbridge. 

Cochrane, Henry Heath, Eshwood Hall, Durham. 

Cochrane, Napier, Aldin Grange, Durham. 

Cochrane, R, D., Hetton Colliery Offices, Fence Houses. 

Cochrane, W., St. John's Chambers, Grainger Street West, Newcastle-upon-Tyne. 

Cochrane, William Percy, 6, Tankerville Terrace, Newcastle- upon Tyne. 

CooKiN, T. H., Tinsley Park Colliery, Sheffield. 

Cob, W. S., 22:), Birchfield Road, Birmingham. 

Coke, G. £., 15, Corporation Street, Chesterfield. 

Cole, C. E., Pensnett, Dudley, Worcestershire. 

Cole, John H., Elnypersley, Biddulph, near Congleton. 

Cole, Robert Heath, Endon, Stoke-upon-Trent. 

Collins, Arthur Launcelot, 14 and 15, Broad Street Avenue, London, E.C. 

CoLLis, W. B., Swinford House, Stourbridge, Worcestershire. 

Colquhoun, T., West Stanley Colliery, Co. Durham. 

Cook, J., Washington Iron Works, Washington, Co. Durham. 

Cooksey, J. H., West Bromwich. 

Cooper, R. W., Newcastle-upon-Tyne. 

Corbett, V. W., Chilton Moor, Fence Houses. 

CoRBiTT, M., Teams, Gateshead -upon-Tyne. 

CoRLETT, G. S., Rowbottom Square, Wigan. 

CoRNETT, J. p.. Ford Paper Works, Hylton, Sunderland. 

CoTTEREix, O. J., 16, Bank Street, Sheffield. 

CouLflON, Frank, 10, Victoria Terrace, Durham. 

Coulthard, Francis, Minas del Penoncillo, Marbella, Provincia de Malaga, Spain. 

Cowlishaw, W. G., Etruria, Stoke-upon-Trent. 

CowPEN Coal Co., Limited, F., King Street, Newcastle-upon-Tyne. 

Cox, J. H. , 10, St. George's Square, Sunderland. 

Cox, L. C. , Swannington Colliery, Ashby-de-la-Zouch. 

Cox, S. Herbert, 13, St. Helen's Place, London, E.C. 

CoxE, E. B., Drifton, Jeddo, P.O. Luzerne Co., Pennsylvania, U.S.A. 

CoxoN, M. R., Mining Offices, Barnsley. 

Cradock, G., Rope Works, Wakefield. 

Craio, Ernest, Brynkinalt Colliery, Chirk, North Wales. 

Craig, W. Y. . Milton House, Alsager, Cheshire. 

Craik, T., Church Street, Barnsley. 

Craven, Hiram, Jnn., Mechanical Engineer, Sunderland. 

Craven, John, Westgate Common, Wakefield. 

Crawshaw, C. B. , The Collieries, Dewsbury. 

Creswick, a. J., Gatefield, Sheffield. 

Creswick, W., Sharlestone Colliery, Normanton. 

Criohton, John, 20, Exchange Buildings, St. Mary's Gate, Manchester. 



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LIST OF MEMfiERS. XZV 

Cbomfton, Geokok, Stanton Hall, Nottingham. 

Cboke, E. W., Forest Hall, near Newcastle-upon-Tyne. 

Cronb, J. R., Tudhoe House, via Spennymoor. 

Cboke, S. C, Forest Hall, Newcastle-upon-Tyne. 

Cbookes, Arthur, The Mount, Eckington, Rotherham. 

Gross, John, 77, King Street, Manchester. 

Croudage, G. J., Bettisfield Golliery Go., Limited, Bagillt, North Wales. 

Groudace, John, West House, Haltwhistle. 

Groudace, Thomas, Lambton Lodge, Lambton, Newcastle, New South Wales. 

Curry, W. Thos., Thornton House, Serpentine Road, Newport, Monmouthshire. 

Daores, Thomas, 20, Princess Street, Bishop Auckland. 

Daolish, John, Rothley Lake, Gambo, R.S.O., Northumberland. 

Bakers, W. R., The Loggins, Tudhoe Golliery, via Spennymoor. 

Dale, David, West Lodge, Darlington. 

Dangar, J. H. 

Darling, Fen wick. South Durham Golliery, Darlington. 

Darlington, James, Black Park Golliery, Ruabon, North Wales. 

Davby, Henry, 3, Princes Street, Westminster, London, S.W. 

Da VIES, Lt.-Gol. Jasper G. S., Marton, Middlesbrough. 

Davibs, John, Hartley House, Goundou, Bishop Auckland. 

Davies, J Hubert, P.O. Box 455, Johannesburg, Transvaal. Transactions to c/o 

Messrs. F. A. Robinson and Go., 69, Gornhill, London, E.G. 
Davies, T. J., Balls Hill, West Bromwich. 

Davibs, Watkin, Renishaw Foundry and Engineering Works, Ghesterfield. 
Davies, W. J., Bradley, Bilston. 
Davis, Henry, All Saints Works, Derby. 
Davis, Kenneth McRae, Dudley Golliery, Northumberland. 
Davy, G. H., Eckington Goliieries, Rotherham. 
Dawbarn, a. 6., 60, Gracechurch Street, London, E.G. 
Dawson, 6. J. Grosbie, Newcastle-under-Lyme, Staffordshire. 
Day, J. H., The Laurels, Bull Bridge, Ambergate, Derby. 
Deacon, Maurice, Blackwell Goliieries, Alfreton. 
Dean, Arthur, Waterloo Road, Burslem, Stoke-upon-Trent. 
Dban, Frank, Railway Foundry, Stoke-upon-Trent. 
Dean, Samuel W., 240, Waterloo Road, Burslem, Stoke-upon-Trent. 
Dean, William, Orrell Goliieries, Wigan. 
Dearden, Jos., Victoria Golliery, Heckmondwike. 
Dkby, Julien. 

Dees, J. Gibson, Floraville, Whitehaven. 
Dees, R. R., Newcastle-upon-Tyne. 
Dennis, Henry, Ruabon, North Wales. 
Denniston, Robert B., Stuart Street, Dunedin, New Zealand. 
Devonshire, The Duke of, K.G., Ghatswortb, Baslow, Derbyshire. 
DiAMom), James, Pye Bridge, Alfreton. 
Dickenson, Gharles, Northenden, Manchester. 
Dickinson, George W., Clay Gross Collieries, Chesterfield. 
Dickinson, Joseph, South Bank, Pendleton, Manchester. 
Dickinson, R. E., Bowling Iron Co., Ld., Bradford, Yorks. 
Dixon, D. W., Lumpsey Mines, Brotton, R.S.O., Saltbum-by-tho-Sea. 
Dixon, James S., 97, Bath Street, Glasgow. 
Dixon, R., 10, Glaremont Terrace, Newcastle-upon-Tyne. 



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XXVl LIST OF MSMBEBB. 

Dixon-Bbown, a. D., 27, Mosley Street, Newcaatle-upon-Tyne. 

DoBiNSON, Lanoelot, Victoria Coal Company, Park Hills Colliery, Wakefield. 

DoDD, B., Bearpark Colliery, near Durham. 

DoDi), Ctril H., St. Helens Colliery, Bishop Auckland. 

DoDD, M., Bumcroft, Hexham. 

DoDDS, A. P., 13, Dean Street, Newcastle-upon-Tyne. 

DoNKiN, W., 17, Havelock Place, Shelton, Stoke-npon-Treut. 

Douglas, A. S., Hacknall Torkard Collieries, Nottingham. 

Douglas, C. P., Parliament Street, Conaett, Co. Durham. 

Douglas, David. 

Douglas, John, Seghill Colliery, Dudley, Northumberland. 

Douglas, M. H., Usworth Colliery, Washington, R.S.O., Co. Durham. 

Douglas, T., The Garth, Darlington. 

DowDKSWELL, H., Butterknowlc Colliery, %na Darlington. 

DoTLE, Patkick, Indian Kngineering, 19, Lall Bazar, Calcutta, India. 

Draper, W., New Seaham Colliery, Sunderland. 

Dunbar, C. . Houghton Main Colliery, Bamsley. 

Dunn, Geo., Netherton Worcestershire. 

Durham, Earl of, Lambton Offices, Fence Houses. 

Durnford, H. St. John, Whamcliffe Silkstone Colliery, Bamsley. 

DuTSON, John, Orgreave Colliery, near Sheffield. 

Dyson. W. H., Eckington Collieries, Rotherham. 

Eames, W., Netherseal Colliery, Burton -upon -Trent. 
Eardlet, Edwin, 7, Wilson Street, Derby. 
Eardlkv, J. W., The Grove, Alfreton. 

Bardlet, Samuel, Stone Villas, Mow Cop, Stokc-upon-Trent. 
Eastlake a. W., Balham, London. 
Eastwood, Edward, Railway Wagon Works, Chesterfield. 
Eastwood, G. A., Tap ton Villa, Chesterfield. 
Eaton, John, Cliff House, Clown, Chesterfield . 
Eden, C. H., c/o Messrs. Vivian and Sons, Swansea. 
Edge, J. H., Coalport Wire Rope and Chain Works, Shifnal, Salop. 
Edge, John Wilcox, Burslem, Stoke- upon-Treut. 
Edwards, F. H., Forth House, Bewick Street, Nowcastle-upon-Tyne. 
Edwards, W., Bryn End, Ruabon, North Wales. 
Elge, George, Clay ton-le- Moors, Accringtou, Lancashire. 
Elge, James, Holly House, Dosthill, Taiiiworth. 
EIley, J. J. , Snydale Collieries, near Pontef ract. 
•Elliot, Sir George, Bart., 17, Portland Place, London, W. 
Elliott, J. W., Kirkby Colliery, Kirkby-in-Ashfield, Motts. 
Elliott, William, Blackwell Collieries, Alfreton. 
Ellis, W. R., Wigan. 
Ellison, C. C, Nunnery Colliery, Sheffield. 
Elsdon, Robert, The Highlands, Burnt Ash Hill, Lee, Kent. 
Elstone, Roland, 18, Sheffield Road, Barjisley. 
Elswick Coal Company, Limited, N?wca8tle-upon-Tyne. 
Elwen, Thomas Lek, Littleburn Colliery, near Durham. 
♦Embleton, T. W., The Cedars, Methley, Leeds. 
Embleton, T. W., Jun., The Cedars, Methley, Leeds. 
Eminson, J. B., Londonderry Offices, Seaham Harbour. 
Evans, William, Cliffe Vale, Stoke-upon-Trent. 
Everard, J. B. , 6, Millstone Lane, Leicester. 



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LIST OF MEMBERS. XXVU 

Faiblet, James, Craghcad and Holmside Collieries, Chester-le-Street. 

Fairlet, W., Beau Desert, Rugeley. 

Faragher, Louis, Cape Copper Co., Ltd , O'okiep, Namaqualand, South Africa. 

Farmer, A., Seaton Carew, near West Hartlepool. 

Farn WORTH, W., Swindon, Dudley, Worcestershire. 

Faulder, Joseph, Bolton Colliery, Mealsgate, via Carlisle. 

Favell, Thomas Mtlnes, Etruria, Stoke-upon-Trent. 

Fawcett, Edward, Walker Colliery, Walker-upon-Tyne. 

Fearn, J. W., Devonshire Street, Chesterfield. 

Fenwick, Barnabas, 84, Osborne Road, Newcastle-upon-Tyne. 

Fen wick, P. J., New Hucknall Colliery, Mansfield. 

Fenwick, T. E., Mayfield, Wolsingham, near Darlington. 

Ferens, Frederick J., Silksworth Colliery, Sunderland. 

Ferguson, D., The Persian Bank Mining Rights Corporation, Limited, 6, Drapers' 

Gardens, London, E.C. 
Field, J., Hill Top, West Bromwich. 
FiNCKEN, C. W., Hoyland Silkstone Collieries, Bamsley. 
Firth, J., Hunslet New Road, Leeds. 
*FiRTH, W., Water Lane, Leeds. 
Fisher, Henry, Clifton Colliery, Nottingham. 
Fisher, T. T., Walsall. 

FisuwiCK, Robert, Binchester Colliery, Co. Durham. 
FiTTON, George, Wortley, near Leeds. 
FiTTON, W. H., 6, Bersham Road, Wrexham. 

Fleming, C. E., Messrs Black, Hawthorn, and Co., Gat^shead-upon-Tyne. 
Fletcher, George, 69, Wilson Street, Derby. 
Fletcher, Herbert, The Hollins, Bolton. 
Fletcher, John, Gill House, Ulverstone. 
Fletcher, Lancei^ot, Brigham Hall, Carlisle. 
Fletcher, W. , Brigham Hall, via Carlisle. 

FoGOiN, W., North Biddick Colliery, Washington Station, Co. Durham. 
Foooo, W., Brereton Collieries, Rugeley. 

FoGGO, Watson, Messrs. Mowle and Meacock, Egerton Iron Works, Chester. 
Ford, C. F. V. , Marehay Main Colliery, Ripley, near Derby. 
Ford, Jas. , Hotel Street, Coalville, near Leicester. 
Forrest, J. C, Holly Bank Colliery, Essington, Wolverhampton. 
Forster, G. B., 3, Eldon Square, Newcastle-upon-Tyne. 
FORSTER, G. W. 

Forster, J. R., Water Company's Office, Newcastle-upon-Tyne. 
Forster, J. T., Bumhope Colliery, near Lanchester, Co. Durham. 
Forster, T. E. , 3, Eldon Square, Newcastle-upon-Tyne. 
Foster, George, Osmondthorpe Colliery, Leeds. 
Foster, Geo., Lyme House, Rotherham. 

Foster, J. W., 24, Silksworth Terrace, New Silksworth, Sunderland. 
Foster, T. J., Coal Exchange, Scranton, Pennsylvania, U.S.A. 
Fowler, George, Basford Hall, Nottingham. 
Fowler, W. C, Beeston, Notts. 
Fox, Samson, Grove House, Harrogate. 
Francis, Matthew, Halkyn Lead-mines, Flintshire. 
Frost, William, Sneyd Colliery, Burslem, Stoke-upon-Trent. 
Fryar, J. W., Seghill Colliery, Seghill, Northumberland. 



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ZZVIU LIST OF MEMBERS. 

Fryab, Mabk, Denby Colliery, Derby. 

Fbtkb, Thomas, Knutton Forge, Knutton, Newcaatle-under-Lyine. 

GALiiOWAT, T. Lindsay, Argyll Colliery, Campbeltown, N.B. 

Gallowat, W., Cardiff. 

Gallwbt, a. Payne, Box 138, Post Office, Johannesburg, Z.A.R. 

Gabforth, W. E., West Riding Colliery, Normanton. 

Garnbtt, Prof. Wm., 13, Spring Gardens, London, S.W. 

Gasooynb, Rowland, P.O. Box 1382, Johannesburg, South Africa 

Gater, Enoch, Oak Tree Cottage, Talke, Stoke-upon-Trent. 

Gbddbb, Geobob H., 142, Princes Street, Edinburgh. 

Geb&abd, James, 11, Meek's Buildings, Wigan. 

Gbreasd, John, H M. Inspector of Mines, Worsley, Manchester. 

Gibbons, J. L., Ellowes Hall, Sedgley, Staffordshire. 

GiBBS, HuBBBT, Rookery Road, Handsworth, Birmingham. 

Gnx^HRiST, J. R., Garesfield Colliery, Lintz Green, Newcastle-upon-Tyne. 

GUiL, Thomas, TroweU Moor Colliery, near Nottingham. 

GnxETT, L. F., 163, Osmaston Road, Derby. 

GiLLorr, J. W., Summer Lane, Barnsley. 

GiLROY, G., Mayfield, Orrel, Wigan. 

GiLROY, S. B., 3, Abercrombie Street, Chesterfield. 

Gjebs, John, 3, Southfield Villas, Middlesbrough. 

Glennie, W. U., 10, Oxford Road, Erdington, Birmingham. 

GrOODALL, E. M. , £^kington Collieries, Rotherham. 

Goodwin, G. A., Roodeport, Witwatersrandt, South Africa. 

Goodwin, William H., Park Hall Collieries, Longton, Staffordshire. 

GooLDEN, Walter T., 28, Westbourue Park, London, W. 

GowEB, G. G. Levbson, M.P., 14, South Audley Street, London. 

Grainoeb, James, Wollaton, Nottingham. 

Gbatton, R. T., Knifesmith Gate, Chesterfield. 

Gbaves, H. G., 5, Robert Street, Adelphi, London, W.C. 

Gbayston, F. a.. White Lodge, Glascote, Tamworth. 

Gbazebbook, a. W., Queen's Cross, Dudley, Worcestershire. 

Gbeatbach, Geokoe H., Great Fenton Collieries, Stoke-upon-Trent. 

Gbeavks, J. O. , St. John's, Wakefield. 

Green, A. T. , Aldwarke Main Colliery, Rotherham. 

Green, J. T., Ty Celyn, Abercame, Newport, Monmouthshire. 

Gbeeneb, Henry, South Pontop Colliery, Annfield Plain. 

Gbkeneb, T. Y., West Lodge, Crook, Darlington. 

Gbeknsmith, Johnson, Newstead Colliery, Nottingham. 

Green WELL, G. C, Elm Tree Lodge, Dufficld, Derby. 

Gbeenweu^, G. C, Juu.. Poynton, near Stockport. 

Gbeenwood, Prof. W. H., 21, Portland Road, Edgbaston, Birmingham. 

Gbegory, Aubrey, Dhadka Colliery, Asansol, E.I.R., India. 

Gregory, H. E., Cartonwood Colliery, Barnsley. 

Gregory, John, Sneyd Colliery, Burslem, Stoke-upon-Trent. 

Gresley, W. S., Erie, Pennsylvania, U.S.A. 

Grey, C. G., 20, Northbrook Koad, Leeson Park, Dublin. 

Gbifkith, Ed., Brjmibo Colliery, Wrexham, North Wales. 

Griffith, N. R., Plasnewydd, Ruabon, North Wales. 

Griffiths, F., Pensnett, Dudley, Worcestershire. 

Grimshaw, E. J., 23, Hardshaw Street, St. Helen's, Lancashire. 



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LIST OF MSHBSaS. XXIZ 

Gbindlet, W. H., Newfield Works, Tanstall, Staffordshire. 
Guthrie, James K., Eltringham Colliery, Prudhoe, R.S.O. 
Guthrie, Reginald, Neville Hall, Newcastle-upon-Tyne. 

Habkrshon, M. H., Thomcliffe Colliery, near Sheffield. 
Haddock, W. T., Jun. 

Hadfield, R. a., Hecla Steel Foundry, Sheffield. 
Haooie, D. H., Wearmouth Patent Rope Works, Sunderland. 
Haooie, F. W., Gateshead-upon-Tyne. 
Haooie, G. A., Wearmouth Ropery, Sunderland. 
Haooie, Peter Sinclair, Gateshead-upon-Tyne. 
Hague, Ernest, Castle Dyke, Sheffield. 

Haines, J. Richard, Adderley Green Collieries, Stoke-npon-Trent. 
Halder, Albert H., Pietersburg, Transvaal 
Hall, Edgar, Whamcliffe Silkstone Colliery, Bamsley. 
Hall, Fred. W., Haswell Lodge, Sunderland. 

Hall, George, The Bengal Iron and Steel Company, Barrakar, Bengal, India. 
Hall, John, Sheepbridge Works, Chesterfield. 
Hall, J. C, Pegswood Colliery, near Morpeth. 
Hall, L. J., Fumess Vale, Stockport. 
Hall, M., Lofthouse Colliery, Wakefield. 
Hall, M. S., 8, Victoria Street, Bishop Auckland. 
Hall, R. O. Db K., Treeton, Rotherham. 
Hall, Tom, Ryhope Colliery, via Sunderland 
Hall, W. F., Haswell Colliery, Haswell, via Sunderland. 
Hallas, G. H., Wigan and Whiston Coal Co., Limited, Prescot. 
Hai^k, Edward, 15, Clarendon Road, Notting Hill, London, W. 
Hamilton, E., Rig Wood, Saltbum-by-the-Sea. 

Hamilton, G., c/o Messrs. B. S. Lloyd and Co., 78, Queen Victoria Street, Lon- 
don, KC. 
Hamilton, J. P., Loscoe Brook, Codnor, Derby. 
Hancock, Thomas, Bagnall House, Nottingham. 

Hancock, William, 51, Alexander Road, Normacot, Longton, Staffordshire. 
Hann, Edmund, Aberaman, Aberdare. 
Hardwtck, Francis W., Firth College, Sheffield. 
Hardwick, Frederick, Eckington Collieries, Rotherham. 
Hare, Samuel, Bedlington Collieries, Bedlington, R.S.O., Northumberland. 
Hargrkaves, J., Roth well Haigh Colliery, Leeds. 
Hargreaves, Walter, Robin Hood Collieries, Wakefield. 
Hargreaves, William, Rothwell Haigh Colliery, Leeds. 
Harker, Wm., 17a, Great George Street, Westminster, London, S. W. 
Harle, Peter, Pagebank Colliery, Co. Durham. 
Harle, Richard, Browney Colliery, Durham. 
Harle, William, Pagebank Colliery, near Durham. 
Harp, Ralph, Bucknall, Stoke-upon-Trent. 
Harper, H., 63, Pitt Street, Sydney, New South Wales. 
Harper, J. P., All Saints' Chambers, Derby. 
Harris, W. S., Kibblesworth, Gateshead-upon-Tyne. 
Harrison, George, High Park Colliery, Greasley, Nottingham. 
Harrison, G. B., West Hunwick Colliery, Hun wick, R.S.O., Co. Durham 
Harrison, G. D., Waterworks, Hanley, Staffordshire. 
Harrison, W. B., Brownhills Collieries, near Walsall. 



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XXZ LIST OP MSXBEBS. 

Harbup, J. A., Westminster Collieries, Wrexham. 
Hassam, A&thur, Oldfield CoUieiy, Fenton, Stoke-upon-Treiit. 
Hassam, Wilmot J., Lane End Works, Fenton, Stoke-upon-Trent. 
Haswkix Coal Ck>., Haswell Colliery, Haswell, via Sunderland. 
Hawkes, J., Heathfield Road, Handsworth, Birmingham. 
Hay, J., Jun., Widdrington Colliery, Acklington. 
Hay, T. Y., Whitwick Colliery, Coalville, Leicester. 
Hay, William, Koetell Colliery, Wakefield. 
Hay, W., Jan., Wood View House, Stanton, Burton-npon-Trent. 
Haynks, Frank, Birley Collieries, Sheffield. 
Haywabd, W. J., West Bromwich. 
Head, Jeremiah, Queen's Square, Middlesbrough. 
Heath, A. S., Adderley Green Collieries, Stoke-upon-Trent. 
HeatA, Jambs, Clayton Hall, Newcastle, Staffordshire. 
Heath, John, Sneyd Colliery, Burslem, Stoke-upon-Trent. 
Heath, Robert, Biddulph Valley Iron Works, Stoke-upon-Trent. 
Heath, Robert, Jun., Biddulph Valley Iron Works, Stoke-upon-Trent. 
Heath, Wilj^iam, Sneyd House, Burslem, Stoke-upon-Trent. 
Heathcote, C. H., Newstead Colliery, Nottingham. 
Hedley, Chas., Black Park Colliery, Chirk, Ruabon. 
Hedley, E., Rainham Lodge, The Avenue, Beckenham, Kent. 
Hedley, J. Hunt, John Street, Sunderland. 
*Hedley, J. J., Derwent Cote House, Lintz Green Station. 
Hedley, Sept. H., Bank Chambers, Wakefield. 
Hedley, W. H., Medomsley, R.S.O., Newcastle-upon-Tyne. 
Henderson, C. W. C, The Riding. Hexham. 
Henderson, H., Pelton Colliery, Cheater-le-Street. 
Henderson, J. J., Khewra, Sind Sagar S. Railway, Punjab, India. 
Henderson, J. J., U.S. Engineer's Office, Kingsbridge, New York, U.S. A. 
Hendy, J. C. B., Colliery Office, Etherley, by Darlington. 
Henshaw, a. Mayon, Talk-o'-th'-Hill Colliery, Stoke-upon-Trent. 
Henzell, Robert, Close, Newcastle-upon-Tyne. 
Hepburn, T., Langley Park, Durham. 
Heppell, T., Leafield House, Birtley, Chester-le-Street. 
Hepplewhite, W. H., H.M. Inspector of Mines, Roscius House, Corporation 

Oaks, Nottingham. 
Herschel, Prof. A. S., Observatory House, Slough, Bucks. 
Heslinoton, Alfred, New Tupton, Chesterfield. 

Heslop, C, Upleatham and Lingdale Mines, Upleatham, R.S.O., Yorkshire. 
Heslop, Grainger, Deptford Hall, Sunderland. 
Heslop, James, The Elms, Arnold, Nottingham. 
Heslop, Thomas, Storey Lodge Colliery, Cockfield, via Darlington. 
Hetton Coal Company, Fence Houses. 
Hewitt, C. R., London Road, Derby. 
Hewitt, George, Castle Gresley, Burton-upon-Trent 
Hewitt, G. C. , Coal Pit Heath Colliery, near Bristol. 
Hewitt, H. R., H.M. Inspector of Mines, 47, Hartington Street, Derby. 
Hewitt, John Bichardson, Derby. 
Hewitt, Joseph, Heron Cross, Fenton, Stoke-upon-Trent. 
Hewitt, T. P., Swadlincote and Cadley Hill Collieries, Burton-upon-Trent. 
Hewlett, A., Haseley Manor, Warwick. 



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LIST OF MEMBERS. XXXI 

Hickman, B., Stone Quarries, Bilston. 
Hicks, Prof. W. M., Firth College, Sheffield. 

HiGOiNS, Samuel, Weston Coyney Road, near Longton, Staffordshire. 
HiosoN, Jacob, Crown Buildings, 18, Booth Street, Manchester. 
HiGSON, John, Crown Buildings, 18, Booth Street, Manchester. 
Hill, Thomas, Codnor Park, Alfreton. 

Hill, William, Carterthome Colliery Offices, Witton-le-Wear. 
Hill, William, Manor Street Foundry, Fenton, Stoke-upon-Trent. 
Hilton, J., 67, Hawkshead Street, Southport. 
Hilton, T. W., Wigan Coal and Iron Co., Limited Wigan. 
HiNGHLiFFK, J., Bullhouse Colliery, Penistone, near Sheffield. 
HntST, G. F., Aldwarke Main Colliery, Rotherham. 

HoBBS, William L., Whitfield Collieries, Norton-in-the-Moors, Stoke-npou-Trent. 
Hodges, Isaac, Sheepbridge Works, Chesterfield. 
HoDGKiNSON, Albert, The Laurels, Wollaton, Nottingham. 
Hodgson, E., Black Boy Colliery, Bishop Auckland. 
Hodgson, J., Edmondsley Colliery, Chester-le-Strcet. 
HoDSON, James, Brintirion, Prestatyn, North Wales. 
HoDSON, James £., Belgrave Terrace, Normacot, Longton, Staffordshire. 
HoLB&ooK, John, Langley Colliery, Marlpool, Derby. 
Holding, William, Cossall Colliery, Nottingham. 
HoLDSWORTH, Thomas, Clay Cross, Chesterfield. 
Holford, W. D., Whittington, Chesterfield. 
HoLLiDAY, Martin F., Langley Grove, Durham. 
HuLLiDAT, RosLYN, Fcatherstone Manor Colliery, Pontefract. 
HoLLiDAT, T., West Ardsley Collieries, Tingley, near Wakefield. 
HoLLiNS, G., High Street, Wolstanton, Stoke-upon-Trent. 
HoLLis, Henry Wm., Whitworth House, Spennymoor. 
Holmes, C, Grange Hill, near Bishop Auckland. 
*HoMER, Charles J., Stoke-upon-Trent. 
HoMSR, J. Edward, Ivy House, Hanley, Stoke-upon-Trent. 
Hood, A., 6, Bute Crescent, Cardiff. 

Hooper, £d. , c/o J. H. Hooper, College Precincts, Worcester. 
Hopkins, Edward, 13, Harrington Gardens, London, S.W. 
HoPKiNSON, Henry, Station Street, Nottingham. 
Hopkinson, John, Inglewood, St. Margaret's Road, Bowden, Cheshire. 
Hopper, J. L, Tyne Dock, South Shields. 
HosKOLD, H. D., Inspector-General of Mines of the Argentine Republic, and 

Director of the National Department of Minos and Geology, Casilla Correos, 

900, Buenos Ayres. 
HoiTFTON, Charles, Heathfield Villas, Garforth, Leeds. 
HouFTON, J. P., Bolsover Colliery, Chesterfield. 
Huulgatb, J. Kerr, 69, Lowther Street, Whitehaven. 
Howard, W. F., 15, Cavendish Street, Chesterfield. 
HowDEN, Thomas, Wakefield. 
Howe, Wm., CUy Cross, Chesterfield. 
Howes, Frank T., Singareni Collieries, Hyderabad Deccan Co., Secunderabad, 

India. 
Howl, E., The Quarries Dudley, Worcestershire. 
HuBBERSTY, H. A., Burbage, Buxton. 
Hughes, H. W,, Priory Farm House, Dudley, Worcestershire. 



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XXXll LIST OF MEMBEBS. 

Hughes, Jambs, Midland Coal and Iron Co., Minnie Pit, Halmorend, Newcastle, 

Staffordshire. 
Hughes, J., Dudley, Worcestershire. 
Hughes, Thomas George, Blackwell, Alfreton. 
Hughes, Wiluam, Springwood, Chesterton, Staffordshire. 
HuLSE, W. W., Longton Gas Works, Longton, Staffordshire. 
Humble, Joseph, Markham Collieries, Duckmanton, Chesterfield. 
Humphbeys-Davies, G., 8, Laurence Pountney Hill, Cannon Street, London, E.C. 
HuNTEK, Chbistofheb, FroomhiU Colliery, Acklington, Northumberland. 
Hurst, George, 58, Eldon Street, Newcastle-upon-Tyne. 
HuTTON Henry Coal Company, Limited, 7, Bondgato, Darlington. 
Hyslop, G. p., Mossfield Colliery, Longton, Staffordshire. 

Irvine, Joseph B., Hendon Ropery, Sunderland. 

Jackson, Alfred, Park Hall Collieries, near Longton, Staffordshire. 

Jackson, Andrew, Collins Green Collieries, Newton-le- Willows, Lancashire. 

Jackson, John, Stubben Edge, Chesterfield. 

Jackson, W. B. M., Clay Cross Hall, Chesterfield. 

Jackson, W. G., Hicklam House, Aberford, near Leeds. 

Jarratt, J., Houghton Main Colliery, Bamsley. 

Jeffoock, C. E., Birley Collieries, Sheffield. 

Jeffcock, T. W., 18, Bank Street, Sheffield. 

Jenkins, W., Ocean Collieries, Treorky, Glamorganshire. 

Jenkins, Wm., Consett Iron Works, Consett, Durham. 

Jepson, H., 20, The Avenue, Durham. 

Jepson, W. W., Portland Colliery, Selston, Alfreton. 

Jeudwine, W. W., Walton Lodge, Chesterfield. 

Jobling, T. E., Croft Villa, Blyth, Northumberland. 

Johnson, J., Carlton Main Colliery, Bamsley. 

Johnson, M. G., Talk-o'-th'-HUl Colliery, Talke, Stoke-upon-Trent. 

Johnson, W., Abram Colliery, Wigan. 

Johnson, Wm., Framwellgate Moor, Durham. 

Johnson, Wm., Radcliffe Colliery, Acklington, Northumberland. 

JoiCEY, J. G., Forth Banks West Factory, Newcastle-upon-Tyne. 

JoiOEY, James John, Sunningdale Park, Berks. 

JoiOEY, W. J. , Sunningdale Park, Berks. 

Jones, D. L,, Shelton Steel Co., Stoke-upon-Trent. 

Jones, F. J., Bother Vale Collieries, Treeton, Rotherham 

Jones, George, The Hall, Bloxwich. 

Jones, Joh.v, Shire Oaks Colliery, Worksop. 

Jones, J. A , Gijon, Asturias, Spain. 

Jones, Jacob Carlos, Bellambi, New South Wales. 

Jones, Lloyd, Ruabon, North Wales. 

Jones, K Enos, Whitwell Colliery, Whitwell, Chesterfield. 

Jones, Thomas E., Shelton Bar Ironworks, Stoke-upon-Trent. 

EIayll, a. C, Gosforth, Newcastle-upon-Tyne. 

Keep, R. S., Messrs. Horsley and Co., Tipton, Staffordshire. 

Kell, G. j., Park Road, Bamsley. 

Kellet, M. H., 6, Elm Street, South Moor, Chester-le-Stroet. 

Kbllett, William, Portland Bank, Southport. 



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LIST OF XEMBEBS. XXXiu 

Kendall, J. D., Fozhouaes Road, Whitehaven. 

Kbnrick, John P., 8, St. James' Square, Manchester. 

Kent, Geobge C, Longton, Staffordshire. 

Kestbyen, Frank, Monckton Main Colliery, Bamsley. 

KiDSON, E , Lester Street, Bilston. 

Kino, Feed., Cramlington Colliery, R.S.O., Northumberland. 

KiRKBT, J. W., Kirkland, Leven, Fife. 

KiEKUP, Austin, Murton Colliery, Sunderland. 

KntKUP, Fred. 0., Button Henry Colliery, Wingate, R.S.O., Co. Durham. 

KiRKUP, J. P., 5, Albert Edward Terrace, Whitley. 

KiRKUP, Philip, Cornsay Colliery Office, Esh, near Durham. 

KiRTON, Hugh, Kimblesworth Colliery, Chester-le-Street. 

Knighton, Herbert, High Park Colliery, Greasley, Notts. 

Knighton, H. A., Bagworth, Leiooster. 

Knowlbs, John, Weetwood, Pendlebury, Manchester. 

Knowlbs, Robert, Ednaston Lodge, near Derby. 

Lake, The Very Rev. Dr., Dean of Durham. 

Lake, Georoe, PenkhuU, Stoke-upon-Trent. 

Lamb, George, Butterley Park Collieries, Alfreton. 

Lamb, R., Troughton House, Qeator Moor, via Camforth. 

Lamb, Richard W., 29, Great Cumberland Place, London, W. 

Lancaster, John, Anfield House, Leamington. 

Lancaster, John, Heathfield, Lesmahagow, N.B. 

LANDAiiE, A., Comely Park Place, Dunfermline. 

Laporte, H., 57) Rue de la Concorde, Brussels. 

Lapworth, Prof. C, Mason College, Birmingham. 

Larmouth, William, Hareoastle and Woodshutts Colliery, Stoke-upon-Trent. 

Layerick, J. H. W., Riddings Colliery, near Alfreton. 

Laveriok, Jas., East Gawber Colliery, Bamsley. 

Layerick, John Wales, Tow Law Colliery Office, Tow Law, R.S.O., Co. 

Durham. 
Layerick, Robt., West Rainton, Fence Houses. 
Lawlet, J., Cradley Heath, Staffordshire. 
Lawrence, H., Grange Lron Works, Durham. 

Lawrence, H. L., 3, Maxilla Gardens, North Kensington, London, W. 
Laws, W. G., Town Hall, Newcastle-upon-Tyi^®* 
Lawton, G. E., Shelton Collieries, Hanley, Staffordshire. 
Lawton, T. a., Brynkinalt Collieries, Chirk, North Wales. 
Lawton, Wm., 98, Kirkmanshulme Lane, Longsight, Manchester. 
Lea, H., 38, Bennett's HUl, Birmingham. 
Leach, C. C, Seghill Colliery, Northumberland. 
Lebour, G. a., Durham College of Science, Newcastle-upon-Tyne. 
Lee, John, Whitfield Collieries, Norton-le-Moors, Stoke-upon-Trent. 
Lee, John F., Sheepbridge Iron Works, Chesterfield. 
Lees, T. G.. Clifton Colliery, Nottingham. 
Lewis, George, Imperial Chambers, Albert Street, Derby. 
Lewis, Henrt, Annesley Colliery, Nottingham. 
Lewis, Sir Whjjam Thomas, Mardy, Aberdare. 
LiDDELL, J. M., 3, Victoria Villas, Newcastle-upon-Tyne. 
LiNDAY, Jambs, Bishop Auckland. 
LiNDLEY, Edward, Eastwood, Nottingham. 

YOL. Y.-ISMM. C 



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XXZIY LIST OF MEMBERS. 

LiNDOP, J., lime Tree House. Bloxwich, WalsalL 

LiNSLET, R., Crarolington Colliery, Northaroberland. 

LiNSLET, S. W., Whitburn Colliery, Soath Shields. 

LisuMAN, R. R., Durham Main Colliery, Durham. 

LiSHMAN, T., Hetton Colliery, Hetton-le-Hole, R.S.O. 

LiSHMAN, Wm., Bunker Hill, Fence Houses. 

LiSHMAN, Wm., Holly House, Witton-le-Wear. 

LiSTJS, J., The Ottos Kopje Diamond Mines, Limited, Ottos Kopje Chambers 

P.O. Box 381, Kimberley, South Africa. 
LiYKiNO, E. H., 52, Queen Anne Street, Cavendish Square, London, W. 
LiYKitfKDOB, W. 6., Norfolk Road, Sheffield. 
LiVBSBT, C, Bradford Colliery, near Manchester. 
LiYXSKT, T., Bradford Colliery, near Manchester. 
Llbwellin, David Moboan, Glanwem Offices, PontypooL 
LLSWKLTtr, F. W., Shelton Bar Iron and Steel Works, Stoke-upon-Trent. 
LooKBTT, James, Holly Villas, Kidsgrove, Stoke-upon-Trent. 
LooKETT, William, 25, North Road, Longsight, Manchester. 
LooAN, William, Langley Park Colliery, Durham. 
Londonderry, Marquess of, c/o V. W. Corbett, Londonderry Offices, Seaham 

Harbour. 
LoNOBOTHAM, J., Barrow Collieries, Bamsley, Yorkshire. 
Longbotham, R. H., 15, Westgate, Wakefield. 
LoNODEN, J. A., Stanton-by-Dale, Nottingham. 
LoNORiDOE, J., Coxlodge Colliery, Newcastle-upon-Tyne. 
LuNORiDOE, J. A., GrSve d'Ayett^, Jersey. 

LoNOSDALB, Nigel, Harecastle and Woodshutts Colliery, Stoke-upon-Trent. 
Louis, D. A., 77, Shirland Gardens, London, W. 
LovBKiN, Emanuel, Tunstall, Staffordshire. 
LowDEN, T., Hamsteels, near Durham. 
LowRANCE, T. B., Pitt Street, Barnsley. 

LuoAS, Robert, Biddulph Valley Iron Works, Stoke-upon-Trent. 
Lucas, Samuel, Dronfield Foundry, Dronfield, Sheffield. 
LuPTON, Prof. A., 6, De Grey Road, Leeds. 
Lt!VAM, H. M., Shelton Collieries, Stoke-upon-Trent. 
Lyon, J., Walsall Wood, WalsalL 
Lton, J. W., The Firs, Annesley, Nottingham. 

Maoalpinb, G. W., Altham and Great flarwood Collieries, near Aocrington. 

MacArthur, J. S., 12, Knowe Terrace, Pollokshields, Glasgow. 

MacCabe, H. O., Russell Vale, Wollongong, New South Wales. 

McCarthy, E. T., c/o. Colonel Pigott, Archer Lodge, Charles Road, St. 

Leonards-on-Sea. 
McCreath, J., 208, St. Vincent Street, Glasgow. 
McCuLLOCH, David, Beech Grove, Kilmarnock, N.B. 
MoGowAN, John, Harecastle and Woodshutts Collieries, Stoke-upon-Trent. 
MoGowAN, John, Jun., Harecastle and Woodshutts Collieries, Stoke-upon-Trent. 
Macintosh, T., Waterloo, Bljrth. 
Mackinlay, E., East Stanley Colliery, Co. Durham. 
McLaren, B., Heddon Coal and Fire Brick Co., Wylam-upon-Tyne. 
McMurtrie, G. E. J., Foxes Bridge Colliery, Cinderford, Gloucestershire. 
McMurtrie, J., Radstock Colliery, Bath. 
Maddison, Thos. R., Dirtcar House, near Wakefield. 



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LIST OF KBMBERS. ZZZV 

Maddison, W. H. F., The Lindens, Darlington. 

Makspeacs, H. R., H.M. Lispector of Mines, NewoMtle, Staffordshire. 
Makefeacb, R. R., Newcastle, Staffordshire. 
Mauko, G. T., Ellison Place, Newcastle-upon-Tyne. 
Mamuatt, J. E., St. Andrew's Chambers, Leeds. 
Mann, Enoch, Blakeley House, Dilhome, Stoke-upon-Trent. 
Markham, C. P., Broad Oaks Iron Works, Chesterfield. 
Markham, 6. E., Coundon, Bishop Auckland. 
Makley, J. W., Thomfield, Darlington. 
Makbiott, Joseph, Jun., Acres, Pilsley, Chesterfield. 
*Mabsh, F. S., Freasley, near Tamworth. 
Mabsh, T. G., 2, Priory Street, Dudley, Worcestershire. 
Marshall, J. L., Monk Bretton Colliery, Bamsley. 
Marshall, W., Liversedge Colliery, Liversedge, via Normanton. 
Marshall, W. B., Richmond Hill, Edgbaston, Birmingham. 
Marten, £. B., Pedmore, near Stourbridge. 
Martin, C. W., Murton Colliery, via Sunderland. 
Martin, Gilson, Edensor, Chesterfield. 
Martin, R. F., Mountsorrel, Loughborough. 
Martin, Tom Pattinson, Allhallows Colliery, Mealsgate, Carlisle. 
Mascall, W. H , c/o Mrs. Race, South Church, near Bishop Auckland. 
Mason, Benj., Bnmopfield, R.S.O., Durham. 
Mathibson, Alexander, Hetton Colliery, Carrington, near Newcastle, New 

South Wale p. 
Matthews, J., Messrs. R. and W. Hawthorn, Newcastle-upon-Tyne. 
Matthews, R. F., Harehope Hall, Alnwick. 
Mauohan, J. A., Government Central Provinces Collieries, Umaria, via Katni, 

India, C.P. 
Mawson, R. Bryham, Brick House, Westleigh, Manchester. 
May, G. , Harton Colliery Offices, near South Shields. 
May, T. H., Dronfield, Sheffield. 
Maydsw, Benj., Lyme House, Whiston, Prescott. 
Mayes, G. R., Dukinfield Collieries, Dukinfield, near Manchester. 
Meachsm, F. G., Hillside Cottage, Hamstead HiU, Handsworth, Birmingham. 
Meaghem, Isaac, Jun., Batmans Hill House, Bradley, Bilston. 
MsiN, Jambs, South Normanton Colliery, Alfreton. 
Mbllino, Wm., South Leicestershire Colliery, Coalville, Leicestershire. 
Mello, Rev. J. M., Mapperley Vicarage, near Derby. 
Mellor, Herbert W., 5, Tithebam Street, Liverpool 
Mellors, James, H.M. Inspector of Mines, Outwood, Wakefield. 
Melly, E. F., Griff Colliery, Nuneaton. 

Merivals, Prof. J. H., 2, Victoria Villas, Newcastle-upon-Tyne. 
Mertvale, W., The Deanery, Ely. 
Meyer, G. A., Shamrock Collieries, Westphalia. 
Mbysey-Thomfson, a. H., Sun Foundry, Leeds. 
Middleton, Francis Ed., Lofthouse, Wakefield. 
MiDDLETON, Robert, Sheep Scar Foundry, Leeds. 

Miles, Wm. Hy., 23, Bamato Buildings, Johnannesbnrg, Transvaal, South Africa. 
Miller, N. 

MiLLEBSHiP, J. H., Watnall Colliery, Watnall, Notts. 
MiuJNOTON, Wm. Wyatt, Herdman's House, Holliugwood, Lancashire. 



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XIXVl LIST OP MEMBERS. 

Miuj9, M. H., 15, Corporation Street, Chesterfield. 

MiLUB, William A., Jasmine Villa, Newcastle, Staffordshire. 

MiLNX, Prof. John, University of Tokio, Japan. 

MiNTO, Gborok W., Chapel Row, Ouston, Chester-le-Street. 

Mitchell, Chas., Jesmond, Newcastle-upon-Tyne. 

Mitchell, Clayton E. J., West Highlands, Winchester. 

Mitchell, John, Swaithe Hall, Bamsley. 

Mitchell, Joseph, Regent Street, Bamsley. 

Mitcheij:^ T. W. H., Mining Offices, Bamsley. 

MrroHESON, G. A., Market Place, Longton, Staffordshire. 

MiTCHESON, Habbt, Dresden, Longton, Staffordshire. 

Mitohinson, R., Pontop Colliery, Lintz Green Station, Co. Dnrham. 

MiTTON, A. Dtheit, Marlpool House, near Derby. 

MoLLEB, W. A., o/o Chrys. Moller, Sioux City, Iowa, U.a A. 

MoNKHOUBS, Jos., QUorox, Carlisle. 

MooRB, R. T., 156, St. Vinoent Street, Glasgow. 

MooBB, R. W., Somerset House, Whitehaven. 

MooRB, WiUJAM, Loftns Mines, Loftus-in-Cleveland, R.S.O. 

MoBDf, W., Shelton Iron, Steel, and Coal Co., Ltd., Stoke-upon-Trent. 

Mobbing, C. A., Broad Street House, Old Broad Street, London, E.C. 

MoBOAN, C. R., Hurst Lodge, Alfreton. 

MoBOAN, Thomas, Birch Coppice Colliery, near Tamworth. 

MoBisoN, John, New battle Collieries, Dalkeith, N.B. 

MoBBis, W., Waldridge Colliery, Chester-le-Street. 

MoBTON, H. J., 2, Weetboume Villas, South Cliff, Scarborough. 

MosBT, George, Eckington Collieries, Rotherham. 

Moss, Henbt, 223« Derby Road, Nottingham. 

Mould, Enoch, White Bam Colliery, Newcastle, Staffordshire. 

MouLTON, Levi, Chesterton, Stoko-upon-Trent. 

Mountain, William C, Forth Banks, Newcastle-upon-Tyne. 

Muibhead, James, Grove Road, Fenton, Stoke-upon-Trent. 

MuLHOLLAND, M. L., West Comforth, R.S.O., Co. Durham. 

MuNDLE, Abthub, St. Nicholas* Chambers, Newcastle-upon-Tyne. 

MuNBO, Donald, Fairfield, Manchester. 

MuNBOE, Prof. H. S., School of Mines, Columbia College, New York City, U.S.A. 

Mubton, Chas. J., Delaval Benwell Colliery, Newcastle-upon-Tyne. 

MuscHAMP, Pebcival, Warren Grove, Sheffield Road, Bamsley. 

MusGBAVE, Henbt, Havercroft Main Colliery, Roystone, near Bamsley. 

Myatt, Jacob, Newcapel, Tunstall, Staffordshire. 

Nash, H. B., Clarke's Old Silkstone Colliery, Bamsley. 

Nasse, Rudolph, Geheimerbergrat, Domsbergstrasse, 6, Berlin, W., Germany. 

Natlob, John, Cotes Park Colliery, near Alfreton. 

Nevin, John, littlemoor House, Mirfield. 

Newbould, T., Low Stubbin Colliery, Rawmarsh, Rotherham. 

Nbwey, J. W., Welliagton Road, Dudley, Worcestershire. 

Newton, James, Whitehaven Colliery, Whitehaven. 

Newton, John, Longport, Stoke-upon-Trent. 

Nichol, Wm., De Beers Mine, Kimberley, South Africa. 

Nichoi^son, a. D., Lane Ends, Hetton-le-Hole, R.S.O., Co. Durham. 

Nicholson, J. H., Cowpen Colliery Office, Blyth, Northumberland. 



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LIST OF MEMBERS. XXXVU 

NiOHOiiSOir, Marhhall, Middleton Colliery, Leeds. 

Nixon, John, Stafford Coal and Iron Co., Stoke -upon-Trent 

NoBUB, Thomas Geobob, Sacriston Colliery, Durham. 

North, F. W., Rowley Hall Colliery, Dudley, Staffordshire. 

NoBTH Bbancepsth Coal Co., Limitkd, Crown Street Chambers, Darlington. 

North Hstton Colliery, Owners of. Fence Houses. 

NowsLL, William, Haunchwood Colliery, Nuneaton. 

Oakbs, C. H., Holly Hunt, Alfreton. 

Oatks, Robert J. W., Rajdoha Mining Co., Limited, via Kandra P.O., Bengal 
Nagpor Railway, Bengal, India. 

Offer, Stephen, Cheadle Park Colliery, Cheadle, Staffordshire. 
*OoDEN, J. M., 40, West Sunniside, Sunderland. 

Ogilvis, a. Graeme, 8, Grove End Road, St. John's Wood, London. 

Oldham, George, 25, Western Hill, Durham. 

Oliysr, C. J., Spring Vale, Spital, Chesterfield. 

Ormerod, Edward, Atherton, Manchester. 

Ornsbt, R. E., Seaton Delaval Colliery, Newcastle-upon-Tyne. 

O'Shsa, L. T., Firth College, Sheffield. 

Oswald, R. P. W., H.M. Inspector of Mines, Hensingham, Whitehaven. 

Ottewsll, Draper, The Gardens, Osmaston Road, Derby. 

Overend, James, Mining Offices, Bamsley. 

Owen, William, Bucknall, Stoke-upou-Trent. 
*OxiiET, Joshua, Wombwell Main Colliery, Barnsley. 

Page, F. W., Black well Collieries, Alfreton. 
Pauier, A. S., Highfield House, Gateshead-upon-Tyne. 
Palmer, C. B., Usworth Colliery, Washington, R.S.O. 
Palmer, Sir Chas. Mark, Bart., M.P., Quay, Newcastle-upon-Tyne. 
Palmer, Henry, East Howie Colliery, near Ferryhill. 
Pamelt, C, 21, Morgan Street, Pontypridd, South Wales. 
Panton, F. S., Silksworth Colliery, Sunderland. 
Parker, Henrt, Etruria Hall, Hanley, Staffordshire. 
Parkin, J., Rylands Main Colliery, Bamsley. 
Parkin, L. C, Rylands Main Colliery, Bamsley. 
Parkinson, W., 6, Ivy Terrace, South Moor, Cheater -le-S tree t. 
Parrinoton, M. W., Wearmouth Colliery, Sunderland. 
Parrt, D. E., Norton Cannock Colliery, Bloxwich, Walsall. 
Parry, Evan, Wharaoliffe Woodmoor Colliery, Bamsley. 
Parsons, Hon. Charles Algernon, Elvaston Hall, Ryton-upon-Tyne. 
Parton, Arthur, Willenhall, Wolverhampton. 
Pasfield, T., 5, Victoria Terrace, Dudley, Worcestershire. 
Patrick, J. A., West Pool Villas, Saltergate, Chesterfield. 
Patterson, Thomas, Craghead, Chester-le- Street. 
Patterson, Wm., Front Street, Tynemouth. 
Pattison, Wm., Morley Main Colliery, Morley, near Leeds. 
Payton, Edmund, Yew Tree House, Morleston Street, Derby. 
*Peace, M. W., King Street, Wigan, Lancashire. 
Peacock, Thomas, Shelton Collieries, Brook Street, Hanley. 
Peacock, W. F., Horsley Collieries, Tipton. 
PsAKE, H. C, Walsall Wood Colliery, WalsalL 



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XXZViil LIST OF MEMBERS. 

Peaks, John Nash, Tunstoll, Staffordshire. 
Peakx, R. C, Cumberland House, Redboum, Herts. 
p£ABSOH, Alexander, Parkhouse Colliery, Chesterton, Staffordshire. 
PsAESON, James, Brampton Manor, Chesterfield. 
Peabson, Johnson, The Red House, Whittington, Chesterfield. 
Pearson, Joseph, Hugglescote, Ashby-de-la-Zouch. 
Pease, Arthur, Darlington. 

Pease, Sir J. W., Bart., M.P., Hutton Hall, Guisbrough, Yorkshire. 
Peasoood, W. G., Leycett, Newcastle, Staffordshire. 
Pedeltt, SiM'tN, Clara Vale, Ryton-upon-Tyne. 
Peel, Robert, New Brancepeth Colliery, Durham. 
Peils, William, Croft Hall, Moresby, Whitehaven. 

Pendleton, W. B., Harris Road, Five Dock, near Sydney, New South Wales. 
Perciyal, Charles, Linton, Burton-upon-Trent. 
PsBCiVAL, Joseph, Netherseal Colliery, Burton-upon-Trent. 
Percy, R. F., 6, Birkland Avenue, Nottingham. 
Perot, W. R., Rock House, Bamsley. 
Perkins, Charles, Gallowhill Hall, Newcastle-upon-Tyne. 
Phillips, John, West Bromwich. 

Phillips, W. G., Ansley Hall Colliery, Atherstone, Warwickshire. 
Pickup, P. W., 71, Preston New Road, Bkkckbum. 

PiooFORD, Jonathan, Stanton Ironworks (Limited) Co.'s Collieries, near Mans- 
field. 
Plowbioht, Robert, Brampton Ironworks, Chesterfield. 
Plummer, John, H.M. Inspector of Mines, Bishop Auckland. 
Pollard, John, Central Chambers, King Street, Wakefield. 
Poole, Henry, 279, Edge Lane, Liverpool 

Poole, H. Skiffinoton, Acadia Coal Company, Limited, Stellarton, Nova Scotia. 
Poole, P. G., Klerksdorf, South African Republic. 
Pope, Philip Henry, Basford, Stoke-upon-Trent. 
PoPHAM, J. L., c/o Messrs. Hewitt and Bobart, London Road, Derby. 
Potter, Addison, C.B., Heaton Hall, Newcastle-upon-Tyne. 
Potter, A. M., Riding Mill-upon-Tyne. 
Potter, C. J., Heaton Hall, Newcastle-upon-Tyne. 

Prest, J. J., Shelton Iron, Steel, and Coal Co., Limited, Stoke-upon-Trent. 
Prestwick, J., IrwoU Park, Eccles, Manchester. 
Price, John, 6, Osborne Villas, Jesmond, Newcastle-upon-Tyne. 
Price, J. H., Rowley Regis, Dudley, Worcestershire. 

Price, S. R., c/o Messrs. Forster Brown and Rees, Guildhall Chambers, Cardiff. 
Priestley, J. G., Glass Houghton Colliery, Castleford. 
Prime, Enoch, Skegby Colliery, Mansfield. 
Prinolb, Edward, Choppington Colliery, Northumberland. 
Prinole, Hy. Geo. , Tanfield Lea Colliery, lintz Green Station, Newcastle-upon-Tyne. 
Pbingle, T., Tanfield Lea Colliery, Lintz Green. 
Prior, Edward G., Victoria, British Columbia. 
Proctor, J. H., 29, Side, Newcastle-upon-Tyne. 
Pughe, W. a., Scarsdale House, Loscoe, Codnor, Derby. 
PuRCELL, S., Monck HiU, Pontefract. 

Ramsay, J. A., Sherbum and Littletown Collieries, near Durham. 
Ramsay, J. G., Page Bank Colliery, Willington, Co. Durham. 



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LIST OF MEMBERS. XXXIX 

Rakbat, W., Turadale, Co. Durham. 

Kangslkt, W. H., Stafford House, Chesterfield. 

Ratclifvr, Hknby, Bryukinalt Colliery, Chirk, North Wales. 

KATCLirFE, William, Apedale, near Newcastle, Staffordshire. 

RAYfNswoiiTH, The EUbl of, Ravensworth Castle, Gateshead -upon-Tyne. 

Rbdmaynb, R. a. S., Seaton Delaval Colliery, Newcastle-upon-Tyne. 

Rkes, Habbt, Normacot, Longton, Stoke upon-Trent. 

Rkid, Alexander, Caergwrle, Wrexham. 

Rbid, Andrew, Printing Court Buildings, Newcastle-upon-Tyne. 

Rbid, Francis, 13, Railway Arches, Westgate Road, Newcastle-upon-Tyne. 

Rbid, P. S., 20, John Street, Adelphi, London, W.C. 

Rbnshaw, W. R., Phoenix Foundry and Boiler Works, Stoke- upon-Trent. 

Rhodes, C. £., Aldwarke Main and Car House Collieries, Rotherham. 

Rhodes, Jeremiah, Shirland Colliery, Alfretou. 

Rich, Wm. , Minas de Rio Tinto, Provincia de Huelva, Spain. 

Richardson, A. M., 44, Victoria Road, Leeds. 

Richardson, H., Backworth C-oUiery, Newcastle-upon-Tyne. 

Richardson, R., Blaydon Main Colliery, Blaydon-upon-Tyne. 

Richardson, Ralph, Whitburn Colliery, South Shields. 

Richtsr, F., Osborne Villas, Newcastle-upon-Tyne. 
Ridley, G., 16, Dean Street, Newcastle-upon-Tyne. 
Ridley, G. D., Tudhoe Colliery, Spennymoor. 

Ridley, J. C, 3, Summerhill Grove, Newcastle-upon-Tyne. 

Ridley, Sir Matthew White, Bart, M.P., Blagdon, Northumberland. 
RiDYARD, J., Bridgewater OfGlces, Walkden, near Bolton-le-Moors, Lancashire. 

RiOBY, Frank, AUager, Stoke-upon-Trent. 

Rrson, J. R., Jcsmond Gardens, Newcastle-upon-Tyne. 

RiTSON, U. A., Queen Street, Newcastle-upon-Tyne. 

RiTSON, W. A., Crumpsall, Manchester. 

Roberts, J. H., Woodroyd, Qonley, Huddersfield. 

Roberts, Samuel, Park Grange, Sheffield. 

Roberts, Thomas, BrownhlUs Colliery, Tunstall, Staffordshire. 

Robertson, D. A. W., Metropolitan Colliery, Helensburgh, near Sydney, N.S. W. 

Robertson, Dr. J. R. M., Linton, Mitsons' Point, Sydney, N.S.W. 

Robertson, W., 123, St. Vincent Street, Glasgow. 

Robinson, F. K., EUistown Collieries, near Leicester. 

Robinson, G. C, Brereton and Hayes Colliery, Rugeley, Staffordshire. 

Robinson, Gboroe L., Adderley Green, near Longton, Staffordshire. 

Robinson, Greenwood, High Street, Birstal, Leeds. 

Robinson, J. G. 

Robinson, John Thomas, Beechburn Colliery, Crook, R,S.O., Co. Durham. 

Robinson, R, Howlish Hall, near Bishop Auckland. 

Robinson, R. H., Mundy Street, Heanor, Nottingham. 

Robinson, Thomas, 7, Carlisle Street, Dresden, Longton, Staffordshire. 

RoBSON, D. W., Eighton Lodge, Low Fell, Gateshead-upon-Tyne. 

RoBSON, J. S., Butterknowle Colliery, via Darlington. 

RoBSON, Thomas, Wigan and Whiston Coal Co. , Limited, Proscott. 

RoBSON, T. O., Chowdene Cottage, Low Fell, Gateshead-upon-Tyne. 

EoBSON, William, Walker Colliery, Walker-upon-Tyne. 

Rochkster, W., River View, Blaydon-upon-Tyne. 

Rogers, D., Dudley Road, Tipton, Staffordshire. 



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Zl LIST OF HEMBBRS. 

RooEHSoK, John, Croxdale Hall, Durham. 

RoN'ALDSON, J. H., Mount Kembla Colliery, WoUongong, New South Wales. 
RoNTREB, T., South Boldon, Newcastle-upon-Tyne. 
Roper, T., Barbors Field, Bilston. 

RosGAMP, J., Shilbottle Colliery, Lesbury, R.S.O., Northumberland. 
Ross, Hugh, Croxdale Cjlliery Office, Durham. 
RossER, W., Rhydyrhelig, Sketty, Swansea. 
RoTHWELL, R. P., 27, Park Place, New York, U.S.A. 
RouTLEDOE, Jos., Greeubank, Chester-le-Street. 
RouTLBDOE, J. L., Waterloo Main Colliery, near Leeds. 
RouTLEDOE, R., Garforth Colliery, Leeds. 
RouTLEDOE, W. H., The Rhyd, Tredegar, Monmouthshire 
Rowan, James, Inspector of Collieries, WoUongong, New South Wales. 
RusooE, John, Hyde, near Manchester. 
RussBLL, RoBT., Coltness Iron Works, Newmains, N.B. 
Rutherford, W., South Derwent Colliery, Annfield Plain, lintz Green. 
Ryder, W. J. H., Messrs. Mills and Sons, Collingwood Street, Newcastle-upon- 
Tyne. 
Ryhopb Coal Company, Ryhope Colliery, near Sunderland. 

Sadler, F. C, Oldland Colliery, Oldbmd Common, near Bristol 

Saint, G., Vauxhall Colliery, Ruabon, North Wales. 

Saise, Walter, E.I.R. Collieries, Giridi, Bengal, India. 

Salmond, Walter, Pinxton Collieries, Alfreton. 

Samborne John Stctkely Palmer, The Llandyry Anthracite Colliery Company, 

Limited, near Kidwelly, South Wales. 
Sankby, W. H., Morley Hall, Derby. 
Savage, A. T. C, Tibshelf Collieries, Alfreton. 
Sawyer, A. R., c/o Messrs. Thompson, Watson, and Co., Cape Town, South 

Africa. Transactions to 40, Brompton Square, London, S.W. 
Saxton, I. H., Hasland Green, Chesterfield. 
SoARTH, W. T., Raby Castle, Staindrop, Darlington. 
Sohofield, C. J., Clayton, near Manchester. 
SCHOLBFIELD, JoHN, Hcmsworth, Wakefield. 

SCHRAM, RiOHARD, 17a, Great George Street, Westminster, London, S.W. 
ScoTT, Andrew, Broomhill Colliery, Acklington. 
ScoTT, C. F., Grove Cottage, Leadgate, Co. Durham. 
SooTT, E. Charlton, Rainton Colliery, Fence Houses. 
Scorr, Ernest, Close Works, Newcastle-upon-Tyne. 
Scott, F. W., Atlas Wire Rope Works, Reddish, Stockport. 
Soott, J. S., Trimdon Hall, Trimdon Grange, R.S.O., Co. Durham. 
Scjorr, Wm., Thomhill Collieries, near Dewsbury. 
SooTT, William, Hanley, Staffordshire. 
SoouLAR, G., Cleator Moor, via Carnforth. 

ScRAOO, William, The Hanley CoUiery Co., Hanley, Staffordshire. 
Scrivener, Edward £., The Cedars, Brampton, Newcastle, Staffordshire. 
ScURFiELD, George J., Hurworth-upon-Tees, Darlington. 
Sbely, Charles, Shemt'ood Lodge, Arnold, Notts. 
Sbbly, C. H., Sherwood Lodge, Arnold, Notts. 
Sbohill Colliery, Owners of, Seghlll, Northumberland. 
Selby, Atherton, Leigh, near Manchester. 



Digitized by VjOOQ IC 



UgT OF MBMBSBS. zli 

Sblkikk, J. 6., Dalton-in-Fnmen. 

Sbmiob, a., Birk Honae, Bftrnaley. 

Settle, Joel, Madeley Coal and Iron Co., Newcaaile, Staffordshire. 

Settle, Miles, Daroy Lever GoUieriee, near Bolton. 

Skybrn, Thomas, Clifton Colliery, Nottingham. 

Skybbs, Wm., Beamish View, via Chester-le-Street 

Setmouil, L. Irving, Be Beers Consolidated Mines, Kimberley, South Africa. 

Sbaw, Charles, Jan., 26, West Parade, Mount Pleasant, Stoke-npon-Trent. 

Shaw, Edgar H., Adderley Qreen Collieries, Stoke-upon-Trent. 

Shaw, G., Wath Main Colliery, Rotherham. 

Shaw, John, Cramlington Colliery, Northumberland. 

Shaw, John, Darriagton Hall, Pontefract. 

Shaw, J. Leslo, Somerset House, Whitehaven. 

Shaw, Savills, Durham College of Science, Newoastle-npon-Tyne. 

Shaw, W., Wellington Cast Steel Foundry, Middlesbrough. 

Sheldon, John, Bastwood, Nottingham. 

Shxnton, Jambs, 80, Broadwell Road, Oldbury. 

Shenton, John, Silverdale, Staffordshire. 

Shiel, John, Framwellgate Colliery, Co. Durham. 

Shiplet, T., Castle Eden CoUiery, Castle Eden Station. 

Shone, Isaao, Great George Street Chambers, Parliament Square, London, S. W. 

Shore, Thomas, Ireland Colliery, Staveley, Chesterfield. 

Shore, Thomas, Shelton, Stoke-upon-Trent. 

Shore, Wm. Martin, Kaitangata Railway and Coal Co.'s Collieries, Otago, New 

Zealand. 
Short, W., Lambton Colliery, Newcastle, New South Wales. 
Shufflebothan, Daniel, Biddulph Valley Collieries, Stoke-up on-Trent. 
SiDEBOTHAM, J. N., 1, Princcss Street, Albert Square, Manchester. 
Silvester, Fred., Thistleberry. Newcastle. Staffordshire. 
Silvester, Harbt, Castle Hill Foundry, Newcastle, Staffordshire. 
Silvester, J. C, Castle Hill Works, Newcastle, Staffordshire. 
SiMPKiN, J. W., Midsomer Norton, Bath. 

Simpson, C. L., Engine Works, Grosvenor Road, Pimlico, London. 
Simpson, F. L. G., Mohpani Coal Mines, Gadawarra, C.P., India. 
Simpson, F. R., PeUall Colliery, near WalsalL 
Simpson, J., Heworth Colliery, Felling, R.S.O., Co. Durham. 
Simpson, J. B., Hedgefield House, Blaydon-upon-Tyne. 
Simpson, Nelson Ashbridqe, Hedgefield House, Blaydon-upon-Tyne. 
Simpson, R., Moor House, Ryton-upon-Tyne. 
Skinner, Samuel, Throapham Manor, Rotherham. 
Slaok, J., Rockingham Colliery, Bamsley. 

Sladden, Harry, 65, Bamato Buildings, Johannesburg, So uth Africa. 
Slinn, T., Plashetts Colliery, Falstone, Northumberland. 
Smallman, Reuben, Camp Hill Grange, Nuneaton. 
Smith, Alexander, Colmore Chambers, 3, Newhall Street, Birmingham. 
SmTH, C. Sebastian, Shipley Collieries, Derby. 
Smith, Eustace, Newcastle-upon-Tyne. 
Smith, G. E., 68, Mapperley Road, Nottingham. 
Smith, H., Hull. 

Smith, Joseph, 26, St. James* Street, Nottingham. 
Smith, J. B., Newstead Colliery, Nottingham. 



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Xlii LIST OF MBMBEB& 

Smith, R. Cliffobd, Ashford Hall, BakewelL 

Smith, Sydney A., 1, Princes Street, Albert Square, Manchester. 

Snbll, Albion T., Brightnde, Salisbury Road, Brondesbury, London, N.W. 

Snow, Charles, Glapwell Colliery, near Chesterfield. 

Snowball, Franois John, Seaton Bom House, Dudley, Northomberland. 

Soar, Charles, Granville Colliery, Burton-upon-Tront. 

SoFWiTU, Arthur, Cannock Chase Collieries, near Walsall. 

South Hbtton and Murton Collieries, Owners of, 50, John Stoeet, Sunderland. 

Sodthall, a. B., Monckton Main Colliery, Bamsley. 

SouTHALL, William, Park Hall Colliery, Cheadle, Staffordshire. 

Southern, E. 0., Ashington Colliery, near Morpeth. 

Southern, J., Heworth Colliery, Newcastle-upon-Tyne. 

Southern, R., Burleigh House, The Parade, Tredegarville, Cardiff. 

Southern, T. A., Ill, Rose Hill Street, Derby. 

SouTHWORTH, Thos., Hindley Green Collieries, Wigan. 

Sparkbs, J., Jnn., Chester Park, Fishponds, BristoL 

Spence, R. F., Backworth, R.S.O., Northumberland. 

Spenobr, F. H., Robinson Gold Mining Company, Witwatersrand, Z.A.R. 

Spencer, George, Stanley Lodge, West Hallam, near Derby. 

Spencer, J., Globe Tube Works, Wedneebury. 

Spencer, John, Westgate Road, Newcastle-upon-Tyne. 

Spencer, T., Ryton, Newcastle-upon-Tyne. 

Spencer, William, Southfields, Leicester. 

Spooner, Georoe, Cortonwood Colliery, Bamsley. 

Spruce, Samuel, Beech House, Tamworth. 

Spruce, Titus, Lennox Road, Florence, Longton, Staffordshire. 

Spry, John, Murton Colliery, Co. Durham. 

Standlky, William, Nuneaton. 

Stanikr, Francis, Peplow Hall, Salop. 

Stanley, Reginald, Nuneaton Colliery, Nuneaton. 

Stansfeld, Harold Sinclair, Flockton Manor, Wakefield. 

Stanton, Philip, Throckley Colliery, near Newcastle-upon-Tyne. 

Statham, William, Field House, Chesterton, Newcastle, Staffordshire. 

Stear, J., Strafford Colliery, Bamsley. 

Steayenson, a. L., Durham. 

Steavenson, C. H., Brotton Mines, Brotton, R.S.O., Yorks. 

Stechert, G. £.. 30, Wellington Street, London, W.C. 

Steele, Richard, Hanley, Staffordshire. 

Stella Colliery, Owners of, Hedgefield, Blaydon-upon-Tyne. 

Stephenson, G. R., 9, Victoria Chambers, Westminster, London, S. W. 

Stephenson, W., Garesfield Colliery, Lintz Green. 

Stevens, A. J. , Uskside Iron Works, Newport, Monmouth. 

Stevenson, Henry, Portland Collieries, Kirkby-in-Ashfield, Nottingham. 

Stobart, F., Biddick Hall, Fence Houses. 

Stobart, H. T., Wearmottth Colliery, Sunderland. 

Stobart, W., Pepper Arden, Northallerton. 

Stobart, W. R., Etherley Collieries, Co. Durham. 

Stobbs, J. T., Walker Colliery, Walker-upon-Tyne. 

Stoker, Arthur P., Birtley, near Chester-le-Street. 

Stoker, Henry, 5, Argyll Mount, Mansfield. 

Stones, George B., Dale View, Conisbro', Rotherham. 



Digitized by VjOOQ IC 



LIST OF MBMBEBS. xliii 

SiORET, Thos. E., Longton Hall Collieries, Longton, Staffordshire. 

Steachan, Alexandeb, 131, Station Street, Burton-upon-Trent. 

Stkakbr, J. H., Howdea Dene, Corbridge-upon-Tyne. 

Stratton, T. H. M., Cramlington House, Northumberland. 

Stbsatfieijd, Hugh S., Ryhope Colliery, near Sunderland. 

Street, Joh^, High Street, Silverdale, Staffordshire. 

Stbick, John, Bar Hill, Madeley, Staffordshire. 

Strick, R. J., Cossall Colliery, Nottingham. 

Strtok, Thomas Shephard, Bar Hill, Madeley, Staffordshire. 

Stroud, Prof H., Durham College of Science, Newcastle-upon-Tyne. 

Stuart, C. M., St. Dunstan's College, Lewisham. 

Stubbs, Thomas, Aldwarke Main Colliery, Rotherham. 

Sutton, William, Kinsley, Hemsworth, Wakefield. 

Swallow, J., Bushblades House, Lintz Green, Newcastle-upon-Tyne. 

Swallow, J. F., Mosboro' Hill House, Eckington, Rotherham. 

SwAUiOW, R. T., Wardley Hall, Newcastle-upon-Tyne. 

Swan, H. F., North Jesmond, Newcastle-upon-Tyne. 

Swan, J. G., Upsall Hall, near Middlesbrough. 

Swan IT, Frank, Annesley, Nottingham. 

Sword, J. G. 

Stkes, Frank K., Springwell Villa, Bishop Auckland. 

Sykjs, Thomas, Soho Iron Works, Pollard Street, Manchester. 

Tate, Henry, Talk-o*-th'-Hill Colliery, Stoke-upon-Trent. 

Tate, Simon, Trimdon Grange Colliery, Co. Durham. 

Tate, William, West Ardsley Collieries, Wakefield. 

Taylor, Hugh, King Street, Quay, Newcastle-upon-Tyne. 

Taylor, J. A., Spa House, Treeton, Rotherham. 

Taylor, John Hy., Borough Sur>'eyor, Bamsley. 

Taylor, Joseph, 134, Leek New Road, Hanley, Staffordshire. 

Taylor, Joseph H., 61, Attwood Street, Kidsgrove, Staffordshire. 

Taylor, T., Quay, Newcastle-upon-Tyne. 

Taylor, William, libberton Grange, Newport, Salop. 

Taylor-Smith, Thomas, Broadwood Park, Lanchester, Co. Durham. 

Teale, W. E., Swinton, near Manchester. 

Teasdale, T., Middridge, via Heighington, R.S.O. 

Telford, W. H., Hedley Hope Collieries, Tow Law, R.S.O., Co. Durham. 

Tellwrioht, William A. M., The Beeches, Wolstanton, Stoke-upon-Trent. 

Tennant, William, Stoke-upon-Trent. 

Tebry, S. H., 17, Victoria Street, Westminster, London, S. W. 

Thirkell, E. W., Oaks Colliery, Bamsley. 

Thomas, R., Bloxwich, Walsall. 

Thomas, W., Penelvan, Camborne, Cornwall 

Thompson, Charles Lacy, Farlam Hall, Milton, Carlisle. 

Thompson, Edward, Norton Collieries, Stoke-upon-Trent. 

Thompson, Ernest A., 13, Wellington Terrace, South Beech, Blackpool. 

Thompson, Joseph, 38, Church Street, Murton Colliery, Sunderland. 

Thompson, Matthew E., Chatterley Iron Works, Chatterley, near Tunstall, 

Staffordshire. 
Thompson, R., Jun., 19, The Crescent, Gateshead-upon-Tyne. 



Digitized by VjOOQ IC 



Zliv LIST OF MBMBBBS. 

Thompson, W., Roos Buildings, Charters Towers, North Queensland, Australia. 

Thoicson, John, Eston Mines, by Middlesbrough. 

Thomson, Jos. F., Manvers Main Colliery, Wath-upon-Deame, Rotherham. 

Thornewhx, Robert, Engineering Works, Burton-upon-Trent. 

Thbooklet Colliery, Owners of, Newcastle-upon-Tyne. 

Tinker, J. J., Hyde, Manchester. 

TiNN, Jos., Ashton Iron Rolling Mills, Bedminster, Bristol. 

Todd, Jambs, Elvet Bridge, Durham. 

Todd, John T., Bedford Lodge, Bishop Auckland. 

Todd, W. G., Nunnery CoUiery Offices, Sheffield. 

ToMLiN, John, GranvUle Colliery, Burton-upon-Trent. 

ToMUNSON, John, Pilsley Colliery, Clay Cross, Chesterfield. 

ToFLET, Wm., 28, Jermyn Street, London, S.W. 

TouzEAU, E. M., Leadenhall Buildings, Leadenhall Street, London, E.C. 

TowNSEND, Hy. Geo., St. John's Colliery, Normanton. 

Trbolown, C. H., Wretham Road, Handsworth, Birmingham. 

Tbelease, W. Henwood, Pestarena, Vail Anzasca, Novara, Italy. 

TuRBUTT, W. G., Ogston Hall, Alfreton. 

TuRNBULL, Robert, South Kirkby Colliery, Wakefield. 

Turner, D. N., c/o Messrs. Hewitt and Bobart, London Road, Derby. 

Turner, G. R., Langley Mill, Nottingham. 

Turner, John, Moira Colliery, Ashby-de-la-Zouch. 

Turner, William Jepson, The Cedars, Stanley, Derbyshire. 

Twioo, R., East Cannock Colliery, Hednesford. 

Tyas, a., Swaith, near Bamsley. 

Tyers, John E., Nerbudda Coal and Iron Company, Limited, Mohpani Coal 

Mines, via Gadawarra, C. Provinces, India. 
Tyzack, D., 71, Westgate Road, Newcastle-upon-Tyne. 

Varley, John, Park View, Hill Top, Eastwood, Notts. 
Varty, Thomas, Skelton Park Mines, Skelton, R.S.O., Cleveland. 
Vaughan, Cedric, Hodbarrow Iron Ore Mines, Millom, Cumberland. 
Victoria Garesfield Colliery, Owners of, c/o George Peile, Shotley Bridge, 

Co. Durham. 
YiQOJkSSf Benjamin D. , Hope Cottage, Downing Street, Silverdale, Staffordshire. 
ViooARS, Matthew Henry, Knutton Farm, Newcastle, Staffordshire. 
ViTANOFF, Geo. N., Sophia, Bulgaria. 
Vivian, John, Vivian's Boring and Exploration Co. , Ltd. , 42, Lowther Street, 

Whitehaven. 
VuiLLEBHN, E., Mines d'Aniche, Nord, France. 

Waddle, H., Llanmore Iron Works, Llanelly, South Wales. 
Wade, R. A., Pinxton CoUiery, Alfreton. 
Wadham, E., Millwood, Dalton-in-Fumess. 

Wain, Edward B., Whitfield Collieries, Norton-le-Moors, Stoke-upon-Trent. 
Wain, Joseph, The Chatterley Iron Co., Bucknall Collieries, Bucknall, Stoke- 
upon-Trent. 
Wain, Joseph, Hulrae Colliery, near Longton, Staffordshire. 
Wain, J. R., Chatterley Iron Co., Tunstall, Staffordshire. 
Wain, Wm. Holt, 56, Stoke Road, Shelton, Stoke-upon-Trent. 
Wainwright, GEO.,Sladderhill, Chesterton, Staffordshire. 



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LIST OF MSMBBBB. zlv 

Wales, H. T., 104, St. Mary Street, Cardiff. 

Wauceb, G. Btakb, Whamcliffe SUkstone Colliery, Bamaley. 

Walker, J. S., Pagefield Iron Works, Wigan, Lanoashire. 

Walker, Sydney Ferris, 196, Severn Road, C4uiton, Cardiff. 

Walker, W., Hawthonu, Saltbnm-by-the-Sea. 

Walker, William, Forest View, St. George's Hill, Coleorton, Ashby-de-la- 

Zouch. 
Walker, Wm., Jan., H.M. Inspector of Mines, Durham. 
Walker, W. E., Dudley, Worcestershire. 
Walker, William Edward, Lowther Street, Whitehaven. 
Wall, George, South Church, Bishop Auckland. 
Wallace, Henry, Trench Hall, Gateshead-upon-Tyne. 
Wallace, J., King Street, Wigan. 

Wallau, Jacob, Messrs. Black, Hawthorn, and Co., Gateshead-upon-Tyne. 
Walters, Hasoraye, Birley Collieries, Sheffield. 
Walters, J. T., Babbmgton Collieries, Nottingham. 
Walters, R. G., Shirtcliff House, Woodhouse, Sheffield. 
Walton, James, 23, Queen Street, Newcastle-upon-Tyne. 
Walton, J. Coulthard, Writhlington CoUiery, Radstock, via Bath. 
Walton, M., Dearham Colliery, Carlisle. 

Walton, W. W., Croft Cottage, Ferryside, near Carmarthen, South Wales. 
Warburton, J. S., 49, New Road, Greys, Essex. 
Ward, F. L., Unstone Colliery, Sheffield. 
Ward, H., Rodbaston Hall, near Penkridge, Stafford. 
Ward, T. H., Burma Coal Co., Letkobin, Ihingadaw Circle, Shwebo, Upper 

Burma, East Indies. 
Ward, W., Churwell Colliery, Leeds. 
Wardell, S. C, Doe Hill House, Alfreton. 
Wardle, Richard, Dunsil House, Fackley, Mansfield. 
Wardle, W., West Cannock Colliery, Hednesford. 
Waring, G. W., Green Hill, Longshaw, Billinge, near Wigan, 
Warrington, Henry, Berry Hill Works, Stoke-upon-Trent. 
Warrington, Jambs Henry, Berry Hill Works, Stoke-upon-Trcnt. 
Washington, W., Mitchell Main Colliery, Bamsley. 
Waterhouse, M. W., Glass Houghton Colliery, Castleford. 
Waterman, Wm. John, Manchester Road, Sheffield. 
Watkyn-Thomas, W., Mineral Office, Cockermouth Castle. 
Watson, Edward, 19, Bloomfield Terrace, Gateshead-upon-Tyne. 
Watson, John, 19, Bloomfield Terrace, Gateshead-upon-Tyne. 
Watson, Simeon, New Hucknall Colliery, Mansfield. 
Watson, T., Trimdon Colliery, Trimdon Grange. 
Watts, John, Edensor Street, Chesterton, Staffordshire. 
Wearmouth Colliery, Owners of, Sunderland. 
Webster, H. Ingham, Morton House, Fence Houses 
Weeks, J. G., Bedlington, R.S.O., NorthumberLmd. 
Weeks, R. L., Willlngton, Co. Durham. 
Weightman, Percy O., Garforth Collieries, near Leeds. 
Wells, W. E., Eckington Collieries, Rotherham. 
Wbstmaoott, p. G. B., ELswick Ironworks, Newcastle-upon-TS^e. 
Westport Coal Co., Limited, Manager, Dunedin, New Zealand. 
Wheatley, Samuel, Nailstone Colliery, Leicester. 
Whbatly, Samuel W., Butterton, Newcastle, Staffordshire. 



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Xlvi LIST OF KSMBKBg. 

White, C. E., Hebbani Colliery, Hebbitm-apon-Tyiie. 

White, H., Walker Colliery, Newcafltie-npon-Tyne. 

White, L W. H., Woodlesford, near Leeds. 

White, J. F., Weetgate, Wakefield. 

White, J. H. R., The Elms, Thringstone, Coalville, Leicester. 

Whitehead, James, Brindle Lodge, near Preaton, Lancashire. 

Whitehead, John, Jun., Penworthan Priory, Prestxm. 

Whitehead, John James, Arden Lea, Heaton, near Bolton, Lancashire. 

Wdttehouse, James. Burnt Tree, Tipton, Staffordshire. 

Whttehouse, W. H., Brownhills, WalsalL 

Whitelaw, John, 118, George Street, Edinborgh. 

Whittem, Thomas S., Wyken Colliery, near Coventry. 

WiDDAS, C, North Bitchbam Colliery, Howden, Darlington. 

Wight, Edwd. S., Hetton Colliery, Carrington, near Newcastle, New Sooth 

Wales. 
WiOHT, W. H., Cowpen Colliery, Blyth. 
Wilbbaham, Aabon, Mexboro' Colliery, Selstone, Alfreton. 
Wilde, William, Brockett House, Sharrow, Sheffield. 
Wilkes, John, Pelsall Foundry, Walsall, Staffordshire. 
Wilkinson, Horace, Black well Collieries, Alfreton. 
Wilkinson, J. R., Spark Lane, Mapplewell, Bamsley. 
Wilkinson, Thomas, Tinsley, near Sheffield. 

Williams, Edmund W., Henshall House, Goldenhill, Stoke-upcm-Trent. 
Williams, Ernest, P.O. Box 965, Bettelheim Buildings, Simmonds Street, 

Johannesburg, Z.A.R. 
Williams, Herbert Ionatius, Alsager, Stoke-upon-Trent. 
WiLUAMS, J., 115, Wellington Road, Dudley, Worcestershire. 
Williamson, J., Cannock and Rugeley Collieries, Hednesford, Staffordshire. 
WnjiiAMSON, J. H., Henshall House, Goldenhill, Stoke-upon-Trent. 
Williamson, J. T., Brownhills Colliery, Walsall. 
Williamson, R., Park Hill Colliery, Wakefield. 

Williamson, R. S., Cannock and Rugeley Collieries, Hednesford, Staffordshire. 
Williamson, Thomas, West Hallam Collieries, Hkeston. 
Willis, Henrt Stevenson, Sacriston, Durham. 

WiLBON, A. P., Mansion House Chambers, Queen Victoria Street, London, E.C. 
WnjBON, Benjamin, Florence Colliery, Longton, Staffordshire. 
WiLBON, Jaoob, Hucknall Huthwaite, Mansfield. 
WnjBON, J. B., Wingfield Iron Works and Colliery, Alfreton. 
WiLBON, J. D., Ouston House, Cheeter-le-Street. 
Wilson, John Robinson, H.M. Inspector of Mines, Leeds. 
WiusoN, Josh. M., St. John's Colliery, Normanton. 
WiusoN, Robert, Flimby Colliery, Maryport. 
Wilson, R. G., Pelton Colliery, Chester-le-Street 
Wilson, W. B., Thomley Colliery, by Trimdon Grange, Co. Durham. 
Wilson, W. E. C, Snibston Collieries, Coalville, near Leicester. 
WiNSTANLET, Petsr, Shaw Cross Colliery, near Dewsbury. 
Winbtanlet, Robt., 28, Deansgate, Manchester, 
Winter, T. B., Grey Street, Newcastle-upon-Tyne. 
WiNTERBonoM, W., Toversal, Mansfield. 
* Withers, Samuel, 26, Westgate, Mansfield. 



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LIST OF MBMBEBS. xlvii 

WiTTT, H. Stkss, Denaby Main Colliery, Mexboro', near Rotherham. 
WousTKNHOLME, M., Bestwood Pbrk, Bulwell, Notts. 
Wood, G. L., Freeland, Forgandenny, Perthshire. 
Wood, Ernest Setmouk, South Hetton, Sunderland. 
Wood, Johk, Coxhoe Hall, Coxhoe, R.S.O., Co. Durham. 
Wood, Lindsay, The Hermitage, Chester-le-Street. 

Wood, Thomas, North Hetton Colliery Office, Moorsley, Hetton-le-Hole, R.S.O. 
Wood, T. P., Market Phuse, Chesterfield. 
Wood, W. H., Coxhoe Hall, Coxhoe, Co. Durham. 
Wood, W. O., South Hetton, Sunderland. 
WooDUKAD, AiiF., Low Moor Ironworks, Bradford. 
WooDHKAD, L., Beeston Colliery, Leeds. 
Woods, Richard, Jessop Street, Codnor, Derby. 
WooDWOBTH, Benjamin, Heron Cross, Fenton, Stoke-upon-Trent. 
WooLUSOROVT, Frederiok, St. Peter's Chambers, Stoke-upon-Trent. 
Wordsworth, Robert, Warora Colliery, Central Provinces, India. 
Wordsworth, T. H., West Riding Collieries, Normanton. 
Wormald, C. F., May field Villa, Saltwell, Gateshead-npon-Tyne. 
Worth, F. G., British Water Gas Syndicate, Park Row, Leeds. 
*WoRTHiNOTON, J AMES, 11, Foley Place, Fenton, Stoke-upon-Trent. 
Wra7, C, fiO, Grantham Road, Bradford. 
Wrioht, Fitz-Herbert, The Hayes, Swanwick, Alfreton. 
Wriqht, Joseph, Arboretum Street, Nottingham. 
Wrightson, T., Stockton-upon-Tees. 
Wrob, James, Lidgett Colliery, Tankersley, Bamsley. 
Wroe, Jonathan, Wharncliffe Silkstone Colliery, Bamsley. 
Wynne, R. H., 19, Marsh Road, Newcastle, Staffordshire. 
Wynne, T. Trafford. 

Taxes, John, c/o MacVlillian, 6, Church Lane, Calcutta, India. 

Yeoman, T., Willington Colliery, Co. Durham. 

TouNO, John A., 7, Tyne Vale Terrace, Gateshead-upon-Tyne. 

Zumbuixwlon, G. C, 3, Astardji han, Grand Bazaar, Constantinople. 



fton^yederated. 

Armstrong, Prof. G. F., The University, Edinburgh. 

Blaikib, John, White Bam Colliery, Newcastle-under-Lyme. 

Buix, James, Cliffe Vale Ironworks, Stoke-upon-Trent 

CiJVE, Robert C, Clan way Colliery, Tunstall, Staffordshire. 

Freeman, T., Jun., 200, Phoenix Street, St. Pancras Station, London, N.W. 

Green, Prof. A. H., 137, Woodstock Road, Oxford. 

Hayes, William Prime, St. Mary's Place, Bury. 

HoLUS, H. W., Thomville House, Darlington. 

Homer, C. J., Ivy House, Stoke-upon-Trent. 

LoNOBOTTOM, L., Stoke-upon-Trent. 

Lucas, Jamss, Shelton Collieries, Stoke-upon-Trent. 



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Zlviii LIST OF MEXBBBS. 

MiALL, Prof. L. C, Yorkshire College, Leeds. 

Osborne, Chablis, 72, Piccadilly, Hanley, Stsflfordshire. 

Platt, Samukl R., Oldham. 

RucKEB, Prof. Ekbimoton, Claphain Park, London. 

RussBLL, R., Sea View, St. Bees, CamfcNrth. 

Thobpb, Prof. T. K, Science and Art Department, South Kensinnitou, 

London, S.W. 
Tbbglown, G. H., 2, St. John's Place, Wretham Road, Haadsworth. 
WooDALL, WiLUAM, Bleak House, Burslem, Stoke-npon-Trent. 



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TEANSACTIONS 

OF THB 

FEDERATED INSTITUTION 

OF 

MINING ENGINEERS. 



FEDERATED INSTITUTION OF MINING ENGINEERS. 



GENERAL MEETING, 

Held in thb Rooms op the Institution op Civil Engineers, 25, Gbeat 
GEOBaB Street, Westminster, Thursday, June 1st, 1893. 



Mb. GEORGE LEWIS, President, in the Chair. 



PRIZES. 

The Secretary announced that the President's prize of books had 
been awarded for the paper on 

" Mining in New Zealand." By Mr. G. J. Binns. 

The SsoRETARY farther announced that the Council had awarded 
prizes of books to the writers of the following papers : — 

'< Obseryatlona on Petiolenm in Eastern Europe, and the Method of Drilling 

for it." By Mr. A. W. Bastlake. 
"A General Description of the South Staffordshire Coal-field, south of the 

Bentley Fault, and the Methods of Working the Ten yard or Thick Coal." 

By Messrs. W. F. Clark and H. W. Hughes. 
" An Enquiry into the Cause of the Two Seaham Explosions, 1871 and 1880, 

and the Pochin Explosion, 1884." By Mr. T. H. M. Stratton. 



The President then read his address, as follows : — 



VOL. y^WML 



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PBESIDBN^TIAL ADDRESS. 



PRESIDENTIAL ADDRESS 



By Mb. GEORGE LEWIS. 



Following the precedent of previous years when your Presidents have 
addressed you, it is with pleasure that I purpose following in their footsteps ; 
presuming that I may hope, to some extent, to be able to interest you. 

The gentlemen who have preceded me in the office of President are well 
known as having gained their position by being men of sound judgment 
and ability ; and I fully appreciate the great honour of being associated 
with them in the office to which you have been good enough to elect me. 

The federation of the mining institutes of this country is only yet in 
its infancy, but we have had during the three years of its life, proof of its 
desirability in every stage of its progress. It fully bears out the adage of 
" unity is strength," even to a greater extent than we could possibly have 
supposed ; and, looking forward to the future, the time does not appear to 
me far distant when every local institution of the country will have seen 
the desirability of union, and become federated with us. There is every 
reason why this should be so ; and we may point with pardonable pride 
in support of this to our publications. I venture to say that never in 
the history of mining in this country has such progress before been made, 
neither have more reliable records been published than during the short 
period of our existence, and this more particularly during the past year. 
There is, as you are perfectly aware, a good reason for this ; and how 
much more preferable it must be, surely, that a paper upon which the 
writer would have to spend much valuable time and care should be 
published, not for the benefit alone of a small section of the mining 
community, but by an institution that would secure its publicity over the 
whole of the United Kingdom and in many districts beyond the sea where 
the members are located. Surely, I repeat, this is desirable, the object 
being worthy of our attention and continued exertions. 

I need scarcely point out to you what our objecl is, or at least my 
reading of it, for unless we have a definite object in view, and federate 
with the fiill intention of carrying out that object, we shaU gradually, 
although possibly slowly, as an institution cease to exist or accept a 
subordinate position. I maintain, however, we have an object, and that 
we are endeavouring to the best of our ability to further it. The 
improved education of all who are connected with the conduct of mines 



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PRESIBBNTIAL ADDHESR. 3 

of this oonnfciy is onr wish and intention ; not alone the younger 
branches, but those also who have passed from the tutored to the 
totorial stage, and must act on their own judgment and discretion. I 
maintain that to each one of these the publications of the Institution 
are of value ; and I venture to submit that they are frequently con- 
solted not only by the junior members of the Institution, but also by 
those who have had considerable experience in matters pertaining to 
mining work generally. 

We are informed through the Transactions of the progress made in 
mining engineering, of the new forces brought to bear upon the working 
of mines, of the various applications of machinery for, if not altogether 
novel purposes, at least novel in character, and of new ideas applied to 
the working or development of mines ; in addition to diffusing through 
our Institution a general geological knowledge of the various mining 
districts of the world. 

This I maintain is a work of considerable magnitude and importance, 
and one which is becoming more appreciated daily, and within a very 
short period will, I venture to hope and think, embrace every person in 
the United Kingdom connected with the supervision of mines. 

The education of the mining engineer of the future must of necessity 
be of greater importance than in the past, when the mines of this country 
were worked only from the outcrop or from shallow pits. It is of neces- 
sity that he should be cognizant of the fullest and latest information in 
reference to the path in life he has chosen to follow. When we come to 
consider the importance of the positions occupied, the large invested 
capital of which they have chaise, the lives which practically are 
entrusted to mining engineers, it appears to me that we as a body should 
not only suggest but insist that a most liberal curriculum be accorded 
to their education. It does not appear to me that any practical 
difficulty presents itself, and provided men of ability and education are 
to be drawn into the work (which to my mind is most desirable) ; they 
must upon entering it be assumed to occupy at least a position amongst 
the learned professions. 

Within the last twenty years the amount of capital necessary to win 
and work coal at any given colliery has increased very considerably, and 
this will still more be the case as the mines at the outcrop become 
exhausted — a probability which applies in a greater or less degree to 
all the mining of this country. Presuming, therefore, that a modem 
colliery with all the necessary machinery and other appliances, both 
sorface and underground, would cost, say, £100,000 (and there are many 



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4 PBESIDENTIAL ADDRESS. 

that have had expended upon them a smn equal to more than twice that 
amount), surely the person that has to expend this should have had 
the advantage of a most liberal training. To economically spend this 
money to commercial advantage he must have had experience not only in 
mining, but also be well versed in mechanical engineering. The winding, 
ventilating, and hauling power necessary must be well considered, and for 
this purpose a good mechanical knowledge is absolutely indispensable. 

I need scarcely point out that in the near future the whole or pretty 
nearly so of the collieries working coal at the outcrop will be exhausted, 
and their places can only be filled by sinking to greater depths and under 
very different circumstances both as r^ards capital, expenditure, and the 
diflficulties that would in aD probability be met with. Although we are 
not called upon to build a Tay bridge, still we are expected to be able to 
bore either a Channel or a Severn tunnel. Such works as these are being 
daily carried out by some one or other of our members, and under circum- 
stances equally as trying, and requiring for their satisfactory completion 
considerable mining experience. I maintain that many of the modem 
sinkings, of which the greater number of us have had some experience, 
are more difficult in their conception, arrangement, and successful com- 
pletion, than the Continental railway-tunnels that have of late years 
attracted so much notice in the engineering world. 

When we come to consider the immense amount of capital invested 
and the interests involved, I shall be able, I imagine, to show, not only 
that we ought to be able to conduct mining operations with due know- 
ledge, but also that our employers have a right to demand, and the 
public also, that the working of mines should be conducted upon lines 
that have been carefully thought out. 

When speaking of the amount of capital invested in mining in the 
United Kingdom, I am perfectly aware that I am treading upon debatable 
ground, and so far as I know there are no published official statistics 
upon the question. I am, however, of opinion that no less a sum than 
£1.50,000,000 is invested in mining, without taking into consideration 
the rolling-stock required to convey the produce to its destination, or in fact 
anything beyond the money expended upon and at the mines themselves. 

The Mining Royalties Commission, who have just issued their report, 
give us some valuable information, as it is now known that by the work- 
ing of mines, royalties were paid during the year 1892 to the amount of 
£4^667,048. 

I find that the number of persons employed in or about the mines of 
the United Kingdom during the year 1892 was 721,808, and according 



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FEESIDEKTUL ADDRESS. 5 

to my previous informaiit (the Mining Royalties Commission) that 
daring the year 1890, £43,000,000 was estimated to have been paid 
in wages to persons employed about them. 

Taking these figures as a basis we may, I consider, assume that 
upwards of 3,000,000 people in the United Kingdom are directly 
dependent upon the mining industry for a livelihood. 

This enormous industry, if I may so term it, is a larger employer of 
labour than all the railways of this country combined, which I believe only 
employ directly upon the lines themselves about 400,000 men, or only 
about one-half. This may possibly not apply to those indirectly employed 
by them, in the building of rolling-stock, locomotives, etc., neither do 
the mining statistics, because this part of the necessary work is carried out 
by independent firms who make a speciality of the manufacture of the 
articles required. 

I think these figures alone make out a case for our Institution, whose 
members have the practical control of this immense capital, and also the 
care of the lives of over 700,000 workmen. The time cannot be far 
distant when our federation will be complete, and I am suificiently 
sanguine that my successor in office will be able to report that we consist 
of every mining institute in the three kingdoms. 

In saying this I would like to point out, that in my opinion it would 
be very undesirable for any Institute to lose its individuality ; and I feel 
tolerably certain that all the objects we wish to obtain may be brought 
about without having removed from them their old names and other 
distinctive marks of originality. To these several Institutes our thanks 
as a body are especiaUy due, they having for years piloted us through 
rough water, a labour of which we are now reaping the advantage in 
various ways. 

The men who, to a great extent, are responsible for the lives of the 
workmen employed at their respective mines, appreciate their responsibility 
and are anxious for their welfare and safety. The number of fatal 
accidents in proportion to the number of persons employed has been 
decreasing for some years, and this I am inclined to suggest does not 
arise from the mines being less dangerous to work, or less inflamma ble 
gas being found in them, but from a cause otherwise explained, viz., a 
higher standard both of men, supervision, and discipline. There is no 
other means of obliterating in the future that great blot on our escutcheon 
— the explosions which periodically occur, a blot which, I am sure, is the 
wish and endeavour of each one of us, as far as we are able, to remove. 
That such a consummation may ultimately be brought about is our 
sincere desire. 



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6 PRESIDENTIAL ADDEESS. 

I need only refer my hearers to the continaons strides that have 
during the past generation been made in the education of the masses in 
this country, as a precedent for what we should seek to accomplish among 
ourselves. The education of the mining engineer should conform itself 
to the spirit of the times in which we live, a spirit which is certainly 
progressive. The idea originally was that only just sufficient educa- 
tion was necessary as to admit of its owner being able to discharge 
the ordinary duties of his profession; but looking to the marvellous 
advance of science, more particularly as applied to mining, he must be 
prepared to take advantage of every point that may probably be useful 
in the work which lies before him. 

After some little experience of the manner of holding the examina- 
tions for colliery managers^ certificates, and the result from what I may 
term the point of view of an interested party, I do not consider them on 
the whole satisfactory. In saying this I do not wish to be misunderstood, 
for I allude only to the system upon which the examinations are conducted, 
and my remarks do not in the slightest degree apply to the different 
boards of examiners or to the examiners themselves. You are aware that 
these boards are not in the first place agreed as to the age at which the 
aspirant should be allowed to hold a first-class certificate of competency. 
This appears to me very undesirable : the difference in age is two years, 
the Lancashire district being of opinion that at the age of 21 the mining 
student is competent, while in the Midlands the prescribed a^e is 23. 
Now, supposing each district had the power of refusing to allow the 
holder of a certificate whose examination took place where the age of 
21 was sufficient, to take charge of a colliery in that district where the 
minimum limit of age was 23, 1 could understand there might be some 
good reason for it, but in reality no such power exists. There are 
also other points upon which the examinations differ, when the object 
is very clearly stated to be for the same purpose, and it appears to me 
eminently desirable that there should be uniformity in every particular. 

The two classes of certificates may for a moment appear to constitute 
a difficulty, but this in reality is not so, the second class being fas always) 
intended to include men of a very much lower grade, acting under the 
instructions of the holder of the first-class certificate. 

The result of the working of the Coal Mines Regulation Act of 1873 
has been of great service in this respect, for it has done good if by only 
fixing the responsibility ; but it has accomplished far more than this. 
We have certainly found that men of a superior grade have been intro- 
duced, and with that a general reduction in the ratio of accidents as 
compared with the number of persons employed. 



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P&BSrDENTIAL ADDRESS. 7 

I would snggest that a central board, whose offices should be in 
London, have the control of all certificates of the first class, and that the 
examinations for these take place in London, The constraction of the 
board, I would suggest, should be upon the same lines as at present, 
but the number of members reduced, and each inspection district should 
be represented. 

The examiners should, as under the present Act of Parliament, be 
appointed by the board, but I would so far alter the present arrangement 
as to appoint professors of the various subjects, instead of as at present 
mining engineers, who examine upon all of them. 

The examiners should consist of the following, each taking their own 
special work, and should report as under the present Act to the board : — 
(1) a professor of mechanical engineering ; (2) a professor of chemistry ; 
(8) a professor of electricity; (4) a professor of mining engineering; 
(5) a board of mining engineers, consisting of one from each inspecting 
district comprised under the Coal Mines Regulation Act, to examine upon 
the technical subjects which may be desirable for the practical mining of 
his particular district ; and (6) the chief inspectors of mines. 

The boards, as at present constituted, should be empowered to grant 
certificates of the second class, and the candidates for these might be 
examined at the local centres as now arranged. 

It will have occurred to most of us, in the past twenty years 
during which the progress of mining has made such rapid strides, how 
absolutely necessary it is for those having the conduct of mines that they 
should be fully recognized as holding a position, in which not only the 
workmen themselves but the public also have confidence. The increased 
depths from which coal is now being brought, and in the future must still 
more be so, together with the large number of employes engaged in a 
mine, render it imperative that such works should be under the control of 
men of known ability. The distances which coal is now being brought 
to the shafts fix)m the faces of underground works is considerable and 
increasing (in some cases reaching three miles) rendering it absolutely 
necessary for the supervising engineer to have a knowledge of science 
as regards engineering and chemistry, which was unnecessary a few years 
ago ; and then only in a few cases would the possessor of this knowledge 
have had an opportunity of making it of any practical value. 

As an Institution comprising the mining engineers of this country it 
is our duty, and one I am sure we shall not shrink from, to point out the 
way not only by which their status should be improved, but also as a 
profession show ourselves equal to the task imposed upon us. 



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8 PRESIBSNTIAL ADDRESS. 

I may saj, without fear of contTadiction, that there is no profefsion 
upon which such a grave responsibility rests as ours, and of this we have 
daily experience. Not only are immense numbers of men working daily 
under the surface of the ground, each one of which carries a responsibility 
to us ; not only have we daily to lower them from the surface but also 
to' raise them, and this by means of machinery under the guidance of men 
who are not infallible. Surely that, gentlemen, is a position that we all 
appreciate to the utmost, and our great wish is to reduce so iar as we are 
able the loss of life that I am afraid I must say is almost inherent in 
mining. Much of late has been done to improve the ventilation of mines, 
and without entering into details, one may say it has been a great relief to 
many of us interested in the conduct of fiery mines, and if our Institution 
had only been the means of reducing the loss of life by explosions, 
we should not have federated in vain. 

We have much more than this, however, on our agenda-paper, and our 
duty lies in educating our profession so that not only do they fully 
recognize the sacredness of human life, but that the surroundings of the 
workmen also during the period of their employment should be such as to 
raise them as far as possible above the depressing influences that 
exhausting labour naturally brings with it. After every possible effort 
has been made in this direction, we then have to consider the reasons for 
which capital has been invested in the working of our mines ; and our 
object also should be to make a return to the investors equivalent to the 
risk for the capital expended. I maintain that the two principles run 
hand in hand, for I find in well-conducted mines, in mines which are 
being worked on carefully thought-out lines, that there also we find the 
investors have, as a rale, received the best interest on theii* outlay. 

Our Institution has a great future before it, and it only remains for 
those who are responsible for its conduct to guide it upon such lines as 
shall lead, not only its own members, but the mining industry as a whole, 
to look upon its teachings with respect. We must not keep altogethtJ 
to the beaten tracks, but move onwards, otherwise we shall be looked 
upon as a clog to the wheel, instead of what we should be, and have 
the power to be, the recognized leaders of those natural, scientific, and 
mechanical forces that may be brought to the assistance of mining 
engineering in every branch of its work. 



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DISCUSSION — PRESIDENTIAL ADDRESS. 9 

Mr. John Daolish (Newcastle-upon-Tyne) proposed a vote of thanks 
to the President for his excellent address, which contained matter of 
interest to all and would be of still greater interest when printed. He 
(Mr. DagUsh) hoped in the course of time that the whole of the mining 
and metallurgical institutes of Great Britain would federate with them ; he 
understood that there was a probability of the federative movement 
extending to the Colonial institutes. The mining industry was so great 
that it was possible there would ere long be a federation of all the mining 
institutions of the British Empire. If he might venture, not to take 
objection to anything contained in the address, but to make a remark 
thereon, he would like to refer to the question of examinations for mine 
managers. Having filled the office of examiner for twenty years he might 
naturally be expected to know something about it, and having retired from 
that position he had no further direct interest in it, but he should deprecate 
very greatly the introduction of any collegiate element into the examina- 
tions for mine managers. These examinations were for efficiency only, 
they were not to test the ultimate knowledge of a candidate, as with 
collegiate examinations, but for a certain amount of knowledge sufficient 
to entitle him to the management of colliery works, and especially in the 
practical department. He ventured to think that object could only be 
obtained by the examination of candidates t*iva voce by practical men. 

Mr. M. H. Mills expressed his pleasure in seconding the vote of 
thanks. 

The President acknowledged the vote. Far from joining issue with 
Mr. Daglish he would say that gentleman was quite correct. He was of 
the same opinion, namely, that no professor could examine in the details 
of mining, but he did think that the other subjects ought to come under 
the supervision of professors. He hoped, whether that was brought about 
or not, that the great object they all had in view — the raising of the 
standard of capacity of the persons who had the supervision of the mines 
of this country — would be attained. It mattered little in which way it 
was done, but it occurred to him that the examiners ought to be men 
.who had not only a thorough, practical but a scientific knowledge. 



Mr, JoBL Settle read the following paper on ** Spontaneous Com- 
bustion in Coal-mines " : — 



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10 SPONTANEOUS COMBUSTION IN COAL-MINES. 



SPONTANEOUS COMBUSTION IN COAL-MINES. 



By JOEL SETTLE. 



Introduction. 

Having experienced considerable difficulties in sealing off gob- fires at 
the Leycett collieries, the writer thought that a paper dealing with descrip- 
tions of some of these fires and the present mode of working would be of 
interest to the members of this Institution. 

The gob-fires which have been dealt with and illustrated in the follow- 
ing paper have occurred in the BuUhurst seam, at the Fair Lady pits, 
Leycett coDieries, North Staffordshire, the property of the Madeley Coal 
and Iron Company Limited. 

Gob-fires have occurred in almost every form of working which has 
been tried with the object of preventing them. Whenever a gob-fire 
commences the sooner the sealing-off is completed the better, in order to 
exclude the air from the goaf, to prevent it breaking into flame and 
igniting any accumulation of gas. As the BuUhurst seam gives little 
indication except the stink, which is very quickly followed by fire, and 
88 the seam gives off carburetted hydrogen freely, an explosion is likely 
to occur should the fire burst into flame. 

It must be understood that gob-fires can arise from a variety of causes : 
some have their origin in coal becoming crushed and powdered in breaks 
or cleats in pillars, subjected to great pressure.* 

Occasionally there are small pillars of coal which, in consequence of 
the thickness of the seam and the steep inclination, cannot possibly be 
got with safety and are left, becoming a source of danger, as they may 
heat. 

Occasional discharges of water from faults, etc., and moisture are 
conducive to the heating of the hussle or floor of the seam, consisting of 
a soft carbonaceous shale intermixed with streaks of coal and pyrites. 
That hussle, as well as coal, is Uable to spontaneous combustion is proved 
by several dirt-heaps which have fired on the surface. 

Fires of this description can be abated by a coating of sand 2 feet 
thick to exclude the air, but the fire still remains in a dormant condition, 

* The writer produced a ^mple of dust or small coal out of a break or cleat. 



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SPONTANEOUS COMBUSTION IN COAL-MINES. 11 

and should the sand be removed, the heat which the heap contains would 
by the admission of air again revive into fire and give off a very nauseous 
smell. 

Mines which give off carburetted hydrogen are exceedingly dangerous 
when gob-fires take place, and require constant attention. 

The thermometer should be constantly observed, but should not be 
relied upon, as gob-fires have frequently occurred without any perceptible 
change in temperature — ^suddenly bursting into fire. It is, however, very 
desirable that the temperature of the return air should be daily observed, 
and any increase must be taken as an indication that the goaf is heating. 

Generally speaking, the temperature of the Bullhurst return from the 
drift or goaf is 78 degs. Fahr. With one-half of the district heading* 
out and the other half drifting-back the main return is 74 degs. Faht. 
with little variation. 

The Bullhurst seam lies at a depth of about 500 yards, with a section 
consisting of : — 

Rock roof. Ft. In. Ft Iiu 
Bass 2 



Coal, Tops 

Middles .., 
Wall coal... 
Billies 

Hussle .. 
Ro«k floor. 



3 9 
8 
6 

2 

13 9 

..2 



The tops and billies are high-class steam coal ; the middles and wall coal 
a superior quality of gjis-coal and a very good house-coal; the slack 
produced, being of a bituminous nature, makes high-class furnace-coke. 

The levels are driven in the middles and wall coals, the tops and 
billies being got when drifting-back. 

The inclination of the Bullhurst seam is very irregular and contorted, 
varying from 15 to 70 degrees. The seam produces much fire-damp, and 
is very dry and dusty. There is practically no shot-firing, as the coals 
can be got without blasting. 

Top-RANGK Bang-up, North Side (Fig. 1, Plate I.). 

In deciding what distance to leave against a sealed-off goaf, the dip 
of the mine must be taken into consideration, as shown by the following 
case: — 

A very extensive fire, extending from A to B (Fig. 1, Plate I.), 
took place and was sealed off in October, 1888. Seven years after, a piece 
of coal was taken out below, leaving 50 yards of barrier between it and 



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12 SPONTANEOUS OOKBUSTION IN COAL-lflNSS. 

the old workings ; this was considered sufficient support, but proved to 
be inadequate. The angle of the seam being 55 degs., the coal slipped 
down until it thirled or communicated with the old workings lying above. 
A charred post which was found among the loose coals in the drift proved 
this conclusively. There was no indication of gas or gob stink, but the 
district was sealed off promptly by three permanent stoppings at C. 
Drifting was then recommenced with the customary temporary stoppings 
erected at D (which will be described later on). 

Gob stink was detected at E, and the district was sealed off on January 
18th, 1891, with stoppings at D, and further temporary stoppings were 
put ill at F ; it was most fortunate that this had been done, as an explosion 
occurred and blew out the stoppings at D five days afterwards. 

It was thought that the No. 8 or top stopping at had become un- 
capped, allowing the air to pass, resuscitating the old fire at A and igniting 
an accumulation of gas. Luckily no one was injured, the explosion having 
occurred on Saturday night, January 18th, 1891, and was discovered, 
during the Sunday morning's examination, by the damage it had done, 
and a strong smell of after-damp. Prompt action was taken and the 
sealing-off of the temporary stoppings farther back at F was completed 
by 2 p.m. of the same day. Tliis was not a moment too soon, as during 
the time of sealing off there were several suctions of air, indicating that 
slight explosions were occurring in the goaf, and showing that the fire was 
still supplied with sufficient air to maintain its combustion. These ex- 
plosions would no doubt in time have become larger and larger, and to 
prevent the air from going in to feed them required 80 yards of sand- 
packing along the three levels, all well pounded in, with brick-and-mortar 
stoppings intervening, as shown. Not only did the danger show itself in 
the workings at E, but the heat was revived at the point B, which is the 
main return airway, and extra strong work of brick-and-mortar was 
erected and the floor concreted. 

The temperature taken in a 2 inches pipe at B, 5 feet below the floor, 
in sand, remained at 125 degs. Fahr. for a very long time, and at 
present it is 102 degs., showing, when a fire takes place, that the goaf 
retains the heat, and should it be able to get a further supply of air it 
would be speedily revived. 

Top-range Bullhuest (Fig. 2, Plate I.). 

Fig. 2 shows workings in which the places were being worked in 
descending order. Upon several occasions small pillars of coal were found 
to be heating, and were loaded out as quickly as possible. 



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8P0NTANB0US COMBUSTION IN COAL-MINBS. 18 

On Noyember 80th, 1891, at 7 a.m., a haze or steam with a 
slight smell of gob stink was perceived in the working-places of this 
district at the point 6 coming off the goaf, and after careful examination 
it was decided to take out all materials at once and complete the temporary 
stoppings at the points marked 1, 2, and 8, the other four stoppings having 
been previously completed with permanent packing. 

We thought we were justified in making arrangements to draw out the 
materials, but were unable to do so. At 12 o'clock noon, a dense smoke 
appeared coming from the goaf, and the completion of the stoppings was 
pushed forward with all possible speed and completed by 8 p.m of the 
same day, bricks and mortar being in readiness at each stopping. These 
stoppings were not relied upon and were further strengthened with sand- 
and-dirt packing. 

It will be observed that there is a considerable distance from the goaf 
to where the temporary stoppings were erected, whereby much coal was lost; 
but in consequence of the angle of the seam being 55 degs. and the 
pillars being broken, there was no alternative but to erect the stoppings 
at the points 2 and 8, where the seam was practically level. 

Temporary stoppings had been erected for sealing off this district at 
the points marked H, and were never allowed under any circumstances to 
be disturbed until another course of temporary stoppings had been substi- 
tuted at a lower point. 

This is the largest area of BuUhurst coal that has been wrought 
before taking fire. 

BOTTOM-RANGB BULLHUEST (Pig. 8, Plate I.). 

Another principle of working the Bullhurst and other seams subject 
to spontaneous combustion was introduced some years ago by Mr. Prank 
Eigby at the Bunkers Hill collieries, which has proved very advantageous, 
and enabled them to be wrought with considerable success, and entire 
freedom from gob-fires up to the present time 

In this system the coal is wrought in descending order, and as each 
pillar of coal is worked out on the rise a stopping is put into the level to 
prevent the ventilation circulating through the goaf ; the next level below 
becomes then the return airway, and the goaf above becomes charged with 
gas, only allowing sufficient ventilation to pass to keep the edges of the 
goaf and working-places free from gas. 

Pig. 8 shows the district where this principle was first adopted at the 
liCyoett collieries; and as the drifts were finished permanent stoppings 
were put in, consisting of brick and mortar, and sand well packed. 



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14 SPONTANEOUS OOMBUSTION IN COAL-KINBS. 

It will be observed that the object of this system is to keep the yenti- 
lation o£f the goaf, by only allowing sufficient air to enter to ventilate the 
edges of the goaf and to keep the working-places free from gas, while the 
higher portion of the goaf is undoubtedly charged with gas. When it 
was safe to examine the internal parts of the goaf, gas was always found, 
but was not of an explosive character, about 3 per cent, being found on 
the edge of the goaf, showing that in this instance the principle worked 
very satisfactorily. 

The temperature at No. 6 stopping registered 84 d^. Fahr., which 
was always the temperature of the return from this goaf. 

The whole of the district was worked out successfully, and six stop- 
pings were completed, as shown in Fig. tS. The district appeared to have 
a little haze or steam on the return from the goaf on several occasions, 
and it was always concluded that if the internal part of the goaf had been 
ventilated it would have taken fire. 

Turning to another portion of Bottom-range Bullhurst, where only two 
drifts had been worked back, and the place, on account of the inclination of 
the seam running irregular (Fig. 4, Plate I.), had caused some little water 
to accumulate, which was pumped out. In a very short time (on Novem- 
ber 12th, 1892) a peculiar gas, without gob stink, was observed to be 
given off, and stoppings were put in, treating it as a gob-fire. This gas 
was constantly given off without gob stink, and, so long as it continued, 
the strengthening of the stoppings by dirt packs was extended. The 
stoppings then appeared to have almost stopped the gas from coming off. 

At 7'BO a.m. on December 13th, 1892, a great rush of wind occurred 
in the district, which was observed at the bottom of the downcast shaft, 
some 900 yards distant. 

An examination showed that there had been an explosion in the 
internal part of the old workings where the gas had been given off, and 
smoke was found issuing freely from the drifts. There was no smell of 
after-damp, but a slight smell of gob stink, and the gas given off was of a 
heavy nature, no doubt deadened by the smoke emitted, and about 3 per 
cent, of gas was indicated; upon the Mueseler lamp. 

The customary precautions had been taken by erecting temporary brick- 
and-mortar stoppings at the entrance to the district ; and sufficient bricks 
were at hand, only requiring mortar to seal off the same in case of emer- 
gency, so that the district was closed by 12 o'clock noon of the same day. 

From time to time since it was sealed off this work has given a con- 
siderable amount of trouble. It has always been the writer's ezperienoe 



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8P0NTANB0US COMBUSTION IN COAL-MINES. 16 

that whenever a district gets on fire there is a very great tendency to draw 
in air, and extraordinary lengths of packing are required to prevent it ; 
but if the district can be sealed off before it breaks into flapie short 
lengths of packing will suffice. 

Bang-up Bullhubst, South Side (Fig. 5, Plate II.). 

The principle of working with the goaf charged with gas in the 
Bottom-range BuUhurst having proved successful, enabling the whole of 
the district to be worked out, it was decided to apply the principle to 
another district called Bang-up BuUhurst. 

When the coal was got above the No. 5 level the first stopping was put 
in at No. 5, bringing the return air through No. 4 level. This stopping 
is 22 yards in length of sand, pounded in on the level with two brick-and- 
mortar stoppings of three feet thick. 

As the district gave off a large quantity of gas the goaf was rapidly 
chai^ged, and even with all this length of packing gas was emitted very 
freely from No. 6, the top stopping ; the temperature of which was 84 
degs. Fahr. for a considerable time. 

When the drifts were worked out lower No. 4 stopping was inserted, 
consisting of two brick-and-mortar stoppings and 22 yards of sjmd-pack- 
ing. No. 3 level now being the return, and the temperature 78 degs., 
which increased in about two months to 84 degs., and when the district 
was sealed off it was 86 degs. Fahr. 

Temporary stoppings were put in at Nos. 1, 2, and 8 levels, consisting 
of 8 feet of brick and mortar with tub roads through them, and in all 
cases sufficient bricks were left at each stopping to close the district off 
promptly in case of emergency, all that remained to be done being to get 
mortar to each stopping, and build up the openings or tub roads. 

It was calculated that it would take four hours at the outside to seal 
off the district, strengthening the same afterwards by more permanent 
work of lengthened sand-packing, etc. 

The district had been worked out to the position shown, when it gave 
rise to great anxiety and careful watching, the temperature rising to 88 
d^. at No. 5 in front of the stopping and 96 degs. against the coal. 
No. 4 also began to give off gas, the temperature being 84 degs: Fahr. 

The gas at No. 5 stopping had a peculiar odour, and was very explo- 
sive. About 8,000 cubic feet of air per minute was passing this stopping. 

A Uttle haze appeared upon the ventilation at I, and as this had 
hitherto been an indication of gob-fire, the district was sealed off without 
delay. 



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16 SPONTAKEOUB COMBUSTION IN COAL-MfNBS. 

The temperatare at No. 5 stopping increaBed, commencing at 78 d^a. 
and terminating at 88 degs. againat the pack and 96 degs. against the 
coal on the head aide of the level. The day after the district was sealed 
off the temperature at No. 5 stopping registered 80 degs., gradnallj falling 
within one week to 76 degs., and it hus remained at the same temperature 
ever since. 

Althongh the district was sealed off on December 28th, 1892, No. 5 
stopping gives off gas freely to this day, Nos. 1 and 4 slightly, while Nos. 
2 and 8 do not give off any gas. 

It will be gathered from these remarks that Bang-up Bullhurst varied 
from the working of Bottom-range Bullhurst. When worked upon the 
same principle it caused great anxiety, in consequence of the large quantity 
of gas given off from the stoppings and the temperature reaching 96 degs., 
whereas the district (Pig. 3) worked on the same principle gave off very 
little gas, and the temperature remained constant at 84 degs. 

Outside this district (Fig. 5) drifting was again commenced, and after 
some little time the hussle or floor was found to have heated very much, 
and would speedily have been on fire. Oreat difficulty was experienced 
in clearing it out, as the heat had risen from the hussle into the pillar of 
coal. This heat arose in a piece of troubled ground which might be 
termed more accurately a roll of dirt than a fault. 

The writer mentions this circumstance because the origin of this heat- 
ing was clearly traceable to the hussle or floor. 

Gbnbbal Conclusions. 

The greater the number of stoppings to be completed when a gob-fire 
takes place the greater will be the risk, as every delay adds to the danger 
and cost. The adoption of temporary stoppings will be found of the greatest 
possible advantage and to afford great additional security. 

There should not be more than three openings to seal off. It is even 
better if only two can be arranged, that is, an intake and a return only. 

The temporary arrangements which the writer recommends for work- 
ing the Bullhurst seam are, to put in 3 feet of brick-and-mortar stoppings 
cut to a solid bed all round, that is passing all breaks in the coal and 
surrounding strata. Sufficient openings are left in the stoppings for the 
horse and journey to pass through. A sufficient number of bricks should 
be placed, close at hand, to complete the stoppings in case any symptoms 
of gob-fire are discovered. The only material required will be mortar, and 
in case of emergency such stoppings can be completed in three or four 
hours at the very most. 



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SPONTAKBOUS COMBUSTION IN COAL-MINES. 17 

Brick-and-mortar stoppings must only be considered as temporary, and 
after the withdrawal of the men and allowing safiScient time to elapse 
(that is in case the gob-fire has shown serions symptoms) before an 
examination is made, so that the internal part of the workings sealed-o£f 
may become so charged with gas that there would have been an explosion 
if such danger existed. The result of the examination of the stoppings 
will be a guide as to what course is next to be adopted ; generally, it will 
be found that explosive gas is being given off at the highest stopping, the 
lower or bottom one at the same time taking in air, to prevent which the 
defective parts should be plastered with mortar at the time of inspection. 

After this examination it may be advisable to allow a further time to 
elapse before commencing to pack with sand or small dirt against the brick- 
and-mortar stoppings, but this should not be pressed forward too hastily, 
as the packing will sink, no matter however well pounded in. These 
temporary arrangements will be less costly if they are carried out, and 
the materials conveyed to the places determined upon, during working 
hours. 

It is not advisable to have less than 30 yards in length of packing 
against the temporary stopping along the level of a sealed-o£f district, to 
prevent the fire from sucking in air, and to complete the end of such pack 
by a brick-and-mortar stopping not less than 2 feet thick, and plastered 
over with mortar to make any weakness more perceptible. This work may 
seem to be extraordinarily strong, but it will be required to prevent the 
goaf sealed-off from being disturbed when drifting is again commenced. 

As the Bullhurst seam m of great thickness (13 feet 9 inches) it is 
surprising what large falls take place when drifting or bringing back 
pillars, and there might be breaks in the roof which would allow gas to 
escape from the internal goaf sealed-off. If that should be the case, the 
same goaf would take in air and give off gas alternately at one and the 
same point, that is, making an intake and return of the same place, 
causing danger to arise unawares. 

With a view of leaving as little coal as possible, drifting is sometimes 
commenced in too close proximity to the sealed-oflf goaf, thereby disturb- 
ing or uncapping the old stoppings and reviving the old gob-fire. It is 
probable that more accidents arise from this cause than any other. 

Pig. 6, Plate II., illustrates a method of economically and success- 
fully working the Bullhurst seam in panels on the pillar-and-stall principle 
by which only two stoppings are required to seal oflf the district, and a new 
district may be headed out ready for drifting when the one adjoining is 
finishing. 

VOL. v.-ww-w. 2 



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18 DISCUSSION — SPONTANEOUS COMBUSTION IN OOAL-MINBS. 

Fig. 7, Plate II., illustrates a method of working seams on the long- 
wall principle, but it is not applicable to the Bullhuist seam, on account 
of its thickness, inclination, etc. 

The principle recommended for working a mine subject to spontaneous 
combustion with safety is not to open out too large an area of coal in one 
district, so as to enable the same to be worked and sealed-off before it 
even gives indication of gob-stink ; it also gives further advantages, as the 
workings can approach closer to sealed-off districts with greater safety if 
they have not taken fire, and the loss of coal will be considerably less. 

Levels should be driven to the boundary, and the panels worked back 
in all cases, so as to leave the sealed-off goaves behind. 

A piece of coal 100 yards on the level by 80 yards on the rise is pro- 
bably the safest and most convenient size for working in thick seams of 
steep inclination, subject to spontaneous combustion. 

In thin seams a larger area of coal might be determined upon according 
to circumstances. 

The following fundamental principles should be observed : — 
(fl) Do not try to work out too large a district at once. 
(6) Districts should be worked out as quickly as possible, and sealed 
off when finished, whether they have taken fire or not. 

(c) Leave sufficient support of coal so as not to disturb sealed-off 

districts. 

(d) Preparatory or temporary stoppings should always be erected. 

(e) The quality of gas given off from a goaf should be carefully 

noticed. 
(/) Note any change in temperature from the goaves. 
Of) Do not pass more ventilation through a district than is sufficient 
to keep the working-places and gob-edges free from gas. 
The writer particularly desires to mention that Mr. Atkinson, H.M. 
Inspector of Mines, has taken great interest in the working of this mine, 
and has seen all the districts referred to. 



Mr. E. B. Wain (Stoke-upon-Trent) wrote that the special point in 
this paper was the exceptional circumstances described under which the 
gob-fires had been dealt with. The paper was especially interesting as 
following that on the same subject read at the last Federated Meeting,* 
in which Prof. Lupton gave a general description of the manner of 
occurrence and methods of dealing with fires under what may be termed 

* TraTU. Fed. Inst., vol. iv., page 481. 



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DISCUSSIOir — SPONTAKBOUS OOMBTTSTION IN COAL-MINBP. 19 

ordinary circnmstances, in Derbyshire, Leicestershire, and Warwickshire, 
where the easy gradients and small volumes of fire-damp rendered the opera- 
tions, in dealing with such outbreaks, comparatively simple. Mr. Settle, 
however, takes up the question of dealing with fires which have occurred 
under most exceptional circumstances, where the heavy gradients (up 
to 70 degrees), the fiery nature of the seams, and the thickness of the coal 
rendered the operations much more difficult; and the greatest possible 
credit is due to Mr. Settle for the thorough manner in which he had 
dealt with the outbreaks he had, from time to time, had to contend with 
at the Leycett collieries. Notwithstanding the exceptional difficulties 
under which the work had been done, it had been carried out in such a 
manner as to reduce the danger to a minimum ; and although, some years 
ago, before Mr. Settle had charge of the colliery in question, serious loss 
of life had resulted from explosions arising from gob-fires, the methods 
which he had originated and carried out had proved to be thoroughly 
successful in preventing similar disasters. In considering the subject, 
however, it is impossible not to feel regret that it should be necessary to 
sacrifice so large a quantity of most valuable coal in pillars and barriers, 
in districts closed from fire, as a safeguard for future workings ; and one 
was led to ask the question, whether some means could not be devised by 
which such loss might be avoided ? The system which had been adopted 
at some of the collieries in the Warwickshire district, and which was 
briefly mentioned in Mr. Lupton's paper,* appeared to be particularly 
applicable to such circumstances as those which the paper under consider- 
ation referred to. If a number of dip headings were driven down to the 
deep boundary, and so arranged that one engine might draw out of several 
of them, and the coal was worked out with a longwall face advancing 
from dip to rise, any water there might be in the mine would fill up the 
workings as the face advanced and effectually prevent any spontaneous 
combustion in the goaf. Even if there were no water in the workings, 
they could easily be flooded if any danger from fire was apprehended, 
without in any way interfering with the progress of the coal-getting. 
Another distinct advantage of such a system would be the absolute avoid- 
ance of any danger arising from fire-damp, as the numerous dip headings 
from which the coal was drawn would effectually drain any gas produced 
at the working-face* At first sight it would appear, from the numerous 
engine-brows, that the hauling arrangements would be unnecessarily 
complicated, but this would not be so. The writer has seen, in the 
Nottinghamshire coal-field, somewhat simUar arrangements working very 

• Trans, Fed, Inst., vol. iv., page 484. 



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20 DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 

satisfactorily : the only difference being that, instead of the face advancing 
from dip to rise as proposed, and the coal being drawn through the solid 
roads, the workings were advancing with a dipping face and packed roads. 
An engine-brow was taken down the centre of the work with cross-gates 
driven from it at an angle of 45 degrees, and branch-gates parallel to the 
centre gate-road turned off the cross-gates at suitable intervals. By this 
arrangement the trams were worked to and from the actual coal-face by the 
plane-rope, and one engine and rope served twelve or more stalls. In the 
plan proposed for working up-bank through solid roads similar arrange- 
ments might be used, or the main-plane and cross-gates could be worked 
by an endless-rope, and drums driven by friction-gear from a belt-rope 
used to draw single tubs up the branch roads to supply the main-rope. 
The plan had many features to conmiend itself ; absolute freedom from 
gob-fires, no danger from fire-damp, and the cost of hauling and main- 
taining the roads reduced to a minimiim. The only apparent drawback 
was the large initial expense in driving out dip headings to the boundary, 
but this would be more than repaid by the reduced cost of working, and 
the greater safety ensured. 

Mr. Samuel Spruce (Tamworth) wrote : — As one would expect from 
the author, this paper was highly interesting and instructive, as showing 
the methods adopted to get quit of the gob-fire in the Bullhurst seam at 
Leycett colliery. There were, no doubt, peculiarities attaching to this 
colliery, in the thickness of the Bullhurst seam and the high pitch of the 
mines : one perhaps was the very wide rib which appeared to have been 
rendered necessary on account of the angle of the seam being as high as 
55 degrees. He (Mr. Spruce) did not know an instance where so large a rib 
had been permanently left on account of gob-fire ; but he had known 
cases in which a whole district required to be dammed off— because the 
excessive heat prevented a nearer approach to the part on fire — and left 
for a year or two, or even more, before again approaching it ; and 
possibly had the same plan been practicable in this case, and the district 
remained closed a sufficient length of time, a rib of less width might have 
sufficed ultimately. Apart from this question, however, there were some 
points in common, as regards gob-fires, with other seams in other parts 
of North Staffordshire and other places; he was, generally speaking, in 
agreement with the author of the paper, though in some respects he 
differed slightly. The methods adopted with regard to the stoppings 
at Leycett colliery appeared, so far as he understood them, similar to 
those adopted and used in nearly all kinds of seams, thick and thin, both 
in Shropshire, Staffordshire (North and South), Worcestershire, and 



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DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINBS. 21 

WarwickBhire, to hia knowledge during the past fifty years and more, 
where gob-fires have occurred ; except that he had never known it neces- 
sary to put in the great length of stopping mentioned in the paper of 
" 30 yards of sand-packing along the three levels, all well pounded in, with 
brick-and-mortar stoppings intervening, as shown." He would like to know 
whether this was not an extremely exceptional case, even in these steep 
mines ? and he would like to learn also what kind of strata there were above 
the coal, to the extent of about three times the thickness of the seam ? 
He noticed it particularly as being " on the level," as this would appear to 
assume that an unusually thick rib, from dip to rise, was also necessary to 
support these 30 yards of stoppings, at least as wide as the length of 
the stoppings themselves; and also whether, in the experience of the 
author, a 50 yards rib was necessary if the panels were worked in 
ascending order ? He entirely agreed with Mr. Settle that " whenever 
a gob-fire commences the sooner the sealing-oflF is completed the 
better." He (Mr. Spruce) affirmed in his paper on "Pit Fires," 
read before the members of the North Staffordshire Institute of Mining 
and Mechanical Engineers, in June, 1885,* that beyond a certain limit 
"atmospheric air is the greatest promoter of gob-fire which can be 
found," and that it is necessary "in the first place as early as con- 
venient " to " exclude from the gob-heaps atmospheric air entirely ; " but 
he also expressly pointed out at the same time that this was a totally 
different thing from crippling or even reducing the general ventilation 
of the working-places of the mine, with which some people appear to 
confound it. He did not know whether the writer of the paper had been 
moved to some of his remarks in consequence of what was said at the 
Derby meeting, where the notion appeai*ed again to crop up that ventilation 
would cure gob-fires ; but his observations came in very appropriately. He 
(Mr. Spruce) had no doubt that the writer did not put in any of the dams 
referred to in the paper, with the object of turning a current of air upon 
the gob-fire with the view of curing it. Was it not somewhat singular 
that however often this notion of curing gob-fire by ventilation might 
come to the front, as it had done from time to time for many years past, 
it was advanced only as a speculative proposal, and never, so far as he 
was aware, had it been accompanied by proof from actual experiment that 
any extensive gob-fire had really been subdued by that method. Nor was 
it at all made clear by any well-authenticated case that increased ventila- 
tion had ever prevented, or even retarded, a real gob-fire of any important 
dimensions. A small fire, such as could be loaded out, might be got rid 
• Trans. A'orth Staff, Inst,, vol. viii., page 38. 



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22 DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 

of by being brought into the open, where it would either be extinguished 
from separation or burn itself out. He had known instances in which 
heating gob, or rather the slack improperly left as gob, taken out before 
it had actually caught fire, had (on being loaded out) broken into flame 
on its passage to the surface. He (Mr. Spruce) had known actual fire 
prevented in the Thick Coal seam, when imminent, by temporarily 
cutting off the ventilation, from the side of work or panel in which it 
occurred, for three nights and two days, generally at the end of each week 
for several weeks, until the extensively worked side was entirely cleared 
out in safety and with comparative comfort on the remaining days, guided 
by the sense of smell on the part of the manager, or someone else who 
had that sense sufficiently developed, and in whom reliance could be 
placed as to when to work and when to cease working. This fact related 
to a side nearing its completion, but he had also known, in the Thick Coal 
seam, the same thing to occur on a very much larger scale, in which a large 
side of work had indicated imminent gob-fire — known by the same means 
as well as by the increasing temperature of the heating slack ; and here 
it was well known there was nothing else but the slack left therein that 
could fire, there being an underclay floor, no parting in the coal saving 
7 inches of sandstone known as " hard stone," the upper coal still hang- 
ing, therefore no roof had fallen, and the loose wrought coals being all 
drawn out. The side of work, being as designed, 70 yards by 90 yards 
in about mid-working, was closely sealed up, and kept so for a period of 
three months, and then again opened, when all apprehension of fire and 
gob-stink was entirely gone, and the work resumed as usual and carried 
to a successful end. But such a result as this must not be looked for 
if the gob had passed the stage of " fire-stink," and actual fire had once 
got a good hold of the slack. He (Mr. Spruce) had known seven years 
of close sealing insufficient to be quit of this, that is to say, it would 
quickly revive into active fire on the re-admittance of atmospheric air. 
Of all the ineffective measures for dealing with real gob-fires, or gobs 
readily given to fire, that of using clay in " wax walls," as it is called, was 
— speaking always within his (Mr. Spruce's) experience — the worst. He 
thought it ought rather to be regarded as a fire-promoter than a fire- 
preventer ; at any rate any gob that would do with it would do equally 
well without it. Just thirty-five years ago he became acquainted with this 
process in a Warwickshire colliery, in the Seven Feet and Deep Coal seams 
worked by longwall, where the fires in each seam were so extensive under 
this system that the colliery — while not half worked out — was on the 
point of abandonment af fer nearly ruining its ownera, who offered, and 



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DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 23 

were only too glad, to part with it and all the plant— raising over 2,000 
tons weekly — for an insignificant sum. A gentleman, well versed in 
colliery working, and who had had large experience in gob-fires, and 
knew generally how to deal with them, was ready enough, indeed was 
anxions, to embrace the offer and to purchase. But he hesitated to do so on 
account of these tantalizing and ruinous fires, of which it is not too much 
to say that for hundreds of yards along the return air-courses and some 
gateways livid fire was at intervals visible, only kept in partial abeyance 
by this clay-dabbing, on which from 17 to 25 men and boys had for a 
long period been constantly engaged in daily and nightly work called 
" waxing the carvings." It was only by the strongest assurances that the 
whole system could be changed in a month or so without further danger 
and at little expense, that he did ultimately purchase. The system was 
accordingly changed, but still working longwall, and from that day to 
this — ^f or the colliery was still going, and would continue for many years — 
not a pound of clay had been used for that purpose, nor had there been 
any bat the most insignificant of gob-fires, only just sufficient to show 
that such fires would still prevail if permitted. Here and elsewhere there 
were thousands of yards of gob-roads ; one pit in one seam had now over 
3 miles of gob-roads open, and no clay had ever been used or needed, and 
never would be. He (Mr. Spruce) thought there would never be found in 
any seam worked by longwall any gob-fire (using this term in the proper 
sense), so long as not less than 1,400 tons of coal for every statute acre 
for each foot of thickness of the entire seam was extracted and sent out 
of the mine. 

Mr. 0. J. BiNNS (Netherseal) asked whether bituminous or non- 
bituminous coals were the more active in causing spontaneous combustion ? 
It seemed to those managing mines in which spontaneous combustion 
was rife, and in which gas was infrequent, to be a dangerous state of 
things to have so much gas ; he supposed, however, that in the district 
Mr. Settle represented they were used to it. He had found that clay 
stoppings — though not in the form of wax walls — in place of brick stop- 
pings gave way without breaking under pressure, which rendered the 
brick stoppings useless. 

Mr. W. N. Atkinson (H.M. Inspector of Mines, Newcastle-under- 
Lyme) said the spontaneous combustion of coal in mines was of special 
interest in North Staffordshire, because in that coal-field such combustion 
frequently occurred in seams producing much fire-damp and very dusty ; 
so that in addition to danger from the fire itself there was risk of serious 
explosions. The BuUhurst seam at Leycett colliery, in which the gob-fires 



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24 DISCUSSION — ^SPONTANEOUS COMBUSTION IN COAL-MINES. 

described by Mr. Settle took place, was both gassy and dusty, and its 
liability to spontaneous combustion was therefore a source of great anxiety, 
and the successful way in which Mr. Settle had dealt with a number of 
gob-fires had only been accomplished by very great vigilance and care. 
Spontaneous combustion in mines was until recently most frequently 
attributed to the presence of iron pyrites in the coal, but it was now 
understood to be due to the oxidation of the coal itself, or of carbonaceous 
matter associated with coal, and the presence of iron pyrites might be 
favourable to spontaneous combustion, but it was not a necessary element. 
There are, however, no means, except experience, of telling whether any par- 
ticular seam of coal would be liable to gob-fires, nor why some seams were 
extremely liable to gob-fires, others slightly so, and others not at all. In 
North Staffordshire spontaneous combustion occurred under varying condi- 
tions. The great majority of fires began in the gob, but cases were known 
where they had broken out on roads or in pillars of coal. They gave 
warning of their presence first by the characteristic gob-stink, and then by 
emitting vapour and smoke ; but in some cases these warnings were so 
slight, or of such short duration, that they were not observed until the 
combustion has arrived at the stage of actual fire. In other cases 
indications of incipient combustion were observed for several days or 
weeks before there was red heat or fiame, and sometimes the heating 
abated without reaching the stage of incandescence. Certain conditions 
were generally held to be conducive to gob-fires in seams liable to spon- 
taneous combustion. One of these was the presence of coal in the gob ; 
this should be avoided as much as possible, but it was often impractic- 
able to get the whole of the coal or to prevent coal being left in the gob. 
Impure, disturbed, or faulted coal in some seams was supposed to be 
peculiarly liable to spontaneous combustion. Water or moisture was some- 
times held to be an exciting cause. One gob-fire, which came under his 
(Mr. Atkinson's) notice, occurred a few months after the use of water was 
adopted in the district for damping dust, so that gunpowder shots might 
be fired, but several gob-fires occuiTed in the same seam at a neighbour- 
ing colliery without such an exciting cause. It was sometimes supposed 
that pressure or friction caused spontaneous combustion in mines ; beyond 
that by crushing and pulverizing, the coal was rendered more liable to 
spontaneous combustion from other causes, he failed to see that pressure 
or friction had any effect. There appeared to be some difference of 
opinion with regard to the effect of ventilation on gob-fires. Some 
engineers were in favour of strong ventilation and others advocated as 
feeble a ventilation as practicable. By acting as a cooling agent, venti- 



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DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 25 

latioD might prevent spontaneous combustion, but the majority of gob-fires 
occurred in inaccessible situations where the ventilation, however strong, 
could not act as a cooling agent, and the stronger the ventilation the more 
difficult it was to prevent feeble currents passing through the gob, and this 
appeared to be one of the most common exciting causes of gob-fires. He 
might mention the case of a colliery where the Bullhurst seam was worked 
for several years with a comparatively feeble ventilation without any 
gob-fires occurring ; a large fan was then erected at the downcast shaft, 
which was made the upcast. For some months the fan ran at a reduced 
rate owing to its shaft heating, but nine months after it started, the first 
gob-fire was discovered in the pit and there had since been several serious 
gob-fires. The debriB round the top of the shaft and fan-drift also took 
fire, probably owing to air being drawn through it into the shaft and fan- 
drift, the brickwork of which was not airtight. The Royal Commission 
on Spontaneous Combustion of Coal in Ships condemned the attempts 
which had been made to ventilate the bulk of the cargo, alleging that 
such ventilation as could be applied for that purpose was conducive to 
spontaneous combustion, no doubt for the same reason that slight currents 
of air passing through a goaf were favourable to gob-fires. The idea of 
excluding air from the goaf was the basis of the system practised by 
Mr. Rigby, at Bunker's Hill colliery. When^the goaf was to the rise it was 
allowed to fill with gas, and when it was to the dip it could be filled with 
water. It might appear objectionable purposely to allow a goaf to become 
charged with fire-damp, but if it prevented gob-fires it would be more of a 
safeguard than a danger, and it must be remembered that it was often 
impossible to prevent a goaf becoming charged with gas. By adequate 
ventilation the working-places ;might be kept free from gas, and if shot- 
firing was not allowed the risk was reduced to a minimum. In the case of 
the Bang-up Bullhurst, south side, at Leycett collieries, the system was 
a partial failure, as indicated by the temperature of 96 degs. Fahr. ob- 
served at No. 5 stopping, but in this case it was possible that the heating 
had begun before the air was prevented from passing through the goaf. 
The usual method of dealing with gob-fires in North Staffordshire was to 
isolate the places where they occurred by airtight stoppings. It was seldom 
possible to dig the fire out, and except in rare cases it would be dangerous 
to try to do so. The stoppings should be made as tight as possible, and 
afterwards strengthened by stowing, so as to resist an internal explosion 
should such occur. The preparatory stoppings described by Mr. Settle 
and the restriction of the number of openings required to be stopped were 
of the greatest assistance in dealing with a gob-fire. 



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26 DISCUSSION— SPONTANEOUS COMBUSTION IN COAL-MINBS. 

Sir George Elliot, Bart., said the subject was a very interesting one, 
and perhaps they could discuss nothing with more advantage to the 
Institution or mining engineering practice generally. He had been 
connected with coal-mining in the particular district referred to, for the 
past thirty years at Harecastle colliery, drawing perhaps 1,600 tons per 
day, and they had had many gob-fires ; the coal lay at various angles and 
the BuUhurst seam varied from 5 to 14 feet in thickness. Gob-fires were 
a great expense, and a great nuisance ; but mining engineers got into the 
way of trying to understand them as time went on, and he was glad to say 
they had not suflFered very much recently, owing to clear and distinct atten- 
tion being given to the early symptoms which arose by smoke and smell — 
which should be dealt with promptly. The system they had practised for the 
past twenty years had been the entire exclusion of the atmosphere : his long 
experience and great practice had led him to direct this to be done with the 
assistance of the very competent engineers he had under him (Mr. Craig, 
Mr. McGowan, and other clever men), and he thought it would be right for 
him to state that he thought Mr. Settle had done well to bring this subject 
before the Institution. At the present time he was rather largely concerned 
in an extensive colliery near Halifax in Nova Scotia. The manager 
came from North Staffordshire, the mine was on fire from spontaneous 
combustion, and he would be very well satisfied if the cost of the difficulty 
did not exceed £40,000 or £50,000. He supposed the fire would be 
mastered eventually, the difficulty was that, when it was believed to have 
been overcome, the atmospheric air seemed to be let in too early and fired 
the whole place again. He would impress upon all concerned in like 
difficulty, to deal with the matter promptly and to exclude the air as effect- 
ually as possible. The remedy which had been suggested of taking out 
1,400 tons of coal from every foot thick per acre would, he thought, be a 
good one, for if they could work this quantity he thought there would be 
none left, but he had known spontaneous combustion to occur where 
practically no coal had been left. In the Harecastle district there was an 
oil-shale in the vicinity of the BuUhurst seam, and he had known fires 
started by spontaneous combustion after the coal had befen removed. The 
evil they had to deal with was the constant lighting up, and, he believed, 
the sovereign remedy was careful watching, and to work their districts, 
if possible, in panels so as not to have too large an area exposed. 

Mr. G. E. Coke said he had lately had the opportunity of tracing the 
source of an underground fire in a rather unusual way. In a colliery with 
which he was connected, the deputy, in his morning inspection, found 
smoke coming out of the returns, and on following it to its source he 



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DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 27 

foand that a shot had been fired the previous night, and the dust had 
taken fire and been burning all night. When the deputy got to the place 
he found that the coal was incandescent, and if this discovery had been 
delayed, the consequences would have been most serious. This might 
afterwards have been put down as a gob-fire, and he mentioned the case 
with the view of asking whether it were not likely that other supposed 
gob-fires might sometimes be traced to similar causes ? 

Mr. T. A. Southern (Derby) supposed Mr. Coke did not infer that 
all gob-fires were due to such causes. 

The President mentioned that he had had a precisely similar experi- 
ence in South Wales. 

Mr. 6. E. Coke said he had only mentioned the case as showing the 
importance of being able to trace the source of fire. 

Mr. H. W. Hughes (Dudley) said he did not wish to say anything at 
length on this subject now, as the South Staffordshire Institute had 
arranged to start a special discussion on the subject, and he had written 
an introductory paper dealing with the various theories to which spon- 
taneous combustion was supposed to be due. However, he would like 
briefly to confirm Mr. Settle's final conclusions, and to say that, broadly 
speaking, the majority of them were supported by the experience they 
had gained in working the Ten Yards coal in the South Staffordshire 
district. There was no question in South Staffordshire as regards a and ft, 
that they were proper precautions, and especially that which recommended 
the districts being sealed when finished. He agreed that sufficient coal 
support should be left ; but he also agreed with Mr. Spruce that it had 
never been found necessary to leave ribs so strong as 50 yards wide. He 
considered the case Mr. Settle cited to be an exceedingly exceptional one, 
the seam being practically vertical, with the result that the weight and 
cracks might pass over the barrier and affect workings very much farther 
to the dip than if the seam had been only slightly inclined. He thought 
everyone who had actually worked Thick Coal admitted that up to a 
certain point the more air they could get into the workings the better. 
Mr. Spruce was an old South Staffordshire mining engineer, and therefore 
he was surprised at that gentleman expressing a contrary opinion. No one, 
of course, would be so foolish as to say that the best way to put out a 
gob-fire was to put on more air. It might be true in a literal sense that 
ventilating a gob would prevent fire, but he supposed it was practically 
impossible to ventilate any gob, as they could not get in enough air to 
cool it. They could supply sufficient oxygen to assist the oxidization of 
the organic constituents of the coal, but not enough air to cool down the 



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28 DISCUSSION — SPONTANEOUS COMBUSTION IN COAL-MINES. 

heating. Mining engineers, in speaking of " solid coal," broadly applied 
the term to any coal which was not in process of working ; consequently, 
pillars of 50 or 60 yards square were spoken of as solid coal. Such pillars 
did fire, and there were many instances of such occurrences ; but at the 
same time, when they did fire fissures were always found. He did not 
think there was any question, so far as their practice went, that, supposing 
it possible to introduce enough air, if they did so they would probably put 
out the fire. There were no instances on record of coal ever having fired 
in the solid, literally so called ; of course he spoke in a literal sense, and 
by "solid" he meant to say coal which was not cracked. Mr. Binns 
asked for information as to whether a highly bituminous coal was more 
likely to fire, or whether steam-coal and coal of that class was more 
subject to outbursts. From his own experience he could not say, but, 
with the exception of one author, every one who had written on the 
subject from the time of Dr. Percy (thirty years ago) to the present day, 
considered that coals which contained a large quantity of oxygen were most 
liable to spontaneous combustion. Of all the known coal-seams those 
most liable to spontaneous combustion contained a large quantity of 
bituminous matter; coking-coals were more free, if not entirely free, 
from such action ; and there was no instance on record of an anthracite- 
mine ever taking fire spontaneously. 

The President said that Mr. Settle had given in his paper actual 
cases of gob-fires, and detailed how he had dealt with them, which was 
an advance in the right direction. He was personally in agreement with 
Mr. Settlers views, and he thought no man would take a large volume of 
air and force it into such workings as described in the paper. He had 
seen mines which, under natural circumstances, were very hot, and, when 
cooled down by ventilation, the danger would pass away, whereas in other 
collieries a large volume of air would quickly cause a serious underground 
fire. He was sorry that Mr. Spruce was not present to-day to follow up 
the remarks which the Secretary had read respecting wax walls. He 
had worked out large districts of coal, subject to spontaneous combustion, 
by using wax walls ; but their value depended entirely on how tliey were 
applied. He did not quite follow Mr. Spruce in his remark as to 
taking out 1,400 tons to the foot per acre reducing the liability to fire. 
He might mean, as they had already been told, that they were to take 
out all the coal, and so leave no liability to spontaneous combustion ; but 
this did not agree with his (the President's) experience, for combustion 
was not always due to small coal being left in the mine. One could 
not help thinking that the only proper way to work a seam which was 



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DISCUSSION — SPOirrANBOUS COMBUSTION IN OOAL-MINBS. 29 

liable to spontaneous combustion was to work it so that should a fire 
arise they were in a position to dam off any affected district. Engineers 
were not immaculate, and could not possibly look after every detail 
which might be considered necessary in the workings of a mine liable 
to spontaneous combustion ; but he could not too highly endorse Mr. 
Settlers recommendation not to try to work too large a district at once. 
Mr. Settle had placed facts before them in a way in which they had not 
been presented to them previouslyy and he suggested that the paper should 
be referred to the local Institutes for further discussion. 

Mr. T. B. FoBSTER (Newcastle-upon-Tyne) asked Mr. Settle to give 
a section of the rock-roof above the seam of coal, whether any seams of 
coal lay immediately above it, what amount of coal was extracted, was 
the whole of the coal filled, or was the small coal cast back into the gob, 
and what amount of coal was lost ? 

Mr. M. H. Mills (Nottingham) asked if there had been any serious 
endeavour to work out the entire seam ? 

Mr. Joel Settle, replying to the discussion, said that in working the 
BuUhurst seam at Leycett collieries they had no other course but to work 
out small districts. Mr. E. B. Wain suggested that the winnings might 
be driven to the dip and the coal worked upwards, filling the gob with 
water. The suggestion was a good one, but could not be applied to the 
cases described in his paper, as the mine was so irregular in its inclination 
that it would be impossible to make one main engine-dip. Mr. Spruce 
had taken exception to 50 yards of barrier-coal being left to support the 
sealed-off goaf. He should take into consideration that the angle where 
the coal was left was 55 degs., and they had absolute proof on the table 
before them that even there a charred post had come through the barrier, 
proving it to be insuflScient. If they did not leave sufficient coal they 
would be subject to unknown dangers ; the fires would be resuscitated, 
and no doubt explosions would occur in internal parts of the goaf ; then 
as time went on the difficulty would be increased, and they would not be 
able to get their men to approach such workings. When he went to 
Leycett collieries there had been so many accidents from gob-fires and 
so many lives lost, that when a gob-fire arose every man ran out of the pit. 
The first gob-fire he sealed required nineteen stoppings, and if they had to 
attend these personally it made them consider the matter seriously. After 
a deal of thought, and knowing that he ran a great amount of danger, 
he concluded that the only safe way to reduce the danger was to reduce the 
number of stoppings to two or three, and by adopting this course he had 
been able to seal-off a district in about three or four hours from the first 



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80 DISCUSSION — SPONTANBOUS COMBUSTION IN COAL-MINES. 

discovery of the fire. With reference to the nature of the coal he might 
say that the Bullhnrst seam was of a bitmninous nature, and, regarding 
Mr. Binns' objection to the fundamental principle, g (" do not pass more 
ventilation through a district than is sufficient to keep the working-places 
and gob-edges free from gas "), he hoped it was explicit enough to all 
that they were not working with the colliery full of gas ; no doubt all the 
reports from the foremen that morning would be that they were free from 
gas. By working the seam in descending order a slight show of gas 
would be generally fomid at tlie edge of the goaf, while the gas in the 
internal part of the goaf would extinguish light without exploding. He 
was very pleased that Sir George Elliot, who had a large interest at 
stake, generally approved of the suggestions contained in his paper. 
He knew several instances of coal having been found on fire in pillars, 
and Mr. W. H. Wain would confirm his statement. He would be 
very pleased to attend any of the local institutes if the discussion on his 
paper could be held on a day convenient to himself. He might say that 
the rock-roof above the coal was of great thickness ; the next seam of 
coal (the Eight Feet) was. 50 yards above, and it also had a very hard 
roof, with the exception of about 2 feet of bass, which lay at the top. 
All coal possible was extracted, and all slack was sent to the surface and 
used for coking purposes. 

A unanimous vote of thanks to Mr. Settle was passed. 



Mr. Binns read the following paper on " Mining in New Zealand" :- 



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MIKINa IN NEW ZEALAND. 31 



MmiNG IN NEW ZEALAND.— (Continued).* 



By GEORGE J. BINNS. 



Part III. — OoAL-MiNiNG.f 

Richly as the colony of New Zealand has been endowed with metal- 
liferous ores, and plentiful as the natural stores of hydraulic power 
undoubtedly are, a great want would have existed had the deposits of 
mineral fuel been either deficient in quantity or quaUty, or so situated as 
to be approximately inaccessible. This latter point is not perhaps of so 
great importance, for while poor quality and small quantity are defects 
which can never be overcome, means of transport can always be devised. 
And this is, in the present case, fortunate, for while the coal-fields near 
the populated districts contain usually the inferior class of fuel, viz., 
the pitch coals, brown coals, and lignites, the true coals are found only on 
the inhospitable west coast of the South Island, to which reference has 
already, in a former portion of this paper, been made. The dangerous 
rivers and rough topography of this locality have greatly retarded progress, 
even in the case of metaUiferous mining (where such comparatively small 
quantities of material have usually to be dealt with) ; and in the case of 
coal-mining (where a great bulk must be moved to render the industry 
profitable), the hindrance has been even greater. Still, notwithstanding 
the great natural obstacles, and in spite of the cheapness of imported 
supplies, the coals of New Zealand are slowly but surely making their way, 
and establishing in the colony a healthy, steady trade, not subject to the 
violent fluctuations and vicissitudes of gold-mining, but growing and 
strengthening year by year. 

In this paper the following order will be observed : — 
1. — Geology and distribution. 
2. — General notes on the coal-fields. 

(1) Auckland coal-fields. ^ -^t ,1^ t , -, 
)^x -.ir 1 1 /. u !" North Island. 

(2) Mokau coal-fields. J 

(8) Picton coal-field. 

(4) Collingwood and Takaka coal-fields. 

(5) West Coast coal-fields. . o^ f i» t i 

(6) Canterbury coal-fields. 

(7) Otago coal-fields. 

(8) Southland coal-fields. 

• Tran. Fed, Ifut, vol iii., page 644, and vol. iv., page 69. 
+ 7Wd., vol. iv., plate VII. 



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82 MINING IN NEW ZEALAND. 

3. — Methods of working. 
4. — Machinery. 
5. — Legislation. 
6. — Accidents. 

7. — Total consumption, output, imports and exports, etc. 
8. — Quantity of existing coal. 

9. — Wages, strikes, benefit clubs, condition of the miners, etc. 
10. — Conclusion. 

1.— Geology and Distribution. 
The geology of New Zealand is both interesting and complex, and 
although the Director of the Geological Survey (Sir Jas. Hector, F.R.S.) 
has, with the small staff at his disposal, done wonders, it cannot be 
expected that in an exceedingly rough country like the one under discus- 
sion, anything like the detail of the British maps should have been attained. 
As the age of the coal-beds has, at various times, been disputed, it will 
perhaps be better to give the Director's own words on this important 
question : — 

" The Lowee Gebensand and Crbtaceo-Tbeti abt Formations (Ceetace- 
ous system op bocks). — The true and almost only coal-bearing formations of New 
Zealand. It is no doubt true that there are valuable deposits of fossil fuel occurring 
in various parts of the colony that have been variously referred to different geologi- 
cal periods during the past history of the Geological Survey, and the age of which 
is not yet satisfactorily determined. Some of these are now known to be of younger 
date than the Cretaceo-Tertiary period, viz., various deposits of lignite in the 
Wellington district of North Island, and possible occurrences of the same material 
in the Nelson and Westland district of the West Coast of the South Island ; also a 
deposit of the same nature found at Castlehill station in the Trelissick basin, 
Canterbury, and a bed of lignite overlying the marine beds of Miocene age within 
the watershed of the Upper Pareora, South Canterbury. 

More doubtfully to the same period must be referred the lignites or inferior 
brown coals of the Hakateramea and Waitaki valleys, 45 to 60 miles inland from 
Oamaru. 

There are also the thick deposits of fossil fuel occupying or found within the 
interior lake-basins of Central Otago, which have been generally referred to the 
Tertiary, sometimes to the late Tertiaiy, period ; but the evidence is by no means 
clear that all the known occurrences of such should be so referred. Again there are, 
farther to the south, in the Taieri, Clutha, and Mataura valleys various and some- 
times very thick deposits, in some places a mere lignite, in others a second or third- 
rate brown coal, which are usually considered as belonging to the Miocene period, 
but which, in more than one instance, will in the future have to be placed in the 
Cretaceo-Tertiary formation. There is even now no decisive evidence that the 
Mataura lignite near the railway-line opposite the township of that name is not of 
Cretaceo-Tertiary date, and it is certain, from the abundance of ambrite (derived 
from a coniferous tree closely allied to the Kauri of the North Island, but which has 
long since disappeared from the South Island) occurring in the deposit, that the 
vegetable matter composing it differed but little from that which formed the coal- 
seams of Green Island and Shag Point. The same remarks will apply, and with even 



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MINING IN NBW ZEALAND. 88 

g^ieater force, to the country north- west of Matanra, and flanking the Hokonui hills 
within the watershed of the Makarewa stream. 

Exceedingly modem-looking deposits of lignite are found along the eastern shore 
of New Harbour, between Invercargill and the Bluff, but the very modern date 
which has been assigned to these deposits rests on no further authority than the but 
slightly compressed condition (comparatively speaking) and inferior quality of the 
lignite. 

The brown-coal formation farther to the north-west at the Nightcaps, Morley 
Greek, and Centre Hill, there can scarcely be any question, belongs to the Cretaceo- 
Tertiary period ; but there are farther deposits more to the west, and on the coast- 
line towards Riverton and Orepuki, respecting the age of which there may justly be 
a difference of opinion, as the geology of this district has been worked out in the 
light of recent discoveries. 

But, besides in these localities named, it has been contended that the North 
Island coals wholly, and those of Nelson and the west coast of the South Island in 
part (excepting the bituminous coals), together with all the coals of the east coasts 
saving those found in the Malvern Hills (Canterbury), at Shag Point (Otago), and 
at Mount Hamilton (in the Southland district), should all be referred, not to the 
Secondary epoch, nor to a Cretaceo-Tertiary formation, but to some part of the 
Tertiary period. 

Practically, it matters not whether we consider our coal-fields to be Tertiary or 
Cretaceous, as regards the period when the coal-seams were deposited ; but it is of 
the very greatest importance whether they belong to one or two or more periods, 
and It is this that, under guise of a controversy as to the age and nomenclature of 
the beds, is the point at issue, and it is to prove the identity of the principal coal- 
formations of the colony that the Geological Survey has laboured during the past 
fifteen years. Indeed, so far as my own views on the subject are concerned, they 
have ever been what they are now — that we must regard all the great coal-deposits 
of New Zealand as belonging to one sequence of strata, or otherwise involve any 
systematic consideration of them in inextricable difficulty."* 

For convenience of classification and reference, the coals of New 
Zealand have been divided by Sir Jas. Hector as follows : — 

I. — Hydrous (coal containing 10 to 20 per cent, of permanent water). 

(a) Lignite. — Shows distinct woody stracture, laminated, or shows 
that structure on desiccation ; very absorbent of water. 

(b) Brown Coal, — Rarely shows vegetable structure. Fracture 
irregular, conchoidal, with incipient lamination ; colour, dark 
brown; lustre, feeble; cracks readily on exposure to the 
atmosphere, losing 5 to 10 per cent, of water, which is not 
re-absorbed ; bums slowly ; contains resin in large masses. 

(c) Fitch Goal. — Structure compact ; fracture smooth, conchoidal, 

jointed in large angular pieces ; colour, brown or black ; lustre, 
waxy ; does not desiccate on exposure, nor is it absorbent of 
water ; bums freely, and contains resin disseminated throughout 
its mass. 

• Report of Geological Explorations during 1886-87. (Sir Jas. Hector, K.C.M.G., 
M.D., F.R.S., Director), pages xxxii-xxxiv. 

YOU Vw-iaw-se. 3 



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84 MINING ]N NEW ZEALAND. 

11. — Anhydroufl (ooal containing less than 6 per cent, of water). 

(a) Glance Coal. — Non-caking, massive, compact or friable; 
fracture cuboidal, splintery; lustre, glistening or metallic; 
structure obviously laminated ; colour, black ; does not form a 
caking coke, but slightly adheres. This variety is chiefly 
brown coal altered by igneous rocks, and presents every inter- 
mediate stage from brown coal to anthracite. 

(d) Semi'Utuminoiis Coal. — Compact, with laminae of bright and 
dull coal alternately; fracture, irregular; lustre, moderate; 
cakes moderately or is non-caking. 

(c) Bituminous Cba/.-^Much jointed, homogeneous, tender and 
friable ; lustre, pitch-like, glistening, often iridescent ; colour, 
black, with a purple hue ; powder, brownish ; cakes strongly, 
the b^t varieties forming a vitreous coke, with brilliant metallic 
lustre. 

Although it is only the anhydrous coals which are of value for 
purposes of export, the pitch and brown coals, and even the lignites are, 
for local purposes, when their greater bulk is not an insuperable obstacle, 
very important factors in the prosperity of a district. 

Bituminous coal is found almost exclusively on the west coast of the 
South Island, at the base of a great marine formation underlying lime- 
stone, clay, and sandstone. The whole series has a thickness of several 
thousand feet, and contains, wherever it is found in contact with the older 
rocks, which are much metamorphosed and of indeterminate age, valu- 
able seams of coal. As in other parts of the world, the quaUty of the 
New Zealand seams appears to vary very much, according to the amount 
of disturbance and dislocation that they have suffered since their deposi- 
tion. Thus the lignites and inferior brown coals are comparatively free 
from faults ; the pitch coals and glance coals have been more disturbed, 
and the true coals have been in some cases subjected to great changes and 
dislocation. 

Lignites occur in many places, principally in the South Island, where 
they are found occupying the ancient rock-basins. They contain large 
fragments of wood, sometimes almost indistinguishable from recent 
specimens, and although they burn slowly, and with a somewhat un- 
pleasant odour, are of the greatest possible local value in the interior, 
where the great height above the sea renders the climate exceedingly 
rigorous, and timber exists either sparingly, or not at all. Deposits are 
also found in .the Lower Waikato basin and near Raglan, both in Auckland 
Province, and in Wellington and North Canterbury. 



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MINING IN NEW ZEALAND. 85 

Brown ooal is widely distributed, and is found on the Waikato river 
in the province of Auckland, at Kaitangata in Otago, and also in South- 
land, as well as in considerable profusion in Canterbury. 

Pitch coal, which is a really excellent fuel for local use, has been found 
at West Wanganui and Reefton in Nelson Province, at Shag Point in 
Otago,' on the Waikato river, and at Wangaroa in Auckland, and also 
in Southland. 

It will be hardly practicable to consider in detail the deposits of the 
colony in any other than their geographical order, commencing at the 
north. 

2. General Notes on the Coal-fields. 

NoBTH Island. 

(I) Auckland Coal-fields, 

The province of Auckland, which exhibits such a profiision of 

metalliferous ores, is but poorly provided with coal, for while the deposits 

are Mrly numerous, the quality, except in the cases of Kawakawa and 

Hikurangi is inferior, and even in these two instances, it cannot be 

described as actually first-class. There are five districts ; in the extreme 

north Wangaroa and Mongonui, next Kawakawa at the Bay of Islands, 

with Hikurangi between that area and the Whangarei field. Lastly Drury 

and Waikato, including Miranda. 

The Wangaroa and Mongonui fields do not at present require notice, 
for although the coal at the former place is of fair quahty, it has not 
been worked. 

The E[awakawa coal-field is on a different footing, as the output has 
been largely used by ocean-going steamers. The pit is now on the eve of 
exhaustion. Plucky efforts have been made to discover either an extension 
of the seam, or fresh deposits, by the aid of the diamond drill, but to no 
effect, and the output has decUned to 28,254 tons in 1891, raised by 70 
men. The total since the conunencemeut is 787,249 tons, in twenty-six 
years, during which time the concern can hardly be said to have been a 
commercial success. 

The coal is brought to bank by an engine-plane, and the pumping is 
(or was, for the writer fancies it is now stopped) carried on by means of 
heavy pumping-gear in a shaft to the dip. The seam was originally 
13 feet thick, but varies much, and the workings were pillar-and-stall. 
The roof is bad, and the slack very prone to spontaneous combustion. 
The port of shipment is 8 miles from the mine, and the produce is con- 



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36 MIKING IN NEW ZEALAND. 

veyed on a Government railway, which cost £86,288. The seam was 
originally found in 1868 by a person in search of Kauri gum, and it is 
a matter of deep regret that a good coal, worked by an enterprising 
company, under capable management, should not have brought a better 
reward. Two samples of the coal gave on analysis : — 





Per Cent 


Per Cent. 


Fixed carbon 


57-20 


55-59 


Hydrocarbons ... 


36-00 


38-10 


Water 


4-60 


4-19 


Ash 


2-20 


2-12 



100-00 ... 100-00 

The Hikurangi coal-field has been known for many years, but it was 
opened out only in 1890. In 1891, two mines were on the list, but as the 
railway was not then finished, the output had only a local sale, and was 
very limited. In fact, one mine put out nothing at all, and the other 
576 tons. The pit in operation was worked by an adit and horse haulage, 
and employed no machinery. The seam is 6 to 11 feet thick, and gives the 
following analysis : — 

Per Cent. Per Cent. 

Fixed carbon 42-70 ... 44-12 

Hydrocarbons 44-46 ... 46-89 

Water 5-93 ... 639 

Ash 6-91 ... 2-60 



100-00 ... 100-00 

The area of the field is stated to be 10 square miles, and no doubt 
when railway communication is established, the output will be considerable. 

The Whangarei district has the advantage of a railway leading to a 
port from which the coal can be shipped, and has been worked for about 
twenty-eight years. 

The Cretaceo-Tertiary rocks which lie unoonformably on the slates, are 
much obscured by newer volcanic formations. Formerly two mines were 
at work, but one of these is now closed, and the Kamo mine has the whole 
trade. This concern put out in 1891, 15,652 tons, which was a decrease 
from the amount raised in former years : the reason appears to have been 
that during that year a creep extended over the workings, and caused a 
cessation of work. 

The seam consists of a lustrous black coal, and is found to range up to 
14 feet in thickness : a little explosive gas is found, and the slack takes fire 
spontaneously. The shaft is 240 feet deep, and the cage is fitted with 
safety-catches and detaching-hooks. The system employed in working is 
bord-and-pillar. The analyses of a few samples are : — 



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MINING IN NEW ZEALAND. 87 





Per C«Mit. 


Percent. 


Percent 


Fixed carbon .., 


52-63 


49-08 


50-01 


Hydrocarbons .., 


34-30 


87-57 


37-67 


Water 


8-91 .„ »-24 


9-01 


Ash 


4-16 


4-11 


2-69 



10000 ... 100-00 ... 100-00 

To the south of Auckland city, and situated both on the large river 
Waikato and on the railway which skirts it for so many miles, is the 
Waikato coal-field, which is likely in the future to play an important part 
in the commercial history of the colony. 

The ooal produced is clean-looking, black and lustrous, suitable either 
for household use or steam purposes. It is, however, of low specific 
gravity, and desiccates so rapidly on exposure to the air that it is useless 
for storage. In the mines it is subject to spontaneous combustion. 

The seams were originally worked where they crop out on the banks 
of the Waikato river, and are found from 6 to 65 feet in thickness. In 
1891, five mines were in operation, which yielded a total of 55,859 tons, 
and employed 164 men. This number includes the Miranda mine. Two 
are worked by shafts, the others by adit level. At the Taupiri Extended 
mine the shaft recently sunk was put down with considerable diflSculty, 
as it was necessary to force down iron cyUnders, which met with obstacles 
in the form -of driftwood. Before the second shaft was sunk a circle 
of boreholes was made, to see if any similar obstruction existed. 
The cast-iron segments were then lowered, and the sand and drift 
removed by a dredge, without any water being pumped. The Taupiri 
Reserve mine, which turned out in 1891, 17,221 tons, worked under 
Lake Kimihia. By boring, the cover over the seam was found to be 
from 48 to 77 feet thick, mostly strong fireclay. The bords are 14 feet 
wide, and the pillars 21 feet, and of the 18 feet total thickness of the seam 
5 feet is left for a roof. It thus appears that laterally 40 per cent, of the 
support is removed, and it is reasonable to suppose that by flaking of sides 
and driving of cross-cuts another 10 per cent, will be lost. Tliis makes 
the spaces and pillars equal, which seems rather risky. 

At Maramarua creek, near the Miranda Redoubt, a mine was for some 
time worked on a seam 54 feet in thickness, or even more, but it was 
closed in 1890, after a somewhat disastrous career. The output for that 
year was 228 tons and the total 20,G68 tons. The pit was sunk on the 
edge of the Maramarua creek, a tributary of the Waikato river, and a canal 
costing £1,800 was cut to bring the coal to the main stream, by which it 
was brought down in punts to the railway siding at Mercer, where steam 



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38 MINING IN NEW ZEALAND. 

cranes raised the boxes from the punts and emptied them into the railway 
trucks. The lease consists of abput 1,000 acres, and the coal is of good 
quality ; but the mine appears to-have been injudiciously worked, or else it 
should have done better. Water, too, constituted a considerable drawback, 
and in 1887 it was necessary to draw water for 16 hours out of the 24. 
This work and the small sheaves which were used wore the winding rope 
out in two months. The following is an analysis of Waikato coal : — 

Per Cent. 

Fixed carbon 4708 

Hydrocarbons 38'24 

Water 17*60 

Ash 2-08 



10000 

(2) Mokau Coal-fields. 

In the Mokau district, which is situated at Taranaki, coal-seams have 
been known for upwards of fifty years, but the opening of the field was 
for many years retarded by the native ownership of the soil, and by the 
inaccessible position of the outcrops, which are on the Mokau river, 
24 miles from its mouth, and far from railway communication. The tide 
ascends the river for about 24 miles, and small steamers carrying 25 to 
100 tons go up to the mine. The coal is of fair quality, with the follow- 
ing composition : — 

Per Gent 

Fixed carbon 62*68 

Hydrocarbons 31*67 

Water 12*15 

Ash 8*60 

100*00 
but containing a good deal of sulphur. 

The seam worked at the Mokau mine is 8 feet thick, with a band 
of shale in the centre, from 2 to 8 feet in thickness, but gradually 
decreasing as the seam is followed into the hill. Another mine, called the 
Co-operative, is stated to be in liquidation. In 1891 the two undertakings 
put out 3,713 tons. 

Remarks on North Island Collieries. 

Until population becomes sufficient to render the trade in Whangarei 
and Waikato coal much larger — and with these must be included the 
Hikurangi district, which is as yet hardly touched — the output from the 
North Island will be small. In 1891, the yield was 104,064 tons, or 16*5 
per cent, of the total colonial output. This shows a decrease of 11,853 



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WININQ IN NSW ZEALAND. 39 

tons on the oatpat for 1890, which was the largest annual production 
known. In 1878, the percentage of the whole colony was 86'8, but this 
proportion has almost uniformly declined ever since, owing to the superior 
quality of the fuel obtainable elsewhere. 

South Island. 

Although the deposits of the North Island have proved of great benefit 
in the past, and will no doubt as settlement progresses become still more 
valuable in the future, it cannot be expected that by their aid any great 
export trade will be established. In the South Island, however, the 
case is different. On the west coast are seams, the produce of which 
can hold its own with that of any existing mines, and nothing is 
required but cheap methods of working and transport to enable these coals 
to compete successfully in the great markets of the world. 

Before passing to these busy and successful centres it will be requisite 
to take a passing look at the coal-fields of the northern part of the South 
Island, the first of which is that of Picton. 

(8) Picton Coal-field, 

On account of its unrivalled harbour and geographical position, the 
presence of coal at this place caused great excitement and resulted in the 
formation of a company. Unfortunately the geological features of the 
locality were utterly unfavourable, for the coal exists, so far as is known, 
only in a triangular patch cut off by faults on all' sides, and containing an 
area of about half a square mile. In all 700 tons of coal were raised, of 
excellent quality, but much faulted and crushed, and the works were soon 
abandoned, not, however, before a considerable sum of money had been 
lost in an undertaking, which, had the oft-repeated advice of the Geological 
Survey Department been followed, would never have been commenced. 
The analysis of the coal was as follows : — 

Per Cent. 

Fixed carbon 63*21 

Hydrocarbons 31"06 

Water 4*32 

Ash 1-41 



100-00 



(4) Colling wood and Takaka Coal-fields. 
A small coal-field exists at Takaka, on the shores of Golden bay, 
but it was for many years unworked, as the coal is of poor quality. 
The total output for 1891, when two mines (both opencast) were at work. 



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40 MINING IN NEW ZEALAND. 

was 410 toDS. The seam contains a band of sand 21 inches in thickness 
between two layers of coal, which measure respectively 2 feet and 2 feet 
6 inches in thickness. 

The Collingwood coal-fields proper may be divided into an eastern and 
a western portion, the latter known under the name of the West Wanganui 
coal-field. On the western side of the inlet bearing this name, which is of 
considerable extent, but almost devoid of water* when the tide is out, are 
found seams of coal which dip into the hills between the inlet and open 
water. Natural facilities for working are not great, and the coal is not 
of the very best quality, so the place has been neglected for many years. 
The analyses of two samples of coal from the locality are : — 





Percent 


Percent. 


Fixed carbon 


45-00 


5010 


Hydrocarbons ... 


38-90 


37-10 


Water 


4-80 


8-60 


Ash 


11-30 


4-20 



100-00 100-00 

On the eastern side of the range is the Collingwood coal-field, which 
comprises the Lower Coal-measures, containing bituminous coal, while the 
upper beds contain the pitch coal of West Wanganui. In the lower beds 
the seams, though of fine quaUty, are mostly thin, and contain numerous 
intercalations of bituminous shale. The lease of the one mine working 
in 1891 contains 990 acres, held direct from the Crown at an annual rent 
of £16, and a royalty (tlie writer believes) of 6d. per ton. 

The seams dip 1 in 10 into the hill and are worked long wall, the out- 
put being delivered by an adit level which cuts the seams. Two of these 
were worked in 1891, each having a thickness of 2 feet 6 inches, but not 
of clean coal. The workings are mostly to the rise, but a small dip area 
is drained by syphons. The total output up to the end of 1891 was 39,704 
tons, and the output for 1891 was 2,918 tons, produced by twelve men. 
Analyses of two samples of coal are : — 





Percent 


Percent. 


Fixed carbon 


53-29 


57-31 


Hydrocarbons ... 


38-18 


35-84 


Water 


2-06 


1-95 


Ash 


6-47 


4-90 



10000 ... 100-00 



The field is principally remarkable for the number of seams and their 
small vertical extension when compared with others in the colony. The 
harbour at present is fitted only for the smallest class of vessels, and the 



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MINING IN NEW ZEALAND. 41 

coal trade of the district — which contains some of the most valuable 
minerals found in New Zealand — is small and apparently stationary. In 
the northern poition of the field are some further outcrops which have 
received attention. The locality is known as Seaford, and the including 
strata are very much the same as those at Collingwood, that is to say, 
brown micaceous sandstones with pebble and grit-bands, all resting on a 
massive conglomerate. Two seams are known, the upper 2 feet in thick- 
ness, resting on a soft sandy clay, and the other as follows : — 

Ft. In. 

Coal 8 

Shale 6 

Coal 2 

As indicating to some extent the conditions of mining in this neigh- 
bourhood, it may be interesting to reproduce an estimate which was made 
in 1887 on the subject of working these seams : — • 









Ootfiperion. 








•. d. 


Capital, £10,000 at 7 per 


cent, interest « 




£700, on an 


output of, 


say, 28,000 tons 




per annum 


... 





6 


Sinking fund, £500 per annum 


4i 


Royalty 






3 


Mining 






6 


Haulage 






r, 


Outside labour 






6 


Inside „ 






1 6 


Management 






1 



Cost of coal per ton on wharf 10 7 J 

The analyses of two samples of coal are : — 





Upper Seam ^ 


Lower Beam. 


Fixed carbon 


51-37 


51-79 


Hydrocarbons ... 


39-72 


36-18 


Water 


4-38 


402 


Ash 


4-53 


8-01 



100-00 ... 100-00 

(5) West Coast Coal-fields. 

These actually extend, in broken masses, all the way from Collingwood 
to Jackson's Bay, but the first-named district has already been dealt with. 
The West Coast proper has two great coal-mining centres : Westport on 
the BuUer river and Greymouth on the River Grey. A small outlying 
district at Reefton may also be referred to. 

* Hector, Report of Geological Explorations^ 1887-88, pages 12 and 13. 



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42 MINING IN NEW ZEALAND. 

The Buller coal-field extends from the river of that name on the south, 
where the seams occur principally at an elevation of 1,800 to 8,000 feet 
above the sea, to the Mokihinui river on the north, where they descend 
to sea-level. The only exceptions to the elevated position of the southern 
portion of the field are some detached masses of crushed and faulted coal 
oocuring at the Waimangaroa and Ngakawau rivers. This is geologically 
interesting, but of small commercial value, as the product is so soft and 
incoherent as to be considerably lowered in value. Notwithstanding this 
defect, the Waimangaroa mines yielded 8,865 tons in 1891, but that at 
Ngakawau (which is owned by a Sydney, New South Wales, company) 
did not turn any coal at all, the reason given being that the seam has, in 
the dip, decreased in thickness to such an extent as to be unworkable. 
This seam was some years ago 16 to 18 feet in thickness, of which 8 feet 
was worked, the haulage being performed by a 6 inches double-cylinder 
engine. There is said to be a lai^e area of high-level coal, to reach which 
will require very extensive and costly works. The pit was worked many 
years ago without profit, indeed at a very heavy loss, and remained idle 
for a long time, but has been recently revived by the Westport Ngakawau 
Coal Company, whose object was partly to make coke for shipment to New 
South Wales for the Broken Hill mines, and partly to erect smelting 
works at Westport, to which silver ore from New South Wales might be 
brought as return freight. 

The writer is unaware to what extent these intentions have been 
carried out, but fears that the proposal to use New Zealand coke as fuel 
has not been a commercial success. This view is induced by the following 
extract from the annual statement for 1892 of the Minister of Mines for 
New Zealand (the Hon. R. J. Seddon, M.H.R.)?— 

In reference to our bituminous coal-fields, it is deplorable to see the waste of 
coal that is carried on at some of the mines. It will be recollected by some 
honourable members that when Mr. Kennedy, the managing director of the 
Brunner colliery, was giving his evidence last year before the Gold-fields Committee 
on some of the measures of the Coal Mines Act which was passed last session, he 
stated that about 500 tons of slack was emptied into the Grey river every month 
from the Brunner mine alone, which ought to be utilized and converted into a 
marketable commodity. There is a large market for coke of good quality in the 
Australian colonies, and by a proper system of manufacture the slack from the mines 
on the West Coast would make the finest coke in the world. I called attention to this 
in my last statement, and the fact^ arc fully borne out by the statements in a letter 
addressed to the Hon. John Lee, the treasurer of New South "Wales, by the secretary 
of the Broken Hill Proprietary Company, which has been published. In this letter 
it is asserted that the Broken Hill Company is using 1,000 tons of coke per week, 
but that all the colonial coke that has been tried is far inferior to that of either 
English or German manufacture, on account of the slack not being washed, 



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MINING IN NEW ZBALAND. 43 

prepared, dressed, and burned, ao as to make it more dense and hard. Colonial 
coke is foand to contain aboat 6 per cent, more ash than English coke, and this is 
stated to be equal t-o usinj? 80 tons more of the colonial than the English article 
every week, re lucing the capacity of the furnaces by 70 tons of ore per week, and 
also necessitating 70 tons more flux l)eing nsed for the same period, or, as the 
secretary states : " The use of colonial coke instead of English would mulct the 
company in the sum of £645 weekly, made up as follows: 80 tons at £5, £400; 
profit on 70 tons of ore at £2 lOs. per ton, £175 ; 70 tons of flux-iron and lime, 
£70." The secretary to the company cstimato.^ the loss with English coke at 7 per 
cent., and colonial coke 13 per cent., while he states that most of the colonial coke 
can stand no burden, but crumbles up quickly in the furnace, and fills the space 
around the tuyeres with fine coke, causing large losses in lead and silver, both 
chemically and mechanically. He further states that they find it inferior to such a 
degree that its use to a great extent is entirely out of the question, and leaves no 
other course open to the company but to use either the English or Continental 
manufacture. 

The whole of the blame must not in this ease be borne by the New 
Zealand coals, for the New South Wales seams are exceedingly prolific in 
ash, as may be seen on reference to the papers by Messrs. G. Blake 
Walker and S. H. Cox.* 

The Mokihinui coal-field, on the north, was many years ago the scene 
of an attempt to work, but the river is not a sufficiently good port for any 
large trade to be established, and it was only when the Government 
recognized the necessity of extending the railway from Ngakawau, a 
distance of 7 miles, that the future of the place began to look more 
bright. Two seams are known, one 23 feet thick, and the other less ; in 
1 891 the output was 4,540 tons. The Mokihinui Coal Company has been 
to considerable expense, having spent, among other things, £25,000 on 
a railway from the port to theii* mine. This is comparatively useless 
until the connecting link with the Government line, which will cost 
£86,600, shall have been completed. The analysis of a sample of coal 
gives the following composition : — 

Per Cent. 

Fixed carbon 56*01 

Hydrocarbons 37*17 

Water 2-60 

Ash 4-22 



100-00 



OoalhrooMaU Colliery. — To the average British mining engineer this 
coal-field would perhaps be the most interesting in the colony, not only on 
account of the splendid quality and great thickness of the seams, but on 
account of the wonderful situation of the mine. Two thousand feet above 
the sea, on the top of a bald bleak plateau of coarse quartzose grit, 

* Trans. Fed, Ingt.^ vol. ii., pages 268 and 321. 



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44 MINING IN NEW ZEALAND. 

covered only by thick moss and scattered mountain scrab, and inter- 
sected by vertical ravines of enormous depth, round which the seams crop 
out, is a large and flourishing colliery village, with large hotels, a school 
of mines, library, offices of the miners' union, bakeries, stores, and 
schools. The history of the Westport Coal Company, Limited, who own 
this mine, offers an example, if not of rich returns and uninterrupted 
prosperity, at least of extraordinary persistence and perseverance in the 
face of great natural difficulties. Commenced about the beginning of 
1878, several years elapsed before the works were in a state of completion. 
Bad weather, an excessively rough country, and numerous other obstacles 
retarded operations. Eventually coal was sent down, and then the pros- 
perity, which was to have poured in, was for some time delayed by the 
defects in the Westport harbour, by the unsuitability of machinery, by 
faults and changes in the seams, and by a hundred other unforeseen sources 
of trouble and loss. In order to meet the difficulties it was agreed to 
write off a certain amount of the capital, and the concern now may be 
said to be doing moderately well. In January, 1892, the chairman stated 
that during the preceding ten years the company had worked 1,000,000 
tons of coal, had expended £850,000, while the dividends paid had been 
£83,260, or a little less than 2 per cent, per annum on the capital. It is 
gratifying to note that for 1892 the profit was £22,043, which added to 
£6,358 brought forward from the previous year, was sufficient to pay 
a dividend and bonus amounting to about 10 per cent. 

The existence of coal in this district was known to the early settlers, 
but nothing systematic was done until the year 1874, when a detailed 
topographical and geological survey was undertaken by the Government, 
and carried out at a cost of over £5,000. The result of this was to prove 
the existence of coal-seams over a large area, which is, however, very 
much cut up by enormous denudation. The deposits occur principally at 
an altitude of 1,800 to 8,000 feet ; but towards the north, as has been 
mentioned, they come down to sea-level, and dip below it. The mapping 
of coal areas was unusually simple work, for numerous gullies and ravines 
caused the outcrops to be readily traceable. On receiving the reports of the 
Geological Survey Department the Colonial Government at once decided 
to proceed with the construction of a railway from Westport along the 
coast northwards to the Ngakawau river, a distance of nearly 19 miles, 
and also to improve the harbour, the average depth of which on the bar 
in 1879-80 was only 12^ feet. At the same time private enterprize was 
not dormant. Numerous leases were taken up, many by speculators without 
the means to work them. Finding, in 1877, that no effort was made to 



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MININa IN NEW ZEALAND. 45 

develop the field, the Government took steps to force the hands of the 
lessees, in order that the groand taken up might be either worked or 
relinquished. Many of the leases were then amalgamated, and a new pro- 
prietary, known as the Westport Colliery Company, took over the leases 
and liabilities of several of the original holders, and guaranteed to spend 
in two years £10,000 and produce a minimum output of 20,000 tons. 
In August, 1880, coal was brought into the market, and since that date 
the works have been so energetically carried on that in 1892 working 
single shift no less than 198,000 tons was put out from the Coalbrookdale 
mine. This required a total of 302 men, which gives 637'7 tons per man, 
or counting the underground staff only (238 men), an output per man of 
809 tons per annum. Unfortunately, there is no means of ascertaining 
on how many days the pit worked, but presuming this to have been five 
days per week, or 260 days, the daily output per man for a mine with 
exceptionally lengthy haulage would be 8 tons 2 cwts. 1 qr., or taking it 
at 4 days, 8 tons 17 cwts. 3 qrs. 

Finding the original capital insufficient the company was some years 
ago re-formed, with a nominal capital of £400,000, and although the 
return has not been so great as the shareholder deserved, yet prosperous 
times seem now to have dawned. This is in great measure due to the 
increased depth of water on the harbour bar, which averaged 23 feet in 
1892. 

The coal is a free-burning, lustrous, fuel, good for steam or household 
use, and the following analysis shows its purity in a striking degree : — 

Per Cent. 

Fixed carbon 63-81 

Hydrocarbona 31-88 

Water 308 

Ash 1-23 



100-00 

It is largely used for war vessels, and has great steaming power. The 
late Sir Jno. Coode, in his presidential address in 1889, before the 
Institution of Civil Engineers, said : " The bituminous coal found on the 
west coast of the South Island is declared by engineers ... to be 
fully equal to, if not better than, the best descriptions from any part of 
the world. The wonderful escape of H.M.S. 'Calliope' during the hurri- 
cane at Samoa, when her engines were tried to the very uttermost, has 
been attributed by her captain and the people of New Zealand, apparently 
with good reason, to the superior quality of this coal, which was being 
used at the time."* 

* Proo, Irut, Civil Bng., vol. xcix., page 23. 



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46 MINING IN NEW ZEALAND. 

The company owns two leases — one, the Coalbrookdale and Kawatiri 
of 2,479 acres, in which the present mines are worked ; and a new lease, 
as yet untouched, known as Granity Creek, and comprising 2,951 acres. 
The term is ninety-nine years, and the royalty 6d. per ton on large and 
small coal. The minimum rent merges in the royalty, but the company 
has a large dead rent to pay on the Granity Creek holding. Wages are 
high, and the men make a good deal of money. In 1889 the price for 
getting coal, large and small together, was 2s. lOd. per ton, and day wages 
were 10s. 

The writer is unaware whether any important alterations have been 
recently introduced into the haulage arrangements of the Coalbrookdale 
colliery, but as a detailed account of the appliances at work in 1890 was 
published by Mr. T. J. Waters, F.R.G.S., managing engineer at that time,* 
a short abstract may be included. 

The general system of mine haulage is endless-rope, which replaced an 
endless-chain formerly used and abandoned because of its frequent break- 
ages, sometimes thirty in a day. The main plane is (these data refer to 
the early part of the year 1890) 1 mile 60 chains in length, {ind is worked by 
a 3 J inches circumference plough steel- wire rope, of Lang lay, travelling 
at 2^ miles an hour. The engine has one cylinder 20 inches in diameter by 
48 inches stroke, and the driving wheel is 6 feet 8 inches in diameter, and 
lagged with cast-steel segments. The road varies much in gradient, the 
steepest being 1 in 10, and the diflference in level is 90 feet against the load. 
Two branch systems are worked with separate engines, one known as the 
iron-bridge road, opening up the field to the south-east, is worked by a pair 
of 6 inches cylinder engines, and has a total grade of 146 feet against the 
load, with a maximum of 1 in 5. The Coalbrookdale section is worked by a 
single 6^ inches cylinder engine, and runs in daylight up the bed of a 
creek, with the coal cropping out on each side, and numerous adits along 
its course. The rope travels at a speed of 1 mile per hour. 

Chains are used instead of clips, which were difficult to accommodate to 
the curves and gradients. Mr. Waters designed a very useful arrangement 
(Figs. 1, 2, and 8, Plate III.,) for attaching the chain, by means of which 
the attendants are enabled to hang the tubs on as conveniently when 
the rope is moving as when it is at rest. His description of the 
arrangement is as follows : — " It consists of a short length of chain, on 
one end of which is welded a ring, and on the other a hook. At each 
hanging-on place a pair of light steel springs are bolted to a cross sleeper. 

* Proceedings of New Zealand and South Seas Exhibition Mining Conference^ 
1890, G. J. BinnB, Hon. Sec. 



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MINING IN NEW ZEALAND. 47 

The loose ends of these springs are made to fit the rope and embrace it 
when pressed together. The hanger-on passes the chain three times round 
these springs where they embrace the rope, which slips between them as it 
runs, without imparting any motion to the chain clip ; hence the hanger- 
on is enabled to pass the hook end through the ring on the chain, and 
make it fast to the truck at his leisure. At the proper time the truck is 
pushed forward a few inches by hand, when the chain-clip slips off the 
steel springs and holds fast on to the travelling-rope, drawing the truck 
with it." 

The trucks are made of galvanized steel, 22 cubic feet in capacity, with 
cast-steel wheels of 24 inches gauge. The rails are 25 lbs. per yard on the 
full side, and 18 lbs. on the empty, with fished joints. The curve-rollers 
are of cast-steel 2 feet in diameter, placed at an angle of 80 degs. from the 
horizontal, so that the outside of the pulley is under the inner rail. 

The surface-inclines are on a large scale and have been very successful. 
As the mine mouth is about 2,000 feet above the sea, gravity is sufficient 
to lower the output, but the country is of an excessively rough nature, and 
great expense was incurred in making a road to accommodate railway 
wagons containing 6^ tons of coal, and having a gross load of 11 tons. 
The total length of the incline is 1^ miles, and the fall 1,800 feet to the level 
of the railway at the foot of the hills. The upper incline — for there are two 
— is 38 chains long horizontally, with a drop of 884 feet in that distance ; 
the maximum grade is 1 foot in 1 foot 4 inches. The drums are 10 feet 
6 inches in diameter, with cranks keyed on to the ends of the shafts, and 
attached by connecting-rods to two 12 inches pistons working in cylinders 
fitted with cataract-governors. This is found to be infinitely superior to 
the hand brakes formerly used, giving a much greater approach to safety, 
and a longer life to the ropes used by nearly 100 per cent., besides which 
the hand-brakes repairs amounted to over £300 per annum. The lower 
incline is 50 chains long, with a drop of 864 feet and a maximum grade 
of 1 in 2. The time occupied in running is 2 minutes for the upper 
and 2 1 minutes for the lower section, but both are run simultaneously. 
The road is 3 feet 6 inches gauge, laid with 40 lbs. or 42 lbs. rails. 

The Granity Creek inclines will be on the endless-rope principle, and 
are estimated to cost £50,000, which, with another £50,000 for rolling 
stock and opening up the mine, will make nearly a quarter of a million 
sterling spent in haulage and works. The mine tubs will come right 
down to the foot of the hill, and two inclines will be employed ; the upper 
one 70 chains long with a fall of 700 feet, and the lower one 51 chains 
long with a fall of 960 feet. Hydraulic brakes will be employed. It is 



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48 HIKING IN NBW ZEALAND. 

expected that coal will come down about the end of the current year, and 
the total output from the mines worked by this Company at Westport will 
shortly be probably nearly half a million tons per annum. 

About equidistant from Westport and Greymouth is the Reefton coal- 
field, situated on the Inangahua river. This area is limited in extent, and 
lies in patches on the upturned edges of the Maitai (Carboniferous) Slates, 
The coal is of very excellent quality, being in some cases bituminous. 

The following analyses will give some idea of its quality : — 



No. Locality. 


Nature 
of Coal. 


Fixed 
Oarbon. 


Hydro- 
carbon. 


Water. 


Aiih. 


1. New Durham Mine . 


.. Bituminous . 


.. 6409 . 


. 37-64 . 


. 4-36 . 


.. 8-91 


2. „ „ 


.. Brown 


.. 4802 . 


. 35-57 . 


. 14-21 . 


. 2-20 


3. Lankey's Creek 


.. Altered 


.. 5801 . 


. 33-19 .. 


. 6-79 . 


. 201 


4. Murray Creek 


.. Bituminous . 


.. 53-96 . 


. 35-87 . 


. 8-18 . 


.. 1-99 


6. Dudley Mine 


.. Brown 


.. 48-10 . 


. 35-88 .. 


. 14-21 . 


. 1-81 



During the year 1891, thirteen mines were at work, employing 20 men, 
and yielding 4,566 tons, most of which was consumed by the quartz- 
crushing machinery attached to the adjacent gold mines. The seams 
vary capriciously in thickness and dip. 

Other outcrops are known in the Upper BuUer district, but they have 
been only locally worked to a very small extent. 

OreymotUh District — The next district to consider is the Greymouth 
coal-field, second in importance only to that of Westport, and while the 
seams at the latter place are mainly far above the sea, and are therefore 
worked level-free, those at the former lie to the dip, and are approached 
by shafts or dip drives. It is true that the Brunner coal-mine, which is 
the oldest in the district, and has furnished by far the largest output, was 
for many years worked above water-level, but the bulk of the field will 
undoubtedly require haulage. 

The seams occur in grits and conglomerates, dipping in a westerly 
direction at 1 in 8, and the field is a good deal cut up by faults. The 
principal seam is 18 feet thick, and is exposed in the upper gorge of the 
Grey river, where it was originally worked and whence the coal was brought 
down the river in barges. At the present time the Government Eailway, 
which is 8 miles in length, takes the output from the mines to the 
port of Greymouth, where there is a fairly good harbour. 

At one time there were four mines, but they became merged into 
one company, and in 1892, for convenience in working, only two were 
open, viz., the Brunner and the Coalpit Heath, which are practically one 
mine. 



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MIKING IN NBW ZEALAND. 49 

The Branner colliery has been at work fcwenty-uine yeara, and had 
yielded to the end of 1891, 868,072 tons. The workings in 1891, when the 
ontpat was 75,729 tons were confined chiefly to the extraction of pillars, and 
the ventilation was prodnced by a 8chiele fan, a 16 feet Grnibal fan formerly 
employed having proved insufficient. The engine-plane is fitted with a 
pair of 14 inches cylinder engines with 18 inches stroke, and an electric 
hanlage-plant is in operation, but of this latter the writer has no details. 
There is also a rope-driven pump with a pair of 9 inches by 24 inches double- 
acting rams which raises the water 170 feet. The surface-works comprise 
a large brick and tile plant, where very excellent firebricks and gas retorts 
are manufactured, which find a ready sale not only in New Zealand but in 
Australia. 

A slack-washing and briquette plant has been erected, and it was 
intended to use the bye-products of the coke in the manufacture of 
briquettes, which are also made by the company at Christchurch on the 
east coast. In the early part of 1892, the demand for this class of fuel 
was stated to be very brisk, and the output, which was then 6 tons per day, 
was said to be finding a ready sale. 

In 1889, a committee of the House of Representatives took evidence on 
these mines, and among other details the following facts were elicited : — 
The average number of days worked was 8J to 4 per week, and the 
minimum wage was 128. per day. 

The Coalpit Heath colliery, which was originally in private hands, has 
now become the property of the Grey Valley Coal Company, Limited, half 
of which belongs to the Westport Coal Company, Limited. The workings 
lie to the dip of the Brunner colliery, and the coal is raised by the hauling- 
engine attached to that mine. At one time a rectangular shaft measuring 
10 feet by 6 feet and 280 feet deep was used with a single (18 inches by 
3 feet) cylinder engine. But the whole arrangement was crude and incon- 
venient. The seam is 18 feet in thickness, and of excellent quality. The 
workings were laid out on the bord-and-pillar system, and the pillars have 
to a great extent been removed. In 1891, the output was 69,592 tons, and 
since the commencement 429,991 tons have been raised. The workings are 
ventilated by a Schiele fan, and the pumping appears to be heavy, as there 
are on the published list no less than seven engines for this purpose vary- 
ing from 10 inches ram and 4 feet stroke, to 4 inches ram and 12 inches 
stroke. 

On the opposite side of the river to the Coalpit Heath mine is the 
Greymouth Wallsend colliery, now standing. It is a matter of great 
regret that this pit should have been set down, as it is no doubt the most 

YOU y^~-iaoM8 i 



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50 HIKING IK KEW ZEALAND. 

advanced example of mining in the colony. The shafts are circnlar, 
11 feet and 14 feet in diameter. The downcast, which was sunk in 1885, 
was lined for some distance with concrete blocks, grouted in with cement, 
instead of with cast-iron tubbing.* The winding-engine consists of a pair 
of 80 inches cylinders with 60 inches stroke working a 16 feet cylindrical 
drum fitted with steam brake and steam starting-gear. The boilers are of 
steel, 30 feet by 7 feet, and of the Lancashire type, working at 60 lbs. 
pressure ; head gear of iron, lattice girders 68 feet to centre of pulleys, 
which are 14 feet in diameter. A 80 feet Guibal fan airs the workings, 
and there is a small air-compressing engine for rock drills. The last out- 
put appears to have been raised in 1890, when 26,690 tons was the 
amount. Altogether only 205,539 tons has been raised from this fine pit, 
a large proportion of which must be credited to a small engine which 
worked a single shaft many years ago. When the coal trade expands, 
this property will be able to assume a worthy position. 

A small pit known as the Tyneside colliery, to the rise of the Grey- 
mouth Wallsend, has been abandoned for some years. 

Farther up the Grey river, and some distance from it on the north 
side, is the Blackball colliery belonging to a company recently floated on 
the London market ; there are two seams 4 feet 6 inches and 12 feet thick 
respectively, and a cross-measures drift 1 ,232 feet long has been constructed 
to cut them. In 1891, only 30 tons of coal was produced, but the works 
are not yet connected with the railway. In a colonial newspaper of recent 
date, the company is stated to be making fair progress with an aerial tram- 
way, presumably for the purpose of carrying the coal across the Grey river. 
A bridge 47 chains in length was originally proposed for this purpose, 
but the former method seems to have been preferred ; the first cost will 
no doubt be less, but whether it will prove an economical method for the 
purpose is a matter of opinion. 

The following average analyses of Greymouth coal may be given : — 





Per Cent. 


Percent. 


Per Oent. 


Percent. 


Fixed carbon 


53-26 . 


.. 53-50 . 


.. 59-38 . 


.. 5308 


Hyclrocarbons 


38-73 . 


.. 41-28 . 


.. 34-48 . 


.. 41-95 


Water 


1-48 . 


.. 1-41 . 


.. 1-05 . 


•99 


Ash 


6-45 . 


.. 3-81 . 


.. 4-09 . 


.. 3-98 



100-00 100-00 100-00 100-00 



On comparing these figures with the previously given analyses of the 
Westport coal, it will be seen that the latter contains less ash, and is 

♦ " CSoal-mining in New Zealand," by G. J. Binns, Trang, N,E, Intt,, vol. xxxv., 
page 194. 



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KINIKG IK NBW ZEALAND. 51 

poorer in hydrocarbona. On accounb of its richness in the latter respect 
the Greymouth coel has been lai^ely nsed for gas-making, and for many 
years it commanded 7s. to 8s. per ton more than that from Newcastle, 
New South Wales, bnt a very good gas-coal was recently found at 
Stockton, New South Wales, which ousted the Greymouth coal from the 
Australian markets. 

A yet undeveloped coal-field occurs at Point Elizabeth, on the sea 
coast, a few miles north of the Grey river. The harbour at that place is 
variously stated as being the best in New Zealand, and as being utterly 
unsafe. The writer has no personal knowledge of the locality. 

Owing to the uncertainty of the harbour at Greymouth the pits work 
very irregularly, not, it is stated, averaging 4 days per week. Mr. M. 
Kennedy, managing director of the Grey Valley Goal Company, recently 
stated that 12s. was the minimum earnings for a day of 7 hours. 

After leaving Greymouth the known areas of coal on the West Coast 
are scattered and comparatively small. Near Hokitika an attempt was 
made to work some thin seams, but without success, and in the neighbour- 
hood of the Haast river outcrops are found, but in such a rough and 
inaccessible position that any prospect of working them is remote. 

(6) CanUrhury Goal-fields, 

Although, as has been stated, the West Coast coal-fields alone supply 
coal of first-class quality, there is much fuel of a valuable nature to be 
found on the eastern side of the great axial range of mountains known as 
the Southern Alps. 

In the Province of Canterbury the principal development in this 
direction has been in the Malvern district, where the following four classes 
of coal are found: — 

1. Anthracite. 

2. Altered brown coals, in which the percentage of water is not high. 

3. Altered brown coals in which the percentage of water is high. 

4. Brown coals. 

The working of the first class is confined to a small pit, whence the 
supply for a sheep station is obtained, and the output from which has 
averaged only 10 tons per annum since the pit started, the return for 
1891 being nil. The locality is geologically interesting as the anthracitic 
quality of the coal is directly traceable to a dolerite flow, which overlies 
the seam. The analyses given vary very much, fixed carbon being 
letomed as constituting from 65*8 to 88*91 per cent, of the total, and 
ash up to 24*25 per cent. 



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52 MIKING IN NEW ZEALAND. 

Of the second claas the output has ceased, as the seams formerly worked 
dipped at very high angles, and were soon exhausted to water-level, below 
which it did not pay to follow them. The analysis shows : — 

Per Cent. 

Fixed carbon 63*29 

Hydrocarbons 32'04 

Water 12*65 

Ash 202 

100-00 
but the composition probably varies very much. 

Of the third class, a little has been raised for the requirements of a 
sheep station. 

The brown coals which constitute the fourth class were at one time 
largely mined, but the trade seems to have greatly fallen off, and in 1891 
the production was only 11,710 tons from 6 mines, whereas in 1884 it 
was more than double. The following analyses of the Springfield coal 
may serve as an example of the quality : — 





Percent 


Percent. 


Percent. 


Percent. 


Fixed carbon 


47*90 . 


.. 60-60 . 


.. 65-60 . 


.. 63*20 


Hydrocarbons 


41-80 . 


.. 38-80 . 


.. 30*90 . 


.. 23*60 


Water 


6*30 . 


.. 7-80 . 


4*20 . 


.. 8*20 


Ash 


4-00 . 


.. 2*80 . 


9*40 . 


.. 10-00 



100-00 100*00 100-00 100*00 

Though there are in the southern portion of Canterbury sundry small 
mines, none of them merit much attention, and it must be allowed that 
the mineral resources of this province are but poor. Fortunately, the 
natural agricultural advantages are so great as to amply compensate for 
mineral poverty, and a judicious and elaborate irrigation scheme has 
materially assisted agriculture. 

(7) Otago Goahfields. 

There were in Otago, in 1891, no less than 80 coal-mines on the 
official list, of which 20 did not produce, or at any rate were not returned 
as producing, any coal. The total yield was 164,870 tons, or 11,558 tons 
less than in the preceding ycjir, but of this total 110,042 tons came from 
5 mines, leaving 64,828 tons, or an average of 731 tons each for the 
remaining 55 working pits. Many of these are mere opencast excava- 
tions, into which carts are driven, and where the fuel is got as cheaply 
as it is probably ix)Rsible for it to be obtained under any circumstances. 

There are, however, several collieries which have attained an output 
of more respectable dimensions, and at which the appliances are of a 



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MINING IN NEW ZEALAND. 63 

saperior chaiacter. Continning the southward course adopted, the first 
of these is Shag Point colliery, situated on the seashore, about 40 milesf 
north of the city of Dunedin, and close to the main line of railway, with 
which it is connected by a short branch. The coal is of very excellent 
qnality, for a pitch coal, and has the following percentage composition: — 





Percent 


B 

Percent. 


Fixed carbon 


61-38 .. 


55-00 


HydrocarboiiB 


22-78 .. 


. 24-83 


Water 


19-92 .. 


. 13-89 


Afih 


5-69 .. 


6-28 



99-77 10000 

The measures dip E.S.E., at 10 degs., below the sea, where they have 
been explored to a small extent, and where in all probability a very large 
area exists. Rising to the west they form an anticlinal arch, which is 
terminated westward by a syncline, from the base of which they again 
rise, at high angles, into the hill known as Puke Ivitai. In 1880, the 
output was 86,066 tons, but it has since considerably fallen off, and in 
1891, only 7,814 tons was raised, making 4,298 tons less than the pre- 
ceding year, and a total of 228,242 tons since the opening of the workings. 
Two seams are mined, with a thickness varying in one case from 2 
to 12 feet, and in the other from 1 foot to 4 feet. The output is raised 
partly by a shaft measuring 16 feet 6 inches by 6 feet and 200 feet deep — 
(lately, the writer believes, this has been deepened) — and the water in 
tanks which automatically fill and empty themselves. The workings are 
free from gas, but the slack is remarkably subject to spontaneous com- 
bustion, and great trouble and expense have resulted from this fact. The 
roof also is very bad. 

In the same district, but in the trough of the syncline to which 
reference has been made, is the AUandale coal -mine, commenced about the 
year 1887. This seems already to have outstripped the older mine in 
output, for in 1891, the production was 10,785 tons. The seam is 7 feet 
in maximum thickness, and is worked by a dip drive, up which a small 
fixed engine draws the wagons. By now the pit-mouth is, presumably, 
connected with the railway by a tram road. 

The extension of the coal-measures beneath the Palmerston flat is a 
matter of conjecture, but it is to be hoped that this may prove to be the 
case, for the coal at this locality is of good quaUty and the situation 
favourable. 

No further important deposit is known until the city of Dunedin is 
passed, about 6 miles from which centre, on the main south line, is the 



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54 MINING IN NEW ZEALAND. 

Green Island coal-field. The coal here produced is of inferior qaality, but 
the seam (only one is worked) is ] 9 feet thick, and the measures consist 
of sands, clays, ferruginons gravels, shales, and fireclays, resting onoon- 
formably upon the upturned edges of highly metamorphosed rocks of 
unknown age, and dipping to the north-east at an angle of 1 in 10 beneath 
a thick sandstone of Tertiary age, which is again overlain by the volcanic 
rocks of the Dunedin basin. 

The field has been opened for about thirty-three years, and very 
numerous pits have been commenced, many of which have been lost owing 
to spontaneous fires, which are very rife. The tenure of the land is free- 
hold, and the royalty usually Is. per ton. A very large proportion of the 
seam is lost, as only 7 feet to 8 feet is worked in the first place by the 
room-and-rance system, and 3 feet more is got in coming back. In 1891, 
eight mines were at work, employing 188 men, who turned out 50,318 
tons, a considerable amount less than the output in some former years. 

Of these eight mines only three were connected with the raQway, 
and one (Abbotsroyd colliery) has private telephonic conmiunication with 
Dunedin. The produce of this field has, when first got, a lustrous 
appearance and dark brown colour, but desiccates rapidly on exposure to 
the air. It bums freely with a slightly unpleaaant smell, and leaves a 
bulky incandescent ash. Notwithstanding these defects, it is a fairly 
popular second-rate fuel in and about Dunedin. 

The mines are entirely free from explosive gas, and accidents of any 
kind are rare. 

The analyses are as follows : — 

Fixed carbon 

Hydrocarbons 

Water 

Ash ... ... 

Sulphur 

The Clutha coal-field, which next comes under consideration, is of 
large area, extending from the Clutha river on the south to 9 miles north 
of the Tokomariro river, a distance of 20 miles. 

The formation consists of conglomerates, sandstones, clays, and shales, 
with coal-seams, forming ranges of hills 700 feet high in the neighbour- 
hood of Kaitangata, and of less altitude to the north where they rise 
again on the flanks of Mount Misery, which is composed of schists. 

The first mine was opened in 1858, and although enjoying the 
advantage of financial assistance from the Provincial Government, was 
not a success. 



Percent. 


Per Gent. 


Percent 


40-84 


... 86-00 . 


.. 36-70 


36-67 


... 42-50 . 


.. 39*80 


18-67 


... 19-00 . 


.. 23-10 


3-92 


... 0-90 . 
... 98-40 . 


.. 1-40 


100-00 


.. 100-00 


... 


... 0-90 . 


.. 3-66 



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MINING IN NEW ZEALAND. 55 

In 1891, thirteen mines were at work, but if the output from the 
Kaitangata Railway and Coal Company's mine (58,945 tons) be deducted, 
the remainder is under 10,000 tons. The mine belonging to this company 
is a good example of a successfully-managed Colonial colliery, at which 
the coal is by no means first-class, but the working of which has been 
for many years highly profitable. Originally two companies held rival 
interests, but in 1880 the Kaitangata Railway and Coal Company bought 
out the neighbouring proprietors, and have since worked the whole area. 

The workable seams are four in number, the uppermost 3 feet 6 inches 
in thickness, and about 250 feet below this is a 9 feet seam which has not 
been worked At a further depth of 250 feet is the main seam, upwards 
of 35 feet in thickness. From the small seam about 7,000 tons was 
taken in 1876-77, but it has been for many years abandoned. About 
150 feet below the main seam is another, 19 feet in thickness, which was 
discovered by chance in 1889, but this enterprising company would appear 
not to be contented with even these quantities of coal, for the recent 
Dunedin papers state that they have purchased a diamond drill, capable of 
boring 2,000 feet, in order to prove the lower measures. The main seam 
is a good deal broken, and in places highly incUned ; the roof is a hard 
quartzose conglomerate, 70 feet thick, and auriferous, though not suffi- 
ciently so to be workable. The floor is moderately hard. In the original 
mine the seam dipped at 1 in 7, and on approaching the dip took a plunge 
at 45 degs. Inclines were driven on the full angle and levels on the 
strike close to the roof ; from these levels bords were driven to the floor. 
These workings eventually were closed, owing to a very heavy weight 
which came on. In the flat portion of the lease, the system was ordinary 
bord-and-pillar. About 8 feet of coal was got at fii-st, and afterwards 
as mnch of the top coal as possible. It will readily be understood that 
during this operation the working-places were of enormous height, and 
hence some change became necessary, when the following system was tried. 
At the first operation about 10 feet vertically was taken, and sufficient 
laterally to bring on a weight which crushed the pillars into the floor ; 
the whole area was allowed to settle, and the upper portion of the already 
partially-worked bords was then taken out. Of course, an enormous 
proportion of the seam was sacrificed by this system, but this appears 
unavoidable in cases of so thick a deposit. The coal is raised by an 
engine-plane 1,076 feet long and 9 feet wide by 6 feet 6 inches high, 
dipping 1 in 5 through the conglomerate and measures. This road, 
which is very hard in places, and in which some water was met with, was 
oonstmcted by means of rock drills driven by compressed air, in six 
months. 



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56 MININa IN NEW ZEALAND. 

The seam gives off some explosive gas, and the slack ignites very 
readily. In a paper read in 1890, Mr. Shore, the manager, gives some 
interesting details on this point, one of which may be reproduced : — 

A few years ago an incident occurred having a remarkable bearing on the rapid 
generation of spontaneous combustion under favourable circumstances. Pending 
the erection of air-compressing machinery, steam was temporarily conveyed along a 
dip tunnel for pumping purposes ; 3 inches pipes enclosed in a 12 inches by 12 inches 
wooden box filled with sand were used. The loaded trucks by accident left the 
tram rails. Anxious to get operations started, the men turned one of the trucks, 
loaded with wet dross, over on top of the b^ containing the steam-pipe. The 
temperature of the tunnel, which was used as an upcast, was 74 degs. Fahr. 
Twenty-two hours from being turned over the truck was found to be on fire. When 
removing the truck the dross (about 7 cwt.) had the appearance of newly-prepared 
asphalte. 

The machinery at this mine is very complete, and the following may 
be given as an example of what is used. In 1886, the shaft-engines which 
were used only for drawing water, consisted of a pair of 9 inches by 14 
inches cylinders, while the coal was raised by a pair of 9 inches by 12 
inches engines geared to a 12 feet drum. In case of accident to this 
engine, the haulage could be carried on by a single 20 inches by 54 inches 
engine used for compressing air in an 18 inches cylinder. Prom this 
compressor, at that date, two Tangye pumps were worked, one 1,800 feet 
distant, and the other 1,000 feet. In the mine waa a pair of 12 inches 
by 24 inches hauling-engines, also to be worked by compressed air, if 
required. A Harrison coal-cutter had been tried, but the writer believes 
that it has not been subsequently much used. Since that date the 
company appear to have been extending their operations, for so lately as 
February 9th, 1893, a notice appeared in the Dunedin papers of the 
purchase of a compressed-air pumping-engine, manufactured in that city 
by Messrs. A. & T. Burt. This engine seems, from the description, to 
consist of a 20 inches air cylinder with 24 inches stroke, coupled tandem 
on to a double-acting 5^ inches ram, and is to deliver 10,000 gallons per 
hour to a vertical height of 700 feet. It appears that this would give a 
somewhat excessive speed, but probably a pair of rams are used. The 
purchase of this pump has been necessitated by the deepening of the shaft 
which has been continued from 400 feet to 700 feet. In 1891, the output 
was 58,945 tons, and the undertaking has produced 629,051 tons in fifteen 
years. The means of transport is furnished by a private railway 4 
miles in length, on which the company spent £26,000, and the bulk of 
the coal is sold in Dunedin, which is about 50 miles distant from the 
pit's mouth, where it is a great favourite. It is black and glossy, with a 
conchoidal fracture and clean to the touch ; it bums freely with a cheerful 



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MINIKG IN NEW ZEALAND. 



A. 
Par Cent 


B. 
Percent. 


0. 

Percent. 


41-96 


39-42 


41-47 


35-49 


39-01 


37-28 


15-85 


16-71 


17-48 


6-69 


4-76 


3-76 


99-99 


99-99 


99-99 


0-838 


1141 . 


1-071 



blaze, forming a hot fire, and leaving a bulky incandescent ash. The 
following analyses were made in 1890 by the writer after the coal had 
been for some time exposed to the atmosphere :— 



Fixed carbon 
Hydrocarbons 
Water 
Ash 



Salphnr 

In addition to the property described above, the company owns a 
freehold coal-bearing estate of 2,200 acres near Tokomariro, 41 miles 
from Dunedin. 

The working of the Kaitangata colliery has been for many years very 
free from accident, but in 1879, before the enforcement of mining 
regulations by (Jovemment, a disastrous explosion occurred, which killed 
8 persons, and left the 81 remaining in the mine to die of after- 
damp. In a few weeks the sum of £15,878 waa subscribed in the 
colony for the benefit of the widows and orphans, £10,000 of this sum 
being raised in Otago alone. In the beginning of 1890, £14,681 had 
been paid in direct alimony and £563 in expenses; and notwithstanding 
this large disbursement, there was £11,645 left to the credit of the fund. 
The writer gathers from the Colonial newspapers that legislative action 
has been taken, and that the capital has been placed in the hands of 
trustees as a fund for general mining accidents. 

Near the Kaitangata Railway and Coal Company's mine, a company 
known as the Castle Hill Coal-mining Company has of late years been 
engaged in sinking a shaft. Some time ago a borehole proved the 
coal at 400 feet, and a small shaft was put down, striking a good seam. 
Since then a 18 feet circular shaft has been commenced, which was to cut 
the coal at 600 feet. Brickworks were established and a railway built to 
connect with the existing private line. Unfortunately a great deal of 
water and running sand was met with, which overpowered the pumping 
appliances, and when the sinking was resumed, after standing for some 
time, the sides were found to be damaged. Information under date 
February, 1898, is to the effect that the shaft is abandoned, and the 
workings will be approached by a cross-measure drift dipping 1 in 4^. 

Scattered throughout the interior of Otago are numerous small 
mines, many of them openwork, and employing only a man or two for 
a short time. 



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58 MINING IN NEW ZEALAND. 

(8) Southland Coal-fields, 
The coal-fields situated in the province of Southland are mostly only 
of local importance. Exception to this may perhaps be made in favour 
of the Nightcaps Coal Company's freehold mines which produced 14,485 
tons in 1891. There appear to be three separate mines close together, 
working seams varying from 8 feet to 15 feet in thickness and employing 
83 men. The fuel is bright, black, clean-looking, burning well and 
containing — at any rate as regards one seam — much fossil resin. The 
analysis is as follows : — 

Percent 

Fixed carbon 47*81 

Hydrocarbons 21'04 

Water 2924 

Ash 1-91 



100-00 

8. Methods of Working. 

The almost universal system of working is by bord-and-pillar, or the 
Scottish room-and-rance, which is very similar. Generally the pillars 
are left much too small, but sometimes the plan is properly laid out and a 
fair proportion recovered. The roofs vary very much : on the westeni coast 
of the South Island, hard gritty rock; in the Kaitangata mines, hard 
coarse conglomerate; at Kawakawa, sandstone; in the Waikato and 
in many of the brown-coal-mines, running sand. 

There are on the oflScial list 161 coal-mines, but of these 20 are 

dormant, and the remaining 141 may be classified as below. In some 

parts of the oflScial reports two or more pits are occasionally grouped, 

which accounts for the discrepancy noticeable between this table and 

that given on page 78. 

Worked by shafts — 

Steam-power used 8 

Horse-power used 6 

Hand-power used 2 



Total worked by shafts 


,,, 


16 


Worked by adits— 








Engine-power used .. 




17 




Horse-power used .. 




25 




Hand-power used .. 


... 


31 




Not stated 




4 




Total worked by 


adits 


• a. 


77 


Opencast 


... 


... 


42 


Method not stated 


... ... 


... 


6 



Total 141 



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MINIKa IK NEW ZEALAHB. 59 

4. Maohinert. 

Of the New Zealand coal-mines, only twenty-five in 1891 utilized 
engine-power for raising the mineral, and this is accounted for by the 
fact that so much outcrop coal is found level-free, and at present horse or 
hand-power is usually found suflScient. In a few cases good winding and 
hauling-engines are employed. As regards ventilation, it appears that 
there are three fans, five furnaces, one steam-jet, one steam-jet and 
furnace combined, while two mines owe their ventilation to steam-pipes 
in the upcast shaft. Compressed air is occasionally, but seldom, employed; 
electricity as a motive power in the one case already noted. Electric 
signals are common. A Harrison coal-cutter was tried at Eaitangata, 
where also power rock-drills were very successfully introduced. Mechanical 
Btokers were tried at Greymouth and abandoned. Telephones are very 
largely utilized. 

5. Legislation. 

In many respects the law for r^ulating collieries in New Zealand 
(The Coal-mines Act, 1891) is similar to that at present in force in G^reat 
Britain, but as the minerals are in almost every case Crown property, the 
subject of leases forms a not unimportant portion. The valuable coal-fields 
of Westport and Greymouth are under the control of the Harbour Boards 
established for these places, and although leases may be granted by the 
Minister of Mines, the application must first come before the local body 
interested, and (apparently to guard against a monopoly) any proposed 
amalgamation of leases may be vetoed by the Legislative Assembly. 

The following are, shortly stated, the usual terms of lease. (1) Term 
not to exceed sixty-six years ; (2) area not to exceed 2,000 acres, and dead 
rent to be not less than Is. or more than 6s. per acre ; (8) royalty to be 
not less than dd. or more than Is. per ton on all coal raised ; (4) when the 
royalty exceeds the dead rent, the latter ceases ; (5) no wayleave or surface 
rent is paid, but only such surface as is actually required shall be taken ; 
(6) any person requiring "free access, egress, and regress" upon the land 
leased for the purpose of constructing any adit or tunnel, shall have 
power to do so, on obtaining the sanction of the Minister of Mines (on 
the reoonunendation of a Warden or Commissioner of Crown Lands), but 
coal-mining is not to be interfered with; (7) all timber required for 
mining purposes may be cut, but otherwise timber on leases is reserved to 
the Grown ; (8) all minerals other than coal are excepted ; (9) power is 
reserved to the Crown to resume possession on paying compensation; 
(10) in case of neglect on the part of lessees to work during three 



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60 MINING IN NEW ZEALAND. 

months, notice may be given to resmne: if this be neglected for an 
additional three monihs, the lease may be determined, and ''the Qneen, 
the Governor, or the Minister may enter on the demised premises and 
take possession of all buildings and improvements thereon." The next 
clause, however, states that the lessee shall be allowed two months to 
remove plant, but not buildings. (11) If at any time " the lessee neglects 
or refuses to pump the water out of any underground working for three 
days after the inspector has given the lessee notice in writing to do so, 
the inspector may, if it shall appear that such neglect or refusal to pump 
the water is likely to be prejudicial to the safety of any adjoining mines, 
or to the prejudice of the Crown, as proprietor, enter upon the mine and 
take possession of the pumping machinery, and employ men to work such 
machinery for pumping out the said workings, at the cost of the lessee ; 
and any costs so incurred shall be deemed a debt due to Her Majesty by 
the lessee." (12) The lessee is bound, if so required, when the mine 
is being worked, to supply the Government, or any private railways, 
or any steamships with coal at current rates, each railway or vessel with 
not more than seven days' supply — strikes excepted. 

Inspectors are to be appointed, every one of whom is to be the holder 
of a first-class certificate, and the clauses relating to the appointment of 
managers are similar to those in the British Act. 

A board of examiners is appointed by the Government, and the 
examination fee is £1, which enables the candidate, in case of failure, to 
have a second try, within three months. The questions set by the 
examiners are reasonably easy (see Appendix A). There are two 
grades of certificates, three in fact, as in case of a mine employing six 
men or less, a "permit from the inspector" is required. Not only for 
managers are certificates requisite, but also for engine-drivers, who raise 
men either in a shaft or plane. Due provision is made for certificates 
of service in both cases. "Any person of good repute producing a 
certificate of competency from any duly constituted and recognized 
authority outside the colony " can obtain a certificate either as manager 
or eugine-driver. 

No female and no boy (that is, under 13) shall be employed in or 
about any mine, and the next section enacts that "no boy or youth (that 
is, under 18) shall be employed for more than forty-eight hom*s in any 
one week, exclusive of the time allowed for meals, or more than eight 
hours in any one day, except in cases of emergency. But no person 
shall be deemed guilty of an offence against this Act for a contravention 
of that part of this section relating to the time for which persons shall 



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MINING IN NEW ZEALAND. 61 

not be employed below-ground, if he prove before any two justices, not 
being interested in any mine in which such person or persons are 
employed, that there were special circumstances to render such contra- 
vention necessary for the proper working of the mine ; and that such 
contravention was not injurious to the workmen employed in the mine." 

Section 29 enacts that no person under 18 is to have chaise of an 
engine used for lowering or raising persons, but this is somewhat super- 
fluous, as Creneral Rule 21 forbids any person under 21 to have chaise 
of any steam-engine or boiler used in the working of any mine. 

No person in charge of steam machinery shall work for more than 
eight consecutive hours, exclusive of the time used in raising or exhausting 
steam and of meal times, and of ^^ any time in which such person is 
employed in case of breakage or other emergency." 

Section 31 provides for the usual registers of "boys employed in 
connexion with the mine," but as section 27 directly prohibits the 
employment of any boy ** in any capacity," these registers will not be 
largely used, and the numerous references to this class of labour might 
well have been left out. 

Section 82 contains the General Rules, which are prefaced by the 
" reasonably practicable " clause. 

General Rule 1 defines the " adequate amount of ventilation to be not 
less than 100 feet of pure air per minute for each man and youth, and 
horse, pony, donkey, or mule, which shall sweep undiminished along the 
airway through each working-place." 

By General Rule 15 cage covers are defined as "constructed of iron 
not less than one quarter part of an inch thick, and shall be securely hung 
on hinges and fitted with sloping sides, so as to be readily lifted upwards 
by persons within the cage." 

General Rule 20 requires ropes and chains to be tested "to carry 
twice the weight of the ordinary load" before being used, and also, 
where men are raised and lowered, a similar test is to be applied once 
in every three months. 

Boilers have, according to General Rule 32, to be subjected to a 
hydraulic test once in every six months. It may be mentioued that 
inspectors under "The Inspection of Machinery Act, 1882," make regular 
examinations of all steam-boilers, and grant a certificate, beyond the 
pressure stated on which the boiler is not to be worked. A charge is 
made for this certificate, exceeding — (the writer speaks from memory) — 
very considerably the premium paid in England by boiler-insurance com- 
panies for examination and insurance. 



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62 MINING IN NEW ZBALAND. 

In mines liable, " in the opinion of an inspector," to an inundation or 
inburet of water, such escape roads as may be prescribed by the Minister 
of Mines are to be constructed, and also provision for the safety of the 
men during the period of any inundation or inburst of water in such mine. 

General Rule 41 contains the "two hours before commencing work" 
examination clause. 

General Rule 44. — All safety-lamps are to be of a pattern approved 
by the inspector. 

Special rules are not framed as in Great Britain, but are contained 
in an appendix to the Act. There is, however, power for framing any 
additional rules which may be advisable. 

Section 44. — It is compulsory on the inspector to immediately investi- 
gate any complaint from a miner. 

Section 45. — Every mine where there are underground workings — 
(N.B. — In 1891 there were ten mines on the list, all with underground 
workings, and furnishing a total output of 869 tons, or under 37 tons 
each per annum) — is required to keep a plan, which must be made up 
every six months by a certificated manager, a duly-qualified mining 
engineer, or a surveyor authorized as such by the Surveyor-General, A 
copy to be sent to the inspector, who may, if he thinks fit, have a check- 
survey made, and if the original plan should prove to be incorrect the 
inspector can recover the cost of the check. Power is reserved for the 
cancellation or suspension of certificates. 

Section 52 provides that "Any accident occurring in a mine shall 
be prifna facie evidence that such accident occurred through some 
n^ligence on the part of the owner." 

Section 53 provides for compensation of employes injured through 
non-observance of the Act, and may best be given in extenso: — " If any 
person employed in or about any mine suffer any injury in person, or be 
killed, owing to the non-observance in such mine of any of the provisions 
of this Act, such non-observance not being solely due to the negligence of 
the person so injured or killed, or owing in any way to the negligence of 
the owner of such mine, his agents or servants ; the person so injured, or 
his personal representatives, or the personal representatives of the person 
so killed, may recover from the owner compensation by way of damages 
as for a tort conmiitted by such owner ; and the amount of such compen- 
sation with the costs of recovering the same when determined, shall 
constitute a charge on the mine and mining plant, in or about which such 
person was so employed, and all charges arising under the provisions of 
this section shall, as between themselves, be paid rateably. 



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MINING IN NEW ZEALAND. 68 

Such compenaation may be recovered under the provisions of * The 
Deathfiby Accident Compensation Act, 1880,' or 'The Employers' Liability 
Act, 1882,' which shall respectively be applicable, according to the circum- 
sfcances of each particular case ; subject, however, that notice of injury 
having been sustained may be given under the last-mentioned Act at any 
time within three months from the occurrence of the accident causing the 
injury, instead of within six weeks as in the said Act mentioned. 

Nothing in this section contained shall take away from any person 
any right to take proceedings in respect of a claim for compensation for 
injury or death by accident, which he may have under any other Act 
other than this, if he prefer to proceed under such Act, but in such case he 
shall forfeit any right he may have to take proceedings under this section. 

Notices of accidents and the provisions of coroners' inquests are as 
usual, but as distances are so great the Minister of Mines may authorize 
some person to act for the inspector. The writer remembers a case when a 
police-constable, who acted in this capacity, reported that the evidence 
*' disclosed no blame to the Mines Department." Where practicable one- 
half the jurors are to be miners. 

Section 59 deals with the resumption of land for mining purposes, and 
has an important bearing on the question of mineral rights. The pro- 
visions are as follows : — 

(1) All lands which, previous to the commencement of this Act, 
have been alienated or agreed to be alienated from the Crown, 
whether by way of absolute sale, or lease, or for any lesser 
interest, shall, with the consent of the owner or occupier 
thereof respectively ; and 

(2) All lands which, after the commencement of this Act, may be so 
alienated, or agreed to be so alienated, from the Crown, but not 
expressly for coal-mining purpose, shall, without the consent of 
owners or occupiers thereof respectively ; and 

(8) All native lands which have been alienated since the dOth day 
of August, 1888, or which hereafter may be alienated by the 
native owners thereof, to any person other than Her Majesty, 
except lands alienated expressly for mining or coal-mining 
purposes; 

Shall be liable to be resumed by Her Majesty for coal-mining purposes 

on paying full compensation to the owner and occupier thereof for the 

value of the land and improvement so resumed. 

Section 60 enables the Governor, on behalf of Her Majesty, to contract 

with the owner or lessee of any coal-mine either in native, private, or 



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64 MINING IN NEW ZEALAND. 

Grown lands for the acqoisition of such mine, " Provided that resamption 
and acquisition under this and the preceding section shall not be complete 
nor take effect until a resolution of the Legislative Council and the House 
of Representatives shall have been passed sanctioning the same. Any 
land so resumed or acquired may be worked by the Minister on behalf of 
Her Majesty, unless the Legislative Council and the House of Repre- 
sentatives shall by resolution otherwise determine." 

Section 61 deals with the question of access to and wayleave through 
lands required, and is of great interest as bearing on the recommendations 
of the Royal Commission on Mining Royalties, whose report has recently 
been published, "Where, for the purpose of working any mine, it is 
required to carry any work on, or over, or under any private land, or to 
take any such land, or any part thereof, for mining works in connexion 
with such mine, the Governor, on the application and at the proper cost 
and charges of the owner of the said mine, may take such land, or any 
part thereof, under *The Public Works Act, 1882,' as for a public work 
within the meaning of such Act. All provisions of the said Act shall 
apply accordingly for the purpose, but the effect of the Proclamation 
taking the land shall be to vest such land in the applicant instead of in 
Her Majesty, and all proceedings after the aforesaid Proclamation in 
respect of compensation and otherwise in respect of complying with the 
said Act shall be had against the applicant, who shall be deemed to be the 
respondent, and shall be liable in respect of such taking in the same 
manner and to the same extent as Her Majesty or the Minister for Public 
Works would be in respect of taking land for a Government work under 
the said Act." 

Section 63. (Encroachment.) This section authorizes the Minister 
of Mines, on affidavit of any person claiming to be legally or equitably 
interested in any mine, to authorize the inspector, together with a " mining 
surveyor or experienced miner," to enter and survey, but the complainant 
is first to deposit a sum not exceeding £100 as security. 

Section 65 deals with the flooding of adjoining mines, and enables any 
owner of a mine, who shall have left a barrier not less than 83 yards 
thick along his entire rise boundary, to recover from his neighbour, who 
may wilfully or negligently allow any water to overflow or percolate, a 
proportionate amount of the cost of pumping such water. 

Section 68 requires the usual annual returns and also "any other 
imformation connected with the mine the Minister may from time to 
time require," and it authorizes the Minister to publish the result of such 
returns. 



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lUSVSQ IN NBW ZEALAND. 65 

Section 69 is perhaps the most remarkable provision in the Act. It 
is a direct and heavy tax on a particular industry, and goes beyond the 
contract entered into between the Crown and the lessees, opening up a 
question of the gravest importance. As an attempt to relieve distress it 
is no doabt admirable, but, as was expressed by a leading mining man 
in New Zealand in a recent letter to the writer, " The principle of such 
a fund I do not object to, but I think it should be subscribed to by 
all parties concerned, starting with the lessor and ending with the men.'* 

Its provisions are, shortly stated, as follows : — The owner of every coal- 
mine shall contribute one halfpenny per ton on the output of bituminous 
mines and one farthing per ton on any JUignite sold, during the preceding 
three months, and shall pay this into the Post Office Savings Bank to the 
credit of a fund to be called the " Sick dtid Accident Fund" in connexion 
with the miners* associiatiou pf the district. In case of there being no 
miners* association the money is to be paid to the credit of a fund known 
as "The Coal Miners' Relief Fund.*' These moneys are to be operated 
upon ''only by the persons appointed in that behalf by the miners* 
association of the district, in accordance with regulations to be from time 
to time made by the Governor,** and where no such association exists the 
Minister of Mines and the Public Trustee are to act. The inspectors of 
mines are empowered to examine colliery accounts in order to see if the 
owners pay up regularly, and the penalty for not doing so (which goes to 
the credit of the fund) is two pounds for every pound or fraction of a 
pound not paid. There is one redeeming feature. In case of damages 
for injury, the amount to which a workman may be entitled from the 
accident fund is to be taken into account. 

The final section in the Act provides that no contract for the supply 
of coal shall be binding in case of- a strike. 

6. Accidents. 

As will be observed on reference to the following tables, coal-mining 
in New Zealand is subject to approximately the same proportion of 
accidents as occur in other countries, but owing to the limited number of 
men employed, the death-rate per thousand is very variable (Fig. 4, 
Plate III.). Many of the fatalities have occurred in small mines, where 
the owners have neither sufficient capital to provide proper appliances, 
nor in many cases the skill requisite for using them, were they at hand. 
Thus, in 1888, when there were four deaths, half this number took place 
in two mines, with a joint output of 30 tons. 

VOL. V.-1MI-8B. 5 



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66 



MINING IN NEW ZEALAND. 



Prior to 1879, statistics of mining accidents were not kept, and the 
following table therefore commences with the year 1880 : — 



Table op Number op Deaths peb 1,000 Persons Employed in 
New Zealand Coal and Lignite Mines. 



Year. 






Deaths par 1.000. 


1880 2-50 


1881 


,, ,,, ,,, 


1-04 


1882 


.* *•. 




1-91 


1883 

1884 






1-60 
2-34 


1886 


•• ••• 




206 


1886 






000 


1887 


.. ..« 




2-66 


1888 


,, ,,, 




2-36 


1889 






2-37 


1890 


•• ••• 




4-33 


1891 


.. 




2*86 



Average from 1879 inclusive (but not connt- 
ing the Eaitangata explosion, which 
occarred prior to the enforcement of 
mining r^ulations) to the end of 1891 



233 



The following tables show the classification of accidents to the end of 
1887 :— 

Table op Pebcentage op Total Accidents in Coal-mines, New Zealand^ 

1879 to 1887 INCLUSIVE (NOT COUNTING THE KAITANOATA EXPLOSION). 



Above- 


PerOeat 


Falls of ground 


1-23 


Trucks 


1-86 


Powder 


1-23 


Miscellaneous 


5-55 


Below— 




Falls of roof and sides 


... 66-79 


Trucks 


... 14-81 


Explosions of powder 


4-32 


„ „ fire-damp 


4-94 


Falls of timber 


4-32 


Miscellaneous 


1-23 


8haft«— 




Falls down 


0-62 


In shafts 


3-08 



986 



86-41 



3-70 



99-97 



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MINING IN NEW ZEALAND. 



67 



Of deaths alone the percentage for that period was as follows : 



Canse 
Explosion of gas 

Falls below ground 

Tracks below 

Shafts : 

Falls of gravel above ground 
Asphyxiated in shafts 



Per Gent 
4-51 

68-18 
908 
4-54 
9-08 
4-54 

99-96 



Thus 77*26 per cent, of the total fatalities is due to falls of ground. 

The average number of men employed per life lost from 1879 to 1891 
(inclusive) was 428'7, and the average tonnage raised per life lost was 
149,524 tons. 

7. Total Consumption, Outpxtt, Imports and Exports, btc. 

With only one very small exception, the total consumption of coal 
has gone on from year to year steadily increasing, as will be seen on 
reference to the following table and to Fig. 5, Plate III. : — 

Table of Total Consumption op Coal, New Zealand. 



Year. 


QiuQtIlyiB 
Tom. 


IncreMe. 


DeoTOMe. 


Peroentace 
iDoraMe. 


DeereaM. 


1877 


294.980 














1878 


832,445 


37,466 


— 


12-7 


— 


1879 


382,099 


49,654 


— 


1409 


— 


1880 


416,200 


34,101 


— 


8-4 


— 


1881 


460,598 


44,398 


— 


10-6 


— 


1882 


503,609 


43,011 


— 


8-5 


— 


1883 


538,132 


34,523 


— 


6-41 


— 


1884 


622,921 


84,789 


— 


16-7 


- 


1885 


638,894 


15,973 


— 


2-56 


— 


1886 


651,364 


12,470 


— 


1-96 


— 


1887 


652,899 


1,535 


— 


0-20 


— 


1888 


687,658 


84,659 


— 


5-30 


— 


1889 


675,218 


— 


12,340 


— 


1-79 


1890 


714,932 


89,714 


— 


6-88 


— 


1891 


765,019 


50,087 


— 


6-64 


— 



The total output (Fig. 5, Plate III.) also shows a 
except in the year 1889. 



increase. 



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68 



HINIMO IN NEW ZEALAKD. 





Table op Coal Outputs, New Zealand. 




Y«w. 


QnanUtyin 
Too., 


laermac. 


DeoTOMe. 


^ssssr! 


Decrease. 


1877 


138,984 


• __ 


_ 


1 


__ 


1878 


162,218 


23,234 


— 


16-71 1 


— 


1879 


231,^18* 


69,000 


— 


42-5 


— 


1880 


299.923 


68,705 


— 


29-7 


— 


1881 


837,262 


37,339 


-^ 


12-4 


— 


1882 


378,272 


41,010 


— 


; 10-8 


— 


1883 


421,764 


43,492 


— 


10-5 


— 


1884 


480,831 


59,067 


— 


' 140 


— 


1885 


511,063 


30,232 


— 


1 6-3 1 


— 


1886 


634,353 


23,290 


— 


4-5 1 


— 


1887 


658,620 


24,267 


— 


4-5 1 


— 


1888 


613,896 


55,275 


— 


1 9-9 , 


— 


1889 


586,445 


— 


27,460 


— 


4-4 


1890 


637,397 


60,952 


— 


1 8-7 ' 


— 


1891 


668,794 


31,397 


— 


4-6 1 


— 



Imparts.— The imports of coal into New Zealand will probably never 
entirely cease, for though the native coal is plentiful and good, New 
South Wales fuel will always command a market. This arises mainly 
from the fact that the latter colony is a very large customer for New 
Zealand farm produce, and the vessels, rather than come back empty, 
bring coal as a return freight. The following table and Fig. 6, Plate III., 
show the history and position of the trade : — 

Table op Imposts op Coal into New Zealand. 



Year. 


Qiumtityln 

T0D8. 


Inoreaae. 


Dccreaoo. 


Incpoaae. 


Peroenta«e 
Deoreaae. 


1877 


155,996 


_ 


_ 


_ 




1878 


174,148 


18,162 


— 


11-6 


— 


1879 


158,076 


— 


16,072 


— 


9-2 


1880 


123,298 


— 


34,778 


— 


220 


1881 


129,962 


6,664 


— 


512 


— 


1882 


129,582 


— 


380 


— 


0-2 


1883 


123.640 


— 


6,042 


— 


4-66 


1884 


148,444 


24,904 


— 


201 


— 


1885 


130,202 


— 


18,242 


— 


12-28 


1886 


119,873 


— 


10,329 


— 


7-93 


1887 


107,230 


— 


12,643 


— 


10-65 


1888 


101,341 


— 


5,889 


— 


6-49 


1889 


128,063 


26,722 


— 


26-37 


— 


1890 


110,939 


— 


17,124 


— 


13-87 


1891 


125,318 


14,379t 


— 


12-96 


— 



• The abnormal increase of the year 1879 over that preceding is due to the &ct 
that a large number of coal-mines which had not previously received official notice 
were at that time, owing to the enforcement of legislation relating to mining, added 
to the list. By this means the number on the record was raised from 30 to 90. 

t This increase was caused to some extent by the strikes in New Zealand, which 
caused foreign coal to be poured in. For instance, one line of steamers imported 
4,621 tons from Europe. 



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MINING IN NEW ZEALAND. 



69 



Betusn Showing the Quantity and Value of Coal Impobted into 
New Zealand dubino the Yeae ending Dsgembee 81st, 1891. 

Oountries whence 
Imported. 

United Kingdom 

Victoria 

New South Wales 

Queensland 



Quantity 


Value. 


in Tons. 


£. 


962 


1,030 


1,246 


1,304 


120,775 


.. 116,320 


2,335 


1,768 



Total 



125,318 



£120,422 



Exports. — In considering the exports of coal from the colony, it is 
necessary to distinguish between that which is actually exported to a 
foreign country there to be consumed, and that which is put on board 
the direct steamers to be burned on the voyage. In Table A, this 
quantity is counted, where obtainable, as consumed within the colony ; 
and in table B, it is treated as export. (See Fig. 6, Plate III.) 



Table A.— Expobts op CtoAL fbom New Zealand (Counting Dibect 
Steamer. Consumption as Consumed in the Colony). 



Year. 


Quantity in 
Tons. 


Increaae. 


Decreaoe. 


PerotfUtage 
Increase. 


Feroentage 
Deoreaie. 


1878 


3,921 


^^ 





" 





1879 


7,195 


3,274 


.. — 


83-5 


— 


1880 


7,021 


— 


174 


— 


2-4 


1881 


6,626 


— 


395 


— 


5-6 


1882 


4,245 


— . 


2,381 


— 


36-9 


1883 


7,172 


2,927 


— 


68-9 


— 


1884 


6,354 


— 


818 


— 


11-4 


1885 


2,371 


— 


3,983 


— 


62-6 


1886 


• 


~ 


— 


— 


— 


1887 


12,951 


— 


— 


— 


— 


1888 


23,783 


10,832 


— 


83-6 


1 


1889 


39,290 


16,507 


— 


65-2 


— 


1890 


33,404 


6,886 


— 


— 


14-9 


1891 


29,003 


4,311 


— 


— 


12-9 



* The figures for 1886 ai-e not obtainable. This has destroyed the continuity of 
the table. 



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70 



MINING IN NEW ZEALAND. 



Table B.— Expobts of Coal fbom New Zealand feom 1884, with the 
DiBECT Steam f.b Consumption tbbated as Expobt. 



Yen. 


QiunUtyin 
Tods. 


InoreMO. 


DeonMe. 


PeroenUge 
InoTOMe. 


Peroentace 
DeereMo. 


1884 


6,354 














1886 


45,493 


89,139 


— 


— 


— 


1886 


47,037 


1,544 


. — 


3;39 


— 


1887 


44,129 


— 


2,908 


— 


6-18 


1888 


68,087 


23,968 


— 


64-29 


— 


1889 


82,670 


14,683 


— 


21-4 


— 


1890 


76,388 


— 


6,282 


— 


7-6 


1891 


99,464 


23,076 


— 


30-2 


— 



The following table gives details of the countries to which the above 
amounts for 1891 were sent : — 

Bbtubn Showing the Quantity and Value of Coal Ezfobts fbom 
New Zealand dubing the Teas ending Degembeb 31st, 1891. 



OoantriM (o which 
Exported. 
United Kingdom* ... 


Quantity 

iuTona. 

70,371 


Vftlue. 
78,060 


Victoria 


167 


102 


New South Wales ... 


8,952 


8,269 


Qaeensland 


70 


81 


South Australia 


7,701 


3,360 


Western Australia ... 


89 


46 


Tasmania 


19 


22 


Norfolk Island 


74 


80 


Fiji Islands 


3,421 


2,602 


U.S. America (East Coast) 


2 


2 


Chili 


407 


609 


South Sea Islands ... 


8,201 


7,636 


Total 


99,464 


£100,668 



Of this, 2,968 tons, valued at £3,848, was foreign coal, the rest was 

New Zealand produce. 

Table of Pbopobtion of Impobted Coal to Total Consumption, 
New Zealand. (See Fig. 7, Plate III.) 

Peroentaceof 



1878 
1879 
1880 
1881 
1882 
1883 
1884 



Imported Goal 

to Total 
Oonsumpiion. 

52-3 


1886 


41-4 


1886 


29*6 


1887 


28-21 


1888 


26-7 


1889 


22-9 


1890 


23-8 


1891 



Percentage of 
Imported Coal 

to Total 
Oonsomption. 

20-3 
18-4 
16-4 
14-7 
18-9 
16*6 
16-37 



^ For direct steamers. 



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MINING IN NEW ZEALAND. 



71 



The following tableB, and Fig. 5, Plate III., show the ontput of coal 
and percentage increase or decrease per annum for each island : — 

Output op Coal, Nobth IbiiAnd, Nbw Zealand. 



Yen. 


Ontpotln 


IncreaM. 


Deoreaw. 


Peroentoge 
InoroMe. 


Peroeatace 
DeoreMe. 


1878 


58,900 




^ 





__ 


1879 


75,070 


16,170 


— 


27-4 


— 


1880 


96,346 


21,275 


— 


28-3 


— 


1881 


90,734 


— 


5,611 


— 


618 


1882 


96,151 


5,417 


— 


5-9 


— 


1883 


92,762 


— 


3,389 


— 


3-5 


1884 


103,903 


11,241 


— 


10-81 


— 


1885 


111,734 


7,831 


— 


7-63 


— 


1886 


104,794 


— 


6,940 


— 


6-2 


1887 


98,710 


— 


6,084 


— 


5-8 


1888 


108,538 


9,828 




9-9 


— 


1889 


94,255 


^ 


14,283 


— 


13-16 


1890 


115,917 


21,662 


— 


22-9 


— 


1891 


104,064 


— 


11,863 


— 


10-2 



Output of Goal, South Island, Nkw Zealand. 



Yev. 


C^ta 


InoreMe. 


DMT6M0. 


Poroentace 
Increaae. 


Peroeotogo 
I>«oraaae. 


1878 


103,318 


^ 











1879 


156,148 


52,830 


— 


51-1 


— 


1880 


203,248 


47,100 


~ 


301 


— 


1881 


246,529 


43,281 


— 


21-2 


— 


1882 


282,121 


35,592 


— 


14-4 


— 


1883 


329,002 


46,881 


— 


13-07 


— 


1848 


376,828 


48,826 


— 


14-8 


— 


1885 


899,829 


22,452 


— 


5-9 


— 


1886 


429,559 


30,230 


— 


7-57 


— 


1887 


469,910 


30,351 


— 


7-06 


— 


1888 


505,367 


45,447 


— 


9-87 


— 


1889 


492,190 


— 


13,167 


— 


2-6 


1890 


521,480 


29,290 


— 


5-9 


— 


1891 


564,730 


43,250 


— 


8-29 


— 



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72 



MINING IN NEW ZEALAND. 



The following tabfe indicates more clearly how the ratio of increaae in 
the South; Island exceeds that in the North : — 



Table Showing Pkbcentagb op Total Output op Coal Contbibutbd 

BY THE NOBTH ISLAND, NBW ZEALAND. 

Peroentaffe 
Contrfbuted by 
North iBluid. 
21-8 
21-8 
17-67 
17-6 
16-07 
18-18 
15-5 



1878 


Peroentogo 

North iBluid. 
36-3 


1885 


1879 


32-46 


1886 


1880 


23-1 


1887 


1881 


26-9 


1888 


1882 


25-4 


1889 


1883 


17-2 


1890 


1884 


21-6 


1891 



The following table gives some details of the outputs of the various 
districts for the years 1890 and 1891, and the approximate total output 
since records have been kept : — 

Table showing the Output op Coal pbom the vabious Mining Distbicts, 

AND the INCBEASE OB DECBEASB POB THE TEABS 1890 AND 1891, TOGBTHEB 

WITH THE Total Appboximate Quantity op Coals Pboduced. 



DisMct 


Output. 


Inoreaae. 


Decrease. 


Approxliiiate 

Total Output 

toDecSlst, 

1891. 


1890. 


1891. 


Kawakawa 


30,367 


28,264 


_ 


2,113 


769,246 


Whangarei 


19,633 


16,228 


— 


3,406 


265,860 


Waikato 


64,729 


56,869 


— 


8,860 


696,629 


Mokau 


1,188 


3,713 


2,526 


— 


4,901 


Pelorus (Picton) ... 


— 


— 


— 


— 


711 


West Wanganui 
and CoUingwood 


4,092 


3,328 





764 


40,114 


Westport 


170,406 


206,184 


35,778 


— 


1,191,867 


Reefton 


6,010 


4,666 


— 


1,464 


47,740 


Greymouth 


118,847 


146,361 


26,604 


— 


,1,622,030 ! 


Malvern 


15,083 


14,775 


— 


308 


274,328 1 


Timani 


1,430 


1,488 


68 


— 


5,442 


Otago 


176,428 


164,870 


— 


11,558 


2,218,982 


Southland 
Totals 


29,184 


24,178 


— 


5,006 


194,236 


637,397 


668,794 


64,865 


33,468 
V'" — — — — ^ 


7,131,986 








Net increj 


we, 81,397 





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MINIKO IN N£W ZBALAKD. 



78 



The following table classifies the diJSFerent varieties of coal : — 

Tablk showing the Difpebent Classes of Coal fbom the Mines in 

New Zealand. 



Nam«ofOoaL 


Ontpat of OoftL 


InoreMe. 


DeoreMe. 


Approximate 

ToUI Outpat 

toDecSUi, 

1881. 




1890. 


1891. 






Bituminoas 


323,712 


387,839 


64,127 


— 


8,531,749 


Pitch 


124,598 


96,979 


— 


27.614 


1,112,966 


Brown 


171,725 


161»904 


— 


9,821 


2,275,364 


Lignite 

Totals 


17,367 


22,072 


4,705 


— 


211,908 


637,397 


668,794 


68,832 


37,436 


7,131,986 








Net increase, 31,397 





The following table gives an indication of the relative number of men 
employed and average output per man in the different sized mines. It 
supports what the writer has mentioned relative to the inconstant employ- 
ment and consequent small output of the very small pits : — 

Table showing the Numbeb of Coal-mines in Opebation, the Numbeb 
OF Men Employed, and the Output of Coal peb Man. 



Number 
ofMUnas 
Working. 


Number of Miners 
Employed in each Mine. 


Total 

Number 

of Men 

Employed. 


Output of 

Goal During 

1881. 


Arerage 


96 

16 

6 

16 


1 to 4 men in each 

5 to 10 „ 
11 to 20 „ 
21 men and upwards 

Totals 


196 

107 

96 

1,295 


Tom. 
49,416 

30,587 

22,141 

566,650 


Ton*. 
252 

285 

233 

437 


133 


1,693 668,794 


395 



The discrepancy between the number of mines given above and that 
given in the table on page 58 has been akeady explained. 

8. Quantity of Existing CoAii. 

The diflficulty of determining the total quantity of coal contained in 
any country has been well exemplified in the case of Great Britain, and 
it is obviously impossible in a place like New Zealand to make even an 
approximate estimate. Sir James Hector, however, whose knowledge of 
the coal-fields is unequalled, has published his opinion on this point,* as 
follows : — 

♦ Report of WesUand Coal-Jieldt CommUtee, 1889, page 104. 



Digitized by VjOOQ IC 



74 MINING IX NBW ZBiJiAND. 

Rough Estimate of the Pbobable Area and Quantities Contained 
IN the New Zealand Coal-fields. 







Acreage of 




No. 


Name. 


CoAl-measnrea. 


Ton^. 


1 


Kawakawa 


19,200 


11,360,000 


2 


Waikato 


64,000 


51,200,000 


3 


Mokau 


16,800 


32,720,000 


4 


Collingwood ... 


46,000 


16,000,000 


5 


Karamea 


13,400 


6,360,000 


6 


Wangapeka 


12,800 


6,520,000 


7 


Matiri 


10,800 


4.700,000 


8 


BuUer 


... 115,200 


138,240,000 


9 


Reef ton 


12,800 


5,120,000 


10 


G^rey 


44,800 


53,760,000 


11 


Clarence 


6.400 


2,560,000 


12 


Malvern 


9,600 


7,680,000 


13 


Somers 


1,920 


768,000 


14 


Kakahu 


3,200 


1,280,000 


16 


Bhag Point 


19,200 


8,600,000 


16 


Green Island ... 


9,600 


11,280,000 


17 


Clutha 


32,000 


51,000,000 


18 


Winton 


16,000 


12,800,000 


19 


Nightcaps 


32,000 


25,000,000 






Total 


. 443,948,000 



9. Wages, Strikes, Benefit Clubs, Condition of the 
Miners, etc. 

Wages have already been referred to, and vary from about 12s. per 
day on the West Coast, where living is expensive, to 78. below ground and 
6s. above on the eastern side of the South Island. 

The following are some prices for contract work in 1890 : — Stone- 
drift, 6 feet by 6 feet, mostly conglomerate, dipping 1 in 7, haulage 
supplied by owners, otherwise the price includes labour and explosives, £3 
lOs. 6d. per yard ; drifting, 6 feet by 6 feet in coal shales, including tim- 
bering, £1 19s. per yard ; coal-heading, 4s. to 7s. 6d. per yard, and 4s. 
per ton for coal, and Is. for slack ; coal-getting (in Canterbury), 8s. per 
ton for all-over 1 inch riddle, regular work. 

It is always difficult to calculate the earnings of miners, especially 
when the number employed is somewhat variable, as is the case in New 
Zealand. The method employed in the last Mines Department report of 
the colony is as follows : — The total quantity of coal raised in tons is 
multiplied by six shillings, which is supposed to represent the average cost 
in wages of getting a ton of coal. This gives £200,638, and as 1,693 
men were employed (1,277 below and 416 above ground) the average 
earnings of each is £118 lOs. 2d. per annum, a very large sum, but one 
which, when the cost of living is taken into account, must be heavily dis- 
counted before being compared with the remuneration in Great Britain. 

Strikes unfortunately are not unheard of, and have been carried to a 
pitch unknown in England. An institution known as the ^^ complete 



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MINING IN NEW ZEALAND. 75 

boycott " has been established, which requires some explanation. A and 
B (say) own a coal mine, and also a woollen factory. A is also a partner 
in a merchant's business. The men at the colliery strike or are locked out. 
The labour leaders give notice that A and B are to be boycotted. No 
member of any carriers' union is to touch a bale bound for the factory or 
a package from the store. No railway or steamship is to carry a single 
article bearing the name of either the woollen company or the merchant's 
business, under penalty of an immediate cessation of work on the part of 
all hands. This desperate style of warfare which involved workmen who 
had nothing whatever to do with the matter under dispute, and simply 
amounted to a display of strength, wrought its own cure, and ended in a 
bitter disappointment to the men — ruin in fact to many — enormous loss 
of trade to the Colony, and great privation for women and children. 
The capitalists at once rose to the occasion and worked their undertakings 
with " free labour." 

On the West Coast of the South Island in 1891, it became necessary to 
employ non-union men, working under police protection, and housed and 
fed on the works. In order to ensure their safe transit from the railway 
train to the mine, special constables were enrolled and the somewhat 
unusual course was adopted of swearing in, as temporary guardians of the 
peace, about 100 of the most prominent union men, who were accordingly 
drawn up in line to preserve order, while those who were coming to take 
their work marched between. 

Benefit societies and sick-and-accident clubs were conmion at all the 
larger works, but the direct taxation of the owners to provide for require- 
ments of this nature will presumably have checked, if it has not kiUed, 
these organizations. 

As regards wages, money is tolerably plentiful, and men can, if they 
like, save. The West Coast is wet and rough, and living is expensive ; 
houses too, as in all new countries, are at a premium, but land can easily 
be obtained, and the style of dwelling considered in the colonies sufficient 
for a small family does not take long to run up, and is easily sold. In 
the agricultural districts, the colliers frequently have a piece of ground 
and often keep a horse, while shooting and fishing are in places to be had 
at very small cost. Free education for children is usually at hand, but if 
not, and there should be a railway, they travel free to the nearest station 
where there is a school. Libraries and reading rooms, schools of mines, 
and other means of passing the time profitably are plentiful, and there 
are so many local bodies that a considerable amount of attention is taken 
up with what may be called "parish politics." 



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76 MINING IN NEW ZEALAND. 

While colliery working in some parts of New Zealand is an operation 
requiring great perseverance and large capital, there are many places 
among the brown coals and lignites where a pick and shovel, with a few 
days' or weeks' labour, will suffice to open what is undoubtedly a coal- 
mine. Nearly all over the interior of Otago are patches of lignite, some- 
times hidden by the surface-soil and vegetation, and sometimes exposed in 
the beds of watercourses. When these seams penetrate deep into the 
soil an adit is required instead of a simple opencast working ; and then, 
in addition to the actual tools required for breaking ground, comes the 
necessity for the purchase of a truck, a little sawn timber for rails, and 
some prop-wood, which is very dear in places, costing as much as Is. per 
foot for a 6 or 6 feet prop. Even in this case the requisite outlay is not 
large, and for men who have a love of independence, an undertaking of 
this nature, even though it may not hold out any prospect of riches, ofifers 
the inducement of freedom with frequently a comfortable living. Many 
proprietors of these small concerns get the coal, tram it out, and cart it 
to the consumer. This system dispenses entirely with the middleman, 
and brings to the fore a class of self-reliant hard-working men who 
occasionally are fortunate enough to escape over-competition, and by dint 
of perseverance and labour attain a competency. 

As years go on the opportunities of working without capital will grow 
less plentiful, and as railways increase the trade will fall into the hands of 
the larger companies. 

10. Conclusion. 

The writer trusts that in the foregoing pages he has given an impartial 
and faMy accurate account of coal-mining in New Zealand. The figures 
dealt with are in many cases small, as compared with the armies of work- 
men and stupendous output of the mother country, but the colony is 
equipped with stores of mineral fuel which will some day materially help 
it to assume its proper position among the nations which are springing up 
under the old flag. As an integral part of this great empire its future 
prospects cannot be without interest to those who desire to see English- 
speaking miners and mining engineers supreme in all quarters of the 
globe. 

Part IY. Kauri-gum. 
As a fossil resin dug from the earth kauri-gum has undoubtedly a 
place among the mineral productions of the colony, and, as will be seen 
from the following table, it forms a by no means unimportant article of 
export. It is the fossil turpentine of the Kauri (Dammar a australis)^ 
which is still found growing in the northern portion of the colony, and 



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MIKING IN NEW ZEALAND. 77 

occurs as far sonth as Taranaki. Though used principally in the manu- 
facfcure of varnish, it is stated to be employed as a substitute for amber, 
which it very much resembles. As the method of mining for kauri-gum 
is very simple — nothing more is required than a spear with which to find 
it, a spade to dig it out, and a sack to carry it away in — it is a frequent 
refuge for people who have not suflBcient capital to embark in any other 
industry, who are not over-fond of work, but like a free and open-air life, 
and who desire to obtain something which is readily convertible into 
cash. As the climate of the region where it occurs is very mild, and the 
country comparatively open, but little hardship need be encountered by 
the " gum-digger." 

Table, showing Export of Kaubi-gum fob the tkabs 1890 and 1891, 

AND ALSO THE TOTAL AMOUNT EXPORTED FROM JANUARY 21 8T, 

1853, TO December 31st, 1891. 

Toni. Value. 

1890 7,438 ... £378,563 

1891 8,388 ... £437,066 

From January, 1853, to 

December Slat, 1891 ... 143,018^ ... £5,831,743 

Apropos of kauri-gum, the mineral ambrite may be mentioned, though 
it has not as yet been commercially utilized. It occurs plentifully in many 
places, and has been described by Dr. von Hochstetter,* as follows : — 
'' Fossil resin embedded in the coal, sometimes in pieces from the size of 
a fist to that of a man^s head, but usually only in smaller groups. It is 
transparent, very brittle, and has a conchoidal and quite glossy fracture. 
Colour changes from a bright yellow to dark brown ; is easily ignited, 
much more so than kauri-gum, burns with a steady iast-sooting flame, 
and develops a bituminous rather than an aromatic smell. Mr. Richard 
Maly found as a mean of three chemical analyses of this fossil resin : — 

Carbon 

Hydrogen 

Oxygen 

Ash 

10000 

yielding the formula C*" H" 0*. It shows great indifference to solvents ; 

by friction it becomes electric ; hardness, 2 ; specific gravity, 1*034 at 12 

degrees Beamur. It is sufficiently characterized to deserve a special name, 

but it comes so near to real amber in composition that it deserves the 

name of ambrite." 





Computed. 


76-63 


76-65 


10-58 


10-38 


— 


12-78 


0-19 


0-19 



The writer has now to conclude with a word of explanation what has 
been to him a congenial labour. The colony of New Zealand is an exten- 
sive and varied tract of country, embracing every variety of topography, 

* New Zealand, 1863, English edition, page 79. 



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78 MINING IN NEW ZEALAND. 

a complex and representative geology, and a very large number of mineral 
products. In endeavouring to lay before this Institute an account of the 
present condition of mining in that colony the greatest difficulty ex- 
perienced has been not in obtaining materials for a paper, but in choosing 
from the great mass available, sufficient to give an idea of the mineral 
riches and methods of working them, without drifting into prolixity and 
superabundant detail. The writer has had perpetually before him the 
fear of incurring reproach by referring in too eulogistic terms to the 
future prospects of New Zealand mining enterprise, while it has been his 
constant endeavour to do justice to the resources of the country in which 
he lived and laboured for so many years. 

To the small but intrepid army of geological and mining workers, of 
whose publications he has made full use, he begs to make every acknow- 
ledgment, and to the Agent-General in London for New Zealand (Mr. 
W. B. Perceval), he desires to return his most cordial thanks for informa- 
tion courteously and freely rendered. 



APPENDIX A. 
Examinations fob Mine Makagebs* Certificates under "The Coal 

Mines Act, 1891," of New Zealand. 
The examinations last four days, and there were in 1892 ninety-one written 
questions, as well as an oral examination on the provisions of the Act. The 
following are examples of the questions : — 

(1) Describe your operations in detail in sinking through the following strata: 
Surface clays and gravel, 12 feet ; strong sandstone, 60 feet ; soft clay, 40 feet ; 
strong sandstone, 20 feet ; conglomerate, 40 feet. (This is one of seven questions 
occupying together three hours.) 

(2) How would you work a coal-seam 12 feet thick, with good roof and pave- 
ment lying at 1 in 20 ? Give all dimensions, and state what percentage of coal you 
consider you could win. 

(3) What area would you have supported on timber in working the pillars in a 
6 feet thick seam of hani coal with an ordinary sandstone roof? Explain when 
and how you would draw the props. 

(4) An upcast 20 fathoms deep has a chimney 60 feet high added to it : what 
is the difference in water-gauge and volume of air circulating if 5,000 cubic feet 
was passing at first? 

(5) What is the condition in the character of a coal that renders it liable to 
spontaneous combustion, and what condition of the mine is chiefly instrumental in 
allowing this property in the coal to come into action ? 

(6) Explain the method of using, and give sketch of, the clip yon prefer in endless- 
rope haulage. 

(7) Does the workable coal of New Zealand occur in one or more positions in the 
coal-formation ? 

(8) Give the composition of an average lignite and of a brown coal. What is 
their distinguishing feature from a bituminous coal, apart from caking? 

(9) The candidate must produce a plan showing the style of workings in a 
colliery, with the surface taken up for at least twenty acres in the vicinity of the shaft, 
and the underground workings in different coloured ink. He must describe how be 



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MININO IN NEW ZEALAND. 



79 



woald connect them with the surface in the event of there being only one 
shaft. The levels and main heading must have assumed traverse calculated in 
detail, and showing latitude and departure for each bearing. 

(10) 10 degs., 200 links ; 4 degs., 700 links ; S degs., 200 links ; all rising at an 
angle of 80 degs.; thence a drive runs 186 degs., 100 links, also rising, and at an 
angle of 10 dega.: what are the vertical and horizontal distances between start and 
finish? 

(11) What is the ^130421 and the ^29791 1 



APPENDIX B. 
As Parts I. and II. of this paper do not bring the exports up to the end of 1891, 
the following table is given as showing the total mineral production of the colony, 
to the latest date available : — 

Table Showing the Quantity and Value op Gold entbbbd fob Expobta- 

TION, AND also THE QUANTITY AND VALUE OP OTHEB MlNEBALH 
PBODUCED, fob THE TEAB 1891, AND ALSO THE TOTAL QUANTITY AND 

Value since Januaby, 1853. 



Name of Ifetal or Mineral 


For the year ending 
December 31st. im. 


^S£Sntes2;\s,"^ 


Quantity. 
Oza. 


. Value. 


Quantity. 


Value. 


PreclouBMetali. 


£ 


Oza. 


£ 


Gold 


251,996 


1,007,488 


12,070,217 


47,433,117 


Silver 


28,023 


5,151 


582,633 


140,148 


Totel Gold and SUver ... 


280,019 


1,012,639 


12,662,860 


47,573,265 


Mineral Prodnoe. indliuSlnx Kauri 
gam. 


Tone. 


£ 


Tone. 


£ 


Copper ore 


^ 


4 


1,394* 


17,866 


Chrome ore 


— 


— 


5,666 


37,367 


Antimony ore 


413 


4,950 


2,786 


41,140 


Manganese ore 


1,163 


2,634 


16,4564 


63,925 


Haematite ore 


A 


1 


52« 


226 


Mixed minerals 


2 


6 


14,068 


69,041 


Coal exported 


91,664 


91,173 


510,364 


506,958 


Coke exported 


2,544 


8,668 


11,486 


17,899 


Coal output of mines in colony 


677,130 


288,565 


6,468,181 


3,234,090 


Kauri-gum 

Total quantity and value of 
minerals 


8,388 


437,056 


148.018^ 


5,831,743 
9,810,266 


681,294^ 


828,047 


7,173,47214 


Value of gold and silver as 
above 

Total value of minerals pro- 
duced, indnding gold and 
silver 




1,012,639 




47,673,265 




1,840,686 




57,383,520 



CORRIGENDA. 
TraM. Fed. lutt., vol. iv., page 81, line 13, for " check " read " cause.*' 



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80 DISCUSSION — MINING IN NEW ZEALAND. 

Mr. T. E. FoRSTBB said he had had the pleasure of seeing one of the 
New Zealand coal-mines, by the assistance of Mr. Binns, who was kind 
enough when he (Mr. Forster) was in Dunedin to show him the Kaitangata 
colliery mentioned in the paper. He was interested by the ingenious 
way in which the manager had contrived to overcome many of the 
difficulties. He would like to ask Mr. Binns whether all the coal on the 
West Coast was capable of being made into coke. He gathered from the 
paper that the proposal to supply New Zealand coke to Broken Hill had 
not been a success ; if the coal was so free from ash^ as stated, it 
seemed strange that it had not been able to compete with English coke. 
Mr. Binns showed how the Colonial Government took over and resumed 
land for the purpose of colliery-railways or mining-works. The law was 
practically the same in Australia so far as railways were concerned, but it 
most be remembered that the physical characteristics of the country are 
very different from those existing at home. Everything which gave 
empbyment in Australia was considered as a matter of public utility, but 
that standard of excellence had not been yet attained in this country. 

Prof. Hull said Mr. Binns' paper seemed to contain a most valuable 
synopsis of the coal-fields of New Zealand, in which the writer had gathered 
into a very small space a large amount of useful information. It was a 
remarkable fact, notwithstanding the proximity of the two countries, that 
the coal-fields of New Zealand should be geologically of much more recent 
date than those of Australia. The great coal-bearing tracts of Australia 
were either of the same Carboniferous age as the coal-fields of the British 
islands, or very nearly verging thereon, but those in New Zealand were 
very much more recent, being of the period on the borderland between 
the Secondary and Tertiary rocks, consequently they could not expect the 
coals to be so highly mineralized as they were in Australia, in the British 
Isles, or in America. He would not have considered the Westport coal 
to be a good steam coal, and it was remarkable that it should have given 
such excellent results as were indicated on page 45. He was going to 
ventui'e on a generalization which he hoped might not be considered 
out of place. It was to the effect that wherever the Anglo-Saxon 
race had colonized, whether in America, in Australia, or in New Zealand, 
that race always seemed to find at hand the materials necessary for the 
development of its industries to the highest degree. These coal-fields in 
New Zealand might have lain for incalculable ages useless in the hands of 
the Maoris, for many years would have passed before they would have 
developed a steam-engine or sunk a shaft. 



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MINING IN NEW ZEALAND. 81 

The President moved a vote of thanks to Mr. Biniis for his 
excellent paper, which was an exceedingly valuable contribution to the 
Transactions^ and, he thought, would form a useful work of reference in 
connexion with the working of mines in New Zealand. 

Mr. T. E. Forster seconded the motion, which was cordially adopted. 

Mr. BiNNS said he was exceedingly obliged to the President for pro- 
posing, and to the members for carrying, the vote of thanks. He thought 
it a sufficient privilege to be allowed to publish what little he knew in the 
Transactions of the Institution, without being specially thanked for it. 
The West Coast coal made very good coke, but the freedom from ash was 
not always the same as in the Westport. Greymouth coal contained from 
8'81 to 6'45 per cent, of ash, and that seam was made into coke to a large 
extent, but it did not appear, from the recent report of the Minister of 
Mines, to have been a success. 



Mr. G. E. Collins read the following paper by Mr. Arthur L. Collins 
on "Fire-setting : The Art of Mining by Fire ": — 



VOL. v.— ifioa^. 



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82 FIBB-SBTTING : THE ART OF linriKO BY FIRB. 



FIEE-SETTING: THE ART OF MINING BY FIRE. 



By ARTHUR L. COLLINS. 



In olden times, before the invention or common use of explosives, the 
best method available for mining through the hardest kind of rock, snch 
as resisted the use of hammer and wedge, was by means of fire. It is true 
that other methods were probably known ; thus there is reason to believe 
that the Egyptians possessed tools capable of boring holes into the hardest 
rocks,* and commonly split off huge blocks by driving wedges into a series 
of such holes, just as granite is often split by plug-and-feather at the 
present day. It is also possible that the northern nations were able to break 
rocks by allowing water to freeze in similar tightly-plugged holes, but 
each of these processes would be more applicable to quarrying than to real 
mining underground. The ancients generally seem to have avoided 
working in the hardest rocks : thus the extensive rock-cut temples and 
tombs of Syria, Egypt, and India are mostly excavated in soft sandstone 
or limestone — they seem indeed often to be merely natural caverns, 
enlarged and chiselled by man. Where masses of exceptionally hard rock 
were met with, work was either suspended or the ground loosened by 
previous heating. 

Nothing is more natural than that the effect of fire on rocks should 
have been known at a very early period ; no one who has lighted a fire on 
rock can help noticing the rending effect of the heat. The same thing 
would be seen after any natural forest fire ; several examples on a very 
extensive scale have recently come under the writer's notice in Australia, 
where bush fires of great extent are frequent, and all the rock cropping out 
at the surface is seen to be cracked and split over great areas. Similar 
forest fires were supposed to have led to the discovery, by some Phoenician 
sailors, of silver in the Pyrenees, according to Diodorus.t 

The fire-setting process seems to have been known to the JewsJ and 
to the Greeks; while Diodorus describes its use in the gold-mines of 
Arabia and Ethiopia, where gold seems to have occurred in white shining 
veins of quartz, glistening with all sorts of other bright metals. He says : 
" The earth which is hardest and full of gold they soften by putting fire 

• The coffer in the Great Pyramid shows marks of jewel-tipped boring-tools, 
according to Mr. Flinders Petrie. 

f Diodoras Sicalus, book t., chap, ii., page 320 of Booth's translation. See 
also LacretiuB, Creech's translation, vol. ii., page 572. 

I Jeremiah, chap, xziii., verse 29. 



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FIBS-SJBTTINa: THE ABT OF ULISXNQ BY FIBB. 88 

under it, and then work it out with their hands.''* In describing the gold 
mines in Spain^ Pliny says : " In mining either by shaft or by gallery 
barriers of sUex are met with, which have to be driven asunder by the aid 
of fire and vinegar .... which method fills the galleries with suffocating 
vapours and smoke."t According to Pliny, vinegar poured upon the 
heated rocks in considerable quantities has the effect of splitting them, 
when the action of fire alone has been unable to produce any effect ; j: and 
according to Livy, Hannibal appears to have used a similar method for 
removing rocks during his passage of the Alps. This use of vinegar does 
not seem to have been tried in later times, although water has often been 
used to suddenly cool the heated rock. 

For many centuries after the breaking up of the Boman power, mining 
seems to have fallen to a very low ebb throughout Europe ; but already in 
the eleventh century it appears that mines of argentiferous galena were 
re-opened in Sardinia by the Pisans, and shafts sunk to a depth of 600 feet 
by fire-setting ;§ and as early as 1359 it was used in Germany on the 
fiammelsberg ; | indeed, it seems to have been the usual mining process 
for very hard rock during the Middle Ages. Agricola, writing in the 
sixteenth century, gives a complete explanation of the method then in use, 
with rude drawings illustrating the process.! According to Serlo, its use 
was retained at Mansfeld up to 1721, and at the Rammelsberg mines up 
to 1878, about 250 years after the introduction of powder for blasting 
purposes ; for, as will presently be shown, it was not because of the superior 
efficiency of powder that the fire-setting method was discontinued, but 
lather because of the increasing cost of firewood and labour, and a growing 
regard for the health of the workpeople. 

It does not appear that the process was ever much used in Cornwall ; 
it is not mentioned by either Carew or Pryce, although T. Tonkin, who 
added notes to an edition of the former writer in 1783, says: " When they 
meet with rocks and very hard ground, .... with such as require not 
only three weeks but three months to hew so many feet through the same, 
they formerly burnt furze and faggots, etc., to break the rocks ; but that 
proving insufficient, and very often fatal to the workmen by the sudden 
change of wind, which drove down the smoke upon them and suffocated 
them, they of late had recourse to gunpowder."** All the earliest workings 
in Cornwall seem to have been stream works, or open cuttings on the 

♦ Diodoras Siculug, book iii., chap, i., page 158 of Booth's translation. f ^^^^7j 
Natural History, book xziii., chap. ^. of Bostock and Riley's translation. 
X Ihid.j book xxiii., chap, xxvii. § Karsten, Sygtem der Metallurgies Berlin, 
1831. g Serlo, Leitfaden zur Berghauliunde, 1884, page 326. ^ Georgii Agri- 
cola, De Re Metallica, Basileae, 1567, page 80 ; and the same writer's Bergwerch 
Bach, 1621. • ♦ R. Hunt, British Mining, page 67. 



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84 FIRB-SBTTING : THE AfiT OP MINING BY FIRB. 

backs of the lodes, which are generally fairly soft in their richest parts ; 
90 that fire-setting would have been unnecessary. In later times, when 
deep mining became more frequent, the increasing scarcity of suitable 
timber would have prevented any wide use of the method; for the forests 
which had originally covered the country were almost entirely destroyed 
to supply the various tin-smelting works, as lamented by Pryce, in 1778.* 
There is however much evidence of fire-setting having been largely 
used in other parts of the British Isles. Thus Hunt quotes from Mr. 
Weston, of Machynlleth (1858), who had opened up an ancient shaft 
about 50 feet deep, where an iron pick and other tools, supposed to be 
Roman, were found, " We find at the bottom of our work much burnt 
wood, and it is evident they had recourse to fire as an agent — ^whether to 
soften the rock, or to heat it for the purpose of throwing water on it to 
crack it, I am not skilled to say, but that fire was used is certain."t 
Again, on page 166, Hunt quotes a paper by Mr. John Taylor, in the 
IVansacti^ns of the Oeological Society of Duhlin^ from which it appears 
that when the Milltown lead mine in Clare was re-opened, they found, 
besides wooden and iron tools, " the remains of fires which had evidently 
been made use of to crack and loosen the masses of calcareous spar and 
carbonate of lime, in which the ore of this mine is chiefly embedded." 
The Cumberland miners, in 1282, claimed a right to take any wood near 
their mines, and to use it for burning, dispersing, and smelting.J An 
ancient charter illustrating the mode of working in the Mendips (about 
1 480) gives a rude attempt at representing fire-setting, with " This is a 
fire" written under it ; and clause lOof the charter itself ("The Lawes of ye 
Myne deeps ") provides for the burial of the bodies of men killed under- 
ground by accident, or by stifling with fire. § The old laws regulating mining 
in Derbyshire, dating from 1601, provide that fires may only be set in a rake 
or vein after working hours (4 p.m.), and that due notice must be given to 
neighbours ; also that when two veins are divided by a thin parting, which 
may be mined by firing (t.^., fire-setting) at one side only, they shall be 
workable by one miner ; || thus clearly showing that the process was in 
common use. The mode of working the narrow Derbyshire veins is clearly 
explained in Farey's Derbyshire (1811). "Previous to the use of gun- 
powder in mining, fires of dry wood were made against the forefield of the 

vein, which, owing to the heat, loosened and slappeted off By 

means of these fires it is surprising to see what narrow veins, mere * serins,' 
the old men contrived to work for great distances into the rock, using 

• W. Pryce, Mineralogiu Cornuhiensis^ book v., chap, iii., page 281. f ^' Hunt, 
British Mining^ page 40. % Tbid.^ page 148. § Ihid.^ pages 134 and 137. 
II J. Mander, Derbyshire yfiner's Glossary ^ 1824, pages 100 and 129. 



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FIRB-SKTTIKG : THE ART OF MINING BY FIRE. 85 

long-handled rakes or hoes to draw out the loosened ore and spar."* 
Altogether, Hunt seems himself to supply ample evidence to refute his 
own conclusion (page 568) that " it is only under the most peculiar cases 
that it (i>., the application of fire) is ever used." 

Fire-setting has also been employed by the Indians of New Mexico 
from time immemorial in the mining of turquoises at Los Cerillos,t and 
other places in America ; and according to Prof. H. S. Munroe, it is still 
used very largely for driving long tunnels in Japan.J 

Many of the old iron-mines of Sweden and Norway were once largely 
worked by the fire-setting process ; the rocks being generally extremely 
hard and fairly dry, and firewood being very abundant. These mines can 
generally be easily identified, by the absence of boreholes, the frequency 
of rounded or conchoidal cavities in the roof where the flame has played 
fiercely upon it ; and, more characteristically still, by the waste-heaps or 
" burrows " being composed of thin flakes of split-off rock, sometimes as 
much as a square foot in area, with a thickness of less than an inch. 
During the past summer the writer had occasion to visit some of the 
old iron-mines near Arendal, in Norway, where the three processes of 
fire-setting, blasting with powder in large holes, and with dynamite in 
small holes, have been successively in use ; and the difference in general 
appearance of the levels and waste-heaps would be obvious to the most 
casual observer. 

The use of fire-setting has not been by any means confined to the 
sinking of shafts and the drivage of levels : it is even better adapted for 
working stopes and rises, from the better upward action of the flames, 
and the absence of water. Cancrinus, writing in 1767, says that at 
Rammelsberg, when the walls of the vein were strong, most of the ore 
was stoped by fire-setting, and gives an illustration showing how the 
" deads " were built up, and wood placed on the top, just under the 
ground to be stoped, so that the fire could act with the best effect ;§ and 
Gallon reproduces an old figure from Delius, showing that lengths of 40 
yards or more of stope were lit up and attacked by fire at one operation.! 
When working on this scale, the wood would naturally be fired at the end 
of the week, so as to be burnt out when the miners were ready to begin 
the next week's work. It is possible that the origin of the modem 
method of "overhand stoping" — so early developed in Germany — is 

• R. Hunt, British Mining^ page 144. f Report of the United States Census 
Office^ Joum, Soc, Arts, vol. xxxix., page 821. % H. S. Drinker, Blasting, etc., 

New York, 1883. § Franz Ludwig Cancrinus, Besrhreibvng der Bergwerhe, 

Frankfurt, 1767, page 95, et seq. || Gallon, Mining, translated by Messrs. Foster 
and Galloway, vol. i., page 176, also figs. 121 and 122. 



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86 FIRE-SETTING: THE AET OF MINING BY FIRE. 

traceable to this extensive use of fire-setting in overhead stopes, by the 
old German miners. 

The great trouble with fire-setting seems always to have been the heat 
and smoke produced — the latter being often strongly sulphurous, where 
the ore contained pyrites or other sulphides. Nearly all the old writers 
mention this trouble : thus Lohneyss says that " the miners suffered 
terribly from the fumes ; and that at the St. Georg mines the heat was 
BO great that melted silver is said to h^ve flowed from the working- 
faces,"* and other instances have already been mentioned. It is easy to 
see that this would have been a great obstacle, when the means of 
artificial ventilation were so imperfectly understood ; but it applies far 
less at the present day. Indeed, by a proper system of ventilation with 
upcast and downcast shafts, it need be no more objectionable than the 
ventilating-f umaces still used in some collieries ; and at Kongsberg silver- 
mine in Norway, the system is still used occasionally for driving levels, 
mainly on account of the great improvement in ventilation which it 
causes throughout the mine. 

The writer has recently had an opportunity of seeing the process at 
work in the Kongsberg mine, and as it is perhaps the only place of import- 
ance in Europe where it still survives, a few details of the mode of working 
may be of interest. 

The process is now confined to the occasional drivage of levels in hard 
siliceous gneiss — ^it having been found that the mica-schist and other 
micaceous rocks, which also occur at Kongsberg, are far less favourable 
for fire-setting. A short piece of level is driven at first in the ordinary 
manner, to get room to start the process; and wood — mainly logs of 
white fir and red pine, dry and split — is closely piled up so that the fire 
plays against the " face ; " waste wood or old timbers from the mine 
being often piled against the freer-burning fir, to concentrate the heat. 
When the pile is lit, smoke fills the level, and the men leave it, but in 
two or three hours it is generally burnt out, and as soon as the men can 
come in, the broken stone which has split off is cleared away, and all that 
is suflBiciently loose is broken down. The fire sets stronger on the roof 
and sides than on the sole, so that the levels have a constant tendency to 
slope upwards. This can partly be prevented by better arrangement of 
the fuel, putting long pieces at the bottom and covering the upper part ; 
but sometimes the sole has to be blasted. The ordinary speed of driving 
is from 5 feet to 20 feet per month. 

Prof. Hellandf states that fire-setting kept its place as the common 

• Lohneyss, Beri^ht torn Bergwerck (1617). 

t A. Helland, Orubedrift, Kristiania, vol i., page 86. 



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FIRE-SETTING: THE ART OF MINING BY FIRE. 87 

method at Eongsberg so long as double-handed boring, iron borers, and 
powder were used ; but that on the introduction of single-handed boring, 
steel borers, and dynamite or other high explosives, the use of the old 
method rapidly died out. He gives the following figures, showing the 
relative cost of driving a level 6 feet 6 inches high by 5 feet wide, for 
each fathom of length : — 

DUBINQ 1860-1864, WITH POWDBH. 

Wagen per Man 
Da/awork. Materlala. Smithing. Wages. TotaL per Shift. 

£b. d. B.d. £s.d. £ B. ± B.d. 

Hand-boring 47^ 18 6 10 2 7 12 6 9 11 1 3 
Fire-8etting . 34J 4 3 4 — 3 7 7 10 4 1 lOJ 

DuBiNQ 1881-1885, WITH Dynamite. 
Hand-boring 16^ 2 8 6 1 3 9 1 5 15 10 4 4) 

Fire-setting 38| 3 17 2| — 4 6 4 8 2 6) 2 4 

It will be seen that in 1864, fire-setting was both cheaper and quicker 
than the old method of blasting with powder in large holes ; but on the 
introduction of dynamite and small holes, things were entirely reversed ; 
not only did the new method effect a great saving in time and cost, but 
fire-setting became actually dearer than before, owing to the increasing 
wages. It should be added that at Eongsberg suitable wood is very 
cheap — an important point, when it is remembered that about 9 parts 
(by volume) of wood are required for 1 part of rock, and that much less 
skilled labour is employed for the fire-setting — as is indeed shown by the 
rate of wages paid. There seems to be little reason to believe that fire- 
setting is very unhealthy for the men employed, when care is taken to 
ensure efficient ventilation. No doubt the great heat developed is 
prejudicial ; but perhaps not more so than the dynamite smoke, the 
constant jar to the system in beating the drill, and the fine sharp dust 
often inhaled, incidental to the more modern process. 

Attempts have been made at various times to improve the fire-setting 
method^ by using turf at the Rammelsberg mines in the Harz, and 
brown coal in the tin stockwerks at Altenberg ; but neither were 
successful. Better results were obtained with coke at the St. Christoph 
mine near Breitenbrunn in Saxony.* At Felsobanya in Hungary, the 
method is improved by the firewood being held in an iron framework on 
1^ or wheels (" pregelkatze "), which concentrates the fire and improves 
the draught. 

According to Serlo, Hugon has used a small furnace, mounted on 
wheels, supplied with a blast to urge the flame direct on to the rock, at 
the Challanges mine in France. Burning small coals, this apparatus in 

* Serlo, Berghaukunde, page 326. 



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88 DISCUSSION — FIRE-SETTING : THE ART OP MINING BY FIRE. 

65 hours drove an end 4 feet wide and 6 feefc high a distance of 5 feet ; 
whilst two men with the usual explosives would only drive the same end 
from 5 feet to 6^ feet in a month. If this were done at a reasonable cost, 
it would be a very fine result, but as to relative economy Serlo gives no 
particulars. 

As to the possible future of the fire-setting method, it is unlikely that 
it will ever again come into use to any important extent ; for, although it 
could hold its own under suitable conditions against blasting with 
powder, yet the modem improvement in high explosives and boring 
machinery, which have deprived mining through the hardest rock of all 
its terrors, have done away with any necessity for the old process. In 
exceptional cases, however, where machinery and skilled labour are not 
available, where fuel is cheap, and the rock very hard and siliceous — condi- 
tions which occasionally confront the mining engineer in semi-civilized 
countries — it would be worth while to reconsider its many advantages. 
By making proper arrangements, the ventilation of the workings need give 
no serious trouble, while the ore extracted would be more or less thoroughly 
roasted — an important gain in most smelting operations, or where the ore 
has to be subsequently crushed ; and with tin or gold ores, the destruction 
of the pyrites and other sulphide minerals would render the subsequent 
dressing more easy and perfect. Indeed, in the case of refractory gold ores, 
the advantages of a preliminary roasting, in making more of the gold free- 
milling, would often compensate for a good deal of extra expense in 
mining underground ; it is certain that the early gold-miners were quite 
alive to the advantages of roasting gold ores before crushing, and it is 
possible that in many cases a return to the ancient practice would be 
attended by great benefit. 

It has been suggested* that fire-setting might be profitably used to 
enlarge a tunnel in hard rock, where a " bottom heading " had already 
been driven along the sole. But here the weakening of the roof and 
sides, owing to the great heat, would probably tell strongly against the 
method. It is also possible that where w^aste fuel is cheap, or where 
natural gas is available, the gas blow-pipe, urged by an air-blast, might 
prove of service. Such a jet would produce a very intense heat, which 
could be very precisely directed ; but the idea does not seem ever to have 
been tried in practice. 



Dr. C. Le Neve Foster (Llandudno) wrote that Mr. A. L. Collins' 
paper would ser\'e to remind miners of the present day that the almost 

* H. S. Drinker, Blasting, etc. New York, 1883. 



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DISCUSSION— FIRE-SETTING : THE ART OF MINJKG BY FIRK. 89 

forgotten process of fire-setting had done great service in its time. He 
might have added that it was still in use in Burmah for quarrying jade, and 
in some parts of India for quarrying building-stone, as well as in Korea 
for gold-mining. With reference to the supposed use of vinegar, had not 
some one suggested that the Latin word was wrongly transcribed or 
wrongly translated, and that the true meaning was " axe " or " pick-axe ? " 
In Italian nowadays the word "accetta" was used for axe. When he 
(Dr. Foster) visited the Kongsberg mine in 1875, he found that ample pro- 
vision was made for carrying away the smoke, so that it was only the very 
end of the level which was filled with fumes. In one case, a large oval iron 
pipe (2 feet by 1^ feet) was put in near the roof, and the smoke was led 
away to a separate compartment of the shaft, partitioned off by a brick 
wall. In another instance, a channel for the smoke was made by building 
an arch near the roof of the level. He (Dr. Foster) must confess that he 
was somewhat sceptical about the advantages of fire-setting as furnishing 
a preliminary roasting of the ore, as suggested by Mr. Collins, who over- 
rates the amount of oxidizing action which would take place ; the fragments 
of ore might occasionally become glazed over, in which case the process 
would be the reverse of beneficial if amalgamation had to follow. It might 
be interesting to point out, in conclusion, that fire was used by prospectors 
in Siberia for sinking shafts through frozen gravel in order to reach gold- 
bearing alluvia. 

Mr. Bennett H. Brough (London) wrote that the subject of fire- 
setting was a particularly fascinating one, even to the dullest mining 
student. This was evident in a Science and Art Department examination- 
paper which he remembered having an opportunity of seeing some years 
ago. At that time, attention was being directed to the use of lime-cart- 
ridges in collieries, and the question the examiner asked was : " What 
methods are employed for breaking down coal when blasting cannot be 
applied?" To this a candidate replied that no method would be 
found better than the ancient method of fire-setting, in which large fires 
were lit against the surface of the coal, causing it to split in all direc- 
tions. History does not relate whether this candidate subsequently 
obtained a manager's certificate. In order to see the process of fire- 
setting in operation, some years ago he (Mr. Brough) visited the 
Kongsberg mines in Norway, the Rammelsberg mine in the Hartz, and 
some of the Hungarian mines. Only in the first was he successful, and 
he could confirm the accuracy of Mr. Collins' description. In the paper 
there was one omission from the very full bibliographical notes, that is, a 
reference to a complete account of "this good and antient way of 



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90 DISCUSSION — FIRB-SETTING : THE ABT OF MINING BY FIBB. 

workmanship" in that very scarce work, A Miner* 8 Dictionary ^ written 
by William Hooson, a Derbyshire miner (Wrexham, 1747). Cnriously 
enough, the process of fire-setting stDl survived, according to R. Hehn- 
hacker, in Siberia, where it was used in alluvial gold-mining in combination 
with a sort of natural Poetsch process for sinking shafts in the watery 
strata. These shafts are sunk by the aid of fire in winter when the 
ground is frozen to a considerable depth, the wall of ice serving to support 
the excavation. 

Mr. SouTHEBN asked if Mr. Collins could give any instances as to 
how far heat would penetrate into rocks ? Of course he could see that it 
would vary according to the nature of the rock and the intensity of the 
fire. 

The Pbbsibent thought the thanks of the meeting were due to 
Mr. Collins, for he had evidently worked up the subject, and gave them 
an insight into the ancient methods adopted. He had pleasure in pro- 
posing a vote of thanks to Mr. Collins for his interesting and valuable 
paper. 

Mr. Southern seconded the vote, and said the paper treated the 
subject in a most exhaustive manner. 

Mr. G. E. Collins said he was sure his brother would be gratified to 
hear of the vote of thanks accorded to him. He was afraid he could not 
answer Mr. Southem^s question, nor did he think it was a matter of 
much importance, as the farther the heat went into the stone the less 
advantage it was. They wanted the heat to be at the surface, if the 
sudden cooling was to crack it off. It was impossible for a paper of this 
kind to include all the regions in which fire-setting had been used, and 
Dr. Foster had been able to add others. In a recent part of the 
TransactianSy fire-setting was mentioned in regard to gold-mining in 
Brazil,* and he heard from his brother that there were extensive traces 
of its use in the Hindu Kush. The process was illustrated in nature 
by the scaling which took place in rocks subjected to sudden variations of 
temperature, and in some instances this was a very important factor in 
atmospheric denudation. 

Mr. M. Walton Bbown wrote, that in the Deccan, the process of stone 
burning was performed by a tribe called stone Waddahs, who are very 
skilful at it. They light fires of brushwood over the flat or convex surface 
of the nearly horizontal rock that crops up everywhere around, and a flake 
of varying thickness begins to crack off very soon. They follow the 
progress of the crack by listening to the sound arising when they tap the 

• Vol. iT., page 220. 



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DISCUSSION — FIBE-SBTTINa : THE ABT OF MINING BY FIRE. 



91 



sorfaoe wiiJi a stone, and keep moving their fires backwards along the 
sorface as the crack develops. With a good class of gneiss stone like that 
found at the Satnapilli quarries they can get out slabs of 10 or 12 feet by 
4 or 5 feet by a foot thick ; but the usual size for coursed rubble masonry 
is about 2^ feet by 1^ feet by | foot, only of course not in so regular a 
shape as a parallelogram. Much of the stone used is only 4 inches thick. 
It comes out beautifully parallel and flat-bedded. A large stone burning 
business, say three or four train loads per day, requires a very extensive 
hmdohust in carts for fetching in brushwood from all over the country. 
The quarries, too, are widely scattered, places the size of a dinner table or 
as large as a moderate room, scattered perhaps in scores over 40 or 50 
square miles of country. Until taught how to do it, by the aid of 
imported Waddahs, the natives of the Eistna District had never heard of 
stone burning ; and the very numerous and extensive remains of ancient 
religious dynasties which are to be found freely scattered about the country 
show the whole of their stone to have been either dressed boulders, or 
extracted from the quarry by the slow process of wedging. The thickness of 
the stone to be burnt out by the Waddah burners is not wholly a matter of 
luck. They can begin at any desired thickness by wedging a small crack 
at the desired depth, and this keeps cracking off fairly parallel, with, 
usually, a tendency to thin off somewhat. It is difScult to bum a good 
thick stone off the rock table in very hot weather. The cracking appar- 
ently depends on the destructive stress engendered at the plane where the 
heat of the fire finds itself unable to penetrate further, and where the 
difference of expansion of neighbouring layers is greatest. In the cold 
winter mornings and during the rains the result is more satisfactory. 
The quarries are all of gneiss stone, and the following are the results of 
experiments made by Prof. Unwin : — 



DoMrfpUon of Stone. 


Onuhinc Load per 
Square Inch. 


Weight per 
OttbicFoot. 




Minimum. 


KondapiUi, wedged 
„ burnt 

Satnapilli, burnt 

Eammamet, burnt 


Tons. 
9-580 
13-400 
9-210 
7-240 


Tons. 
9-480 
6-471 
7-470 
4-680 


Lb0. 
196 
165 
166 

178 



The gneiss is susceptible of fine dressing and takes a superior polish. 
The Kondapilli stone is got out in rougher beds than the Satnipilli burnt 



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92 DISCUSSION — FIBB-SBTTING : THE ART OF MINING BY FIRE. 

stone. The light grey Santapilli gneiss weighs about 165 pounds per 
cubic foot. It may usually be expected to crush under a load of 8 to 9 
tons per square inch. The darker burnable Kondapilli stone was only 
crushed at 13*4 tons per square inch in an unexceptionally good specimen. 
The hard unbumable Kondapilli stone, which was wedged, is of much 
greater weight, and its resistance to crushing is much higher.* 



Mr. H. D. Hoskold's "Notes upon a Practical Method of Ascertaining 
the Value or Price to be paid for Zinc Mineral " was taken as read. 



* Indian Engineering, yoI. ziii., page 473. 



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VALUE OP ZING-OBBS. 93 



NOTES UPON A PRACTICAL METHOD OP ASCERTAINING 
THE VALUE OR PRICE TO BE PAID FOR ZINC 
MINERAL. 

By H. D. HOSKOLD. 

The objecfc of this brief paper is not to give a history of zinc-mining 
as carried on in various parts of the world, the amount of produce, metal- 
lurgical processes, or the geology of the rocks in which this class of 
mineral occurs, but merely to indicate and to place on record the practical 
methods followed in ascertaining the value or price which may be paid 
for zinc mineral. 

When in Spain some years ago, the writer had an opportunity of 
thoroughly investigating the question and analysing the various formula 
used by the different purchasers of zinc mineral, and in order to facilitate 
such determinations of price as were of constant occurrence, he devised 
various rules, and also produced a series of tables based upon the EngUsh 
formula, indicating at a glance whether any or what price could be paid 
for zinc mineral to yield a profit under certain given conditions. 

It is not to be understood that anything new or novel will be intro- 
duced ; still it has occurred to the writer that what he found to be of great 
service to himself may also prove of some value to those who may have 
occasion to study the question of zinc-mining for commercial purposes. 

When it has been determined that a sufficient quantity of calamine or 
blende mineral exists to justify a regular exploitation, some of the more 
important considerations will involve the question of cost of production and 
the assay percentage of the mineral. If it should be necessary to inspect 
mines situated in isolated parts of Spain, India, North America, Canada, 
etc., an inspection occupying a considerable period of time, and at a con- 
siderable distance from centres of population and civilization, it would be 
convenient to carry a few simple chemical implements in order to practise 
any assays which may be necessary, according to the Schaffner process 
by the humid way, using a solution of sulphide of sodium as a reagent 
in determining the assay percentage of zinc ; and also oxide of iron, as 
an indicator to ascertain when the process is concluded, or when all the 
zinc has been precipitated. It is unnecessary to give the full details of 
this process, but the writer has found in practice that the most convenient 
strength for a sulphide of sodium solution is about 70 cubic centimetres to 
0*5 gramme of zinc. It is also interesting to note that if iron oxide be 



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94 VALUE OF ZIKO-OBES. 

snflpended in pure distilled water, about 0*6 cubic centimetre of sulphide of 
sodium solution will be required for every 100 cubic centimetres of water 
to colour the iron black ; therefore 0*6 cubic centimeti-e for every 100 
of sodium solution is deducted from the total number of cubic centimetres 
of sulphide of sodium used in the assay operation. 

The Vieille Montague Company produces a very considerable quantity 
of zinc mineral from its mines situated in the Picos de Europa, Spain, 
and the formula adopted in determining the price to be paid to other 
zinc-mineral producers is as follows: — 

V = (R-E)(P-T) + ^^^:^^, 
in which 

V = the value of a ton of mineral. 

R =s percentage of the mineral per volumetric assay. 

E = discount of the anterior percentage for the loss which takes 
place in the treatment of the mineral in the furnace, which 
is 11 per cent, in the crude mineral, 15 in the calcined, and 
17 when the quantity of silicate exceeds 15 per cent. 

P = price of 1 kilogramme of zinc when the current price is 45 
francs per 100 kilogrammes. 

T = expense of the metallurgical treatment per ton of mineral, 
which is fixed at 80 francs. 

D = difference between the price of 45 francs per 100 kilogrammes 
of zinc which we have supposed and the value which it has 
when the calculation is made, with the understanding that 
the value of 1 kilogramme has always to be taken. 

A second formula, employed by the intermediate agents or Antwerp 
buyers, is as follows : — 

V = ^ "" S (P - 2-50) - 60, 
\ 10 / 
and is thus practically illustrated : — 

Supposing that the price of spelter in London is, say, £18 per ton, 
and the exchange at the rate of 25'20 francs. 

Francs. 

Then £18 x 35-20 - 45360 

Less I'o per cent, to redace ton of 1,015 kilos to 1,000 kilos - 6*80 



Per 1,000 kilogrammes - 44680 

Per 100 „ - 44-68 

Less 2*50 francs >- 2*60 

Per 100 kilos - 42*18 



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YALITE OF ZIKO-OBES. 95 

SappoBing the ore to contain 50 per cent., this, less \j aocording to 
the formula, would leave : — 

Fnunot. 
4096 X 42-18 francs .-« „ 

10 -168 72 

Deduct cost of smelting — 60-00 

Value of 1,000 kilogrammes of ore— cost, insurance, and ) ^ io8-72 
freight — delivered ex ship Antwerp J * 

The following formula is also employed on the Continent by agents 
purchasing zinc ores : — 

V =(^m^) (P - 5 ^) « 65 francs. 

In order to obtain a profit from the sellers and also from the smelters 
of zinc mineral, the intermediate purchasing agents have the practice of 
varying some of the elements constituting the formulae, but it is obvious 
that the best price would be obtained when the mining producers sell 
their crude mineral direct to the smelters. 

When blende ores contain less than 5 per cent, of lead the smelter's 
charge is raised from 65 to 85 francs per ton for, as it is termed, ^' return 
charges " for the reduction. 

The principal purchasers of zinc mineral in Swansea employ the 
following rule in estimating the price which may be paid per ton for 
such ores: — 

Rule — From 100 deduct the calcination-loss and divide the assay, 
less 1 unity, by the result. From the answer deduct i + 1. Multiply 
the remainder by the London quotation price for spelter per ton, less 
£1, and divide by 160. Deduct return charges for smelting, or £2 10s., 
also deduct calcination-percentage or loss value, and also 5s. per ton, cost 
of calcination. 

Thus, supposing calamine ore would assay, say 40 per cent, with a 
calcination-loss of say 80 per cent., spelter being at the rate of £17 per 
ton in London, we should have:— 

100-30- 70%; and 40-1 -39%; 
Also —^ - 66-7 % ; then 56-7 - i = 44-6 - 1 - .43-6 %. 
. , 43-6 X £16 

^°^ 100 

Less letum charges 

Calcination loss at 80 % of £4.9s. 6dl 

Deduct cost of calcination per ton 

Total value or price per ton of crude calamine, ew ) « a2 17 8 
ship at Swansea, dry weight j - *^ i' 



£6 19 
2 10 


6 




4 9 
1 6 


6 
10 


3 2 
5 


8 




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96 VALUE OP ZINC-OEBS. 

Taking the preceding assay and loss due to calcination, and if it 
were required to determine the total weight of calamine necessary to 
make up one ton of calcined ore at the rate of 57'1428 per cent., 
we should have: — 

20X100 OOK-I.! 

— — — = 28-5714 cwts. 
The proof of the percentage of the calcined mineral is: — 

40 X 100 r^.,.oo 

— = 67*1428 per cent. 

70 ^ 

The excess of the percentage due to the extra weiglit of 8*5714 cwts. 

of crude mineral would be: — 

57-1428x80 ,„,,,, 

j^g = 17-1428 per cent. 

and 40 ^ + 17-1428 % = 57-1428 ^, as previously indicated. 

If it were required to ascertain what percentage of crude mineral 
would produce 57*1428 per cent, under the above conditions, we should 

also have 

57*1428 X 70 „^ ,^,^^ 

j^^ = 89-99999 per cent, 

or practically 40 per cent, as proposed. 

It may be observed, under the conditions proposed, that 28*5714 
cwts. of crude ore at 40 per cent, would produce 20 cwts. of calcined 
mineral at the rate of 57*1428 per cent.; but the price of 20 cwts. at 40 
per cent., excluding the cost of calcination, is £3 28. 8d. per ton for crude 
mineral, and 28*5714 cwts. at £3 28. 8d. per ton would be worth a gross 
sum of £4 9s. 6jd., and deducting 7s. l^d. for calcination, would leave 
the net price £4 2s. 4|d., but these conditions refer to a sale of the 
mineral in a crude condition. Then the question arises whether the 
difference between the cost of transport of 28*5714 cwts. against 20 cwts. 
of calcined mineral, and the cost of calcination, would be sufficient to 
justify the calcining operation being carried on at, or in the vicinity of 
the mines. Naturally, this would involve a consideration of the facilities 
afforded and the cost of labour and fuel, which may vary under different 
circumstances ; but, supposing that the calcination be carried on by the 
proprietor of the mine in one place and also by the purchaser of the 
mineral in another under similar conditions of cost, the mining proprietor 
would appear to gain nothing by the calcination, but only the difference 
in the cost of transporting 28*5714 cwts. of crude mineral, as against 
20 cwts. of calcined mineral, because there is no more metal in the 
20 cwts. of calcined ore at 57-1428 per cent, than existed in the 28*5714 
cwts. at the rate of 40 per cent. For: — 



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VALUE OP ZINC-ORBS. 97 

£ B. d. £ B, d. 
The groBB selling price of 28*6714 cwts. crude ore 

at 40 per cent, is 4 9 6^ 

Deducting pnrcbaser'g cost for calcination ... 7 1^ 



Price paid for 20 cwts. of calcined mineral yielding 

at the rate of 67-1428 per cent 4 2 4| 

Extra price allowed and paid by purchaser to 
mining proprietor for the calcination of 
28*5714 cwts. of crude ore 7 IJ 



4 2 4f 



Total price paid by the purchaser ... 4 9 6^ 
But the sum of 7s. 1^. has to be expended by the 
mining proprietor for the calcination of the 
mineral — therefore, deducting it 7 IJ 



4 2 4i 

Difference in selling price nil 

proving that under the circumstances the price received in the two cases 
is the same. 

Supposing the freight and insurance on delivery in Swansea is 12s. 9d. 
per ton, the price paid in Spain in 1881, the cost of 28*5714 cwts. of 
erode ore would be 17s. 4id., or a difference in favour of reducing the 
weight by calcination of 4s. 7^i. per ton, so that it would appear that a 
mineral which could not be extracted from a mine, at a profit, if sold in 
the erode condition, may be made to do so if calcined at a cost equal to, 
or not much in excess of, that allowed by the purchaser for the same 
operation. 

Naturally, the mineral should be delivered in a dry condition, but if 
it is otherwise it may be subjected to a reduction for humidity. 

When there are a very large number of assays and resulting calcula- 
tions to be made by the inspecting engineer when examining the mines, 
or at the nearest convenient point to them, it would be advantageous to 
collect all the details as exhibited in the following tabular form. 

The elements contained in columns Nos. 2 and 3 consist of a portion 
of a long series of assays made by the writer when in Spain in 1879. 

The calculated quantities in columns Nos. 4, 5, 6, and 7 respectively 
were determined by the foregoing roles, and were employed in another 
clafls of computations required for the determination of the commercial 
present value of the zinc mines then under consideration. 

VOL. V^l»M». 7 



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98 



TALUB or ZUrC-OBES. 









Calculated Details. 








i 


'^1 

1% 


•8 g 


Weight of Grade 

Ore 

required to 

make up 1 Ton of 

Calcined Ore. 


Weight of Calcined 

Ore 

derived from 

Weight in Column 

No. 4. 


Weight of Metol 

in eTei7 90 Owte. of 

Calcined Ore. 


Total 

of Mt^ 
in the Ore 

after 
Calcination. 


1 

2 
3 
4 
6 
6 
7 
8 
9 
10 


3413 
42-66 
43-20 
46-93 
46-93 
43-20 
43-20 
44-80 
41-60 
50-66 


26-70^ 
30-10^ 
29-78 J 
25 00^ 
31-60^ 
30 9oi 
28 -90 J 
30 -95 J 
28 -75 J 
32-50 J 


Owte. to. Lbfc 
20 
7 2-912 


Owte. Qrfc Lbs. 
14 3 5-600 
5 22-315 


2 1 


Lba. 

5-60 

15-55 


3413 
11-94 


27 2-912 


19 3 27-915 


9 


21 15 


46-07 


20 
7 2-912 


14 3 5-600 
5 22-315 


8 1 
2 3 


16 
22-603 


42 
14-70 


27 2-912 


19 3 27-915 


11 1 


10-503 


56-70 


20 
8 18-816 


14 22-400 
5 3 4-556 


8 
3 2 


18-816 
1-370 


-43 
17-56 


28 18-816 


19 3 26-956 


11 2 


20-186 


60-56 


20 
6 2 18-592 


15 
4 3 27 944 


9 1 
3 


16-800 
14-898 


47 
15-66 


26 2 18-592 


19 3 27-944 


12 2 


3-698 


62-66 


20 
8 3 26-208 


13 3 5 60 
6 22-348 


9 1 
4 


16-80 
24-917 


47 
21 11 


28 3 26 208 


19 3 27-948 


13 2 


13-717 


68-11 


20 
8 3 26-208 


13 3 5-60 
6 22-284 


8 2 
3 3 


11-200 
12-669 


43 
19-31 


28 3 26-208 


19 3 27-884 


12 1 


23-869 


62-31 


20 
8 18-816 


14 22-40 
5 3 5-520 


8 2 
3 2 


11-200 
1-371 


43 
17 56 


28 18-816 


19 3 27-920 


12 


12-571 


60-56 


20 
8 3 25-21 


13 3 5-600 
6 21-595 


9 
4 



4 345 


45 
20-19 


28 3 25-21 


19 3 27-195 


13 


4345 


6519 


20 
7 3 2-912 


14 1 16-800 
5 2 11056 


8 
3 


22-400 
22-074 


41 
16-02 


27 3 2-912 


19 3 27-856 


11 1 


16-474 


57-02 


20 
9 1 17-92 


13 2 11-20 
6 1 16-67 


10 
4 2 



22-96 


60 
23-62 


29 1 17-92 


19 3 27-87 


14 2 


22-96 


73-52 



The following tables are a portion of a series calcalated according to 
the principles laid down in the English formnla, and would be of con- 
siderable service, supposing the conditions are now the same as they were 
when the tables were constructed ; if not they may serve as a model for 
the construction of others when the variable elements employed, such as 
the price of spelter, cost of exploitation and transport have been 
determined. 

Under the conditions of Table No. 1 there would appear to be very 



Digitized by VjOOQ IC 



VALUE OP ZINC-ORES. 99 

little or no profit upon mineral of less than M per cent, with a calcina- 
tion loss of 26 per cent. It wonld, however, be a question for the exploiters 
of a mine to ascertain for themselves whether they would be satisfied with 
a profit to be derived from a less percentage of ore presented under the 
conditions exhibited in the tables from No. 1 to No. 9. 

It was not considered of importance or advantage to introduce the 
remaining series of tables of this class in the possession of the writer. 

When 2dnc mines are situated at a long distance from centres of 
population and railway communication, in elevated places like the Picos 
de Europa and others, in Spain, and the roads are long, tortuous, and 
difficult, the transport of the mineral from such mines to calcining-kilns 
at lower levels, the unloading, reloading after calcination with probably 
extra transport from the kilns to store-houses at the nearest shipping-place, 
becomes very costly. Such expenses are included in the sums which 
form column No. 5 of the tables. 

Taking for example the first table under No. 16, and assuming that 
the cost of extracting the ore is no more than lid. per cwt. Column 3 
with an assay-produce of 49 per cent, of metal and 35 per cent, calcina- 
tion-loss, the total cost of extraction amounts to 18s. 4d. per ton, which 
deducted from £2 4s. in column 5 leaves £1 5s. 8d. per ton, to cover all 
expenses and contingencies due to the transport of the mineral to a place 
of shipment. 

The same conditions would exist whether a zinc-raining proprietor 
were to sell his ore direct to the smelters or foreign purchaser, or to an 
intermediate purchasing agent, with a probable result that he may gain 
more by the former than the latter plan. However, in the latter case, it 
is assumed that a profit would be included in the lid. per cwt. or what- 
ever other price may be agreed upon. If, however, it did not exist, then 
the intermediate purchasing agent's net profit of £1 6s. 6^d. per ton, 
colunm 8, would have to be reduced to suit the circumstances or demand 
of the mining proprietor. 

The calculated net profit of £1 6s. 6jd. per ton proves that it would 
be exceedingly inconvenient and injurious to the original mineral producer 
to allow the intervention of an intermediate purchasing agent, who, in 
such a case would become a speculator on the bounty and possibly 
ignorance of the original miner or ore-producer. 

When small mines are worked with inadequate capital, and only at 
intervals, and the production is very limited, and the owner has no 
personal knowledge of, or confidence in, foreign smelting purchasers, 
small parcels of zinc ore used to be sold to local agents in the manner 
indicated, and doubtless the custom is still continued. 



Digitized by VjOOQ IC 



100 



YALinS OF ZINC-OBBS. 



Caloitlatiovs upon Cbttdb CALAKorB Obb. 

Spelter— £16 in Swansea, £17 in London. Weight to be 112 lbs. per English owt 
Freight and Inanrance, 12s. 9d. per ton. 











Tablb No. 


1. 








Ko. 


oeutage 
of Ore. 


Lo«aby 

Cald' 


Cost per 


ToUl Cost 


ToUlOort 


Gron Value 


NetFtoM 


nation. 


Engliah 
Owt. 


on Board. 


atSwanaea. 


per Ton. 


per Too. 








d. 


£ t. d. 


£ t. 


d. 


£ s. d. 


£ t. d. 


1 


84 


26 


7k 


19 


2 1 


9 


2 14 


♦0 1 71 


2 


85 


26 


7i 


19 


2 1 


9 


2 2 8 


11 


8 


36 


26-5 


7i 


19 


2 1 


9 


2 6 61 


8 8{ 


4 


37 


26 


n 


19 


2 1 


9 


2 8 3f 


6 6i 


6 


88 


27-5 


7i 


19 


2 1 


9 


2 11 If 


9 4i 


6 


89 


28 


7i 


19 


2 1 


9 


2 18 114 


12 24 


7 


40 


286 


7i 


19 


2 1 


9 


2 16 91 


16 0^ 


8 


41 


29 


7i 


19 


2 1 


9 


2 19 74 


17 104 


9 


42 


29 


7i 


19 


2 1 


9 


8 2 24 


1 61 


10 


43 


30 


7^ 


1 10 


2 2 


9 


8 6 84 


1 2 64 


11 


44 


31 


8 


1 12 


2 4 


9 


8 8 44 


1 8 74 


12 


45 


32 


8J 


1 14 


2 6 


9 


3 11 6i 


1 4 84 


13 


46 


33 


9 


1 16 


2 8 


9 


3 14 61 


1 6 91 


14 


47 


33 


n 


1 18 


2 10 


9 


3 17 14 


1 6 41 


15 


48 


35 


lOJ 


2 2 


2 14 


9 


4 81 


1 6 llf 


16 


49 


35 


11 


2 4 


2 16 


9 


4 8 84 


1 6 64 


17 


50 


35 


Hi 


2 6 


2 18 


9 


4 6 114 


1 7 24 


18 


61 


35 


12 


2 8 


8 


9 


4 8 6 


17 8 








1 


Fablr No. 


2. 








1 


34 


26 


7i 


1 10 


2 2 


9 


2 11 


•0 2 7f 


2 


85 


26 


74 


1 10 


2 2 


9 


2 2 8 


♦0 1 


3 


36 


266 


74 


1 10 


2 2 


9 


2 6 5| 


2 8f 


4 


37 


27 


74 


1 10 


2 2 


9 


2 8 8f 


6 6f 


5 


38 


27-6 


74 


1 10 


2 2 


9 


2 11 If 


8 4| 


6 


39 


28 


7i 


1 10 


2 2 


9 


2 18 114 


11 24 


7 


40 


28-6 


74 


1 10 


2 2 


9 


2 16 94 


14 04 


8 


41 


29 


74 


1 10 


2 2 


9 


2 19 74 


16 104 


9 


42 


29 


74 


1 10 


2 2 


9 


8 2 21 


19 64 


10 


43 


30 


7i 


1 11 


2 8 


9 


8 6 3i 


1 1 64 


11 


44 


81 


81 


1 13 


2 6 


9 


3 8 44 


1 2 74 


12 


45 


82 


81 


1 15 


2 7 


9 


8 11 54 


1 8 84 


13 


46 


33 


9i 


1 17 


2 9 


9 


8 14 6f 


1 4 91 


14 


47 


83 


91 


1 19 


2 11 


9 


3 17 14 


1 6 41 


15 


48 


86 


101 


2 3 


2 16 


9 


4 8| 


1 4 111 


16 


49 


35 


11* 


2 6 


2 17 


9 


4 8 3i 


1 6 64 


17 


60 


86 


111 


2 7 


2 19 





4 6 111 


1 6 24 


18 


51 


85 


12i 


2 9 


3 1 


9 


4 8 5 


16 8 



Digitized by VjOOQ IC 



VALUE OF ZINC-OBES. 



101 



CALOUiATioirB UPON Cbitdb Calaminb Obb. — Continued. 

Spelter — ^£16 in Swansea, £17 in London. Weight to be 112 lbs. per English cwt. 
Freight and Insurance, 12b. 9d. per ton. 



Tablb No. 8. 


Ha 


Per- 
oentase 
of Oie. 


Oalol/ 
nation. 


Oortmr 


ToUlOost 


Total Oort 


Orofla Value 


Net Profit 


EogUah 

Cwt. 


on Buard. 


aiSwanoMk 


per Ton. 


per Ton. 








d. 


£ ■. d. 


£ t. 


d. 


£ I. d. 


£ t. d. 


1 


84 


26 


n 


1 11 


2 3 


9 


2 li 


•0 3 71 


2 


85 


26 


7i 


1 11 


2 3 


9 


2 2 8 


•Oil 


3 


36 


26-5 


7} 


1 11 


2 3 


9 


2 6 5} 


1 8f 


4 


87 


27 


7i 


1 11 


2 3 


9 


2 8 31 


4 6} 


5 


88 


27-5 


7i 


1 11 


2 3 


9 


2 11 If 


7 4} 


6 


89 


28 


n 


1 11 


2 3 


9 


2 13 11^ 


10 2J 


7 


40 


285 


7i 


1 11 


2 3 


9 


2 16 9i 


13 0^ 


8 


41 


29 


71 


1 11 


2 3 


9 


2 19 7i 


15 lOJ 


9 


42 


29 


71 


1 11 


2 3 


9 


3 2 21 


18 61 


10 


43 


30 


8 


1 12 


2 4 


9 


3 5 3^ 


1 6.^ 


U 


44 


31 


8i 


1 14 


2 6 


9 


3 8 4^ 


1 1 7J 


12 


45 


32 


9 


1 16 


2 8 


9 


3 U hk 


I 2 81 


13 


46 


33 


9i 


1 18 


2 10 


9 


3 14 6| 


13 9} 


14 


47 


33 


10 


2 


2 12 


9 


3 17 11 


1 4 41 


15 


48 


85 


11 


2 4 


2 16 


9 


4 8} 


1 3 11} 


16 


49 


85 


11* 


2 6 


2 18 


9 


4 8 3i 


14 6^ 


17 


50 


35 


12 


2 8 


3 


9 


4 5 HI 


1 5 21 


18 


51 


35 


12J 


2 10 


3 2 


9 


4 8 5 


16 8 


Tablb No. 4. 


1 


34 


26 


8 


1 12 


2 4 


9 


2 11 


♦0 4 7} 


2 


35 


26 


8 


1 12 


2 4 


9 


2 2 8 


.♦0 2 1 


3 


36 


26-5 


8 


1 12 


2 4 


9 


2 6 5} 


8i 


4 


37 


27 


8 


1 12 


2 4 


9 


2 8 3f 


3 6f 


5 


38 


27-5 


8 


1 12 


2 4 


9 


2 11 If 


6 4| 


6 


39 


28 


8 


1 12 


2 4 


9 


2 13 UJ 


9 2i 


7 


40 


28-6 


8 


1 12 


2 4 


9 


2 16 9^ 


12 0^ 


8 


41 


29 


8 


1 12 


2 4 


9 


2 19 7i 


14 10^ 


9 


42 


29 


8 


1 12 


2 4 


9 


3 2 21 


17 5i 


10 


43 


30 


81 


1 13 


2 6 


9 


8 6 3i 


19 6i 


11 


4^ 


31 


8i 


1 15 


2 7 


9 


3 8 4i 


1 7i 


12 


45 


32 


n 


1 17 


2 9 


9 


3 11 5i 


1 1 8i 


13 


46 


33 


91 


1 19 


2 11 


9 


3 14 6J 


1 2 92 


14 


47 


83 


lOi 


2 10 


2 13 


9 


3 17 11 


1 3 41 


15 


48 


35 


lU 


2 5 


2 17 


9 


4 81 


1 2 111 


16 


49 


35 


iif 


2 7 


2 19 


9 


4 a 3^ 


1 3 oi 


17 


50 


35 


i^i 


2 9 


3 1 


9 


4 5 111 


1 4 21 


18 


51 


35 


121 


2 11 


3 3 


9 


4 8 5 


14 8 



Digitized by VjOOQ IC 



102 



VALUE OF ZINC-OEES. 



Calculations upon Ceudb Calamine Obb. — Contimted, 

Spcltor— £16 in Swansea, £17 in London. Weight to bo 112 lbs. per English cwt. 
Freight and Insurance, 128. 9(1. per ton. 



Tablb No. 6. 


No. 


Per- 
centage 
of Ore. 


Louhj 

Calci- 
nation. 


OoBtpor 

113 Iba. 

Engliih 

Cwt 


Total Coet 
on Board. 


TntalOort 
at Bwnniea 


Gross Value 
per Ton. 


Net Proat 
per Tun. 








d. 


£ •. ± 


£ t. 


d. 


£ I. d. 


£ >. d. 


1 


34 


26 


8i 


1 13 


2 5 


9 


2 li 


♦0 6 71 


2 


35 


26 


8i 


1 13 


2 6 


9 


2 2 8 


•0 3 1 


8 


36 


26-5 


s\ 


1 13 


2 6 


9 


2 6 5} 


♦0 31 


4 


37 


27 


8i 


1 13 


2 5 


9 


2 8 3} 


2 Of 


5 


88 


27-5 


8J 


1 13 


2 5 


9 


2 11 1} 


5 4} 


6 


39 


28 


8* 


1 13 


2 5 


9 


2 13 Hi 


8 2J 


7 


40 


285 


8i 


1 13 


2 5 


9 


2 16 9k 


11 OJ 


8 


41 


29 


8i 


1 13 


2 5 


9 


2 19 7i 


13 lOi 


9 


42 


29 


8i 


1 13 


2 5 


9 


3 2 2i 


16 5i 


10 


43 


30 


8i 


1 14 


2 6 


9 


3 5 3^ 


18 6^ 


11 


44 


31 


9 


1 16 


2 8 


9 


3 8 U 


19 7i 


12 


45 


32 


n 


1 18 


2 10 


9 


3 11 5i 


1 84 


13 


46 


33 


10 


2 


2 12 


9 


3 14 61 


119} 


14 


47 


33 


10.J 


2 2 


2 14 





3 17 n 


1 2 4i 


15 


48 


35 


114 


2 6 


2 18 


9 


4 8} 


1 1 11} 


16 


49 


35 


12 


2 8 


3 


9 


4 8 3^ 


1 2 64 


17 


50 


35 


12J 


2 10 


3 2 


9 


4 5 11:} 


1 3 2A 


18 


61 


85 


13 


2 12 


8 4 


9 


4 8 5 


13 8 










Tablb No. 6. 








1 


34 


20 


8i 


1 14 


2 6 


9 


2 li 


*0 6 7} 


2 


35 


26 


8i 


1 14 


2 6 


9 


2 2 8 


*0 4 1 


3 


8(5 


26-5 


H 


1 14 


2 6 





2 5 55 


•0 1 3J 


4 


37 


27 


H 


1 14 


2 6 


9 


2 8 3| 


16} 


6 


38 


27-5 


sh 


1 14 


2 6 


9 


2 11 If 


4 4} 


6 


39 


2S 


&i 


1 14 


2 6 


9 


2 13 Hi 


7 2i 


7 


40 


28-5 


8i 


1 14 


2 6 


9 


2 16 9J 


10 OJ 


8 


41 


29 


8i 


1 14 


2 6 


9 


2 19 7^ 


12 104 


9 


42 


29 


84 


1 14 


2 6 


9 


3 2 2i 


15 5J 


10 


43 


30 


8i 


1 15 


2 7 


9 


3 5 34 


17 64 


11 


41 


31 


91 


1 17 


2 9 


9 


3 8 4J 


18 7^ 


12 


45 


32 


9J 


1 19 


2 11 


9 


3 11 5.J 


19 hI 


13 


46 


33 


io.i 


2 10 


2 13 


9 


3 14 6f 


1 9} 


14 


47 


33 


lOf 


2 3 


2 15 


9 


3 17 H 


1 1 4i 


15 


4S 


35 


Hi 


2 7 


2 19 


9 


4 82 


1 111 


16 


49 


35 


m 


2 9 


3 1 


9 


4 3 3^ 


1 1 6.J 


17 


50 


35 


121 


2 11 


3 3 


9 


4 5 Ui 


1 2 2j 


18 


51 


85 


13i 


2 13 


3 5 


9 


4 8 6 


12 8 



Digitized by VjOOQ IC 



VALUE OF ZINC-OBBS. 



103 



Caloitlationb upon Crudb Calaminb Ori. — ConHnmed. 

Spelter— £16 in Swansea, £17 in London. Weight to be 112 Ibi. per English oirt 
Freight and Insarance, 12s. 9d. per ton. 











Tablb No. 7. 








No. 


of ^ 


Lou by 

Oalci- 


CkMtMr 


ToUlCofI 


TnUlOort 


aroMTalQa 


Vet Proflk 


Bnglkh 
Owt. 


OD Buard. 


atBwaoatM. 


par Ton. 


per Ton. 








<L 


£ >. d. 


£ t. 


d. 


£ a d. 


£ a d. 


1 


84 


26 


81 


1 15 


2 7 


9 


2 1^ 


•0 7 7} 


2 


85 


26 


81 


1 15 


2 7 


9 


2 2 8 


•0 5 1 


8 


86 


26-5 


81 


1 15 


2 7 


9 


2 5 5} 


•0 2 8} 


4 


87 


27 


81 


1 15 


2 7 


9 


2 8 8i 


6} 


6 


88 


27-5 


8J 


1 15 


2 7 


9 


2 11 1| 


8 4} 


6 


89 


28 


81 


1 15 


2 7 


9 


2 18 m 


6 2J 


7 


40 


285 


81 


1 15 


2 7 


9 


2 16 9k 


9 Oi 


8 


41 


29 


81 


1 15 


2 7 


9 


2 19 7i 


11 104 


9 


42 


29 


81 


1 15 


2 7 


9 


8 2 2i 


14 5i 


10 


43 


30 


9 


1 16 


2 8 


9 


8 5 8^ 


16 6i 


11 


44 


81 


9J 


1 18 


2 10 


9 


8 8 4^ 


17 7i 


12 


45 


82 


10 


2 


2 12 


9 


8 11 5i 


18 8i 


13 


46 


83 


lOJ 


2 2 


2 14 


9 


8 14 6} 


19 9} 


14 


47 


33 


11 


2 4 


2 16 


9 


8 17 li 


1 4i 


15 


48 


85 


12 


2 8 


8 


9 


4 8} 


19 11} 


16 


49 


85 


12i 


2 10 


8 2 


9 


4 8 8^ 


1 6i 


17 


50 


85 


18 


2 12 


3 4 


9 


4 5 Hi 


1 1 2i 


18 


51 


85 


13i 


2 14 


8 6 


9 


4 8 5 


118 


Tablb No. 8. 


1 


84 


26 


9 


1 16 


2 8 


9 


2 li 


•0 8 7} 


2 


85 


26 


9 


1 16 


2 8 


9 


2 2 8 


♦0 6 1 


8 


86 


26-5 


9 


1 16 


2 8 


9 


2 5 5} 


•0 3 3} 


4 


87 


27 


9 


1 16 


2 8 


9 


2 8 3j 


♦0 5i 


6 


88 


27-5 


9 


1 16 


2 8 


9 


2 11 1} 


2 4} 


6 


89 


28 


9 


1 16 


2 8 


9 


2 18 11^ 


5 2^ 


7 


40 


28-5 


9 


1 16 


2 8 


9 


2 16 9^ 


8 OJ 


8 


41 


29 


9 


1 16 


2 8 


9 


2 19 7^ 


10 104 


9 


42 


29 


9 


1 16 


2 8 


9 


3 2 2i 


13 5} 


10 


43 


30 


9.1 


1 17 


2 9 


9 


8 5 3i 


16 6i 


11 


44 


31 


91 


1 19 


2 11 


9 


8 8 4^ 


16 7i 


12 


45 


32 


10 i 


2 10 


2 18 


9 


3 11 5.J 


17 8i 


13 


46 


33 


101 


2 3 


2 16 


9 


8 14 61 


18 9} 


11 


47 


33 


lU 


2 5 


2 17 


9 


8 17 li 


19 4i 


15 


48 


35 


12i 


2 9 


3 1 


9 


4 8} 


18 11} 


16 


49 


35 


12i 


2 11 


3 3 


9 


4 3 3i 


19 6i 


17 


50 


35 


13i 


2 13 


3 5 


9 


4 5 lli 


1 2i 


18 


51 


35 


13^ 


2 15 i 3 7 

1 


9 


4 8 5 


10 8 



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104 



VALUE OP ZINC-OEBS. 



Calculations upok Cbudb Calamine Obx.— Continued. 

Spelter — £16 in Swanaea, £17 in London. Weight to be 112 lbs. per English cwt 
Freight and Insurance, 12s. 9d. per ton. 











Tablb No. 


9. 










Per- 


LosBby ' 
Oalci. 
nation. 

1 


Cost per 
112 Iba. 


Total Cost 


Total Ooet 


QrosB Value 


Net Profit 


No. 


centage 
of Oie. 


EnsliBh 


on Board. 


at Swansea. 
£ n. d. 


per Ton. 


per Ton. 






d. 


JE B. d. 


;e B. d. 


;e B. d. 


1 


84 


26 


9i 


1 17 


2 9 


9 


2 li 


♦0 9 71 


2 


85 


26 


9i 


1 17 


2 9 


9 


2 2 8 


♦0 7 1 


3 


36 


26-6 


H 


1 17 


2 9 


9 


2 5 5} 


*0 4 3i 


4 


37 


27 


9i 


1 17 


2 9 


9 


2 8 3f 


*0 1 5J 


6 


88 


27-6 


9i 


1 17 


2 9 


9 


2 11 If 


1 41 


6 


89 


28 


H 


1 17 


2 9 


9 


2 13 Hi 


4 2i 


7 


40 


28-5 


9i 


1 17 


2 9 


9 


2 16 9i 


7 Oi 


8 


41 


29 


H 


1 17 


2 9 


9 


2 19 7i 


9 lOi 


9 


42 


29 


H 


1 17 


2 9 


9 


3 2 2i 


12 5i 


10 


43 


30 


... 


... 


... 




... 


... 


11 


44 


31 


10 


2 


2 12 


9 


3 8 4i 


15 7i 


12 


45 


32 










... 




13 


46 


33 


11 


2 4 


2 16 


9 


3 14 61 


17 9f 


14 


47 


33 


Hi 


2 6 


2 18 


9 


3 17 H 


18 4rJ 


15 


48 


35 


12i 


2 10 


3 2 


9 


4 81 


17 11* 


16 


49 


35 


13 


2 12 


3 4 


9 


4 3 3i 


18 6i 


17 


50 


35 


13i 


2 14 


3 6 


9 


4 5 Hi 


19 2i 


18 


51 


85 


14 


2 16 


3 8 


9 


4 8 5 


19 8 



»L088. 



The meeting then adjourned. 



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TBAN8A0TI0NS. 105 



FEDERATED INSTITUTION OF MINING ENGINEERS. 



GENERAL MEETING, 

Hblb in the Booms of thb Institution of Civil Enoineebs, 25, Gbbat 

Geobgb Stbeet, Westminbtbb, June 2nd, 1898. 



Mb. GEOBGE lewis, Pbbsidbnt, in the Chaib. 



The following paper, by M. Marcel Bertrand, was read on "The 
Correlation of the Coal-fields of Northern France and Southern 
England":— 



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106 THE COBRBLATION OP THE COAL-FIELDS OF 



THE CORRELATION OF THE COAL-FIELDS OF NORTHERN 
FRANCE AND SOUTHERN ENGLAND.^ 



By MARCRL BERTRAND, Chief Enoineeb of Mines, Pbofessob of 
Geology in the Fbench School of Mines. 



I. Introductory Remarks. 

The discovery of coal at Dover, apart from its industrial importance, 
is of commanding interest from the geological point of view. It amply 
confirms the truth of the ideas to which Godwin- Austen gave expression 
in 1855, and the conclusions of many British geologists who followed in 
his footsteps. The principle from which Godwin-Austen proceeded is 
summed up in the axiom that recent folds are formed along the same lines 
as ancient folds. The correctness of this axiom once established, an 
attentive study of the surface of a given area will enable the observer to 
trace out and follow the axis of the ancient folds or convolutions, even 
when they are masked by more recent and unconformable strata. In 
particular are we thus enabled to determine along what lines we had best 
look for the continuation of known coal-basins. It may be well to add 
that the continuations of these basins will not necessarily yield coal, for 
they may be more or less extensively denuded ; but we can at any rate 
affirm that along the axis of these basins lie the most promising localities 
for the search of the mineral. 

The Somerset coal-basin is limited southward by the arch of the 
Mendips, which itself sinks eastward beneath the Jurassic rocks. These 
in turn form an arch, a gentler arch, which is prolonged still eastward 
south of London and Dover, into the Cretaceous rocks, and is, so to 
speak, emphasized by the ridge of the North Downs. Hence the 
conclusion seemed reasonable that the continuation of the Somerset coal- 
basin, if such a contmuation existed, should be found forward of that line ; 
and now the hypothesis is confirmed by the results of the Dover boring. 

Godwin-Austen had further remarked that the axis of the North 
Downs was continued on the other side of the English Channel by the 
axis of Artois, that is, by the anticlinal arch of Cretaceous rocks which 

* Translated by L. L. Beliufante, B. Sc. 



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KOBTHBRN FRANCE AND SOUTHERN ENGLAND. 107 

forms the southern limit of the Franco-Belgian coal-basin. Therefore 
it was concladed that the Somerset basin and its presumed continua- 
tions formed the direct prolongation of the Belgian coal-lBield. But the 
study of the rocks of Boulonnais has long since led French geologists to 
express doubts as to the validity of that conclusion. Coal-measures 
occur at Hardinghen and Ferques; but if these restricted outcrops be 
regarded as continuing the Pas-de-Calais basin (Lens, Auchy-au-Bois, 
Fl^hinelle), the Ime thus traced out would run far south of Dover. In 
which case the result of the Dover boring would prove that in this area 
there are at least two distinct synclinal folds, both of which, over some 
extent of their course, yield coal. 

The facts now ascertained enable us to enter more fully into the 
question than was at all possible thirty years ago. On the one hand, they 
furnish fresh arguments in favour of Godwin- Austen^s principle ; and on 
the other, they certainly tend to show that there are in all probability 
three distinct synclinal folds, along whose track coal is locally known, and 
along which one may well hope, therefore, to find the mineral again and 
again. 

These folds may be enumerated as follows : — Firstly, that of Dover 
corresponding to the Somerset basin, and perhaps also to the northern 
part of the Belgian coal-basin. Secondly, that of Hardinghen, corre- 
sponding to the northern part of the Pas-de-Galais coal-basin; and 
thirdly, a more southerly fold, corresponding to the southern part of 
the Pas-de-Galais coal-basin, and the outcrops of Auchy-au-Bois and 
FlechineUe. 

On this hypothesis the Belgian coal-basin branches out westwards 
into a series of other basins, some of which at least (Dover and Harding- 
hen) are only here and there, as it were momentarily, unproductive. 

II. Godwin-Austen's Principle— Recurrence op Folds along 

THE BAKE LiNES. 

(jodwin-Austen's principle did not fiash entirely unawares upon the 
geological mind in his 1855 paper. Murchison had already remarked 
that '' other parallel outbursts and upheavals have naturally taken place 
along the same lines . . . (those of least resistance) .... at 
subsequent epochs.''* Dana, and in his train, many geologists among 
his fellow-countrymen, generalized the idea so as to make of it the basis 
of their conceptions of American geology ; while in France, where ifelie 
de Beaumont himself had time and again appealed to the principle of 
♦ Geology of Russia, page 469. 



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108 THE CORRELATION OF THE COAL-FIELDS OF 

recurrenoes, M. Jonrdy as early as 1871, based on the same idea 
(re-christened for the nonce "law of position") the theory which he 
brought forward in opposition to the famous "pentagonal system" [sub- 
division of the earth^s surface]. Nevertheless, Godwin- Austen^s name is 
deservedly attached to the above-mentioned principle, for he was the first 
to enunciate the axiom in terms sufficiently precise to make of it an 
instrument of research. One is fain to admit, however, that his 
arguments were far from adequate for the final settlement of the question. 
They are confined to the study of the anticlinal fold which forms the 
southward limit of the coal-basins. In Prance the axis of Artois con- 
tinues the Palaeozoic axes of the Northern Ardennes, while in England 
the axis of the North Downs continues that of the Mendips : so much 
for the main idea. The original appellation has been extended to the 
various tectonic phenomena (or geological "features") noted at different 
points of that chain of axes, without sufficiently considering the evidence 
for their continuity. In fact we are here only dealing, as it were, 
with a preUminary sketch, whereas we look for a complete outline. And 
moreover the bearing of Godwin- Austen's remarks on the thickening, or, 
as the case may be, the thinning away of the Cretaceous or the Tertiary 
strata opposite the points where the coal-band becomes thicker or thinner, 
is at any rate rather questionable. When, therefore, Godwin-Austen 
concludes that between the older line of disturbance and the newer there 
is not only a general coincidence of direction, but a close resemblance 
in various geological features and structural details, his conclusion must 
be regarded as premature. The coincidence was, as Mr. Gosselet has 
recently said, amply sufficient to demonstrate the probability of the main 
hypothesis ; but it would be by no means sufficient to convert that proba- 
bility into an absolute certainty, although the case is strengthened by the 
results of the Kentish Town and Dover borings. 

III. General Concordance of the Systems of Ancient and 
Recent Polds. 

But in our day a change has come over the scene, and the merely 
probable hypothesis has been experimentally confirmed at so many points, 
that the cumulative mass of evidence may be considered as constituting 
an irrefutable proof. 

In the first place, a new argument of capital importance has been 
brought to the front, thanks to a more exhaustive study of Palaeozoic 
folds and Tertiary undulations. 

Por many a long year observers were accustomed to examine separately 



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NOBTHBBN FRANOB AND SOXTTHBRK ENGLAND. 109 

the various Palaeozoic massifs, while the possibility of correlating over 
great distances the folds which they saw in these massifs never entered 
their heads. Devonshire and Britanny, the Central Plateau of France 
and the Ardennes, the Yosges and the Harz, and the Bohemian mountains 
were looked upon as so many individual units, and the only relationship 
which it was sought to establish between them was that of the com- 
position of the different strata. Suess, the brilliant Vienna professor, 
was the first to show that these now isolated massifs are the solitary 
remnants of a single great chain which ranged right across Central and 
Western Europe till the end of the Primary epoch. It was formed, like 
the Alps of our time, by a series of minor, roughly parallel ranges ; or, in 
other words, by a series of folds whose axes followed each other at short 
intervals, keeping a parallel alignment in the fairly rectilinear portions, 
or concentric one within the other in the curvilinear portions. 

If we traced out on the map of Europe the known remaining vestiges 
of these axes we should gain a very clear idea of the general plan of the 
whole. Thus, in "Western Europe, the South of England corresponds to 
the Ardennes ; the folds of Southern Britanny and Vendfe widen out in 
the Central Plateau of France, then curve up south-eastwards so as partly 
to rejoin the Vosges and the Black Forest. True that the gaps are too 
great to permit of our following up with absolute certainty any given fold 
along the whole length of the Great Chain, but we are, at all events, in a 
position to determine the trend of an average or mean axis, which all the 
other axes doubtless follow at greater or less intervals. 

The principle thus ascertained is of enormous value, however incom- 
plete and shadowy it may appear at first sight. We may fairly say that 
it has revolutionized our methods of interpretation of the Palaeozoic 
geology of Europe. And then — a point which concerns more nearly the 
matter with which we are dealing — it allows of a generalized comparison 
with the whole system of newer folds. These may be studied at those 
very localities where the Palaeozoic folds are hidden beyond all chance of 
observation. Of course, such a study is no child's play. To begin with, 
as we all know, these folds are so slight that one would be almost entitled 
to assert that the word "fold" is improperly applied to such undulations of 
strata as those which, with few exceptions, hardly betray to the eye any 
divergence from the original horizontality. And then, from beneath the 
covering of vegetation and surface-soils, rock in place peeps out only here 
and there ; finally, the general uniformity of the Chalk, for vast thicknesses, 
and the comparative scarcity of fossils, enable one only with great difficulty 
to recognize in it and follow up any definite horizons. All these obstacles. 



Digitized by VjOOQ IC 



110 THE OORBELATION OF THB OOAT^FIBLDB OF 

however, have been overcome ; a triumph for which we have largely to 
thank that indefatigable worker, the late Prof. Hubert. Moreover, it is just 
three years since M. DoUfus, of the French Geological Survey, embracing 
the question as a whole, published for the first time in a justly celebrated 
memoir a map on the 16 miles-to-the-inch scale G oooooo) giving a general 
plan of the undulations of the Chalk in the Paris Basin.* Comparing 
this scheme of the newer undulations of the Paris Basin with that of the 
Palaeozoic folds recognized outside its borders, we at once perceive that 
the Tertiary axes follow exactly the directions along which one would be 
disposed to join up the Palaeozoic folds. Eastward, the axes sweep in 
curves which are concave towards the north, and which surround con- 
centrically the similar curve of the coal-basins. This curve in its turn 
reproduces in an attenuated form the curve of the Palaeozoic folds which 
southward surround the Central Plateau. Towards Britanny, the general 
westerly trend of the folds is not recognizable on M. Dollfus's map, 
because it has not yet been possible to trace out exactly the undulations 
in the Cretaceo- Jurassic region which borders the Western Palaeozoic 
massif. In England, however, where the undulations of the Cretaceous 
and Tertiary strata have been studied with quite as much care as in 
France, their general strike is known to be east-and-west and parallel to 
that of the ancient folds of the coast. Everywhere, then, there is close 
interdependence betwixt older and newer folds — old and new, they all 
belong to one and the same tectonic system. The recognition of this fact, 
its application not only to one fold, but to a whole series of them, vastly 
increases the balance of probabilities in favour of Godwin-Austen's law. 

If we wished to go farther, we should need to do in the case of each 
fold what Godwin- Austen was enabled to accomplish in the case of the 
North Downs, namely, follow it up to the Palaeozoic boundary and prove 
that it is there in contact with and joins on to a fold of the older strata 
running in the same direction. Unfortunately, the demonstration is in 
most cases a matter of great difSculty. The Jurassic rocks which crop 
out at the junction with the Palaeozoic swerve sharply westward, and 
thereby mask, as a rule, the effects of the folding. One exception, 
however, may be noted : the Merlerault Tertiary axis, one of the most 
considerable folds in the north of the D^partement de la Sarthe, has been 
recently shown by M. Lecornu to be an unmistakable prolongation of a 
Palaeozoic axis.t 

If we sum up what precedes, limiting ourselves to such points as are 

♦ Bull des 8erv, de la Carte GSol. de France, July, 1890, No. 14, vol. ii. 
t Bull. Sue. Linn, de Norm.y 1889, series 4, vol. ii. 



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KOBTHBEN FRANCE AND SOUTHERN ENGLAND. Ill 

beyond dispute, we find that (1) the Bystem of Tertiaiy folds is arranged 
parallel to the main strike-lines {lignea directrices) of the older folds, 
following all their inflections ; (2) in the case of the only two anticlinal 
folds which have as yet been traced up to the Palaeozoic boundary, there 
is at the junction absolute coincidence, in position and in direction, 
with an anticlinal fold of the Primary rocks. 

IV. The Bearing of Marine denudation on the Question 
OF THE Folds. 

Yet another series of arguments may be drawn from the study of 
ancient surfaces of marine denudation produced by the successive returns 
of the sea in Cretaceous and Tertiary times. This study in fact shows 
that there have been considerable movements, both in the comparatively 
short interval of time which separates the latest Jurassic deposits from 
the earliest Cretaceous, and in that which separates the latest Cretaceous 
from the earliest Tertiary. In some areas, at any rate, the movements 
produced in those intervals may be isolated from all others and studied 
quite independently : thus we find that though slight, the movements 
under consideration have given rise to true folds, and the axes thus formed 
coincide absolutely either with those of more recent folds, or with the axes 
which result from the superposition of all these movements. 

The possibility of such a study is based on the fact that the sea in its 
gradual advance eats away the shore-Une and planes down the old surface 
of the land, substituting, for the hills and valleys formed by older move- 
ments or carved out by atmospheric erosion, the practically horizontal 
surface of a plain of marine denudation. The new sea-bottom, if it could 
then be examined, would show almost a horizontal section of the older 
deposits ; and a geological map of this sea-bottom would enable us to 
form a fair idea of the main features of the strata of which it is made up. 
The anticlinal folds would be marked by bands of outcrop of the more 
ancient rocks, or by noticeable indentations of their contours ; conversely, 
the synclinal folds would be marked by bands of newer rocks ; and lastly, 
supposing that the beds were not folded previous to marine denudation, 
but simply bent up in one mass towards some prominent massif corre- 
sponding to the ancient shore-line, the outcrops would occur in parallel 
bands whose contours would follow that shore-line in parallel order. If 
we wished to retrace such geological maps of the ancient sea-bed, it would 
evidently suffice to distinguish and to limit each of the surfaces along 
which the overlapping strata rest upon the various older rocks.* 

* " Continuity du Ph^nom^ne de Plissement dans le Bassin de Paris," Bull, 
Soe. QSol. France^ 1892, vol. xx., page 118. 



Digitized by VjOOQ IC 



112 THE CORRELATION OV THE COAL-FIELDS OF 

V. The Folds in Boulonnais. 

To take the district of Boulonnais as an instance, if we glance at the 
present geological map, we notice at once that the Lower Cretaceous (Weal- 
den) rests indifferently upon all the Jurassic horizons, and that the Upper 
Portlandian is its immediately succeeding substratum in two small areas 
only, north and south of Boulogne respectively. The very insignificance 
of these areas proves how restricted was the outcrop of the Upper Port- 
landian on the Cretaceous sea-bed. 

So too, in ascertaining the localities where the Cretaceous rests upon 
the Lower Portlandian, we see that the contour of the newer series 
enveloped that of the preceding series, repeating analogous sinuosities. 
Going thus backwards by successive series we find ourselves in. a position 
to trace out the geological map of the bed of the ancient Cretaceous sea 
(Fig. 1, Plate IV.). The very form of the contours shows that their 
irregularities could not possibly correspond with old valley-bottoms; 
they point, therefore, to undulations of the sea-bed already existing 
when the sea returned, and thus afford evidence of pre-Cretaceous folding 
of the rocks. 

If we are desirous of comparing these movements with those which 
the same surface has undergone since that epoch, we need only plot out 
(Fig. 2, Plate IV.) the contour-lines (courbes ds niveau) of the base of 
the Cretaceous, as it now is. These contour-lines demonstrate, firstly, 
the existence of two median protuberances, one of which corresponds to 
the Palaeozoic massif of Ferques, and the other to the site of the ancient 
Forest of Boulogne; but apart from this simultaneous movement (of 
which there was no sign before Cretaceous times), we notice that the 
contour-lines describe around the central dome a series of indentations 
and prominences which indicate that a set of parallel undulations ranged 
across the whole area. The axes of these post-Cretaceous undulations 
coincide with those previously observed in the case of the pre-Cretaceous 
undulations, and we therefore conclude that it is precisely on the site of 
the last-named that the later folds have been formed. 

The verification of these facts in Boulonnais is especially important 
from the point of view of those who search for the continuation of the 
Coal-measure synclinals, for it is precisely around that area that we 
should look for these synclinals to be continued. 

As to the foldings included between the Cretaceous and the Tertiary, 
the work of M. Cayeux has enabled the writer to complete an analogous 
verification in the P^ronne-St. Quentin area, to the south of Arras 
(Fig. 8, Plate IV.). 



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NOBTHBRN PRANCE AND SOUTHERN ENGLAND. 113 

The same method is applicable in the south and west of the Paris 
Basin, and in the west of the London Basin ; and it leads to the same 
resalts. Armed thus with so many examples which confinn one another, 
we cannot possibly be taxed with reliance on mere fortuitous coincidences. 
During the whole duration of Secondary and Tertiary time, the crumplings 
of the surface in our part of the world have recurred again and again 
along the same lines. 

VI. — The Folds in the Nord Coal-basin (Plate V.). 

The interest of the subject gains by extending a similar method of 
study to an area where Cretaceous overlie Palfeozoic strata. The coal- 
basins of the North of France offer peculiar advantages in this respect, 
for there the underground workings necessarily connecttMi with mining, 
make known to us both the appearance of the older rocks and that of the 
surface upon which rests the Cretaceous Series. 

One might, however, question the applicability to the present case of 
the idea of a plain of marine denudation; and, indeed, the deposits 
which overlie the Palaeozoic in this urea are not everywhere exactly 
contemporaneous. Moreover, if we remembered that these strata are 
generally tough and long-resisting, we might expect that the ocean waves 
would hardly have succeeded in all places in breaking down the 
irregularities of the ancient land-surface, we might expect that some 
protuberant island-like masses would have withstood their efPorts, and 
that some traces of old valleys would have been preserved. But, as a 
matter of fact, the contour-lines which have been recorded, betray no 
irregularities such as would remind us of the topographical relief due to 
the carving-tools of subaerial denudation, and such as we should expect if 
marine denudation had been hindered in its differently destructive work. 
Then, too, in the case of old valleys, we ought to find fluviatile deposits 
at the base of the Cretaceous, or at least, we ought to find an increased 
thickness of basement-beds at these points. Such is the case in the Anzin 
"wash-out" (torrmt (T Anzin), but that is, so far as known, an unique 
occurrence in this area. 

As to the difference of age or non-contemporaneity of the basement- 
beds, the sole error thereby made possible is due to the movements which 
may have taken place between the various phases of denudation. If these 
were folding movements, then it matters little ; for, as we have seen 
above, we have merely to deal with a superposition of movements along 
the same lines. If they were movements of a different nature, the part 
which they played can be determined just Jis easily if they preceded as if 

VOI« V.-181«.M. 8 



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114 THE CORRELATION OF THE COAL-FIELDS OF 

they succeeded the process of marine denudation. The real problem 
that has to be solved is — the recognition, amid the inequalities of the 
contour-lines, of those which are due to folding. It is often difficult, 
sometimes impossible, to arrive at a perfectly certain solution ; but the 
same difficulties await us in connexion with the topographic surface of 
any stratum whatsoever as with that of the Primary land. The important 
point, in both cases, is to have contour-lines which are exact, and fairly 
close to one another. 

We are then justified in holding that the interpretation of the contour- 
lines of the surface of Primary rocks is likely to emphasize the existence 
of crumpling phenomena, and will allow of our comparing these more 
recent "puckcrings" with the folds of the Coal-measures. 

The contour-lines of the Primary land-surface were plotted out by M. 
Potier on the geological ^77^757^ or 1 J inch map, at equal distances of 50 
metres (164 feet). A glance at these contour-lines reveals at the two 
extremities of the French northern coal-field the exact coincidence of 
the younger depressions with the Coal-measure basin. North-east of 
Valenciennes, the crowding up together of the contour-lines points to a 
very deeply-hollowed basin, to which M. Olry gives the name of "Valley 
of Vicq ;" the difference of level between the rim of that basin and the 
central hollow exceeds 500 feet. It can be followed in an easterly 
direction to beyond Mons, and coincides along its whole course with the 
Coal-measure basin. Moreover, south of this basin, another inflection of 
the contour-lines is noticeable around Quarouble: here the secondary 
basin is superposed on the small Coal-measure basin of Dour. 

Westward, a very strongly-marked inflection of the contour-line ( — 50 
metres, that is, — 164 feet,) (Plate VI.) points to a similar synclinal 
undulation of the surface, situated exactly over the spot where the Coal- 
measure band thins away, between Bruay and Fl^hinelle. But between 
these extreme points, the contour-lines, which are 164 feet apart, fail to 
demonstrate the existence of a series of parallel undulations : the Primary 
land-surface thus apixjars to be an irregular, hummocky, but not a 
folded area. \VTience we can only conclude that the undulations, if 
they do exist, are too slight to be noticed in plotting-out contour-lines 
which are so far apart as 164 feet. The facts at our command are 
now sufficient to allow of drawing contour-luies only 82J feet apart; 
a glance at the map thus obtained then shows at onct; that the 
surface is folded. We notice first, in the central portion, a great line 
of depression (the Vicoigne fold) which is everywhere below the 262 
feet level : it starts from the deep basin of Vicq, and runs south of the 



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NOETHBBN FBINCB AND SOUTHEBN BNGLAND. 116 

Vicoigne mining property. In the Anzin mining property, relative 
depressionfl rarely exceed 65 feet, but three are arranged in a remarkable 
way parallel to the rim of the basin (Aniche fold, Denain fold, and 
Azincoart fold). The rim corresponds to a sort of "swelling" or 
bulging out, which follows it right along from the Belgian frontier 
to Douai. Lastly, farther south, though the available data are less 
numerous, we believe that another synclinal fold may be traced almost 
continuously : its presence was betrayed near Dour, as already observed, 
thanks to the contour-lines drawn by M. Potier. We have here, then, with- 
out taking into account the mining areas of Fresnes and Bruille, no less than 
five distinct synclinal folds which may be followed right across the map. 

It now remains to be seen what is the relation between the position of 
these folds and the position of the folds of the older rocks. To begin 
with, the general trend is much the same as that of the Coal-measure 
basin, but the conformity goes deeper yet, and, deep as it goes, will still 
be found remarkably close. 

Begiiming with the north, the synclinal fold of Vicoigne occurs only 
in that mining property above the underground workings ; and there a 
triplicate synclinal fold has been observed, the southern flanks of which 
are pushed abruptly upwards and even slightly turned over (Fig. 4, 
Plate IV.). The recent fold coincides in jx)sition and strike with the 
southernmost of these folds ; above the two others is an area where it has 
hitherto been impossible to determine the contour-lines with suflScient 
precision to ensure trustworthy data. 

The next fold, that of Aniche, occurs westward near Aniche, and east- 
ward near Anzin, north of the Cran de Retour ("doubling-baok") fault ; 
somewhere between those two localities it runs south of that fault. If we 
consult the map of the different zones of the coal-field, published by M. 
Zeiller,* we notice that that contour follows almost exactly the boun- 
dary of zones B* and B* (lower and middle regions of the middle zone), 
restoring that part of the zone which is cut off by the Cran de Retour. 

Now, in the Palaeozoic rocks, there are signs of a synclinal fold 
corresponding to the north of the Cran . de Retour. These may be 
observed in the workings of the Thiers pit and the St. Louis pit (mim'ng 
property of Raismes). Farther westward, the fold, if it be continued, is 
thrown deeper by the Cran de Retour, but reappears, well-marked and 
easily recognizable, in the workings of the Douai and Escai'pelle area. 
Besides affecting the same group of beds as elsewhere, it coincides in that 

* Bassin houiller de Valenciennes. Description de la Flore Fossile^ p&ge 692, 
Fig. 46. 



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116 THE CORRELATION OF THE COAL-FIELDS OF 

area with the Tertiary fold. It is feir, then, to say that the coincidence 
is interrupted by the fealt only, that fault not having moved or worked 
back at the same time as the folds. 

The next two folds, that of Deuain and that of Azincourt, correspond 
to the southern part of the basin. It would be useless to attempt to seek 
a precise coincidence with one or other of the numerous folds of this 
portion of the coal-basin, the more so that the Azincourt fold can only 
be traced with certainty in the mining: property of that name, where 
it remains outside the limits of the basin. The last mentioned circum- 
stance is perhaps explicable if we consider that the older fold is there 
turned over (coucM), and Devonian and Carboniferous strata overlie 
the centre of the coal-basin. All we can look for is a general coinci- 
dence, and so much is an undeniable fact. The Denain and Azincourt 
folds correspond in strike with the zone B' of M. Zeiller (upper division 
of the middle zone). 

It is noticeable that the Aniche and Denain folds cross, and follow the 
middle portion of, the wash-out (torrent) of Anzin. The sands to which 
this name has been given date, as we know, from the Lower Cretaceous; 
they are probably fluviatile, and are in any case anterior to the period of 
the final return of the Cretaceous sea to that region. That these sands 
were more likely laid down, and more easily preserved, in a synclinal 
depression seems sufficiently obvious. 

Lastly, as to the fifth fold, that of Dour, its coincidence on the west 
side with the little Secondary basin of the same name has already been 
noted in these pages. Towards Douai it unites, outside the limits of the 
coal-basin, with the western branch of the deep depression of Douai. 

The result of the foregoing considerations tends then to show that 
there is a coincidence between ancient folds and recent folds ; that this 
coincidence appears to extend to minute details, and to exceed in pre- 
cision all that one might have expected from phenomena, which, owing to 
the complex nature of the resistances that come into play at every point, 
can hardly be adjusted to geometrical laws. The confirmation of our 
principle is so convincing as to admit of no doubt. 

The accompanying section (Fig. 4, Plate IV.) enables us to compare the 
features of the strata which are now being worked for coal, with those of the 
land-surface of Primary rocks (tlie heights of which are exaggerated thirty 
times). The section shows that repetition of folds along the same lines 
does not result in the formation of similar surface-reliefs, where the newer 
system of folds reproduces on a smaller scale the older one. One reason 
is that there is no projwrtionality in the relative accentuation of the 



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NORTHEBK FRANCE AND BOUTHEBN ENGLAND. 117 

various folds which are superposed one upon the other. Moreover, the 
Yicoigne depression has all the look of belonging to another order of 
phenomena ; it is in fact the rim of the Yicq depression, where a local 
subsidence is superposed on folding, and where four out of our IGive folds 
unite and mei^ into one- another. We conclude then, that, over a con- 
siderable area, the general inclination of the more recent strata is the 
reverse of the inclination of the older beds, wherefore there is absolute 
divergence between the two profiles. The influence of the folding action 
is none the less marked in the general trend of the contour-lines, and this 
is chiefly owing to the parallelism of the undulations. 

VII. The Folds in the Pas-de-Calais Coal-basin. (Plate VL). 

It would be interesting to studj from a similar standpoint the Pas-de- 
Galais area. Meanwhile, by the mere inspection of the curves plotted out 
by M. Potior, some not unimportant conclusions as to the geology of the 
coal-field may be arrived at. Even on small-scale maps (of France, say, 
^ ^^ icooooo > 9^ ^^ miles to the inch) it will be seen that the northern 
rim of the coal-basin shows numerous sinuosities, as for example near St. 
Anumd, Annoeulin, and B^thune. The localities where the Carboniferous 
Limestone thus protrudes intx) the coal-field evidently denote remnants of 
anticlinal folds of the older strata — at least, such is the case if we admit 
that the Primary land surface (or surface of erosion) was formerly 
horizontal ; conversely, the areas where the Coal-measures form promon- 
tories projecting into a mass of older strata, correspond to synclinal 
folds. Now, in the D6partement du Nord, as will be seen by the map 
(Plate v.), the synclinal fold which occurs north of Vicoigne, in other 
words, the fold of Vieux Cond6 (to which the writer has not hitherto 
referred) terminates near St. Amand, issuing from the coal-basin precisely 
on the site of one of these synclinals. Similarly, the northernmost of the 
two folds which was mentioned as corresponding to the Vicoigne fold, 
issues from the coal-basin near Marchiennes, in the second of these 
synclinal creeks. The track (so far as yet known) of the southernmost 
of these two folds, if continued into the Pas-de-Calais, leads one to infer 
that after passing by Ostricourt it issues from the basin at Annoeulin, 
while the Aniche fold issues therefrom south of B^thnne. 

Here, again, then, we have a series of coincidences, the importance of 
which can hardly be overlooked. And from the point of view of the 
tectonic structure of the coal-basin an instructive conclusion may be 
drawn, viz., that this basin does not correspond to a single fold, but 
to a set of folds, slightly oblique to the mean strike of the coal-bearing 



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118 THE CORBEIxA^TIOK OF THE COAL-FIELDS OF 

band, a conclusion which throws a new light on the overlap of the coal- 
bearing strata, and to which M. Potier long ago drew attention.* 

In fact, if we combine the foregoing data with the results attained 
by M. Zeiller's map, we shall see that the Vieux-Cond6 fold, or rather the 
anticlinal fold which limits it to the south, practically corresponds with 
the boundary of the anthracitic group (A^ of Zeiller) ; the Vicoigne fold 
with that of the Nord close-burning coal group (A*); while the Aniche 
fold, which may be regarded also as that of B^thune, corresponds (as 
already remarked), with the boundary of the zones B* and B*. In 
other words, the very folds with which we have been previously dealing, 
foreshadowed or dimly outlined before the Coal-measure upheaval, have 
successively checked the progressive southward advance of the Coal- 
measure lagoons. Wherefore, if at a given locality we know by fossil 
evidence the age of the Coal-measure horizon which rests upon the Car- 
boniferous Limestone, or at any rate upon the latest unquestionably marine 
strata, we may, to some extent and with some chance of probability, con- 
clude which is the fold uix)n whose prolongation that locality is situated. 

The information would be valuable, for instance, in the case of the 
district of Boulonnais, but unfortunately no precise data have as yet been 
obtained from the coal-flora of that area. It may be as well to add, 
however, that in no case could such a conclusion be accepted unreservedly, 
because a fold which constitutes a shore-line along part of its course does 
not necessarily continue so along its whole course. But one conclusion we 
may at all events bear in mind, and that is, that over the North of France 
coal-field, the recent folds are, as it were, moulded upon the older folds. 

VHI. Summary of conclusions drawn from the evidence in 
THE North of France. 

To sum up, the arguments which may be invoked in favour of 
Godwin- Austen's princii)le are the following : — General concordance in 
the " scheme " of the Palaeozoic folds and that of the recent folds. Exact 
superposition in the various phases of the later folding. Unbroken 
junction at their common extremities of several folds belonging to both 
series {eu/,^ Meiidip Hills and Merlerault). Complete and continuous 
coincidence of both scries above the coal-basin of the Departement du 
Nord. 

One may be inclined to generalize from these results, or the reverse ; 
one may seek to reserve the possibility, at any rate, of important exceptions 
to the rule; but there is now no doubt that, so far as the North of France 
and the South of England are concerned, the observer may be guided by 

• Asmw, Frang.p. VAv. den Scienceii, 3"™* session, Lille, 1884. 



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NORTHERN FRANCE AND SOUTHERN ENGLAND. 119 

the nndnlations of mor^ reoent strata in looking for the axes of the 
Palaeozoic folds. It is no less certain that in a search of that kind the 
observer may take as a basis the contour-lines of the surface of any 
particular bed in the series or of any surface whatsoever of ancient 
marine denudation. It should be borne in mind, however, that the rule 
necessarily loses much of its precision in those cases where the ancient 
folds are " dissymetric " or overfolded, because a single line drawn along 
the surface is hardly suflScient to define the site of an *' overf old " {pU 
coucM), 

IX. Application op the principle to the Coal-basins of the 
Pas-db-Oalais, the Boulonnais, and Dover. 

The first problem which demands solution is to join up the known 
folds (near the extremity of the Pas-de-Calais coal-basin) and those which 
have been already determined for Boulonnais. The data available in 
the intervening area unfortunately are so far inadequate. We can only 
make use (Plate VI.) of the contour-lines of the surface of Primary 
rocks, plotted out by M. Potier in his detailed geographical map, and 
farther westward the contour-lines of the base of the Chalk- with-ifwras/^- 
brevijmrus^ obtained from a recent work by M. Parent.* 

In examining the surface of the ancient rocks one is struck by the 
island-like protuberances which run higher than the 164 feet contour. 
Southward runs the long saddle [ridge] of Fauquembergue and Vimy, 
with the subsidiary promontory which juts out westward of Fruges towards 
Hucqueliers ; farther north lies the little prominence of R^bergues (where 
the Devonian crops out), and lastly, the massif of Ferques, north of 
Boulonnais. Putting aside for a moment the protuberance of Hucqueliers, 
it seems natural to assume that the line of Ferques-R^bergues-Fauquem- 
bergue represents, despite some depressions along its course, an anticlinal 
axis, northward of which the continuation of the Coal-measure" synclinal 
should be sought. Such was thfe solution favoured by Godwin-Austen and 
recently maintained by Dollfus.f But the writer firmly believes that an 
attentive study of the contour-lines will entail its immediate rejection. 
To begin with, this line does not present everywhere the same character- 
istics. True, that from Ferques to Rebergues, the Primary land-surface 
sinks on either side of the line ; and the same statement holds good east 
of Fauquembergue, but in the intervening space the conditions are 
different. The base of the Cretaceous, which, from Flanders onwards, 
rises continuously towards that line, continues to rise on the other side 

♦ Annates Soc. OSol. Nord, vol. xx., page 304. 

t Bull- des Serv, Carte Oeoh France, vol. ii., No. 14. page 49. 



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120 THE COEBBLATION OF THE COAL-FIELDS OP 

of it towards the centre of Boulonnais. The line, for a distance of 12 
miles, ceases to mark the separation between two declivities — it loses the 
character of an anticlinal axis. On the other hand, there is a well- 
marked anticlinal axis south of St. Omer, which runs thence a little above 
Lumbres. Lower down a parallel synclinal fold is equally well-marked 
between Aire and Eemilly. These two folds are oblique to the R^bergues- 
Fauquembergue line, and denote the true direction of the whole system. 
We may add, as was long ago observed by M. Gosselet, that the Artois 
axis (or axis of Condros) has everywhere to the east formed the northern 
shore-line of the Lower Devonian sea. The absence at Ferques of rocks 
of that age being amply proved, the inference is obvious that this locality 
lies north of the prolongation of the fold. And thus we are supplied with 
yet another argument for concluding that the Artois axis does not run up 
to the north of Boulonnais 

Another solution which appears to offer itself quite naturally is the 
joining up of the Pas-de-Calais coal-basin (Auchy-au-Boisand Flechinelle) 
with that of Boulonnais. As a help to this solution we may recall the 
existence of a great overturned fold south of both coal-basins. M. Breton* 
objects, on the score of the difference of composition of the Coal-measures 
in the Pas-de-Calais and Boulonnais respectively. The contour-lines 
offer no obstacle to the solution, but they indicate os more probable the 
correspondence of the Hardinghen " system " with the Secondary synclinal 
of Bethune. 

Lastly, M. Parent has shown that the depression which limits 
Boulonnais southwai^d, between Neufchatel and Ergny, was prolonged 
north-eastward towards Delette by a less strongly-marked depression, and 
appeared thus to join up with the Flechinelle synclinal. But an attentive 
study of the contour-lines shows that in reality the depression bifiircates, 
and the branch which runs down towards Frages alone corresponds to the 
general scheme of the system of folds. Perhaps the diverging ramification 
of Delette is neither more nor less than the tag (amorce) of a circum- 
ferential depression around the central dome of the Forest of Boulogne. 
Neither, therefore, does the Artois axis run south of Boulonnais. 

Its continuation should at aU events be looked for within Boulon- 
nais itself, but the insufficiency of the data at present available only 
enables us to infer its termination north or south of Wimille. The 
Flechinelle synclinal axis would then on one hypothesis debouch at Cape 
Oris Nez, on the other near Wimille. The vmter may add that, indepen- 
dently, five anticlinal and synclinal folds have been determined near 
Bethune, and five similar folds in Boulonnais ; further, that the junction of 
* J nn. iSoc. Giol du Xord, vol. xix., page 24. 



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NORTHERN FRANCE AND SOUTHERN ENGLAND. 121 

the extreme folds of the double series has been ascertained, and that conse- 
quently there is a great balance of probability in favour of the junction 
pair by pair of the intermediate folds. Thus the axis of Artois is 
correlated with the fold of La Cr6che, so well marked in the Jurassic 
diffs north of Boulogne.* 

X. The Evidence from Borings. 

Comparatively few borings have been made in central and southern 
Boulonnais. M. Rigaux, in his very complete memoir on that districtt 
says, with due reservation, that old borings are supposed to have struck 
the Silurian rocks at Mont des Boucards and Le Wast. MM. du Souich 
and Delanoue refer to the Silurian shales which have been met with in 
a boring at Lottinghen. These somewhat doubtful results would, if 
confirmed, indicate the existence of an old anticlinal below the recent 
anticlinal of the upper valley of the Liane. 

Borings between R^bergues aud EscoeuiUes have struck the*Carboni- 
ferous Limestone, limited north and south by the Devonian ; therefore, the 
old synclinal of Hardinghen passes just at the spot whither we have traced 
the newer synclinal. Two borings, at Moulin-des-Moines and Basse 
Falaise, south of Hardinghen, have struck, one the Carboniferous Lime- 
stone below 790 feet of Devonian slates, the other Coal-measure shales (82 
feet only) below 633 feet of Carboniferous Limestone and 265 feet of 
Devonian slates. The prolongation southward of the overturned fold 
serves to explain why the recent synclinal is there carried some distance 
south of the outcrop of the older synclinal. 

Unfortunately, however, farther south, just where information would 
be most interesting, very few borings have been made. That of Desvres, 
at 768 feet, struck clay-slates, on the age of which M. Rigaux offers no 
opinion, while M. Gosselet is tempted to refer them to the Lower Coal- 
measures. A more recent boring, the exact results of which are unknown 
to the writer, seems to have confirmed that supposition, and it would in 
fact agree with the known existence of a recent synclinal at Desvres. 

Lastly, a boring has been carried on at Boulogne itself at the factory 
of Montataire. The boring was at first stopped at 777 feet in a very tough 
Oolitic limestone, regarded as Carboniferous Limestone. Thereafter the 
boring was deepened by 197 feet, the whole thickness of which cousisted 

* Since the paper was written M. Parent has sent the writer some new observa- 
tions which modify the geological information and maps upon which this conclnsion 
was based. The writer is now induced to admit that the Artois axis passes to the 
sonth of Boulonnais. Practically, however, this does not affect the other conclusions 
of this paper. 

t Notice OSol, tur le Beu Boulomutu^ Mew. Soc, de Bovlogne^ 1892. 



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122 THE COBRBLATION OF THE COAL-FIELDS OF 

of white sands and lignite-bearing clays ; these represent, beyond any 
possibility of doubt, the base of the Jurassics of that district. So that the 
Oolitic limestone, erroneously attributed to the Carboniferous, is really 
Bathonian [Great Oolite]. The boring was not continued beyond 981 
feet, and though at that depth it had not yet struck the PaldBOzoic rocks, 
it must have been close upon them. 

XI. Application of the Preceding Considerations to the 
Dover Basin. 

Prom the foregoing considerations we are enabled to conclude that the 
Pas-de-Calais coal-basin, whether or not ramifying into two distinct 
branches in Boulonnais, does not debouch on the coast anywhere north of 
Cape Oris Nez. The anticlinal fold which forms the northern boundary 
of Boulonnais corresponds to that which, near Folkestone, forms the 
northern boundary of the Weald. We are therefore led to the further 
conclusioh that the newly-discovered coal-basin of Dover is distinct from 
the Pas-de-Calais coal-basin. 

In looking for the prolongation of the Dover coal-basin we notice that 
the contour-lines of the base of the Glauconitic Chalk [Chloritic Marl] 
Indicate near the coast the existence of a series of undulations sensibly 
parallel to the shore-line. These undulations are moreover parallel to 
those which furrow the neighbouring sea-bed of the North Sea and the 
Straits of Dover. Clearly, they make up a system which is transverse 
and practically perpendicular to the system of principal folds which run 
across the Straits, and therefore they provide us only with indirect 
guidance as to the axes that we ought to follow up. 

But this does not hold good of the contour-lines carried along beneath 
the Straits by MM. Potier and de Lapparent. These give evidence of a 
sudden drop of the strata northwards, which is sufficient to mark, if not 
the exact position, at all events the average direction, of the fold which 
starts at Folkestcme. Bearing in mind that this sudden drop of the 
strata is paralleled by the raj)id downward plunge of the Aptian Beds 
[Lower Greensaiid, and Atherfield Clay-beds], observed on the French coast 
near Wissant, we are enabled to plot out approximately the actual axis 
of the fold, whereby we gain the conviction that it ultimately joins up 
with the saddle of Ferques. And the line thus traced is found to be very 
nearly perpendicular to the great furrows of the sea-bed. 

We are acquainted, moreover, with a small Secondary saddle on the 
Kentish coast between the Folkestone fold and the Dover coal-basin. 
The submarine outcrops here also enable us to follow for several miles the 



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NORTHERN FRANCE AND SOUTHERN ENGLAND. 123 

axis of this Secondary fold which bends rapidly eastward and even north- 
eastward. So we have one more valuable junction-tag. 

If we wish to follow still farther these tags or remnants, our one 
remaining resource is to study the contour-lines of the present sea-bed. 
This bed, like that of the ancient seas, is a surface of marine denudation, 
and the same conclusions are here applicable as there. True, that in the 
case of our recent seas the objections urged in another portion of this 
paper seem to acquire additional strength. In the North Sea the aocum- ♦ 
ulation of glacial detritus, and in the Straits of Dover the part played 
by the sea-currents appear amply sufficient to vitiate our conclusions; 
and yet, despite the intervention of causes of error so undeniable, the 
general scheme of the folds has not been obliterated. The contour-lines, 
both in the North Sea and the English Channel,* make strikingly 
manifest a double system of rectangular furrows, which join up with the 
folds already known on either shore. We make, therefore, no very rash 
assumption if we presume that the study of these contour-hnes will in this 
particular case provide us with some useful data. No doubt the indications 
thus obtained will be merely approximate ; because, for one thing, the 
transverse furrows alone are well marked in the Straits, and for another, 
the sinuosities of the contour-lines around these furrows are both too 
minute and too numerous to allow of our plotting-out the second system 
with anything like precision. In point of fact, for the purposes of that 
scheme, we are led to rely on the condition of perpendicularity (of one 
system to the other), and this is, and can only be, a matter of approxima- 
tion. The only well-known fold on the English coast, besides those 
mentioned above, is the Thanet axis,t of which one might, perhaps, 
place the termination at Ostend (where boring has proved the Silurians 
at 984 feet) ; the Hougham Fold, starting immediately south of Dover, 
terminates near Calais (Fig. 5, Plate IV.). 

It is therefore between those two points that we ought to look for the 
continuation of the Dover coal-basin. Whether intermediate undulations 
occur between the Isle of Thanet and Dover is unknow^n ; nor do we know 
whether Dover is near to or far from the axis of the Coal -measure synclinal. 
All that we can say, as the result of the application of our method, is that 
the homologous point of Dover would in France lie a little east of Calais. 
If the Dover coal-basin does reach into France, its continuation must 
therefore be sought east of Calais, between that town and Dunkirk. 

* Bv-U, 8oc, OSol. France, vol. xx., page 156. 

t M. BaiTois considers that the Thanet axis is a tran verse fold; but I am 
unable to agree with him herein, for it appears to me that the Thanet axis is 
evidently continued by the outcrops of Chalk mapped along the Thames. 



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124 THE COEBBLATION OP THE COAL-FIELDS OP 

The writer would add one remark which seems to him important from 
the theoretical point of view : if the folds of the Nord, as he has said, 
ran slightly oblique to the Coal-measure band and debouch in the 
successive creeks of the rim of the coal-basin, it becomes highly probable 
that it is the Vicoigne fold that has been met with at Dover. Whence 
we would infer that the coal-basin of the Nord branches out westward 
into a series of ramifications, some of which, at all events, only inter- 
mittently cease from being productive. 

It is known that a boring was formerly undertaken at Calais, but 
unfortunately the results are doubtful and much disputed. The boring 
was stopped at a depth of about 1,150 feet, after having below the 
Greensands passed through about 35 feet of a foetid, sub-Oolitic limestone, 
regarded by some as PalsBOZoic. M. Laurent, who directed the boring 
operations, hints at Coal-measures, an assertion which seems hardly 
tenable, ^lie de Beaumont, who saw the specimens brought from the 
bottom, assigned them to the Carboniferous Limestone, and that appears 
the most likely view. On the other hand, the oolitic character of the 
rock has led observers to suppose that here, as at the Montataire factory, 
Jurassic limestone had possibly been confounded with Carboniferous. 
The specimeiTs which passed through the hands of ^ie de Beaumont have 
not been traced, in spite of the search made by M. Potier, and there is 
reason to fear that this doubtful point will never be settled, unless a new 
boring be made.* 

The \iTiter has already mentioned the Ostend boring, which proved at 
984 feet the Silurians immediately below Tertiary strata. Three other 
borings (near Guines and St. Omer) have also proved very ancient rocks, 
probably Devonian and Silurian. None of these data, however, help to 
solve the problem, 

XII,— General Conclusions. 
The object of this memoir, a purely geological piece of work, is not 
and could not be, the prediction of the occurrence of Coal-measures at 
such and such a spot. The method we have adopted simply enables us to 
follow at the surface the axes of known coal-basins. But we should also 
require to know whether Coal-measures, in the area we have studied, 
were laid down along the whole extent of these basins. The westward 
overlap of the different divisions of the Coal-measure series shows that the 
shore-line of the Coal-measure lagoons lay to the west, and the occurrence 
of coal at Hardinghen leads us to infer that this shore-line was situated 

* The CalaiB boring If. tuljed, and may be deepened at any time. 



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S ^irSouJthmi En ghmdi 



Vol. Y. Flats V, 




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raiice Jl S outhern England/ 



Vol. V Plate W, 



FiG.7. 
Map of the Cbbtacbous and Tertiary Uxdui.ations 



Pas-de-Calais. 



REFERENCES. 



OONTOUR LINES OF THE SURFACE OF 
PRIMARY ROCKS. INTERVALS OF 
164 FEET. 
ANCIENT ROCKS ABOVE 164 FIET. 
„^^ CONTOUR LINES OF THE BASE OF THE 

CHALK WITH Micraster breviporua. 



..CONTOUR LINES OF THE BASE OF 

THE CRETACEOUS (wEALDEN 
INTERVALS OF SS FEET. 

.._._ SYNCLINAL AXIS. 

,^^^ ANTICLINAL AXIS. 

COAL BASIN (tOURTIA OUTCROp). 



•.aaimiil] « 



Scale -5^oVo5 




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NORTHERN FRANCE AND SOUTHERN ENGLAND. 125 

beyond the area of Boulonnais. So much is very probable. But the 
mere occurrence of Ooal-meaBures, granted that it be proved, does not 
necessarily imply the occurrence of coal. 

We should further require to know at what points of the basin 
Goal-measures have been preserved, and at what points they have been 
denuded away ; and that we cannot possibly predict. All we could say 
would be that there are considerable chances that the basin is deeper 
where it is crossed by great transverse depressions. The Straits of Dover 
are unquestionably one of these transverse depressions, and one of very 
ancient origin. Yet the data at our disposal on this point do not carry 
us back beyond the Jurassic period. Very likely the coal had a better 
chance of being preserved along the edges of this depression, but the 
statement amounts purely to a supposition. 

The conclusions which, to the best of the WTiter's belief, sum up the 
state of our knowledge on this question, and which, at any rate, lay 
down the bases of all possible discussion, are as follows : — 

The undulations of Secondary and Tertiary time have always recurred 
along the same lines, and not only do these lines follow the general 
direction and even the principal inflections of the Palaeozoic folds, but 
also (wherever study of the evidence has been possible) are proved to 
coincide exactly with the axes of those folds. This is borne out in the 
coal-field of the Nord with an exactness which extends to minute details. 

Our principle enables us to trace out the ancient folds by the mere 
study of the surface-rocks; the application of the method is attended 
with some diflBculty, partly on account of the slightness of the undulations 
which are the object of our search, partly because of the local upheavals 
and subsidences which mark the original folding. 

We may, however, aflBrm that the Dover coal-basin is distinct from 
that of the Pas-de- Calais, and that the axis of Northern Boulonnais 
(saddle of Ferques) is not the prolongation of the axis of Artois. Two 
directions are fairly presumable for the continuation of the Lens- 
Fltehinelle basin : one abuts a little north of Boulogne, near Wimille ; 
the other, keeping more to the northward, merges in the little coal-basin 
of Hardinghen, which, on the first hypothesis, would only be a branch of 
the principal basin. 

The prolongation of the axis of the Dover basin lies hidden beneath 
the waves ; and, judging from an inspection of the isobathymetrical lines 
(curves of equal depth) this axis debouches on the French coast, a little 
to the eastward of Calais. 



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126 DISCUSSION — ^THB CORRELATION OP THE COAL-FIELDS 

Mr. LuDOVic Breton (managing engineer of the works of the Sub- 
marine Railway between England and France) stated his belief that 
the Dover coal-.ba8in was independent of the other English coal-basins, 
and independent also of the French. In England there was a tendency 
to connect it with the Somerset coal-field, but he must point out that of 
the eleven fossil plants hitherto found in the Dover boring and deter- 
mined by Mr. Zeiller,* four only are common to the coal-basing of Somerset 
and Dover. These are : Nmrapteria Scheuchzeri^ N. rarinervis, Leptdo- 
dendron acideatiwi, and Sti<jmariu ficmdes^ but as the two last-named 
plants occur in Coal-measures everywhere, they cannot be used as terms 
of comparison. As to the other carbonaceous impressions of plants from 
Dover, Neuropteris tenuifolia, Maryopteris splienopferaides, Lepidost7'obu8 
vartabilis, CdlamophijUites Ompperti^ Gycloptei^is^ Lqmhdendron lycopo- 
dioideSi and Oardiocurpus, they are so far unknown in the Somersetshire 
coal-field. Nor does the Dover coal-basin resemble, in its flora, that of 
Lower Boulonnais : of the eleven fossil plants found at Dover, three only 
are found to recur in Lower Boulonnais. They are the inevitable two 
Lepidodendron aculeatum and SWjmaria firoides, the third being Lepido- 
dendron lycopodioides. The different kinds of rocks occur in very 
dissimilar proportions in the two basins thus : — 





Coal. 




Shales. 




Per Cent. 


Per Cent. 


Percent. 


Dover boring 


2-20 


55-60 


42-20 


Providence pit, Hardinghen . . 


5-86 


UOO 


80-14 



Fig. 8 is the vertical section of the Dover boring, and Fig. 9 that of the 
Providence pit, at Hardinghen. The observer is supposed to be stationed 
in England, having the Dover boring on his left, and on his right the 
Providence pit, of Hardinghen, with its coal-seams dipping 18 degs. to 
20 degs. north, and the fault which separates the Coal-measures from the 
overlying Carboniferous Limestone dipping 1 1 degs. north. The analyses 
which have been made at the National School of Mines in Paris show 
the following results for Hardinghen coal : — 

Volatile matter 35-4 to 38-6 percent. 

Fixed carbon 61*8 ,, 57*8 „ 

Ash 2-8 „ 3-6 „ 

100-0 100-0 

This is what in France is termed a " long-flame dry coal." It is of more 
recent formation than the Dover coal, where the highest seams yield no 

* Trathit. Manchester Geolg. Soc, vol. xxii., page 55. 



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OF NORTHERN FRANCE AND ROTJTHERN ENGLAlfD. 



127 



coal oontaining more than 25 per cent, of volatile matter. In a paper on 
the Carboniferous formation of Lower Boulonnais, he (Mr. Breton) had 
given his reasons for not believing that the Hardinghen coal-basin dates 
from the same period as the Pas-de-Culais coal-basin. He was just as 
incredulous with regard to the correlation of the Dover coal-basin with 
that of the Pas-de-Calais. Let ns take, for instance, a centrally-situated 
mining property, that of Bully-Grenay, where the study of Coal-measure 
fossils has been most diligently pursued. There, of 80 fossil plants 
described by Abb6 Boulay, two only are common to the Dover boring : 
they are Stigmaria Jicoides, found ,• 

*ovid#n( 



Dovvr boring pb^tm 



Pt*ovid#ncaPif 

CAW— WIMKOO* LIMkSTttHB 




everywhere in the roof and floor 
of the seams, and Lepidoden- 
dron nculeatum. Thus 78 fossil 
species are not found at Dover, 
a dissimilarity of flora which 
seemed to the speaker hardly 
capable of being exceeded. Of 
course, it was true that a careful 
search throughout the entire 
range of coal-fields of the Pas- 
de-Calais, the Xord, and Bel- 
gium, would reveal the occur- 
rence of representatives of the 
Dover coal-flora ; but one plant 
would be found at Maries, 
another at Bruay, a third at 
Noeux, and so on. That is not, 
however, the sort of occurrence 
suflicient to bring conviction to 
the mind of anyone who believes that fossil-plants constitute a highly 
important factor in the correlation of two coiil-basins. And now, how 
and where does the Dover coal-basin pass into France ? Nobody will 
deny that it does extend thither. But it is not at G nines, where two 
borings have struck Devonian rocks ; and the hypothesis of a geological 
disturbance, like that which limits to the south the Coal-measure zone 
of the Pas-de-Calais, would be the only way of accounting for Coal- 
measures being overlain by more ancient rocks. If the limestone found 
at the bottom of the Calais boring be Carboniferous, we sliould have 
to invoke the same reasons as at G nines to allow of the Dover coal- 
basin continuing across to Calais ; that is, a repetition of geological 



COALi 4 O 

FIG. 8. 



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128 DISCUSSION — ^THE COKBBLATION OP THE COAL-FIELDS 

disturbances affecting the Hardinghen coal-basin, which itself lies below 
Carboniferous Limestone, except at the eastern outcrop. In his summaiy 
of conclusions, Mr. Marcel Bertrand says that probably the axis of the 
Dover coal-basin debouches on the French coast, a Uttle to the eastward 
of Calais. This question will have to be settled by means of the borings, 
which will, no doubt, shortly be undertaken. It would be seen that in 
France they hastened slowly, when one remembered that coal was struck at 
Dover on February 15th, 1890. 

Mr. E. Keumaux (Lens) T^Tote that Mr. Bertrand's conclusions were 
not yet supported by a sufficient number of well-established facts, but 
his work was of an entirely original character, and he enunciated, with new 
arguments, a system which may well be received at some fiiture date. 

Prof. GosSELBT (Lille) wrote that Mr. Bertrand's paper was well 
worthy of careful consideration. He agreed with him as to the continuity 
of the phenomena of the folds of the earth's crust, which he demonstrated 
so clearly. But he (Prof. Gosselet) was less convinced of the absolute 
exactitude of Godwin-Austen's principle, which did not appear to him 
to be proved, that the undulations, synclinals and anticlinals, affecting 
the Secondary and Tertiary rocks are always superposed exactly over 
the folds of the PaUeozoic rocks. As to the connexion of the Dover 
coal-basin with that of the Nord (Valenciennes and Pas-de-Calais), he 
(Prof. Gosselet) did not accept Mr. Bertrand's views in their entirety. 
Two suppositions appeared possible : — (a) The Dover coal might belong 
to a basin similar to that of Warwickshire and Worcestershire, lying 
unconformably upon the extension of the Silurian schists found at 
Caffiers and Ostcnd; {b) the coal at Dover might be an extension 
of the Pas-de-Calais coal-field, whose western extension might be 
found near Bristol and in South Wales. He (Prof. Gosselet) preferred 
the second of these theories, without deciding that the first was impossible. 
This basin underwent, between Boulonnais and Dover, a cast to the north, 
similar to that which it experiences near Douai. He (Prof. Gosselet) 
considered that the Hardinghen (Boulonnais) coal did not occur (as Mr. 
Bertrand thought) in a different synclinal trough from that of the great 
Valenciennes, etc., coal-field ; but that it was a portion of the same coal- 
field thrown northward by a series of very oblique faults. 

Mr. G. C. Gbebnwell (Derby) wrote with respect to the horizontality 
of the strata bored through at Dover, that he had examined a specimen of 
the core, where passing through blue shale (now exhibited in the Natural 
History Museum), which did not seem to show horizontality of the beds. 
There are sufficient boring-tool-marks to show the vertical axis of the 



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OF NOBTHBBIir FRANCE AND SOUTHBRN ENQLAND. 129 

specimeiiy but the flat leaves of Neuropteris indicated that the plane of the 
stratum was inclined at an angle of at least 45 degs. from the horizontal. 
Mr. T. V. Holmes (Greenwich) wrote that, while recognizing with 
Mr. Bertrand a strong tendency to the recurrence of geological folds along 
the same general lines, it seemed to him that to say that "the principle 
from which Godwin- Austen proceeded is summed up in the axiom that 
recent folds are formed along the same lines as ancient folds," is decidedly 
to over-estimate his belief in their identity. Godwin- Austen pointed out 
that the Pala3ozoic ridge of the Mendip Hills was in all probability con- 
tinaous (beneath the Secondary and Tertiary rocks of South-eastern 
England) with the Palaeozoic ridge south of the coal-fields of Namur and 
Oharleroi, and that, alike in Belgium and in Somerset, the coal-fields 
were north of the Palaeozoic ridge. But he contented himself, as regarded 
South-eastern England, with saying that "we have strong a j!?wn reasons 
for supposing that the course of a band of coal-measures coincides with, 
and may some day be reached along the line of the valley of the Thames, 
while some of the deeper-seated coal, as well as certain overlying and 
limited basins, may occur along beneath some of the longitudinal folds of 
the Wealden denudation."* This reference to the "deeper-seated coal" 
arose from his belief, when the paper was written (1855), that the coal-field 
of Namur was not on the same geological horizon as that of Hardinghen in 
Boulonnais, a belief which he afterwards abandoned. However, what 
he (Mr. Holmes) wished to call attention to was that Godwin-Austen by 
no means attempted, by a detailed examination of the course of the various 
folds visible at the surface of South-eastern England, to predict the course 
of the ancient Palaeozoic ridge and its associated coal-basins beneath the 
surface. Indeed, the way in which he refers to possible coal-fields in the 
valley of the Thames, a river which, from Windsor eastwards, flows through 
the midst of a broad synclinal fold of Cretaceous and Tertiary rocks, and 
to other possible coal-fields beneath the broad anticlinal of the Weald, 
seems to imply reliance chiefly on the general direction of the Palseozoic 
ridge, and but little trust in the evidence of surface-features. Naturally, 
therefore, he confined himself to broad and general statements as to 
direction. Indeed, the uncertainty of surface-indications as guides to the 
greater or less depth of the Palaeozoic rocks under South-eastern England 
is very strikingly illustrated by the results of the deep borings in that 
region. The boring at Battle was begun in the lowest rocks visible at 
the surface east of Marlborough Downs, Salisbury Plain, and the New 
Forest, and in the centre of the great surface-anticlinal of the Weald, 
* Quarterly Journal of the Geological Society, vol. xii., page 73. 
yoi*. v.-i8n-08. ^ 



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130 DISCUSSION — ^THB CORRELATION OP THE COAL-FIELDS 

Judging, therefore, from these circumstances, it might have been antici- 
pated, on the hypothesis that the newer anticlinal was practically identical 
with the older one, that the Palaeozoic ridge would be met with in that 
locality unusually near the surface. Similarly, it might have been expected 
that the borings in and near London, at Meux's brewery, Kentish Town, 
Turnford, Wai-e, Crossness, Streatham, and Eichmond, in the broad 
synclinal fold of the London basin, would show Palseozoic rocks at a 
considerably greater depth. But, as is generally known, the results of 
these borings have lent no weight whatever to supporters of the practical 
identity of ancient and more recent geological folds. The Sub-Wealden 
boring near Battle, though begun in Upper Oolitic rocks, ended in Oxford 
Clay (Middle Oolite) at a depth of 1,905 feet. On the other hand, the 
borings in the synclinal of the London basin, after passing through an 
average thickness of about 1,000 feet of Cretaceous and Tertiary beds, all 
ended in either Paleozoic or Triassic rocks at that or a slightly greater 
depth, the latter appearing either directly beneath the Cretaceous beds, or, 
in two cases, beneath thicknesses of 87 feet and 64 feet of Oolites in addi- 
tion. Thus, under the broad synclinal of the London basin, the Palaeozoic 
rocks are unusually near the surface, and the Oolites, which would be 
naturally expected beneath the Cretaceous beds, were almost entirely absent. 
While, in the centre of the Weald anticlinal, the enormous thickness of 
the Upper and Middle Oolites alone prevented the boring, though almost 
twice the depth of the average of those near London, from showing the 
full thickness of the Oolite formation. Nothing can more strikingly 
illustrate the danger of undue reliance on surface-features as an index to 
the position of much more ancient subterannean folds in South-eastern 
England, whatever may be the case in northern France. In conclusion, 
it occurred to the speaker to remark that, judging of the unseen parts of 
the Palaeozoic ridge and its associated coal-basins from what is visible, 
alike in England and in Belgium, one must not expect regularity either 
in the breadth or direction of the ridge, or in the size and occurrence of 
the coal-basins. For in the Palaeozoic ridge one had an ancient rugged 
mountain-chain, while the coal-fields probably vary both in size and in 
their relations to this chain, at least as much as do those of Bristol, the 
Forest of Dean, and South Wales with the Mendip Hills and their 
continuation in Pembrokeshire and Glamorganshire. 

Prof. Boyd-Dawkins, F.R.S. (Manchester), said the Institution was to 
be congratulated on having received from one of the greatest authorities on 
mining in France a paper based upon his own special knowledge of that 
part of the country which joined immediately to our own, and he, too, felt 
to some extent fortunate because Mr. Bertrand's conclusion as regards the 



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OF NOBTHEBN YRASCE AKD SOUTHEBN ENGLAKB. 181 

coal-field of Dover and SomerBetshire was one which entirely coincided 
with the view he communicated to the Royal Institution in 1890.* In 
that paper he called attention to the fact that in all probability the Dover 
coal-field continued to Calais and extended indefinitely eastward in the 
same direction. He would like to say a few words before discussing the 
question of folds, as to Godwin- Austen's meaning of the axis or ridge of 
Artois. He did not mean one anticlinal, but the complicated series of 
anticlinals and synclinals which with the faults form a line of weakness 
in the earth's crast, and which he traced all the way from the south of 
Ireland, through South Wales to the region of the Mendip Hills, and as 
far to the east as the region of Westphalia, and he pointed out that all 
along the great ridge of Artois, as he called it, workable coal-fields were 
to be found. Then he insisted upon another thing ; he pointed out that 
this great line of weakness formed a ridge, and that that ridge formed a 
barrier against which the Secondary rocks were gradually thinned away. 
He also pointed out that this great barrier was marked by the line of the 
North Downs and by the arch which is represented by the Chalk of 
Wiltshire. Now, it seemed to him (Prof. Boyd-Dawkins) that in both 
these points Godwin-Austen's conclusions were amply and utterly proved 
to be true. Godwin- Austen's ideas were those which led in the first place 
to that very interesting boring at Netherfield which revealed the enormous 
thickness of the Secondary rocks — they were 1,905 feet, and when he said 
that the boring ended merely in the Oxford Clay he was giving proof 
that the Palaeozoic rocks in that region (far away, as they would remem- 
ber, from Godwin-Austen's line or ridge) were deeply buried beneath 
the Secondary rocks. The minimum depth at which the old Palaeozoic 
plateau was buried in that region was certainly not less than 2,000 feet, 
and it might be considerably more than double that. Supposing they 
now turned to the second result of Godwin-Austen's principle. In 1886, 
as the result of Godwin-Austen's work and principles, he (Prof. Boyd- 
Dawkins) was led to select the site of the present boring at Dover — the 
boring which had been carried on by Sir Edward Watkin under his 
advice, and under the able management of Mr. Brady, and which had also 
at a later time the advantage of the advice and consultation of some of 
the leaders of mining in this country : he alluded more particularly to 
Mr. McMurtrie and some other gentlemen who were now present. 
What then should he say regarding the Dover boring as to the thickness 
of the Jurassic rocks in that place ? We find that instead of 1,906 feet 
(the thickness of the Jurassic rocks in the district of Battle) they were 

* Proe. Royal Ifut.f 1890, vol. xiii., page 175, and Trans, Manchester Geol, Soc,^ 
1891, vol. XX., page 502, and 1892, vol. xxi., page 456. 



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132 DISCUSSION — THE COKRBLATION OP THE COAL-FIELDS 

here Bomething over 600 feet ; in other words, the Secondary rocks, as 
they go from the direction of Hastings towards Dover, gradually thin off 
as Godwin- Austen said they would against this great ridge. The coal was 
struck exactly where Godwin-Austen said it was likely, where, by the 
thinning of these Secondary beds against the ridge in question, the coal 
existed at a workable depth beneath the surface. With regard to " work- 
able depth " — 1,100 feet as they all knew was not very much, and when 
they knew that the Coal-measures were struck at 1,118 feet below 
sea-water mark, they were of course dealing with Coal-measures which 
were well within the limit. The extent of Godwin- Austen's ridge of the 
Coal-measures somewhere along the line of the North Downs and the &ct 
that the Secondaiy rocks thinned off against that ridge were proved 
beyond all doubt by the boring near Battle and the boring at Dover 
carried on by the Channel Tunnel Company. The boring at Calais was 
made in 1850, and, according to the account which was given a few years 
afterwards by Mr. Prestwich and that given by some other eminent 
geologists, the Coal-measures were discovered and struck at a depth close 
to the depth at which they were struck at Dover. In the present paper, 
Mr. Bertrand follows Mr. Gosselet in saying that there was no evidence 
that the Coal-measures were struck in that boring ; unfortunately, the 
specimens were lost after the Paris Exhibition, but happily Mr. Prestwich, 
who examined them with the late !^lie de Beaumont, had no doubt 
that the specimens in question implied the existence of Coal-measures at 
Calais. The Calais boring then proved most satisfactorily the continua- 
tion of the South-eastern coal-field, as they might call it, from Dover and 
right under the channel in the direction of Calais. It was an undoubted 
fact that when they had great lines of disturbance, which were lines of 
weakness in the earth's crust, they would have the rocks which were 
folded afterwards and which rest upon those rocks tending to be crumpled 
parallel to the lines of fold. He ventured to think Mr. Bertrand had not 
clearly proved — at all events he would like to have a great deal more 
evidence on the point before accepting it— that the folds in the superficial 
rocks, taking it as a general principle, were identical in superposition with 
the folds which existed in the Palaeozoic rocks ; and still less so when he 
knew that the Coal-measures and the Upper Carboniferous rocks which 
formed the ancient floor beneath the Secondary rocks were for the most 
part planed off to one dead level, composed of anticlines and synclines, 
and constituting practically one horizontal sunken plateau. He could not 
recognize that superficial folds on the surface gave any clue whatever to 
those foldings which were presented by the rocks which were buried and 
had been eroded and water-worn. This was not Godwin-Austen's view. 



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OF NORTHERN FRANCE AND SOUTHERN ENGLAND. 133 

All he inBisted on was the existence of the general principle. The line in 
question consisted not of one anticlinal or synclinal but it related to that 
grand series of plicated anticlinals and synclinals and folded rocks which 
constituted the axis of Artois, and which Godwin-Austen traced on the 
one hand from the Mendip region, under the Chalk in the North Downs 
until ultimately it reappeared in its proper position to the south of 
the Franco-Belgian coal-fields. He did not wish to detain them longer 
than he could help in discussing this veiy interesting and important 
paper, but if they took the principles of the folds laid down in it and 
applied them to the well-ascertained facts in this country he was bound 
to say these principles did not work so far as he knew the rocks in the 
south of England. There were no less than four axes, anticlinals and 
synclinals, massed together under the name of the axis of the Mendip Hills. 
Was there any indication in the rocks which cover up the eastern flanks of 
the Mendip Hills and cover the coal-fields too of any corresponding folds, 
anticlines, synclines, and others? He had no hesitation whatever in 
saying as far as he knew that country (and he knew it very minutely) 
that it was impossible to trace the complicated anticlines and synclines by 
corresponding folds in the rocks which cover them. Take another case. 
The area of London was a synclinal area ; according to Mr. Bertrand's 
principle they ought to have a syncline corresponding with the synclinal 
area down below. What did they find ? There was clear and absolute 
proof from the district of Richmond, from the series of observations taken 
as far north as Ware, that there were older rocks than Carboniferous, that 
is to say Devonian and Upper Silurian rocks. It was clear, therefore, that 
it was not a synclinal but an anticlinal fold, an anticlinal from which the 
Carboniferous rocks had been denuded, and in which merely the axis of 
older rocks were shown. With regard to these crucial points, they must 
have more evidence of the truth of the coincidence of the folds in the 
newer rocks with those of the older before they could apply them for 
practical purposes in this country. It remams now to consider the present 
position of the (luestiou of the buried coal-fields in southern England : — 

(1) Tlie coal discovered at Dover was a good blazing coal, with lozenge- 
shaped cleat (the result of slight deformation by pressure of the original 
cubes). It was distributed in nine seams over 1 foot in thickness, of which 
the thickest was 4 feet, and presenting a total thickness of 20 feet 11 inches. 

(2) These seams were associated with sandstones and shales dipping at an 
angle of 1 in 28, and constituting measures 1,109 feet thick. This gentle 
dip may, as he (Mr. Boyd-Dawkins) had pointed out in 1892, be the result 
of the boring l)eing in the centre of a syncline. (3) The few casts of 
Calamites, of Lepidodendra and ferns were too imperfect to allow of the 



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134 DISCUSSION— THE COBRBLATION OF THE COAL-FIELDS 

horizon of the coals being identified by the fossil flora. We still lacked the 
evidence necessary to establish the zones of vegetable life in the British coal- 
fields which would admit of such an identification. (4) The south-eastern 
coal-field to which they belong was, in his opinion, in the saine relation 
to the ridge of Artois as the Somerset, South Wales, and Franco-Belgian 
coal-fields, on the northern side. It was probably continued eastwards 
under the Channel, in the direction of Calais and Belgium, and its westward 
prolongation in the direction of Somersetshire remains to be proved, along 
Godwin- Austen's line of the North Downs. (5) It was probably bounded 
to the south by the highly-faulted and folded older rocks, possibly con- 
taining locally small troughs of Coal-measures similar to those of Boulounais, 
which pass southwards under increasing thicknesses of Jurassic rocks as at 
Battle in Sussex, and in the district south of the Mendip Hills. In this 
latter district there were a series of large east-and-west faults which threw 
down the Coal-measures, to the south, and which were represented by the 
smaller faults traversing the newer rocks. (6) The Silurian strata proved 
under the newer rocks at Ostend, and the Devonian and Silurian rocks 
struck in the lower valley of the Thames and along a line reaching from 
Richmond to the south, to Ware on the north, show that the northern 
boundary of the south-eastern coal-field is to be sought somewhere south 
of a line connecting Ostend with Richmond. (7) The plateau of buried 
rocks, including Coal-measures, lies in south-eastern England in the area 
of Dover and London, at about the same horizon from 900 to 1,100 feet 
below. Ordnance datum, and the anticlines and synclines of which it is 
composed can only be ascertained by experiment. It was simply a question 
of fishing. (8) The discovery of the south-eastern coal-field is of great 
economic importance. It offers the long-wanted base-line for further 
exploration. It will probably, in the near future, convert the chalk cliffs 
into "studies in black and white," and turn the purely agricultural 
districts of Kent and Sussex into centres of busy industry like Li^ge. 
Down to the days of Elizabeth the sound of the forge echoed through the 
Weald of Kent and Sussex, and enormous cinder-heaps were formed, now 
grass-grown, or covered with trees. It will be a curious result of the 
whirligig of time, if, with coal for smelting near at hand, the old iron 
industry, which dates back as far as Roman times, should, through this 
discovery, again be revived. 

Mr. P. S. Reid (London) said, having made two journeys to the 
Continent with the late Mr. Godwin-Austen, and having also been 
accompanied by the late Prof. Bonamy Price on one of them, who was 
strongly impressed at that time by the opinions of Sir Roderick Murchison 
as to the futiUty of searching for coal in South-eastern England, he might 



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OF NOETHBRN FRANCE AND SOUTHERN ENGLAND. 185 

have some slight claim to a knowledge of Mr. Godwin-Austen^s idea on 
the subject. He never, however, understood Mr. Godwin- Austen's theory to 
hinge upon a supposed series of folds more than chat these so-called folds 
were evidences of seismic changes on the earth's surface, which produced 
the curious form of coal-fields extending as it does from Dortmund in 
Prussia into Belgium and thence into France, passing under the Straits of 
Dover and ending in the Badstock and Bristol coal-fields. In short, if he 
understood anything of Mr. Godwin-Austen's ideas on this point, it was 
clear to him that these coal-formations were originally horizontal, and that 
the curious state of squeeze, overlap, and disruption was entirely brought 
about by overwhelming seismic changes on the earth's surface. He might 
add that Mr. Price, impressed no doubt by a knowledge of Sir Roderick 
Murchison's views on this subject, did his best during a week's journey on 
the Continent to turn Mr. Godwin- Austen's views into ridicule, prompted 
by his intimate knowledge of his old college friend, who took all his banter 
in very good part. He never heard Mr. Godwin-Austen allude to the 
existence of an arch in the Oolitic or Cretaceous rocks, further than to 
express an opinion that the Coal-measures would be found below them, in 
the shape of a crushed basin unknown in the North of England, and 
dissimilar to any other of the coal-basins of England, with the exception 
of that of Radstock. The revelations of the coal-field at Dover, as shown 
by the boring carried on by the Channel Tunnel Company, do not show 
us such a crushed basin, and the first touch of the Coal-measures there, as 
well as the latest boring, whose cores may be seen at South Kensington, 
reveal the fact of an almost horizontal coal-field, with a complete absence 
of crush. This would, in his (Mr. Reid's) opinion, resemble more the 
existence of a coal-field similar to that of Yorkshire or Durham, than any 
accideuted coal-field like that of Radstock or the Continental coal areas 
extending from Calais to Dortmund. The Coal-measures at Dover were 
cut into at 1,113 feet from the surface, and the first coal-seam was passed 
through at 1,189 feet, and from this point eleven seams were passed 
through terminating in the lowest at a depth of 2,181 feet, which, he 
estimated from information he possesses, would be found with a thickness 
of 4 feet of excellent coal. Of the other seams, he considered nine of them 
would be found workable with varying qualities of coal, but all of a class 
that would bear comparison with any of the seams of the known English 
coal-fields. This boring would have ended with a diameter of 7 inches had 
it not been tormented at the depth of 1,900 feet by a plastic clay which was 
melted by the attrition of the water in the hole until they were forced to 
diminish the size of the cores to 4 inches at the lower part of the hole, as 
the difficulty of cleaning out was great, and the cost of re-tubing the hole 



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186 DISCUSSION — THE COBRBLATION OP THE COAL-FIELDS 

looked formidable. He considered the discussion of Mr. Bertrand's paper 
at the present time, dealing as it did with much nebulous matter, as 
premature, and liable to misconception in an Institution like this, and 
certainly would prefer its being adjourned to such time as more solid 
information could be brought forward. 

Mr. James McMubtrib (Bath) said the views first expressed by Dr. 
Buckland, and afterwards by Mr. Godwin-Austen, Prof. Prestwich, and 
others, had been abundantly verified, and some amongst our own members 
who had expressed similar views long ago, were also entitled to be con- 
gratulated on the results. He would especially mention one name in 
connexion with this, one of the oldest members and one of the late 
Presidents of the North of England Institute of Mining and Mechanical 
Engineers, Mr. 6. C. Greenwell, who in 1862, on his return from an 
inspection of the Belgian coal-field with Mr. Dickinson (H.M. Inspector 
of Mines), expressed a decided view in favour of the theory held by these 
other geologists^ and, putting a pencil mark on a map in his possession 
immediately opposite Dover, said to him personally, *'If ever coal is 
found in the South of England, that is where it will be found." It was 
remarkable that this opinion expressed in 1862 should have been so abund- 
antly verified by the results of the Dover boring, and he thought Mr. 
Greenwell, too, was to be congratulated on the result. Having him- 
self visited the Belgian coal-field, he was interested in this question, and 
was glad last year to have the opportunity of inspecting in London and 
Dover the whole of the cores, with which he was much impressed, for the 
discovery of nine seams had proved the reality of that coal-field, and this 
was still further emphasized by the discovery of a thicker seam — 4 feet in 
thickness, which undoubtedly proved the existence of a valuable coal- 
field there. The promoters were also to be congratulated on the almost 
perfect horizontality of the strata, for, having examined core after core, 
he was unable to detect any evidence whatever of confusion or distortion. 
There seemed to be no evidence of folds amongst the strata, the beds were 
as level as the leaves of a book, a point of great importance to the future 
working of that coal-field. Although he had carefully perused Mr. 
Bertrand's paper, he was unable to grasp all the points raised. It would 
require a lengthened consideration of the contour-lines and levels on both 
sides of the Channel before the members could form an adequate opinion 
as to the facts brought before them. Two leading ideas seemed to be 
brought forward in the paper, one was the principle of the recurrence in 
the Secondary rocks of the folds and other effects which existed in the 
older rocks beneath ; the second point appeared to be that the Belgian 
coal-field in coming westward divided into a series of troughs or basins 



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OP NOETHBRN FRANCE AND SOUTHJBRN ENGLAND. 187 

separated from each other by elevations of the older rocks. Taking the 
first of these points, there could be no doubt that Mr. Godwin-Austen's 
main theory was quite correct, viz., that the elevations of the older rocks 
which existed -on the southern side of the South Wales and Somerset 
basin and on the southern side of the Belgian and French coal-fields were 
identical, and he thought Mr. Oodwin-Austen's view was also correct (in 
a broad and general way) that the North Downs might be a later exten- 
sion of the same range. But when they came to trace, by the more 
minute folds which Mr. Beitrand in his paper had endeavoured to make 
out, the history of the older rocks which lay beneath, they would agree with 
Prof. Boyd-Dawkins, and say that the case had not been made out to 
their satisfaction, and that they should reserve their opinion until the 
matter had been further investigated. There could be no doubt that 
ancient disturbances did act along certain lines at recurring periods; 
evidence of this was shown in the lines of disturbances which had come 
down to modem times. These seemed to follow in successive periods, and 
to indicate, as Prof. Boyd-Dawkins had said, a line of weakness in the 
earth's crust, and it was reasonable to expect that in the Secondary rocks 
of the South of England similar results might be found. In the French 
and Belgian coal-fields there was reason to believe that there were ancient 
elevations which preceded the Coal-measures ; that in the Silurian and 
Devonian periods elevations took place which had the effect of creating a 
series of basins in which the Coal-measures were afterwards deposited uncon- 
formably ; so that the upheavals which elevated the Coal-measures was not 
the first which had occurred but the second, the second being coincident with 
the first. And it would be not unnatural that in the Secondary period, in a 
lesser degree possibly, there might be some evidence of a third elevation, 
but speaking from the Somersetshire side of the question, he was bound 
to say they had little evidence, if any, in that direction. Having read 
this paper, he had turned his thoughts to the Mendip Hills, where 
evidence might be souglit for, but only two indications occurred to his 
mind. One existed on the northern flank of the Mendip Hills, in a ridge 
known locally as Chew Down. Here there was a fold in the l^ias exactly 
parallel with the Mendip Hills, probably indicating that there was some 
continuation of the folding action in the Secondary period. The other 
instance was at Old Down, where there was a synclinal fold which 
Prof. Boyd-Dawkins was well acquainted with, and which he (Mr. 
McMurtrie) believed to be approximately parallel to the Mendip Hills, 
and this also seemed to indicate the same thing. But when they turned 
attention to Frome, where the Mendip Hills were lost beneath the 
Secondary rocks, there was no evidence of folding whatever, the ridge 



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138 DISCUSSION— THE CORRELATION OF THE COAL-FIELDS 

simply passing beneath the other Secondary rocks. There was one effect 
produced by this ancient range which ought to be mentioned :— At the 
close of the Coal-measures the ridge of the Mendip Hills had existed 
apparently as a ridge partially covered with water, some of its higher 
points being out of the water ; but for the most part it had existed as 
a sunken ridge, the water rising high up the hill-sides ; and these 
Secondary rocks appeared to have been deposited round the edges of the 
hills. On some of the lower elevations thin deposits were found of New 
Red Sandstone at one point, Lias at another, and at Frome a thin 
coating of Oolite, the great mass of the Secondary deposits being to the 
north and south of that range, but there was no folding. He doubted 
very much when they examined deposits as recent as Chalk, in the 
neighbourhood of Calais and Dover, whether they would find any 
physical results of the existence of that deep-seated ridge. With regard 
to the second theory advanced by Mr. Bertrand, that the Belgian coal- 
field was split up into a series of basins extending westward towards 
Calais, he (Mr. McMurtrie) had turned attention to the Somerset field to 
see if there were any indications of similar results, and he was bound to 
say that at present he knew of none. If the Belgian coal-field broke 
westward into a series of parallel basins one would expect to find traces 
of simDar action in Somerset, and this might be found in other coal-fields 
lying to the south of the Mendip Hills ; there was reason to believe such 
might be found, but at present they did not know of any. The Coal- 
measures on the northern flank of the Mendip Hills were so fully 
developed, and the seams so thick and numerous, that they presented no 
indication that they were the southern boundary of the Coal-measures ; 
on the contrary, they were such as to lead them to hope for a continuance 
of those measures on the southern side of the hirs. It was said that a 
small piece of coal was once found m the neighbourhood of Wells, but it 
was not conclusively proved, and all they cguld say at present was that 
there was no geological reason why a repetition of the field should not be 
found there. He would congratulate the Institution on having such a 
valuable paper, which, however they might look at it or differ from it, 
contained a large amount of infonnation which would lead to good 
results hereafter. 

Prof. Hull said he had read the paper, and was glad to find this 
subject (with which Mr. Godwin-Austen's name was so closely connected) 
was treated from the French side of the Channel. The author had grasped 
Mr. Godwin-Austen's ideas very clearly, and endeavoured to illustrate them 
by reference to the structure of the country on both sides of the English 
Channel. He fully concurred that the lines, the great axes of folding, of 



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OF NORTHERN FRANCE AND SOUTHERN ENGLAND. 189 

different periodfl had been often repeated and particularly in the case of 
the Cretaceous period, the flexures which undoubtedly, in the South of 
England, followed the lines that were originally marked out (so to speak) 
at the close of the Carboniferous period, probably of the Permian; 
because he held that the east-and-west foldings were of pre-Permian age, 
that is to say, were immediately produced at the close of the Carbonifer- 
ous period and followed by a vast amount of denudation before the 
Permian rocks were deposited ; while the north-and-south foldings 
(which traverse the great South Wales and Somersetshire and the Forest 
of Dean coal districts, causing them to assume basin-shaped forms) was 
of later date — after the Permian period and before the Trias. He 
thought they had now sufficient ground for believing that the Palaeozoic 
rocks below the London basin and southward really followed each other 
in successive order. He had felt recently very strongly that we ought to 
have all the borings that had been made, and that were being made from 
time to time, in the east and south-east of England laid down on maps, 
so far as they threw light on the structure of the pre-Secondary rocks. 
So that ultimately we, or those who succeed us, may be able to construct 
a geological map of the south, south-east and centre of England, such as 
would appear if all the Secondary rocks were stripped away. 

The President said their thanks were especially due to Mr. Bertrand 
for having written this paper, and he was sure the discussion had been 
such that all of them must have enjoyed it. Although they were not 
probably quite alive to the whole of the details, he thought it must have 
been very interesting to them. He was afraid the state of the coal 
trade did not warrant more capital being brought into it. Posterity was 
to be congratulated, and he thought a time would come when coal in the 
South of England would be worked ; but its value had yet to be tested. 
A seam of coal, 4 feet in thickness was, as they all knew, as regards 
thickness, very valuable ; in fact they were working seams not more than 
half that thickness at present, consequently a 4 feet seam of coal, of the 
quality that had been stated, was a very valuable find. He thought they 
had a good deal more to learn with reference to the coal of the South of 
England, and that this paper would materially assist them. He proposed 
a very hearty vote of thanks to Mr. Bertrand for his very valuable paper. 

Mr. McMurtrie expressed his pleasure in seconding the motion, 
which was carried with acclamation. 

Mr. Marcel Bertrand wrote that he wished in the first place to 
thank the Federated Institution of Mining Engineers for the insertion of 
his paper in their Transactions^ and to thank the members present at the 



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140 DISCUSSION — ^THB CORRELATION OF THE COAL-FIELDS 

meeting for their kindly and oonrteoos reception of his oommnnication. 
He considered it a great honour that his views should have been the 
subject of a discussion so brilliant and searching. He was by no means 
surprised at the objections which had been raised, or at the reservations 
which had been made with regard to his conclusions. He remembered the 
words of Lyell in the Antiquity of Man to the effect that these are difficult 
subjects, concerning which no man should write unless he is prepared to 
make mistakes sometimes. He would wish, however, mainly for the 
purpose of defining his views, to answer two of the objections which were 
raised by Mr. McMurtrie and Prof. Boyd-Dawkins. Firstly, as regards 
the fan, opening westwards, formed by the various secondary synclinal 
folds of the Valenciennes coal-basin (the most northerly folds ceasing to 
contain coal before the more southerly fold of the Pas de Calais). If that 
view were recognized as correct, it would in no wise imply that a similar 
phenomenon should recur symmetrically in Somersetshire. And after all 
it is a matter of merely secondary importance. The same thing cannot be 
asserted of the objection founded on the London basin, which is a synclinal 
basin superposed upon an anticlinal ridge of the older strata. But in his 
(Mr. Bertraud's) view the contradiction is more apparent than real, for 
the London Tertiary basin is not a single synclinal fold, but a composite 
depression, succeeded longitudinally by a whole series of folds. Doubtless 
these folds are so slight that it is quite possible to deny their existence, 
and in any case one can hardly plot them out definitely. And yet it is 
just these folds that one ought to know and to discuss for the purpose of 
applying the principle as he (Mr. Bertrand) understands it. Similarly the 
subjacent Palaeozoic ridge is a composite one, not a single anticlinal fold ; 
the Secondary folds which furrow it no doubt correspond to the folds (more 
or less obliterated) of the Cretaceous and Tertiary strata, independently of 
the fact that the former underwent altogether a movement of uplift after 
Palaeozoic times, while the latter underwent a movement of depression 
after Tertiary times. If these vertical movements (compared elsewhere 
with secular oscillations) be not carefully separated from folding move- 
ments, the principle that has been enunciated becomes indefensible, and 
its untrustworthiness can then be demonstrated by appealing to scores of 
examples. It is just herein that he (Mr. Bertrand) has modified, as was 
so well said by Messrs. P. S. Eeid and McMurtrie, the theory first set forth 
by Godwin-Austen : he (Mr. Bertrand) claims that it is not the movements 
as a whole, of the earth's crust, movements which vary unceasingly and yet 
are always complex, which are similarly reproduced along the same lines, 
but only the folding movements. The fold, which is the tectonic unity 



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OF NOKTHBBN PRANCE AlO) SOUTHERN ENGLAND. 141 

reoognized in mountain chains, would then have just as great an indica- 
tory value in plain country where its prominence, however, is often slight, 
as where it is masked by other movements. If, instead of considering an 
individual fold, we consider a group of folds, forming a basin such as the 
London basin or a dome such as the Weald, we shall of course find that 
our rule will not work, because, despite the coincidence of each several 
pair of unities, the subjacent group taken as a whole does not correspond 
to the superjacent group as a whole. If instead of Ariadne's thread for a 
clue, you take a rope to guide you, 'twill scarce help you out of the 
labyrinth. 



Sir Archibald Gbikib read the following paper on "The Work of 
the Geological Survey": — 



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142 THE WORK OF THB GEOLOGICAL SURVEY. 



THE WORK OF THE GEOLOGICAL SURVEY. 



By Sib ARCHIBALD GBIKIE, F.U.S., Dibectob-General. 



Before geology became organized into a definite branch of science, 
men had begun to perceive that one fundamental requisite, as a ground- 
work for the study of the rocks of the earth's crust, alike in their 
theoretical and industrial aspects, lay in the delineation of the respective 
areas of these rocks upon maps. At first the maps so constructed were 
merely rough representations of the general distribution of the mineral 
masses. They were mineralogical, or as they were called then, geognostical, 
that is, they only aimed at an indication of the relative positions of the 
rocks at the surface. They made no attempt to show the structure and 
sequence of the various formations. It was not until the time of 
"William Smith that geology was supplied with the means of determining 
the true succession of the stratified rocks, apart from mere lithological 
characters which had previously been the only guide. Well may we 
look back upon that great pioneer as the father of English geology. In 
every department of the science we may trace the direct or indirect 
influence of his fruitful labours. But in no branch of investigation has 
this influence been more profound than in geological map-making, and in 
the assistance which geological maps have furnished to the onward pro- 
gress of the science. The earliest truly geological map, as distinguished 
from its geognostical or mineralogical predecessors, was the famous map 
of England, laboriously constructed by Smith himself after years of patient 
investigation, and published in 1815-1819. The appearance of this map 
marks an epoch in the history of the science. It showed for the first time 
how the successive stratified formations of the earth's crust could be 
recognized and traced, apart altogether from their varying mineral 
characters, and how the geological structure of one country could be 
logically compared with that of other countries. In fulness, accuracy, 
and artistic delineation, an enormous advance has been made during the 
last three generations in the construction of geological maps, but the 
initial impetus of this advance must unquestionably be traced to the early 
surveys of William Smith. 



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THE WORK OP THE GEOLOGICAL SURVEY. 148 

We are all more or less familiar with the important share which this 
country has taken in the development of modem geology. It is perhaps 
not so generally recognized how much the science has been aided here by 
the early delineation of the geological features of these islands upon maps. 
What William Smith did for England and Wales, Macculloch did for 
Scotland, and Griffith for Ireland. Macculloch's map, published in 
1832, though less original than Smith's, and bearing more evident trace 
of the influence of the older geognostical school of observers, was a 
remarkable achievement for a single observer, in a region so complicated in 
its geological structure and, in the early decades of this century, so 
difficult to traverse. Griffith had the advantage of coming later into the 
field, when geological methods of observation had made considerable 
progress. His great map of Ireland, published in 1846, is consequently 
much more modem in its treatment of the subject. It will ever remain a 
monument of extraordinary industry, sagacious observation, and felicitous 
inference, employed in the investigation of a country where, save in a few 
detached areas, he was practically the first great pioneer. 

But it was not only in the British Isles that the necessity for geological 
maps was recognized as a basis for scientific progress in the investigation 
of the earth's history. I need only refer to the first sketch of a geological 
map of France, Belgium, etc., by J. d'Omalius d'Halloy (1822), to the 
excellent map of France by DufWnoy and !^lie de Beaumont, 1840-42, 
and to the early maps of Desmarest, Dumont, Von Dechen, Naumann, 
and other cartographers in different parts of Europe. 

Even the best of these early maps were confessedly mere outlines. 
Their scale was small, and their topography often meagre and even 
inaccurate. For geological research they were inadequate, while for 
industrial purposes they were entirely insufficient and even in some degree 
misleading. The connexion between geological investigation and many 
practical affairs in daily life had now begun to be perceived. In this 
country the first geologist who devoted himself to the development of this 
connexion was Henry Thomas de la Beche — a name which we regard with 
pride and affection as that of one of the greatest leaders of the science 
whom Britain has produced. Having begun to study the geological 
stracture of Devon, Cornwall, and West Somerset, he became greatly 
interested in the many problems which the rocks of that region present. 
He saw that an accurate delineation of the courses of the mineral veins, 
elvans, and faidts through the masses of killas and granite could not but 
be of the utmost service in the prosecution of the mineral industry on 
which the prosperity of the country so largely depended. Accordingly, 



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144 THE WORE OF THE GEOLOaiOAL BUBVEY. 

supplying himself with the Ordnance maps on the scale of 1 inch to a 
mile, he began, with a few assistants and at his own charges, to map the 
details of the geology. Impressed with the national importance of the 
work which he had undertaken, he made application to the Government of 
the day for assistance and recognition. In the year 1882 he obtained a 
small Parliamentary grant in aid, and in successive years he succeeded in 
so influencing the official mind in favour of the views which he advocated 
that in the end he had the gratification of establishing a Geological 
Survey of the kingdom as one of the scientific undertakings of the nation, 
with an affiliated School of Mines, a Museum of Practical Geology, and a 
Mining Record Office. His aim was to conduct the whole establishment 
on the basis of strictly scientific investigation, but to afford in every 
possible direction all the aid which geology could furnish to mining 
industry, engineering works, agricultural progress, and other practical 
affairs. This design, broadly conceived by him, was efficiently carried 
into execution. The Geological Survey which he founded grew under 
his fostering care and that of his successors, and became the parent and 
model of other national surveys which have since been organized so 
plentifully both in the Old World and in the New. 

Without attempting to give, even in outline, a history of the progress 
of our Geological Survey, I propose to lay before you on the present 
occasion some details as to the nature and extent of the work that is now 
carried on by the Survey. The designs so ably planned by Sir Henry 
de la Beche were extended by his successor. Sir Roderick Murchison, and 
were further improved by my predecessor. Sir Andrew Ramsay. Since 
my own appointment as Director-General in 1881, 1 have been enabled to 
introduce other modifications that tend to still greater efficiency. But 
essentially the organization and methods remain as they were planned by 
the first founder of the service. 

The Geological Survey is now divided into three distinct branches, one 
for each of the three kingdoms, but united and kept in organic connexion 
under one Director-General. Each staff has its separate organization, but its 
members may be interchanged. It consists of two grades : (a) district- 
surveyors, geologists, and assistant-geologists, whose chief duty, under the 
superintendence of their director, is the preparation of the maps, sections, 
and memoirs, and (b) collectors who, under the supervision of the other 
officers, search for fossils and collect specimens of minerals and rocks for 
determination and for exhibition in the museums. There is an office and 
likewise a museum in London, Edinburgh, and Dublin. Each branch 
has thus its own headquarters with a small resident staff, the head office 



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THE WOBK OP THE GBOLOaiCAL SUBVBT. 145 

for the whole Survey being the establiahment at Jermyn Street. The 
total strength of the service in the United Kingdom, including the offices 
engaged in museum work, is at present 60. As the duties are practically 
the same in each branch of the Survey, I shall treat the whole as one 
service and describe its work under the following heads : — 1st, mapping ; 
2nd, petrographical determination ; drd, palaeontological determination ; 
4th, the collecting of rocks, minerals, and fossils ; 5th, the preparation of 
maps, sections, and memoirs for publication ; 6th, museum work ; 7th, 
general administration ; and 8th, relations of the service to other Govern- 
ment departments and to the general public, as regards the furnishing of 
geological information. 

I. MAPPiNa. 

The first and most important duty of the Survey is to map in detaU 
the geological structure of the country. When this task was first under- 
taken by De la Beche and his associates they employed the Ordnance 
Survey maps on the scale of 1 inch to a mile (^^^inr) which had then been 
published for Cornwall and Devon. These early Ordnance sheets, however, 
were imperfect and incorrect in their topography, having been among the 
first undertakings of the Ordnance Survey, before methods of surveying 
had been brought to the perfection that has since been attained. The 
connexion between the Geological and the Ordnance Surveys was at first 
so intimate that the former was instituted as a subsidiary branch of the 
latter. The geologists belonged to the " Ordnance Geological Survey," 
and though they were never under military orders they wore a uniform. 
The only surviving relics of that connexion are some of the waistcoat 
buttons, which on festive occasions continued to be worn after the rest of 
the raiment had disappeared. But from the first, and up to the present 
day, the Ordnance maps have been the basis on which all the geological 
work has been conducted. We have heard much in the last few years of 
the inaccuracies and imperfections of these maps. But the experience of 
the Geological Survey does not bear out this charge. I do not suppose 
that the maps have ever been put to a severer test than by the oflicers of 
the Geological Survey, who have carried them into every nook and corner 
of the country, from coast-line to mountain-top, and have checked them 
in many ways while fixing the positions of geological lines. It is, of 
course, admitted that the old 1 inch maps are unequal in value, and 
frequently imperfect or even inaccurate in their topography. But since 
the Ordnance Survey was plotted on a large scale, the accuracy attained 
has been so great and so invariable as to fill my colleagues and myself 

VOL. ▼— lew-B. 10 



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146 TH£ WORK OF THE GEOLOOIOAL SURVBT. 

with admiration. It is on these most excellent mape that onr geological 
lines are traced npon the ground, and on which they are ultimately 
engraved and published. So that although the old outward bond of 
connexion between the two surveys has long been severed, the relationship 
between them remains as intimate and cordial as it has ever been. 

All the mapping of the Geological Survey is now conducted upon the 
Ordnance maps on the scale of 6 inches to 1 mile (njTTTr)- These maps 
were not available in England and Wales until about two-thirds of the 
country had been surveyed geologically, and it was only in the northern 
counties that they could be adopted. In Ireland, however, and in Scotland, 
they were obtainable from the commencement of the geological operations, 
so that the whole of the work has been conducted with them as a basis. It 
is impossible to over-estimate the gain, both in completeness and accuracy, 
from the substitution of a large-scale map in the general investigation of 
a complicated geological region. For example, no more admirable piece 
of geological mapping had ever been achieved when the Geological Survey 
maps of North Wales, by Ramsay and his colleagues, were published. 
That difficult region was surveyed on the 1 inch scale, and excellent 
though the work still is, it is far inferior to what the same band of 
intrepid mountaineers could have accomplished had they had the good 
fortune to be furnished with 6 inches maps. Occasionally, when the 
structure becomes excessively complicated and when its details require to 
be mapped out clearly to be intelligible, maps on the scale of 25 inches to 
a mile (yrxnr) ^^ rnsAe use of. Ultimately, however, all the work is 
reduced to the 1 inch scale, this being the scale on which the general 
geological map of the United Kingdom is published. 

Let me say a few words about the actual methods of geological survey- 
ing. The question is often asked of us, do we bore or dig ? and when 
we answer in the negative, an incredulous smile may often be seen on the 
face of the enquirer, who evidently at once begins to doubt the trust- 
worthiness of any surmises we may make as to what lies concealed 
beneath the surface. In reality, however, a trained geologist can generally 
teU, with a close approximation to accuracy, the character and arrangement 
of the rocks underneath his feet. There are many indications to guide him 
which do not strike the eye of the ordinary observer. So far from being 
guess-work his conclusions are often based upon such an array of observed 
facts as to be irresistible. The first experience of a recruit who joins the 
service is to be trained in the practice of searching for geological evidence. 
He soon learns how unobservantly he had walked about before, and in how 
many ways he may detect indications of how geological boundaries run, 



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THE WORK OF THB GEOLOGICAL SUEVBT. 147 

even when the rocks themselves may generally lie out of sight. He finds 
that moles and rabbits help him greatly by throwing up the snbsoD for his 
inspection. The farmer assists him as he plonghs and drains the land. 
He is even indebted now and then to the grave-digger. Every ditch 
and cutting may be made serviceable for his purposes. Wells, quarries, 
pits, railway-cuttings, in short, every natural and artificial exposure of the 
rocks or of their detritus may Aimish him with the information he 
requires. It does happen now and then that, after fairly exhausting the 
evidence, he has to confess himself puzzled. He cannot be quite sure 
how the rocks exactly lie and how his boundary-lines should be made to 
run. In such cases we have sometimes recourse in the Survey to the 
boring-rod, and by its means we have been able in one or two localities to 
prove the existence of formations of which no superficial evidence could be 
obtained. 

A member of the Geological Survey may start fully accoutred for his 
work in the field without betraying by any outward visible token what is 
his handicraft. His maps are carried in a portfolio which slips into his 
pocket or hangs by a strap inside his coat. His hammer goes into a 
sheath and belt round his waist. His clinometer, compass, notebook, lens, 
pencils, and other small items are easily stowed away among his numerous 
and capacious pockets. Thus lightly equipped he may make his way over 
any kind of ground, and can spend a long day in the prosecution of his 
work. 

Not only by minute observations of superficial detritus but by measure- 
ments of the dip of rocks, where these are exposed at the surface, the 
observer may form tolerably accurate conceptions of the nature and 
arrangement of the rocks underneath and of the depth at which any given 
stratum may be expected to be reached. Thus in questions of water-supply 
he may, from such superficial observations, predict with some confidence 
the distance to which a boring must be sunk before a certain water-bearing 
stratum will be reached. 

(a) Drift Survey. — Geology had made considerable progress in the 
study of the solid rocks before much attention was paid to the looser 
superficial deposits. The Geological Survey in this respect followed the 
general rule, and for many years made no systematic attempt to represent 
the numerous and often complex accumulations of superficial materials. 
Some of these indeed were shown on the maps, such as tracts of blown sand 
and river-alluvium. But it must be remembered that in the south- 
western counties, where the Geological Survey began its work, and in those 



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148 THE WORK OF THB GBOLOGICAL SUBYBY. 

wheie for many sabseqaent years this work was contmued, saperficial 
deposits are of such trifling extent and importance that they were not 
nnnatnrally ignored. Only after most of the southern half of England 
had been completed was it determined to map the surface-deposits with 
as much care and detail as had been expended on the older formations 
lying beneath them. It had been discovered that this course was 
necessary both on scientific and practical grounds. In the first place, 
these superficial accumulations contained the records of the later geological 
vicissitudes of Britain, and were beginning to reveal a story of the pro- 
f oundest interest, inasmuch as it dovetaUed with the history of the human 
occupation of the country. In the second place, it was recognized that 
in many various ways these surface-deposits had a direct and vital 
influence upon the welfare of the population. In agriculture, in water- 
supply, in questions of drainage, and of the location of dwellings, it was 
seen that a knowledge of the soils and subsoils, and of the formations 
from which these are derived, was of the utmost practical importance. It 
was therefore determined that thenceforth the Geological Survey should not 
only pourtray the lineaments of the solid earth, but trace out the drifts 
and other surface-deposits which, like a garment, overspread and conceal 
them. It was impossible at first to go back over the ground where the 
surface-geology had been omitted. But it was arranged that when the 
whole country had once been mapped those tracts should be re-examined 
wherein the superficial deposits had not been surveyed. And, in the mean- 
time, over all new areas the survey was made complete by the tracing out 
both of the surface-deposits and of the older rocks below them. 

No one who has not given some personal study to the complicated 
details of surface-geology can realize the amount of labour which the 
mapping of them often involves. The distinctions between the various 
superficial deposits, though real, are sometimes slight, and as sections are 
frequently few and wide apart, and the deposits so often occur in irregular 
patches, the ground has to be traversed with a detailed sci*utiny which is 
generally not required for the older rocks underneath. Viewed broadly, 
the superficial accumulations are grouped and mapped by the Survey in 
two leading series. First come those which have resulted from the decay 
of rocks in situ^ and then those of which the materials have been trans- 
ported into their present positions. 

1. The first of these two series, in so far at least as it is capable of 
being mapped, is mainly confined to the extreme southern fringe of 
England. All over the three kingdoms^ indeed, the weathering of rocks 



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IHB WOR^ OF THE GKOLOGICAL StJEVBY. 149 

has for ages been in progress, and here and there, especially in the upland 
apd monntainoas districts, accnmnlations of rotted rock may be observed 
at the foot of the crags and on the slopes. Bat what can there be 
observed is only what has accnmnlated since the last glaciers and ice-sheets 
scraped the loose detritus off the surface to form parts of the great group 
of glacial deposits. South of a line, however, drawn from the mouth of 
the Severn to the mouth of the Thames, this country seems never to have 
^ain under a mantle of moving land-ice, nor beneath a sea covered with 
drifting ice, though fragmentary sheets of old marine gravels cap many 
of the plateaux and traces of probable ice-transport are found on the south 
coast. The surface in this southern tract has thus been left undisturbed 
for a great length of time. Its rocks have slowly decayed and their dibris 
have gradually accumulated above them, with only such slight transport as 
may have been due to the washing of rain and the sifting of wind. We 
see the results of this prolonged waste in the bhck-earths, clay-with- 
flints, and other deposits, that form so marked a feature on the Chalk 
Downs. From the Chalk districts westward across the Jurassic, Devonian, 
and older formations, even to the farthest headlands of Cornwall, every 
rock is more or less buried under a covering or "head" of its own 
decayed material. Sometimes, as on the Oolitic strata of Dorset or the 
killas of Cornwall, this upper decayed layer may be traced as a yellow or 
orange band, varying from a few inches to many feet in thickness, con- 
forming to the shape of the surface, and presenting a singular contrast to 
the black horizontal shales of the one coast and the purple vertical slates 
of the other. In the interior, where natural or artificial exposures of the 
rock are sometimes scarce, the spread of this mantle of disintegrated 
material is a serious impediment to the mapping of what lies underneath it. 

2. But it is the second or transported series of surface-deposits which 
chiefly engages the attention of the Survey. In mapping it an effort has 
been made to discriminate each of its members, to trace out their relations 
to each other, and to ascertain the connected geological history of which 
they .are the records. At the same time, regard has been had to the 
practical applications of the enquiry, the connexion between soil And sub- 
soils has been kept in view, pervious and impervious deposits have been 
distinguished, and an endeavour has been made to collect and embody on 
the maps as much information as possible regarding the practical bearings 
of the surfece-geology. 

As an illustration of the detail into which the mapping in this depart- 
ment has been carried, I may mention that under the single term 



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150 tHE WOBK OF THE (^fiOLOGIOAL SUBVSt. 

"alluvium" we now discriminate and indicate by separate signs and 
colours a large number of distinct deposits. Thus, there is a group of 
freshwater alluvia, beginning with the present flood-plains of the rivers 
and rising by successive terraces to the highest and oldest fluviatile plat- 
forms. Deposits of peat are separately traced, and tracts of blown sand 
are likewise mapped. Then there is another series, of marine alluvia 
ranging in position and age from the mud of modem estuaries and the 
sands of flat shores exposed at low water, through a succession of storm- 
beaches and raised beaches, up to the highest and most ancient marine 
terraces 100 feet or more above the present level of the sea. Begarding 
the origin of some of the high-level gravels, there is stiU much uncer- 
tainty, but the Survey has taken the first necessary step for their ultimate 
explanation by carefully tracing their distribution on the ground. 

But the most abundant and complex group of superficial deposits is 
4)hat which may be classed under the old name of Glacial Drifts. These 
have been mapped by the Survey in detail, and much of the progress of 
glacial geology in this country has been due to the sedulous investigation 
thus required. The ice-strise on the solid rocks have been observed 
over so much of the country, that maps may now be constructed to show 
both the march of the main ice-sheets and the position of the later valley- 
glaciers. The various boulder-clays have been mapped, likewise the 
«ands and gravels, the esker-drifts, the marine shelly-clays, and the 
distribution of erratic blocks. A vast amount of information has thus 
been collected regarding the history of the Ice Age in most parts of the 
country. Even in the southern or non-glaciated fringe which I have 
already referred to, one of the members of the staff has been able to 
.detect interesting evidence that though beyond the limits of the northern 
ice-sheets, this southern tract nevertheless had its frozen soil and its rafts 
of coast-ice. In the north of Scotland proofs have been obtained of the 
long-lingering of the ice-fields in that region ; while in all the mountainous 
districts the gradual retreat of the valley-glaciers, as the climate grew 
milder, has been shown by mapping the successive crescents of moraines, 
one behind the other, up to the very base of the crags that supplied their 
materiaL 

The survey of the superficial deposits thus combines a wealth of 
geological interest with a great deal of practical value. The geologist 
may find in it the solution of some problems and the presentation of 
many more. While the farmer, the water-engineer, the builder, and the 
sanitary inspector may each in turn gain some practical information from 
it for their guidance. 



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Xttfi WOBK OF THB GEOLOGICAL SUEVBY. 151 

(b) Solid Oeohgy Swrvey, — By way of distinction, the mapping of 
the formations of eveiy age that lie beneath the recent superficial deposits 
is known as the survey of the " solid geology.'* The object in this part 
of the work is to represent on the maps the exact area which every 
formation or group of rocks occupies at the surface, together with all 
indications that can be obtained of its structure, such as its variations of 
inclination, its changes of lithological character, and the dislocations by 
which its outcrop is affected. While the basis of the work is rigorously 
geological, an effort is made to ascertain and record any facts which may 
have an industrial bearing, such as the presence of useful minerals, or 
the depth and variations in thickness of water-bearing strata. The large 
scale on which the Survey is conducted aUows much local detail to be 
inserted on the maps both of a scientific and a practical nature. 

In those districts of the country where the rocks have long been 
well-known and where the geological structure is simple, the duties 
of the surveyor are comparatively light, though it often happens there 
that the simplicity of the solid geology is compensated for by a great com- 
plexity in the overlying " drifts.*' Yet even among formations that have 
long been familiar, the diligent surveyor may generally glean new facts, 
or be able to throw new light on fects which were already well-known. 
Thus only a few years ago, even in a formation so well worked out as the 
Chalk, one of the members of the Survey detected the existence of a 
phosphatic deposit like those which have long been worked in the Chalk of 
Belgium and France. 

It is where the rocks are varied in character and complicated in 
structure that the full working power of the Survey is called out. Take, 
for example, such a tract as that of the North-west Highlands of Scotland. 
In that region the mere physical difficulties of the ground are great. 
With a topography of exceeding ruggedness and sometimes of great 
elevation, with a climate wetter and more boisterous than almost any 
other to be met with in these islands, and with quarters often of the 
most uncomfortable description, the geological surveyor needs all his 
enthusiasm and ardour to carry him bravely through these preliminary 
obstacles. But when he comes to unravel the structure of the rocks 
he finds it almost incredibly complex. Day after day he may be seen 
traversing the same face of cliff, creeping from crag to crag, hammer in 
hand, heedless of the eagle that sweeps out from its nest above him or 
the red deer that breaks from its covert in the rocks below, his eye intent 
on the &ce of each scar and cleft as he pauses to take his measurements or 
. SQt down his notes on map and notebook. He encounters varieties of 



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152 THE WOBK OF THE GEOLOGICAL SUBYEY. 

rock which he may be unable to identify by any of the simple tests that 
can be applied in the field. He takes chips of these home with him, 
and if they still offer diflBculties he sends Ihem up to the ofiBce, where 
they are cut into thin slices and examined with the microscope, or are 
chemically analysed, and a report embodying the results of the examination 
is returned to him for his guidance, while he may himself study the 
slides and verify or check the observations which the petrographer has 
inade upon them. Again, he may detect in other rocks traces of organic 
remains, the importance of which he at once perceives. Such specimens 
as he can himself collect are sent up to the head ofSce for determination 
by the palaeontologists, and upon their decision may depend the name 
to be assigned to the f ossilif erous rock and the colour and sign whereby it 
is to be designated on the published maps. 

The complication of the "solid geology" in these north-western 
regions is enough to tax to the utmost the capacity and the energy of the 
surveyor. But he has besides all this to keep his eye ever open to all 
the varying problems presented by the superficial deposits. The ice-striae 
on the rocks, the scratched stones high on the mountain-sides that mark 
where the till once lay, the varieties of boulder-clay, the sand and gravel 
«skers, the scattered erratic blocks and the detection of their probable 
sources of origin, the moraine mounds fringing or filling the bottom of 
the glens, the sheets of flow-peat and the rugged peaty mantle that hangs 
down from the cols and smoother ridges, the recent alluvia and the 
successive stream-terraces, the lines of raised beach and the estuarine 
sUts — all these and more must be noted by him as he moves along and 
must be duly chronicled on his map and among his notes. 

It is obvious that the progress of a surveyor in such ground cannot be 
rapid. If the work is worth doing at all, it should be well done, and if 
well done, it must be done slowly and carefully. It is evident also that 
the total area surveyed in a year, if given in square miles, affords no 
guidance whatever as to the amount of labour involved. There may be a 
hundredfold more exertion, physical and mental, required to complete a 
single square mile in some districts than to fill in ten square miles in 
others. It is customary in the service to estimate not only the area 
annually sm'veyed by each officer in square miles, but also the number of 
miles of boundary-line which he has traced. The ratio between these two 
figures affords some measure, though an imperfect one, of the comparative 
complexity or simplicity of the work. In simple ground a surveyor need 
have no difficulty in mapping from 70 to 100 square miles in a year, 
each square mile including from 3 to 6 linear miles of boundary. But in 



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THE WOllK OF THE GEOLOGICAL SUHVET. 158 

more ragged and difficult districts it is often impossible to accomplish 
half of that amount of area. In these cases, however, the ratio between 
area and boundary-lines usually rises to a high proportion. Thus last 
year, in Argyllshire, the average number of linear miles of boundary-lines 
was as much in one district as 17 miles in every square mile surveyed. 

In mining districts an endeavour is made to express on the maps 
the positions of the outcrops of all seams and lodes, the line of every 
important fault and dyke, with the place of such faults at the surface, 
and where they cut diflFerent seams underground. For the information 
necessary to record these data we are mainly indebted to the owners and 
lessees of the mines and pits, who, as a rule, most generously give us every 
assistance. Details as far as possible are inserted on the 6 inches Ordnance 
sheets. Oopies are taken of borings and pit-sections, and notes are made 
regarding variations in the character of the seams or lodes from one part 
of a mineral field to another. At the same time the district is surveyed in 
the usual way, and by exhausting the surface-evidence the surveyor is not 
infrequently able to supply important additional information beyond what 
can be obtained from the mining-plans. 

It is the necessary fate of all geological maps to become antiquated. 
For, in the first place, the science is continually advancing, and the systems 
of arrangement of the rocks of the earth's crust are undergoing constant 
improvement, so that the methods of mapping which satisfied all the 
requirements of science thirty years ago are found to be susceptible of 
modification now. In the second place, in the progress of civilization, 
new openings are continually being made in the ground, wells, roads, 
drains, railways, and buildings are being constructed, whereby fresh light 
is obtained as to the rocks below. Geological lines which were traced with 
imperfect evidence can thus be corrected, and new lines which perhaps 
were not suspected can be inserted. If this kind of obsoleteness overtakes 
geological maps even where only superficial openings are concerned, still 
more does it affect those which depict the structure of mineral fields 
still actively worked. The geological maps of Devon, Cornwall, and 
South Wales, made more than half a century ago by De la Beche and 
his associates were for their time admirable in conception and excellent in 
execution. Nothing approaching to them in merit had then been pro- 
duced in any part of the world. But the mineral industry of the country 
has not been standing stiU all these years. Enormous progress has been 
made in working the ores of the western counties, and in developing the 
;.great South Welsh coal-field. Yet the maps remain as they were 



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154 TfiB WO&t Ot 1?HB GEOLOGICAL SUBVlElf. 

originally published. The Geological Survey has of itself no power to 
undertake revision, and much as we would like to see all the mineral fields 
re-surveyed and brought up to date, we cannot go faster than Parliament 
will sanction or the Treasury will authorize. Two years ago, in response 
to an important memorial from South Wales, we received instructions to 
commence the re-survey of that coal-field, and the work is now in active 
progress. I trust the day may not be distant when similar revisions will 
be made of the other mineral-fields which were surveyed many years ago 
on imperfect 1 inch maps. 

The re-surveys of the mineral districts can now be carried out on 
the 6 inches scale with a completeness and accuracy unattainable when the 
original surveys on the 1 inch scale were made. In some cases the maps 
of mining districts have been published on the 6 inches scale, but where 
the sale is likely to be small, instead of incurring the heavy expense of 
engraving the 6 inches sheets, we issue manuscript copies of these sheets at 
the cost of manual transcription. As an illustration of the kind of work 
undertaken by the Survey in the mining districts, I may refer to the Maps, 
Sections, and Memoir of the Yorkshire coal-field. There is no reason, 
save one of expense, why all the mining districts of the country should 
not be similarly treated. 

Though systematic re-surveys are not undertaken by the Survey 
without express sanction, it is customary to make minor corrections which 
from time to time may be required in the published maps. Those 
counties in the south and south-west of England of which the superficial 
deposits were not originally mapped are now undergoing revision for 
the "Drift Survey," and advantage is taken of the re-examination of the 
ground for the insertion of the surface-geology to make any needful altera- 
tion in the lines of the solid geology. 

II. Petrographical Woek. 

In the earlier days of the Geological Survey each member of the staff 
determined for himself, by such tests as he could apply, the various rocks 
encountered by him in the field. Only in rare cases were chemical 
analyses made for him. The study of rocks had fallen into neglect in this 
country, being eclipsed by the greater attraction of the study of fossils. 
The introduction of the microscope into geological investigation has, 
however, changed this apathy into active interest. It is now recognized 
that apart from mere questions of nomenclature, rocks contain materials 
for the solution of some of the most important problems in physical 
geology. Accordingly, microscopic enquiry has in recent years been 



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.<rHB WORK OF THE GBOLOGlCAL SURVEY. 166 

organized as one of the branches of the Geological Survey, and now affords 
constant and material aid in the progress of the mapping. Chemical 
analyses are likewise made, so as to afford all available information as to 
the composition of the mineral masses encountered in the field. 

When an officer engaged in mapping meets with rocks which present 
difficulties, either as to their classification or as to their bearings on the 
stmcture of the ground, he takes specimens of them which he numbers 
consecutively and sends up to the petrographer at the office, who enters 
them in a book under the name of that officer, and keeps a record of the 
destination of each. Those specimens which are selected to be sliced are 
numbered consecutively in the order in which they are cut, and are 
entered in books kept for the purpose. When they have been micro- 
scopically studied, described, and named, they are again entered in two 
distinct catalogues, one of which is arranged according to the sheets of 
the 1 inch map and the other accordiug to petrographical types. Every 
sliced specimen is thus entered four times, and every specimen sent up for 
examination (whether sliced or not) can at once be found. A report is 
made out by the petrographer and sent back to the officer, who is thus put 
in possession of all the details which can be furnished to him regarding 
the rocks about which he needed assistance. In many cases the thin 
slices are also sent to the surveyor, who often spends his evenings in their 
study. 

The original specimens from which the thin slides have been prepared 
are carefully kept in cabinets, so that if any accident should befall a slide 
a new slice can at once be cut. The mounted slides are arranged in 
separate cabinets. A large number of such slides have now been accumu- 
lated. From Scotland alone upwards of 5,000 have been determined, and 
are ready for reference at any moment. 

But besides assisting the field-work, the petrographers are engaged in 
determinations required for the arrangement of rock-specimens in the 
museums at Jermyn Street, Edinburgh, and Dublin. The collectors are 
employed under the supervision of the surveying officers to make 
illustrative series of specunens of the rocks of each district. These are 
sent up to the office for examination and for insertion in the museum. 
In the course of the research thus imposed on them, the petrogi-aphers 
are from time to time enabled to make important original contributions 
to petrographical science. Moreover, they confer in the field with the 
officers who are engaged in mapping, and sometimes in concert with them 
make observations which are embodied in conjoint memoirs on the 
geology of the several districts. 



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166 THE WOBK OP TEt GEOLOGICAL SUEVElT. 

III. PAL.ffi!ONTOLOGI0AL WORK. 

In a oonntiy where the geological formations are to a large extent 
fossiliferons, it is necessary to pay close attention to the organic remains 
found in the rocks, to collect specimens of them, to determine these 
specifically, and to regulate thereby the geological boundary-lines upon 
the maps. The duty of examining and reporting upon the fossils is 
entrusted to the palasontologists, who occasionally visit the field, but are 
mainly engaged at the museums. With reference to the exigencies of field- 
work a somewhat similar system is followed with regard to fossil evidence 
as in the case of the petrography, though the same minute detail is not 
necessary. The ofScer, when in doubt about any species, the names of 
which are needful in separating formations and drawing their mutual 
boundary-lines, collects specimens of them and sends them up to the office 
for identification. They are compared by the palaeontologist with 
published descriptions and named specimens, and a list of their specific 
names (as far as they can be made out) is supplied to the surveyor. 

Besides such specimens as may require to be identified in the course 
of the mapping, full collections from the formations of each important 
district are made by the collectors under the guidance of the officers by 
whom the district has been surveyed. Every specimen is numbered and 
registered in the collector's book, so that its source and destination can at 
once be found. Lists of the fossils are drawn up by the palaeontologists 
for insertion in the published memoirs. A selection of the best specimens 
is placed in the cases, drawers, or cabinets of the Museum. Fortunately 
in the case of the palaeontologists also, though much of their work is 
necessarily of a routine official chaiucter, opportunities are afforded to 
them of making interesting and important additions to palaeontological 
science. It was from this department of the Survey that Edward Forbes 
produced some of his best work, that Salter made his fame as a 
palaeontologist, and that Professor Huxley enriched geological literature 
with his memoirs on Silurian Crustacea, Old Red Sandstone fishes, and 
Triassic reptiles. Within the last few months fresh distinction has been 
won by one of the staff of the same department from the investigation 
and restoration of a series of remarkable reptiles from the Elgin Sand- 
stones. 

IV. Collecting Wobk. 

From what I have already said it will be seen that systematic 
collection of the minerals, rocks, and fossils of the country is an essential 
part of the operations of the Geological Survey, and is made to aid the 
progress of the mapping and the completion of the illustrations of British 



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THB WOBK OF THE GlBOTiOGICAL SUEVBT. 157 

geology in the musemns. Each branch of the Survey has its collector, 
who moves from district to district as his services are required. When 
he b^ins work in any area, he is supplied with a map on which the field- 
officer who surveyed it has marked every locality that should be searched, 
and also with a list of these localities, giving local details as to the rocks 
to be specially examined and the kind of specimens to be looked for and 
collected. When necessary the surveyor accompanies the collector to the 
ground and starts him on his duties. Every specimen which the collector 
sends up to the offioe has a number affixed to it, and is entered in the lists, 
which are also at the same time transmitted to headquarters. The 
specimens are then unpacked and treated by the palesontologists or 
petrographers, as the case may be, in the manner already indicated. 

V. Preparation op Maps, Sections, and Memoirs for 
Publication. 

The results obtained by the CJeological Survey are made public in 
three forms : Maps, Sections, and Memoirs, to which may be added the 
arrangement of specimens in the three museums, with their diagrams, 
handbooks, and other explanatory matter, and also the original papers, 
which lying often beyond the scope of the Survey's publications, are 
prepared by members of the staff and, with the consent of the Director- 
General, are communicated by them to scientific societies or journals. 

(a) Maps. — Every surveying officer is responsible for keeping his 
6 inches field-maps inked-in and coloured-up, so that if required to be 
exchanged with his colleagues they shall be clear and intelligible. He is 
likewise required to prepare duplicate copies of these field-maps, which 
when completed, are transmitted to the office and are kept there for con- 
sultation by the public. 

As I have already stated, 6 inches maps of some of the mineral-fields 
have been published. These have been prepared by the officers who 
surveyed them, the geological work being put on a dry impression from 
the plate of the Ordnance map, which is then sent to the Ordnance Office 
to be transferred to an electrotype of the plate. In a few cases, also, maps 
on this scale, where the geology is of special interest or complexity, have 
been prepared and published. But for the country at large it is not 
desirable to publish maps on so large a scale as that of 6 inches to a mile. 
Over all the counties which have been surveyed on that scale, MS. copies 
of the 6 inches maps can be obtained by the public, at the mere cost of 
manual transcription from the duplicate copies retained in the office. 



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158 THB WOEK OF THE GEOLOGICAL BTTRVET. 

The work Burveyed by an officer on the 6 inches scale is reduced by him 
npon a dry impression of the 1 inch Ordnance map. A single 1 inch 
sheet may comprise the work of half a dozen surveyors, and in that case 
the sheet is passed from one to another, each adding his own share. The 
completed dry proof is then checked at the office and is sent to the 
Ordnance Survey to be engraved on an electrotype copperplate specially 
prepared for the purpose from the original Ordnance plate. After the 
final corrections have been made in the engraved map and the scheme of 
signs and colours has been engraved on the margin, a copy of this map is 
coloured as it is to appear on publication, each surveyor again taking 
the portion for which he is personally responsible. The scrutiny involved 
in this process serves generally to detect any errors that may have 
previously escaped notice. This original coloured copy remains as the 
standard to which all subsequent copies of the same edition of the map 
are made to conform. 

When finally checked and approved, the original coloured copy is sent 
to the colourists, who colour all the maps by hand, the work being done 
by women. Experiments were tried some years ago as to the feasibility 
of producing the Geological Survey maps by colour-printing. But with 
our system of engraving it was found impossible at the Ordnance Survey 
Office to ensure sufficiently accurate registration, and there was the further 
practical difficulty that so large an impression of each sheet would require 
to be printed off that a large stock would remain on hand, and new 
editions and alterations of the maps would be impracticable for many 
years. The original system has therefore been retained. It has this 
great advantage, that by keeping the supply of copies of each sheet just 
sufficient to meet the demand of the public, we are enabled to make any 
alteration of a map which from time to time may be found to be 
necessary, without the loss involved in cancelling a large stock of copies. 

Some idea may be formed of the nature of the colouring work of the 
Survey maps from the fact that upwards of 180 different tints and com- 
binations are employed to denote the various kinds of rocks separately 
discriminated on the maps. It is difficult to find colours distinct from 
each other, yet harmonious, and that will not fade on exposure. To guard 
as far as possible against the risk of fading, every colour is also distin- 
guished by its own symbol, which is legibly engraved where the colour 
occurs on the map. 

Two editions of the maps of England and Wales are now issued for 
those districts of which the Drift survey has been completed. One of 
these editions shows all the superficial deposits, and only so much of the 



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THE WOBK OP THE GEOLOGICAL SUBVBT. 159 

underlying formationB as lies bare at the sarface. The other edition 
presents the underlying formations as these would appear if the superficial 
aocumulations could be stripped ofiF. Each of these editions has its 
value for special purposes. In all questions of sanitation, water-supply, 
agriculture, and building, it is obviously the Drift edition that should be 
consulted, while, on the other hand, where the information desired has 
reference to what lies deeper beneath the surface, as in the sinking of 
deep wells and mines, it is the Solid edition that will be most usually 
consulted. The difference between the two is merely one of colouring, 
for they are printed from the same copperplate, and as fai* as the 
engraving goes are exact duplicates. 

The prices of the maps are regulated by H.M. Stationery Office, and 
are fixed according to the amount of colouring work upon them. In 
England and Wales, full sheets usually range from ds. to 8s. 6d. and 
quarter-sheets from Is. 6d. to 8s. In Scotland and Ireland, the sizes of 
the maps are different, but their prices are calculated on the same scale, 
being in Scotland from 4s. to 6s., and in Ireland (where the sheets are 
similar in size to the English quarter-sheets) from Is. 6d. to 8s. In some 
cases the price at which a map is sold is less than the cost of colouring, 
but it is estimated that the excess of selling price beyond that cost in 
other cases will compensate for this loss. 

The total number of 6 inches maps published by the Geological 
Survey up to the present time is for England and Wales, 217 sheets; 
Scotland, 180 sheets; Ireland, 10 sheets. The number of 1 inch whole- 
sheets and quarter-sheets published for England and Wales amounts to 
258 ; 142 of these are as yet published only as " solid " maps ; 89 are 
issued in two editions, "solid" and "drift;" of 28 only the "drift" 
edition is published. Four quarter-sheets of the map of England yet 
remain to be published, but will be issued this year. The number of 
sheets published of Scotland is 48, and of Ireland 205. The whole of 
Ireland has been completed and published. Every effort is now being 
made to complete at as early a date as possible the survey of Scotland, 
but the extraordinary complication of the geological structure of the 
Highlands, being far greater than was ever anticipated, renders the 
progress less rapid than could be wished. 

The desirability of having a general geological map of the country on 
a smaller scale than that of 1 inch to a mile has long been recognized. 
When the mapping of England was completed, advantage was taken of the 
existence of an index Ordnance Survey map on the scale of 4 miles to 
an inch. This map, based on the old 1 inch maps, had been laid aside 



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160 THE WORK OF THE GEOLOGICAL 8UBVBT. 

incomplete by the Ordnance Sarvey, bnt it was likely to be bo naef ul f or 
geological parpoees that at my reqnest it was finished at Sonthampton. 
The work of the Geological Survey is now being reduced upon this map, 
of which there are in England and Wales 15 sheets. Four of these sheets 
have now been published with the geology, embracing the east of York- 
shire and the southern counties, from Essex to Torquay. Other sheets 
are in progress, and the map when completed will present at a glance a 
clear. and vivid picture of the geological structure of the whole country. 

The value of reduced index-maps for geological purposes was 
recognized long ago by the preparation of a general map of Wales. 
When the Geological Survey of the Principality was finished the whole 
work was reduced to the scale of 4 miles to an inch and engraved in 
six sheets, which include parts of the West of England. This map has 
been on sale for many years. 

(b) Sections. — A geological map can for the most part express only 
what lies at the surface, though it may afford information, more or less 
definite, as to what lies below. To supplement the map it is needful to 
construct sections to show the arrangement of the rocks beneath the 
surface. A complete and detailed map should contain sufficient data to 
allow of such sections being plotted in outline, but these details can usually 
be filled in only from the notes of the sections examined in the course 
of the mapping. Two kinds of sections are prepared and published by 
the Geological Survey — vertical and horizontal. They are drawn to 
scale, and engraved and published in sheets measuring 8 feet by 2 feet. 
But besides these, numerous measured and also diagram-sections are 
inserted into the text of the printed Memoirs. 

The Vertical Sections are drawn usually on the scale of 40 feet to 1 inch, 
and are prepared almost entirely to illustrate the succession of strata in 
the coal-fields. Each sheet generally contains more than one section. 
The materials for the plotting of these sections are sometimes obtained by 
actual measurements taken by the surveyor himself, but more commonly 
are supplied by the lessees or managers of the collieries. Sometimes 
tables of comparative sections are giveu, in illustration of variations in 
character and thickness between the seams of coal, ironstone, or limestone 
in different parts of the same mineral field. 

Occasionally, where a group of strata, though of little industrial 
importance, possesses great geological interest, a vertical section of it has 
been constructed and published in the same style as the coal-field sections, 



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THE WORK OF THE GEOLOGICAL SURVEY. 161 

In this way we have issued some useful secfcious of the Jurassic rocks in 
Eastern Yorkshire, of the Lower Lias and Khaetic rocks in the West of 
England, of the Tertiary strata in fche Isle of Wight, and of the Purbeck 
group in Dorset. 

Altogether 87 sheets of Vertical Sections have been published for the 
three kingdoms. The price of each sheet is 3s. 6d. 

The Horizontal Sections have always been an important feature in the 
work of the Geological Survey. De la Beche, recognizing the practical 
disadvantages arising from the construction of sections without any regard 
to the proportion between height and distance, instituted the practice of 
drawing them on a true scale. He adopted the scale of 6 inches to a 
mile, and invented a system of patterns for the different kinds of rock, 
which, as he was himself an artist, are appropriate and effective, for they 
represent in no small measure the general structure of the rocks. The 
institution of such sections, in lieu of the distorted diagrams too generally 
employed, was of great service to the Survey itself and also to the progress 
of geology ; for it served to correct the evil influences of distorted drawing, 
with regard not only to geological structure but to the true forms of the 
ground. 

When & line of section was chosen and drawn on the 1 inch map, it 
had to be measured on the ground with chain and theodolite. This was 
the invariable practice until the 6 inches contoured Ordnance Survey maps 
came into use. With these maps as a basis, the laborious process of 
chaining the sections is no longer required. The section-lines are drawn 
on these maps and the sections are plotted from them. The contour-lines 
and bench-marks allow the line of the surface to be traced with a close 
approximation to accuracy. But in order to ensure final correctness of 
detail, the ground is gone over with the section in hand and each little 
feature is then put in. 

The sections start from Ordnance datum (mean sea-level), but where 
the ground is low and there is consequently not room to express what is 
known of the geological structure above that datum, the lines are prolonged 
below it. The same practice is also followed in mining-districts. An effort 
is made to illustrate every great district of the country. Each geological 
formation, as it varies from one point to another, is crossed by lines of 
section, so that by comparing these the changes in that formation from 
district to district can at once be seen. The length of each section varies 
indefinitely with the nature of the ground, many of them being upwards 
of 100 miles in length. Thus a series of sections runs from Anglesey 

VOL. v.-i8oa-8. n 



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162 THE WORK OF THE GBOLOaiOAL SURVET. 

and the coast of Merionethshire, across the mountainous ground of North 
Wales, to the plains of the Midlands. Another group crosses from the 
central counties to the South Coast. A connected chain of sections 
traverses the breadth of the island from Liverpool to the coast of 
Yorkshire. 

As an illustration of the character of these sections and their useful- 
ness in correcting popular misconceptions as to geological structure and 
form of the ground, I may refer to that which runs from Leicestershire 
to Brighton and passes through London (sheet 79). What is called the 
"London basin" is by many people regarded as a deep trough of clay, 
with the Chalk rising steeply from under it both to the south and north, 
and we may see this conception embodied in actual diagrams in text- 
books and elsewhere. But in reality both the London Clay and the Chalk 
are so nearly flat that their inclination can hardly be detected except by 
careful measurement. And the section, accurately plotted from borings 
and well-sections, shows them apparently horizontal, though on further 
inspection we find that their line of junction, which is well above the 
datum-line at either end, lies some way beneath it in the centre. 

The Horizontal Sections are engraved on copper and published in 
sheets, each of which, if the ground be low, may include six lines or 
86 miles of section. The same continuous line of section may thus 
extend over several sheets. Small explanatory pamphlets are published 
with these sheets, giving general information as to their formations and 
their local peculiarities. Each sheet of horizontal sections is published 
at the price of 5s. In all 191 sheets of such sections for the United 
Kingdom have been issued. 

Besides the usual horizontal sections on the scale of 6 inches to a 
mile, occasional sections on a larger scale are prepared to illustrate the 
geological structure of particular localities. In this way the coast-line of 
Cromer and Yarmouth has been represented in detail, and its numerous 
features of geological interest have been inserted so as to exhibit a kind 
of picture of the arrangement of the strata in these changing cliffs. 
Portions of the coast-line of Dorset and of the Isle of Wight have been 
similarly treated. 

(c) Memoirs. — Obviously, in the course of a geological survey, a 
large amount of detailed information is collected which cannot find a 
place either on the Maps or the Sections. This material embraces much 
local detail and a large body of evidence which is of importance in 
general geological enquiry. It can only be properly used by being 



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THE WORK OF THE GEOLOGICAL SITBVEY. 168 

arranged, condensed, and printed. The issue of Memoirs of its work has 
been from the beginning one of the chief occupations of the Geological 
Survey of the United Kingdom. The form in which these publications 
have appeared has varied. De la Beche's plan was to publish volumes of 
General Memoirs embracing descriptions of particular regions and also 
essays on special branches of geological enquiry. His own memoir on 
the geology of Cornwall, Devon, and West Somerset is an admirable 
example of his method, and has long taken its place among the classics of 
English geology. There were practical difficulties, however, in the way 
of continuing his method when the staff increased, and the literary 
labour had to be shared by a nimiber of observers, who were, in many 
cases, more willing to wield their hammers than their j^ens. When 
Murchison succeeded to the charge of the Survey, he sought to avoid 
these difficulties by instituting the practice of accompanying every sheet 
or quarter-sheet of the 1 inch map with an explanatory pamphlet, giving 
the chief data on which the map had been constructed, with references to 
the best sections, lists of minerals and fossils, and information as to the 
geological structure of the ground. These pamphlets, containing essential 
details only, were to be eventually condensed and collated by the Local 
Director, so as to form a generalized view of each important geological 
region. This scheme was well conceived, and with some modifications 
rendei-ed necessary by the progress of the Survey, has been carried out 
ever since. It is not always possible or desirable to prepare a separate 
explanation for each sheet or quarter-sheet, for much reduplication of 
geological information would thereby be involved. Several quarter-sheets 
or sheets may be described together in a single Memoir. 

Each surveying officer is expected to contribute the account of the 
area mapped by him. Where more than one surveyor has been engaged 
on a map or district, the accounts furnished by the several officers are 
collated and edited in the office, and are published generally in paper 
wrappers and at a low price. 

Occasionally these Memoirs, when dealing with an important district, 
have been expanded beyond the limits of mere Sheet Explanations, and 
have taken the form of thick octavo volumes. Such, for instance, are the 
Memoirs on the Yorkshire Coal-field, on North Wales, on the geology of 
the Weald, on the geology of London, and on the Isle of Wight. 

The chief literary work on which the staff of the Survey are now en- 
gaged is the preparation of the General Memoirs or Monographs to which 
the Sheet Explanations were designed to be preparatory. It appeared 
to me that the most generally useful plan on which these could be 



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164 THE WORK OF THE GEOLOGICAL SURVEY. 

prepared was to make them fuudamentallj stratigraphical, in. other words, 
to devote them to a description of the various geological systems which 
are embraced within the British Isles, and to show not only what has been 
done by the Survey in each of these systems, but what has been ascertained 
by others. Each monograph should thus be a compendium of all that is 
known of its subject up to the date of its publication. The information 
obtained by the Survey in its progress is necessarily scattered through ' 
many maps, sections, and memoirs. The work of the service would be 
incomplete and diflBcult of consultation if it were left in this disseminated 
state. It needs to be gathered together, arranged, and put into connected 
form, so afl to present an intelligible account of the geology and mineral 
products of these islands. The task is a heavy one and cannot be speedily 
finished. But satisfactory progress is being made. We have published a 
Monograph on the Pliocene dei)osits of England, and two volumes of 
another on the Jurassic rocks, while a third volume is in the press. 
Another Monograph on the Cretaceous rocks is in preparation. Each 
monograph will embrace one system or group of rocks, and may consist of 
a number of volumes according to the importance of the system and the 
area which it occupies in the country. 

In the preparation of the memoirs, and for museum purposes, much 
assistance is now derived from photography. Several members of the 
staflF have become expert photographers, and a large number of views of 
geological sections, coast-cliflFs, and other natural or artificial exposures of 
rock have been taken. These serve as illustrations for the Memoirs, 
and some of them are mounted to accompany the specimens in the 
museums. 

Besides the geological Memoirs, the Survey has published a series of 
Decades of British organic remains, with plates and descriptions, also 
Monographs of important genera or groups of fossils, including Professor 
Huxley's essays on Pteryyotm^ the BelemniiidcB, the crocodiles of Elgin, 
and Mr. Newton's memoirs on Cretaceous fishes and Pliocene vertebrates. 

VI. Museum Work. 

For the complete illustration of the geology of a country it is necessary 
not only to construct geological maps and sections, and to publish 
printed descriptions, but also to collect and exhibit specimens of its 
minerals, rocks, and organic remains. Each branch of the Geological 
Survey has from the beginning kept in view the gathering of such 
specimens, and the galleries of the museums in London, Edinburgh, and 



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THE WORK OF THE GEOLOGICAL SURVEY. 165 

Dublin may be appealed to, as evidence of the manner in which the duty 
has been dischai^ed. 

The Museum in Jermyn Street is intended to be primarily illustrative 
of the minerals, rocks, and fossils of England and Wales, but as far as 
space will admit an endeavour is made to exhibit what is specially 
characteristic of the other two kingdoms. For the more detailed 
illustrations of Scottish geology recourse must be had to the Museum at 
Edinburgh, and for those of Irish geology to the Museum in Dublin. 

The portions of the Jermyn Street Museum, more especially connected 
with the work of the Survey, are the collection of fossils, the series of 
rock-specimens, and the remarkably fine and complete suite of ores and 
their accompaniments from the mines of the British Isles and those of 
the Colonies. The Museum was organized to illustrate the practical 
applications of geology. As an example of the manner in which this 
design has been carried out, I may refer to the section in which the 
connexion between raw material and finished pottery is displayed. Our 
British ceramic collection was one of the earliest formed, and is still 
perhaps the most illustrative in the country. 

The Fossils are arranged stratigraphically, and furnish the basis on 
which the Survey maps of the fossilif erous formations have been constructed. 
Every important subdivision of the Palaeozoic, Secondary, and Tertiary 
systems is represented by a full series of its characteristic fossils gathered 
from the various districts in the British Ides wherein it is developed. 
These are arranged and tableted in such a way as to be readily accessible to 
the public. Those who wish to follow out the palaeontological details 
of the Survey maps and memoirs, or to study general text-books of the 
science, have thus the fullest opportunities afforded to them. 

The palaeontologists with their assistants are continually engaged in 
arranging and retableting the collections to make room for fresh material 
received from the officers in the field, from donations or from purchase. 
Catalogues of the fossils in several departments have been prepared and 
published. 

The Rock-collections have in recent years been greatly increased and 
entirely re-arranged so as to bring them abreast of modern petrography. 
That in the Jermyn Street Museum includes a collection of rock-forming 
minerals in illustration of the characters of the more important minerals 
that enter into the composition of rocks ; a series of typical rocks, named, 
classified, and so arranged close to the eye that the visitor may have no 
difficulty in observing their general external characters ; a section devoted 
to illustrations of various geological structures such as cleavage, jointing. 



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166 THE WORK OF THE GEOLOGICAL SURVEY. 

foliation, plication, the structures of igneous rocks, the effects of contact- 
metamorphism, the markings made hj glacier ice, and the results of 
weathering in different rocks. But the chief part of the collection is a 
series of British rocks arranged in stratigraphical order from the oldest 
gneisses up to the most recent shell-sand. Not only are the sedimentary 
rocks represented in this series, but a large suite of igneous rocks is 
included, so that the student of vojcanic history may see samples of the 
lavas and tuffs which have been ejected at each of the periods of volcanic 
activity in the geological annals of Britain. Diagrams and maps are 
placed near the specimens to show the geology of the districts from which 
the latter were taken. Illustrations are likewise given of the more 
important microscopic structures met with in rocks and especially among 
those of Britain. A handbook is being prepared to this part of the 
Museum which it is hoped may prove to be a useful aid to students of 
petrography. 

The Geological Survey collections in the Museums in Edinburgh and 
Dublin are arranged on similar lines. They have been arranged strati- 
graphically to elucidate the maps, sections, and memoirs, and furnish a 
tolerably full series of specimens in illustration of the geology of each 
kingdom. A handbook for the Edinburgh gallery is published, and one 
for that of Dublin is nearly ready. 

VII. General Administration. 

I have already spoken of the organization of the staff. The collectors 
are placed under the direction of the field-oflBcers. The assistant- 
geologists are promoted, as vacancies occur, to the ranks of the geologists. 
Over these officers come the district-surveyors, who supervise the work of 
a number of geologists or assistant-geologists in a wide district. The 
district-surveyors report to their director, who takes general charge of the 
work in his own kingdom. The Director-General is the head of the whole 
organization and is responsible for its conduct. He personally visits the 
officera in the field in each of the three countries, and is thus enabled to 
see that the work is being everywhere conducted on the same lines, and 
that the results obtained harmonize. It is his duty to bring the experience 
gained in one kingdom to the elucidation of difficulties met with in 
another, and to decide from time to time when the surveyors of one branch 
may usefully be sent to see the work in progress by another branch. It 
will be understood that to these duties in the field are added the general 
correspondence and administration of the whole service, and editorial 
labour connected with the issue of the various publications. 



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DISCUSSION— THE WORK OP THE GEOLOGICAL SURVEY. 167 

VIII. Relations to other Government Departments 
AND the Public. 

From the beginning of its existence the Survey has been continually 
refeired to by all branches of the Government service for information 
regarding questions in which a knowledge of geology is required. The 
sinking of wells, the choice of sites for forts and Government buildings, 
the placing of graveyards, the selection of materials for buildings or roads, 
the nature of soils and subsoils with reference to matters of drainage — 
these and many other subjects have been reported on. Nor has the 
general public been backward in application for similar information. 
The offices of the Survey are always open, and every assistance which 
can be rendered to enquirers is placed freely at their service. 



The President said the work of the Geological Survey was one of 
special interest to mining engineers. As a body they had occasion very 
frequently to refer to their maps; and he had been struck with the 
accm'acy with which the strata and faults were mapped out. Their 
thanks were due to Sir Archibald Geikie for having, as he might say, 
revealed the secrets of their work, and he had pleasure in proposing a 
hearty vote of thanks to him. 

Prof. Hull said he was very pleased to be permitted to second the 
vote of thanks. Having been for forty years connected with the Geological 
Survey and employed upon it in England, Scotland, and Ireland, he 
appreciated the very complete outline Sir Archibald Geikie had given of 
its operations, which had recently been very largely extended. He would 
only take this opportunity of stating what, in his own opinion, was the 
work which the Survey was most urgently called upon to finish. Of course 
they all sympathized with Sir Archibald Geikie in his desire to make the 
Geological Survey of the country as complete as possible, both as regards 
the superficial deposits and the solid geology ; but when they considered 
that there were numbers of large coal-fields at present only published on 
the 1 inch scale (which was of an entirely insufficient scale to allow of the 
proper representation of the geological details), he was pretty safe, in this 
company at any rate, in stating that the most important future work for 
the Survey was the re-survey, on the 6 inches scale, of the coal-fields which 
had not been surveyed on that scale. He had had experience of the sur- 
veying of coal-fields on both scales. He surveyed Leicestershire on the 
1 inch scale, and he was perfectly aware that it required revision. It 



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168 DISCUSSION — THE WORK OF THE GEOLOGICAL SURVEY. 

was some thirty or thirty-five years since it was surveyed, and the now 
completed 6 inches Ordnance map would admit of its being undertaken 
on that scale immediately, if the oflBcers of the Survey, the number of the 
staff, were sufficient to admit of it. Sir Archibald Geikie had stated that 
the 6 inches scale survey of the great South Wales coal-field had been 
commenced and was in progress; but was the number of gentlemen 
employed on that work anything like adequate to the amount of work to 
be done? He was very fer from disparaging the work of superficial 
geology, for he was one of the first to commence it in Lancashire and 
Cheshire ; but it seemed to him that it would be more to the benefit of 
mining enterprise in this country, if some of the staff engaged on that 
work were put upon the coal-fields in order that these might be re- 
surveyed and brought up to date on the 6 inches scale. He hoped this 
suggestion would be received as not in the least degree intended to 
criticize the work of the Survey, but for those in authority, for he was 
aware it was a matter for the Treasury to supply the means ; the men 
were ready and the work would be undertaken, if the means were 
supplied for that important work. 

The vote of thanks was cordially adopted. 

Sir Archibald Geikie, in acknowledging the vote, thanked the 
members for the kind way in which they had listened to his paper. 
No one was more convinced than he of the desirability of revision, 
and no one would be more pleased to see all the coal-fields which were 
now drawn on the 1 inch re-surveyed on the 6 inches scale. It was not 
want of will on their part that had led to that work being delayed, but 
their staff was not large and there were certain definite pieces of work 
to finish. He might say that the question of the re-survey of the coal- 
fields must be determined by the Science and Art Department and the 
Treasury. The work of re-8ur\ey had been conunenced in South Wales 
owing to a very strong memorial presented to the Science and Art 
Department, and he fancied that the same procedure must be followed as 
regards the other coal-fields. 



Mr. F. G. Shaw then read the following paper on " Auriferous Con- 
glomerates of the Witwatersrandt": — 



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AURIFEROUS OONQLOMERATBS OF THE WITWATERSRANDT. 169 



AURIFEROUS CONGLOMERATES OP THE 
WITWATERSRANDT. 



By F. G. SHAW, Assoc. M. Inst. C.E. 



In ventariug to introduce certain theories as to the manner in which 
the auriferous conglomerates of the Witwatersrandt have been formed, 
and in which the gold (now found crystallized in the matrix of these 
conglomerates) has been deposited, the author hopes the members will 
grant him their indulgence should he not make his ideas sufficiently clear. 

The auriferous conglomerates of the Witwatersrandt were first worked 
in 1887, near Johannesburg in the Transvaal, 280 miles from Delagoa 
Bay, 440 miles from Durban, and 1,013 miles from Cape Town. By the 
term " Witwatersrandt conglomerates," the author alludes to those in the 
basin or syncline now being worked and forming an isolated part of the 
extensive conglomerates which are common to the sandstones of South 
Africa. The basin has an east-and-west length of about 50 miles and 
a supposed breadth of about 40 miles. The east and west ends are 
very much dislocated and faulted. The dip of these conglomerates 
appear to be governed by masses of plutonic rock, which run parallel 
to the northern and southern outcrops, and have elevated the edges of 
the beds to angles varying from 12 degs. to 60 degs. 

These seams, the author expects, will assume a horizontal position at 
comparatively short distances from the tilted outcrops, save where locally 
displaced by the intrusive masses of igneous rocks which are occasionally 
seen cropping out. Although no deep borings have proved the existence of 
these beds in the middle of the syncline, the continuity of their upturned 
edges and the regularity of their disposition, together with their known 
extent over South Africa, have impressed geologists with the conviction 
of their existence, and from 2,000 to 15,000 feet have been assumed as 
the probable depth reached by the lowest levels of this syncline 

The assumption is, that these beds of conglomerate exist over an area 
of nearly 2,000 square miles ; the regularity of their width and character 
is well proved ; and the gold up to the present time appears to be regularly 
distributed through the reefs. The importance of this field can be best 
understood by the output of gold which was for its sixth year, 1892, 
1,210,868 ounces, a greater output than any other single field of similar 



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170 AUETPBROUS CONGLOMBBATES OF THE WITWATERSRANDT. 

age in the world. During the first year of its history, 1887, this field 
produced 23,115 ounces, an amount equalled by the present weekly output. 

The conglomerates of the high veldt of South Africa, the manner in 
which they were spread over so vast an extent of country, and the pre- 
cipitation of gold in them combine to form a most interesting subject ; 
but as the main reef seam at Johannesburg, with the attendant parallel 
seams, are the most interesting from their auriferous character, this 
paper will be to a certain extent confined to them. 

Up to the present time, geologists and mining engineers have alluded 
to these conglomerates as being a sedimentary or sub-aqueous deposit and 
the gold, if they mention it at all, as being of an alluvial character and 
mechanically deposited. On this latter point Mr. C. J. Alford is perhaps 
one of the exceptions. In his book on The Geological Features of the 
Transvaal^ he says, " it appears certain that the gold was not trans- 
ported to its present position in the form of native gold by the action 
of the water ;" and again he says, " its origin is a curious and interesting 
problem." 

With reference to the conglomerates themselves, the terms "sedi- 
mentary" and "sub-aqueous" are both too indefinite, and the author 
prefers to assume that these conglomerates have been spread over the 
large surface in which they now exist and with the regularity which is 
one of their notable features, by a sea-beach action. The general 
assumption has been that they have been thus spread over the sand- 
stones in which they are conformably interbedded by the action of 
rivers, or currents in the seas, at the bottom of which they are supposed 
to have been deposited : the author will briefly discuss these two theories. 

While the action of rivers undoubtedly accounts to a great extent 
for the transportation and collection of pebbles, gravels, etc., in all 
parts of the world, no river action, that the writer has any knowledge of, 
could have so regularly spread over so large an area the seams of pebbles 
now forming these conglomerates. Even if these conglomerates existed only 
in the basin of the Witwatersrandt, a river at least 45 miles wide and of 
most peculiar character would have had to exist, which for a certain 
period would have had to deposit over its entire bed a uniform depth of 
pebbles, and then have had to deposit over the same extent a layer 
of sandstone for even a longer period, this action again being followed 
by the deposition of another layer of pebbles, then by another layer of 
sandstone, and so on, until these numberless layers of conglomerates, 
sandstones, etc., had been deposited. He knows of no analogous phe- 
nomena in any river-bed, and even were such phenomena known on a 



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AURIPBROUB OONaLOMBBATBS OF THE WITWATBRBRANDT. 171 

small scale, he can conceive of no river whose bottom would be so regular 
and uniform as the sandstones on which these conglomerates lie, especially 
when the more violent action of rivers and currents in those days are 
considered. 

These facts should dismiss the river-bed theory to the realm of 
improbability, and enable the writer to turn to the action of currents 
existing in a sea, by the aid of which pebbles brought to the edge would 
be spread evenly over an immense distance on its bottom. Such a 
regular layer of pebbles, which marine research has not yet discovered, 
would take a considerable number of years to form, and would have to 
be followed by a total cessation of pebble- deposit, a layer of sandstone- 
detritus taking its place and being deposited in the same ocean ; these 
would then have to be followed in successive order by pebble and sand- 
stone-deposits until the parallel seams now found had been formed. 
This view would necessitate a current in the ocean so regular in its 
strength and action as to carry these pebbles smoothly and evenly over 
the greater part of South Africa. No such current action is known at 
present in the ocean, the general tendency being to form banks and 
to heap up such coarse detritus as pebbles, instead of laying them 
evenly over the floor of the sea, and certainly no river flowing into 
an ocean would by its own action be able to spread its burden except in 
the vicinity of its mouth. 

The writer cannot therefore accept either of these theories as being 
reasonable and common-sense explanations of the distribution of these 
conglomerates, and he prefers to assume a progressive sea-beach action, 
which gradually spread the pebbles brought down by the rivers, etc., 
from the probably, at that time, highlands of Central Africa, over the 
then low-lying ground of the South African continent. 

In the science of geology, a thinker to be able to understand the 
difficult phenomena of the present must know the past, and from that 
knowledge he may be able to draw fair and common-sense views of 
existing phenomena, and thus knowing the present he may calculate as to 
the future. The failure of many men to grasp the theories of the 
present is due to their inability to take a retrospective view of the past : 
the only laws they know of, or will admit, are the laws governing 
the present period, and they assume that the quiet beat of every-day 
life on this staid and sober sphere has been the history of its past, not 
calculating on the turbulent energy of its youth, its bounding pulse and 
the restless energy of its younger days, or on its eventful change from a 
molten mass to its present state. 



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172 AURIFEROUS CONGLOMERATES OF THE WITWATERSRANDT. 

The author wishes therefore for a moment to go back to the time when 
our sphere was in a molten state, surrounded by an enormous thickness 
of atmosphere containing in suspension all the minerals, etc., whose 
point of evaporation was below that of the atmosphere, and gradually losing 
by radiation a portion of its heat. The formation of a film or crust would 
be the first real change on its surface, and as this crust became sufficiently 
thick to resist for some time the ebullition of the molten mass below it, the 
exterior portion would gradually become sufficiently cool to allow of the 
condensation of these various gases, minerals, etc. Many ages would pass 
during which gigantic igneous eruptions would take place, upsetting and 
distorting the existing rocks until at last the crust was continuous and 
strong enough to bear a certain superincumbent mass. As soon as the 
temperature would allow, seas would rest on this crust, eruptions would 
still take place and hydrothermal phenomena would still be common ; but 
the land would gradually begin to be of a permanent character. The 
erupted rocks would harden into hills, etc., upheavals would remain 
permanent and depressions would become greater, and the early hydro- 
thermal rocks would begin to appear, so that in course of time, low 
continents would exist as dry land, and the early sedimentary rocks, 
mudstones, shales, clays, etc., would be formed. 

As South Africa is the continent to which our attention is drawn, it 
must be assumed that its existence at this period was such as has just been 
described, the sandstones being formed with their attendant conglo- 
merates, etc., and lying horizontally a little above or below the then 
sea-level. These sandstones are found over, the whole of South Africa 
in unbroken layers on the high veldt, with traces of their existence in 
and over the low veldt, and it may be assumed that the same phenomenon 
has been responsible for their existence, and that the land about the time 
of their creation was subjected to the same laws. These sandstones were 
undoubtedly deposited under sea-action and it must be assumed that the 
then elevation of the tongue of land of South Africa was very small, and 
that it probably existed as a low land lying to the south of the tropical 
parts of Africa, whose rivers would carry down the vast amount of pebbles, 
now spread over and amongst the sandstones, by the retreating action of the 
sea-beach belonging to the same ocean which deposited the sandstones. 

The most generally-accepted theory is that the sandstones were formed 
at the bottom of the sea (which the few fossil-remains found in them 
confirm), and that the material fonning the coal-measures have been 
formed by the tropical growth of vegetation. The operations of an 
advancing sea over such low-lying lands, fed as it would be by rivers 



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AURIFEROUS CONOLOMKRATBS OF THE WITWATER8RANDT. 173 

bringing down pebble- detritus, slowly creeping over the land, followed 
by long periods of total submersion, and succeeded by a retreating sea- 
beach action, would surely be accompanied with that of settling the 
light detritus brought into it, as a sandstone- deposit, and the spreading 
out on its edges of a uniform layer of pebbles (now turned into con- 
glomerates by the subsequent infiltrating action of siliceous waters). 
In those places in which the inflowing rivers travelled through countries 
luxuriant with vegetable growth, bringing down in their waters an 
immense quantity of vegetable matter and gradually laying it down 
as a beach-line in the retreating course of the sea, making it (com- 
paratively speaking) a level bed rich with vegetable seeds and with 
every facility for bringing forth the luxuriant growth from which coal- 
seams have been derived (until the return of the again advancing sea- 
beach line many thousands of years afterwards) during which time would 
be formed one of those non-continuous lenticular betls of various horizons, 
which would under the pressure of the superincumbent mass of sandstone 
be turned into the coal and shale seams now found. 

The theory which might account for such an encroaching and 
retreating sea would probably be : gnidual elevations of tlie land, followed 
by subsequent depressions, leaving the land at one time exposed to the 
air, and afterwards covered by the ocean. Mr. S. Herbert Cox in his 
excellent book on Mines ami Minerals assumes this to have been the 
method by which the coal-seams and sandstones of Newcastle (New South 
Wales), were formed, and the theory is one easily understood and not at all 
diflBcult to accept, where the known alternate elevations and depressions of 
the land over vast continents are an accepted fact. 

Whatever was the cause. South Afriai has undoubtedly been alternately 
covered by sea- water and exposed to the atmosphere, and whether the land 
was alternately elevated and depressed, or otherwise, the sea must have 
come-and-gone and a sea-beach action been thus initiated. The appearance 
of the low veldt bears ample testimony to this fact, the mountain-ranges 
bordering the high veldt plateau of South Africa showing by their great 
denudation the erosive action of the advancing and retreating ocean, 
noticeably towards the De Kaap valley — the Makonga range being 
denuded of all its sandstones, and the overturned edges of its clays and 
quartzites, etc., on which the sandstones and conglomerates of the high 
veldt are elsewhere uncomformably deposited alone remaining; thus 
indicating great aqueous action. Mr. C. J. Alford, in his geology of the 
Transvaal, alluding to this action says, " There is every indication that at 
one time a great rush of water cleared out the De Kaap valley and carried 
away to the eastward to the Indian Sea whatever deposit once overlaid it." 



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174 AXJRIFBROtJS OOiraLOMBRATBfi OF THB WITWATBBSRANDT. 

From a residenoe there of nearly a year, and a close study, the anthor 
is inclined to think that a succession of retreating waters had performed 
the work evidently done here, as well as elsewhere on the borders of this 
high plateau and this is what we might expect as a consequence of the 
theory he has advanced. 

The next and most interesting point, is the manner in which the gold 
has been deposited in the conglomerates. The author has in his possession 
two pebbles taken from these conglomerates, which each contain a 
"colour" of metallic gold. These pebbles prove that from whatever 
source, and from whatever distance brought, some at least were gold- 
bearing; therefore, a certain amount of free gold would be mechanically 
deposited in these seams derived from the broken matrix of the more 
friable and smaller pebbles, by the grinding action of such a sea-beach as 
just described. Such a class of gold would be fairly well distributed and 
would present the rounded appearance of alluvial gold. Certain investi- 
gators at Johannesburg have microscopic slides showing such a class of 
alluvial gold ; it may therefore be taken for granted, both by assumption 
and evidence, that a certain amount of the gold now in the conglomerates 
was mechanically deposited in the way just mentioned, through dififering 
from ordinary alluvial deposits of gold in the manner in which it is spread 
through the conglomerates, in its extreme fineness, and by its not lying on 
the top or bottom of the seams, not having being carried there so much in 
the form of free gold, but deposited more or less in situ from the destruction 
of friable matrix. 

The gold, however, which is thus accounted for, forms but a small 
proportion of that carried in the reef. Mr. Alford says in his work just 
quoted, that so far as he has noticed " the gold is almost invariably in a 
more or less crystalline form, the cube in its derived forms being more or 
less detectable." He has also observed it in " the cleavage-planes of the 
pyrites in the form of minute plates and scales," and he also says " it 
appears certain that the gold was not transported to its present position 
in the form of native gold by water," and again " its origin is a curious 
and interesting problem." The result of the author's investigations has 
been to confirm those of Mr. Alford, and led him to a careful study of this 
subject, and it was only after a diligent search that he became convinced 
that the character of the matrix now holding the pebbles together had 
altered since those pebbles were originally deposited, and that the siliceous 
matrix now in the conglomerates was pseudomorphic in character. 

He is therefore inclined to believe that the original matrix, whether 
argillaceous, calcareous, felspathic etc., must have been displaced and 
and a pseudomorphic matrix carrying gold, sulphur, iron, etc., has taken 



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AURIFEROUS OONOLOMBRATES OF THE WITWATBRSRANDT. 175 

its place, and his reasons for thinking so are as follows : — In the oxidized 
as well as the unoxidized portions of these conglomerates the pebbles are 
held apart by a distinctly crystalline matrix of silica. Now, in whatever 
manner these beds were spread over so large an area, it cannot be imagined 
that the pebbles themselves sank into a firm, jelly-like mass of silica and 
remained more or less suspended in it, even if oxide of silicon ever 
assumed so consistent and glutinous a character. It is probable that an 
after-crystallization of the matrix must have taken place, together with a 
deposition of its containing minerals, and may be accounted for in the 
following manner. After the gradual laying down of these conglomerates, 
etc., intrusion of igneous rocks took place, and the vast horizontal beds of 
sandstones, etc., were in some places broken up and tilted, as in the 
Witwatersrandt basin, and so acquiring a dip would either form natural 
drains for infiltrating surface-waters or funnels through which the under- 
ground thermal-waters, laden with their store of minerals, would force their 
way upward (through the fissures dislocating these seams and caused by 
the upward action of trappean rocks) and reach the surface. In either 
case the silico% contained in these waters would crystallize in its passage 
through the conglomerates, and form the matrix that contains the minerals 
now found. It can easily be understood that an argillaceous or other 
matrix would soon be eaten away by such an action, and so the succeeding 
matrix would become pseudomOrphic in character. The contained 
minerals of such an infiltrated solution would even penetrate to some 
distance into the hanging and foot-wall of the containing sandstones, 
which, so far as the author can observe, it certainly seems to have done. 

What then is the likelihood of such solutions containing gold ? It is 
well known that gold is held in solution in salt-water at the present time, 
and probably much more existed in solution in the early days. Mr. 
Sonstadt has calculated that one ton of salt-water contains one grain, or 
about two pennyworth of gold. Taking Mr. John Murray's estimate of the 
quantity of salt-water on the earth, this will give an enormous mass of 
gold considerably over a cubic mile in bulk which was held in solution.* 
The infiltrating powers of such an overhead sea can be easily imagined, 
and a certain amount of this gold would be crystallized by chemical action 

* Mr. John Murray estimates the volume of salt water on the earth to be eqaal 
to an envelope 2 miles deep, and taking the diameter of the earth at 8,000 miles, 
this volume wiU be (8,000'» x 3*1416 x 2 = ) 402,124,800 cubic miles. If there be 1 
grain of gold in each ton of water the ratio of the weight of the gold to the weight 
of the sea-water will be as 1 to 16,680,000 ; and the ratio of the bulk of the gold to 
the bulk of the sea-water (taking the weight of gold as being 20 times heavier than 
water) will be as 1 to 313,600,000. Therefore the volume of gold in the sea-water 
will be (402,124,800 cubic miles -I- 3 13,600,000-) 1-28 cubic miles. 



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176 AURIFEROUS CONGLOMERATES OP THE WITWATBRSRAITDT. 

and to a certain extent deposited in the reef. But even if the gold held 
in solution in salt-water has not been the active means of enriching these 
and other reefs (and the author certainly believes strongly in its being 
responsible for part of the gold found in them) it must be remembered that 
after the gradual deposition of these sandstone measures, which must have 
taken immense periods of geological time, this part of the earth's crust was 
gradually elevated, as the earth cooled and contracted, until marine 
invasion was a thing of the past. Then the continuous downfalls of rain 
and great geyser visitations would form shallow thermal seas containing 
large amounts of minerals in solution, and the tilted conglomerates would 
become natural drains, carrying the waters of these seas to the fissures 
(caused by the trappean eruptions) penetrating their systems and thence 
taking it to some subterranean cavity, perhaps to be thrown up again 
bearing more mineral. The result of these streams carrying as they would 
a large amount of silicon would be the eating away of the matrix and the 
crystallization of the silicon in its place, probably filling, at different parts 
of the conglomerates, the fissures caused by the intrusive action of the 
trappean rock. 

If, on the other hand, the matrix and containing minerals were formed 
by the action of an upward flow from some thermal spring containing 
siliceous and other matters in solution, entering the conglomerates at points 
where the intrusive trappean rock had cut them off, then the remarkable 
affinity for gold which these trappean rocks seem to possess should be 
remembered. They are in this country frequently associated with gold, 
which they might communicate to, or take from, such thermal springs 
and by thus imparting the gold to the water in their vicinity, or only 
depriving it of the certain quantities of such gold, have allowed this gold 
or the residue of the gold to become crystallized in the siliceous matrix of 
the conglomerates, and thus deposited in a crystalline form in the reef. 

If the author's theory as to the pseudomorphic character of the 
matrix of the Witwatersrandt reefs be correct, it is also probable that 
reefs will be found of considerable value and extent in the vicinity of the 
intrusive dykes, which have broken through the sandstones ; and his theory 
will certainly warrant a greater faith in the continuity of gold in these 
reefs than when it was thought to be of an alluvial character and 
mechanically deposited. In the latter case it would like all alluvial 
deposits become uncertain and erratic ; while in the former case it would 
be identical with the matrix holding the pebbles together in all parts of 
the auriferous conglomerate. 



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DISCUSS rON — ^AUBIPBBOUS COKGLOMBRATBS, ETC. 177 

Mr. Edwaed Halse (London) said they were all very much indebted 
to Mr. Shaw for his very interesting paper, and he hoped he might be 
allowed to remark that such papers were of especial value because they 
promote discussion. With regard to the supposed fluviatile origin of the 
Transvaal bankets, are not certain large rivers constantly changing their 
beds, and is not this especially the case in a river- valley having a small 
fall ? The old bed of some of the larger rivers in South America, for 
instance, can be traced for a good many miles on either side of their 
present bed. It may interest members to know that an auriferous con- 
glomerate-deposit is now being formed along the bottom of the Ancobra 
river which runs into the sea a little north of Axim, on the West Coast of 
Africa. Here divers have proved that the present bottom in places is 
composed of several feet thick of a very compact mixture of small pebbles, 
broken quartz, and white sand, below which are large pebbles buried in 
auriferous whitish clay.* He (Mr. Halse) was not advocating a river 
theory for the origin of banket-formations in general, but was merely 
showing that it was not impossible. Some probably have been built up 
at the bottom of an inland lake, lagoon, or sea, or possibly at or near its 
margin by some sort of sea-beach action. It was very questionable whether 
enough was yet known about the South African bankets to say how they 
were laid down. According to one geologist! the beds have been subjected 
to great lateral pressure, folds and repetitions are very frequent ; the 
matrix shows evidence of having been squeezed round the pebbles, and 
exhibits a schistose structure, the pebbles themselves are very much 
broken, and moreover the whole of the beds have been thrust into their 
present position over the older strata below them. With regard to the 
uniformity of the conglomerates, as a matter of fact he believed that they 
were not of uniform thickness, they sometimes wedged out entirely, and in 
certain of them the pebbles were of a much larger size than in others. If 
the gold had come from sea- water containing it in solution, as suggested, 
would it not be reasonable to expect all the conglomerates of this area to 
be auriferous? but in point of fact some of them contain little or no 
gold. About two years ago, he (Mr. Halse) had an opportunity of exam- 
ining and working banket deposits on the Oold Coast of West Africa.^ 
They seem to throw some light on those of the Transvaal, although they 
are probably of much more recent age. They consisted of layers of 
talcose and titaniferous iron-sandstone, alternating with true conglomerate 
beds, also showing talc and iron-sand. The whole seam was auriferous, 

• 7}ran8, Fed, Lut.y vol. ii., page 83. f ^«^- Journ, Oeol, Soc, vol. xlviii., 
pages 404-433. J ^/'O'ns, Fed, InH., vol. ii., pages 69-84. 

VOL v.*iaw.e8. 12 



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17^ DISCU8SI0JI — ^AUBIPEROUS COSOLOIIERATRS 

but the gold increased in richnefls towards the floor of the deposit, the 
bottom layer consisting either of highly titaniferons iron-sandstone rich 
in allavial gold, or of rich banket. In the latter, as in the Transraal, the 
gold rarel J occurred in the pebbles, but was found in the cenoenting material 
or matrix, and was often collected roond the pebbles. The gold was 
mostly water-worn and in fine plates or grains, distinct crystals being rare. 
A large proportion of it too, as in Sonth Africa, occurs in an exceedingly 
fine state of division. The bankets of the West Coast of Africa exhibit 
little or DO metamorphism, faults are rare, and, although the beds dip at 
an angle of from SO degs. to nearly vertical, no volcanic rocks occur in 
the immediate vicinity to account for this tilting. The cementing-mate- 
rial was always siliceous and generally of very loose texture, crumbling 
readily in the hand, although in some parts a very hard banket is found, 
probably as hard as anything occurring in the Transvaal. He (Mr. Halse) 
would suggest that the South African bankets were once true alluvial 
conglomerates similar to those of the Gold Coast, and after consolidation 
and upheaval they were subjected to great and long-continued metamor- 
phism. Being of a porous nature, and more or less steeply inclined, they 
were subject to the same influences — chemical and other — as have helped to 
form the present structure of a true fissure-vein. A large portion of the 
alluvial gold, together with the associated iron-sand, were, it is suggested, 
dissolved and were subsequently crystallized out as auriferous iron pyrites 
and free gold. In addition a re-arrangement of the gold contents appears 
to have resulted from the leaching action, as the ore in some of the bankets 
has been found to occur in distinct shoots. Iron pyrites exists in the 
diorites of the district, and, by some, these rocks have been r^arded as the 
source of the iron pyrites in the conglomerates. The bankets have pro- 
bably been enriched by their means, but it is very questionable whether 
the whole or even the greater portion of the auriferous iron pyrites has 
come from that source. 

Mr. Walcot Gibson (London) pointed out that if the beds ever 
assumed a horizontal position within so short a distance of their outcrop, 
as stated by Mr. Shaw, it would greatly increase the value of deep- 
level properties, while those situated on the outcrop would ultimately 
loose their reefs. But it was certain that the beds never assumed a 
horizontal position, as the southernmost reefs always possess a dip not 
much less than 15 degs. to the south. The paralleb'sm of the beds as 
represented by Mr. Shaw as occurring at the Ginsberg mine was mislead- 
ing. The beds on the Randt, taken collectively, were really lenticular in 
character, as could easily be seen, as the beds are traced east and west of 



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OF THE WITWATBBSRANDT. 179 

Johannesburg. The ooontrj rock, as well as the conglomerates, contained 
iron pyrites ; but the gold was chiefly restricted to the conglomerates, 
though the pyrites of the country rock, judging from assays, contained a 
small percentage of gold. The age and origin of the conglomerates was 
uncertain, and Mr. Shaw produced no evidence of their being of marine 
origin. The connexion of the gold-bearing conglomerates and the igneous 
rocks was not settled. The richness of the reefs seemed to have no con- 
nexion with their proximity tb the igneous masses or dykes. The tilting 
and dislocating of the strata was prior to the igneous intrusions. The 
future prosperity of the Witwatersrandt gold-fields was fully established, 
and was independent of any theories which may be proposed to account 
for the origin of the gold or of the conglomerates. 

Mr. S. H. Cox (London) said he considered Mr. Shaw's paper to be a 
very interesting and important one. The paper seemed to cover such n 
lot of ground, commencing with the earliest period of geological history 
to the present time, that to abtempt to discuss it would be impossible. 
He scarcely agreed with Mr. Shaw's contention that a river could not 
deposit conglomerates such as those described. He knew of places — the 
Canterbury plains for instance, in New Zealand, about 90 miles long 
and 50 wide, shingly plains deposited by the rivers. Mr. Shaw's statement 
as to the source of the gold rather appealed to him as likely to be correct in 
some cases. He did not believe that the infiltration of sea-water had 
deposited gold, for if it had been able to deposit gold at all the 
deposition would have been world-wide, and wherever they had marine 
conglomerates they would get deposits of gold. But he thought Mr. 
Shaw had pointed out that infiltration of waters charged with gold had 
to a certain extent altered the matrix of the conglomerates, and, in 
altering it, had met with something to precipitate the<gold, and from 
that point of view he thought Mr. Shaw had certainly given them some- 
thing new. He might mention that in New South Wales there was a 
deposit known as the Junction Eeefs at Belubula, where in about 90 feet 
of strata there were 50 feet of auriferous material alternating with slates. 
The thickest of the auriferous beds being 18 feet and the thinnest 2 or 
S feet ; and these gave ^ ounce of gold to the ton in crushing ; the beds 
consisted of sand, they were not conglomeratic in any form but were 
impregnated with free-gold and interstratified with beds of slate. If one 
attempted to go into the theories of past times he took rather a different 
view from Mr. Shaw, who thought they would require an accurate know- 
ledge of the past to know the present ; for he thought they should have 
an accurate knowledge of the present to know the past. 



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180 DISCUSSION— AUEIFKR0U8 C0NGL0MERATK8 

Mr. 0. J. BiNNS (Netherseal) said Mr. Cox, in the last portion of 
his remarks, had anticipated what he was going to say ; he was sorry 
for it, but he would cap his observations by a quotation. 8ir A. Geikie 
in one of his books says ^* that the present affords a key with which to 
unlock the secrets of the past." Perhaps everybody present except Mr. 
Shaw would acknowledge that, and that if they were to abstain from 
drawing conclusions in geology until the Survey had finished, what 
might be called the pre-pre-pre-Cambrian rocks of the Western Highlands 
of Scotland, they would have to wait a long time. 

Mr. D. A. Louis (London) said that judging simply from a study 
of the characters of the conglomerate rocks, as exhibited in samples to 
which he had had access, it seemed highly probable that they should be 
of river-formation; he did not think it possible that they could have 
been formed in the sea, without including some fossils iadicative of 
such an origin. What had been said by Mr. Halse and Mr. Cox iu refer- 
ence to extensive shingly deposits formed by rivers was also evidenced 
in the vicinity of the upper reaches of the Missouri river in America. 
There, vast beds of auriferous and ferruginous gravels are found deposited 
on the bed-rock, and above them huge deposits of river sand, varying 
from 50 to 100 feet in thickness, and above that again beds carrying 
gold are sometimes encountered. These deposits are quite loose at or 
near the surface, but lower down are frequently conglomerated, but are 
in no way metamorphozed. There, however, appears to be no lack of 
existing proof of the fact that rivers are or have been capable of covering 
extensive areas with gravel-deposits. Specimens of Transvaal conglo- 
merates iu his (Mr. Louis') possession vary in character from masses of 
very coarse gravel and fine sand loosely cemented together, with each 
grain visible up to masses very closely resembling in character solid 
quartzite in which even the larger pebbles are scarcely discernible, 
indicatiog that these deposits have undergone varying degrees of meta- 
morphism. In the less metamorphozed specimens, the gold is generally 
found in the cementing or fine material surrounding the larger pebbles, 
and is associated with pyrites; and this under the microscope appears 
generally in small rounded grains and but rarely in well-defined crystals. 
Inasmuch as the reader of the paper, like others who have seen much of 
these conglomerates, admits that the pebbles sometimes contain gold and 
pyrites, thus proving the existence of these substances in the original rocks, 
and, moreover, as a deposit of coarse pebbles like those met with in these con- 
glomerates would provide most favourable conditions for the settlement 
and concentration of small grains of heavy material brought down by the 



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OF THE WITWATBRSRANDT. 181 

river, it seems feasible that these minerals might have come from the 
same rocks as the pebbles or some other ancient auriferous strata. The 
specimens examined by the speaker did not present the usual charac- 
teristics of minerals, complex, deposited from infiltering solutions, although, 
of course, any liquid or solution, auriferous or otherwise, would necessarily 
trickle through such a deposit, and the passage of a simple siliceous or 
calcareous solution would be sufficient to account for the cementation. 
The subsequent metamorphozing and tilting and other such agencies 
might account for the fine condition in which most of the gold was 
found ; and with reference to the crystalline character of the gold, some 
of the gold from the Missouri river deposit, previously alluded to, was, 
under the microscope, crystalline, although water-worn, and therefore not 
sharply crystalline. 

Mr. FiLBY (London) said the quantity of gold contained in the sea 
was estimated at a cubic mile. This was a curiously definite statement, 
and it would be interesting to know how the calculation had been made 
The paper gave evidence of Mr. Shaw's deep attention to the subject, and 
be was sure they all appreciated his ability. 

Mr. Henry Louis (Singapore) wrote that he must, in the first 
instance, draw attention to the fact that Mr. Shaw is decidedly mis- 
representing the views of mining engineers who have previously studied 
the banket beds of the Witwatersrandt, and that he was in error in stating 
that they had, up to the present, represented the gold in them as being 
"of an alluvial character and mechanically deposited.** The true facts of 
the case were exactly the opposite. The first information about the 
geological characters of this district is contained in a few brief notes 
communicated by himself (Mr. Louis) to the Mining Journal^ and pub- 
lished in that paper on November 13th, 1886*. In this communication 
he (Mr. Louis) distinctly stated that he had found the gold to be partly 
contained in the cementing-material of the banket, and that it was of a 
highly micro-crystalline character, and he further suggested that it might 
have been deposited in situ subsequently to the formation of the beds by 
the infiltration of gold in solution. So far as he knew this opinion had 
never been controverted since that time, but had, on the other hand, been 
corroborated by numerous independent writers on the subject, so that the 
theory now put forward by Mr. Shaw was in reality first promulgated by 
himself (Mr. Louis) seven years ago, or a year before these conglomerates 
were worked, according to Mr. Shaw. Of course, at the time when he 
wrote those notes, very little work had been done on the banket beds and 
that only of a most superficial nature, but the results of subsequent 

♦ Page 1325. 



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182 DISCUSSION — AURIFEROUS CONGLOMERATES 

explorations had only tended to confirm and amplify the general broad 
theories then put forward, however much it may have modified their 
details. No one, so far as he (Mr. Louis) knew, had seriously sug- 
gested the opinion which Mr. Shaw here tilts against, viz., that these 
beds were originally river-gravels. He looked upon them as marine 
beds ; this may be so, but he (Mr. Louis) preferred his original theory — 
also propounded in the above notes in the Mining Journal — to the eflFect 
that they were of lacustrine origin. He (Mr. Louis) based this view upon 
the absence of fossils, such as would be expected in marine beds, upon the 
comparatively limited area which they occupy, and upon their general 
character. Mr. W. Gibson's view that the coal-beds above them are of 
lacustrine origin, may be held to support this view to some extent. He 
(Mr. Louis) believed that the area now occupied by these beds was once an 
inland lake into which mountain streams emptied themselves — descending 
from a range consisting largely of quartzites and quartz, some of which 
were auriferous, the lake-bottom meanwhile undergoing marked oscillations 
of level. He thought it possible that the mountain-range in question may 
have occupied the site of the Drakensberg range, the strata of which are 
distinctly older than and unconf onnable under the banket-beds. Assuming 
this to have been previous to the date of the deposition of these banket-con- 
glomerates, the entire theory looks very plausible, as the known formations 
of the Drakensberg with its auriferous formations might well furnish the 
qtiartzose pebbles of the banket. Of course he (Mr. Louis) might be 
wrong in the alwve assumption as to the date of upheaval of this range ; 
if so, some other mountain-chain must have existed, the degradation of 
which furnished the pebbles. So little is known definitely of the geology 
of South Africa that all theories must be more or less tentative. The 
pebbles are so thoroughly rounded and so comparatively uniform in size 
that they must evidently have travelled long distances, and probably by 
rapid mountain streams before being deposited in this inland lake, where 
they alternated with layers of sand, the beds of gravel thinning out here 
and there and discontinuing in places to reappear again in others, oscilla- 
tions of the level of the lake-bottom accounting probably for these alterna- 
tions of gravel and sand, whilst ultimately a further rise may have produced 
the conditions which have resulted in the formation of the coal-deposits. 
The upheaval of these gravels and sands and their subsequent more or 
less complete consolidation has produced the banket beds as at present 
found with their intercalated beds of sandstone, forming a trough synclinal 
in general aspect. Mr. Gibson has, however, pointed out, and has fairly 
well established his case (although the evidence adduced by him has been 



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OF THK W1TWATER8RANDT. 183 

ignored by Mr. Shaw), that this is not a simple basin but that these strata 
show excessive faulting, reversed faulting, dislocation and folding, and 
all the other phenomena attending the disruption of strata by violent 
volcanic action. The cemen ting-material which binds the pebbles 
together is mainly siliceous ; it also carries mica and much iron pyrites, 
although the latter has been completely decomposed down to very con- 
siderable depths. This cement also contains finely-divided, highly 
crystalline gold disseminated through it. Some of the pebbles, moreover, 
are themselves auriferous. The deposition of the gold was effected after 
the formation of the beds and probably after their partial consolidation 
and uptilting. The evidence in proof of this statement is the highly 
crystalline nature of most of the gold, the very small proportion of water- 
worn gold, the fineness, the uniform distribution throughout the beds of 
conglomerate, and the absence of nuggets. Had the gold been deposited 
simultaneously with these thoroughly rounded pebbles and by the same 
agencies, it would all have been in well-rounded water-worn grains, vary- 
ing in size from flour gold to nuggets, and would have been most abundant 
in the bottom layers of the conglomerate. Instead of this we find the 
gold in very sharp-edged crystals, finely divided, and evenly disseminated 
throughout each bed of banket. He (Mr. Louis) held that the banket 
beds were percolated, after their upheaval, by subterranean waters carry- 
ing in solution gold and iron pyrites, or a substance capable of producing 
the latter. In a paper read recently before the Mineralogical Society, 
he (Mr. Louis) ventured to propound a theory to the effect that the 
solvent of gold in nature had been alkaline and not acid as generally 
supposed, and this view would accord well with the siliceous character of 
the cement binding the pebbles together. In fact the deposition of 
pyrites and gold may be looked upon as a stage of the metamorphism 
which has transformed the layers of loose gravel into the conglomerates 
of to-day. Of course the solution, which could percolate readily through 
the conglomerate-beds, would also find its way to some extent through 
the denser sandstones ; hence we should expect to find, and we do find, 
that these sandstones are slightly auriferous in the neighbourhood of the 
banket-beds. The deposition of the gold from its solution was deter- 
mined, either by the chemical action of the iron pyrites, or was caused 
by the same reducing action which produced the latter mineral. Either 
theory will account for the fact that so large a proportion of gold is free 
even at great depths, where iron pyrites forms a considerable proportion 
of the cementing-material. A similar action has no doubt produced the 
crystalline gold of the Devil's Kantoor and some parts of the Pilgrim's 



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184 DISCUSSION— AUUIFBROUB C0NGL0MBEATB8 

Rest district, which also owes its orip:iii to chemical action, and is not 
alluvial, although sometimes spoken of by that term. It is possible, 
though by no means yet proved, that this gold was formed simul- 
taneously with and by the same agencies as the gold in the banket- 
beds. He (Mr. Louis) might briefly recapitulate his ultimate views as 
to these banket beds as follows : — That the banket series of the Witwaters- 
randt forms an iri^egular, much faulted, trough of alternating sandstones 
and conglomerates which were originally of lacustrine origin, and had 
been uptilted through violent eruptive action to their present steep angles 
of dip ; that the gold contained in these deposits is partly in the pebbles 
themselves, to a very small extent is water-wora gold contemporaneously 
deposited, but it is principally crystalline gold occurring in the cementing- 
material, deposited by chemical action in the interstices between the pebbles 
of the banket, after the upheaval and partial consolidation of the latter. 

Mr. F. G. Shaw stated that he was, however, very pleased to observe 
the general acceptance of the two theories by Mr. Halse and by Mr. Cox, 
and could only hope that they would be enabled to visit South Africa, as 
he felt convinced they would then be able to concur fully in his theory. 
He (Mr. Shaw) thought that from whatever source the gold came, it would 
not be likely to be deposited evenly in all places ; where it encountered 
chemicals likely to crystallize it from solution, it would there be deposited. 
The precipitation of gold from salt water would depend on the mineral 
filling the veins, or in their vicinity, through which it percolated. Although 
the existence of gold in the conglomerates on the Gold Coast of West Africa 
was an interesting fact, this region was so distant from the Witwaters- 
randt district, and of so entirely a different geological character that a 
comparison could hardly be made, especially as Mr. Halse admitted their 
much more recent age. He (Mr. Shaw) had clearly pointed out in his paper, 
that many conglomerate formations were due to river action, and that 
nearly every alluvial gold-field had been thus created ; but the remarkable 
parallelism, uniformity of thickness, evenness of footwall, and extent of 
the Witwatersrandt beds precluded the idea of their fomlation being due 
to river action. Had Mr. Halse visited the Witwatersrandt gold-fields, he 
would undoubtedly be the first to admit that neither river action nor that 
of currents at the bottom of the ocean would satisfactorily account for the 
spreading of these conglomerates so evenly and with such a perfect footwall 
over so large an area. Mr. Halse had endeavoured to show that the matrix 
of the conglomerates was due to metamorphic and not to jDseudomorphic 
action ; but he (Mr. Shaw) jwinted out that this was not at all probable 5 
the smallest pebbles showed no sign of metamorphic action, and, as the peb- 



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OF THE WITWATBRSliANDT. 186 

bles and the matrix were of the same mineral, what altered one would affect 
the other. Mr. Binns' inability to understand the meaning of the simile 
advanced in the paper, that " a thinker to be able to understand the difficult 
phenomena of the present must know the past," could be best met by the 
following quotation from Sir Charles Lyell: — "It would be endless to 
attempt to reply to all objections urged against those who would represent 
the course of nature at its earliest periods, as resembling in all essential 
circumstances the state of things now established "• and the words of Sir A. 
Geikie's quotation, just quoted by Mr. Binns, "that the present affords a key 
with which to unlock the secrets of the past," and with the knowledge so 
obtained to explore the mysteries of the present and acquire the treasures 
now hidden. He (Mr. Shaw) stated in his paper that "these seams, the 
author expects, will assume a horizontal position at comparatively short 
distances from the tilted outcrops" which is undoubtedly proved by com- 
paring the dip of the reefs at their outcrop with the records of the dip at the 
deep-level boreholes. In stating that it was certain " that the beds never 
assumed a horizontal position," Mr. Gibson spoke without the slightest 
evidence to corroborate his assertion ; and he was entirely mistaken when 
he said, "that the southernmost reefs always possess a dip not much less 
than 15 degs. He (Mr. Shaw) had surveyed the Meyer and Lebe gold- 
mine, and found that the southernmost reefs (only 4 miles from the main 
reef) had a constant dip of 6 degs., and that the whole of the black reef 
series was equally flat even at its northern edge. It was incorrect to say 
that the section of the Ginsberg mine was misleading, as the drawing was 
an exact section of the reef as it existed. He (Mr. Shaw) did not state 
that the conglomerates were of marine origin, and considers that Mr. 
Gibson should confine himself to a criticism of such statements as he (the 
author) had advanced in his paper. What he said was that the pebbles, 
etc., brought down by rivers, were spread by the action of a receding or 
advancing sea-beach. The auriferous reefs have not been yet followed down 
to the igneous rocks, and Mr. Gibson has no right to assume that the gold in 
the reef is unconnected with trap rocks. He (Mr. Shaw), referring to the 
supposition that faults had been the means of throwing the seams of 
conglomerate towards the surface, contended that the evidence of the 
various boreholes proved that the seams were absolutely dipping at a less 
angle, instead of being tilted at a greater angle, as they would have been if 
they had been thrown up by faults, and he thought it would be pre- 
ferable for the reefs to assume a less dip than to be cut off by a fault. He 
(Mr. Shaw) was surprised at the tone of Mr. Henry Louis' remarks which 

* Principles of Geology ^ page 511. 



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186 DISCUSSION — ^AUBIFBEOUS CONGLOMERATES 

did not allow him to be right in any instance and attached theories to him 
which he had not advanced, and yet endeavoured to claim his (Mr. 
Shaw's) theories, the originality of which had not otherwise been ques- 
tioned. As to his (Mr. Shaw's) tilting against the theory of conglomerate 
beds being originally river-gravels, his paper did not even suggest that 
they had been so deposited. Mr. Louis claims to have advanced state- 
ments in a November number of the Mining Journal of 1886*, which he 
says have never been controverted, that the conglomerates of the Wit- 
watersrandt had been formed by streams depositing in a lake the detritus 
derived from surrounding mountains. On this point he is one of those 
who have advanced the usually accepted theory for the formation of all 
conglomerates, namely, that of a sedimentary or subaqueous origin. He 
(Mr. Shaw) considered this to be (in the case of these conglomerates) a too 
general term — as both these words have a wide and not a precise enough 
meaning — and he therefore advanced the theory of a retreating or advanc- 
ing sea-beach action as being more definite. As regards this theory, he 
(Mr. Shaw) was very pleased to find that Prof. A. H. Green, who had arrived 
at the same conclusion regarding the Dwyka conglomerates of the Cape 
Colony, says in his Geology and Physical Geography of Gape Colony^ 
with reference to the Dwyka conglomerates, "the notion I formed as 
to the origin of this rock was that it was a coarse shingle formed along a 
receding coast line."t This he (Mr. Shaw) considered coming from so 
high an authority as confirming the views he separately formed as to the 
formation of the Witwatersrandt conglomerates wliich, as he had stated, 
show most clearly how unsatisfactory a river or lake ac^tion theory is in 
accounting for their present appearance. His (Mr. Shaw's) statements on 
this point are not therefore inaccurate, nor do they misrepresent the views 
of mining engineers but are corroborated by his (Mr. Louis) evidence. 
No mountains exist or have existed near these conglomerate beds, and no 
lake action would account for the spreading of these conglomerate beds 
over South Africa, and for alternately laying the parallel beds of sandstones 
and conglomerates as they now exist. Crystalline gold was found and 
recognized almost from the first in these conglomerate beds by most 
mining engineers, and he (Mr. Shaw) had quoted Mr. Alford's remarks 
on the subject in his paper. He certainly was not aware that Mr. Louis 
had written on this question, as appears to be the case, in the short com- 
munication which he addressed to the Mining Journal in 1886. Mr. 
Louis' words in this letter were : — " Or whether their auriferous contents 
are not due to the deposition of gold in sitn, subsequently to the formation 
of the deposits, owing to the infiltration of gold in solution from the surface." 
* Page 1325. f Quarterly Journal Geolog. ifoc, vol. xliv., page 243. 



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OF THE WITWATBE8RANDT. 187 

Surely Mr. Tiouis does not claim this to be, at that time, a new idea, or one 
calculated to excite any surmise or comment ; he supposed if any one had 
wished to controvert such a widely accepted and well-known theory they 
would have started at least in the days of Agricola, who wrote in the 
sixteenth century regarding the minerals found in veins, which he con- 
siders had resulted from precipitation from aqueous solutions filtering 
through veins, to say nothing of having to deal with Werner who wrote in 
the year 1791, and proved the deposition theory from overhead solutions. 
Yet Mr. Ijouis in his small and by no means original communication 
claims to have advanced views which he had not since seen any reason to 
seriously modify, namely, that conglomerate beds have been formed by 
river and lake action, and that crystalline gold has been deposited from 
solutions as in the case of these conglomerate beds. Mr. Louis contro- 
verted his (Mr. Shaw's) statement, that the history of this field commenced 
with 1887 ; what he said was, that in the first year of its (crushing) history, 
this field produced 28,115 ounces of gold, and no practical mining engineer 
would have misunderstood his statement. He might remind Mr. Louis 
that the views he had advanced, and on which tlie interest of the paper 
centred, related to the origin and mode of consolidation of the conglomerate 
beds in their present form, bringing forward (firstly) a sea-beach and sea 
action to account for the spreading of the alternate layers of conglomerates 
and sandstones (a portion of his (Mr. Shaw's) paper which has not, so far, 
been upset, or seriously attacked) ; and (secondly) the pseudomorphic char- 
acter of the matrix to satisfactorily account for the comparatively simul- 
taneous crystallization of the silica, sulphides, and gold. The real difficulty 
with scientific observers has been the apparently wonderful manner in which 
these minerals are associated and combined together in a sedimentary 
deposit, and no difficulty could have been experienced in determining how 
the gold and sulphides found in a crystalline state were deposited. Mr. 
Louis had certainly not been able to disprove tlie originality of the ideas 
advanced in his (Mr. Shaw's) paper, to which he was led by the 
"mechanical deposits of the conglomerates having been altered into the 
characteristics of an ordinaiy fissure vein," as pointed out in Engine&ring 
of June ■9th, 1893.* 

The President proposed a vote of thanks to Mr. Shaw for his paper. 

Mr. W. F. HowAED (Chesterfield) had pleasure in seconding the 
President's proposal. 

Mr. Shaw acknowledged the vote. 

Mr. Spencer read the following communication on " The Support of 

Buildings" : — 

• Page 814. 



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188 THB 8UPP0BT OF BUILDINGS. 



THE SUPPORT OF BUILDINOa 



By W. spencer. 



Probably nothing connected with mining has given rise to so mnch 
litigation as the question of damage to buildings on the surface by 
underground workings and, so far as the writer knows, the subject has 
not hitherto been brought before any mining institute. In undertaking 
to read a short paper on this subject the writer thought that it would at 
least form a nucleus for additional facts, which would probably be added 
by other members, and that ultimately a large amount of valuable inform- 
ation would be recorded in the Transactions, The writer wishes at the 
outset to state that he, from the first, contemplated obtaining information 
from friends in diflFerent parts of the country ; but he did not fully realize 
the hesitation that might be felt in some cases in giving such information 
from fear of possible legal proceedings, even although the name of the 
person and the locality might be withheld. For this reason the cases 
recorded are fewer than he expected to be able to give. 

No doubt many people have been struck in travelling through different 
parts of the country with the number of buildings of diflFerent kinds 
which they have seen cracked, more or less, in localities where it was quite 
certain that no underground operations had ever been carried on. If 
similar effects are observed in districts where mineral is being worked, 
such damage is, as all are unpleasantly aware, immediately attributed to 
such workings. 

The first examples of subsidence are taken of cases occurring in 
Leicestershire, and a section of the strata in that county is given in 
Appendices B and C. The measures rise to the west, aboiit 1 in 14. 
The surface is almost level over the areas referred to. In this* district 
the coal is entirely taken away and the roads are made through the gob ; 
if any coal is left for the support of buildings, it is left as a solid block, 
and not in the form of pillars, as in other districts. 

Fig. 1, Plate VII., shows the position of a number of houses, under 
varied circumstances, none of which are damaged, with one single excep- 
tion (A). The circumstance is remarkable, seeing that some of these 



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THB SUPPORT OF BUILDINGS. 189 

honBes are in positions in which it is generally considered that injary 
is most likely to occur, i>., partly on solid coal and partly on the gob. 
The only bnilding damaged (A), and that not to a great extent, is standing 
on whole coaL It is a house of two storeys high, with a large attic 
running the length of the house. No coal had been worked within about 
90 feet of it, except on one side only. The contention of the owner was 
that it had been damaged in consequence of the underground workings, 
and a claim for compensation was made. On the contrary, the lessees of 
the colliery contended that the damage was due to the withdrawal of water 
from the foundations, which were built upon a gravel bed. This conten- 
tion was supported by the fact that a cottage on a similar foundation and 
also a large farmhouse, of similar construction to the first-named, cracked 
simultaneously with it, although the latter were too far away to be 
affected by underground workings, the last-named farmhouse being 
about two miles distant. It was thought that there was a good defence, 
but having in view " the glorious uncertainty of the law " on the one 
hand and the certainty of expense either at law or of arbitration on the 
other, the matter was settled by the lessees paying the greater part of the 
amount claimed. 

As a general rule, the greater the height and weight of a building, the 
greater the likelihood of its being damaged, although a case is recorded 
where a thick seam was worked within 60 feet of a large and high 
building without damage, while a small house near was considerably 
injured. 

As proving the effect of the withdrawal of water, a house, from under 
which the whole of a thick coal-seam had been removed, was entirely 
uninjured until, owing to underground workings many hundreds of feet 
away, the well was drained, and the house immediately cracked. 

The preceding cases. Fig. 1, and those shown in Figs. 2, 8, and 4, 
Plate VII., show a very marked contrast to each other, under circum- 
stances, so far as known, precisely similar in every respect ; in one set of 
cases no damage was done, while in the other the houses were damaged to 
a considerable extent, although at no time rendered uninhabitable. The 
buildings shown in Figs. 2, 8, and 4 are a little more than a mile 
from those shown in Fig. 1, nearly on the water-level line of the Coal- 
measures, and on a level surface. 

The following cases occurred in the county of Durham, and were 
kindly given to the writer by his friend, Mr. Thomas Douglas, of Dar- 
lington. See Figs. 6 to 16, Plate VII., and Appendix A. 



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190 THE SUPPORT OF BUILDINGS. 

In another case, fche Main Goal seam wastes lying at a depth of 150 
feet were filled with water. The Harvey seam at a depth of 420 feet 
and the Brockwell seam at 660 feet were worked out below for an area 
of about 20 acres, and no water came down. 

One of the most eminent mining engineers in the North of England 
prescribed the following conditions to secure the support of an important 
railway viaduct*: — A width of 60 feet of solid coal shall be left on every 
side, and a further width of 33 feet of pillars containing 60 per cent, of 
the whole coal. 

In another case where the coal, 3^ feet thick at a depth of 540 feet, 
was found about level — 60 feet of solid coal were left from the centre of 
the river Wear, and a further width of 132 feet was left in pillars. 

In another case all the coal was taken out beyond a distance of 96 
feet from a large house, and pillara containing 64 per cent, of the whole 
coal were left under the house without damage being done. The depth 
of the coal-seam was 480 feet, about 8^ feet thick, and lying nearly level. 

For the support of a church there were left on each side respectively 
75 feet, 90 feet, 99 feet, and 135 feet of solid coal. The depth to 
the coal-seam, 3^ feet thick, was 420 feet, the strata being nearly level. 

The manager of a colliery in Chili informed the writer that the waves 
of the sea could be heard in the workings. The coal-seam was about 
6 feet thick, and was dipping rather rapidly under the sea. 

My friend, Mr. A. L. Steavenson, of Durham, writes that — 

" He found the injury from a goaf depended : (a) on the depth, (ft) on the thick- 
ness of the seam, and (<;) veiy largely upon the nature of the surface, whether 
rocks or clay, or sand with water. Then we have to consider the support derived 
from adjoining strata if the country is level. In Durham, as you know, we have 
the wash or drift, which makes a very uncertain foundation. My house is 480 feet 
above the Brockwell coal-seam, 3 feet thick, with 40 feet of clay — this made any 
calculation doubtful, but I left as a support a width equal to half the depth, or 240 
feet, and worked round three sides of it, the result being that the building has moved 
rather than cracked, and doors have required to be cut and re-hung ; there is no 
important injury, and the well from which we get drinking water is not affected." 

" At the Skelton mines in Cleveland, at a depth of 240 feet with 20 or 30 feet 
of clay, we have taken out 10 feet of ironstone. The agent's house, 760 feet distant, 
is badly cracked, the whole hiUside seems to have slidden away (the rocks being the 
mild shales of the district). On the other hand, with the strong rocks in Durham 
and a house standing on freestone, I have taken out all the coal, 4^ feet thick, at a 
depth of 600 feet within 66 feet of a farmhouse and outbuildings, without damage 
being done (Fig. 17, Plate VII.). Twenty years ago, damages were paid for a 
house in Bishop Auckland : the coal was 4^ feet thick, lying at a depth of 720 feet, 
and the workings came within 132 feet of the house. I believe this did not really 
rlo the damage, which was caused, I think, by the water being withdrawn from a 

• The coal-seam, 3^ feet thick, at a depth of 610 feet was lying nearly level. 



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THE SUPPORT OP BUILDINGS. 191 

sandbed by the town-drains. The case went to the Assizes and the jury gave a 
verdict against the colliery owner. Water in sandstone is a frequent cause of 
damage to houses, and at law (if it can be proved that it is owing to the withdrawal 
of the water) the colliery owner is not liable." 

" I should say that at and over 500 feet in depth, with good rock only to deal 
with, there is very little fear of the removal of any seam in the county of Durham 
doing much damage." 

The writer was present at the arbitration in the case of " Bonomi 

versus Backhouse/' which has often been referred to as a test case, and 

the following is an extract from a report which appeared in the Golliery 

Ouardian of August 24th, 1861 : — 

" The house was shown to have been erected above forty years, that the colliery 
lessees had worked the coal-mines under, and contiguous to, the plaintiffs property 
in the usual manner, viz., by taking away a portion of the coal and leaving the residue 
standing as pillars to support the roof of the mine. The pillars so left were 
proved to be quite sufficient for the support of the superincumbent strata if all other 
portions of the mine had been worked in a similar manner, but in the course of 
their workings the defendants in the year 1848, worked the coal from 4^ acres, 
purchased of a Mr. Simpson, leaving pillars, and in the following year removed the 
pillars from about two acres. As soon as these pillars were removed, the roof of 
the mine which they supported fell in, and produced a goaf, called Simpson^s goaf. 
As this increased the pressure on the adjoining pillars, there was produced what 
is known amongst miners as a ^' thrust," the natural effect of which was to crush 
and knock down the pillars in the vicinity of Simpson's goaf, and as the thrust 
gradually extended the roof of the mine fell in, the strata above were disturbed, 
and the buildings on the surface, including a great part of West Auckland, were 
cracked and injured. In the year 1854, the thrust in its injurious consequences 
began to operate on the plaintiffs premises, which were distant over 380 yards 
from the point where the pillars were first removed under Simpson's land. The 
pillars supporting the roof in this portion of the mine were in turn thrown down, 
and consequently the foundations of the plaintiff were disturbed and subsided 
in such manner as in December, 1854, to cause a portion of the damage complained 
of. In 1856, the premises were still further damaged, and on May 20th in that year 
the plaintiff brought this action. The arbitration further found that the working 
of the pillars under Simpson's land was the sole cause of the damage complained 
of by the plaintiff. On these facts being found, the case was first argued before the 
Court of the Queen's Bench, and it was contended by the counsel for the defendant, 
the present Mr. Justice Hill, that the plaintiff's right to recover damages was barred 
by the Statute of Limitations, which limits the time for bringing an action, in a 
case like the present, to six years next after the cause of such action arises and not 
after. The cause of action, it was contended, was that which the arbitrator had 
found to be the sole cause of the plaintiff's damages, viz., the working of the 
pillars in 1849 which caused the thrust. The plaintiff, on the other hand, contended 
that the cause of action did not arise till damage was done, and as the effects of the 
thrust did not manifest themselves till 1854, the Statute was no bar. The judges 
of the court, including the late Lord Campbell, decided in favour of the defendant's 
contention, on the somewhat technical ground that, as one of the ordinary rights of 
proi)erty is that it shall be supported by the strata under and adjoining it, and as 
the pillars left under Simpson's land were essential for the support of the plaintiff's 
house their removal in 1849, was depriving the plaintiff of his right of support and 
therefore gave him a cause of action — six years had elapsed since such cause of 



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192 THE SUPPORT OF BUILDINGS. 

action arose, and the Statute was consequently a bar. From this decision the 
plaintiff appealed to the Court of Exchequer Chamber, which reversed the judgment 
of the Court of the Queen's Bench, and this latter decision the House of Lords has 
just now affirmed." 

In concluBion, the writer feels that with so many instances where, 
nnder apparently similar circnmstances, the results were so different, it 
seems impossible to come to any definite conclasion as to general principles, 
and that therefore each case must be decided after consideration of its 
special characteristics. In cases where the buildings are not of great 
value he is of opinion that, generally, the wisest course is to work the 
minerals and let the buildings take their chance, as, even if they are 
damaged, a slight outlay will in most cases probably make them 
practically as good as before, while the value of the minerals to be left 
would in many cases, both to lessor and lessee, far exceed that of the cost 
of repairs. In such cases the owner of a house, especially if damaged by 
the working of his own minerals, ought not to be too exacting and expect 
a new house in place of an old one, thus adding to the already heavy 
burden of the colliery lessee. 

In a recent case, in which the writer was interested, between three and 
four acres were left for the support of a farmhouse which might not have 
been damaged at all if the coal had been worked, and probably at the 
outside £50 would have paid for the injury, if any. The value to the 
lessors of the coal left was about £450. 

In any department of knowledge an accumulation of facts can scarcely 
be without value, and the writer trusts that the present paper may not prove 
an exception to the rule. 

APPENDICES. 
A.— Descbiption op Illustbations, Plate VII. 

Fig. 1. — The rise of the seams worked was at the rate of 1 in 14 to the west, 
while the surface was nearly level. The goaf in the upper (5 feet) seam, at a depth 
of 780 feet, and the goaf in the lower (6 feet) seam, at a depth of 960 feet, is shown 
by the dotted shadings. The house A, standing on unwrought coal, was damaged ; 
all the other houses were undamaged, including the house B, under which both 
seams had been entirely wrought. 

Fig. 2.— The goaf in the Upper Main seam, 6 feet thick, at a depth of 780 feet, 
and the goaf in the Roaster seam, 6^ feet thick, at a depth of 990 feet, is shown by 
the dotted shadings. A £ault, dipping south 6^ feet, is shown by a strong con- 
tinuous line. The buildings between the points A and B were considerably damaged. 

Fig. 3.— The Roaster seam, 6^ feet thick, at a depth of 990 feet, was entirely 
wrought out, and the buildings were considerably damaged. 

Fig. 4.— The goaf in the Upper Main seam, 6 feet thick, at a depth of 780 feet, 
and the goaf in the Roaster seam, 6\ feet thick, at a depth of 990 feet, is shown by 
the dotted shadings. The houses were slightly damaged. 

Fig. 6. — The Main Coal seam, 3^ feet thick, at a depth of 180 feet, was left 



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THE SUPPORT OP BUILDINGS. 



19d 



nnwToaght under the building, and was entirely surrounded by goaf. The buildings 
were not damaged. 

Fig. 6. — ^The Main Coal seam, 3 feet 10 inches thick, at a depth of 132 feet, was 
wrought in bords and walls, leaving 624 V^^ <^^^» ot the coal un wrought in the 
pillars. The buildings were undamaged. 

Fig. 7. — ^The Main Ck)al seam, 8^ feet thick, at a depth of 510 feet, was left un- 
wrought under the buildings, which were partly surrounded by goaf. A fault is 
shown by a strong continuous line. The buildings were not damaged. 

Fig. 8. — The Main Coal seam, 3 feet 2 inches thick, at a depth of 390 feet, was 
wrought in bords and walls, leaving 62J per cent, of the coal unwrought in the 
pillars. The building was undamaged. 

Fig. 9. — The Main Coal seam, 3 feet 4 inches thick, at a depth of 360 feet, was 
wrought in bords and walls, leaving 65 per cent, of the coal unwrought in the 
pillars. Some damage was caused to the buildings. 

Fig. 10. — The Main Coal seam, 3 feet 8 inches thick, at a depth of 90 feet, was 
left unwrought under the buildings, which were surrounded by goaf upon three 
sides. The building was not damaged. 

Fig. 11. — The Brockwell seam, 3 feet 8 inches thick, at a depth of 480 feet, was 
wrought in bords and walls, leaving 64 per cent, of the coal unwrought in the 
pillars. The buildings were undamaged, although surrounded by goaf on all sides. 

Fig. 12. — The Main Coal seam, 3 feet 4 inches thick, at a depth of 360 feet, was 
wrought in bords and walls, leaving 55 per cent, of the coal unwrought in the pil- 
lars. The buildings were not injured, although goaf was closely adjacent at each side. 

Fig. 18. — The Main Coal seam, 3 feet 4 inches thick, at a depth of 420 feet, was 
wrought in bords and walls, leaving 62J per cent, of the coal unwrought in the 
pillars. The buildings stand on a steep hill, inclining heavily to the south. The 
principal damage to buildings occurred at the point A. 

Fig. 14. — The Main Coal seam, 3 feet 2 inches thick, at a depth of 300 feet, was 
wrought in bords and walls, 66 per cent, of the coal being left unwrought in the 
pillars. The buildings stand on a steep hill and were not damaged, although 
. surrounded on all sides by goaf. 

Fig, 16. — The Main Coal seam, 2 feet 10 inches thick, at a depth of feet, was 
wrought in bords and walls, leaving 64 per cent, of the coal unwrought in the 
pillars. The buildings were undamaged, although surrounded with goaf ; the pillars 
were afterwards removed, and the buildings were only slightly damped. 

Fig. 16.— The Main Coal seam, 3 feet 4 inches thick, at a depth of 192 feet, dips 
eastward at 1 in 12. The workings were on the bord-and-wall system, leaving 
60 per cent, of unwrought coal in the pillars. Faults are shown by strong con- 
tinuous lines. A small area of goaf was made, and the buildings marked A, B, 
C, D, E, and F were seriously damaged. 

Fig. 17. —The seam, 4 J feet thick, at a depth of 720 feet, was wrought in bords 
and walls, and goaves formed on all sides of the buildings, which were not damaged. 



B.— Section op a Shaft Sunk thbough the New Red Mabls and Eeupeb 
Sandstones into Coal-meabukes, Refebred to in Fig. 1, Plate VII. 



No. Deioription ot StnU. 
I Red marls, with 



Thick- 
neaaof 
Strata. 
Ft. In. 



thin bands of grej 
shale and fine- 
grained sand- 
stones (skerries).. 143 



Dexyth 

from 

Surface. 

Ft. In. 



143 



No. Dosoription of Strata. 

2 Sandstone 

3 Red marl 

4 Sandstone 

6 Red marl 

6 Sandstone 



Thiok- 

Strata. 

Ft. In. 

3 

21 6 

2 3 

36 

18 



VOL. v.-iaoa* 



Deptb 
from 
Soxface. 
Ft. In. 
146 
167 6 
169 9 
205 9 
223 9 

13 



Digitized by VjOOQ IC 



194 



THE SUPPOBT OF BUILDINGS. 



Appendix 'R.— Continued, 





Thiok- 


Depth 




Thiok- 


Depth 




nevof 






nesa 


of 


from 


No DeMripUon of Stnta. 


StMto. 


Surfaoe. 


No. DeBeripttonoCStnUk 


BtnU. 


Saifaoe. 




Pt. In, 


Pt. 


In. 




Pt. In. 


Ft. In. 


7 Reel marl 


15 


238 


9 


54 Bind 





9 


617 3 


8 Sandstone 


3 


241 


9 


55 White sandstone.. 





6 


617 9 


9 Red marl 


72 


313 


9 


56 Fireclay 





6 


618 8 


10 Sandstone 


3 


316 


9 


57 COAL 


3 


4 


621 7 


11 Bind 


7 6 


324 


8 


68 Clunch or under- 








12 COAL 


1 4 


325 


7 


clay 


4 


9 


626 4 


13 Fireclay or ander- 








69 Stony bind 


9 


6 


635 10 


clay 


6 


330 


7 


60 Dark bind 


24 


6 


660 4 


14 Bind 


11 


341 


7 


61 Fireclay 





6 


660 10 


16 Grey sandstone... 


10 


351 


7 


62 COAL 


4 


6 


665 4 


16 Blue bind 


20 


371 


7 


63 Clunch 


9 





674 4 


17 COAL 


4 


376 


7 


64 Black bind 


9 


6 


683 10 


18 Bat 


9 


376 


4 


65 Stony bind 


16 


3 


699 1 


19 COAL 


1 7 


377 


11 


66 Sandstone 


4 


9 


703 10 


20 Blue bind 


42 8 


420 


7 


67 Bind, with a part- 








21 Shale 


4 


420 11 i 


ing (1 foot) of 








22 COAL 


7 


427 


11 


sandstone 


6 





709 10 


23 Hard clunch or 








68 COAL 


10 


710 8 


clay 


5 


432 


11 


69 Fireclay 





3i 


710 llj 


24 Soft bind 


26 


458 


11 


70 COAL — Uppef 








26 COAL 


6 


463 


11 


Main Seam ... 


5 





715 m 


26 Bat 


6 


464 


5 


71 Fireclay 


5 


3 


721 2j 


27 COAL 


4 6 


468 


11 


72 Bind, containing 








28 Clunch or under- 








nodules of iron- 








clay 


2 


470 


11 


stone 


11 


3 


732 5^ 


29 Bind and clunch 


28 


498 


11 


73 Fireclay with iron- 








30 Bed, with fossil 








stone 


1 


6 


733 lU 


shells 


1 


499 


11 


74 Stony bind 


4 


6 


738 5 


81 Hard sandstone... 


2 6 


502 


5 


75 Bind 


20 


6 


758 11 


82 Stony bind 


4 6 


506 11 


76 Fireclay 





6 


759 6 


33 Bind and shale ... 


9 6 


516 


5 


77 COAL 


2 





761 6 


34 COAL (soft) ... 


1 


517 


5 


78 Fireclay 


10 





771 5 


36 Fireclay 


6 


522 


5 


79 Bind 


6 





776 5, 


36 Bind 


7 6 


629 


11 


80 Sandstone 


4 


6 


780 11 
805 11 


37 Bat 


5 


630 


4 


81 Stony bind 


25 





38 COAL 


1 6 


631 


10 


82 Bind 


10 


6 


816 5 


39 Sandstone 


6 


536 10 


83 Bat 


1 





817 6 


40 Bind 


9 


545 


10 


84 COAL 


4 


6 


821 11, 


41 Fireclay 


1 3 


547 


1 


85 Fireclay 


4 





825 11 


42 COAL 


2 3 


549 


4 


86 Sandstone 


15 





840 11 


43 Bat 


2 


549 


6 


87 Shale 


4 





844 n 


44 COAL 


1 8 


551 


2 


88 Fireclay 





3 


845 2r 


45 Fireclay 


2 6 


653 


8 


89 COAL 


3 


3 


848 5: 


46 Clunch and bind, 








90 Fireclay 


9 





857 5, 


with ironstone... 


1 6 


555 


2 


91 COAL 


3 


1 


860 6i 


47 Blue bind, with 








92 Stony bind 


16 


6 


877 o; 


courses of iron- 








93 Sandstone 


9 





886 


stone 


20 


575 


2 


94 Stony bind 


3 





889 


48 White sandstone.. 


6 


580 


2 


95 Sandstone 


1 


8 


890 8 


49 COAL 


2 10 


583 





96 Bind 


19 





909 8 


60 Clunch, with courses 






97 Shale 


1 





910 8X 


of ironstone ... 


4 6 


687 


6 


98 COAL 


3 


7 


914 3| 
923 9i 


51 Bind, with courses 








99 Fireclay 


9 


6 


of ironstone ... 


1 6 


589 





100 COAL — Lower 








62 Stony bind 


8 6 


597 


6 


Main or Roaster 








53 Sandstone 


19 


616 


6 


Seam 


8 


8 


932 0} 



Digitized by VjOOQ IC 



THE BUPPOBT OF BUILDIHQS. 



196 



C— Section of a Shaft Sunk thbouoh Mabls and Kbupeb Sandstones 
INTO the Coal-mbasubeb, Rbfebbbd to in Fig. 2, Plate YII. 





TUok. 


J}0!^ 




Tblok- 


Depth 




mm 


lOf 


tmm 




IMMOf 


from 


NaDMoripfeioiiofSfenite. 


Stnta. 


SoifMe. 


No. DeBeriptkni of StnU. 


etnte. 


Sniteoe. 




Ft. 


In. 


Ft " 


En. 




Ft 


In. 


Ft In. 


1 Soil, marl, and 










66 Clunch with iron- 








akerry 


190 





190 





stone balls 


3 


4 


427 2 


2 Skerries 


I 





191 





67 COAL 


6 





432 2 


8 Marl 


4 


8 


196 


3 


68 Bat 


1 





438 2 


4 Skerry 


1 





196 


3 


69 COAL 


2 


9 


436 11 


6 Marl 


8 


9 


205 





60 Bat 





4 


486 8 


6 Skerry 


1 





206 





61 Fireclay ... 


1 





437 8 


7 Skerry 


5 





211 





62 Bind 


1 


6 


438 9 


8 Marl 


22 


9 


233 


9 


63 Rock 


8 


6 


442 3 


9 Sandstone rock ... 


1 





234 


9 


64 Bind 


3 





446 8 


10 Marl 


6 





239 


9 


66 Rock 


6 


3 


451 6 


11 Skerry 


1 





240 


9 


66 Bind 


4 


7 


456 1 


12 Marl 


6 





245 


9 


67 Rock 


1 


1 


457 2 


13 Marl and skerry... 


10 





256 


9 


68 Bind 


1 


2 


468 4 


14 Marl 





7 


266 


4 


69 Rock 


10 


469 2 


15 Skerry 


1 





257 


4 


70 Bind 


2 


9 


461 11 


16 Sandstone rock ... 


6 


2 


263 


6 


71 Rock 


2 


11 


464 10 


17 Marl 


1 


2 


264 


8 


72 COAL 


6 


8 


471 6 


18 Marl and skerry... 


5 


6 


270 


2 


73 Bind 


21 


8 


493 2 


19 Skerry 


1 





271 


2 


74 Stone bind 


1 





494 2 


20 Marl 


8 


9 


279 11 1 


75 Bind 


3 





497 2 


21 Skerry 


1 





280 


11 


76 Ironstone balls ... 





6 


497 8 


22 Marl 


4 





284 


11 


77 Bind 


3 10 


601 6 


23 Sandstone rock ... 


6 


3 


290 


2 


78 Ironstone 





2 


601 8 


24 Marl 


2 


6 


292 


8 


79 Bind 





3 


601 11 


26 Marl 


7 





299 


8 


80 Ironstone 





2 


602 1 


26 Conglomerate ... 

27 Marl 


8 


4 


308 





81 Bind 


4 


4 


606 6 


3 


6 


311 


6 


82 Ironstone 





2 


606 7 


28 Rock 


7 


7 


319 


1 


83 Bind 





6 


607 1 


29 Bind 


4 





323 


1 


84 Ironstone 





n 


607 a 


80 Bat 


1 


7 


824 


8 


85 Bind 





r 


607 11 


31 COAL 





4 


326 





86 Ironstone 





u 


608 1 


82 Clunch 


6 


6 


331 


6 


87 Bind 


10 


508 11 


33 Bind 


1 


6 


333 





88 Dark bind 


10 


609 9 


34 Clunch 


4 


1 


337 


1 


89 Bind 


2 





511 9 


36 Whinstone rock... 


25 


8 


362 


9 


90 Ironstone 





2 


511 11 


86 Bat 


1 


6 


364 


3 


91 Bind 


6 


4 


617 8 


37 Clunch 


7 


9 


372 





92 COAL 


6 





622 3 


88 COAL 





6 


372 


6 


93 Bat 


1 


4 


623 7 


89 Fireclay 


1 


6 


374 





94 COAL 


6 


2 


628 9 


40 Bat 





4 


374 


4 


95 Clunch 


8 


1 


631 10 


41 Clunch 


9 


6 


383 


10 


96 Bind 


4 


6 


536 8 


42 COAL 


1 


6 


385 


4 


97 Ironstone 





2 


536 6 


43 Fireclay 


1 


3 


386 


7 


98 Bind 


1 





537 6 


44 Sandstone rock .,. 


3 


6 


390 





99 Ironstone 





2 


537 7 


46 Ironstone 





4 


390 


4 


100 Bind 





2 


537 9 


46 Rock 


7 


1 


397 


5 


101 Ironstone 





2 


537 11 


47 Peldon 


1 





398 


5 


102 Bind 


3 





540 11 


48 Bind 


1 


9 


400 


2 


103 Ironstone 





3 


641 2 


49 Fireclay 





6 


400 


8 


104 Bind 


1 


8 


642 10 


60 Rock 


3 


6 


404 


2 


105 Ironstone 





3 


643 1 


51 Ironstone 





2 


404 


4 


106 Bind 


2 





645 1 


62 Bind 


11 





416 


4 


107 Bat 





4 


545 6 


63 Ironstone 





2 


415 


6 


108 Clunch 


2 





647 6 


64 Bind 


2 





417 


6 


109 Bind 


2 





549 6 


66 Bind 


6 


4 


428 


10 


110 Stone bind 


6 


4 


656 9 



Digitized by VjOOQ IC 



196 



THS SUFPOBT OF BUILDUTOfi. 



Appendix C-^-Continued. 





Thick. 


Depth 




neoi 


lOf 


ffoin 


No. DeaoripUoii of Stnto. 


StnU. 


SorfacD. 




Ft. 


In. 


Ft. In. 


Ill Cank 





8 


556 5 


112 Bind 


13 





669 5 


113 Dark bind 


2 


3 


571 8 


114 COAL 


1 


6 


573 2 


116 Bat 





8 


673 10 


116 Clunch 


10 


11 


584 9 


117 Rock 





9 


585 6 


118 Bind 


1 


3 


586 9 


119 Bat 





6 


587 3 


120 Bind 


4 


3 


591 6 


121 Bat 


2 


9 


594 3 


122 Bind 


3 


3 


697 6 


123 Bat 





9 


598 3 


124 COAL 


1 





599 3 


125 Bind 


8 





607 3 


126 Cank 


2 





609 3 


127 Bind 


10 


6 


619 9 


128 COAL 


5 





624 9 


129 Clunch 


1 


8 


626 5 


180 Fireclay 


3 


2 


629 7 


131 COAL 





2 


629 9 


132 Bind 


6 


6 


636 3 


133 Stone bind 


1 


9 


638 


134 Bind 


6 


3 


643 3 


136 Bind 


2 


9 


646 


136 Rock 


4 


9 


650 9 


137 Bind 


2 


3 


653 


138 Bind 


10 


6 


663 6 


139 COAL 


2 


4 


665 10 


140 Bat 





6 


666 4 


141 COAL 


10 


667 2 


142 Fireclay 


9 





676 2 


143 Sandstone rock ... 


11 





687 2 


144 Bind 


9 


2 


696 4 


145 COAL 


1 


6 


697 10 


146 Bat 





6 


698 3 


147 CANNELCOAL 


2 


2 


700 5 


148 Sloom 





5 


700 10 


149 Bind 


3 


6 


704 3 


160 Rock 


9 


4 


713 7 


161 Bind 


3 10 


717 6 


162 Stone bind 


13 


6 


730 11 


163 COAL 


6 


6 


736 5 


164 Clunch 


3 


5 


739 10 


166 Smut 


1 


7 


741 5 


166 Bind 


4 


6 


745 10 


157 Sandstone rock ... 


6 


8 


752 6 


158 Sandstone rock ... 


3 


4 


755 10 


169 Bind 


8 


4 


7r»4 2 


160 Bock 


1 


10 


766 





Thlok- 


Depth 




neai 


of 


from 


Na DeMripikmofBtnitA. 


Strata. 


Snrfaoe 




Pt. 


In. 


Ft In. 


161 Bind 


3 


7 


769 7 


162 COAL — Upper 








Main Seam ... 


5 


6 


775 1 


163 Fireclay 


1 


6 


776 7 


164 Bind 


8 


7 


785 2 


165 COAL 


1 


4 


786 6 


166 Fireclay 


1 


3 


787 9 


167 Clunch 


2 


5 


790 2 


168 Ironstone balls ... 


1 





791 2 


169 Bind 


5 


3 


796 6 


170 Bind 


8 





804 5 


171 Ironstone balls ... 


1 





805 5 


172 Bind 


7 10 


813 3 


173 Rock 





6 


813 9 


174 Bind 


3 


2 


816 11 


175 Cank 


2 





818 11 


176 Bind 


6 





824 11 


177 Kock 


3 


6 


828 6 


178 Bind 


3 





831 6 


179 Stone bind 


12 





843 5 


180 COAL 


3 


6 


846 11 


181 Bat 


3 





849 11 


182 CANNEL COAL 


2 


3 


852 2 


183 Clunch 


1 


6 


853 8 


184 Bind 


5 


6 


859 2 


185 Bind 


8 





867 2 


186 Shale 


5 





872 2 


187 COAL 


3 





875 2 


188 Fireclay 


6 





881 2 


189 Bat 


6 





887 2 


190 Clunch 


1 





888 2 


191 COAL 


3 


6 


891 8 


192 COAL and l?at... 


1 


2 


892 10 


193 Fireclay 


2 


8 


895 6 


194 Sloom 





8 


896 2 


195 Bind with iron- 








stone balls 


7 


4 


903 6 


196 Bind 


16 


4 


919 10 


197 Bind 


17 


2 


937 


198 Bind 


11 


8 


948 8 


199 Bat 





8 


949 4 


200 COAL 


3 


9 


953 1 


201 'Fireclay 


6 


10 


958 11 


202 COAL — Loner 








Main or Boaster 








Seam 


9 


2 


968 1 


203 Fireclay 


11 


8 


979 9 


204 Bat 


1 


4 


981 1 


205 Bind 


10 





991 1 


206 Rock 


6 


1 


997 2 



Digitized by VjOOQ IC 



DI8CTT8ST0K — ^THB SUPPORT OP BUILDINGS. 197 

Mr. T. A. Southern (Derby) said the paper was an interesting one 
on an important subject. A case was mentioned of a pillar of a different 
width on each side being left to support a church ; it would be well to 
have some explanation of the circumstances. In the remarks of Mr. 
Steavenson embodied in the paper certain conditions were enumerated 
upon which an injury depended. He thought to tliat should be added 
the structure and form of the surface. If the beds were at an inclination 
the gradient should be given. 

The President said general laws had been laid down in reference 
to the area of pillars required for the support of builings, out in his 
opinion, whenever practicable, it was desirable to take out the wnole of 
the ooal. Some lessors objected to this course, and he thought it was 
practically impossible to do so without causing slight damage. It was 
known that a seam of coal could not be worked without causing subsidence 
of the surface, which might affect buildings contrary to their expectations, 
sometimes causing damage where very little had been anticipated. He 
wished Mr. Spencer had recorded his views as to the area of pillars he 
would suggest should have been left under the circumstances mentioned 
in his paper, mining engineers have previously done this, but possibly he 
may have other views on the subject. He proposed a vote of thanks to 
Mr. Spencer for the trouble he had taken in preparing his paper. 

Mr. A. Sopwith (Cannock Chase) seconded the vote of thanks. He 
agreed that it was difficult to lay down rules for leaving pillars under 
buildings, but a valuable addition would be made to the Transactions if 
they could obtain from the different mining districts actual facts as to 
subsidences and what the damage was. It was possible to lower 
the surface 8 or 9 feet without damage, but a great deal depended on 
faults and other conditions, more especially with regard to the surface- 
strata and the surface-soil. He had seen buildings as much damaged 
by drainage of water as by coal-workings ; this was notably the case 
in his own district where a surface-drain was put in. The colliery- 
workings were about 200 yards from the building which sustained con- 
siderable damage, which was undoubtedly caused by the water being 
drained away. 

The vote of thanks was carried unanimously. 

Mr. W. Spencer acknowledged the compliment, and said he agreed 
with all the remarks that had been made. In reply to Mr. Southern, he 
regretted he could not give reasons for the different widths of coal left on 
different sides of the church — he gave the information as it had been 
supplied to him, and supposed it was in consequence of the dip of the 



Digitized by VjOOQ IC 



198 DISCUSSION— THE SUPPORT OF BUILDINGS. 

measures or the configaration of the sorf aoe. The dip of the measares 
in the other cases could be supplied afterwards ; it was, however, in all the 
cases, very moderate. He hoped other members would give their 
experience where the strata or the surface or both were steep, such records 
would be valuable. 



Mr. Hbndbrson exhibited and explained the instrument described in 
the following paper on a "Kapid Traverser" ; — 



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TVtuu 



^ or Biuldinas: 



Vol. VPlat£ VR, 




El^ FI6J4, 



GOAF 







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AQd1»J*/<»4*'^i4«w li#»ti'lt 



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&APID TtlAVERSl!^. 1^9 



RAPID TRAVERSER. 



Bt JAMES HENDERSON, M. Inst. C.E. 



The rapid traverser instrument is based on what is known as the 
plane-table system of surveying, and by its means enclosed and open 
traverses, both at the surface and underground, can be accomplished and 
subsequently laid down on paper with very great rapidity and accuracy. 

Unlike the plane-table, however, it is not intended that the rapid 
traverser should be used for plotting the survey in the field, a process 
involving many great objections, but this is done afterwards in the 
drawing ofiSce, with the aid of a parallel rolling-ruler and scale, and the 
result is highly satisfactory in every respect. 

The traverser (Fig. 1, Plate VIII.) may briefly be described as a circular 
metal table of about 10 inches in diameter, mounted on an ordinary tripod 
stand with the usual adjusting screws, having a brass alidade with an 
ordinary sight at each end revolving round a fixed centre-pin. The leading- 
sight a, and the back-sight h are attached to the lower frame of the alidade. 

Upon the face of the table a disc e of celluloid, Willesden waterproof 
paper, or other suitable material, is secui'ely attached by means of several 
small brass screw-nuts and bolts/, and a brass holding-down plate ^, over 
which the alidade by means of a groove can travel freely. Celluloid is to 
be preferred to any other material, as it requires no protection from the 
weather, and does not buckle under the effects of rain or water. 

This disc is divided into five concentric rings slightly scratched or 
grooved on the oelluloid, and the fiducial edge of the alidade is also thus 
divided with a small notch c at each annulus for the purpose of figuring 
or lettering the line observed and pencilled on the disc. 

The object of these concentric rings is not only to allow of separate 
sur\'eys being accomplished on one disc, but also to avoid overcrowding of 
direction-lines in any particular spot in the disc. 

The quadrant can be attached, when required by the screws d^ d. 

By means of the usual clamping-screws the table carrying the celluloid 
disc can be clamped to the stand and the alidade with the sights attached 
to the table when required. 



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200 RAPID TRAVERSER. 

The rapid traverser is worked as follows : — The iiistniment is set on 
its stand in the usual way, and levelled by means of a small portable spirit- 
level or by a level fixed to the alidade, and the alidade is sighted (by a 
back sight) on the starting point of the survey, and both the alidade and 
the table are securely fixed by their respective clamps. 

The direction of this first line of the survey is then marked with a 
finely pointed H H pencil on the selected annulus of the disc at two points 
equidistant from the centre, and duly lettered or figured within the notch 
cut in the fiducial edge of the alidade for this purpose. 

The alidade is then undamped and sighted to the forward stand or 
tripod, and clamped (three tripods being recommended for properly con- 
ducting a traverse), and the direction of the second line of the survey 
marked on the annulus as before. 

The traverser is then removed from its stand, and fixed with the 
alidade still clamped, on the forward stand, and sighted back to the tripod 
it formerly occupied, and clamped. 

This done the alidade is undamped, sighted to another forward stand ; 
it is again clamped and the direction of the third line of the survey duly 
marked and figured on the disc, and so on, for the remainder of the 
traverse, the surveyor only recording in his book the lengths of the several 
lines, with offsets as in the ordinary way. 

The magnetic meridian is taken at any convenient spot in the course 
of the traverse by means of a trough compass placed temporarily against 
the back edge of the alidade, and the line thus given pencilled on the disc, 
establishing the polarity of the whole of the survey. 

The same disc on its table can be used on any disconnected part of a 
survey by again placing the trough compass against the alidade clamped 
on the previously pencilled north line, the table being moved until the 
needle points to the north. 

The leading direction of each line is given by simply marking a half- 
arrow against the line before moving the alidade (Fig. 2), thereby showing 
the course or direction of each line. 

The fiducial edge of the alidade should always be to the surveyor's 
right hand, he facing in the direction of the next traverse-line, not only 
thereby affording greater facility for drawing and figuring the lines on the 
disc, but also preventing any chance of misplacing the guiding half -arrow 
referred to. 

In order to use the traverser on hilly ground the sights at each end of 
the alidade are marked in degrees up to 25, so that by looking over ihe 



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RAPID TRAVER8EB. 201 

top of the back sight and getting the forward object in line with one of the 
divisions the angle of declination can be at once read and reooi-ded. 

Where greater accuracy in vertical angles is required, such as in 
diagonal shafts of a mine, a quadi-ant, or properly speaking, a semicircle, 
is attached to the alidade, and the angles read to minutes, as in the 
ordinary theodolite or miner's dial. 

The method of using the traverser having now been explained, it only 
remains to describe its application in the drawing oflBce. One or more 
meridian lines having been drawn on the intended plan, the disc (Fig. 2, 
Plate VIII.) is removed from its circular table and placed, with the north 
line already marked on it in the field, in its proper position and kept theife 
by a weight or two. A heavy metal rolling parallel-ruler is then applied to 
each line of the survey in succession, as shown on the disc, and correctly 
marked ofif on the plan. In a large survey the disc can be moved to any 
one of the meridian lines as required. In short, the disc becomes a 
protractor of great accuracy, and errors in misplotting can seldom occur, 
the actual lines drawn in the field being, if carefully figured or numbered, 
represented in counterpart on the plan. 

Fig. 2, Plate VIII., is a reduced facsimile of the disc, used in the 
survey of Carnon Estate, parish of Feock, county of Cornwall ; and Fig. 8, 
shows the draft lines of the survey produced from the disc. 

For future reference the disc itself may be kept, the name and date of 
the survey being recorded thereon, or the magnetic bearings of the lines 
may be read off with facility, and the same entered in the field or survey 
book, when the celluloid disc can be cleaned with soap and water or by 
means of india-rubber and rendered quite fit for the next occasion. 

A convenient method of reading off the bearings is to place the disc in 
the centre of an ordinary cardboard protractor, which has been cut out for 
the purpose, both being pinned to the board. A central metal spill 
projects from the board, and by means of an alidade constructed so as to 
work on this spill the bearings are read off with ease and rapidity. 

The inventor of the rapid traverser has used this instrument with 
great success both underground, in mines, and in surface surveys. Its 
simplicity will be at once seen and recognized by the professional surveyor, 
who, when he knows that all his survey lines are being truthfully registered 
with the very least degree of trouble to himself, will no doubt appreciate 
its merits. 

The inventor was at first apprehensive that the wet and dirt to which 
the instrument would be exposed when used in mines would be a serious 
drawback to its application, but from experience he is able to say that 



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202 RAPID TRAVBBSER. 

oelluloid discs are not liable to injury underground. A dash of dean 
water applied at any time will eflFectually remove any dirt, without the 
slightest obliteration of the pencil marks, which can be made as readily 
and as permanently when the disc is under a film of water as when it is 
perfectly dry. 

The rapid traverser can be readily used for setting out in the field, 
lines at right angles, or at any required angle, the necessary lines on the 
disc being drawn in the office beforehand. For rapid triangulation-work 
the traverser now described can be used with great advantage. A suitable 
base-line having been measured, it only needs to set up the traverser at 
each end in succession, when the bearings of all required distant points can 
be noted on the disc, and the work subsequently plotted in the office to 
any scale. 

The instrument being very portable, requiring no skilled manipula- 
tion, no reading of angles, and no subsequent calculation, should be found 
most useful for military purposes. It could be worked with rapidity in all 
weathers, and the salient points of the country, the position of the enemy, 
etc., subsequently mapped with speed and accuracy. 

The traverser could also be used as a range-finder and with a previously 
measured base-line, traversers worked simultaneously from both ends, 
the range of even a moving object could be discovered with an accuracy 
approximate enough to be of considerable advantage. 



On the motion of the Pbebidekt a vote of thanks was accorded to 
Mr. Henderson for his paper. 



The following paper, by Mr. John Milne, "On Earth Pulsations and 
Mine Gas," was read, and a tromometer was kindly exhibited and explained 
Mr. Horace Darwin :— 



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^'"'^ Traverser 



Vol, Y.Plate VDl, 



FIG. 3 




Skeleton Map OF^T^Ay^RSE LmESpigi^i^^^ ^y GoOqIc 
As Ruled off from Adjacent Disc ^ 



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ON BABTH PULSATIONS AND MIKE GAS. 208 



ON EARTH PULSATIONS AND MINE GAS. 



By JOHN MILNE, P.R.S., F.O.S. 



1.— Inteoduction. 

In the following pages the writer chiefly refers to the resolt of his 
own observations in Japan to which is added a short critical examination 
of work carried out in Italy. 

A description of the observations made during the last twelve months 
is here given for the first time, while work undertaken by the author 
during previous years will be found in the following publications : — 

1. "Observations of Tremors, etc., in Takashima Colliery," Ja^n 

OttzettBy January 12th, 1884. 

2. "Earth Tremors," Transcictions of the Seismoloffical Society of 

Japan, 1888, vol. vii., page 1. 
8. " Earth Tremors in Central Japan," Transactions of the Seis- 
mological Society ofJapan^ 1887, vol. xi., page 1. 

4. " Earth Tremors in Central Japan," Transactions of the Sets- 

mological Society of Japan, 1888, vol. xiii.,page 7. 

5. "Earth Tremors and the Wind," Journal of the Royal Meteoroh- 

gical Society, 1888, vol. xiv., page 

6. "Reports of Committee on the Earthquake and Volcanic Pheno- 

mena of Japan," Reports of the British Association, 1881, page 

200 ; 1882, page 205 ; 1888, page 211 ; 1884, page 241 ; 

1885, page 862 ; 1886, page 418 ; 1887, page 212 ; 1888, 

page 422 ; 1889, page 295 ; 1890, page 160 ; 1891, page 

128 ; and 1892, page 98. 

In the investigations detailed in the above papers, notwithstanding 

the fact that tables were given to show that tromometric movements 

followed barometric gradients, the author attributed the occurrence of 

tremors to local or distant winds which might be the result of these 

gradients. Investigations carried on during the last year, having thrown 

a clearer light on the nature of these motions, the writer no longer 

regards them as rapidly recurring elastic vibrations, usually called earth 



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204 ON EARTH PULSATIONS AND MINE GAS. 

tremors, but rather as comparatively slow wave-like undulations of the 
soil, which, rather than being a secondary effect of barometric fluctuations 
may be an immediate consequence of such changes. 

Movements of this character may have a direct connexion with the 
escape of gas from the coals of fiery mines, they may influence the results 
arrived at in pendulum experiments, they may affect the accuracy of an 
ordinary chemical balance, and may have a relationship to many astro- 
nomical and physical investigations ; in the following pages the author 
proposes to give an outline of various researches bearing on these 
imperfectly understood phenomena. 

2.— On the Escape of Mine Gab in Relation to Earth 
Pulsations. 

To determine whether the escape of gas at a coal-mine had any 
relationship to earth movements, in 1883 the writer prepared a number 
of instruments to be used at the Takashima colliery near Nagasaki in 
Japan: the workings of which are partly beneath the bed of the Pacific 
Ocean. The movements to be looked for were the so-called earth 
tremors — which are motions altogether different in character from earth- 
quakes — and from disturbances due to the bending of superincumbent 
strata by the rising and falling of the tide. Every facility was given by 
the mine-owners for the establishment of an under-ground observatory — 
benches were cut in an old working, while a tromometer, a microphone, 
a specially-designed apparatus to measure and record yielding of the roof, 
a seismograph, and other instruments were set up. A few weeks later a 
fall occurred, and the instruments have remained buried ever since. It 
may be here remarked that the seismographs then employed, belowground 
and also on the surface, were installed not because it was supposed that 
they would give records showing any connexion with the issue of mine gas 
but more for the purpose of measuring the difference between motion 
recorded underground and that which was felt on the surface. They 
were of a very old type, designed by the writer, and practically identical 
with a seismoscope used at Mai*sdcn.* 

In consequence of the fact that Takashima is some 700 miles distant 
from Tokio, where the writer resides, but more especially in consequence 
of the death of Mr. John Stoddart, the resident engineer at the mine, 

♦ Trant» N, U, Tngt, Min. Mg, (Seismometer used at MarsdeD). voL zzxvii, 
Plate VIII. 



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ON SABTH PULSATIONS AND MINE GAB. 205 

who had undertaken chaise of the instraments, no attempt has been 
made to re-establish them.. Beference is made to these investigations 
which had bnt a bare commencement, in a paper by Mr. M. Walton 
Brown "On the Observation of Earth-shakes or Tremors, in order to 
Foretell the lasue of Sudden Outbursts of Fire-damp,"* in a report 
to the British Association on the ''Volcanic Phenomena of Japan," 
Beport for 1886, page 418, and again by M. 6. Chesneau in the Annales 
des Minesy 1888, series 8, vol xiii, page 889. 

In Mr. M. Walton Brown's paper he gives a comparison between the 
frequency of earthquakes in Great Britain and the fatal explosions of gas 
in collieries, showing that, roughly speaking, earthquakes have been more 
frequent during the winter months when gas explosions have been 
frequent. Although Mr. Brown distinctly points out that there may be 
nndulatory and vibratory motions in the earth's crust which may be 
related to the outflow of gas, in the report of the committee appointed 
to enquire into the observations of earth tremors in mining district8,t we 
only find the records of instruments which could record the occurrence of 
earthquakes. 

In France, however, at Douai, the liberation of fire-damp in connexion 
with the movements of tromometers has received careful attention, and 
the results first obtained are indicated in the Annales des Mines.X A 
fuller account of these investigations is given in the paper already 
referred to by M. Chesneau. By means of a Pieler lamp the gas in the 
returns was measured daily at 6 a.m., at which time on account of work 
ceasing at 5*80 ajn., the quantity of gas was as far as possible inde- 
pendent of the quantity of coal being extracted. 

Barometric observations were made on the surface and underground. 
The tromometric records were obtained from a 'Hromom^tre normal" 
consisting of a pendulum 1*50 metres long, the style of which was 
observed with a microscope containing a micrometric scale. 

The results obtained were briefly as follows : — 

I. Microseismic Disturbances and Fire-damp. — The curves agreed in 
direction on 81 days ; the curves disagreed in direction on 46 days ; the 
curves practically followed a horizontal line on 51 days; total, 178 days. 

II. Barometrical Fluctuations and Fire-damp, — The curves disagreed 
in direction on 76 days; the curves agreed in direction on 61 days; 
the curves practically follow a horizontal line on 54 days ; total, 180 days. 

* Trans, N, E. Irut. Min, Eng., vol. xzxiii., page 179. 
t Ihid,t vol. xxxvii., page 55. 
t Vol. is., ISSe, page 25S. 



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206 OH BABTH PULSATIONS AND MINE GAS. 

III. Mieroseismic Movements and the Appearance of Fire-damp within 
at least 24 hours. — ^When microeeisms have exceeded 1 division, the curves 
agreed 7 times and disagreed 4 times ; when microfieisms have been between 
\ and 1 division, the curves agreed 18 times and disagreed 7 times ; when 
microseisms have been 0, fire-damp has decreased 9 times and increased or 
been constant 4 times. For maxima or minima of fire-damp not included 
in the above, there were 9 cases of concordance and 2 of discordance. 

IV. Comparison of Percentage of Fire-damp and Tremors. — ^When 
fire-damp has exceeded 0*6 per cent., movements were always observed, 
that is on four occasions. When fire-damp has been below 0'5 and above 
0*25 per cent., movements have been observed thirteen times, and seven 
times they were not observed. 

V. BaromeOe Variations and Fire-damp. — When there has been a rise 
and fall of 20 millimetres or more within twenty-four hours, fire-damp 
has been observed twice and not observed once. With a variation of 
15 millimetres to 20 millimetres, it has been observed four times and not 
observed once. With a variation of 16 millimetres to 10 millimetres, it 
has been observed five times and not observed on seven occasions. 

VI. Percentage of Fire-damp and Barometric Fluctuation. — When fire- 
damp during twenty-four hours has exceeded 0*5 per cent., in three cases 
there has been agreement with barometric movements and in two cases 
disagreement. When fire-damp has been between 0*5 and 0*25 per cent., 
there have been eleven cases of agreement with barometric fluctuations. and 
thirteen cases of disagreement. 

In the discussion of results M. Chesneau points out that mieroseismic 
movements are more clearly related to the escape of gas than barometric 
movements. On some occasions this relationship between the three 
phenomena has been extremely well marked, as for example on December 
8th, 1886. 

A point in connexion with this, which although not referred to by 
M. Ohesneau, can hardly have escaped his attention, is that although the 
increase in mieroseismic movements, the increase in gas, and the 
barometric fall commenced simultaneously, the mieroseismic movements 
reached a maximum about six hours before the gas reached a maximum, 
whilst the lowest point of the barometric curve occurred even twelve 
hours later, or eighteen hours after the maxima of the tromometric move- 
ments. 

To know whether these earth movements or even their maxima 
are always somewhat in advance of the escape of fire-damp is a matter 
for future experiments and, in the writer's opinion, can only be deter- 



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ON EABTH PULSATIONS AND MINE GAS. 207 

mined by the use of iiistruinents yielding a continnous antomatic record, 
a form of which is described in this paper. The only other work with 
which the writer is acquainted bearing on the matter now under con- 
sideration is a comparison between the monthly curves of microseismic 
activity in Italy and a number of explosions of fire-damp recorded 
in Germany. The latter, which are arranged as a monthly curve, show 
a close relationship with the microseismic curve. 

8. — Observations op Earth Pulsations in Japan. 

As the results at which the writer has arrived in Japan are in several 
respects very different from those arrived at in Italy ; these will be briefly 
enumerated: the object being to compare the conditions accompanying 
the appearance of tremors with what we know respecting the escape of 
fire-damp. 

The instruments employed by the writer have been various, one of the 
first being similar to the normal tromometer of Bertelli and Rossi. As 
it often happened that the pendulums showed deflections of the vertical, 
for several years records were taken of a pair of good astronomical levels. 
At the time of a typhoon, when there are sudden changes in barometric 
pressure, it was observed that the bubbles of these instruments would 
intermittently pulsate through a range of say 1 millimetre, conveying the 
idea that the column on which they stood was being rapidly raised and 
lowered. This was the first indication obtained by the writer that the 
ground might at times be subjected to rapidly-recurring tilts. As 
indicators of gradual changes in level, notwithstanding all ordinary pre- 
cautions being taken to eliminate effects due to change of temperature, 
the writer arrived at the conclusion, reached a long time previously by 
M. d'Abbadie, that records obtained from these instruments were untrust- 
worthy. For example, it was found that with two levels placed parallel to 
each other the bubble of the one might move to the right, whilst the 
bubble of the other crept towards the left. 

Other instruments of the pendulum type were short pendulums con- 
sisting of a shot suspended by a fibre inside a vacuum tube. These 
pendulums were from 2 to 6 inches in length. Other pendulums, which 
will record elastic vibrations like those produced by a passing carriage, 
were essentially very small plates or cylinders suspended near their upper 
edges. Their movements were observed by means of a microscope or by 
watching a spot of light, reflected by a mirror which they carried, 
move backwards and forwards across a scale. For a long period earth 
movements were observed by instruments similar in type to the mirror- 



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208 



ON EABTH PULSATIONS AND MINE GAS. 



pendulimi arrangement employed by Messrs. 0. and H. Darwin in 
their well-known experiments on lunar attraction in the Cavendish 
laboratory. 

One instrument, which was used very successfully for several years 
and which gave automatic records, consisted of a heavy pendulum about 
8 feet in length, the movements of which were amplified by the motion 
of a long multiplying pointer. In general appearance this was not 
unlike the author's form of seismoscope employed at Marsden, but 
instead of the pointer multiplying the relative motion of the pendulum 
and the ground say ten times, it multiplied the motion about one hundred 
times. By a clock-work arrangement and an induction coil, sparks were 
discharged every five minutes from the end of the pointer which per- 
forated two bands of paper moving at right angles beneath. When there 
were no tremors, the records consisted of a series of holes following each 
other in a straight line about J inch apart ; but when there were tremors, 
the paper was perforated by a series of holes in all directions round the 
normal position of the tip of the pointer. From the position of the holes, 
and the breadth of paper over which they were distributed, the duration of 
" tremor " storms and their relative intensity was clearly determinable. 

Although many of the author's conclusions were based on a com- 
parison of these records with the tri-daily weather maps, he recognized 

that, on account of the natural 
period of 
chronizing 

with the period of the impulses 
called tremors and from its inertia 
which kept it swinging when earth- 
motions might have ceased, to study 
the nature of these movements more 
closely, a totally different type of in- 
strument was required. The form 
adopted is essentially an exceedingly 
light, and at the same time sensitive 
pair of conical pendulums which are 
constructed as follows : — a 6 is an 
aluminium wire supported in an hori- 
zontal position by the silk fibre a e. 
A small galvanometer-mirror is attached at a, while the needle tipped point 
of the wire rests on an agate pivot at b. By means of the levelling-screws 
de/the pendulum may be arranged to have any degree of stability. The 




the pendulum syn- 
or non-synchronizing 



Fig. 1. 



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ON KABTH PULSATIONS AND MINE GAS. 209 

adjastment given by the writer is such that a h swings with a period 
of abont five seconds. The less stability given to the system the more 
sensitive does it become to a change of level. A beam of light from a 
small kerosene lamp, having passed through a vertical slit and then a lens, 
impinges on the mirror and is reflected back upon a scale about 3 feet 
distant, where it is seen practically as a vertical line of light, and this is 
always more or less in motion. By turning a screw of the support, so that 
the bedplate is tilted to say 1 in 900, the image of light is displaced 
about 9 inches, and as the readings are to millimetres, a tilt of 1 in 
200,000 is easily noted. When the image is practically steady at any 
particular point on the scale, and the mirror is caused to swing, in a few 
minutes it returns to its normal position. A spirit lamp burning outside 
but close to the glass cover, produces no appreciable change. In a com- 
plete apparatus, two of these instruments are placed so that their planes 
of swing are at right angles and both may reflect portions of the same 
beam of light. By lifting the scale — ^which is movable — on which the 
readings are noted the vertical beam crosses a horizontal slit opening into 
a box, in which there is a photographic plate moving slowly by clock- 
work. For ordinary work the plates used moved at the rate of 12 inches 
in twenty-hours, but for a few special experiments they were caused to 
move rapidly, so that each vibration was recorded separately, and from 
the resulting diagram the period and amplitude of these could be 
measured. 

To economize space, the plate is now replaced by a drum carrying a 
photographic fihn, so arranged that the apparatus can be used in an 
ordinary room, the box containing the roll can be removed to a dark room 
in daylight, and at any moment during the day or night the movements 
being recorded can be watched and measured. From observations and 
from photographs we know that when the mirrors are caused to swing 
their period is constant, while when they are moving during a tremor 
storm their period is variable. The slowly-moving plates show that 
during a microseismic storm that maximal disturbances occur at intervals 
of from four to eight minutes. If two of these instruments are placed side 
by side to record the same component of motion, we see that they invariably 
start at the same time and in the same direction, and it is diflicult to 
escape from the conclusion that they have been simultaneously tilted. 
They do not commence gently, but suddenly, as if the column on which 
they stand, which is a massive stone structure built many years ago to 
carry an equatorial telescope, had been tilted by a wave. During a 
given storm the direction of these impulses are fairly constant. 

VOL. y,~1892-8. 14 



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210 ON EAKTH PULaATIONR AlTD MINE GAS. 

After one or two swiDgs the two may disagree in phase of motion, 
diowing that the recorded motion is compounded of the motion of the 
earth and the natural period of the pendulamB. These instroments do 
not show the effects due to elastic vibrations, such as might be caused by 
a person jumping on a pathway some yards distant from the column. 

Short pendulums with mirrors show such movements, but probably 
because they are not sufficiently sensitive to change of level they do not 
record these undulatory disturbances. From what has been said it will be 
gathered that it is the writer's opinion that the motions under considera- 
tion are not elastic vibrations, which might be implied by the word 
*^ tremor,^' nor are they microseismic. On the contrary, they are pulsatory 
motions which are irregular in period, they cause tilting, and in their 
general character may resemble the swell of the ocean. They succeed 
each other at intervals of from one to two seconds, and their maximum 
slopes recorded have reached about 1 in 40,000. We must, however, 
remember that because the mirror, light as it is, in all probability over- 
swings its mark, the slope may be less than that now stated. Ordinary 
tremors may indicate dopes of 1 in 200,000.* 

Italian writers who, as far as the writer is aware, have not attempted 
to define the character of these movements, usually divide them into baro- 
seismic or those due to barometrical influences relieving internal forces, 
which occur with barometric depression, and volcano-seismic, which are 
directly due to eSoiia at volcanic centres and which agree with periods of 
high pressure. Even if these movements are seismic, from their magnitude, 
they should rather be called megaseismic than microseismic. But as it 
is the writer's opinion that their origin may be traced to fluctuation 
in barometric pressure over considerable areas of an elastic crust, even 
the term seismic might be dismissed. For want of a better term, the 
writer calls them earth pulsations. 

4. Distribution of Earth Pulsations in Space and Time. 

In the writer's publications relating to earth pulsations, prior to the 
use of instruments which have given an insight into the character of these 
movements, their existence was shown to be in the majority of cases 
coincident with the occurrence of a local or distant wind ; that is to say, 
even if it was calm at the observing station and pulsations were recorded, 

* As the instnunents used by the writer are but poorly oonstructed, and there- 
fore not capable of accurate calibration, these measurements of slope must for the 
present only be regarded as rough approximations. 



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ON EARTH PULSATIONS AND MINB GAS. 211 

it would be found that within 200 or 300 mQes a heavy gale was blowing. 
The suggestion was then made that these movements were vibratory in 
character and had their origin in gusts of wind acting against mountain- 
ranges, and on the surface of the country over which they passed, and 
were then transmitted through the surface of the earth to distant localities 
which it might often happen that the wind itself never reached. It was 
also shown that tremors occurred almost always whenever the point of 
observation was crossed by a steep barometric gradient, and although the 
Italian observations had not been examined either in connexion with 
distant winds or barometrical gradients, what was true for Japan appeared 
to be equally true for the Italian Peninsula. 

In the following smnmary respecting the distribution of earth pulsations 
with regard to space and time, a few of the writer's observations during 
the past eight years will again be taken, but instead of considering the 
records as effects due to vibratory motions of an elastic medium, they will 
be regarded as pulsatory wave-like motions in the earth's crust, and the 
reasons for thus regarding them have been already stated. 

1. Tromometric disturbances throughout a large area (in Italy at 
least) when plotted in curves to show monthly distribution apparently 
agree in the time of their maxima and minima. 

2. The greater frequency occurs during the winter months. This is 
true for Japan and Italy, and it is at this season that we have the greater 
frequency of earthquakes, and speaking generally for Germany and 
England the greater number of colliery explosions. From an analysis of 
the investigations described by M. Ohesneau, the writer would say that 
for the particular collieries where the percentage of gas in the returns 
was measured from June to the end of October, the gas seldom reached 
1 per cent., whilst in November, December, February, and March it has 
usually been above 1 per cent. For the other months, January, April, 
and May, no returns are given. The data, such as exist, are sufficient to 
show that at this particular mine the escape of gas followed the winter 
rule. Whether this is a general rule it is not easy to determine. 
Another phenomenon following the winter rule suggested to the writer by 
his late colleague, Dr. 0. G. Knott, is that during the winter months 
many areas in the northern and southern hemispheres are crossed by 
steeper barometric gradients than in summer. For Central Japan at least 
this is very marked. For example, reckoning the gradients in millimetres 
per 2 d^s. of latitude or 120 geographical miles, the following gradients 
are found across Central Japan: — 



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212 ON EARTH PULSATIONS AND MINE GAS. 



January, 6 


.. April,! to 4.. 


July, 


... October, 2 


February, 5*6 . 


.. May, ... 


Au^nist, 


.. November, 8 


March, 5 . 


.. June, 


September, 


... December, 8 



The above gradients are calculated from weather maps showing the 
monthly means in 1885. Prom Berghau's Physikalisclcer AtlaSy as 
measured between London and Faroe for July, there was a gradient of 
0*9 millimetre, whilst for December it was 2*0 millimetres. For the Bame 
times the east-and-west gradients across France and Germany were 
respectively 0*6 millimetre and 2*0 millimetres, and generally it is evident 
from the manner in which isobars are crowded together, especially in the 
northern hemisphere in winter, and opened out in summer, that baro- 
metrical stresses acting on the surface of the earth are much greater in 
the former than in the latter season. 

8. The stronger the wind the more likely are we to observe pulsations. 
Inasmuch as a strong wind follows a steep gradient, this is little more 
than a corollary following the remarks respecting gradients. 

4. If a strong wind occurs and there are no tremors, it has usually 
been local, of short duration, or blowing in from the ocean. 

5. When there was little or no wind in Tokio and yet movements 
have been observed, it was found that there had been a strong wind in 
other parts of Japan — that is to say there has been a steep barometric 
gradient. Often a tremor-instrument announces a wind from the 
south and south-west many hours before its arrival. With no wind and 
no tremors, in 651 cases the writer observed that there was a general 
calm throughout Japan. 

6. From 75 to 80 per cent, of the tromometric storms have accom- 
panied local or distant winds, and these winds may be assumed to be due 
to steepness in barometric gradient. 

7. The only connexion between earthquakes and tromometric motions 
observed in Central Japan is that they are both more frequent during the 
winter season. 

6. Tromometric Movements in relation to Barometric 
Conditions. 

The following tables refer to observations made by the author between 
January I6th, 1885, and May, 1886. 

I. The following table gives the number of times when pulsations 
were observed when the barometer stood above its monthly mean, and 
when it was below that mean. 



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ON BABTH PULSATIONS AND MINE GAS. 



213 





High Buomator. 


Low Barometer. 




1885. 


PalutionB. 


No 
Polntions. 


PulsaUonB. 


No 
PulaatiODs. 


Total 
PoIsalioDS. 


January (from 16th)... 


6 


6 


8 





14 


February 


6 


6 


7 


9 


13 


March 


6 


... 10 


.. 11 


4 


17 


April 


4 


... 11 


6 


9 


10 


May 


4 


... 13 


6 


9 


9 


June 


4 


9 





... 17 


•4 


July 


1 


... 16 


3 


... 11 


4 


August 


2 


... 13 


4 


... 12 


6 


September 


3 


... 13 


6 


8 


9 


October 


5 


... 12 


5 


9 


10 


November 


3 


... 12 


8 


7 


11 


December 





— 








— 


1886. 












January (from 20th).. 


1 


2 


4 


2 


5 


February 


3 


... 10 


... 13 


1 


16 


March 


6 


8 


8 


3 


14 


April 


. 13 


2 


... 13 


2 


26 


May 


5 


8 


4 


1 


9 



Totals 



72 



150 



105 



104 



177 



II. Occurrence of tromometric movements in relation to barometric 
gradient. The gradients are indicated in millimetres per 120 geogra- 
phical miles, this being a convenient distance to measure on the weather 
maps. 



Qradlent. 


PolsaUoDS. 


No Pulsations. 


Peroenta«o of times 

when Pulsations 

were obaenred. 





2 


8 


20 


1 


28 


21 


67 


2 


42 


62 


44 


3 


40 


40 


60 


4 


22 


3 


88 


5 


20 


8 


71 


6 


5 





100 


7 


3 





100 


9 


1 





100 



These records embrace a period between January 20th and the end of 
May, 1886. 

From Table I. we see that tromometric movements have been 
most frequent during the winter months, and although it has often 
happened that with a low barometer there were no pulsations, yet pulsa- 
tions are more frequent with a low than with a high barometer. From 
Table II. we see that with a very high gradient pulsations always 
occur, and generally they are proportionately more frequent as the gradient 
rises. 

* The barometer ofteD very low, but no pulsations. 



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214 OK EABTH PULSATION» AND MINE GAS. 

To this may be added the observation, that, for all intensities of wind 
(the scale being from to 6 — 6 being a hurricane) the average gradient 
was steeper when pulsations occurred than when they were absent. 
Further, it may be added, that for low gradients when pulsations 
occurred, the movements were always very small, and it often happened 
that the low gradient was immediately preceded or followed by a high 
gradient. On the other hand, for high gradients the pulsations were 
always more violent. 

Although pulsations appear to be closely related to the wind, that 
they are more closely related to the gradient will be seen by comparing 
the following table with the Table IL, both tables referring to the 
same group of observations. 



Wind, 


Polmtioiu. 


Ko PolBaUoDfl. 


PeroentaceofUmea 

PoImUodb 

won obserrcd. 





10 


16 


38 


1 


53 


47 


53 


2 


64 


49 


53-4 


3 


37 


16 


70 


4 


12 


1 


92 



As confirming the results here given, reference may be made to the 
observations extending over longer periods of time, published by the 
author in vol. ix of the Transactions of the Seismological Society^ and 
especial attention is drawn to a table which shows that tremors are at a 
maximum in the Italian Peninsula when the barometric gradient is steep, 
no matter whether the barometer be high or whether it be low. 

Another investigation connecting tromometric disturbances with 
barometrical fluctuations, has revealed the fact that whenever there is a 
barometrical change of or more than 6 millimetres in 8 hours (which 
usually occurs with a falling barometer), pulsations are pronounced — 
earth pulsations may therefore be connected with the rate at which 
pressure changes. 

When seeking a connexion between the wind, barometric gradients 
and ground movements, an observation that escaped the writer's attention 
until the present year is the fact that the velocity of the wind is often far 
from being proportional to the gradient. For example, with a gradient from 
S.E. to N.W. of 5*45 millimetres in Tokio and Central Japan, generally 
the wind may be indicated as 0, 1 or 2 (velocities of zero to 3'5 metres 
per second), while with a N.W. to S.E. gradient of 8 millimetres, there 
may be wind in Tokio and in Central Japan of 8 (velocities from 
6 to 10 metres per second). Similar observations have been made in 
other countries, but the writer is not aware that the differences observed 
are so pronounced. 



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ON EARTH PULSATIONS AND MINE GAS. 216 

Although many years have been spent in investigating earth pulsa- 
tions, much has yet to be done before we shall be able to formulate all the 
laws connected with these phenomena. Their occurrence is apparently 
more closely connected with the steepness of the barometric gradient 
than with any other phenomenon ; but just as atmospheric disturbances 
depend upon the forms of isobars, the direction of their advance, the 
steepness of the gradient and the like, so may the varying disturbances of 
the earth's crust be explained by a similar complexity of causes. 

6. Theoretical Aspect op the Question. 

Because the differences in barometrical pressure are long-continued 
and are greater in winter than in summer, and also on account of the 
greater frequency of marked fluctuations in these stresses in the former 
rather than in the latter season, it does not seem unreasonable to determine 
whether variation in barometric pressure is not sufficient to account for 
the frequency of tromometric movement and escapes of mine gas, which, 
from the little information the author has been able to collect, appear to 
have their maxima at the same period. 

Fortunately this question has already been partially answered by 
Prof. George Darwin, F.R.8., in his report to the British Association on 
the Measurements of the Lunar Disturbance of Gravity. One phenomenon 
affecting the measurements of this quantity is distortion of the earth's 
surface due to barometrical loads. Assuming a modulus of rigidity for 
the earth's surface at 3 x 10® (in grammes weight per square centimetre) 
and a maximum barometric grade of 6 centimetres or nearly two inches in 
1 ,600 miles, Prof. Darwin finds that the ground would be 9 centimetres or 
about 8^ inches higher under the barometric depression than under the 
elevation. 

As the modulus of rigidity of the earth's surface is in all probability 
less than that of glass (or 3 x 10®) it is likely that the value 9 centi- 
metres or 3i inches is very much too small. Further, because the wave 
is long, even if the deflection amounted to double this amount, as Prof. 
Darwin suggests, its effects would be equally great in the deepest mines. 
This result certainly accords with the results of observations, which show 
that pulsatory movements are quite as clearly marked deep underground 
as they are upon the surface. As to whether this general bending of 
strata is likely to cause an outflow of gas is another consideration. 

The complete solution of the problem is an extension of Prof. 
Darwin's work. Instead of determining the effects of a statical load, we 
wish to know the effects of a barometrical load which is moving, first 
with a velocity equal to that of the progression of a given isobar, and 



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216 ON EARTH PULSATIONS AND MINE QAS. 

secondly with an intermittent progression corresponding for example to 
the intervals between the gusts of wind in a gale. 

After looking at a number of maps showing the tracks of barometrical 
depressions in England and Europe, it appears that an average rate at 
which a depression travels is about 20 geographical miles per hour, or say 
84 feet per second. Although the rate is high, it is probable that a 
uniform surface with the rigidity of glass would quickly adjust itself to 
the load as it passed across the surface. If however the load is irregularly 
applied upon the surface, and the surface, owing to the varying character 
of its strata, is not uniformly elastic, it does not seem unlikely that the 
surface should be broken up into a series of irregular waves. It seems 
however unlikely that the ordinary rise and fall of the tide could do 
more than produce a general bending. 

7. The Escape of Fiee-damp in Relation to Babombtbical 

Pbessube. 

The following few extracts epitomized from the writings of M, 
Chesneau and the Report of the Austrian Fire-damp Commission, the 
writer assumes to be fairly representative of the experiences of those who 
have investigated the relationship between the escape of fire-damp and 
fluctuations in barometric pressure. 

M. Chesneau, in the paper already referred to, gives an interesting 
summary of observations which have been made on the relationship 
between the escape of fire-damp and atmospheric pressure. 

M. Le Chatelier, after a critical examination of the investigations 
made by Galloway between 1868 and 1873, arrives at the conclusions that 
it is doubtful if variations in atmospheric pressure have any relationship 
with the escape of gas. 

Mr. Schondorf, who made observations in the Saar Basin, concluded 
that barometric fluctuations directly affected the escape of gas from the 
goaf. M. Nasu, by carefully examining the gas issuing from a particular 
bed, found that it increased with a barometric fall; but, as pointed out by 
M. Chesneau, it is likely the increase may have been solely due to a greater 
escape from the area enclosed by stoppings rather, than an increased rate 
of distillation from the coal. 

The experiments of M. Hilt led to the conclusion that gas increased 
with a barometric fall, and mce versd^ but the examination of M. Hilt's 
results by Messrs. Mallard and Le Chatelier showed that great barometric 
falls only correspond with the appearance of small quantities of gas, whilst 
in regions cut off from goaf the correspondence was barely evident. 



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ON EARTH PULSATIONS AND MINE GAS. 217 

In the case of one considerable fall, at one mine the gas decreased 
while at another it increased. 

The conclusions arrived at by Mr. Eohler at certain mines in Silesia 
were as follows : — 

1. The quantity of gas diminishes with a iise of the barometer, and 

vice versd, 

2. The quantity increases proportionately to the rate at which the 

barometer falls, and rnce versd. 
8. The quantity of gas disengaged is not absolutely dependent on 

the height of the barometer. 
4. If the barometer rises rapidly and after that very gently, or 
remains steady at its maximum, a small increase of gas takes 
place ; inversely if it falls rapidly, and then gently rises or 
remains long at a minimum, a diminution in the quantity of 
gas commences. 
The quantity of gas was determined by chemical analysis. 
The closest agreements between barometric fluctuations and the dis- 
engagement of gas occur at the mines where the old workings cover an 
extensive area. Mr. K5hler also made experiments by hermetically sealing 
the downcast and producing a depression by the revolutions of a fan, with 
the result that the quantity of gas was considerably increased, even when 
there wafi no communication with the goaf. 

From the researches of the Austrian Fire-damp Commission, in five 
districts not containing old workings, practically no connexion was 
observed between the liberation of fire-damp and fluctuations in barometric 
pressure. It was, moreover, shown by experiment that the gas was con- 
tained in the coal under considerable pressure (in one case as high as 9*2 
atmospheres), from which it might be inferred that slight barometric 
changes would produce no sensible effect upon the escape of gas. It 
was also observed that the volumes of gas collected from boreholes did 
not vary with atmospheric pressure. 

The gas coming from old workings closely followed the barometric 
curve.* 

Conclusions. 

The facts of chief importance now before us are as follows : — ^As a result 
of observations made with exceedingly light tromometers and delicate 
levels, and other instruments, like delicate balances, the writer concludes 
that areas of the earth's surface are at times thrown into a series of flat 

* Trans. Fed, Inst., vol. iii., page 534. 



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218 Oy EARTH PULSATIONS AND MINE GAS. 

wave-like undulations. These disfcurbances are frequent in the winter 
months. They may occur either with a high or low barometer, but 
they nearly always accompany a steep gradient. Theoretical considera- 
tions indicate that such disturbances might arise from fluctuations in 
barometric pressure exerted over extended areas. From the little informa- 
tion at the author's command it appears likely that fire-damp escapes 
in greatest quantity when earth pulsations are most frequent, but as 
to whether the compression and extension by repeated bendings which 
are slight in depth but great in length, influence the escape of gas is a 
matter for speculation. From the last quotations, which may be ampli- 
fied by appealing to the results obtained by other investigators we may 
conclude : — 

1. That a local barometric fall is directly connected with the 

escape of gas from old workings and goaf. 

2. That local barometric changes have at least in the majority of 

cases but little, if any, appreciable effect on the escape of gas 
from coal. 

One means of testing the writer's views would be to determine whether 
the escape of gas from the coal at any mine shows a relationship to the 
barometric- gradient existing at the time of observation across the district 
in which the mine is situated. 

Assuming the author's investigations should meet with confirmation, 
it would seem that our coal-mining districts should have the same 
facilities for quickly determining barometric gradients, the varying forms 
of isobars and the like, as are afforded to the seaports. Each mine should 
be able to ascertain at any moment the gradient and its direction, 
measured over a length of, say 200 miles ; and in addition, a tromometer 
which will at any time show not only the range of the resulting pulsatory 
motions, but their direction should be consulted. 

Neither earthquake instruments nor ordinary tromometers which 
continue swinging by their own inertia, and may show maxima of motion 
when the actuating cause is at a minimum, and which naturally tend to 
change their planes of oscillation, should be employed. The instrument 
recommended, although by no means perfect, is the one described in this 
paper, which, having extremely little inertia, roughly measures the tilting 
and also indicates the direction from which the displacement approaches. 



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DISCUSSION—ON EABTH PULSATIONS AND MINE GAS. 219 

Mr. C. Davison (Binningham) wrote, it appeared to him that there 
were many facilities in England for carrying out the observations suggested 
by Prof. Milne, and it was extremely desirable that advantage should be 
taken of them. The instrument described by Prof. Milne was simple and 
could probably be made at small cost, but his remark that, after one or 
two swings, two of these instruments may disagree in phase, showed that 
their indications, though useful, could not be entirely trusted. Possibly, 
however, this defect might be remedied to a considerable extent by 
inmiersing the instrument in paraffin oil. He (Mr. Davison) believed 
that the instrument most suited for the purpose would be either Dr. E. 
von Rebeur-Paschwitz's horizontal pendulum or Mr. Darwin's new form 
of pendulum with double-suspension mirror. The latter will be described 
in the report of the British Association's Earth Tremor Committee for 
the present year. Dr. von Rebeur-Paschwitz has given an account of his 
horizontal pendulum and of the results which have so iar been obtained 
with it in his valuable memoir, "Das Horizontalpendel, etc."* Both 
instruments are of great delicacy, and their employment in mines, where 
creeping has ceased to be perceptible, could hardly fail to lead to results 
of great value, and possibly of important pi-actical application. 

The Presidbnt proposed and Mr. Spencer seconded a vote of thanks 
to the author of the paper and to Mr. Horace Darwin for his kindness in 
attending and explaining the use of the tromometer. 

The vote was accorded unanimously. 



The President said they must pass a hearty vote of thanks to the 
Institution of Civil Engineers for the use of their rooms, and to the 
owners and managers of the works which had been so kindly thrown open 
to their inspection during the meeting. 

Mr. A. SoPWiTH (Cannock Chase) seconded the proposal, which was 
heartily approved. 

Mr. Henry Lawrence (Durham) proposed a cordial vote of thanks 
to the President for his services in the chair. 

Mr, F. 6. Shaw (London) seconded the motion, which was cordially 
adopted. 

• Nova Acta der Ktl. I^eop, Carol. Deutsehen Ahademie der Naturfortehor, 

vol. Ix., No. 1. 



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220 THE WESTMINSTER ELECTRIC SUPPLY CORPORATION, 

The President said he was obliged to the members for their vote, 
but they had heard so much of him during the last two days that he would 
not say more now than that this had been, so far as he oould see, a most 
successful meeting. 

The meeting then terminated. 



The following notes record some of the features of interest seen by 
visitors to works, which were, by kind permission of the owners, open for 
inspection during the course of the London Meeting on June 2nd and 8rd, 
1893 ;— 

THE WESTMINSTER ELECTRIC SUPPLY CORPORATION. 

The area served by the Westminster Electric Supply Corporation, 

Limited, extends from the Thames to Oxford Street, and from Whitehall 

westward across Belgrave Square. The district is served from three 

stations, marked by small black blocks on the annexed map. These are 

situated respectively in Millbank Street, on the river and just south of the 

Houses of Parliament; in Eccleston Place, near Buckingham Palace 

Road ; and in Da vies Street, near Oxford Street, and midway between 

Regent Street and Park Lane. The capacities of these stations, stated in 

8 candle-power lamps, are as follows : — 

Davies Street 84,000 

Eccleston Place 42,000 

Millbank Street 60,000 



Total 186,000 

The number of lamps connected to each station may now (May, 1893) 
be stated approximately as : — 

Davies Street ... 55,600 

Eccleston Place 32,100 

Millbank Street 21,000 

Although the area is served from three centres, all the stations are 
connected to the general network of mains, and in slack times two stations 
may be shut down, leaving one to undertake the load. 

The system adopted is low-tension direct-current distribution, with a 
third wire connected to a battery, which not only aids the regulation, but 
also supplies current in the night when the engines are stopped. The 
dynamos are wound to give a cun*eut of 220 volts pressure, and their 
terminals are connected across the outer mains. The current is distributed 
to the various parts of the network by means of feeder mains at a pressure 
of 102 volts, and of 100 to 101 volts in the distributing mains. 



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THE WBSTMIKSTBR BLECTEIO SUPPLY CORPORATION. 



221 



The street mains are laid wherever possible upon the Kennedy system. 
The culverts are formed of concrete. The carriers are of earthenware, and 
are let into the concrete, which is covered with bitumen to prevent damp. 
Copper strips are laid upon the supports, which are placed at intervals of 
6 feet, so that no straining devices are needed as with the Crompton 
system. "Where it is impossible to use culverts, Callender-Webber conduits, 
or cast-iron casings, are used, and where this is impossible iron-pipes are 
employed, into which the cables are drawn. 




The price charged for the current was originally 8d. per Board of 
Trade unit. This was reduced to 7d. in 1892, and since March, 1893, 
has been further reduced to 6d., with a rebate to large consumers. 



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222 THE WESTMIN8TBB BLBCrTRIO SUPPLY OOEPOBATION. 

Prof. A. B. W. Kennedy, M. Inst. O.B., is the engineer-in-chief to 
the Corporation, and has designed the three stations, to which Mr. 0. 
Stanley Peadi, John Street, Adelphi, has acted as architect. 

Davies Stbket Station. 

The bnilding in Davies Street is of a handsome appearance, and is 
several storeys in height, the ground floor being utilized for shops and the 
flats for residential chambers. Between these blocks of buildings is an 
open space in which is situated the engine-room, covered with a light 
roof. The chimney passes up the central space, independent of the walls 
of the building. 

Oreat care was given to the construction of the engine-block which 
consists of concrete, 10 feet thick, isolated by 18 inches space from 
surrounding walls, and carries the entire range of engines and dynamos. 
Its lower surface is arched, and the rounded spaces are filled with sand to 
prevent the block from rocking. The chimney-base is at a lower level 
than the engine-base. 

The ten dynamos are each driven directly by a Willans compound 
engine. Two are Crompton dynamos, each giving 450 amperes- at 120 
volts pressure, and driven by G Gr Willans engines. These machines are 
two-poled, and are used for balancing. When the loads on the two sides 
of the system are unequal, and there is a considerable current on the 
central or third wire, one of these machines is employed to redress the 
difference, and produce a balance. The two next dynamos are four-pole 
machines, built by the Electric Construction Corporation, each giving .800 
ampires at 220 volts pressure. They are driven by H H Willans engines, 
having low-pressure cylinders 17 inches in diameter by 12 inches stroke, 
and running at the slow speed of 175 revolutions per minute. The four 
adjacent dynamos are two-pole machines, also built by the Electric Con- 
struction Corporation ; they are driven by II Willans engines, running at 
850 revolutions per minute, the output being 500 amperes at 220 volts 
pressure. The two remaining dynamos are of the Crompton four-pole 
type, and of 112 kilo-watt capacity. A large steam dynamo, by Messrs. 
Latimer, Clark, & Muirhead, giving 1,000 amperes at 220 volts will be 
added during the summer. 

The boilers are of a modified marine type, four being constructed by 
Messrs. Davey, Paxman, & Co., of Colchester, and two by Messrs. Eraser 
& Eraser, of Bow. Each boiler is 8 feet in diameter by 12 feet long, and 
contains two furnaces 2 feet 8 inches in diameter, crossed by two Gkdloway 
tubes. There is a dry combustion-chamber at the back of the boiler, into 



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THE WB8TMIN8TEB BLECTBIO SUPPLY CORPOEATION. 228 

which the gases are delivered previously to their passing through the 92 
8 inches tnbes^ which lead them back to the smoke-box over the furnace 
fronts. The gases then flow into capacious side and bottom-flues, and 
thence into the main flue, which runs underground between the two rows 
of boilers. This flue delivers into the chimney, which is 180 feet in height 
from the firing level. There are six boilers already installed, a seventh 
will be put in during the summer, and space is left for three others. 
One special advantage of this type of steam generator arises from its 
shortness, which enables it to be got into and out of cramped premises 
with comparative ease, and it can be used in circumstances where the 
Lancashire boiler would be quite inadmissible. 

The boilers are fed by two Peam quadruple-acting pumps with 8} inches 
plungers, and one with 4^ inches plungers. The feed is pumped through 
two Berryman heat^ situated at the end of the row of engines, where the 
temperature is raised to 200 degs. Fahr. ; and the exhaust steam can be 
directed entirely up the chimney, or wholly through the feed-heaters, or in 
any proportion desirable, by one large sluice-valve situate in the mean 
exhaust pipe. The exhaust pipe is led up the centre of the chimney to 
within a few feet of the top. To guard against the machines being 
damaged by lightning passing down this pipe, there are two lightning con- 
ductors, and the pipe itself is most carefully connected to earth, so that a 
flash may pass off innocuously, and not damage the coils of the dynamos. 
The 8 inches steel steam-pipes are in duplicate in the boiler-house, and the 
engine-room steam-pipes will soon be complete in a ring. By this arrange- 
ment leaky joints can be dealt with at any time, without stopping the 
engines. The coal enters by the roadway, and there is considerable storage- 
room for it in cellars under the pavement and adjoining the boDer-house. 
A small tramway is provided for its distribution. 

There is a voltmeter between each pair of engines to regulate the pres- 
sure, connected to a distant feeder. Supposing one engine to be running 
and the demand to be increasing, the regulator is opened wider and wider to 
keep up the pressure until the full power of the engine is reached. Then 
the second engine is started, and the same plan followed until it is fully 
loaded. The third engine is then started, and so on. When the load is 
decreasing, the engines are slowed down, and stopped one by one in the 
inverse order. From the distant end of each pair of feeders, wires are led 
back to voltmeters, to show the pressure in various parts of the network. 

Automatic cut-outs are used to prevent the battery discharging back 
through a dynamo, in case the engine should stop. By means of magnetism 
induced by the current flowing through a coil, a heavy handle is held up ; 



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224 THB WESTMINSTEB BLBCTBIC SUPPLY CORPORATION. 

if the cnrrent dies away the handle is released and falls, and in so doing 
operates a switch to break the drcait. 

It is barely two years since the station was first started, and already it is 
so sncoessful that 10,000 lamps have been fed from it at one time. 

Mr. LI. Foster, Assoc. M. Inst. C.E., is the resident engineer. 

EccLBSTON Place Station. 

The site of the station at Eccleston Place is the largest of the three 
generating-centres ; it is situated near Victoria Station, and a little 
north of Buckingham Palace Road. The Underground Railway passes 
the block, and the necessity of building part of the station over the 
tunnel added considerably to the difficulties of both architect and engineer. 
The store-rooms are all placed upon the ground-floor and basement at 
this end of the building, and the upper floors are occupied by the ofiices of 
the company, and the rooms of the resident engineer Mr. C. 0. Grimshaw. 

The total area which belongs to the company measures approximately 
224 feet long by 101 feet wide, and of this rather more than half is now 
covered by buildings. Two main entrances are provided, so that coal-carts 
will enter at one door, pass on to a weighbridge, the coal wUl then be 
discharged into the stores in the basement, and the empty carts will pass 
out by the second door. Tram-lines are laid in all the passages, so that 
the coal is easily brought to the boiler-house. It is possible to store at 
least 800 tons at one time. 

The boiler-house is below the ground level, and at present four boilers 
are installed ; three are of the marine type, built by Messrs. Davey, Pax- 
man, & Co., of Colchester, two are 12 feet long by 8 feet in diameter, 
the third is 10 feet 8 inches long by 9 feet in diameter, and the fourth is 
by Messrs. Praser & Eraser, also of the marine type, 13 feet long by 9 
feet in diameter. The smoke-box front of the latter is not provided with 
doors, but opposite each tube is placed a plug, which can easily be 
removed so as to allow of the tubes being cleaned if necessary without 
stopping the boiler. The working pressure of all the boilers is 150 lbs., 
and the average coal consumption per unit generated during the last 
quarter has been 5^ lbs. of Welsh coal, working condensing. 

"Water is supplied to the boilers by two Peam feed-pumps, which take 
their water from the condenser hot-well or from tanks placed over the 
pump-room and pump it through two Green economisers placed in the 
main-flue. The feed-water is thus heated to about 150 degs. Fahr. 
The water consumption is measured by a Kennedy water-meter placed 
between the pumps and the economisers. 



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THB WB8TMINSTBB BLBOTBIO SUPPLY CORPORATION. 225 

The engine-room is very lofty, and the walls are of white glazed brick, 
which give it a fine appearance. The office is placed in one corner, and 
next to it is a small testing-room. At one end of the room there are two 
Willans triple-expansion engines of the 1 1 size, developing 200 indicated 
horse-power at a speed of 850 revolutions per minute, and each of these 
drives direct a Crompton four-pole shunt-wound dynamo, developing 500 
amperes at 225 volts. The armatures of the dynamos are wound with 
stranded cable pressed into a suitable rectangular form. Both of these 
engines are fitted with the Willans and Robinson special cooling apparatus, 
consisting of pipes placed inside the crank-chamber in such a manner as 
to allow of cold water being passed through them, and it is possible to run 
the engines constantly without overheating the bearings. Nearer the 
centre of the room are placed two sets, each consisting of a Windsor high- 
speed vertical compound engine of the inverted open type, by Messrs. 
Davey, Paxman, & Co., of Colchester, and a dynamo. They are fitted 
with a Paxman patent automatic expansion-gear and adjustable high- 
speed governor, by means of which the cut-off can be varied from zero to 
five-eighths of the stroke. A heavy fly-wheel, 6^ feet diameter, and 
weighing two tons, is placed upon the end of the shaft opposite to the 
dynamo. The dynamos are of the Crompton four-pole type alluded to 
above, and develop 250 amperes at 220 volts. Two other small sets are 
placed in the comer of the engine-room ; each consists of a Willans com- 
pound engine of the G G size, giving 80 indicated horse-power at 430 
revolutions, with steam at 150 lbs. pressure. These drive direct two 
Siemens dynamos, each developing 400 amperes at 100 volts, but they 
can be run at a higher speed, and give 300 amperes at 135 volts for 
battery charging. These small dynamos are used for balancing. 

A new dynamo of 500 amperes and 225 volts, by the Electric Con- 
struction Corporation, coupled to an I I Willans engine will be added 
during the summer. 

The cables are carried from the machines inside bent gas-pipes 
embedded in the foundations, and thence up the walls. 

The foundations for all the sets consist of one large concrete block 
10 feet thick, which is perfectly free from the walls of the building, so as 
to prevent vibration of the structure. A 6 tons overhead crane serves 
the whole of the engine-room. 

The steam-pipes will eventually be arranged upon the ring system 
entirely round the engine-room, and at present are provided with stop 
valves, so as to cause as little hindrance as possible in case of accident* 
The spindles of the valves are vertical, with hand-wheels below, and the 

VOL. Y.— 1809-06. 1^ 



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226 THB WSSTVIFSTER ELBCTBIC SUPPLY CORPORATION. 

latter are cast in the form of a bowl, so that aU the leakage is oollected 
and may be nm off hj means of a small cock. The main steam-pipes, of 
steel, 8 indies in diameter, are fitted with wronght-iron screwed flanges. 
The copper branch-pipes are 5 inches in diameter. 

The exhanst steam from the engines can either escape np the chimney, 
which is 150 feet in height, having a 21 inches cast-iron exhanst-pipe np 
the centre, or can be condensed. A large snr&ce condenser, constructed 
at the Central Marine Works, Hartlepool, is placed in a space between 
the engine-block and the wall, aboat 10 feet below the engine-room level. 
It has 1,940 three-quarter inch tubes, 10 feet 6 inches long, giving about 
4,000 square feet of cooling surface. The air-pump has a plunger 18 
inches in diameter and 20 inches stroke, working horizontally, and driven 
by a connecting-rod from a compound vertical engine, with cylinders 6^ 
inches and 17 inches in diameter and 15 inches stroke. 

The switch-board, constructed by Messrs. Crompton & Co., consists 
of nine slate panels, and is a plug board. The regulating switches for 
controlling the charge and discharge of the cells are designed in a circular 
form. Each panel carries connexions for three machines and four feeders. 
That at the centre has at the top a pair of balancing switches, so that either 
of the 100 volt machines may 1^ connected to either side of the three- 
wire system. Underneath these are placed two voltmeters, that on the right 
giving the volts at the terminals of each battery separately by means of 
wall-plug connexions, that on the left giving the total volts of the two 
batteries in series. The plugs at each side connect the dynamos to the 
batteries. There are two voltmeters below for the small machines, two 
ammeters, two field-magnet resistance-switches for the small machines, 
and two automatic gravity-switches for breaking circuit to the batteries 
when the dynamos are slowing down. 

The next panel on the left, which is the negative side, carries a large 
regulating-switch at the bottom for a battery of fifty-six cells, and above 
it a large ordinary switch. The next panel to the left carries three auto- 
matic gravity-switches at the bottom, and an ampere-meter for each 
machine next above. The bars above these instruments contain plug 
holes, and are connected to the omnibus-bars at the back of the board. 
Four voltmeters for the pilot wires are above these, then the feeder-bars, 
and higher up the four ammeters for the feeders, each reading up to 500 
amperes, while at the top are placed the main fuses, consisting of ten 
wires soldered to copper ends; and duplicate fuses are so arranged that in 
case one is melted another can be instantly switched into the circuit. The 
next panel is similar. The panels upon the right of the centre carry the 



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QAS LIGHT AND COKE COMPANY. 227 

positive terminals, and are duplicates of those at the left, except that at 
the bottom are placed the field-magnet i*esistance-switohes, and above these 
the three voltmeters for the difference of potential between the tenninals 
of the dynamos. The joints are oval flanges of gun-metal, screwed and 
brazed upon the copper bars forming the mains. The flanges are carefully 
faced, and drawn together by bolts and nuts. Throughout the station the 
negative wires are all coloured red, the positive black, and the intermediate 
wires black and red in alternate rings. This colouring is the contrary of 
that used by some other companies, but Wilkes pole-finding papers are 
used for testing, and as these turn red when touched by the ends of the 
negative wire, it is easier to remember which is the positive and which the 
negative main. 

The main conductors in the engine-room consist of round copper bars, 
which are carried along the walls and supported upon wooden brackets, 
and glass insulators and supports of notched fibre. Two Aron electricity- 
meters, with the Miller reversing arrangement, are placed in the battery 
mains. An ordinary Aron meter is used for the station-lighting circuit, 
supported away from the wall, hexagon unions being used for the joints of 
the conductors. Each dynamo is provided with an Aron meter. The 
engine-room is lighted by two Edison-Swan lamps of 200 candle-power, 
and small lamps are used for the switchboard. 

The battery-room is upon the first floor over the boiler-house, contain- 
ing two batteries of the Crompton-Howell type, each consisting of fifty-six 
cells containing sixty-one plates. They have been discharged at the rate 
of 800 amperes per half -hour, although their stated capacity is only 500 
ampere-hours. The cells are supported upon wooden shelves resting upon 
iron columns, and the floor is of asphalte. Four «xtra cells in each 
battery are used as milking cells, in order to rectify any extra loss in other 
cells. 

The third central station, situated in Millbank Street, "Westminster, 
supplies the Houses of Parliament and the important district including 
the Government Buildings in Whitehall, and Victoria Street as far as 
Victoria Station. 



GAS LIGHT AND COKE COMPANY. 

Beckton, or " Beck Town " (so called in honour of a former governor 

of the Gas Light and Coke Company, the late Mr. Simon Adams Beck) is 

situated in the Essex marshes at a point towards the lower end of Galleons 

Beach of the River Thames, and about ten miles east of London. The 



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228 GAB LIGHT AND OOKE COMPANY. 

oompany'B old works, Ijing almost in the heart of London, did not admit 
of extension ; and when larger premises became necessary, it was con- 
sidered that the cost of coal delivery might be greatly reduced if the works 
were removed some distance lower down the river, so as to avoid the 
expense of barging and cartage ; while at the same time, by having plenty 
of land, there would be ample space for the storage of such residuals as 
coke, tar, and ammoniacal liquor. The present site having been secured, 
the first pile of the new works was driven on November 19th, 1868, in an 
uninhabited marshy swamp ; the works were put in operation on November 
25th, 1870; and with the extensive additions made since that date 
Beckton may now be described as a town in reality, as well as in name. 

The pier forming the approach to the works from the river is a 
wrought-iron structure supported on cast-iron cylinders, having a frontage 
parallel to the river of 800 feet, and projecting forwards 400 feet from 
the shore into the river. It affords berthing acconmiodation for four 
steam-colliers of the largest size ; and for discharging their cargoes each 
berth is provided with three steam or hydraulic cranes and a movable 
steam-crane : the unloading power being fully equal to 12,000 tons in 
twenty-four hours. There are two jetties, and, in addition, ample quay 
accommodation for smaller craft. An additional pier, with connecting 
viaducts and railways, equal in size and capacity to the existing one, is in 
course of erection. 

On reaching the shore, the pier joins a viaduct on the same level and 
forming a continuation of it. At the point of junction four branches 
start from the main viaduct, two running along the right-hand side 
through a series of six retort-houses, and two along the left-hand side 
through a similar set of six retort-houses. The main viaduct, which has 
a double line of rails, runs along the whole length of the space between 
the two sets of retort-houses, a distance of three-quarters of a mile from 
the river to the end. 

The retort-houses are all very much alike. The largest is 510 feet 
long by 100 feet wide, and is capable of producing 5^ million cubic feet 
of gas per day. Running through the house on either side are high and 
low-level railways of standard gauge ; the high-level railway is used for 
conveying coals from the steamers alougside the jJier to the coal-stores 
within the house, aud the low-level railway is used for taking away the 
coke drawn fix)m the retorts. Locomotives and iron wagons are employed 
on these railways. In the largest house there are forty-five beds, each 
containing nine fireclay retorts of 20 feet length, making a total of 405 
retorts. £ach retort-house has a complete set of purifying and other 



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GAS LIGHT AND 00KB OOMPANY. 229 

plant attached to it ; so that the Beckton works may be said to be made 
up of fourteen complete gas works, the smallest of which is of no mean 
calibre. 

The coals are delivered into stores which are conveniently placed in the 
retort-house, so that the retorts may be readily charged from them. Each 
retort is charged with about 6 cwts. of coal every six hours. The mouth- 
pieces of the retort are securely closed up with iron lids. The gas as it is 
distilled from the coal passes up through vertical pipes, fixed at each end 
of the retort, into a long wrought-iron vessel, rectangular in section, placed 
on the top of the retort-beds, called the hydraulic main ; its principal 
purpose is to serve bs a self-acting valve for shutting off the gas when the 
mouthpieces are opened for charging and discharging the retorts ; and it 
is also here that a large proportion of the tar is thrown down, and some 
ammoniacal liquor. When a charge is burnt off, the lids are opened, and 
the remaining coke is drawn out and deposited on the floor beneath the 
charging-stage. A. portion of the coke is used for keeping up the heat of the 
retorts, and the remainder is loaded into wagons and taken away for sale. 

The gas is withdrawn from the hydraulic main by exhausters, and is 
next passed through a series of horizontal cast-iron pipes 12 inches in 
diameter, called condensers, around which the air is allowed to circulate 
freely. In this apparatus the tar and ammonia travelling with the gas 
from the retort-house are condensed, and are run off into storage-tanks. 

The gas issuing from the condensers is still very foul, for although 
nearly all the tar is eliminated, it still contains a considerable quantity of 
anmionia, carbonic acid, and sulphuretted hydrogen. To absorb these it 
must be propelled through washing or scrubbing-vessels. The scrubbers 
are generally in the form of circular towers, about 60 feet high, con- 
structed of cast-iron plates, and filled with coke broken to a convenient 
size ; brushwood is placed on the top to act as a distributor for the liquid. 
The foul gas entering at the bottom of the scrubbing tower and ascending 
through the coke is met by weak ammoniacal liquor or clean water per- 
colating through the fine interstices of the brushwood, whereby the whole 
of the ammonia remaining in the gas is absorbed ; and the combination is 
ammoniacal liquor, with which some carbonic acid and sulphuretted 
hydrogen are also taken up. 

The gas has next to pass through eight purifying vessels in the follow- 
ing order : — First, through two vessels containing clean carbonate of lime, 
which removes the whole of the carbonic acid left in the gas; next 
through two vessels containing oxide of iron, which cleanses it of sul- 
phuretted hydrogen ; thirdly, through two vessels of lime that has been 



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230 MESSRS. MAXJBSLAT, SONS, AND FIELD, LIMITED. 

previously sulphuretted, which removes the greater part of the bi-sulphide 
of carbon ; and finally through two more vessels charged with clean lime, 
by which all traces of sulphuretted hydrogen are eliminated. The gas 
being now as pure as it is possible to make it, and of the required illumin- 
ating power, is in a fit state to be delivered for consumption ; but before 
this is done, it is first measured through large station-meters, and stored 
in gas-holders, from which it is pumped out as required. For this 
purpose there are nine gas-holders at Beckton,* from which, by means of 
twelve large Beale rotary gas-exhausters (eight capable of pumping 260,000 
cubic feet, and four 350,000 cubic feet per hour, making a total of 
3,400,000 cubic feet per hour), the gas is propelled along two cast-iron 
mains 48 inches in diameter, from Beckton to Westminster, picking up 
from other stations on its way, and filling up other gas-holders along the 
line of route. 

It may be mentioned that the company have eleven manufacturing 
stations in all, situated in various parts of the metropolis and suburbs ; 
and the quantity of coal carbonized annually is about 2 millions of tons, 
of which about one-half is consumed at Beckton alone. 



MESSRS. MAUDSLAY, SONS, & FIELD, LIMITED. 

The following work was seen in progress : — 

Single-screw engines for H.M.S. "Monarch," of 8,000 indicated 
horse-power, having a high-pressure cylinder 49 inches in diameter, 
intermediate 74 inches in diameter, and low-pressure 112 inches in 
diameter, and 4J feet stroke. 

Twin-screw triple-expansion engines of 3,500 indicated horse-power 
for H.M.S. " Dryad," building at Chatham, having cylinders 22, 34, and 
51 inches in diameter, and If feet stroke. 

Twin-screw triple-expansion engines of 5,000 indicated horse-power, 
for the Russian cruiser " Admiral OusbakofF," building at the Baltic iron 
shipbuilding yard at St. Petersburg. The cylinders are 31, 46, and 68 
inches in diameter and 2J feet stroke. 

Three sets of single-screw engines for first-class torpedo-boats, built 
by Mr. White, of Oowes, for the Admiralty. 

Single air-compressors for compressing air for the torpedo service on 
shipboard. 

Also sundry small engines and gear in connexion with the foregoing 
work. 

* The largest of .which ia of a capacity of 8 million cubic feet. 



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TEAN8ACTI0NB. 281 



NORTH OF ENGLAND INSTITUTE OP MINING AND 
MECHANICAL ENGINEERS. 



GENERAL MEETING, 

Held in the Wood Memobial Hall, Nbwoabtle-upon-Ttnb, 

June 10th, 1893. 



Mb. J. B. SIMPSON, Pbebidemt, in the Chaib. 



The Sbcbetaby read the minutes of the last General Meeting, and 
reported the proceedings of the Council at their meetings of May 27th 
and of that day. 

The Secretaby read the Balloting List for the election of officers for 
the year 1898-94. 

The following gentlemen were elected, having been previously 
nominated : — 

Membebs— 

M£ H. M. Becheb, Mining Engineer, 9, IKAlmeida Street, Singapore. 

Mr. J. C. S. Bbynon, Civil and Mining Engineer, P.O. Box 1S64, Johannes- 
burg, TransTaal. 

Mr. Geoboe Davey, Mining Engineer and Metallurgist, Ferro-carril Michoa- 
can J Pacifico, Marayatio, Mexico. 

Mr. Stanley H. Fobd, Mine Agent, Stolzenfels, Great Namaqualand, South 
Africa. 

Mr. Thomas Gilohbist, Mining Engineer, Manor House, Penshaw. 

Mr. Geobge Linday, Colliery Manager, Blackett Colliery, Haltwhistle, 
Northumberland. 

Mr. William Ebnest Lishman, M.A., Viewer, Bunker Hill, Fence Houses. 

Mr. J. S. QniBK, Metallurgist, St. Helens Lead Smelting Works, St. Helens, 
Lancashire. 

Mr. F. Geobge Shaw, Mining Engineer, London. 

Mr. Edmund Spabgo, Mining Engineer, 3, Cable Street, Liverpool. 

Mr. Chables Robebt Westebn, Engineer, Broadway Chambers, West- 
minster, London, S.W. 

Mr. Joseph Henby Wooloock, Civil and Mining Engineer, 49, Lowther 
Street, Whitehaven. 

Associate Membebs — 
Mr. G. A. Febguson, Editor of the Mining Journal, 18, Finch Lane, 

London, E.C. 
Mr. Henby M. James, General Manager, Colliery OflSce. Whitehaven. 
Mr. Habby Page Woodwabd, Government Geologist, Perth, Western 

Australia. 



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232 TEANSACTIONS. 

Associates— 

Mr. Jambs Batnbbidob, Under Manager, North Walbottle Colliexy, 
Newcastle-upon-Tyne. 

Mr. RoBEBT Embbson, Engineer, Tudhoe Colliery, Spennymoor. 

Mr. Alezakdeb A. Jambs, Under Manager, Croxdale, near Durham. 

Mr. John W. Thompson, Colliery Surveyor, Backworth Colliery, Newcastle- 
upon-Tyne. 

The following gentlemen were nominated for election : — 

HONOBABY MbMBEB — 

Professor John Hebman Mbbivalb, Professor of Mining, Durham College of 
Science, Newcastle-upon-Tyne. 

Membebs— 

Mr. Abghibald Thomas Bbown, Mining Engineer, 372, Flinders Lane, Mel- 
bourne. 

Mr. Westoabth Fobsteb Bbown, Mining Engineer, Alston House, Parade, 
Cardiff. 

Mr. RiCHABD ECK, Mining Engineer, Beaconsfield, South Africa. 

Mr. Joseph Qouldie, Mining Engineer, Rimberley, South Africa. 

Mr. Joseph Habobeaves, Colliery Manager, Gwaun Cae Gurwen Collieries, 
Brynamman, B.S.O. 

Mr. John Holt, Jun., Civil and Mining Engineer, The Hollies, Heywood, 
Lancashire. 

Mr. Edwabd Hoppeb, Engineer, c/o Messrs. Lewis & Marks, Coal Mines, 
Yereeneging, Transvaal. 

Mr. John Wilson Richmond Lee, Mining Engineer, Potes, Proyincia de 
Santander, Spain. 

Mr. J. B. Robinson, Mining Engineer, Hedley Hill Colliery, Waterhouses. 

Mr. Walteb Rowley, Mining Engineer, 20, Park Row, Leeds. 

Mr. Thomas Bibch Fbeeman Sam, Mine Manager, Adjah Bippo, West Coast, 
Africa. 

Mr. Joseph Scott, Mining Surveyor, Newcastle Street, Stockton, near New- 
castle, New South Wales. 

Associate Membeb— 
Mr. Gbobge Thomas Duncan, Engineer and Agent, 110, Dilston Road, New- 
castle-upon-Tyne. 

Associates— 
Mr. Evan Cockbubn, Back Overman, Page Bank Colliery, via Willington, 

Co. Durham. 
Mr. William Hendbbson, Engineer, Wheatley Hill Colliery, via Trimdon 

Grange. 
Mr. Moses Hobson, Under Manager, Shildon, via Darlingtod. 



Mr. Edward Halse read the following paper on "The Gold-bearing 
Veins of the Organos District, Tolima, U.S. Colombia." 



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ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 288 



THE GOLD-BEARING VEINS OP THE ORGANOS DISTRICT, 
TOLIMA, U.S. COLOMBIA. 



By EDWARD HALSB. 



Introduction. 



Organos is a small Indian village lying in a valley near the pass of 
Chifldn,* one long day's mule-ride south-west of Aipe, and about the 
same distance north-west of Neyva — ^both towns on the upper Magdalena 
river. Savanilla is the port for this river, which runs between the eastern 
and central Cordilleras of the Andes northward to the Caribbean Sea. The 
Magdalena river is navigable for light-draught steamers as far as Honda 
(650 feet above the sea), where the first rapids are met with, a distance 
of about 550 miles from the coast. Above Honda smaller steamers ascend 
to Girardot, the port for the capital, Santa F^ de Bogotd (8,800 feet) on 
the eastern side, and for Ibagu6 (4,800 feet) on the western side ; and, 
during the wet season, to Neyva (1,200 feet), about 700 miles in the 
interior. 

The Andes in Colombia are divided into three ranges or Cordilleras. 
These are spread out considerably northward, but run close together to 
the south. The central cordillera is far excellmcey the metalliferous one. 
The mines of the Organos district are situated on its eastern flank. To 
reach these from the Magdalena river one has to cross the Chifl6n Pass 
over a singularly bold and serrated range running north-and-south to the 
west of Aipe and Neyva. The range, rising from 7,000 to 8,000 feet above 
sea-level, is composed of highly-inclined beds of a hard red conglomerate 
alternating with sandstone, whose trend is parallel to the axis of the 
range, and whose dip is eastward. The formation is said to be of Triasaic 
age. 

Owing to the hardness of the rocks and the steepness of the mountain- 
sides, the road over the Chifl6n Pass is one of the worst in Colombia, bad as 

* A ehijldn is (1) stagnant water into which a stream faUs with noise ; (2) a 
wooden pipe or flnme ; (8) a mining term, trahajar chifldn, is work making way in 
length and depth. 



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284 ORGANOS DISTRICT, TOLIMA» U.S. COLOMBIA. 

the roads of that country generally are ; and mules laden with cargoes not 
infrequently slip down the western slope, and are lost in the ravines below. 
Prom the top of the Chifl6n Pass a splendid view of the surrounding 
country is obtained. Eastward one looks down the forest-clad side of the 
mountain, dotted below with magnificent royal palms {palmas reales) and 
other tropical trees, across wide plains down the centre of which the Mag- 
dalena river winds, until the eye rests upon the eastern Andes, blue and 
hazy in the distance. Westward the topography is entirely different. In 
this direction one looks upon a sea of almost treeless hills, backed by forest- 
clad mountains towering one above the other, the whole forming part of 
the eastern flank of the central cordillera. The hills in the foreground, 
covered only with grass and small shrubs (except in the valleys and gullies, 
the lower portions of which are more or less densely clothed with vegeta- 
tion) form steep and narrow ridges, trending north and south, flanked by 
knife-edged cordons or ribs (cuchillos) oblique or perpendicular to them, 
which in their turn are strongly ribbed in a direction perpendicular to 
their length. Thus between the ranges are narrow winding valleys or 
canadas, down the moderately-sloping bottom of which a river or strong 
stream of water usually courses, and between the lateral cordons are steep 
gullies or quehrados opening into the valleys on either side, down which 
torrents of water flow in the wet season. 

The formation consists of crystalline eruptive rocks and metamor- 
phosed schists. Of the former granophyre,* felsite, and hornblende- 
dolerite, in bedded masses and in dykes, predominate. The granophyre 
and felsite are generally moderately hard, and of a pale green colour. 
They are in places stained red with oxide of iron, and are frequently 
altered to a soft white clay resembling kaolin. The dolerite is usually 
very hard, and of a darker green — in places this rock too is soft and 
decomposed, but it usually retains its colour. Wherever observed it is 
strongly charged with iron pyrites. It is chiefly from the rapid erosion 
of some of the beds that the hills derive their peculiar topography. 

The metamorphic rocks, usually consisting of chloritic schists and slates, 
are seen at the base of some of the hills, and form the major portion of 
others. 

The schistose rocks in the State of Tolima have been variously described 

* A mixture of orthoclase-felspar and quartz which have simultaneouslj con- 
solidated. These rocks in the Organoe district were formerly called sandstone. 
Sections cut of typical specimens of the country have been examined and named by 
a well-kown petrologlst. Some exhibit beautiful examples of the structure known as 
granophyric. 



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ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 285 

as of Silurian, Oambro-Silarian, and Laurentian age. These and the erup- 
tive rocks overlying them are most probably Pateozoic, but so far in suf- 
ficient data have been collected to determine their exact age. It appears 
that when the central cordillera was upheaved at the close of the Triassic 
or commencement of the Jurassic epoch, these beds, breaking through the 
Triassic sandstones overlying them, were forced up to the surface, and were 
considerably contorted during the process. The formation in places 
exhibits evidence of a good deal of confusion ; the strike and dip of the 
beds vary considerably, and at short intervals ; they are also much jointed 
and fissured, and are moreover permeated by felsitic dykes. 

Here and there in the eruptive rocks are lenticular masses of schistose 
rocks, and the former appear to merge imperceptibly into the latter, so 
that possibly the rocks called eruptive are the result of extreme metamor- 
phism of sedimentary rocks brought about by long-continued pressure, 
heat, and aqueous action. 

A number of veins have been found traversing the rocks in various 
directions— the prevalent one being nearly east and west — and containing 
quartz with visible gold associated with manganese and oxide of iron near 
the surface, and with iron pyrites, galena, etc., below. The gold above 
the water-level is extremely patchy, and visible gold is by no means 
the sign of a rich vein, for it is seen here and there in veins whose 
average only runs a few pennyweights to the ton. Some of the veins 
run into and continue through the schistose rocks, and appear to be of 
more stable nature therein. Some veins are very rich, especially at and 
near the surface, carrying gossan with from one to several ounces of gold 
to the ton for a certain distance, which seldom amounts to many yards 
either in length or depth, and then a fresh vein has to be sought elsewhere. 
Mining in this will-o'-the-wisp style was carried on for some years, and 
has only recently given place to something approaching to system ; but as 
the water-level has not yet been reached, the problem has still to be 
solved whether the veins are sufficiently auriferous to be worked profitably 
for any long period of time. 

So far as the writer is aware, a description of this district has never 
yet been published. Sefior Vicente Restrepo, in his very interesting 
work* on the Colombian mines, mentions only the fact that numerous 
gold and silver veins occur here, and that in Constancia one only was 
then being worked containing rich ore, but scarce. 

* Egtudio wbre las mintu de oro y plata de Colombia^ second edition, 1888, page 99. 
Translations of this work have appeared in English and French. 



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236 OR6AXOS DISTRICT, TOLIICA, TA, COLOXBUL 

The Teins may be classified as follows : — 

1. Bedded or Begregated veins {Lagergantj^) of rich amiferoos 

quartz or goasaiu 

/^FsnaDy of shallow depth 

2. (a) Veins of rich anriferoos gossan \ and nncertain length : 
(b) Veins of rich anriferoos quartz i ther mar be termed 

snperficial fisEnie-Tdns. 

3. Anriferons fincanj joints. 

4. Quartz fissore-Teins carrying free-gold near the surface, and 

anriferons pyrites below. 
Classes 1, 2, and 8 generaUy occur in the eruptive rocks only, while 
daas 4 occurs both in the eniptive and sedimentary rocks beneath or 
adjacent to them. 

1. — AuBiFKBOUs Bedded Vbixs or Seams. 

Typical veins of this class are seen at the Chorro working of the 
Gonstancia mine, where a big open cat has exposed several of them, and 
from which a fair quantity of gold has been raised. Fig. 1, Plate IX., 
is a section of one of these auriferous quartz-seams which, at the point 
examined, is from 6 to 18 inches thick, and suddenly changes in dip 
from almost horizontal to nearly vertical. It appears to be in reality a 
somewhat complex case of a saddle-reef. The country here is decom- 
posed granophyre stained with iron and manganese, some of whose layers 
are seen to end abruptly against one wing or leg of the saddle. Such 
contortions are local in character, and the veins much more frequently 
have the appearance of Figs. 2 and 3, Plate IX. In the former case the 
vein is about 1 foot wide, consisting of quartz in two layers lying on a 
thin stratum of rock veined with quartz, oxide of manganese, and ochre. 
The true floor is altered, ochre-stained granophyre, while the roof is 
still softer, being composed of ochieous and manganiferous clay. 

The quartz-layers are apt to merge suddenly on either side into 
rock, leading to the inference that they were formed by replacement. 
The quartz contains iron pyrites in its cavities, and sometimes clay and 
gold, as well as blende and galena stained with oxide of iron. The gold 
in these seams is generally visible, and sometimes coarse. It is irregularly 
distributed, and some very rich specimens can be found. 

The bedded veins run from nearly east and west* to a little west of 
north, and dip about 60 degs. south or west respectively (variation 48 d^. 

* All bearings magnetic, 1888. 



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OBQANOS DI8TBI0T, TOLIMA, U.S. COLOMBIA. 287 

to 70 degs.). The direction of one bed here is north 35 degs. east to 
south 85 degs. west (dip south-east 48 degs.), which is nearly normal as 
regards both strike and dip. 

A slickenside joint clearly marked, being stained with black oxide of 
manganese, is sometimes visible in the clay forming the roof (Fig. 8, 
Plate IX.). It was noted that the lines are not parallel with the dip, 
but make an angle of about 10 degs. with it, and also that in places there 
is a want of parallelism among the lines themselves. The seams are 
crossed perpendicularly by some joints also showing slickensides. As will 
be seen from the section (Fig. 8) the country adjacent to or separating 
the quartz-layers is decompQsed to a clay. 

In places the rock shows evidence of a schistose structure, but this 
matter will be referred to again when treating of veins of class 2. 

At the Silencio mine at least two bedded auriferous quartz-veins are 
seen to crop out on the face of a very steep hill. The lower one is the 
richer and can be traced for about 100 yards along the surface. The 
outcrops as exposed on the hillside form an angle of about 25 degs. with 
the horizon. The chief bedded vein rune about north 8^ degs. west to south 
8^ degs. east, and dips west 80 degs. to 48| degs., or against the hill. 
The average width of the vein is 2 feet, but the rich auriterous quartz- 
leader is seldom more than 6 inches thick, the rest of the vein being 
composed of smaller layers of quartz divided by country. The quartz 
varies in structure from solid to sugary, and is spotted with iron pyrites, 
manganese, oxide of iron, clay, etc. Visible gold is of common occurrence 
in certain parts of the outcrop. In a piece of highly auriferous quartz a 
single crystal of haematite was found. The vein was sunk upon in one 
place — the dip changed from 30 degs. at the surface to 48 J degs. below — 
the quartz quickly wedged out a few yards from the surface and with it 
the gold, giving place to a clay or flucan. The latter was followed down to 
a depth of about 100 feet on the dip, when the sinking was stopped, as no 
further ore had been met with. The veins vary in richness from about 
8 dwts. to 3 ounces of gold to the ton, and are usually rich or poor on the 
same horizon. 

At the Socorro mine a bedded vein has been partially worked, which 
in one place has the section shown in Fig. 4, Plate IX. It appears to 
be a trough or inverted saddle-reef. The quartzose seam merges in places 
into ferruginous rock, and some layers of the country with thin seams of 
quartz end abruptly against one wing or leg of the trough. In neither 
of the peculiar contortions figured is there evidence of a saddle or trough- 
joint. 



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2S8 ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 

2.— (a) Veins of Auriferous Gossan. 

At the Te Encontr^* workings of the Constancia mine there are several 
examples of this class of vein in quartz-felsite. They are remarkable for 
their very singular appearance (Figs. 6 to 10, Plate IX.). They trend 
usually a few degrees north of east, and dip south, and, as a rule, are 
auriferous to no great extent either horizontally or vertically. They 
appear to be especially auriferous when crossing certain manganiferous, 
ferruginous, and ochrey layers of the country (Figs. 5 and 6), which 
strike a little west of north, or perpendicular to the veins, and against 
certain wedges or horses of schistose rock found in the felsite (Figs. 7 
and 10). 

The ore is generally gossan or earthy brown oxide of iron, which 
frequently contains visible gold. The centre of the vein is sometimes 
composed of crystalline quartz. The precious metal is also found in the 
manganiferous and ochrey layers on the sides of the vein, and even for 
some little distance therefrom. These veins are extremely irregular, having 
no defined walls, although generally a southerly dip is roughly traceable. 

Immediately above the section shown in Fig. 7 is a layer of soft 
manganiferous rock 1 foot thick. In Fig. 8 the vein consists of a rich 
auriferous band of gossan from 12 to 15 inches thick. It is nearly 
vertical, the south wall being defined by a thin seam of clay or flucan, 
while no joint occurs on the north side. The vein in all has three nearly 
vertical seams of clay crossing others dipping fiatly to the south ; the latter 
appear to have slipped down a little on the south wall of the vein. 

The felsite country rock often has a brownish mottled appearance. 
Under the microscope it is seen to be traversed by minute stringers of 
quartz. 

At the Socorro mine some thin but extremely rich veins of this class 
have been met with, consisting of a few inches of light brown gossan 
showing visible gold in the broken surfaces and assaying 50 ounces of 
gold to the ton and upwards. 

At the Silencio mine several veins of the same class occur in grano- 
phyre. One trends on an average east 13^ degs. south to west 18^ degs. 
north, and dips south 66 degs. to 68 degs. At the surface it is about 
1 foot thick, with from 2 to 4 inches of brown gossan on the hanging-wall, 
the rest of the vein being soft altered granophyre with hard lumps of 
quartz, country, and oxide of iron here and there. Ten feet down the 
vein shows iron pyrites, with oxide of iron, and quartz in lumps. It was 

* Literally, ** I have found thee ! " the exclamation of the miner who discovered 
the first rich vein in this district. 



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ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 289 

proved by a cross-cut driven in 20 feet vertically below the outcrop. 
When cut it was found to be disordered by a slide, and consisted of gossan 
and quartz with well-defined walls having a regular dip. The mineral 
showed visible gold, and gave an excellent colour in the batea. West- 
ward it was split into two branches by a horse of rock — the branches 
together made 8 inches of rich gossan (Fig. 9). In this instance the 
country was intersected by joints more or less parallel to the vein, and 
dipping in the same direction at an angle of 45 degs. The ore in one 
spot made against a bed of dark stained rock (altered schist ?) as in 
the Constancia mine (see Fig. 10, and compare Fig. 7). Westward the 
vein was cut out 24 feet from the cross-cut ; eastward, although the joint 
was straight and well-defined, the vein 20 feet from the cross-cut consisted 
only of 4 inches of auriferous gossan. A second cross-cut was run in from 
the surface in order to ascertain if the vein went down. But nothing was 
cut, not even a pronounced joint, and yet the vein was traceable on the sur- 
face for about 100 feet in length. 

2.—{b) Veins of Auriferous Quartz. 

At the same mine, a vein believed to belong to this class intersects the 
bedded veins of gold-bearing quartz already described as running north 
8J degs. west, and dipping west. The vein trends north-east to south- 
west, dips south-east from 80 degs. to 60 degs., and consists of what 
is known locally as formacion, or country altered to a clay (the cascajo of 
Venezuelan, the mullock of Australian, and the hUff of American miners). 
At the junction it was 1 foot wide, and when driven on into the hill in a 
south-westerly direction the vein was double in size, and had much improved 
in value. Fig. 11, Plate IX., shows the appearance of the vein some little 
way in. The fortnacion here consists of decomposed granophyre, mottled 
red, yellow, white, and brown, and containing native gold in crystals. 
The quartz was fairly spangled with gold, almost every stone broken 
showing the precious metal ; but very loose, and in exceedingly thin plates 
and fine grains. The gold was easily shaken out of the specimens, and 
appeared to have been deposited quite recently. A sample taken, not 
showing visible gold, gave 1 oz. 8 dwts. of gold to the ton. The decom- 
posed rock in the vein gave a good colour in the batea. 

Farther in the vein showed a tendency to split up (Fig. 12, Plate IX.), 
and was less rich. However, the vein has since been driven on for a 
length of 65 feet, the formacion carrying gold, and increasing in width 
with stringers of ore. A rise was put up 43 feet to the surface ; for 28 feet 



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240 OBGANOS D18TBICT, TOLIMA, U.S. COLOMBIA. 

the vein was very rich in gold, and from 2J to 4^ feet thick, the last 
16 feet consisting of fonnacion carrying gold and intersected with stringers 
of quartz to within a few feet of the surface. 

The vein was sunk on 26 feet, the lode, including formacion, was from 
8 to 8 J feet wide with solid quartz from 1 to 2 feet wide. For a time 
the lode improved in depth; every stone broken showing visible gold. 
Nevertheless the writer believes that eventually the vein gave out both in 
length and depth. 

This vein, consisting as it does of quartz and altered rock (formacion), 
and containing little or no gossan, seems to form a class of its own. 

8. — AuBrpEBous Flucant Joints. 

The only auriferous joints observed by the writer in this district are a 
few at the Socorro mine. These run east 19 degs. north to west 19 degs. 
south, and are vertical, or dip sharply to the south. The joints bear clay 
and native gold, but are auriferous to only a very limited extent. They 
possess features of no particular interest. 

4. — AUBIFEBOUS QUABTZ FiSSUBE-VBINS. 

These veins are found traversing the eruptive and metamorphic rocks 
indiscriminately. Two veins of this class cross the bedded veins of Chorro, 
one trends north-west with a high dip, is 27 inches thick, and consists of 
quartz, and red, yellowish, and black-stained rock ; the other vein strikes 
east 22^ d^s. south to west 22 J degs. north, and in one portion is filled 
with clay and oxide of iron rich in gold, while in another it is 2 feet 
wide, and is filled with quartz, clay, and iron pyrites. 

At the Socorro mine one vein which has been proved near the sur&ce 
for about 200 feet in length occurs in more or less altered granophyre. 
The average run of the lode is east 26 degs. north to west 26 degs. south, 
the average dip south 72 degs., and the average width 8 feet. The strike 
varies from east 16 J degs. north to east 85 J degs. north, the dip from 
62 degs. to 82 degs., and the thickness from 4 inches to 6 feet. In the 
granophyre the contents are chiefly auriferous oxide of iron and quartz in 
leaders, separated by more or less altered rock (Fig. 18, Plate IX.). 

About 100 feet below the outcrop the lode passes into hard homblende- 
dolerite — ^possibly an altered schist; the dip changes from 72 degs. to 
82 degs., and the lode is characterized by bands of iron pyrites, galena, 
quartz, and hard country rock — the latter either dead, or with some 
calcite, quartz, and iron pyrites. Each wall is marked by a well-defined 
ferruginous joint, but without any clay selvage. Fig. 14, Plate IX., shows 



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OBGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 241 

the structure. A joint or bedding-plane striking north-west, dipping 
south-west, and crossing the lode near the hanging-wall, is probably the 
feeder of the lode at this point. The country next to this tirall is sprinkled 
with iron pyrites, and contains calcite in large crystals. 

The mineral from this portion of the lode, hand-picked, yielded 6 
ounces of gold to the ton and upwards, and paid to export to Swansea. 

The trend of the lode in the moderately hard rock, and where rich, is 
east 17 degs. north — ^this is the useful bearing of the lode — but in very 
hard rock met with farther west the trend becomes more northerly or east 
85 degs. north (angle of horizontal bending = 19^ degs.), the dip changes 
to north 80 degs. (angle of vertical bending = 18 de^s.), and the lode is 
impoverished. Furthermore, a cross-joint is met with here, which has the 
effect of cutting off the mineral contents almost entirely. Harder rock is 
met with in the stopes also in this direction, and the lode is poorer; but a 
few hundred feet farther west some rich quartz from 1 to 2| feet in width 
is found in the lode near the surface (rock : decomposed granophyre), where 
the trend and dip correspond to that of the richer portion of the lode in 
the dolerite. 

A cross-cut driven north-west through the country in this part of the 
mine discloses purple beds of quartzose schists trending north-west to 
south-east and dipping south-west, followed by a dyke of hard dolerito 
dipping northward, which is succeeded by altered granophyre. Here 
and there also in the schists occur patches of the latter rock. 

At Te Encontr^, a lode has been proved for about 600 feet in length 
and 182 feet in depth in quartz-felsite. The average run of the lode 
is east 9 degs. north to west 9 degs. south, and the average dip south 
68 degs. The angle of total divergence in strike is 81^ degs , and in dip 
49 degs The average width was 5 feet, varying, however, from 6 inches 
up to 6 feet. In the No. 1 and No. 2 levels, the rock is quartz-felsite, 
often much altered, and the vein consists of ferruginous quartz with free- 
gold. In the No. 8 level, however, the rock is dolerite, which becomes 
very soft in the No. 4 or bottom level. 

In No. 8, where the rock is moderately hard dolerite, the lode is about 
6 feet thick, half of this being well impregnated with galena and iron 
pyrites, the latter being scattered all through the lode. The galena is 
argentiferous and carries some gold, but the iron pyrites is much more 
auriferous. The effect of a flucan crossing the lode in one of the stopes 
is to flatten it considerably (Fig. 1 5, Plate X.). At a, the vein was con- 
tinued inside the day flucan itself, as an irregular mass of auriferous 

16 



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242 ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 

and ferruginouB quartz. In the No. 4 level, or 182 feet from the surface 
(measured vertically), a cross-course has thrown the lode 110 feet to the 
north. On the west of the cross-course, the lode is 4^ feet wide in a soft 
green rock with joints having polished surfaces (altered dolerite) sparsely 
sprinkled with iron pyrites. The dip is south 79 degs. The lode to 
the east of the cross-course is quartzose, from 12 inches to 2 feet thick, 
and poor in gold. 

About 12 feet south of the western portion of the lode in No. S, a vein 
of quartz 2 feet wide and dipping south is seen on the walls of the 
cross-course, and 24 feet farther south is another vein of quartz, somewhat 
auriferous. As these veins pass through the cross-course they would 
appear to be of more recent date than the latter. 

Hence in this mine we appear to have evidences of : — 

1. An older east and west fissure. 

2. A newer north and south cross-course. 

3. Newer east and west fissures. 

About 200 yards east of this, a parallel vein was discovered of 2 feet 
of white sugary and friable quartz, showing here and there minute specks 
of native gold. Notwithstanding the favourable appearance of the quartz, 
the yield was only a few pennyweights to the ton. It was considered likely 
that most of the gold had quite recently been leached out of the vein. 

At Silencio, a vein of this class, traceable for 600 feet along the 
surface, has been worked 400 feet in length at a depth of about 100 feet 
vertical from the surface. The average strike, dip, and width are 
east 29 degs. south to west 29 d^. north, south-west 62*5 degs., and 
2 feet respectively. The rock on the 100 feet level is in the main hard 
granophyre. The lode was widest (4 to 6 feet) and richest when the 
strike was north 42^ degs. west or north-west nearly, but to the north of 
this point a branch falls into the lode on the hanging wall, and near the 
centre of the run of ground, a non-auriferous quartz- vein trending nearly 
east and west and dipping south, crosses it obliquely. The lode was formed 
of one or more layers of quartz sprinkled with iron pyrites and galena, 
and showing here and there crystals of blende. The quartz was generally 
of somewhat transparent crystalline structure, occasionally sugary, and 
frequently stained red in the joints. It was colourless, or had a brownish 
tinge. Sometimes the quartz was light bluish. Here and there it con- 
tained visible gold, but the latter was no real indication of richness. The 
gold contents varied from a few grains to several ounces to the ton, A 
milling test of several hundred tons yielded about 4 dwts. to the ton. 



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0RGAN08 DISTEICrr, TOLIMA, U.S. COLOMBIA. 248 

and as 1 dwt. was found in the tailings,' the average gold contents were 
only j; ounce to the ton. 

Just beyond the point where the lode was widest it split up into two 
branches : that on the southern side consisted only of a few inches of 
unproductive quartz, while the northern branch consisted of about 6 
inches of auriferous and pyritic quartz. The hanging-wall appeared to 
be a schistose rock, the footwall being brown granophyre. In some points 
the schistose rock was on the footwall, but it was more generally on 
the hanging wall. The leader sometimes lay on the hanging wall, but it 
was more of ten a little distance from it, and sometimes having a much 
flatter dip, it gave the lode a wedge-shaped appearance as seen in section. 
Pigs. 16 to 20, Plate X., represent the appearances assumed by the lode 
in this part of its course. By comparing Pigs. 16 and 17 (the latter is 
from a point about 1 foot north of the former) it will be seen that a band 
of rock highly charged with iron pyrii^es has become a band of quartz 
charged with the same mineral ; this appears to be an instance of local 
replacement. 

It has been observed that in certain distncts galena is a good indi- 
cation for gold.* In order to ascertain whether the galena contained the 
precious metal, the writer made (1) an assay of the quartz "well spotted 
with this mineral, the result was 9 dwts. of gold to the ton ; (2) an assay 
of galena carefully picked out from the quartz resulted in 45 ounces of 
silver and 2 dwts. of gold to the ton. As the concentrated sulphides in the 
vein yielded nearly 16 ounces of gold to the ton, the result was arrived at 
that the major portion of the gold is present in the pyrites, while some is 
undoubtedly free at and near the surface. 

A long cross-cut was driven in to strike this lode at a depth of about 
200 feet from the surface. 

In the cross-cut, three hard bands of homblende-olivine-dolerite were 
cut bearing iron pyrites alternating with granophyre varying from moder- 
ately hard to soft. The rocks appeared to be in beds from 8 to 20 inches 
thick, trending east 10 degs. south and dipping south 86 degs. to 58 degs. 
A few joints cut these beds striking north 22^ degs. west to north-west, and 
dipping south 54 degs. Others ran east and west to east 22^ degs. south, 
dipping north 51 degs. to 62 degs. 

• ** It is worthy of note that in this mine (Latham and Watson's quartz mine, on 
Hustler's Reef, Sandhurst) the gold is aggregated in cavities with the softer sulphides, 
such as galena, and is rather sparingly diffused in the laminae which enclose iron 
pyrites." — R. Brough Smyth, Gold Fields and JMineral I>ijftncU of Victoria.^ 1869, 
page 329 ; see also footnote on same page. Galena is often associated with free-gold 
in the New Morgan gold-mine of Wales. 



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244 0BGA.N08 DISTRICT, TOLIMA, U.S. COLOMBIA. 

According to recently published reports, highly contorted ground has 
been met with just where the lode was expected to be cut, consisting of 9 
feet of blue auriferous quartz and 15 feet of limestone-deposits {sic)^ the 
latter also carrying some gold. 

In the north-western portion of the mine, the rock has a brownish 
mottled appearance ; examined through a microscope it is seen to be 
granophyre spotted with chlorite (probably after biotite). In this section 
the veins bear very little gold. 

In the same mine, a pyritous quartz-vein coursing through chloritic- 
schist was proved for about 185 feet in length. It trended on an average 
east 84 degs. south to west 84 degs. north. The filling was 18 inches of 
white quartz, well charged with iron pyrites, but the average assay value 
was only about 10 dwts. of gold to the ton. 

On the opposite side of the river Chiquili, several veins are seen 
trending through clay-slate rocks, some of which have been worked to a 
certain extent. In the bottom of the Arroyo del Muerto, separating the 
La Reina from the La Union claims, two veins appear to form a junction, 
V-shaped in plan. The easternmost of these consists of 8 inches of quartz 
sprinkled with sulphides. In a level 80 feet above, both the quartz and 
the country are loose in texture. The quartz is white, and in one leader 
8 inches thick below, 7 inches in the middle, and 8 inches at the top of 
the level. The vein trends north-west and dips south ; outside the level, 
the vein is split up and disordered. Higher up the hiU eastward are 
two outcrops which appear to be continuations of the western branch of 
the same vein. The first and lower one is 9 inches thick of brown quartz 
dipping south 24 degs. ; the second and higher one of similar quartz 
6 inches wide and dips south 89 degs. A sample from these out-crops 
gave 9 dwts. of gold to the ton. 

The westernmost vein nins east 10 degs. south to west 10 degs. north, 
and dips south 50 degs. on an avenge. The vein is traceable along the 
slope of the hill for a length of 800 feet, corresponding to a height of 
1 60 feet vertical. At the top working, the vein consists of 6 inches of solid 
quartz dipping south 78 degs.; 50 feet below this point, the dip changes to 
south 47 degs., and the vein averages 10 inches. The bedding-planes 
trend a little north of east, and dip south 62 degs., so that the vein forms 
an acute angle with them. 25 feet farther down, the vein consists of white 
quartz sharply curved in a double-cleaved or jointed rock (Fig. 21, 
Plate X.). The average dip is south 30 degs. In the lowest working 
(100 feet below the first) the dip is south 51 degs., and the thickness is 
2 feet of white quartz strongly cleaved and jointed. Samples from the 



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0RGAK08 DISTRICT, TOLIMA, U.S. COLOMBIA. 245 

Borface-workings averaged 5 dwts. of gold to the ton. Old workings 
exist under this vein which were inaccessible at the time of the writer^s 
visit. 

A tunnel, 600 feet above the river Chiquili, and a little west of these 
workings, has cut two veins. The first was cut 60 feet from the mottth, 
it trends north 22J degs. west, and dips west about 46 degs. For some 
distance the lode was auriferous, consisting of 21 inches of white and 
comparatively tender quartz sprinkled with iron pyrites. Southward the 
lode takes a sharp turn east, and here the lode is much flatter, consisting 
of whitish quartz sprinkled with a little iron pyrites. The rock is bluish 
clay-slate. The vein averages 6 to 6 dwts. of gold to the ton ; northward 
it is soft and worthless. About 20 yards farther west another vein or 
branch runs north-east and south-west, and dips south 46 degs., consisting 
of one foot of white quartz of very favourable appearance sprinkled with 
iron pyrites. It averages 10 dwts. (extremes, 6 dwts. and 8| ounces) of 
gold to the ton. It must form a junction with the first vein to the south, 
and is said to have done so in one of the stopes above, where rich mineral 
was found. 

Near the eastern boundary of the La Virginia claim, a quartzose vein, 
1 6 inches thick, is seen crossing the Arroyo north 86 degs. west to south 
36 degs. east in clay-slate country. The vein has been proved super- 
ficially along the slope of the hill for a length of 360 feet, corresponding 
to a vertical height of 126 feet. At the top working, the vein is seen to 
be a red and yellow-stained dyke of felsite with a little gossan and quartz 
3 feet thick in hard clay-slate rock (Fig. 22, Plate X.). 30 feet below 
this, the vein courses north-west, and dips south 72 1 degs. in a simi- 
lar hard country. The vein-formation is 3^ feet thick, the auriferous 
quartz consisting of a single layer lying near the footwall (Fig. 23, 
Plate X.). Divisional planes are traceable here trending east and west, 
and dipping south 76 degs. 70 feet below the last working, the vein 
consists of only 2 inches of quartz spotted with iron pyrites. The beds 
of the country here run east 85 degs. south to west 36 degs. north, and 
dip to south 61 degs. An average sample of the whole vein gave only a 
few pennyweights of gold to the ton. The country here is clearly uncon- 
genial, and the vein is pinched below. 

At the California mine, an auriferous quartz- vein is traceable for about 
360 feet on the slope of a hill, corresponding to a vertical height of 160 
feet. The lode strikes east 20 degs. south to west 20 degs. north, and 
dips from north 68^ degs. to south 58 degs. At the top working, the 
vein is 6 feet wide, consisting of 2^ feet of hard quartzose gossan with 



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246 ORGANOB DISTRICT, TOLIMA, U.S. COLOMBIA. 

iron pyrites on the hanging side, the rest being gossany clay (Fig. 24, 
Plate X.). The pyritous quartz assayed 2 ounces 13 dwts. 8 grains of 
gold to the ton, while the gossany clay only yielded about ^ ounce. In 
the croppings below the vein is very thin, consisting of quartz, gossan, and 
iron pyrites from 2 to 9 inches thick, the assays varying from 1^ to 9 
dwts. In one place the quartz is white and non-mineralized. 

At El Dorado, about 126 feet above the stream, a vein crops out 
trending north 32| degs. west, and dipping south-west 68 degs. It 
consists of ribs of quartz separated by layers of rock, and with gossan 
on the footwall. Samples from here have yielded from 9 dwts. to upwards 
of 6 ounces of gold to the ton. About 200 feet above this, another vein 
crops out bearing east 11 degs. south to west 11 degs. north, and dip- 
ping south 42^ degs., from 12 to 18 inches thick of solid quartz sprinkled 
with iron pyrites. Assays from here gave only from 4 to 8 dwts. 

At Concepcion, a vein trending east 21^ degs. south and dipping south 
44 degs., is seen cropping out in a qvsbrado ; it consists of 20 inches of 
hard quartz, with iron pyrites and galena. The hanging-wall appears to 
be hard granophyre, and the footwall hard homblende-dolerite. A few 
feet above, the vein thins away to 9 inches, while about 18 feet higher up, 
it appears only as 2 inches of soft green clay charged with two iron pyrites. 

The prevalent direction of the veins in this district appears to be a 
few degrees from east and west with a southerly dip. Several veins trend 
in a north-westerly direction, dipping south-west. A north-easterly 
direction appears to be exceptional, as does also a northerly dip (Fig. 25, 
Plate X.). 

Leaving the segregated veins out of account, which usually follow the 
bedding-planes, no well-defined system of fissure-lodes has as yet been 
discovered in this district. 

The veins run in various directions, and individually many of them are 
very variable in strike. The beds of the country appear to vary consider- 
ably in strike also. At the Chorro workings, some of the beds appear to 
run north 85 degs. east and to dip south 48 degs., while others trend mostly 
a few degs. north of east and dip south 62 degs. ; at La Beyna, about 
10 miles farther south, some beds are seen coursing and dipping the same 
as the latter, but in the same mine other beds strike east 85 degs. south 
and dip south 51 degs. At Silencio, on the opposite side of the river, 
some beds appear to run east 10 degs. south and to dip south 86 degs. to 
58 degs. ; while at Socorro some beds trend north-west and dip south- 
west. The rocks are frequently so altered as to have their bedding-planes 



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ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 247 

obliterated — ^the complicatioii is increased when, as is often the case, the 
rocks exhibit divisional planes running in various directions. 

The fissure veins are evidently of later date than the schistose and 
eruptive rocks, as they pass indiscriminately through both. 

It is extremely probable that all the veins have been filled by lateral 
secretion, i.e., the mineral contents, including the precious metals, have 
come in from the adjacent rocks. Certain bands of the metamorphic rocks 
as well as of the eruptive dykes are strongly charged with iron pyrites, and 
this mineral may be looked upon as the main source of the gold in the 
veins. At and near the surface, the well-known decompositions have taken 
place, resulting in the production of earthy brown oxide of iron (gossan) 
and the setting free of the gold. 

The association of manganese with gold has frequently been noticed. 
In this district the gossany veins are often characterized by the presence 
of this ore, and, in certain instances, they are specially auriferous when 
crossing bands of oxide of iron, manganese, and clay. 

It should be noted that in some countries — ^Venezuela for example — 
manganese is looked upon as a sign of poverty.* 

In some gold veins the presence of galena is regarded as a fevourable 
indication. This appears to be the case in this district, although the 
galena itself carries little gold. 

Gossan containing visible gold is usually regarded as a favourable 
feature for the precious metal occurring in depth, but, speaking generally, 
this is certainly not the case in this district. The gossany veins die out 
rapidly in depth, while the quartz fissure- veins seldom carry gossan at the 
surface. 

Some of the quartz fissure-veins appear to widen while others seem to 
pinch out in depth — but the latter may only be a temporary thinning due 
to hard and uncongenial rock. 

Although the quartz fissure-veins sometimes follow the direction of 
the bedding-planes, they more frequently cut them at an acute angle, 
obliquely, or at right angles ; they sometimes, too, follow the lines of 
contact between the sedimentary and eruptive rocks, and sometimes follow 
the dykes for a certain length, as well as the divisional planes. 

Mr. John C. F. Randolphf says that no true fissure-veins have yet been 
discovered in Tolima, and they are all classed by him under the head of 
bedded-veins. His observations, however, do not appear to have been 

* Les Filons A' Or de la Ouyane Frangaue, L. F. Viala, 1886, page 36. 
t " Notes on the Republic of Colombia, S.A.," Trans. Aw, Inst, Min, Eng.^ vol. 
xviii., pages 205-213. 



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248 OBQANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 

extended bo far south as Organos. Even with regard to other diBtricts 
this is a sweeping assertion to make, and the writer believes it is not borne 
out by facts. 

Quartz appears to be the only true gangne in these veins, and the 
metalliferous species are extremely few in number, being confined abnost 
entirely to auriferous iron pyrites, auriferous and argentiferous galena, 
blende, the oxides of iron and manganese (secondary), and a mineral not 
yet determined. 

In the quartz fissure-veins the band of quartz, which is generally 
found on or near the hanging-wall, may be looked upon as the filling of 
the original fissure ; other bands frequently occur adjacent to or near this, 
filling subsidiary fissures, or are the result of replacement of the country- 
rock. 

The rock on either side of the original fissure is often decomposed and 
mineralized, and frequently exhibits joints or fissure-planes parallel 
thereto. These were probably produced contemporaneously, and those 
that limit the mineral contents may be regarded as the hanging and 
footwalls of the vein. 

The country within the lodes may be looked upon as altered or un- 
altered rock in situ; and the original fissures were probably, in the first 
instance, mere cracks in the country rock. 

In places there is evidence of strong local disturbance in the rocks, due 
probably to great lateral pressure, which has produced local movements of 
one bed over another, resulting sometimes even in fracture (Figs. 1 and 4, 
Plate IX.). 

Finally, the behaviour of the quartz fissure-veins may generally be 
said to be irregular, and its peculiarities are as follows : — 

1. The thickness varies considerably, and sometimes at short dis* 
tanccs, both horizontaUy and vertically, from a mere joint-plane to about 
6 feet, the latter being rarely exceeded. The average would appear to be 
about 2 feet. 

2. The dip also varies considerably, although its general direction is 
nearly always south or south-west, according as the vein runs in an 
east and west or north-westerly and south-easterly direction respectively. 
The dip is rarely northerly or easterly, and when so the lode is usually 
marked by poverty. 

3. The strike is still more variable, and although some of the veins 
appear to follow the law of average bearing,* others appear very capricious 
in this respect. 

* Moissenct, Parties riches desJUons. 



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f*isn»U 



voL.jr/*LAT£ m. 



IPS District/, if. S. Colombicv 




Digitized by VjOOQ IC 
Vol. Xm, Plate T 



Digitized by VjOOQ IC 

I 



L^ J 



J^dS^TK/^ 



roL. Y Plate H 



IPS District. U. S. Coloifthutyl 



Fia. 18. 



Fia. 19. 










rV 







200- FT. LEVEL. 






Kvi>'/ '■.r/^'^^^ 



o »5 
25-19 
SOUTH 







•^ 



REFERENCE. 

5/rift« and Z)ip of Veins 

Strike and Dip of Joints, ) 
Beds or Bedded Veins j ' 



Digitized 



byGooalp 

VoL.XLn.PLArnM. 



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DISCUSSION — OBOANOS DISTRICr, TOLIMA, U.S. OOLOMBU, 249 

4. The walls are sometimefi ill-defined, especially in the eruptive 
rocks. In Figs. 16 to 20 a fiiirly well-defined hanging- wall is observable, 
while the quartz leader, which we may regard as a f ootwall, is often flat 
and irregular. 

AuBiFBROUs Impregnations. 

In addition to the deposits described in the paper there is another class 
in the district whidi may be termed auriferous impregnations. They 
occur in highly kaolinized granophyre, and run as a rule very irregularly, 
and appear to possess no walls or joints. 

At the Silencio mine, a deposit of this class has been opened near the 
sur&x;e. It deemed to run roughly north-east to south-west, and to dip 
flatly to the south-east. The rock appeared to have been subjected to the 
action of thermal waters from which hydrated oxide of iron and native 
gold had crystallized out. The mineral bore a great resemblance to 
specimens from the famous Mount Morgan niine of Queensland, but 
unfortunately it was not found in any quantity. Specimens occur rich in 
visible gold, but the average does not probably run more than half an 
ounce to the ton. It is believed that most of the gold occurs in the 
mineral in a very highly divided condition. 

Veins crossing these gold-impregnated beds would probably be found 
to be highly enriched therein. 

The gold in the Organos district contains a good proportion of silver, 
and is only about 650 fine. 



The President asked whether the mines were worked to any great 
extent, what was the quantity of gold produced, the number of workmen, 
etc. ? 

Mr. E. Halse replied that a large quantity of gold was not produced 
at present in the district described ; the value might perhaps be put down 
roughly at from £10,000 to £15,000 sterling per annum. The mines 
were being extended, and new veins were being opened out, so that in 
future the district might become a much more important one than it was 
at present. 

Mr. W. Cochrane asked whether the district was likely to become 
competitive with other gold-bearing districts of other parts of the world ? 

Mr. Halse said at .present it could not be considered as an important 
district, but he could not say what it might become with inrther develop- 
ment. 



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250 DISCUSSION — ORGANOS DISTRICT, TOLIMA, U.S. COLOMBIA. 

OORRESPONDENCE. 

Mr. David Burns wrote that the Organos mining-field seemed cal- 
culated to intensify the mystery that surrounded the origin of veins, 
rather than to afiPord material for a solution of the problem. The features 
recorded are pretty much what obtain when veins occur in extremely 
metamorphic rocks, save that the veins appeared to be of a specially weak 
and fragmentary character, but probably more extended operations and 
deeper working would show a greater continuity than now appears 
probable. It is abundantly clear from this paper and from many other 
observations, that the contents of the bedded veins were to a great extent 
determined by the surface of the ground, and that consequently they were 
filled when the surface-configuration was approximately what it is now. 
This is proved by the contents of the veins altering in depth, and in most 
cases disappearing altogether. The conversion of pyrites into gossan 
is easily explained by atmospheric influences, but the displacement of 
auriferous quartz by flucan, as greater depth is attained, admits of no 
such solution. Neither does the segregation idea help us at all. Let 
us suppose that a limited amount of intensely heated and highly fluid 
mineral substances was escaping from the interior along contact-planes 
as being the planes of least resistance. So long as these substances 
remained perfectly fluid, they would allow the rift between the rocks to 
close behind them, but when they began to cool down and became viscous, 
they would begin to clog up the vent, those with the lowest melting-point 
getting nearest the surface. This assumption explained why such veins 
so frequently disappear in depth and present a distinct succession of 
mineral in depth. It was inconceivable that pyrites and quartz could 
traverse the planes of bedding of the country-rock by any other agency 
than galvanic action. If galvanic action had caused the segregation, 
would not the metals of the veins be found in continuous ribs, and the 
metals in the metallic form instead of as ores ? Metalliferous veins are 
generally found intersecting dykes and cross-courses and are thus proved 
to be of later age, and they may be of a much later period than has 
hithei'to been suspected. Mr. Halse says " the rock oil either side of the 
original fissure is often decomposed and mineralized, and frequently 
exhibits joints or fissure-planes parallel thereto," but this feature was well 
explained by the theory of the eruption of vein-stuff from below, and not 
at all by the author's theory of secretion. Much of the quartz and clay in 
the veins may be the country rock completely metamorphosed by the hot 
erupted vein-matter, whereas the rocks just referred to have been less 
altered. The fissure-veins that appeared to widen in depth are probably 



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DI8CUS8I0N— -ORGAKOS DISTRICT, TOLIMA, U.S. COLOMBIA. 251 

stronger or have had more cover than those that narrow downwards ; and 
those that widen in depth will ultimately narrow if followed far enough ; 
their fluids having been able to expend most of their energies before 
reaching the surfeoe, while those that are widest at the outcrop have not. 
Mr. E. Halse wrote that Mr. David Burns appeared to think that 
veins were filled by mineral substances ascending them in a more or less 
molten condition. This seems an extraordinary view to take, and one to 
which the writer believes the present structure of veins lends no support 
whatever. On the contrary, all the evidence seems to show that the 
mineral substances were deposited from chemical solution (presumably 
from heated waters, but not necessarily so in all cases). The writer has 
advanced no new theory in his paper, but he has taken the most generally 
accepted one, that of lateral secretion — first outlined by Delius in 1770, 
and in recent years propounded with much scientific evidence by Fridolin 
Sandbei^er,* and largely suppoited by such keen observers as Emmons, 
Curtis, Becker, and others— as explaining best the mode of filling of at 
least the superficial veins of the district described. No single theory will 
explain all the phenomena connected with mineral veins, nor can it be 
expected to do so, for the structure is often extremely complicated, owing 
probably to the veins having undergone many physical and chemical 
changes since the first filling. 



The President proposed a vote of thanks to the writer of the paper. 
Mr. M. Walton Brown seconded the vote of thanks, which was 
cordially adopted. 



The Rev. G. M. Capell read the following paper on the "Manometric 
Eflficiency of Fans" :— 

♦ Untersuchitngen iiber Srz(fatige, 1882, 1885. 



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252 MAKOMETRIC EFFICIENCY OF FANS. 



MANOMETRIO EPPICIENCY OP FANS. 



By THE Rev. O. M. CAPBLL. 



It is now about ten years sinoe the term ^^manometric efficiency" 
was brought prominently forward by Mr. Daniel Murgue, and the term is 
one not generally understood. It refers simply to the relation of the 
water-gauge to the speed of the blade-tips of a fan, and has no necessary 
relation to the useful effect of a fan. 

Mr. 6. Herbst, in speaking of fan tests, specially remarks that high 
manometric effect does not necessarily imply high useful effect. In fact 
the evidence of tests by Pan Commissions prove the exact contrary, as 
will be shown later on. When we consider that the water-gauge and 
volume represent two sides of a balance, of which the water-gauge 
represents the longer arm, it seems natural to expect, if the water- 
gauge be reduced, that the volume of air will be increased, and with it the 
useful effects at a given speed. With high manometric effect, the fan is 
not working on a full flow of air, and consequently is wasting power in 
creating the high vacuum implied in a maximum water-gauge with a 
minimum quantity of air passing. 

In the trials of Guibal fans by the Committee of the North of England 
Institute of Mining and Mechanical Engineers,* the 50 feet Ouibal fan 
at St. Hilda colliery showed a useful effect of 42*09 per cent., while the 
manometric effect was 64*1 per cent. ; the 40 feet Guibal fan at Pemberton 
colliery showed a useful effect of 62-96 per cent., with a manometric 
effect of 52*1 per cent. ; the Guibal fan at Cannock Wood colliery showed 
a useful effect of 47"95 per cent., with a manometric effect of 66 per 
cent.; and the Waddle fan at Celynen colliery, with a useful effect of 50*5 
per cent., gave a manometric effect of 45'7 per cent. 

Another consideration comes in next, that is the position of the end 
of the water-gauge tube. In all the early Guibal fans the water-gauge 
tube was placed either in the centre of the inlet over the bearing or in 
the fan case. Now this makes a considerable difference in the calculation 
of the manometric effect. If another water-gauge were placed on the 

• Traru, N. B, IjuL, vol. autx., page 273. 



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MANOMBTBIO BPPIOIKNCY OP PANS. 263 

drift, 20 feet from the fan inlet, another and a lower reading would be 
shown. There is an instructive example in the trials of the 80 feet Guibal 
fan at Staveley colliery by Mr. Robert Howe,* at 56 revolutions of the fan 
the water-gauge in the inlet was 2*52 inches, with a manometric effect of 
73 per cent. ; but the water-gauge in the drift was 2*10 inches, with a 
manometric effect of 60*3 per cent. There is a difference of about 13 per 
cent, in the manometric effect, obtained by changing the water-gauge from 
a position at the fan-inlet to the drift-door, which was close to the fan- 
inlet. At a distance of 20 feet, the manometric effect would have been 
much less. 

In recent trials of fans by a private commission in Belgium, there ifl 
an interesting series of diagrams showing the position of fan-inlets and 
the water-gauges at various points. At the Rieu-du-Cceur colliery, a Rateau 
fan has been erected, and this fan is said to show a manometric effect of 
80*2 per cent., with a useful effect of from 35 to 47 per cent. The 
position of the water-gauge tube was peculiar. The conical adjutage, 
joining the fan to the drift, is of small diameter, not above 4J feet, and 
the water-gauge tube is placed in it. With 59,488 cubic feet of air passing, 
the velocity would be 4,210 feet per minute in the tube, and, by Dr. 
Hutton's rule, the water-gauge due to that velocity would be 1'70 inches, 
representing a very large deduction from the 4*29 inches shown, had the 
gauge been taken on the door of the large drift, from which the fan was 
drawing. Yet a comparison is made of the manometric effect of that fan, 
with its water-gauge tube in the position described, with that of a Capell 
fan at the Prosper colliery, with the water-gauge tube placed about 90 
feet from the double inlets of the fan, in a drift of 55 square feet area, 
the water-gauge showing 6*10 inches. 

If manometric effects are to be of any use in comparisons, the con- 
ditions of taking them should be settled, as they become misleading when 
made under wholly different conditions. In the report of the Belgian 
Commission, only the Guibal fans appear to have been tested under 
similar manometric conditions. 

Another point is worthy of notice, that a very small fan pa^ising a 
large volume of air has to raise that air to a high velocity ; and velocity 
means work done, and it is fair to measure the work done, remembering that 
the static water-gauge (t.e., the water-gauge taken out of the air-current in 
the fan-drift) is the water-gauge which should be effective for the ventila- 
tion of a mine. That water-gauge can always be ascertained by taking a 
reading on the outer door of the fan-driil, the inner door being open. If 

• Drans, Chesterfield InsU^ vol. i., page 46. 



Digitized by VjOOQ IC 



254 MANOMBTRIC EPPIOIBNCY OF FANS. 

all water-gauges were taken thus, the nsefnl effects would become less, as 
at present calculated, but the real efFective work of fans would become 
clearer. 

The writer has found that the highest useful effects in fans of the 
double centrifugal type is obtained between 47 per cent, and 54 per cent, 
of manometric effect. This agrees with the results of the Committee of 
the North of England Institute on Guibal fans, and brings the useful 
effects of Guibal fans down to the level of fans placed on Belgian mines 
by Mr. Guibal. The position of the water-gauge tube in fan tests deter- 
mines not only the manometric ef&ciency, but the mechanical efi&ciency ; 
and the reduction of the mechanical eificiency becomes a serious matter 
in a case where, with one fan, the water-gauge tube is placed, say, 60 feet 
away from the inlet of the fan, while with the other fan the water-gauge 
tube is placed in or close to the inlet. It follows, that in such calculations, 
some fixed distance from the inlet should be settled for the water-gauge 
tube end, so as to avoid conclusions which are misleading and inaccurate. 

Another point of discussion is whether the water-gauge effect on the 
mine ventilation is the same with a double-acting as with a single-acting 
centrifugal fan. Experiments with two fans acting in succession, t.g., 
one fan discharging into the inlet of another, show that the effect is 
not the same as with only one fan acting on the mine at a given speed. 
The writer believes fully in the difference, and this is a point which 
would at once raise a question as to the real worth of exceptionally high 
manometric effects. 

The manometric rule of Mr. Murgue shows a theoretical gauge double 
of that given by Mr. Guibal h = u^ -i- g; whOe Mr. Guibal used 

A curious point comes out in examining these water-gauges and 
manometric effects. If a fan gives 80 per cent, of manometric effect, 
then the speed of the air flowing into the vacuum, formed by the 
revolving blade-tips, is greater than the velocity of the actual circum- 
ference of the fan. Take the case of a fan 9*2 feet in diameter, 
giving 80 per cent, of manometric effect at 228 revolutions and 4*29 
inches of water-gauge. The velocity due to a depression of 4*29 inches, 
calculated by the following formula: v = >/A x 66 1, is 136"7 feet 
per second or 8,202 feet per minute, while the periphery speed of the 
fan is only 6,573 feet per minute. It is extremely probable, if a lower 
velocity of blade-tip speed can raise a depression producing a higher speed 
of air, that there are some deeper problems underlying the action of 
centrifugal fans than have been thought of, and the whole theory of fan 
action may have to be revised. 



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DISCUSSION — MANOMKTRIC EFFIOIBNOY OP PANS. 255 

The object of the writer of this paper is to shoV that high manometric 
effect does not necessarily imply high useful effect, and also to point out 
the need of some accepted rules for testing fans, to avoid unsafe results 
in manometric effect and useful effect in comparing fans, where the 
water-gauge has been placed under entirely different conditions. 

Further trials were made on May 23rd last, of the Guibal and Capell 
fans at the Maries collieries, in the north of France. The results were : — 

Fan, diameter (feet) 

Reyolutions per minute, engine 

Do. do., fan 

Water-gange, near inlet (inches) 

Do. in main drift in a recess, 

and common to both fans (inches) ... 

Volume of air per minute (cubic feet) 

The difference of 0*45 inch between the inlet and static water-gauge 
in the case of the Guibal fan is very large, while the difference between 
the inlet and static water-gauge in the case of the Capell fan is only 0*75 
inch. The efficiency of the Guibal fen is very low, being only 39 per 
cent, of the inlet water-gauge. 



QnlbalFan. 


GapeUFan. 


23 


12i 


76 


68 


75 


306 


1-40 


910 


0-96 


8-35 


72,559 


203,328 



The Presidbnt said he thought it would be desirable in discussing 
this paper, to take at the same time the discussion on the following 
papers : — "Observations on Fans of Different Types Working on the same 
Upcast Shaft," by the Rev. 6. M. Capell;* and "Experiments upon a 
Waddle Fan and a Capell Fan Working on the same Mine at Equal 
Periphery Speeds at Teversal Colliery," by Mr. J. C. B. Hendy.f 

Mr. W. Cochrane said he would like Mr. Capell to make his meaning 
perfectly clear as regards the manometric efficiency. In the paper it was 
said to refer "simply to the relation of the water-gauge to the speed of the 
blade-tips of the fan, and had no necessary relation to the useful effect of 
the fan." Did this mean that the manometric efficiency was the water- 
gauge (irrespective of where it was taken) compared with the theoretical 
water-gauge ? If so, it was simply the relation of the indicated water- 
gauge (the water-gauge itself, measured and seen) to the theoretical 
water-gauge ; and he wanted to know whether the latter was based upon 
^ = tt* -r ^ or A = w* -f- 2^ ? 

Mr. A. L. Stbavenson referred to the same paragraph as to the 
manometric efficiency in which Mr. Capell said " it refers simply to the 

♦ Trans, Fed, Ifut,^ vol. iv., page 208. f ^^id., page 474. 



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256 DISCUSSION — MANOMBTRia KFFICIBNCY OF FANS. 

relation of the water-gange to the speed of the blade-tips of a fan, and 
has no necessary relation to the useful effect of a fan/' If they took 
any ventilator and found that some part of its work was performed 
more eflSciently than in any other fan, it followed that the useful effect, 
all things being equal, would also be higher. Mr. Thomas Bell (H,M. 
Inspector of Mines) and Mr. Cooke were the first to make observations 
upon the pseudo water-gauge, and they noted that the water-gauge in the 
case of the Guibal fan had in all cases exceeded %? -r- 2^, which, he 
thought, was accounted for by the action of the 6vas^e chimney. Un- 
doubtedly the 6vas^e chimney entirely altered the conditions under which 
the speed of the blade-tips governed the theoretical water-gauge. The 
general law of the manometric eflSciency of fans was now so well 
established that it could not be resisted ; in fact, Mr. CapeU had recog- 
nized the advantage of the 6vas6e chimney, and now used it in the con- 
straction of his fan. The only question now in dispute was the position 
of the water-gauge. He thought the proper position was at such a 
distance from the fan that it was not affected by the speed of the fan, 
say, for instance, at the bottom of the pit. 

Prof. J. H. Mebivalb said he understood Mr. Capell to say that it 
should be taken as near to the fan as possible, and where the air was 
practically at rest. The best position would be in the fan-chamber. 

Mr. Capell said with regard to the question of the higher manometric 
efficiency necessarily implying a higher useful effect, his own experience 
was diametrically opposed to such a conclusion, and in the recent experi- 
ments at Maries colliery, carefully conducted by capable engineers, they 
arrived at a result which was a startling surprise. 

Mr. W. CocHEANB asked the meaning of " double centrifugal type of 
mine-ventUator," and whether it applied to others than the Capell fan ? 
Would he call the Guibal or Waddle fans " double centrifugal " ? 

Mr. Capell said they were single-centrifugal fans, but the Pelzer and 
Eateau fans were of the double centrifugal type. 

Mr. W. Cochrane referred to Mr. Capell's statement that "some 
fixed distance from the inlet should be settled for the water-gauge tube- 
end, so as to avoid conclusions which are misleading and inaccurate.'* If 
he (Mr. Cochrane) remembered rightly, Mr. Capell argued in a previous 
discussion* that the principle of the Capell and similar fans was such 
that they carried back (for the same velocity of blade-tip) a water-gauge 
very much farther into the mine than any other kind of fan ; therefore, 
if at the surface, a distance of 20 feet or so away, were settled as a 
• Tran9, Fed, Irut*, vol. Iv., page 204. 



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DISCUSSION — MANOMBTRIO BPFICIBNOY OP FANS. 257 

suitable position for the water-gauge, an advantage would be claimed in 
all cases for Capell fans and those of similar type ; that is, that they 
•would be able to indicate a higher water-gauge at a distance of 20 feet 
from the fan than any other fan. The Guibal fan at Maries, which 
produced 72,559 cubic feet at 0*95 inch water-gaage, in the fan drift 
would produce 203,000 cubic feet in the same mine at 7'486 ioches of 
water-guage. It seemed to him that the Capell fan indicated a higher 
water-guage to circulate this volume than the Guibal fan, but such 
higher water-guage was not required, and ought to yield, if utilized, a 
much larger volume of air than 203,000 cubic feet per minute. 

Mr. Capell asked what would have been the water-gauge of the 
Guibal fan when circulating 203,000 cubic feet per minute ? 

Mr. Cochrane— In the proportion of 72* : 208* = 0*95 : 7-486 
inches. 

Mr. A. L. Stbavenson said that if they took the experiment on the 
Guibal fan and used the formula u^ -f- 2^, they got an efficiency exceed- 
ing 100 per cent., which was impossible. It was necessary to recognize 
the effect of the 6vas^ chimney, and the square of the speed of the 
periphery should be divided by g and not 2^. 

Mr. T. H. M. Stratton said he would leave the scientific part of the 
discussion to Mr. Cochrane, but he thought Mr. Capell was under a 
mistake if he assumed that tbe manometric efficiency had anything to do 
with the useful effect. If they had a fan perfectly suitable to the size 
of the mine, running at a certain speed, and with its outlets and intakes 
adapted to that mine, they obtained a high useful effect, but they could 
not predict the proper size of fan to put up unless they knew the area of 
the orifice of the mine. 

Mr. W. C. Blackett said he was in considerable doubt as to what 
Mr. Capell meant to convey by his paper, more especially as to water- 
gauges. From his use of the term " static " as applied to a water-gauge 
in one part of his remarks, and in another to some mysterious influence 
" thrown back from the fan," he (Mr. Blackett) was not able to say 
whether the difference was due to this mysterious influence "thrown 
back," or to the dynamical effects of the air-currents. As Mr. Capell 
used the word "static '^ he thought he had in mind the dynamic effects 
of air-currents passing the open mouth of a tube connected with the 
water-gauge ; this was one thing, but this influence " thrown back " 
from the fan was another, and he (Mr. Blackett) could not quite under- 
stand whether in speaking of having to be careful against the static gauge 
they were to be careful to get out of this mysterious influence or to get 

17 



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268 DISCUSSION — ^MANOMETUIO EFFICIENCY OF FANS. 

out of the influence of the dynamic effects of air-currents. In the latter 
case, he did not see how putting the water-gauge on the second of the 
separation-doors got over the difficulty, as in that case they simply, 
altered the shape and length of what might be called equivalent to the 
tube of the water-gauge. He understood Prof. Merivale to say that it 
was not necessary for the air in connexion with the water-gauge to be 
perfectly at rest, but Mr. Capell considered that it should be at rest. But 
he (Mr. Blackett) took it that in all water-gauges connected by the 
fan-drift with the tube, the air in the tube was at rest, and merely altering 
the shape of the end of the tube and expanding it into a passage at 
right angles — or any other angle — to the fan-drift did not provide them 
with air not in motion, and he thought in fact the widening out of the 
tube and placing the widened mouth against the air-current might prevent 
them getting much water-gauge at all. About fifteen years ago he made 
some experiments upon a Schiele fan with the special object of getting to 
know the influence of the position and direction of the pipe upon the 
readings of the water-gauge, in relation to the air -current and the orifice 
of the fan, and he was able to get from O'SO inch with the pipe-mouth 
facing the current to over 2 inches where the pipe was reversed, and 
there was at the same time about 0'50 inch registered on the drift doors. 
Although Mr. Cochrane might be in doubt as to which theoretical water- 
gauge ought to be accepted, there was considerably more doubt as to how 
they were to measure the practical water-gauge, and he had not heard 
anyone yet give any rule as to taking a water-gauge that would be 
equally applicable to any fan-drift. He thought they would always have 
differences in their observations — one gentleman on one side doubting 
the veracity of another gentleman on the other side as to the results 
produced from their respective fans — unless they could hit upon some 
contrivance, be it simple or otherwise, for getting a water-gauge free 
from all influence of air in motion, and especially free from that 
mysterious influence which Mr. Capell said was capable of being " thrown 
back " from the fan. 

Mr. A. L. Steavenson said he thought he could elucidate the matter. 
The water-gauge decreased as they got farther away from the fan, until 
they reached a point at which it became practically constant. If a fan 
created a vacuum giving more air than the fan could contain, they would 
get a pseudo water-gauge. A large fan of 40 or 50 feet in diameter 
produced no pseudo water-gauge ; but a small fan running on a large 
mine produced great pseudo water-gauge, because the vacuum produced 
more air out of the mine than the fan could swallow. 



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DISCUSSION— MANOMBTRIC EFFICIENCY OF FANS. 269 

Mr. W. C. Blackbtt rejoined that Mr. Steavenson's statement 
proved that he was more influenced by the mysterious influence of the 
fan '^ throwing back " than by the dynamical effects of the air-current, 
and he (Mr. Blackett) was still in as much doubt as ever as to which 
should have the more importance attached to it. 

Mr. Oapell said that in order to avoid all dynamic influence of the 
current on the water-gauge, he had tried the experiment of using a sharp 
pointed tube, which he drove into a ball of worsted where nothing could 
get at it. For practical use a tube of perforated zinc placed on the end 
of the water-gauge tube, and covered with cotton-wool and then wrapped 
over with several layers of flannel was equally efficient. 

Mr. T. H. M. Stratton said that roughly speaking, they might put 
the manometric efficiency of the Guibal fan at 0*64 and the Waddle^ 
Schiele, and Oapell at 0-46. 

Mr. Ferrier said he did not think the manometric efficiency affected 
the mechanical efficiency, for the highest manometric efficiency was 
obtained when the mine was shut off, when the mechanical efficiency 
was nil. He did not see how the dynamic effects could very readily be 
produced in a substance of such small density as air ; in hydraulic experi- 
ments they had a very great effect on the pressure at a particular point along 
the pipe through which the water was passing, but he thought this was 
very different to what the effect would be on a substance of such small' 
density as air. The energy must be very small in consequence of the 
small weight of air, and it was difficult to see how the dynamic effect 
could produce an appreciable effect on the water-gauge. They might 
suppose that the pressure would form rapidly as it went along the drift to 
the end of the fan, but it would be difficult to find at what part it would 
be best to place the water-gauge ; it would depend largely on the passage 
through which the air was moving ; the larger the area through which 
the air was passing the less the pressure required to drive it through. 

Mr. Capell said if they took a glass tube 3 feet long and blew across 
its end they would get a water-gauge of 14 or 15 inches, and this was 
exactly what happened in a tube placed in a very high velocity of air- 
current ; the air whistling past its end raised the observed water-gauge to 
a higher point than the static water-gauge would be. 

Mr. J. 0. B. Hendy said that he agreed with Mr. Capell's remarks as 
to the dynamic results observed in the drift. The dynamic water-gauge 
would be due to the velocity or impulse of the air passing the orifice of the 
tube ; that is to say, if the orifice of the water-gauge tube was uncovered 
in one instance and covered in another, there would probably be a 



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260 DISCUSSION — ^MANOMBTRIC EFFICIENCY OF FANS. 

difference in the water-gauge, and that difference would be due to the 
dynamic effect. He understood Mr. Oapell to say, in the paper he had 
just read, that a fan might have a very high manometric eflSciency and at 
the same time a low mechanical efficiency, and that one machine might be 
a better ventilator with a high manometric efficiency and a low mechanical 
efficiency, than another macliine which gave a comparatively low mano- 
metric efficiency and high mechanical efficiency. This raised the question 
as to whether they were to judge the fan and engine as a whole^ or one 
machine, or to separate the two and simply judge the fan from its mano- 
metric efficiency and the volume of air it produced. No doubt the fan 
might suffer in the comparison if driven by a badly constructed or 
inefficient engine, but on the other hand they ought to know which fan 
required the most engine power, and he thought that experiments ought 
to be made so as to obtain such data as would enable them to make a fair 
all-round comparison. In most of the cases quoted by Mr. Oapell where 
a Guibal or other lai^e fan had been replaced by a Capell fan, it should 
not be forgotten that the former had been replaced by a Oapell fan designed 
to give a much larger volume of air than the old fan was capable of 
exhausting, and (in the comparisons he makes) he gives the calculated 
water-gauge required for the old fan against the actual water-gauge 
obtained with the new fan. He did not think it was right to compare the 
calculated water-gauge from a fan designed to produce say 50,000 cubic 
feet per minute with the actual water-gauge given by a new fan designed 
to produce 120,000 or 150,000 cubic feet per minute. What they wanted 
was a comparison between fens each designed for the same duty and 
working under the same conditions, and so far as he could remember Mr. 
Oapell had not quoted any such instance. 

Mr. M. Walton Beown said that Mr. Guibal (many years ago) 
showed that in either a cased or open-running fan a force equal to that 
induced by the velocity of the circumference was wasted, and he further 
proved that the ideal centrifugal fan should be provided with an expand- 
ing-chimney or similar apparatus which would utilize the work remaining 
in the air on its issue from the fan. If that adjunct was of infinite 
dimensions, Mr. Guibal showed that the water-gauge would be doubled, 
and it had not been found difficult in practice to make a centrifugal fan, 
provided with an expanding-chimney, produce 80 to 88 per cent, of the 
theoretical yield calculated by the formula w* -h g. In other words, Mr. 
Guibal accepted «* -f- 2^ as the value of the theoretical water-gauge 
produced by either cased or open-running centrifugal fans ; and in the 
case of the ideal centrifugal fan provided with sliding-shutter and expand- 
ing-chimney, he proved that this value of the theoretical water-gauge was 



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DISCUSSION — ^HANOMBTBIO BFFICIBNCY OP PANS. 



261 



doubled, or 2 {ifl -f- 2^) = w« ^ ^, which agrees with Mr. Murgue's 
fonnula. H« (Mr. Brown) could not accept Mr. Capell'g view that the 
manometric efficiency of any type of fan could be considered as having a 
constant fixed value, irrespective of the conditions of the mine. The 
following table records the work of the old single open-running inlet fan 
at Birch Coppice colliery,* together with certain calculated results deduced 



OboerratioDa. 



11 

hi 



162 
120 
137 
137 
152 






OnbioFt. 
70,280 
60,000 
73,000 
73,000 

118,498 



Ins. 

MO 

0-70 

0-90 

0-86 

0-45 



Oaloolated Besolta at 106*1 
BeTolntions per Minute. 



Sq.Ft 
24-75 
26*53 
28-47 
29-30 
65-35 






Oubio Ft. 
49,057 
53,050 
56,535 
66,535 
82,714 



Indhei. 
0-636 
0-547 
0-539 
0-509 
0-219 



Sonaraiof 
V<diime. 



2,406,699,249 
2,814,302,500 
3,198,206,225 
3,198,206,225 
6,841,605,796 



Water-gauce. 



Ins. 
0-577 
0-644 
0-613 
0-513 
0-216 



8 I 
1^ 



Ins. 
-0-041 

0-003 

0-C 
-0-004 

0-003 



0-269 
0-275 
0-271 
0-256 
0110 



therefrom. If a diagram be made with the squares of the volumes (v*) as 
abscissae, and the observed water-gauges (K) as ordinates, a straight ILue 
could be drawn approximately through the five points, having for its 
equation h = 0-773 inch — 0-000,000,000,081,5 v*. The calculated 
water-gauges (h') are obtained from this formula, and the difference 
ih — h') shows the apparent errors. These differences are slight, except 
in the case of No. 1 experiment, and may be set down to errors of obser- 
vation. Taking the initial water-gauge (0-773 inch) and the observed 
water-gauge (A), it will be seen that the manometric efficiency is not 
constant for the Birch Coppice fan, and that it varies from 0-462 at the 
initial water-gauge, to 0-110 in No. 5 experiment. Mr. Capell, in a 
previous paper,! alleges that there is "a different water-gauge in the 
Guibal fan when passing the same volume of air as the small Capell fan," 
and "the lower gauge for a given work in air shows itself wherever the 
Capell fan has replaced a Guibal fan." The statement is not borne out by 
the experiments recorded in Mr. Capell's paper, as the comparison is made 
by calculation of the results of the Guibal fan at a low peripheral speed 
with those of the Capell fan at a much higher peripheral speed, and not by 
direct comparisons of the water-gauges of both fans when actually passing 
the same large volume of air. Thus at Prosper I collieries, the Guibal fan 
producing a volume of 59,340 cubic feet is compared by calculation with 

♦ Trans. South Staffs, Inst. Min. Ung,, vol. xi., page 74. 
t TraTu. Fed, Inst,, vol. iv., page 203. 



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262 



DISCUSSION — ^MANOMETRIC EFFICIENCY OF FANS. 



the Oapell fan volume of 127,574 cubic feet per minute ; and at Maries, 
the Guibal fan exhausting 72,559 cubic feet is compared with a Capell fan 
producing 208,328 cubic feet per minute. The manifest unfairness of 
such comparison of the results obtained by one fan with those produced 
by another fan running at a much higher peripheral speed is clearly 
evidenced by a comparison of Nos. 1 and 5 experiments upon the Capell 
(12^ feet double-inlet) fan at Silverhill colliery,* as follows :— 

Revolutions of fan per minute 

Volume of air per minute (cubic feet) ... 
Water-gauge in fan-drift (inches) 

Taking No. 1 experiment of 110,920 cubic feet under 1*40 inches of water- 
gauge, the Capell fan would n^quire not less than 4*50 inches of water-gauge 
instead of 4*10 inches, actually observed in No. 5 experiment. These 
experiments show that a fan (in certain cases) yields better results than 
a fan running at a lower speed, and that such an unfavourable comparison 
at a low speed occurs equally in the case of the Capell fan as in any other 
fan. He (Mr. Brown) had considered the experiments made upon the 
Capell and Waddle fans at Teversal collieries, and he thought that the 
following experiments were worthy of comparison : — 



No. 1 
Experiiuent. 
123 


No. 5 
Experiment 
215 


110,920 
1-40 


.. 199,660 
4-10 



Description 
of Fan. 


No. of 
Experi- 
ment. 


Dia- 
meter. 


No. of 
ReTolu- 


Volume 

of Air 

perBfinute. 


Water- 
gau«e. 


Keferenoe. 


Cai)en ... 

Waddle ... 
Capell ... 
Waddle ... 
CapeU ... 
WadcUe ... 


A. 
A. 

B, 


Feet. 
16 

30 
16 
30 
16 
30 


113 

52 
131 

65 
135 

70 


OuWoFt. 
88,046 

87,729 
101,747 
103,381 
116,494 
114,309 


Inches. 
1-40 

1-00 
1-90 
1-95 
2-20 
215 


Trans, Fed. Inst,— 

vol. iv., page 476. 

voLiv., „ 477. 

vol. iv., „ 476. 

vol. ii., „ 543. 

vol. iv., „ 477. 

vol. ii., „ 643. 



The volumes in the above table, when reduced to a peripheral speed of fan 
of 6,000 cubic feet per minute, show the following comparative results : — 



No. of 


CapeUFan. 


Waddle Fto. 


A 
B 
C 


Cubic Feet. 
93,000 
92,700 

103,000 


OuWoFeet. 
107,400 
101,200 
103,900 


Mean ... 


96,200 


104,200 



• Trans, Fed, Inst., vol. ii., page 549. 



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DISCUSSION — MANOMKTRIC EFFICIENCY OF FANS. 263 

These experiments also prove that the Waddle fan produced practically 
the same volnme of air at a much less water-gauge than the Capell fan at 
Teversal collieries. 

Mr. Capell said that in considering the output of fans, the cubic 
contents of the fan and the output per revolution should not be forgotten. 
The Oapell fan at Maries collieries had more than double the output per 
revolution of the Guibal fan. Working under the very high water-gauge 
required at Maries collieries, he calculated that 208,000 cubic feet would 
be exhausted at 810 revolutions per minute under 9 inches of water- 
gauge, and, as a matter of fact, at 306 revolutions the quantity of air 
was 208,328 cubic feet per minute under 9*10 inches of water-gauge, which 
was very near to the difficult guarantee which he had given. The rule 
for calculating the theoretical water-gauge referred to in his paper was 
Mr. Murgue's rule, A = m* -j- g. On the Continent, this rule is now 
universally acknowledged, and the manometric efficiency is measured by 
its results. He (Mr. Capell) did not advocate taking the water-gauge 
close to the fen, as it was then influenced by local effects. Where 
practicable, it should be taken at a distance of 20 feet, and in a recess. 
He was questioned with regard to higher manometric efficiency implying 
higher useful effect; in the December (1892) tests of the Maries fan,* 
the manometric effect with a less volume of air than was obtained in May 
last was 0'647, with a mechanical efficiency of 0*578. A new form of 
shutter had been placed in the fan, and the chimney water-gauge had been 
decreased by its use. The result showed a corresponding decrease in the 
manometric effect, as in the last trials it was only 0*5109, but the useful 
effect rose to 0*591. The rise being about the same as the decrease in the 
manometric efficiency. The 12 feet single inlet fan, to which Mr. Brown 
refers, was the second Capell fan used on a colliery, and was an open fan 
of a type now discarded, and its results were not constant. The fan was 
an experimental one, from which useful deductions for future work were 
obtained. He (Mr. Capell) strongly protested against there being any 
unfairness towards a fan of 40 feet diameter and 10 feet wide at Prosper 
colliery being compared with a fan 12 feet 6 inches in diameter and 6 
feet wide, or a fan 23 feet in diameter at Maries colliery being compared 
with another 12 feet 6 inches in diameter. The comparison is fair, as the 
large fens working on low water-gauges get the advantage of natural 
ventilation, which passes away when producing water-gauges of 6 inches 
to 11 inches. The unfairness, if any, seemed to be all the other way. 
Two independent observers have made tests of the Teversal fans, Mr. 
• Trans, Fed, Inst., vol. iv., page 215. 



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264 DISCUSSION — ^MANOMBTRIO BFPICIBNCY OP PANS. 

"W. Piggford and Mr. Maurice DeacoD. They have both proved the 
abnormal resistance required to get the air to the Capell fan inlet. Both 
of them have found that at the same water-gauge taken on the same 
water-gauge pipe for both fans on the drift, and in spite of the resistance 
between drift and inlet, the Capell fan has the advantage both in volume 
and useful effect. The water-gauge to get the air to the inlet from the 
drift is work done needlessly, and with a better arrangement the Capell 
fan would use that water-gauge in getting large volumes of air. As so 
much discussion had been raised over the trials of the fans at Teversal 
collieries, he hoped it might be possible to test the fans under nearly the 
same conditions by placing a temporary arrangement in the drift (if per- 
mission could kindly be given) ; but it would be quite impossible to get 
exactly the same conditions owing to the peculiar position of the Capell 
&n which is laid across the drift. Mr. Cochrane in his calculation had 
taken the static water-gauge as the water-gauge of the Ouibal fan, instead 
of the inlet water-gauge, and had left out the effects of an important 
factor, the natural ventilation of the mine, which would come into action 
very strongly at the low water-gauge of 1*40 inches, in reducing the pro- 
portion between the inlet water-gauge and static water-gauge, but would 
not influence the high water-gauges. As a matter of fact there was a 
natural ventilation of about 16,000 cubic feet per minute at Maries 
colliery, and those who have studied the recent paper of Mr. T. A. 
Southern* will at once recognize how unsafe it is merely to rely on the 
squaring of the air-volume to get the water-gauge required for a large 
increase of the ventilation, unless natural ventilation is allowed for and a 
corresponding proportion of water-gauge added to the direct calculation 
from the squares of the volumes. In the Maries experiments, the 23 feet 
Quibal fan gave a useful effect of 89 per cent, on the water-gauge 
measured in the inlet of the fan, and 27*9 per cent, on the static water- 
gauge taken in a deep recess in the wall of the main-drift, which was 140 
square feet in area. Hence, naturally, the static water-gauge useful 
mechanical effect of the &n had not been noticed in previous trials of this 
Guibal fan. The Guibal fan produced in round figures 72,000 cubic feet 
per minute at a water-gauge of 1*40 inches in the inlet to the fan ; the 
static water-gauge for 203,000 cubic feet by calculation is obtained thus : 
As 72,000* : 203,000* = 1*40 : 11-109 inches. The horse-power in the 
air is found to be : 203,000 x 1*40 x 5*20 H- 88,000 = 355-5 horse- 
power ; and at 89 per cent of useful effect, the Guibal fan would have 
required 355-5 x 100 -=- 89 = 911 horse-power to have produced 208,000 
* Trans. Fed. InsL, vol. iv., page 460. 



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DISCUSSION— HYDROGEN-OIL SAFETY-LAMP. 265 

cubic feet of air per minute. The Capell fan results previously recorded 
show 291*5 horse-power in the air by water-gauge near inlet, and of 
267*5 in the air by the static water-gauge ; the engine being indicated at 
495*0 horse-power; the useful effects being 59*1 per cent, by the water- 
gauge taken near inlet, and 64 per cent, by the static water-gauge. The 
contrast thus worked out is very clear, and the efficiency of the Guibal 
fan, worked out both on the inlet water-gauge and the static water- 
gauge, is also evident. The manometric efficiency of the Guibal fan at 75 
revolutions, taking the inlet water-gauge, is 88*5 per cent., and taking 
the static water-gauge it is 26*12 per cent. The Capell fan, at 806 
revolutions, gives on the water-gauge near the inlet 51*09 per cent, of 
manometric efficiency, and on the static water-gauge gives 46*8 per cent, 
of manometric efficiency. 

The President said the discussion would now be adjourned, but in 
the meantime he thought their hearty thanks were due to Mr. Capell for 
endeavouring to enlighten them on these difficult problems. 

The proposal was cordially adopted. 

Mr. Capell responded to the vote of thanks. 



DISCUSSION UPON PROP. P. CLOWES' PAPER ON "A PORT- 
ABLE SAFETY-LAMP, WITH ORDINARY OIL ILLUMINAT- 
ING FLAME, AND STANDARD HYDROGEN-FLAME, FOR 
ACCURATE AND DELICATE GAS-TESTING."* 

In the absence of Prof. Clowes, Mr. Palmer exhibited and explained 
the use of the hydrogen-oil safety-lamp. 

The President asked if the lamp was in actual use ? 

Mr. Palmer replied that it had been in actual use for some months 
at the West Riding collieries. 

Mr. A. L. Steavenson suggested that if the appliance would give 
equal results in ordinary coal-gas they might see some experiments with 
it now. 

Mr. Palmer said this was not practicable, owing to the absence of a 
test-chamber. 

Mr. M. Walton Brown emphasized the remarks he made when the 
lamp was shown at Derby,! and said that he would like information on 

* Tram, Fed, Irut,, vol. iv., page 441. f Ibid.j page 456. 



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266 DISCUSSION — ^HYDROGBN-OIL SAFETY-LAMP. 

the following points : — {a) Was there any danger, when filling the hand 
cylinder with hydrogen from the large cylinder, of an explosive mixture 
being formed ? If the valve of the hand cylinder was left open it might 
be filled with air, which would become explosive if mixed with hydrogen 
from the large cylinder, after the pressure had been reduced by repeated 
chargings of the hand cylinder. (J) The risk of the hydrogen being 
turned into the lamp at full pressure, and burning a hole in the gauze or 
cracking the glass, {c) The risk of the passage of flame through the 
pipe used for the introduction of the hydrogen gas from the hand 
cylinder. Prof. Clowes stated that* "It should be noted that the 
hydrogen-fiame can be set to its standard height in the presence of the 
gas in measuring the fiame-caps, and that the test can therefore be at 
once made in the air to be examined without previously placing the lamp 
in gas-free air." He thought that if, say, 1 per cent, of gas was mixed 
with the air, the bulk of the hydrogen-flame would be enlarged accord- 
ingly, and it seemed to him impossible to adjust the hydrogen-flame to its 
standard height in such a mixture of gas and air. He thought the use of 
the lamp might be greatly simplified, if the gas could be produced chemi- 
cally by an attachment to the lamp. He had used the hydrogen produced 
in a Dobereiner lamp as a test-flame for fire-damp, and suggested that 
Prof. Clowes might with advantage adopt a similar system. 

Mr.'PALMBB, referring to the question of air being left in the cylinder, 
said that no harm would result, and two or three chargings would entirely 
remove it. He thought the lamp would be safe if the hydrogen were 
suddenly turned on at full pressure ; the flame would simply shoot to the 
top of the lamp, but he did not think it would burn a hole through the 
gauze before being reduced. 

Prof. Mbeivale observed that this point could be easily settled by 
experiments. 

Mr. Palmer, continuing, said the hydrogen-flame was always of the 
same height, and there was a clear line of demarcation between the 
hydrogen-flame and the gas-cap, which were perfectly distinct. 

Correspondence. 

Dr. P. P. Bedson wrote regretting his absence during the discussion 
on the hydrogen-flame lamp, for he would have wished to express his 
admiration of the ingenuity displayed in the construction of the lamp. 
At the same time, he (Dr. Bedson) must confess to a feeling of disappoint- 

• Trans. Fed, Inst., vol. iv., page 45 J. 



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DISCUSSION— HYDHOGBN-OIL SAFETY-LAMP. 267 

ment at the indications yielded in low percentage mixtures of fire-damp 
and air ; in fact, in those ranges where an indication is most needed. The 
difference in the length of flame in J per cent, mixture and ^ per cent, 
mixture is practically useless as a means of gauging the amount of gas 
present, and does not compare at all favourably with the results of 
experiments with the Pieler lamp, made by the Austrian Fire-damp 
Oommission, or of those conducted by Dr. Brookmann for the Prussian 
Fire-damp Commission. Dr. Brookmann states the difference in height 
of flame to be 2 centimetres (0*79 inch), which is about twenty times the 
difference in height of the hydrogen-flame. The Austrian Commission 
found a similar difference in the height of the flame, when experimenting 
with mixtures of Rossitzer ga?, Segen Oottis mine, corresponding to 4 
and i per cent, of marsh gas ; whilst with other natural gases — ^the same 
difference in amount of marsh gas — ^the flames differed in height by 
1 centimetre (0*89 inch), which is still ten times greater than the differ- 
ence observed with the hydrogen-flame. These facts show the hydrogen- 
lamp cannot for such low percentages compare for delicacy with the Pieler 
lamp as an indicator of fire-damp. He (Dr. Bedson) would like to have 
asked Prof. Clowes how, when the lamp has once given an indication of 
gas, it is possible to set it without again bringing the lamp into an 
atmosphere free from gas. He (Dr. Bedson) understood that one of the 
disadvantages under which the Pieler lamp labours arises from the 
volatility of the alcohol; but the construction of the hydrogen-lamp 
requires the presence of a volatile oil, which is a factor of danger, just as 
alcohol is with the Pieler lamp. It would appear desirable that experi- 
ments with all such lamps should be made not only with marsh gas, 
prepared in the laboratory, but with gas collected in the mine, for^ as 
shown in the experiments of the Austrian Commission, considerable 
differences may be observed, and it would be useful to know how these 
fire-damp indicators behave in different samples of fire-damp. 

Dr. Clowes wrote that he fully endorsed the replies given by Mr. 
Palmer. In practice the small cylinder was found to be freed sufficiently 
from air by charging it once with hydrogen, and allowing this to blow 
off. Those who had used the lamp for some time underground, made no 
complaint of any difficulty in r^ulating the supply of hydrogen so as to 
avoid the production of an unduly large flame. The passage of flame 
outwards from the interior of the lamp through the hydrogen tube had 
been proved by many experiments to be impossible. Great importance 
is attached to the fact that in measuring the cap-heights, the hydrogen 
flame was always set to its standard height in air containing the known 



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268 DISCUSSION — HTDROGBN-OIL SAFETY-LAMP. 

percentage of gas. It is therefore unnecessary to remove the lamp to 
air free from gas in order to adjnst the standard hydrogen-flame. 
Unfortunately the chemical generation of hydrogen gas from materials 
within the lamp had been long ago proved to be an impossibility. The 
flame of the gas chemically produced could not be regulated, and the 
metallic parts of the lamp were constantly corroded by the chemicals used. 
An experimental lamp, with which the attempt was made, never left the 
chemical laboratory. On the other hand, the present lamp, in which the 
hydrogen was prepared, and then applied in a compressed state, had, 
after lengthy trial worked very satisfactorily. He (Dr. Clowes) regretted 
that Dr. Bedson had not had an opportunity of seeing the hydrogen-oil 
lamp exposed to low percentages of gas in the test-chamber and in the 
pit. If this opportunity had been afforded (and Dr. Clowes was now 
prepared to offer it in any convenient way or time), no doubt would have 
been expressed as to the indications furnished by the lamp in } and even 
in i per cent, of gas. It would be seen that the cap-heights for these 
low percentages of gas (^ and J) were practically equal, but that the 
caps were distinguishable even by a novice without the slightest hesita- 
tion. The i^ per cent, cap is hazy, pale, and indefinite in outline, but 
perfectly visible, and the ^ per cent, cap is much less pale, and is com- 
paratively well-defined. The caps are not distinguishable by dififerenoe 
in height, but a glance serves to distinguish them by their appearance. 
As regards the distinction of the different percentages, from ^ to 6, 
no difficulty has presented itself either in the laboratory tests in the test- 
chamber or underground, in the hands of officials. It is true that the 
caps are all smaller than those shown by the Pieler lamp, but they are 
quite large enough to give easily appreciable differences to the unaided 
eye, and when viewed against the special gauge in this lamp they can be 
noted with certainty by any one. The Pieler caps are unnecessarily 
large, and are very seriously hindred from being properly seen by the fact 
that they are viewed through metallic gauze^ and with a most unsuitable 
gauze background ; whereas in the hydrogen-oil lamp the caps are viewed 
through transparent glass against a dead-black and most suitable back- 
ground. The standard hydrogen lamp could be set to its standard height 
with absolute certainty in any part of the pit, and did not require to be 
taken into fresh air for adjustment. This had been secured by always 
Betting the flame to its standard height in the presence of the gas in the 
test-chambers, and then reading the cap-height which was registered on 
the gauge and the scale-card for use in the pit. For low percentages of 
gas this was, however, unimportant, since the hydrogen-flame, when set 



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DISCUSSION — ^HTDROGBN-OIL SAFETY-LAMP. 269 

in air free from gas, did not appreciably increase in size until more than 
3 per cent, of gas was present in the air. For detecting percentages of 
gas above 8, the use of the reduced oil-flame (also set in the presence of 
the gas) was recommended. Dr. Bedson was in error in stating that a 
volatile oil was used in the hydrogen-oil lamp. The oil burnt was 
a mixture of colza with water-white paraflSn ; the latter was not volatile, 
and was considered to be a perfectly safe oil in any form of lamp. The 
paraffin was introduced to prevent charring and crusting of the wick, and 
thus to improve the burning and the ease of reduction of the flame by 
drawing down the wick, it also improved the light of the flame. As 
regards the testing of the lamp in mine-gas as well as in artificially 
prepared marsh-gas, it should be remembered that in the preparation of 
a scale for the lamp, known percentages of marsh-gas must be employed, 
and this is most readily and certainly secured by mixing methane with 
air in known proportions. Carbonic acid is the only gas likely to affect 
the cap, and special experiments in the test-chamber have shown that 
even 5 per cent, of carbonic acid does not affect the cap. The precau- 
tion, however, has been taken of making tests side by side in the main 
return airway with the hydrogen-oil lamp, the Pieler lamp, -and the 
Liveing indicator, with the result that, in percentages of gas ranging 
from J to 2, the indications of the three instruments were absolutely 
identical. Dr. Clowes wished further to state that in comparative tests 
in low percentages of gas made with the hydrogen lamp and with the 
Pieler lamp, the caps were easily read in the hydrogen lamp, but they 
were not readable in the Pieler lamp furnished by an English firm. 
This defect was partly due to the luminosity of the large alcohol flame, 
but largely to the interference caused by the metallic gauze. The brass 
gauze partly acted by impeding the passage of the light of the faint caps, 
but mainly by its reflecting power. Some improvement was noticed 
when the gauze was blackened. But only on the removal of the bonnet 
and gauze were the tall caps satisfectorily seen in then* full dimensions. 



The President proposed a vote of thanks to Mr. Palmer for attend- 
ing to explain the use of the testing-lamp. He hoped something 



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270 DISCUSSION — HYDBOOEN-OIL 8AFETY-LAMP. 

practicable would before long result from the various instruments which 
were brought forward from time to time, and this lamp certainly seemed 
to tend towards the object thej wished. 

The vote of thanks was unanimously adopted. 



The following paper was taken as read :— " The Choice of Coarse and 
Fine-crushing Machinery and Processes of Ore Treatment," by Mr. A. 
G. Charleton. 



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PKOCESSBS OF ORB TREATMENT. 271 



THE CHOICE OF COARSE AND FINE-CRUSHING MACHIN- 
EEY AND PROCESSES OP ORE TREATMENT/ 



By a. G. CHARLETON. 



Part III.— Silver. 

Wet and Dry Pan-amal0amation and Lixiviation. 

Pan-amalgamation, as applied to silver ores, is always preceded by 
stamping the ore in a battery. If conducted wet, the pulp is collected 
in tanks, from which it is shovelled into the pans (an arrangement which 
might, the writer thinks, be improved upon), or else, if arranged on the 
Boss system (much in fashion lately owing to the saving in labour and 
other advantages claimed for it) the pulp is run straight through a series 
of pans without any intermediate settling. If conducted dry, the ore is 
taken direct from the cooling-floor of the roasting furnace (which forms 
an essential part of the plant), and is charged into the pans afterwards. 

Pan-amalgamation is most extensively used in the Western States of 
America for the extraction of silver from its ores, and with such excep- 
tions as have been or will be alluded to, is, the writer thinks, likely to 
retain its position for some time to come. 

It broadly divides itself, as will be presently seen, into : — 

1. The Washoe process, in which the ores go direct from the tanks 
to the pans wet, the amalgamation being generally assisted by 
the use of chemicals, chiefly salt and bluestone. 
3. The Reese River process, in which the ore must be first dried : (a) 
on a drying-floor heated by waste-steam or furnace gas ; or (5) 
in revolving drying-cylinders or shelf -kilns, which are steadily 
coming more into fashion. Roasting (usually with salt, which 
is mixed in the battery, or between it and the furnace) follows 
drying, and the ore is ground in pans in the same way as in 
the wet process. 
3. The continuous Boss process. 

♦ Trans, Fed, Inst,, vol. iv., pages 233 and 851. 



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272 pbocesseb of ore treatment. 

The Washoe Process. 

In an ordinaiy wet-crashing silver mill, the ore is brought in cars to 
the top of the mill-building, where it is dumped over the top of the inclined 
grizzley or screen on to the crusher-floor. All the small pieces pass through 
the grizzley into the ore-bins below. The coarse rock is shovelled into 
the jaws of the rock-breaker, which are on a level with the crusher-floor. 
The ore crushed to walnut size in passing through the rock-breakers falls 
into the ore-bins, and thence goes to the automatic feeders (behind the 
stamps), passing through inclined shoots controlled by gates. The auto- 
matic feeders being kept full, ensure a uniform supply of stone being fed 
to the stamps as fast as needed. 

The finely stamped ore, known technically as pulp, suspended in water, 
flows into large settling-tanks, where the excess of water is drawn ofif, 
whUe the thick pulp remaining is shovelled in regular charges into a row 
of amalgamating-pans, in which it is ground for several hours, first with 
salt, blucstone, and other chemicals, and afterwards amalgamated with 
mercury, with the mullers raised. The contents of the pans are run into 
large settlers (when the previous operation is finished) placed below, and 
in front of the pans, in which the pulp is thinned by additions of water 
and gentle agitation, and all the quicksilver with the precious metals in 
the form of amalgam, settles to the bottom. The pulp is gradually drawn 
off from the settlers (through holes fitted with plugs at different levels in 
the side) and flows to waste. The amalgam is strained from the excess 
of quicksilver, Retorted to drive off what remains, and the resulting gold 
and silver cake is melted into bars. The gold and silver contained in 
the sulphides, which will not yield to the above treatment, is sometimes 
caught by concentrators (Prue or Embrey) which receive the waste pulp- 
tailings from the settlers. A clean-up pan generally forms part of the 
plant. 

The old method usually employed in silver-milling was to crush coarse 
in the battery and grind fine in the pan, but as this involves greater 
power, greater wear of castings, greater loss of mercury, and not always 
better results, the system of crushing fine in the battery (keeping the 
shoes barely off the dies) has lately come into practice. By this means 
more gold and silver will sometimes be extracted, since ore will naturally 
break where there is most mineral, and the fine comminution in the battery 
will generally disengage most of it, the consequence being, that as quick- 
silver has a preference for gold and silver, it will amalgamate with them, 
rather than take up base metals (which render it inactive), which it is 
forced to do by excessive grinding. 



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PHOOBSSES OF OBB TREATMENT. 273 

The modern amalgamating-pan is a growth from the old arrastra, and 
though its construction is quite simple it presents a variety of forms. The 
pan holds from 1 and 1 J to 2 tons of pulp, and generally revolves at about 
60 revolutions per minute; the gearing underneath is open and plain, 
the muUer is raised by a left-hand screw qu top, the hand-wheels of which 
should be large (the jam-wheel being no smaller than the screw-wheel), as 
it frequently requires a greater application of muscle than the latter, and 
when the machinery is in fast motion it is inconvenient to adjust a small 
wheel under a large one. The most important feature of the pan is the 
pulp-current, which often receives but little attention, and though simple 
in principle is not always understood, and its neglect may cause serious loss. 

These currents must be uniform and regular to ensure uniform work, 
and strong enough at the bottom of the pan to carry the quicksilver. 
The motion of the muller makes a current by throwing the pulp to the 
outside as it advances, which then rolls up at the side and falls over 
towards the centre, and down through the central opening, in and under 
the muller, to be thrown outwards again from the bottom. This so far 
cannot be improved upon, but the wings are needed, to give the pan 
capacity (by preventing the pulp from running too high up at the side), to 
accomplish which, they should have the shape of an inverted ploughshare. 

Having naturally a good current above the muller, we have only to 
work in unison with that underneath it, which will depend on the design 
of the muller and setting of the dies. 

The pans vary in diameter from 4 feet to 5 feet 6 inches, and 
have generally a cast-iron flat bottom with wooden sides. They 
ordinarily hold 1,200 to 1,300 lbs. of ore, and three is the usual 
number allowed per battery of five stamps, but sometimes two will 
be found suiBcient. Each pair of pans requires one settler. In some 
districts copper plates are introduced into the pan, and much of the 
amalgam is found attaching to these, but the more usual system is to 
employ settlers entirely for the collection of the quicksilver and amalgam, 
after the pans are discharged. While the pulp is being worked in the 
pans, which usually takes 6 to 8 hours, steam is introduced to heat the mass 
and promote the chemical reactions ; sometimes live steam is introduced 
direct from the boilers into the charge, but more commonly the pan is 
furnished with a false steam-bottom, and heated with the exhaust from 
the engine. The bottom of the pan is protected by cast-iron dies, and 
the muller is furnished with adjustable shoes, so that the wearing surfaces 
are renewable if it be necessary to grind the ore. The shoes and dies can 
be brought together when grinding by means of the hand-wheel, and 

VOL. V.-4WS-W. ^® 



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274 PBOGESSES OF 0KB TREATMENT. 

screws on top of the spindle, or the mailer can be raised above the dies 
for circulation and mixing only. 

The screw on the settler-driver, should, unlike the pans, be right- 
handed, for besides being more convenient in case of a belt slipping, the 
power applied to turn the screw, helps the muUer to revolve. A settler 
should never be allowed to foul by an accumulation of heavy matter at 
the bottom, it is a positive preventive of good work. It is, however, 
easier to advocate this than to do it. An apparently natural remedy, viz., 
a liberal use of water, tends rather to aggravate the difficulty ; there is a 
point in the thinning when the quicksilver will be precipitated, but the 
heavy sand be held in suspension. 

If, after the charge is run out (which should leave about 8 inches of 
pulp in the settler), a pan is drawn and no water is added for half an 
hour, the warm charge will gather and carry the heavy sand ; now enough 
water only is added to reduce it to the appearance of still some thickness, 
and this is all the water that is used in the charge. A horn spoon will 
show its success in advance of results. 

Settlers are generally made with wooden sides 8 feet in diameter 
inside the staves, an automatic syphon-tap being provided for the dis- 
charge of the quicksilver and amalgam. Around the bottom a groove is 
cut, starting from nothing on one side, and gradually deepening to the 
syphon-tap opposite, in which all the quicksilver is carried to the outlet. 

The muller-plate attached to the driver-arms, is shod with wooden 
plough-shoes, which are sometimes, however, attached direct to the arms 
themselves. The speed of the settler is generally about 16 revolutions per 
minute. Concentrators for a silver-mill must of necessity be simple and 
capacious. Good agitators (shovelled out often) are profitable. In some 
cases sand sluices are very effective, consisting of a broad sluice 20 to 24 
inches wide, in which at intervals of 8 or 10 feet vertical strips are fixed 
at the side to hold movable riffles. The riffles (battens of wood) are laid 
in, and the sands run over them for a time (say one or two hours), when 
another coarse of riffles | inch thick or less is laid on the first ones. 

This is repeated until the sluice is full, when it is shovelled out, 
meantime allowing the sands to run through a duplicate sluice, at the 
side. Such sluices should have a grade of about 8^ inches per rod to 
keep them under control, as by starting with a thin riffle at the bottom 
a strong current may be produced, whereas the introduction of a thidc 
riffle will give a deadened current. 

These sluices are an advantage where blankets are profitable, and if 
followed by blankets relieve the latter from much coarse, heavy material. 



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PROCESSES OF ORB TREATMENT. 276 

A blanket sluice should have a grade of about 8 inches in 7 feet. The 
stock of mercury in a silver-mill should be large to begin with. In a 
dry-crushing silver-mUl the loss is usually from J to | lb. per ton of ore. 
A 10 stamp mill usually requires from 200 to 250 lbs. of mercury per 
month to make up the loss. The quantity needed in stock depends on the 
richness of the ore, but is approximately 1,500 lbs. in the pans, 1,500 lbs. 
in the settlers and in circulation, and 1,500 lbs. locked up in amalgam, 
so that a total stock of 2 to 3 tons would be necessary for starting with. 

KoASTiNQ MiLLmG. — Thb Kbesb ErvER Process. 

After passing the rock-breaker, the ore is dried by passing through a 
continuous revolving-drier or shelf dry- kiln beneath the breaker, the dried 
ore being taken by car or else run through shoots (lined with sheet iron 
and regulated by gates) to the automatic feeders, if the fall admits of it. 
The stamps are fed while the ore is still hot, the pulverized product 
being conveyed to the elevator, by which it is carried to the iron storage- 
hopper of the roasting-fumace. In the furnace the ore, with the addition 
of common salt, is desulphurized and chloridized, thus preparing it for the 
pans and settlers. After roasting, the ore is spread on a cooling-floor, and 
is taken in cars as required to the pans. Amalgamation follows on the 
same plan as in wet crushing-mills. In old type mills it was formerly the 
practice to employ drying-floors of boiler or cast-iron, from which the ore 
was shovelled to the stamps, in place of the more modem arrangement of 
an automatic revolving-drier. 

The Boss Process. 

This process marks a new epoch in the milling of silver ores in the 
United States and in Mexico, as it presents claims to superiority in 
many respects over the old system of pan-amalgamation. The large 
saving in labour and fuel, increased cleanliness, reduced wear and tear, and 
other features that will be mentioned later on, combine to make it a 
favourite with mill-men. It does away with the large pulp settling-tanks 
and consequent shovelling and handling of the pulp, which is a serious 
item of cost in ordinary wet treatment ; it saves the erection of the tanks 
and the space they occupy ; and no slum-pump or agitators are required. 

The buildings and cost of erection for a continuous mill are less 
expensive than for an ordinary one, as they require less grading and 
retaining-walls and cover less area. The ore passes through the grizzley 
and crusher in the usual manner and down the automatic feeders to the 
stamps. The pulp flows from the battery through pipes to the special 



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276 PROCESSES OP ORB TREATMENT. 

grinding-pans (the product of ten stamps passing through two in succes- 
sion). The pulp is then conveyed by pipes to the first amalgamating-pan, 
and flows continuously through the lines of pans and settlers. The tail- 
ings are run off and led over concentrators. A special feature of this 
process is that the pulp in the amalgamating-pans is always kept thin, 
instead of being about the consistency of thick cream, as usual in the 
ordinary pan process. The quicksilver is charged to the pans by means 
of pipes from the distributing-tank, and the amalgam flows direct to the 
strainer. The chemicals are supplied to the pans by two chemical-feeders. 
Steam syphons are provided for cleaning out the pans, and for conveying 
the pulp past any pan when it is necessary to cut it out of the series for 
repairs. The main-line shafting runs directly under the pans and settlers, 
each of which is driven from it by a friction-clutch. This arrangement 
of separate clutches for each pan and settler is very convenient, as any 
number or any one pan and settler can be stopped in case of accident for 
cleaning out, without having to stop the whole line. 

All the water from the batteries must pass through the pans, so that 
all the slimes are treated ; there m less loss of mercury and a true sample of 
the tailings can be obtained, a matter of much greater difficulty with the 
old method. Heating by exhaust steam is stated to be one of its 
economical features, obviating any strain upon the pan, which is heated 
indirectly through the hollow steam-bottom. Where changes were made 
from live to exhaust steam in some mills it is said to have saved as much 
as £2 10s. Od. to £3 2s. 6d. per day for cord wood.* By using special 
grinding-pans, the ore can be crushed through a coarser screen in the 
battery, and the finer grinding can be afterwards accomplished in the 
pans, thus obtaining increased capacity. 

Though it does not pretend to cope with rebellious ores which ar« 
unsuited to such treatment, the Boss process is without doubt a great 
improvement over ordinary pan-amalgamation in tanks. If the latter 
process be employed, the tanks are filled in succession ; the pulp being 
conveyed to them through a launder, by means of which the supply is cut 
off as each vat becomes full. Arrangements should be made to settle as 
much of the mineral as possible by allowing the water to circulate through 
the empty tanks before passing to the slum-pit outside, the escape or 
tailings water being turned into each tank after emptying it of sand. 
Each tank in turn thus receives the water after passing through the other 
tanks, and becomes the final one of the series. In some mills a certain 
number of tanks are kept employed in settling the sands, while the 

* Messrs. Fraser-Chalmers, Catalog^ie. No. 4, page 82. 



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PEOCESSES OP ORB TREATMENT. 277 

remainder are used up for the slimes ; in others the capacity of the vats 
is large enough to settle the sands and slimes together. Before charging 
the pulp into the pans it is usually shovelled into heaps on the platform 
in front of the pans, which is slightly inclined towards the tanks to drain 
the water back into them. In the pan-treatment a proper consistency of 
the pulp, a proper degree of heat, and clean quicksilver, are matters of the 
chiefest importance. 

While charging the pan the muller for grinding is kept revolving and 
lowered, water having been previously run in so as to fill the pan to 
within 12 to 18 inches of the edge, and heated with steam. Some mill-men 
favour direct heating with live steam, others by means of a jacket or false 
bottom. The chaise must be heated nearly to boiling-point by turning 
on steam again during the grinding. At the commencement of the 
grinding the pulp is thin, but after a couple of hours it will acquire the 
proper consistency for receiving the quicksilver, which becomes diffused 
(by the heat and grinding) in small globules through the mass. The pulp 
should be thick enough to cling to a wooden paddle dipped in to test it, 
showing particles of mercury evenly disseminated through it, so that the 
charge will carry the quicksilver in suspension. The salt (say about 
10 lbs.) is added as soon as the pan is charged, and 2 lbs. of sulphate of 
copper (or whatever proportion is used), half an hour later. After the 
pulp is heated to about 180 degs. Fahr. steam is cut off, and the muller 
should be lowered gradually during the progress of grinding. When 
finished (after about 2 hours), some 200 lbs. of mercury are added to a 
1,200 lbs. charge of pulp. The grinding is then sometimes continued for 
another half-hour or an hour, when the muller is raised and the pan run 
with the muller up, for 3 hours more. There is, however, less chance of 
flowering if the bulk of the mercury is not added until the grinding is 
entirely finished. A quarter of an hour before drawing the charge, suffi- 
cient water is added to fill up the pan, thinning the pulp thoroughly, so 
that it will flow readily out of the pan, and cooling it. 

The work should be so arranged as to charge and discharge a pan 
every 6 hours, which gives it a capacity of about 2^ tons. The pans should 
be discharged in succession, not all simultaneously ; that is to say, as soon 
as one or two pans have been discharged and refilled, after a certain 
interval (depending on the number of pans in the mill) the next pan or two 
should have completed their 6 hours' work, and be ready to undergo the 
same process. 

When discharged, a stream of water should be directed into the pans, 



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278 PEOCBSSBS OF ORE TREATMENT. 

to rinae them out thoroughly. Everything thus flows to the settlers, and 
through the partial dilution of the pulp, the quicksilver settles to the 
bottom, and is collected in the syphon. During the discharge of the pans 
the settler arms are kept revolving, and after a short interval a spray of 
water is turned on, and allowed to run till the settler is full. It is then 
turned off and the muller is allowed to revolve for an hour. This allows 
the quicksilver to collect and settle. An abundant stream of cold water 
is then let in and the settler is allowed to discharge through the different 
plug-holes, commencing with the top one, the operation being timed so 
that the bottom hole is reached just in time to receive the next charge. 
Once a week or of tener the settlers should be cleaned out, and the coarse 
sand and sulphides accumulating in the bottom are re-worked in the 
pans. Generally two settlers discharge into one agitator, and a constant 
stream of water should run into them. They collect some coarse sand 
containing a little quicksilver, amalgam, sulphides, and a quantity of iron 
which is worked-up in the clean-up pan. The floors should be kept as 
clean and free from dirt as possible. All drains should lead into the 
agitators, and unless the weather is too cold the quicksilver floor should 
be sluiced down with a hose daily. 

Betorting Amalgam. 

The retorts for retorting silver bullion are generally cylindrical or 
square with the comers rounded off, and containing shelves for several iron 
dishes. They should be heated to a bright cherry-red he:\t before com- 
mencing the retorting, otherwise it is difficult to drive off the last traces 
of quicksilver. A serious loss is entailed by a retort bursting, not an 
uncommon occurrence even with the greatest care. They must therefore 
not be fired too strongly, and must be strongly made and well braced. 
The mercury fumes are condensed by condensers acting on the Liebig 
principle, the quicksilver being caught in a bucket of water, into which 
the end of the pipe from the retort dips ; care being taken that the water 
is not able to run up into the retort as it cools by the end of the pipe being 
too deep under water. After the retorting is finished it is advisable to 
leave the retorts to stand for several hours before withdrawing the bullion. 

For cleaning quicksQver from impurities, which become mechanically 
mixed with it, the quicksilver strainer invented by Mr. H. H. Oakes is 
recommended by Mr. Eissler and is described by him in detail* 

• Metallurgy of Silver ^ page 159. 



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PROCESSES OF ORE TREATMENT. 



279 



General Bemares, Ores, etc. 

The ores of silver which, can be successfully treated by the Washoe 
process are those in which the metal occurs in a condition which will be 
acted on by quicksilver, assisted by heat, agitation, and certain chemicals 
(chiefly salt and sulphate of copper), which produce a certain quantity of 
sub-chloride of copper, through the secondary action of the metallic iron 
present. The chloride and sub-chloride of copper (both of which arc 
liable to be formed), tend to reduce any sulphides of silver present, by 
exercising a chloridizing influence upon them, and at the same time 
decompose the sulphides of lead and zinc. The sulphate of copper, 
moreover, enhances the amalgamating energy of the mercury by tending 
to expel the lead, and by causing the formation of a small quantity of 
copper amalgam. 

A list of the chief ores and minerals containing silver would comprise 
the following : — 



Name. 








when Pure, 


Nanmannite 


Ag,Se 


73-2 


Bnkairite 


Ca,Se + Ag,8e 


43-1 


Hessite 


Ag,Te 


62-8 


Petzite 


(AuAg),Te 


41-8 


Sylvanite 


(AuAg)Te, 


10 to 15 


Argentite (silyer-glance) 


Ag,S 


87-1 


Stromeyerite 


Ag^ + Cu,S 


531 


Stembergite 


AgFe^. 


34-2 


Miargyrite 


Ag^ + SbA 


86-7 


Pyrargyrite 


3Ag^ + Sb,S, 


59-8 


ProuBtite 


3Ag.S + A8,S. 


65-4 


Stephanite 


5Ag,S + Sb,8, 


68-6 


Brogniardite 


PbS + Ag^S + Sb,S, 


261 


Polybasite 


9(Ag,Cu)S + (SbA8),S, 


68-0 


Tetrahedrite (Pahlerz)... 


(CuAg),8 + (SbA8Bi),8, + (Fe ZnHg)S 


variable. 


Xanthoconite 


(3Ag.S,A8,S.) + 2(3Ag,8,A8,8^... 


6400 


Fire btende 


AgSb8 


62-3 


Freieslebenite 


Pb.Ag.SbA 


23-8 


Cerargyrite (horn-gilver) 


AgCl 


75-33 


Bromyrite 


AgBr 


57-40 


Embolite 


Ag(ClBr) 


61 to 71 


lodyrite 


Agl 


46 


Native silver 


... 


100-00 


Arquerite (native amal- 






gam) 


AgHg 


34-8 


Electram (native alloy of 






gold and silver) 





27 to 32-7 



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280 PROCESSES OF ORE TREATMElfT 

Minerals, etc., often containing silver in small quantity : — 

Galena PbS 

Blende ZnS 

Pyrite FeS, 

Chalcopyrite CuFeS, 

Erubescite CugPeS, 

Mispickel FeS, + FeAa, 

Altaite PbTe 

Clausthalite PbSe 

Nagyagite (Pb AuAg) (Te, 8), 

Chivialite (Cu,Pb) S + iBi,S, 

Dufrenoyslte PbS + Ag,S, 

Bnargite 8Cu,S + A&,S, 

Cupel bottoms, droBS litharge sweepings, etc. 
Slags, etc. 

The presence of sulphides of iron, copper, lead, zinc, and antimony, 
interferes with the success of the amalgamation process in several ways. 
They foul the amalgam and check the reactions of the chemicals on the 
free-milling minerals, and carry off in their refractory combinations a 
portion of the silver which the latter contain. It often happens that while 
the upper decomposed surface-ores of a vein are free-milling, as depth is 
attained (beyond the decomposing action of the air and surface waters) 
they change in character, through sulphides and base metals making 
their appearance in the ore. 

Occasional natural deposits of chloride of silver and some rare 
instances of native silver, unaccompanied by sulphides, form, with 
certain decomposed ores, the chief types adapted to fi-ee-milling; though 
the process being cheaper than roasting-milling, ores are sometimes 
worked by it, which should properly be roasted, but the percentage saved 
in such cases is correspondingly low. Ores carrying quite a large per- 
centage of base minerals may be worked by roasting-milling, but in many 
cases it is more profitable (when the conditions admit of it) to treat such 
ores by concentration and smelting. The presence of certain minerals in 
combination may render the chloridizing roasting of an ore extremely 
difficult. The Silver King mine in Arizona may be cited as an instance 
of this, as mentioned by Mr. Aaron.* 

The ore in question consisted largely at one time of fahlerz, chlorides, 
bromides, and oxides, in a gangue of quartz and heavy spar, and being of 
high grade it proved well adapted to treatment by the Kiss lixiviation 
process, for which it had to undergo a preliminary chloridizing roasting. 

It was found that this ore sustained a serious loss of silver by volati- 

* Report of the Director of the United States Mint. 



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PROCESSES OF OKE TREATMENT. 281 

lization during roasting ; an extra draught produced by opening both ends 
of the fireplace somewhat mitigated the difficulty, but it was only finally 
overcome by introducing steam into the furnace (as originally suggested 
by Dr. Percy) which successfully met the difficulty ; the volatile metal 
chlorides (to which the volatilization of the silver is mainly owing) being 
decomposed and converted into oxides, with the instantaneous production 
of hydrochloric acid. Unfortunately, however, as depth was reached in 
the mine the character of the ore changed. The proportion of chloride 
and tetrahedrite fell off, and zinc blende and galena became more abundant, 
and this led to far more serious difficulties. 

The roasting became alow and tedious ; while previously a charge of 5 
tons could be well roasted in 14 to 16 hours, converting about 95 per cent, 
of the contained silver into chloride. The percentage of soluble silver in 
the roasted ore decreased also somewhat, causing richer tailings, and as 
the grade of the ore likewise fell off, a serious diminution in the output 
of bullion ensued. The ore, moreover, developed a tendency to ball 
and form crusts on the furnace walls. The balls were peculiar, being 
perfectly spherical and of all sizes from a pin's head to a marble, extremely 
hard, and consisting of concentric layers. The ore being crushed wet and 
received into settling-pits, no doubt operated disadvantageously in this 
instance. 

When the ore was by no means at its worst, analysis showed it to 
contain 12 per cent, of zinc — equivalent to about 18 per cent, of blende, 
6 per cent, of lead as galena, a good deal of antimony, a little arsenic, a 
very little iron and copper, and trifling quantities of cadmium, selenium, 
tellurium, and bismuth. The conjunction of antimonial and plumbiferous 
minerals with zinc blende tends in fact to make roasting difficult. The 
character of the gangue also exercises a great influence on the roasting. 
The presence of quartz is advantageous, spar or gypsum is not troublesome, 
but earthy carbonates are detrimental, and magnesia bad. 

At one time the ore contained less quartz and spar than formerly, and 
more of the so-called porphyry of the district, which contains magnesia 
in abundance. 

In the case of ore which balls in the furnace when roasted with salt, 
the usual practice is to roast without salt, to a certain stage when the salt 
is added and the heat increased; but the presence of metallic silver and the 
absence of a fair proportion of iron rendered this method inapplicable. 

The next idea tried, that of roasting to complete oxidation without salt, 
and then chloridizing by an addition of calcined copperas and salt, has been 
used with a slight modification on some of the worst ores with good results. 



Digitized by VjOOQ IC 



282 PROCESSES OP ORB TREATMENT. 

Another successful plan was to mix a certain proportion of sand, about 
7 per cent., with the charge. The sand used contained a little silver, being 
the coarser portion of a pile of rather rich tailings from previous concen- 
tration. The addition of one-third of clean quartzose silver-ore was found 
to act favourably, 95 per cent, of the chloride being got out in 24 hours 
with 3 ton charges. 

Mr. Stetefeldt has lately introduced the plan of drying and roasting 
ore with gas, at the Holden mill. Aspen, Colorado, and at the Marcac 
mill, Park City, Utah, where lixiviation is employed for the treatment 
of the ore. The former plant was put in operation in November, 1891, 
and consists of four double shelf-driers, with one 6 feet diameter Taylor 
revolving-bottom producer, and one lai^e Stetefeldt furnace, with a Taylor 
producer, also 7 feet in diameter. Mr. Morse, the general manager of 
the Holden works, states that, on a recent run of 4,631 tons of ore, 96'4 
lbs. of coal were used per ton of ore roasted, costing 14*45 cents. The 
coal, consisting of a mixture of about equal proportions of Colorado New- 
castle and Sunshine coal, costing 3'00 dols. per ton delivered at the 
mill. The composition of these coals are : — 





Fixed 
Carbon. 
Per Cent. 


VolatUe 
Matter. 
Percent. 


Aflh. 
Per Cent. 


Water. 
Percent 


Colorado Newcastle ... 


... I. 55-9 .. 


.. 85-9 . 


6-4 . 


.. — 


»i ij 


... 11. 48-6 . 


.. 37-95 . 


.. 11-6 . 


.. 1-7 


„ Sunshine 


... III. 480 . 


.. 4.S-0 . 


.. 7-6 . 


.. — 


» »» ••• 


... IV. 371 . 


.. 36-3 


.. 23-8 . 


.. 2-8 



This, Mr. Stetefeldt states, is the cheapest drying and roasting on record 
in any silver-mill, and the introduction of the system of employing gas 
producers is making rapid progress in silver-milling. Full details of the 
cost of drying and roasting at Aspen on a run of 12,000 tons of ore are 
given in the The Engineering and Mining Journal^ New York, of June 
26th, 1892.* 

When ores contain a very large percentage of sulphur : »>., are 
exceptionally heavy. Mechanical roasting furnaces cannot, as a rule, 
compete with the old-fashioned reverberatory furnace, but, with a mode- 
rate amount of sulphur, many of them give excellent results. The cost 
of roasting (chloridizing) in the Stetefeldt furnace is said to vary from 
16s. to £1 Os. lOd., and the furnace is said to cost £625 to buQd. A 
Bruckner fiimace, which is a favourite in small mills, will treat from 
3 to 4 tons (in exceptional cases 10 tons; in 24 hours. The cost of roast- 
ing in it varies from lOs. to £1 per ton. An improved form, with double 
cylinders set tandem, is estimated to roast 20 to 40 tons of refractory ore 
(in inverse proportion to the percentage of sulphur it carries) at a cost 

♦ Page 660. 



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PROCESSES OF ORE TREATMENT. 288 

of £4 88. 4d. per day, f.^., 2s. Id. to 4s. 2d. per ton. Mr. Briickner's 
estimate of the cost of a double-cylinder plant is £2,255 erected. 

In many of the best modern mills where dry-crushing is practised 
the furnaces are placed at the extremity of the battery line, a little be- 
hind it, and not in front, as they used to be. 

Mechanical furnaces of the improved Bruckner and Howell- White 
type (a modification of a Hocking and Oxlands calciner), and the Stete- 
feldt and O'Harra are amongst those in most general use. 

If the ore requires roasting, dry stamps are invariably used, the 
mortars being covered in with a wooden housing, to which exhaust fans 
are attached to draw off the dust into pockets (emptied at intervals), 
and the dry ore is moved by screw-conveyors or horizontal endless-belt 
tables to the feed-pocket of an elevator, which raises it to the hopper of 
the furnace if a mechanical roaster be employed.* When the ore is 
roasted a chlorination assayt must be made of every charge. 

The floors of modem wet-crushing mills are laid slightly inclined 
towards a reservoir connected with the pulp-tanks, double-planked and 

• tarred, and the mill supply of quicksilver is almost always handled 
mechanically by a mercury pump. It is imperative, however, that it 
should be of first-class make, as a poor device for handling quicksilver is 
more extravagant than hand labour. 

The variations in the details of the plant and method of manipulation 
are capable of so great a number of permutations that it would be use- 
less to attempt to go into the subject fully in this paper. The author 
should, however, state that the fineness to which the ore can be reduced 
is to no small extent determined by the capacity of the settlers to work 
off the coarse sands without loss of mercury. 

Although it has been found by experience that some ores roast as well 
if crushed through a 80 as they would through a 40 mesh screen ; some 

* heavy ores, ue., those that contain a great deal of sulphur, give a low 
chlorination and extraction, unless crushed finer, say to a 50 mesh. The 
limit of coarseness to which it is ordinarily practicable to carry crushing 
with stamps is, the author believes, about 80 mesh. 

* A new form of elevator and conveyor made by the Jeffrey Manufacturing Co., 
of Columbus, Ohio (a description of which is given In The Engmterlng and 
Mining Journal, New York, of March 4th, 1893, page 201), consisting of a steel 
cable, to which a number of iron diaphragms of suitable shape are attached at 
intervals, which travel in a trough of corresponding shape, would seem to be par- 
ticularly applicable to this purpose. 

t The method of doing this is excellently described by Kust^l, Bocuting of Gold 
and Silver Ores^ second edition, 1880, page 32, et seq. 



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284 PB0CE88E8 OF OBB TREATMENT. 

It cannot be too strongly emphasized that one of the most important 
points in pan-amalgamation is cleanliness about the works, and the use 
of clean quicksilver ; though order and neatness, with the polish that 
comes of the use of elbow-grease, are factora of economy that ought to 
be naturally looked for in all mining plant. 

Bichloride of copper is supposed to be the active agent in the Washoe 
process in the reduction of sulphide of silver; just as bichloride of 
mercury* attacks gold and amalgamates with it when ordinary quick- 
silver will not touch the yellow metal. 

If it is worth while putting up a well-constructed mill building (which 
cannot be done without corresponding expense) it is worth while keeping 
it in first-class repair. 

The cost of an ordinary 20 stamp dry-crushing plant, including 
rock-breaker, mechanical-drier and roasting-fumaoe, cooling-floors and 
elevators, with stamps and conveyors, and the necessary pans, settlers, 
sluices, etc., with a quicksilver-tank system, will not, in most cases, fall 
far short of £7,100, in Ijondon, exclusive of local freight and erection 
charges. It would weigh about 234 tons. 

The cost of a 20 stamp wet-crushing silver-mill plant, with rock- 
breaker, automatic-feeders, stamps, pulp-tanks and pans, settlers, etc., 
will not generally come to less than £6,525, and weigh about 186 tons. 

The cost of treatment, milling ores wet, varies from 12s. 6d. to £1 178. 
6d., employing the Washoe process. A high avenge being about 18s. 
9d. per ton. 

The cost of treatment, milling ores dryt, varies from £1 5s. to £2 lis., 
and when the ore requires roasting it will average from £1 13s. 4d to 
£8 2s. 6d., and sometimes as high as £5 16s. 8d. per ton. 

The great variations in silver ores, conditions of working, and methods 
of extraction make it impossible to give more than very general estimates 
of cost, as it fluctuates frequently in the same district, with differences 
in price of fuel, labour, freight, chemicals, etc. 

♦ The DesignoUe process. 

t The writer alludes here to a modification of the Reeee River process, which 
dispenses with roasting ; as examples of which, we have the Bberhardt at White 
Pine, and the Lancaster mill at Tuscarora. It is practised on the grounds that a 
much higher percentage is saved, if the ore contain chlorides, as the finely divided 
horn-silver is likely to be lost if crushed wet, although the slimes are thin. It is 
applicable also to some ores which produce an excessive amount of slime, which 
escapes the settling-tanks. 



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PBOOESSES OF QBE TBEATMBNT. 



285 



A 26 stamp wet-cruflhing silver mill, running 24 hours, generally needs 
the following crew of men : — 



2 Tock-bFeakermen. 
2 battery feeders. 
2 amalgamators. 
2 engineers (and in some cases * 
firemen). 



1 mechanic. 

1 foreman and assayer. 

2 assistant amalgamators. 
8 tank-men. 



The Grand Prize* (a 20 stamp dry-crushing and chloridizing mill) 
employs : — 

No. of 
Men. 

2 amalgamators 

2 „ helpers 

2 chloridizers , 

2 „ helpers , 

2 battery feeders (tenders) 

2 engineers (drivers) 

4 firemen , 

1 melter and retorter 

6 dry-kilnmen • , 

1 blacksmith 

4 labourers , 





H^' Shift? 
JB 8. d. 


at 1 10 




... „ 16 8 




..,.10 10 




.. „ 16 8 




..,,10 10 




..,,10 10 




.. „ 16 8 




.. „ 16 8 




.. „ 16 8 




..,,10 10 




.. „ 16 8 



The Lancaster* (a 10 stamp diy-crushing raw-amalgamating mill) 
employs : — 



No. of 
Men. 


Hours Shift. 
£ B. d. 


2 amalgamators 


at 1 10 


2 „ helpers 


„ 16 8 


2 battery tenders 


„ 16 8 


2 engine drivers 


„ 1 010 


8 firemen 


„ 16 8 


2 dry-kilnmen 


, 16 8 


3 labourers 


„ 16 8 



16 

Examples of the Washoe Process. 

The ores of Mineral Hill, Nevada, consist of chloride of silver, bromide 
of silver, argentite, polybasite, stephanite, carbonate and molybdate of lead, 
carbonate of copper, and some manganese, occurring in a limestone-forma- 
tion in irregular deposits. Mr. Eisslert states that, being of a complex 
character, they were originally treated by roasting milling, but he 

♦ Bgleston, Metallurgy of Silver^ page 437. f The Metallurgy of Silver^ page 166. 



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286 PROCESSES OF OBB TBEATMENT. 

subsequently worked them successfully on the Washoe principle by dry- 
crushing and amalgamation (the modification of the Reese River process, 
before alluded to). 

A point of special interest is the presence of bin-oxide of manganese in 
the ore. This mineral appears to have a deleterious effect on the amalga- 
mation, its presence being indicated in the settlers by a thick froth, which 
in spite of dilution with water, carried off flowered quicksilver; The 
charge, Mr. Eissler states, which gave the best results, was found to be 
1,500 lbs. of ore mixed in the pans with 15 to 20 lbs. of salt and 8 to 5 lbs. 
of bluestone. Treating 18 tons per diem, the cost was as follows : — 



Superintendent, who also acted as assayer 

Master mechanic 

Carpenter 

Two engineers at £1 Os. lOd., 1 day and 1 night 

Two men tending rock-breaker at 16s. 8d. 

One man at dry-kiln, and to take battery samples, 1 day 

and 1 night 

Two battery-feeders, 1 day-and 1 night at 18s. 9d. 

Two pan-men during the day • 

Two pan-men and one retorter at night 

400 lbs. of salt at 3d 

8 cords of wood at £1 5s 

Loss of mercury, 30 lbs. at 5s 

Wear and tear of iron, and repairs 

Oil and incidentals, sulphate of copper and assay 

materialB 



£ 8. 


d. 


2 1 


8 


1 5 





1 5 





2 1 


8 


1 13 


4 


1 13 


4 


1 17 


6 


1 13 


4 


2 10 





5 





10 





7 10 





4 8 


4 


3 2 


6 



Cost per ton, £2 lOs. lid. 



£45 16 8 



The ores of Pioche, Lincoln County, Nevada, which contain on the 
average 8 to 5 per cent, of lead (cerussite and galena) have been treated 
successfully by the ordinary Washoe process, the ore being worked up to 
over 82 per cent. ; when assaying £27 Is. 8d. per ton and yielding bullion, 
the average fineness of which was somewhat below 700, containing lead 
and some copper. 

To extract the greater part of the lead, the quicksilver and amalgam 
after leaving the settlers was strained in sacks suspended in a large box 
filled with water, heated with steam by a ^ inch pipe. Lead amalgam 
at the temperature of boiling water remains liquid, and will therefore 
strain through with the excess of quicksilver. As a certain amount of 
silver and copper amalgam also passes through, the mercury is run into 
a smaller box oooled with water, and when cold strained in the usual way, 



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PB00BSSE8 OF QBE TREATMENT. 287 

leaving an amalgam of lead containing a small amount of the other metals. 
This lead amalgam, when retorted, gave bullion containing 6 to 20 per 
cent, of silver, very little copper, and only a trace of gold. The amalgam 
in the first sacks gave bullion from 550 to 680 fine in silver, and finer in 
inverse proportion to the amount of copper in the ore. 

The amalgam from the second straining of the quicksilver, with ore 
of normal character, gave bullion 60 to 200 fine. When the ore was 
amalgamated without chemicals the bullion was 300 to 350 fine, and when 
amalgamated with salt and bluestone, but not strained in hot water, 400 to 
460 fine. The ore contains on an average £1 Os. lOd. in gold to over 
£20 16s. 8d. worth of silver, this proportion remaining very constant. 
45 to 55 per cent, of this gold is extracted. The bullion contains 0*0003 
to 0*0015 parts of gold, and occasionally as high as 0*0030 parts. With 
bullion 500 to 600 fine (after passing through the hot-water straining 
process) the loss of quicksilver amounted to 4| lbs. per ton of ore, due 
probably to the formation of chloride of lead and the subsequent formation 
of sub-chloride of mercury. Another source of loss was the formation of 
floured lead-amalgam, which had the dujl appearance of lead and floated 
off in flakes on the surface of the water. The chloride of copper formed 
rapidly destroyed the castings of the pans. The proportion of retorted 
bullion to amalgam in working the Comstock, White Pine, and Idaho ores 
is as 1 to 5 i to 6 : in amalgam containing a large amount of copper as 1 
to 7 to 7^ ; and in very base amalgam as 1 to 4.* 

The ores of the Silver Reef in the Harrisburg district, Utah, are of a 
remarkable character, consisting of chocolate-coloured sandstone with fine 
chloride of silver disseminated through its mass, and where organic remains 
(such as leaves and stems of trees) are found embedded in it, the silver is 
present in a pure metallic state. In the Stormont mine, the ore is found 
in a zone 10 to 100 feet thick, often associated with fossil-remains, etc., 
and is bounded by red sandstones above and white sandstone below. The 
ore is very easily crushed and disintegrated, a 750 lbs. stamp putting 
through 7 to 8 tons per 24 hours' crushing through a 40 mesh screen, so 
that 5 to 10 stamps will more than supply 12 pans, working 1^ tons pan 
charges. Oonsidering the size of the mills, the cost of milling is in con- 
sequence extremely low. The ore averages £6 5s. per ton. The tailings 
vary greatly in richness, according to the character of the ore. With 
sandstone ore, they will often carry 12s. 6d. per ton, while with shaly 
ore they may run £2 Is. 8d. or more. 

* Eissler, Metallurgy of Silver ^ page 133. 



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288 paooESSBS of obb treatment. 

Mr. R. P. Rothwell gives the cosb of a year's working at three of the 
mills of the district as follows : — 



Ohrinty M. and 
Mff. Co. 

PertoaofS.00011». 14.Si9tons. 




Stormont Leeds Co. 

Co. In 1878 In 1879 
9.963 tons. 13.064 tons. 4.679 tons. 
^ s. d. £ s. d. £ s. d. 


Labour &8alarie8 11 10^ 




12 4^ 9 2 


— - 


Bluestone .. (2*1 lbs.) 1 3^ 


(If 


lbs.) 1 1 1 




Mercury ... ( 1-22 lbs.) 2 6 


( 1-13 lbs.) 2 4^1 




Salt (25-8 lbfl.)0 2 IJ 


(20-00 lb8,)0 1 21^0 13 5 




Fuel 5 54 




1 lor 




General supplies 3 7J 




1 lOi 




Incidentals ... 1 8^ 




6 




£18 6 


£1 1 4 £1 2 7 


£0 17 2 


Hauling ore to mill 3 0^ 




8 4 14 


1 04 



In parts of Mexico, silver ore which fells below £6 5s. per ton is not 
available for the Washoe or patio processes, owing to the excessive cost 
of transport, and fuel. At Guanajuato, for example, packing on mules 
costs 14s. 7d., and treatment of the ore £2 78. lid., whilst mining, 
pumping, hoisting, etc., add a further charge of £2 10s. Wood costs 
£2 Is. 8d. and coal £4 lis. 8d. per ton. The district, however, is said 
to be a rich one, one group of mines north of the city of Guanajuato 
being credited with a production of 812,860,000 dollars between 1548 
and 1889, out of a total of 650,000,000 dollars worth of silver obtained 
from the district. 

Mr. W. L. Austin gives* the subjoined particulars of the cost of 
running a wet-crushing silver-mill in the Tombstone district, stating 
however that, owing to the arrangement of the plant, which works under 
some disadvantages consequent upon its alteration from dry-chloridizing 
to wet-crushing and other reasons, a reduction of 20 per cent, in the cost 
of milling could be effected under more fevourable circumstances. 

A novel feature to be noticed is that the shoots leading from the ore- 
breaker to the bins are not only provided with the ordinary grizzleys, the 
bars of which are set f inch apart, but the bottom of the shoot itself is 
fitted with a shaking-frame covered with screens of the same mesh as 
those used in the battery. 

This relieves the batteries materially, and decreases the amount of 
slimes, increasing the capacity of the mill 5 per cent, or more, depending 
on the fineness of the o/e and its percentage of moisture, as the ore fine 
enough to pass the screens, goes direct to the pans without passing 
through the battery at all. 

• " Silver Mining in Arizona." Tram. Am, Inst, Min, Eng,^ vol. xi., page 91. 



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PR00BS8B8 OF OEB TREATMENT. 



289 



The average gross weight of the stamps is between 750 and 800 lbs. 
The shoes, weighing 120 lbs., have an average life of one month, when 
worn down to about 85 lbs. 

Hendy Challenge feeders are used, and the stamps crushed 2*9 tons of 
medium hard rock in 24 hours for the first six months they were in 
operation, using a 80 mesh screen. 

After 4 hours' grinding in the pans, the average extraction was found 
to be about 81'04 per cent., and nothing material was gained by prolong- 
ing the treatment, but by the use of salt and bluestone 87 per cent, could 
be got out of the ore, which contained only 7 per cent, of its silver as 
chloride. 

So long, however, as coarse crushing was adhered to in the battery, 
the buUion was much debased. The remedy was found to be to crush 
finer, using 35 mesh screens and amalgamating without grinding in the 
pans, by which means the bullion was kept at '970 fine without sacrificing 
the milling percentage. The ore contains about 8s. 4d. in gold, and 43 
per cent, of this was also recovered. It may be mentioned that the 
debasing of the bullion was chiefly due to lead, which lowered it down to 
•200 and '300, and whenever wulfenite appeared in the ore this was 
remarked to a much greater extent than when the lead was in the form 
of cerussite or galena. 

The average cost of milling for five months was with 20 stamps : — 







£ 8. d. 


Labour 




.. 10 6 


Fuel 


... .. 


... 4 4^ 


ChemicalB and 


mercury 


... S 2J 


Lubrication 


... 


... 2 


Illumination 




... li 


Castings ... 





... 1 4i 


Supplies 





... 8 



Per ton 



.£1 6 



The cost of labour (subdivided) treating 1,730 tons, based on one 
month's work waa estimated to be : — 





B. d. 


Crushing 


. 2 2 


Amalgamating 


2 94 


Power-pumps, etc 


1 in 


Foremen, etc 


3 74 


Tailings-pits 


5i 


Per ton 


U 


VOL. V.-18W 88. 





19 



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290 PROCESSES OF ORE TBEATMENT. 

The loss of mercury averaged about 58. 5d. per ton, and about 0*11 
cordfl of wood,* and 1,200 gallons of water, were consumed per ton milled. 

Mr. Austin also gives another instance of the cost of wet-crushing in 
Arizona, estimated on 2,643 tons crushed in a 20-stamp battery, fur- 
nished with a rock- breaker and automatic feeders, separating the coarse 
sands in hydraulic sizing-tanks, and working each sand-class by itself, 
for which the ore alluded to was particularly suitable, being entirely free 
from base metals with a gangue of light specific gravity. 

The stamps weighed 800 lbs., and put through on an average 6 tons 
per head in 24 hours. 

Cyanide and lime, in the proportion of 14 lbs. of the former chemical 
and 120 lbs. of the latter per. 100 tons of ore, were used in the pan 
treatment. The mercury was pumped through the mill for distribution. 

The motive power was a 200 horse-power horizontal engine (42 inches 
by 20 inches cylinders, run at 60 revolutions per minute), and the boilers, 
which were tubular, 15 feet 6 inches by 54 inches, carrying 85 lbs. steam 
pressure, burnt 16 cords of wood irrespective of the boiler for the pump, 
which burnt 8 cords per week. The cost per ton of ore was : — 

£ 8. d. 

Labour 5 IJ 

Supplies 7 7 

Assaying 4 6i 



17 2 



The cost for labour as given above is thus subdivided : — 

£ 8. d. 

Crushing Oil 

Amalgamation 10 

Power, pumps, and repairs 1 8 

Foreman, melter, etc 1 6^ 



6 1^ 
The cost of material as given above is thus subdivided :— 

£ 8. d. 

Mercury 19 

Chemicals 3^ 

Castings 1 2i 

Illumination and lubrication 3} 

Fuel, including pump 3 3 

Supplies .. 9J 

7 7 

♦ This includes pumping the water supply 200 yards (with a lift of 100 feet 
vertical); 7 cords of mixed wood (black oak, white willow, and pine), costing 
£1 17s. 6d. per cord, were used on the average per day. The mill engine was pro- 
vided with a Meyer cut-ofE. 



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PROCBSSBS OF OEB TREATMENT. 291 

The consumption of wood per ton of ore was 0*15 cords, and of 
mercniy 0*96 lbs. 

The bullion averaged -995 fine. 

Stated in gallons, the quantity o£ water used per boiler in a silver- 
mill is 7J gallons per horse-power per hour. For each stamp, 72 gallons 
per hour ; for each pan, 120 gallons per hour; and for each settler, 60 
gallons per hour. 

The consumption of wood (not including that used for roasting) in a 
dry-crushing mill is put by Prof. Bgleston at about ^ cord per ton. 

The power required for a Bruckner roasting-cylinder is estimated at 
about 2 horse-power, and for the Ho well- White 1 J horse-power. 

The ore according to its baseness loses 3 to 15 per cent, by weight in 
roasting. 

The value of stock on hand necessary to run a dry or wet-crushing 
silver-mill, including wood, mercury, castings, chemicals, etc., is very 
variable. 

Examples op Roasting Milling Treatment. 

The ore of the Ontario mine is a very base one, being composed of 
zinc, lead, and silver sulphides and silver chloride in a quartz gangue. 
This becomes baser with the increasing depth of the workings. The 
bullion obtained runs about 600 fine and contains no gold. The average 
grade of the ore treated is 100 to 180 dollars per ton, and the amount 
treated varies from 60 to 55 tons per day, though formerly (when it was 
less base) 65 tons were handled daily. The ore is roasted in Stetefeldt 
furnaces with the addition of about 16 per cent, (dry weight) of salt. 

After leaving the furnace the ore goes to the cooling-floor, where it 
remains piled up for 18 hours. This increases the chlorination from 8 to 
8 per cent. After being damped it is run to the pan-room. Each pan- 
charge of ore weighs 2,500 lbs., to which 1 per cent, of salt is added, and 
the pulp made up with the addition of hot water to proper consistency. 
The muUer makes about 65 revolutions per minute, and is held 1 inch 
above the pan-bottom so that it does not grind. About 1 lb. of zinc 
and 800 lbs. of mercury are added to the pan after it has run 1 hour 
(and is hot), and amalgamation is continued for 7 hours. From the pans 
the pulp is drawn into settlers, which run 4 hours, making 40 revolutions 
per minute, and after running for 1 hour cold water is let in, and the 
overflow discharging the tailings is set running. The mill is worked up to 
from 88 to 92 per cent, of the value of the ore, that being counted as the 
amount chlorinated. The tailings carry off 8 to 12 per cent, of the silver. 



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292 



PROCESSES OF OBE TREATMENT. 



The cost of treatment on a production of 50 tons per day was stated 
as follows* : — 



No. of 
Men. 








PerDfty. 
DoUan. 


Per Ton. 
£ 8. d. 


1 ... 


Foreman... 


... 


... 


.. 10-00 ... 





10 


1 ... 


Assayer ... 


... 


... 


6-00 ... 





6 


3 ... 


Machinists 


at 1400 


12-00 ... 





1 


2 ... 


Carpenters 


at 


4-00 


800 ... 





8 


2 ... 


Blacksmiths 


at 


4-00 


8-00 ... 





8 


2 ... 


Engineers 


at 


4-00 


8-00 





8 


2 ... 


Foremen 


at 


3-50 


7-0(» ... 





7 


9 ... 


Dry-floormen 


at 


3-50 


... 31-50 ... 





2 7i 


3 ... 


Batterjmen 


at 


4-00 


... 12-00 ... 





1 


6 ... 


Roasters 


at 


400 


... 24-00 ... 





2 


12 ... 


Cooling-floormen at 


400 


... 48-00 ... 





4 


4 


Carmen 


at 


4-00 


... 16-00 ... 





1 4 


4 ... 


Amalgamators at 


4-50 


... 18-00 ... 





1 6 


1 


Retorter 
Melter 


at 
at 


4-00 \ 
4-00/ 


8-00 ... 





8 


4 ... 


Labourers 


at 


2-50 


... 10-00 ... 





10 


4 ... 


Watchmen 


at 


3-00 


... 12-00 ... 





1 


2 ... 


Ore-floormen 


at 


3-50 


7-00 ... 





74 


3 ... 


Clerks 


at 


4-00 


... 12-00 ... 





1 


66 


1267-50 


£1 


1 6 




SuppiieB. 






Per Day. . 

DolUn. 


Per Ton. 
£ 8. d. 


Salt, 10 tons at $8'00 


... 


... 80-00 ... 





6 8 


Quicksilver, 175 lbs. at 


0-50 


..■ 


... 87-60 ... 





7 34 


Wood, 15 cords at 


4-50 


... 


... 67-50 J 
... 99-00) "■ 





14 84 


Coal, 12 tons at 


8-25 




Castings 


... 




... 


... ... 





6 3 


Oil and waste 




... 








1 04 


Sandries, chemicals, etc 


... 


... 


;,. .,, 





2 1 


Haaling 


From mine ... 


... 


... 


... ... ... 





2 04 


Charcoal, 


assaying, and 


melting 










1 04 



£2 1 14 
Total cost per ton, £8 28. T^d., exclusive of office expenses, general 
superintendence, repairs, and insurance. 

The report of the Granite Mountain Company, Phillipsburg, Montana, 
one of the largest dry chloridizing roasting-crushing plants in America 
(running 153 stamps), gives the following particulars of working for the 
year ending July 81st, 1891 : — 

Ore, tons crushed, wet, 72,623 = dry weight, 68,860 
Salt, „ „ 10,807 - „ 10,645 

Total 83,480 79,496 

Average moisture in the ore, 5-2 per cent. ; average moisture in salt, 1-5 per cent. 

• R. P. Rothwell, TrtJM. Am, Ituft. of Min, En^., vol. viii., page 557. 



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PROCESSES OF ORE TBEATMEKT. 298 



The salt and ore are mixed before croshiBg. 

The ore averaged 60*69 omioes of silver, and the cost of milh'ng was 
£2 Is. 8d. per dry ton, divided as follows : — 



Labour and saperintendence 

Salt ... 

Fuel ... 

Mercury 

Castings 

Chemicals 

Water ... 

MiscellaneouB 




£2 ] 8 

Equal to £1 198 S^d. per wet ton. 

The company's three mills, of 20, 43, and 90 stamps respectively are 
known as A, B, and 0, and have cost, with improvements np to date, 
£146,843 17s. 9 Jd., as shown by the trial balance sheet. The cost varied 
from £1 16s. 7id. in mill 0, which crushed 42,153* wet tons, to 
£2 lis. lOd. in mill A, which crashed 9,934t wet tons. 

The saving of silver amounted to 90*7 per cent. 

The report of the Elkhom Company, of Montana, for 1891, affords 
another excellent illustration of close saving and business-like manage- 
ment. 

The mill, which crushed 11,646 tons (dry) during the 12 months 
ending December 81st, 1891, saved 93*78 per centj of the silver contents 
of the ore at a cost of (9*226 dollars)§ £1 18s. b^d,, a close approxi- 
mation to the figures just given. 

Tailings Mills. 

Silver-mill-tailings are generaDy concentrated on concentrators, or on 
blankets, in sand-sluices, and either leached, or treated in pans on the 
Oomstock system (using chemicals) ; which has given rise to what are 
known as tailings, or auxiliary mills. 

Tailings from silver mills can in fact often be treated profitably by 
storing them in dams, leaving time, air, and chemical agency to effect 
their oxidation, and then treating them raw in pans, no drying or chlor- 
idizing being required. 

The chief drawbacks against this method are the uncertainty as to the 
time necessary for complete oxidation of the minerals present, which may 
be taken from 2 to 4 years, and the necessity of constructing large 
storage dams. 

♦ Representing 40,067 dry tons. t Representing 9,318 dry tons, 

t In 1890, 86-88 per cent, was saved, the increase In 1891 is attributed to using 
extra salt. § For analysis, see Appendix. 



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294 PROCESSES OP ORE TREATMENT. 

Mr. Eifisler states* that, in some establishments of this kind in 
Nevada, the quantity of sulphate of copper supplied to the pans with this 
system of treatment varies from 3 to 6 lbs. per ton of tailings, while the 
salt amounts to 20 or 30 lbs. The pans are covered, and supplied with 
steam at a high temperature. 

He places the yield at about 60 per cent., dealing with an ore worth 
£3 to £3 lOs. per ton, and gives the current cost as follows : — 



Laboar 


6 


Quicksilyer lost 


4 


Salt 


8 


Sulphate of copper 


2 6 


Fuel 


6 


Castings 


6 



Total £1 1 

In Avery's tailings-mills in Washoe valley, where wood is £1 48. 
per cord, the cost per ton is stated to have been 14s. 

It is usual in Nevada for two sets of samples to be taken as a basis 
upon which to determine the value of the ore, when it is treated at customs 
establishments. One of these samples is taken from the waggon conveying 
the ore from the mine to the mill, the other from the mill after the ore 
has been crushed. The waggon sample is obtained by drawing from each 
waggonload of ore a sample of rock, and mixing the total number of 
samples of the loads sent to any one mill at the end of the day. This 
bulk sample is then quartered down, the mill being charged with the 
weight of ore, and the amount of gold and silver represented by assay. 
The mill sample, which is to serve as a check on the waggon sample, is 
taken by allowing the crushed ore as it comes from the battery to run into 
a pail, held at the end of the trough leading to the tanks. 

A sample of this kind is taken in most mills every hour, in some every 
half-hour, aad the accumulated samples are well mixed, dried, and reduced 
to a sufficient quantity for assay. 

The pail or vessel in which the crushed ore is caught must not, of 
course, be allowed to overflow. 

In some mills the samples are taken from the tanks after the sand has 
deposited itself in them, either from the surface or preferably with a 
tube sampler. 

Strange as it may seem the waggon samples and mill samples generally 
differ in yield, and the former is usually the highest. 

This was proved in the late celebrated suit tried before Judge Hebbard, 
Fox versiis the Hale and Norcross Co. In practice, therefore, both assays 
are duly considered, and an adjustment arrived at. 

• The Metallurgy of Silver, page 114. 



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PBOCESSBS OF OBE TBEATHVKT. 295 

A. D. Hodges, in an interesting paper on pan-amalgamation,* esti- 
mating on 46,500 tons of Oomstock tailings treated at Drayton, Nevada, 
calculates the cost of treating them as follows : — 

a. d. 



Preparing and hauling 

Milling 

Qeneral expenses 



1 3| 
8 l| 
10} 



Total per ton ... 10 3} 

Some of the sand so treated seems to have ran about 15s. 3^. in 
silver, and 4s S^d. in gold, total £1, and yielded in bullion 75*8 per 
cent, of the silver, and 25 per cent, of the gold, total 68*8 per cent., 
whilst some of the slimes averaged £2 15s. 8d. silver, and 9s. 6^. gold, 
total £3 48. 8fd., and yielded 85'8 per cent, of the silver, and 42*5 per 
cent, of the gold, total 79 5 per cent. 

The loss of quicksilver, treating sands at Drayton, ran under ^ lb., 
and with slimes from | to 1 lb. per ton. 

The buUion from the treatment of the sands did not run over 150 
fine, and with the richer slimes the best results were got when it was 
from 200 to 250 fine. 

In Dakota, it may be mentioned that with free-milling gold ores, it 
cost 4d. for mill labour, to produce 4s. 2d. worth of gold. 

In Nevada, on the other hand, though over five times as much work 
is required per ton treated, it costs only about 3^., but this seeming 
contradiction is explained by the higher grade of the Nevada ores. 

A 20 pan mill, without any special arrangement for catching mercury 
working on tailings, made a gain of 700 lbs. of mercury in 6 weeks, which 
was but a small part of the mercury actually contained in the slimes. 

In view of these losses it generally pays to employ concentrators to 
work up the mill-tailings Sometimes a machine, known as a Yamey 
amalgamator, is set in the tailings-sluice. 

As battery slimes require no grinding it would seem most advantageous 
to charge the quicksilver direct into the pan, but experience has shown 
that better results are obtained by charging the chemicals with the 
slimes and thoroughly mixing them for about two hours with the muller 
up, and then adding the mercury, as the slimes form a pasty mass which 
might hold and carry off the finely divided quicksilver. In treating such 
material one-half its bulk in sand (tailings from the pans), and sometimes 
more, is added to the charge. 

In many so-called free-milling ores of silver, or silver and gold com- 
bined, there are small quantities of sulphides of the base metals, not 

• Trans. Am. Irut. Miii. Eng., vol. xix., page 231. 



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296 PROCESSES OF ORE TREATMENT. 

sofScient in quantity or value to make the ore suitable for roasting, yet 
enough to prevent a high extraction by free-milling, besides increasing the 
cost. Such ores can be best treated by the combined process of con- 
centration and amalgamation. 

Stamping the ore wet, passing it over copper plates, concentrating in 
vanners, and then amalgamating the tailings by the continuous process, 
lessens or dispenses with grinding in the pans, decreasing the wear of 
castings and fuel consumption ; decreases the losses of quicksilver ; 
increases the capacity of the battery by permitting coarser crushing ; 
raises the percentage of extraction, and gives higher grade bullion. 

The Montana Company by adopting this process obtained, it is said, 
an increased saving over ordinary pan treatment of from £1 13s. 4d. to 
£2 Is. 8d., decreased the loss of mercury to | lb. per ton of ore, and 
increased the tenure of the bullion from "500 to '900 fine. The cost of 
the process is from 12s. 6d. to £2 Is. 8d. per ton, and less water is re- 
quired than with ordinary pan-amalgamation. 

It is sometimes more expedient (depending on the base metals present, 
and the way the ore breaks) to crush finer in the battery and grind less, 
as before mentioned. 

Since ore will break naturally where there is most mineral, by dis- 
engaging it as far as possible in crushing, as mercury h<is a greater affinity 
for the precious than for the base metals, there is less likelihood of its 
becoming foul and inactive through taking up lead and other things 
which grinding tends to make it do. 

In Arizona the loss in melting bullion averaging '988 fine (from 
volatilization and skimmings) is stated by Mr. Egleston to be 7"56 per cent. 

Ores, like some of those of the Oomstock, that contain their gold 
and silver more or less free, will mill from 60 to 80 per cent, by the 
Washoe process and in exceptional cases, like those of White Pine (Nevada)/ 
and Silver Reef (Utah) to even 86 per cent. Roasting milling, on the 
other hand, gives an extraction of from 80 to 93 per cent., and in excep- 
tional cases 94 per cent. 

The combined process yields often 76 to 86 per cent. 

The Patio Process. 

This very ancient and interesting process cannot be passed by without 
comment, as Mexico, which ia its home, so to speak, is, it must be recol- 
lecterl, the second largest silver producer in the world, and it is safe to say 
that three-fourths to seven-eighths of the silver it returns is obtained by 
the patio process. 



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PROCBSSES OF ORE TREATKIiNT. 297 

The practice at San Dimas (State of Dnrango) may be considered 
typical, and is excellently described by Mr. R. E. Ohism,* whose paper 
contains detailed information on the subject. Englishmen and 
Americans alike have gone into Spanish America from time to time 
expecting to revolutionize this time-honoured system by introducing more 
modem metallurgical methods^ but in most cases they would appear to 
have failed in doing so, leaving abandoned reduction works all over the 
country as monuments of their errors. If we look for an explanation, it 
is to be found in the neglect of local conditions on which the success or 
failure of every process more or less depends. 

The patio, with its cheap plant and fairly close extraction in Mexico, 
where saving of time is a secondary consideration, where transportation 
is difficult, where the ores are rich, and where animal power, space, and 
labour are cheap, whilst fuel and other necessaries are dear (Central 
America possessing a suitable climate, and labour accustomed to the work 
from time immemorial) can, in fact, hold its own for the treatment of 
ores, which do not contain more than a trace of lead and zinc, where other 
processes would fail. 

The silver, which the patio yields, is almost free from impurities and 
baser metals. An assay of several bars showed an average fineness of 
0*994 silver and 0*035 gold. Mr. Ohism gives the cost of treatment in a 
large hacienda where the tahonas were in two groups, and were worked by 
gear connected with an over-shot waterwheel, where the breaking was 
done by wooden stamps shod with iron (also driven by a waterwheel), 
and where the washing was done by a water-power washer, working a 
trilla of 19 tons, as follows : — 

Breaking, grinding, and cost of tools 

Amalgamator's wages 

Scraping tahonas 

Carrying and washing scrapings 

Concentrating tailings of scrapings 

Carrying slime from tahona to patio 

Mules and keep 

Labour, spreading trilla and male driving 

Labour, washing trilla 

Charcoal, for retorting silver 

Concentrating tailings of trilla 

Materials- 
Salt. 600 lbs. at 4d 

Sulphate of copper, 125 lbs. at Is. OJd. 
Precipitated copper, 25 lbs. at 2r. 9d. . . . 
Quickailver, 133 lbs. at 2a. T^d. 

Total cost £5 12 IJ 

♦ Trans. Am. Inst. Min. Btig.y vol. xi., page 61. 





... 


Cost 


per Ton of S.OOO lbs. 
iS B. d. 

.17 9 

. 6 11 

.008 

. 5i 

. 3i 

.019 

. 15 6 

.068 

.024 

. 1 114 

.087 


10 


8. 



.. 


. 10 6^ 


6 
3 

17 


10 
8 
6 


2i .. 
9 .. 
4 . 


. 6 104 
,. 3 7i 
.. 18 2^ 



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298 PBOCBSSBB OP ORB TRBATMBNT. 

The cost to the owners would probably not exceed £5 4s. 2d., as the 
above costs include a certain charge for profit. 

At works where the tortas are of small size (about 10 tons) and the 
ore is broken without the aid of water-power, inclusive of superintendence 
and interest on plant, the cost is said to be £5 14s. lid. 

The concentrates obtained from the planilla-treatment and washing in 
the boliche are shipped and smelted in Germany. 

From 70 to 75 per cent., and in some few cases perhaps 80 per cent., 
of the assay value of the ore in silver is saved by the patio process, 72 
per cent, being probably about the average; whilst of the gold present 40 
per cent, is lost, 20 per cent, of the remainder goes with the silver, 
and the rest is recovered from the tailings or is caught in the tahona. 

The process from start to finish takes from 23 days to 7 weeks. 

In The Engineering and Mining Journal^ New York, of May 7th, 
1892,* Mr. E. du B. Lukis describes, what he claims to be, a recent 
improvement on the patio system specially applicable to ores containing 
antimonial and arsenical sulphides of silver, together with ordinary 
sulphides and some chlorides. 

The ore, instead of going direct to the patio after crushing, is first 
roasted for 10, 12, or 20 minutes. The object of this roasting is merely 
to give a quick start to the process, and while, owing to its rapidity, it is 
said not to entail a loss of over 1^ to 2^ per cent, of the silver by 
volatilization ; comparative trials have, it is asserted, proved the benefit to 
be derived therefrom. 

It is not desirable to roast sweet, but only to break up the molecular 
affinity of the particles of the mineral by heat, so as to hasten the progress 
of the after-chemical process with a view to save labour and time. 

The most important part of the modification in treatment, however, 
lies in the use of hyposulphite of soda, for if roasted ore be treated by the 
ordinary patio method it will not work, the quicksilver gets hot at once, 
and nothing can be done with it. 

It is also claimed that it is now possible to arrive at the quantity of 
sulphate of copper that will be required to beneficiate the cake from the 
start, reducing the treatment nearly to a certainty. To avoid the usual 
loss of quicksilver, the amalgamation is stopped before the difficulty of the 
patio treatment commences (when in fact the free silver ores have been 
amalgamated), the amalgam is then washed out in the usual way, and the 
more refractory silver minerals are concentrated. The results are stated 
to have been satisfactory, showing an extraction of 92 per cent, of the 
value. 

♦ Page 496. 



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FROGESBES OF OBE TRBATMEKT. 299 

The ores taken for trial were of a mixed class. One-third of the silver 
being antimonial or niby silver, the remainder mostly silver glance, but 
with pyritiferous silver ore and some chlorides. The assay value was 60 
dollars per ton. The heavy minerals amounted to about 10 or 15 per 
cent, of the whole. 

The ores were stamped dry to pass a 60 mesh screen, and roasted in 
an ordinary reverberatory furnace with a hearth measuring 8 feet by 6 
feet. The temperature was raised to a good red heat. Charges of 400 
lbs. were mixed with 2^ per cent, of salt, spread over the hearth and 
kept gently stirred with a rabble. Eight minutes after charging, a sample 
was taken out and washed in the tentadura or assay horn to show the 
. colour of the concentrates. It is by the colour that the calciner knows 
when to stop roasting. When suflSciently roasted, which does not in any 
case take more than 20 minutes, the charge is quickly withdrawn, and a 
fresh one introduced. 

The hot ore is allowed to remain in a pile until next day, when it is 
spread on the patio, moistened with water, and trodden into a soft pulp, 
with an addition of ^ per cent, of salt. This being done in the morning, 
sulphate of copper can be added three or four hours later. The required 
quantity can only be ascertained by experiment, but in the case cited 
4| ounces per 26 lbs. were found the right quantity. After this addition 
the pulp is again trodden and left till next day. 

Early next morning a guide \b taken from the cake by a peofi who 
walks across it in two diagonal lines taking small portions of the pulp 
here and there, and accumulating a sample as near as can be guessed of 
about 100 lbs. This is placed in a corner of the patio, and divided into 
four portions of 26 lbs. each, to each of which different quantities of 
sulphate of copper are added, say 1, 2, and 4 grammes (16, 30, and 60 
grains) respectively. Assays of each are taken in turn (conmiencing 
with the pulp of the cake itself), and mixed up with a globule of mercury 
in the tentadura and washed, when the action of the sulphate on the 
mercury will be seen by its colour. It ought to remain bright and quick, 
and sulphate can be added in small quantities to the guide until the 
mercury shows a trace of heat, i.e., becomes discoloured and leaden in 
tone, which indicates that a gramme (15 grains) too much per 25 lbs. 
has been added. 

The amalgamator now knows that he may add 1, 8, or 6 grammes 
(16, 45, or 76 grains) as the case may be per 25 lbs. of cake. Done with 
care and patience, this should be a sure guide as to the total quantity of 
sulphate the cake can stand. 



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300 PROCESSES OF ORB TREATMEKT. 

If the process were now continaed, as with raw ores, the mercury 
would become very hot by next day, and soon not work at all, that is to 
say become dirty in appearance and cease to form silver amalgam. To 
avoid this trouble, hyposulphite of soda has been used and found to work 
successfully, whilst it helps to hasten the process. It must, however, be 
employed with great care, the quantity being found by trial for determined 
mixtures of ore, and upon this depends its success. Roughly speaking, ^ 
ounce per 100 lbs. of pulp wiU be sufficient, more would destroy the 
mercury. 

Having decided upon the additional quantity of sulphate of copper 
that can be added on this the second day, and having trodden it into the 
pulp thoroughly, the hyposulphite of soda may be added and trodden < 
in the same way, and immediately afterwards the mercury should be 
sprinkled over the cake and trodden in, in such proportion as to take up 
by amalgamation two-thirds of the assay value, or 4 ounces of mercury 
per ounce of silver present. 

The following or second day after incorporating the mercury, treadii^ 
with horses, spading over, and taking assays will be all that is needed, 
unless it is found that a guide of 25 lbs. can stand an addition of sulphate 
of copper. This should not be necessary if the quantity be properly 
determined before adding the hyposulphite. More than half the mercury 
will be converted into amalgam by the evening. 

The following or third day after incorporating, the same work is 
required, paying more attention to the assays, and if necessary adding 
more sulphate of copper, and by evening more than three-quarters of the 
mercury will be taken up. 

The fourth day, the treading, etc., go on, and by evening the mercury 
should all be converted into silver amalgam, and should be bright and 
dry, and free from a straw-colour that indicates loss. The next morning 
the bafio or bath is added, consisting of 1 J ounces of mercury per ounce 
of silver in the cake, which collects the fine amalgam. 

This has to be done quickly, and the washing of the pulp follows 
immediately. The amalgam is collected, pressed, retorted, and the bullion 
in due course melted down. 

This treatment extracts that portion of the silver which cannot be 
concentrated, and it is found easy to concentrate the remainder on 
vanners, or other machines, obtaining, if necessary, two grades, the first 
assaying 1,500 ounces or over per ton, and the second 40 to 60 ounces. 
The waste is then too poor to treat further. 

These trials were made with an average temperature of 70 degs. Fahr. 
in the shade. 



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PROCESSES OF ORB TREATMENT. 301 

The loss of mercury, including the consumido and mechanical loss 
is said to be about 18 ounces for every 16 ounces of silver, as compared 
with 22 to 24 ounces lost in the ordinary patio. The gold is collected, 
if present, partly in the amalgam and partly in the high-grade concen- 
trates. The cost of working a ton of ore assaying 50 dollars is estimated 
at £1 5s. lOd., extracting 85 per cent, of the silver. 

The Fondo and Tina Processes. 

In South America, the patio process seems to have been used up to 
about 1830, when, in consequence of the large quantities of negros or 
sulphide ores, which began to be found there, * it was superseded by the 
fondo or calderon method, with variations known as the tina, Francke- 
tina, etc.* The original fondo process was invented, it is believed, in 
Chili, in the year 1609, by a priest, Albaro Alonzo Barba,t and was used 
for rich surface-ores, chlorides, bromides, and oxides, which, if not rich 
enough, required to be concentrated in the planilla, but it was on the 
whole a very slow process. 

The tina process in a modified form} is applicable to all ores of 
silver except argentiferous sulphides of copper, galena, or blende, and to 
ores which contain more than 1 per cent, of free arsenic, which causes 
great losses of mercury. The inventor is not known, but it has been in 
constant use about Copiapo since 1862. 

Prof. Egleston § says of it : — " The whole operation is very simple, 
quicker with much less loss than the barrel, more certain in its reactions 
than the patio, and is applicable to almost all the ores found in Chili. It 
is even cheaper under some circumstances than the lead-fusion." 

The cost of treating a ton of £8 6s. 8d. ore, not including interest 
on sinking fund, working 8 tons a day, is about £1 8s. T^d. 

The process now used in Bolivia, a modification of the tina and fondo 
processes, seems to be an advance on the former methods, as it includes 
many of the best points of the tina and pan processes, and may be used 
for base as well as docile ores of a great variety of yield. 

It is closely related to the Francke-tina method, which has been 
described by Mr. Edgar P. Rathbone || and Mr. Arthur F. VVendt. T 

Mr. Wendt says of the Bolivian method, " That large losses of silver 
were experienced through volatilization when the ore was roasted with 

• Egleston, Metallurgy of Silver ^ page 312. 

t Percy, Metallurgy of Gold and Silver , part I., page 656. 

J B&tme Universelle des MimJt^ series 1, vol. xzxi., page 493. 

§ Metallurgy of Silver^ page 323. 

II Proo, Inst, Mech, Eng., 1884, page 257. 

^ Trans, Am, Inst. Min. Eng., vol. xix», page 74. 



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802 PBOCESSES OF QBE TBEATMENT. 

salt in revolving mechanical fdrnaoes, and these conld only be obviated 
by an oxidizing roasting in reverberatories (following lump roasting in 
kilns), adding the salt after complete oxidation has taken place.*' 

The extraction remains practically the same, whether the chloridiza- 
tion of the ores is 20 or 90 per cent. This is so entirely different from 
the generally conceived notion of silver-milling in the United States that 
too much emphasis cannot be laid on this point. 

AU classes of ores can be worked by the process, not even excepting 
galena, although the extraction, with the latter and when blende is 
present, is of course reduced. The bullion obtained is generally '900 fine 
or over, alloyed principally with copper. Treating crude ore which 
carries 75 to 80 ozs. the tailings average about 10 ozs. 

The use of bluestone in pan-amalgamation with the object of produc- 
ing a sub-chloride of copper, which is an active agent in the pan process, 
has been commented upon before, but when an iron pan is used this sub- 
chloride is being constantly destroyed. When a copper or bronze vessel, 
however (like the tina), is used, the sub-chloride is, on the other hand, 
being constantly regenerate i, and this is the essential difference between 
the two methods, although of course the same results ciu b3 obtained at 
the expense of extra bluestone in the pan in dealing with base ores. 

The choice between the tina and the iron pan process must, therefore, 
Mr. Wendt thinks, depend on the relative price of sulphate of copper and 
iron-castings as compared with copper, to which must be added the extra 
refining charges, carriage, etc., on more or less coppery bullion. 

The cost at the Real Ingenio Potosi is stated to be 90 Bolivians (£4 
18s. 9d.) per cajon of 5,000 lbs., or about £1 17s. 6d. per ton, treating 
8 tons per day, but this is, of course, no criterion of what could be done 
with cheaper freight and better labour in works of large capacity. 

The process gives an extraction of 80 to 85 per cent, in Bolivia, and 
probably on rich chloride ores like those of Caracoles (worked by the 
Kroehnke process) it would yield returns running up to 92 to 96 per cent., 
as the extraction on roasted ores averages 90 per cent. 

The Leaching or Lixiviation Process. 

This process consists in first roasting the ore with salt to convert the 
silver into chloride, then dissolving the chloride of silver in a solution of 
hyposulphite of soda and precipitating it with sulphide of lime or soda 
(as a sulphide of silver) and refining this latter product. The Russel 
process is a modification of this, consisting in the use of what is known 



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PROCESSES OF OBB TBEATMElTr. 303 

as extra solation (prepared by adding a certain percentage of sulphate of 
copper to the ordinary hyposulphite solution) after the ordinary solution 
has extracted all the silver it will take out. 

Lower cost of plant and in some cases less expense in treatment are 
advantages which are claimed for leaching treatment, but against these 
must be set the difficulty of obtaining men with practical experience and 
chemical knowledge necessary to conduct the process, and the fact that 
the reactions involved are often obscure, and sudden disturbances in 
working, may be introduced by changes in the character of the ore. 

Since lixiviation was introduced into Mexico by Mr. Ottokar Hof mann, 
in 1868, it has become extensively used, and has risen to a position of 
importance in some parts of America for the treatment of refractory 
silver ores. AH silver ores are capable of being treated by it with a 
certain amount of success, except those which contain so much lead that 
they are classed as smelting ore, or which on account of a clayey-calcareous 
or talcose gangue, do not permit of free filtration. This latter objection 
can, however, be overcome, if other circumstances admit of it, by a previous 
slight concentration. The ore must first be pulverized to fit it for the 
process, and though this is purely a mechanical operation it does not 
follow that the machine which will crush the largest amount of ore at the 
least cost is necessarily the best to select. One has to consider as well in 
this connexion, the physical condition in which the ore leaves the 
machine, as on this depends to a great extent a most important part of the 
process — ^the roasting. Ores which contain a considerable amount of 
argentiferous galena or zinc-blende require to be pulverized very fine in 
order to ensure a satisfactory chlorination, while a coarser pyritic-pulp 
(whether consisting of iron or copper pyrites) will chloridize well. In 
selecting machinery for the purpose attention must therefore be paid (as 
in every other process) to the nature of the ore. 

The choice of crushing machinery, for an ore requiring leaching, lies 
mainly between rolls and stamps. The former produce a much more 
uniform grain than the latter (the ore and gangue-particles being of 
more even size), which is of distinct advantage for concentration, but 
may be the exact opposite for roasting. The most suitable condition of 
the pulp for roasting in dealing with ore of the kind described, is, in 
fact, a mixture of fine ore-particles in a coarse gangue, a condition of 
pulp which is promoted by dry-crushing with stamps. This is explained 
by the fact that the ore, as a rule, having a higher specific gravity than 
the gangue cannot so readily escape comminution as the lighter particles 
of rock, and is only discharged from the screen when reduced to a condi- 



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804 PROCESSES OF OBE TBEATME5T. 

tion of comparatively fine palp, while the lighter gangae is expelled when 
much coarser. 

BoasUnq. 

In roasting, the ore undergoes a chemical decomposition, and this 
can frequently be better accomplished if the ore-particles are of fine size. 
The fine condition of the pnlp does not serionsly interfere with the 
subsequent lixiviation, because most ore after a chloridizing-roasting 
(chlorination) becomes sandy, and will filter freely if the gangue is not of 
a clayey nature. In order to convert the silver into chloride, as before 
mentioned, the ore must be roasted with salt ; and to roast success- 
fully, a sufficient percentage of sulphides must be present, as they 
produce by their decomposition sulphuric acid (which acts on the salt and 
liberates the chlorine necessary for the formation of silver chloride). The 
base metals in the ore are converted into oxides, chlorides, and sulphates. 
The requisite amount of salt (depending on the character of the ore) 
varies from 4 to 10 per cent. The salt is either added to the ore before 
it enters tho furnace, or after it has reached a certain stage of oxidizing- 
roasting. The selection of the proper roasting-furnace to employ is a 
matter of great importance : this was proved by Mr. Hofmann in Mexico, 
in experiments made on the San Francisco del Oro ore, in 1888. 

It is to be remarked in favour of the Stetefeldt roasting furnace that 
it requires less salt than any other for chloridizing-roasting sOver ores : the 
decomposition of the salt is very perfect, the chlorine and chlohdizing 
gases emanating from the roasted ore at the bottom of the shaft, acting 
on the falling ore. Ores which are free from lime and magnesia, can be 
chloridized in this furnace with a minimum of salt, and it seems to be 
specially adapted to roasting ores containing copper. Mr. Aaron states 
that at the Surprise Valley mill, California, an average chlorination of 92 
to 98 per cent, was obtained during a nine months* run, roasting silver ores 
of £15 12s. 6d. assay value, with only 2^ to 3 per cent, of salt. Generally, 
5 to 8 per cent, of salt is required in the Stetefeldt furnace, if the ore 
carries lime and magnesia or a larger percentage of base sulphides. The 
chlorination varies with the character of the ore, and the attention with 
which the furnace is managed; results as h^h as 97 per cent, have 
been obtained, while they generally range from 87 to 93 per cent. Ores 
free from sulphur, or with only a slight percentage, should be mixed 
with 1 or 2 per cent, of iron pyrites, otherwise the salt cannot be decom- 
posed. Oxidized ores carrying peroxides of manganese and iron, which 
give off oxygen, can be successfully chloridized by themselves. The best 
results are obtained by mixing oxidized with sulphide ores, more parti- 



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PR0CB88ES OP ORB TREATMENT. 806 

cularly if the former contain peroxide of manganese. The presence of 
copper is very favourable for the chlorination of the silver, and if the ore 
is of such a character that it will bear a high heat without sintering, the 
chloride of copper formed in the upper part of the shaft can be almost 
entirely decomposed, and very fine bullion produced by amalgamation. 
At the Surprise Valley mill, for example, the ore roasted at a low tem- 
perature gave bullion only 300 to 400 fine by amalgamation, the base 
metal being copper. By roasting at a high temperature the bullion was 
almost freed from copper, its average fineness being 980, mtining for nine 
months. All antimonial ores are chloridized with great facility, and 
with a good system of dust-chambers, the loss of silver by roasting is 
hardly perceptible. The same is the case with zinc-blende. In roasting 
ores entirely free from, or with a small percentage of, sulphides, the 
want of sulphuric acid must, as before remarked, be remedied by adding 
another substance. A cheap substitute for pyrites is found in green 
vitriol (sulphate of iron) of which 1^ to 8 per cent, is added when 8 to 10 
per cent, of salt is used. The copper is first calcined to drive off its water 
of crystallization by a gentle heat, and the above percentage of the calcined 
material is taken. The sulphate then acts on the salt as if it were created 
in roasting ; copperas may also be added to arsenical ores free from 
sulphurets. If there is a great deal of lime in the ore, it takes up 
sulphuric acid, forming sulphate of lime, which remains undecomposed ; 
ores containing lime require, therefore, a larger proportion of copperas or 
iron pyrites, sufficient to transform all the Ume into sulphate. At the 
same time, lime assists in decomposing the base metal chlorides in roast- 
ing (5 to 6 per cent, being sometimes added to base ores in a pulverized 
condition), whilst it does not attack the silver chloride ; but too much 
must not l)e added if the ore is to be amalgamated afterwards. The lime 
should be added towards the end of the roasting, introducing 2 per cent. 
to commence with, and well mixing it with the ore. 

Usually, ores containing not more than 8 per cent, of sulphur roast 
well in the Stetefeldt furnace, but in operating on the San Francisco del 
01*0 ore the results turned out unsatisfactory. This ore contained 26'5 
per cent, of zinc, 11*56 per cent, of lead, and 21 per cent, of sulphur, and 
proved too refractory for the Stetefeldt process. The ore (when sifted into 
the furnace) created by the sudden combustion of the sulphides an ex- 
tremely high temperature in the upper portion of the shaft, which caused 
the suspended ore-particles to slag to globules (a coating of silicates being 
formed immediately around them), which prevented their further oxidation 
and chlorination. An analysis showed that 8'48 per cent, of the sulphur, in 

VOL. v.- 160a-98. 20 



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806 PBOGESSER OF ORE TBEA.TMENT. 

fact, remained unozidized. It was found also that a separation of the ore 
took place in the furnace, the shaft receiving the portion carrying most of 
the lead, while the lighter portion, containing most of the iron pyrites, was 
carried over into the descending-flue, where, owing to this circumstance, 
combhied with the high temperature, that particular portion of it was better 
chloridized than the bulk which passed through the shaft. An excess of 
salt lowered the chlorination, and 12 per cent, was found to give the best 
results (60*8 per cent, chlorination) in the descending-flue. Another bad 
feature was the formation of lumps and crusts in the upper region of the 
shaft, and choked the lower side of the feeding-screen. 

An ore of the class operated upon requires to be submitted to a long 
and gradually increasiug temperature before the salt is added ; and as the 
principle of the Stetefeldt furnace is just the reverse of this, the results 
could not but be unsatisfactory. Heavily sulphide ores, especially if they 
carry zinc, require more draught in roasting than lighter sulphide ores ; 
and this is particularly the case when they are exposed for such a short 
time, as in the Stetefeldt furnace, to the action of air and heat. Mr. 
Hofmann^s experiments in roasting the ore of the San Francisco del Oro 
mine in a Stetefeldt furnace go to show : — 

1. An incomplete oxidation of the sulphide minerals, the main 

portion of the ore stUl containing 8*48 per cent, unoxidized 
sulphur when roasted with salt, and 7*6 per cent, when roasted 
without salt. 

2. An insufficient chlorination of the silver. The highest chlorina- 

tion of the ore in the shaft was only 16*9 per cent., and as 62*5 
per cent, of the whole volume dropped into the shaft, the some- 
what higher results obtained in the descending-flue could not 
much improve the average. 

3. That the principle of the Stetefeldt furnace is contrary to the con- 

ditions, the maintenance of which are so essential to roasting 
ores containing much zinc blende and galena. 

4. That, on acount of the sudden exposure of the raw ore-particles 

to such a high temperature, they melt to minute globules, which 
make the ore unfit for further treatment. 

5. That a concentration of the lead minerals takes place in the 

shaft, which is disadvantageous. 

6. That about 25 per cent, of the ore, when passing thi'ough the 

furnace, is changed into hard lumps of almost raw ore. 

7. That the lower side of the feed-screen becomes rapidly encrusted 

and the holes obstructed, requiring frequent changes of screens. 



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PROCESSES OF ORB TREATMENT. 807 

The ore after passing through the shaft of the famaoe had a dark, 
abnost black coloar, and continued to emit volnmes of snlphnrous acid gas 
when discharged, and for some days after, but no chlorine. Mr. Hofmann 
next tried re-roasting the partly roasted ore from the Stetefeldt in a 
modified Howell furnace. Having previously ascertained that this ore 
contained only 1*3 per cent, of salt, 6 to 8 per cent, more was added, and 
the feed regulated so as to put through from 5 to 9 tons per 24 hours. 
The average of thirty-three charges worked thus gave : — average of 
re-roasted ore, 8 1*42 ounces of silver per ton ; average of leach-tailings, 
17*55 ounces per ton ; average of chlorination, 44'2 per cent. 

It is a point to note that the consumption of wood in re-roasting 
proved to be much greater than in roasting raw ore. This is accounted 
for by the main portion of the sulphur, combined with the pyrites, having 
been burnt oflf in the Stetefeldt furnace. During the second roasting, the 
furnace was deprived of the heat of combustion derived from this source, 
so that additional extraneous artificial heat had to be furnished. To 
re-roast in this manner 8'8 tons, it took 26 cargas of wood (12 cargas 
= 1 cord), while it took only 16 cargas to roast 10 to 11 tons of raw 
ore. The roasting capacity of the furnace was also diminished. By 
dumping the red-hot ore from the Stetefeldt direct into a reverberatory 
hearth, the extra consumption of wood during the finishing roasting could 
doubtless have been materially lessened ; but what made this plan imprac- 
ticable was the change the ore underwent in passing through the Stetefeldt 
furnace, which interfered with attempts to obtain a high chlorination 
result afterwards. 

The re-roasted ore was of a red-brown colour, smelled of chlorine and 
did not emit any sulphurous acid gas, but it still consisted principally of 
the little globules, of which mention has been made, quite a large number 
of which remained black, no matter how long the ore was kept in the 
furnace. Some were magnetic, but the majority were not. Between the 
fingers, the re-roasted pulp felt sharp, like powdered glass. The tempera- 
ture was kept at a proper degree, and there was an abundant draught, the 
dust-chambers and furnace having been previously cleared. Still it was 
impossible to obtain more than 44*2 per cent, of chlorination, owing 
undoubtedly to the silicates formed during the roasting in the Stetefeldt 
furnace. A jet of steam* introduced into the reverberatory hearth 
attached to the modified Howell furnace considerably improved the 
results, but still did not give sufficient satisfaction. 

* The introduction of steam through the bridge of the furnace generally increases 
the fuel consumption. 



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308 PBOCB88BS OF OBB TBEATXElTr. 

The average of thirteen charges showed: — average of re-roasted ore, 
81-0 ounces per ton ; average of leach-tailings, 10'37 oonces per ton ; aver- 
age of chlorination, 66*6 per cent. The ore still contained a considerable 
number of globules, but they had changed their colour to red-brown, and 
between the fingers the ore felt soft and not so sharp and glassy as when 
roasted without steam. The Howell furnace alluded to above was not a 
regular Howell, but consisted of a revolving cylinder of uniform diameter 
with a shell of boiler-plate lined with bricks throughout its length (the 
principle on which it works is identical, however, with the Howell furnace), 
and had a reverberatory hearth in front, attached at the end. 

The Howell, like the Stetefeldt furnace, requires the salt to be mixed 
with the ore before entering the furnace. With some ores this is 
immaterial, but it is a matter of the greatest importance for the del Oro 
ore. If the salt is previously added the ore becomes sticky, encrusts the 
furnace rapidly, and leaves the furnace mostly in lumps imperfectly 
chloridized. If the ore is charged without salt it remains dry and sandy, 
but a very annoying separation takes place. The fine particles are carried 
by the draught into the dust chambers, and only the coarse sand passes 
through the furnace without being sufficiently desulphidized. If, then, 
salt be added in the drop-pit, only a small percentage of silver becomes 
chloridized. The best results gave only 29 per cent, of chlorination. In 
order to diminish the separation, 2 per cent, of salt was added to the ore 
in the battery. This small percentage of salt made the ore sticky enough 
to diminish considerably the dusting, without causing the formation of 
lumps or too heavy encrustations. 

By this method, the chlorination improved considerably, the average of 
three days' run being 67 per cent., but Mr. Hofmann convinced himself 
notwithstanding, that the Howell furnace, as such, could not roast the del 
Oro ore. The results were not suflSciently uniform and reliable ; and 
though the roasted ore was left in a good condition, the average could not 
be brought above 67 per cent. An alteration being apparently required, 
which would give the ore more roasting time and allow of a better regula- 
tion of the temperature, Mr. Hofmann made the following changes. In 
front of the furnace, he constnicted a shallow drop-pit and a fireplace, and 
on one side of the drop-pit, communicating with it, he built a small rever- 
beratory hearth, 6 feet by 8 feet, the bottom of both being on the same level. 

The reverberatory hearth contained one working-door and a 24 inches 
fireplace. When enough ore had accumulated in the pit to make a charge 
for the reverberatory hearth, it was pushed in with a hoe, each charge 
consisting of about 1,400 lbs. When starting the furnace, a strong fire 



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PBO0ESSB8 OF ORE TREATMENT. 309 

was kept up in both fireplaces, bnt after the process was in operation the 
fire in front of the cylinder was much lowered ; in fact so much so, that 
half the grate bars remained bare of wood. Only now and then a thin 
stick of wood was added, just enough to prevent the drop-pit getting 
chilled. Two per cent, of salt was added to the ore in the battery. 

If the roasting be properly conducted, the blue flame of the ignited 
pyrites can be observed in the back part of the cylinder. Next to it, and 
reaching beyond the middle of the cylinder, the ore assumes a higher 
temperature, forming a belt of bright red heat. The part of the furnace 
next the fire (nearly one-third of the whole length) should look dark, The 
furnace is mostly heated by the combustion of the sulphides, and receives 
but little supply from the fireplace and reverberatory hearth ; in fact the 
ore in the cylinder should be left as much as possible to roast in its own 
heat. This is a very important condition to maintain, the object being to 
convert as much as possible of the galena and zinc-blende into sulphates 
and oxides before generating chlorine, and to avoid until then as much 
as possible the decomposition of the iron-salts. This can only be done 
by maintaining a low heat after the combustion of the pyrites. 

An excess of heat is invariably connected with an excessive loss of 
silver by volatilization and by a low chlorination. Galena and zinc-blende 
roast quicker and better in a low than a high temperature. When the 
ore leaves the cylinder and drops into the pit, it should be of a dull red 
heat, while the colour after cooling should be dark yellow-brown. If 
the temperature be so kept, neither the odour of chlorine nor much of 
sulphurous acid can be detected. At an increased heat, sulphurous acid 
is again evolved strongly, showing that the oxidation is not yet completed. 
As the temperature in the cylinder is mostly produced by the combustion 
of the sulphides, the chief means of regulating the same is the feed. If 
too much ore enters the furnace, the belt of bright red heat increases, 
advancing more and more towards the front, and finally the whole 
furnace assumes this temperature. The ore dropping into the pit is very 
hot, emits heavy fumes and overheats the pit. If it be then removed into 
the reverberatory hearth, it takes a very long time to finish, necessitating 
an interruption in the feed of the cylinder. 

On the other hand, if insufficient ore be charged, the belt of bright red 
heat gets smaller and moves towards the back end of the furnace. When 
the properly-prepared ore enters the reverberatory hearth, the salt is added 
and the temperature increased. It commences to fume, and swells without 
forming more lumps than an ordinary ore. In the b^inning, strong 
fumes of sulphurous acid are emitted, but soon cease and chlorine appears. 



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310 



PROCESSES OF ORE TREATMENT. 



The charge is finished if the fumes assame a mild and sweetish smell 
of chlorine ; as long as they smell strong, roasting must be continued. 

Mr. Hofmann made a series of experiments to ascertain the smallest 
amount of salt practicable, and found that 4, 6, 8, and 10 per cent, gave 
about equal results ; 12 per cent, commenced to make the ore too sticky 
and produces less chlorination; 3 per cent, was sufficient if the i*oasting were 
very carefully conducted, but then only 1 per cent, had to be added in the 
battery and 2 per cent, in the furnace ; 4 per cent., however, was safer, for 
then the result did not depend so much on the skill and goodwill of the 
labourers. The roasting capacity of the furnace proved much less for 
the del Oro than for ordinary ore. The cylinder was only 24 feet long, 
which could not roast more than 8 J tons per 24 hours ; but even with a 
82 feet cylinder, Mr. Hofmann states he did not expect to roast more 
than 12 tons per day. 

Each charge had to remain 2 hours on the reverberatory hearth. 
Though the ore was roasted in the reverberatory hearth at a somewhat 
increased heat, it could not be raised beyond duU red without losing too 
much silver by volatilization. 

If the silver-bearing minerals of an ore be not of great density and 
decrepitate in the heat, the ore can be crushed coarse without endangering 
the subsequent roasting, but if the principal silver-bearing mineral, like 
the zinc-blende in the del Oro ore, be of great density and does not 
decrepitate, it is of the greatest importance to crush fine. 

A series of experiments was made by Mr. Hofmann with ore crushed 
through No. 20 and No. 40 screens. He found that the ore crushed 
through No. 20, required a much longer time and was 27 per cent, less 
chloridized than the ore crushed through No. 40 screen. The material 
which passes through a battery-screen of a certain number, is much finer 
than the size of the meshes. Heavy ore makes a much finer pulp 
through the same screen than lighter ore. The pulp of the del Oro ore 
obtained by crushing through battery-screens Nos. 20 and 40, when 
sieved through sieves of different fineness, showed the following 
results: — 



Battery Pulp 

when Hifted 

through Sieve. 

30 
40 
60 
60 
90 



Crushed through 
Battery Screen 

No. ao. Peroent- 
age of Material 

paifliug through 
the Sieve. 

93-8 
87-3 
78-8 
71-2 
671 



Crushed throogh 
Battery Screen 

No. 40. Percent- 
age of Material 

passfng through 
the 8ieT& 

100 
100 

98-95 

93-80 

90-50 



Gnuhed through 
Battery Screen 
No. 29. Percent- 
age of Material 
remaining on 
the Sieve. 

6-2 
12-7 
21-2 
28-7 
32-9 



Oruflhed through 
Battery Screen 
No. 40. Percent- 
age of Material 
remaining on 
the Sieve. 

0-0 

0-0 

1-06 

6-20 

9-60 



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PROCESSES OF ORB TREATMENT. 811 

These figures show how exceedingly fine a heavy ore is crushed (dry) in a 
battery, even through a screen with comparatively coarse meshes. Though 
67" 1 per cent, of the material crushed through screen No. 20 was finer 
than sieve No. 90, the average chlorination of quite a number of compara- 
tive roastings was 27 per cent, less than that of ore crushed through a 
No. 40 screen. This indicates how essential it is to crush such ores fine. 

Mr. Hofmann found that in order to chloridize the del Oro ore well, 
it had to be crushed through a No. 40 battery-screen, which furnished 
a pulp of which only 9^ per cent, was coarser than sieve No. 90. To 
produce such a fine pulp with rolls, would require such exceedingly fine 
screens that their use would be here impracticable. The crushing capacity 
of the battery was not much diminished by using No. 40 screen instead of 
No. 20, principally because the ore was so heavy. 

For comparison, Mr. Hofmann ran 5 stamps, 12 hours, crushing 
through No. 20, and 5 stamps through No. 40, and found : — 

No. Lbfl. of Pulp. 

20 with salt famished 8,100 

40 with 4 per cent, salt furnished ... 7,488 

Difference in fayour of No. 20 screen 612 Ibe., or 7^^ per cent. 

A very small reduction, if the great advantage gained for roasting is 
considered. Some ores gain much in chlorination of the silver, if left hot 
in a pile for several hours; this is mostly the case when an ore is 
insufficiently roasted, or when the nature of an ore is such as to reqnire 
long roasting at low heat. 

Additional chlorination can be produced by moistening the ore and 
leaving it for several hours in the pile ; this is usually the case if the ore 
contains copper. Roasted ore containing caustic lime should not be left 
moist on the cooling-floor, hence the del Oro ore could not be wetted on 
the cooling-floor without decomposing some of the silver chloride. Mr. 
Hofmann remarks that the most important additional chlorination takes 
place, however, during base-metal leaching. 

In the Silver King ore, Arizona, this additional chlorination amounted 
to nearly 6 per cent. Mr. Hofmann therefore filled the Vat before charging 
about one-third with water and dumped the ore hot into it, thus producing 
a hot base-metal solution, and made the observation that by it not only 
the decomposition of the silver chloride was avoided, but that a considerable 
increase in the silver chlorination took place, amounting in some 
instances to 12*9 per cent. If the original chlorination was 75 per cent, 
or more the increase was, however, much less. By adding some oupric 
chloride to the water in the vat before dumping in the ore, badly roasted 



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^12 PBOGESSBS OF ORE TBEATMEin'. 

charges gained as mnch as 84 to 88 per cent, (see charges, Nos. 9, 15, 
and 16 in annexed table). These are very important obeervations, and 
give the operator a means of correcting badly roasted charges. 

The following table is a carefnl record of the • results obtained in 
roasting the San Francisco del Oro ore in the Howell furnace modified by 
Mr. Hofmann, representing a two weeks' run. As each tank-charge con- 
tained the whole ore of 24 hours' roasting it offered a good opportunity of 
following each charge through the process from the condition of raw ore 
to tailings, and of ascertaining for each the loss by volatilization, etc. 

Taking the average of the results we find the silver chlorination when 
the ore left the furnace was 68*4 per cent.; the additional chlorination was 
13'8 per cent.; or a total of 81*7 per cent. The low average chlorination 
of the ore when leaving the furnace, was caused by the three badly-roasted 
charges 9, 15, and 16. The other eleven charges gave an average of 
about 75 per cent. 

Mr. Hofmann remarks — "The total or actual chlorination of 81*7 per 
cent, may seem to be low, but if we consider that the ore is of low grade, 
averaging only 28*85 ounces per ton, and that 1 per cent, represents only 
0'28 ounce of silver, and also consider that the ore contains about 87 per 
cent, of zinc-blende, and 13 to 19 J per cent, of galena, which carry all 
the silver, and that the ore was pronounced as being too refractory for 
chloridizing-roasting, we have to count the work done by the modified 
Howell furnace, as very satisfactory." 

In order to ascertain the loss of silver by volatilization we have first 
to ascertain the loss in weight which the ore sustains during roasting. 
This can be done by the muffle test described by Mr. Hofmann in The 
Enginemmj and Minimj Journal^ New York, of April 23rd, 1887.* "Ten 
grammes of the raw pulp containing salt are placed in a roasting dish 
and roasted in the muffle for half an hour or an hour, then the sample 
is removed from the muffle, allowed to cool, weighed, placed back in the 
muffle, and roasted again for half an hour, then weighed again. This is 
repeated till two weighings are alike, or till in the last half hour of 
roasting, the ore does not lose more than 2 or 8 milligrames. The differ- 
ence between the original weight and that of the last weight expressed in 
percentage gives the highest possible loss which the raw ore can sustain." 

Ten grammes of a sample of roasted ore corresponding with the sample 
of raw pulp are placed in a roasting dish, and also roasted in the muffle 
until two weighings agree or differ after half an hour's additional roasting 
not more than 2 or 3 milligrammes. The difference between the first 
weighing and the last (expressed in percentage) gives the weight which the 

• Page 293. 



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PB00BSSE8 OF ORE TREATMENT. 



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Digitized by VjOOQ IC 



314 PROCESSES OF ORE TREATMENT. 

roasted ore is still capable of losing if subjected to prolonged roasting. 
If we dednct this last loss from the highest possible loss, we obtain in per- 
centage the loss in weight by volatilization which the ore has suffered 
during roasting in the furnace. 

Owing to a great part of the lead and zinc sulphides being converted 
into sulphate, the San Francisco del Oro ores lose but a small percentage 
of their weight during roasting. The tests showed a loss of 2^ to 3^ per 
cent. With these figures and the assay value of the raw and roasted ore, 
the loss of silver by volatilization was calculated. The extremes were 1*7 
and 15*5 per cent., and the table illustrates how variable this loss is. 
Mr. Hofmann says he found the del Oro ore more sensitively disposed for 
such losses than many others, even antimonial ores. The least increase of 
temperature above dull red causes a heavy loss, even if this increase of 
temperature lasts only for a very short time. Two or three thin sticks of 
wood thrown on the fire before they are needed may materially increase 
the loss. The loss by volatilization is not in direct proportion to the 
percentage of chloridized silver. In proof of this Mr. Hofmann instances 
the results of roasting Las Yedras ore at high and low temperatures in 
Bruckner furnaces : — 

High temperature, averages of 31 consecutive working-days, January 
13th to February 12th, 1887. 





Funuuw No. 3. 
Par Cent. 


FaraaoeNo. 4. 
Per Gent 


Arenwe of both 
FnrnnoeB. 
Percent. 


Chlorination 


71-3 


74-2 


72-7 


Loss by volatilization 


18-3 


17-6 


17-9 



Low temperature, averages of 30 consecutive days, June 1st to July 
1st, 1887. 

Average of both 
Famaoe No. 3. FomMe No. 4. Fumaoee. 

Per Gent. Per Oent. Per Cent. 

Chlorination 81*7 ... 81-8 ... 81*5 

Loe8 by volatilization ... 1-7 ... 0*7 ... 1*2 

By comparing these average results we find an increase of Per oeDt 

chlorination, in favour of low heat, of 8*8 

A decrease of loss by volatilization caused by low heat ... 16*7 

Total increase of production 25'6 

The roasted ore contained only a small percentage of lumps, not hard, 
but porous, which fall to powder if kept in contact with water for some 
time. If the ore be left dry in a pile, it hardens. If left undisturbed for 
a week or two, it becomes so hard HbaJb a pick is necessary to loosen it. In 
water, however, it softens easily again. The colour is usually red-brown. 



Digitized by VjOOQ IC 



PR00B8SES OF ORE TREATKENT. 815 

bat occasionallj, if the ore contain less iron pyriteB, it is yellow-brown. 
The heavy metals in the Yedras ore are principally converted into snl- 
phates, and only a small proportion are present as chlorides. 

The following is an analysis of the unassorted ore after roasting with 
5 per cent, of salt : — Gold, traces ; silver, 0'09 per cent. ; lead, 9*00 per 
cent.; iron, 6 '00 per cent. ; zinc, 22'46 per cent. ; caustic lime, 5*65 per 
cent. ; antimony, 075 per cent. ; copper, 0*60 per cent. ; cadmium, 0*10 
per cent. ; alumina, 3*09 per cent. ; caustic soda, 3*79 per cent. ; sulphuric 
acid, 18'16 per cent.; chlorine, 0*88 per cent.; soluble silica, 8*00 per 
cent. ; and insoluble gangue, 18*61 per cent. 

Mr. Hofmann mentions an easy method of removing crusts from con- 
tinuous discharging-furnaces, which can be done while the furnace is in 
operation. In the masonry at the back an opening is made, so located 
that with a long iron spade the interior of the cylinder can be reached 
just below the feed-pipe. Through this opening, 1^ dozen firebricks are 
introduced while the cylinder is revolving, and in moving slowly forward 
shove off the crust clean down to the lining. The crust when hot is soft 
and yields to the weight of the moving bricks. It is not necessary to 
interrupt the feeding. If bricks should be found too light, heavier, but 
not too large, pieces of castings may answer. 

Owing to the large quantity of sulphides in the ore and the very 
low temperature at which the del Oro has to be roasted, the consump- 
tion of wood is very small. After the furnace is heated and the cylinder 
encrusted, it takes hardly any fire in front of the cylinder to maintain 
the proper temperature. In the reverberatory a little more fire is needed, 
but much less than with ordinary ores. Mr. Hofmann states that he 
weighed the wood during a couple of weeks, and found the total consump- 
tion during this period to be 220 cargas (at 300 lbs.). With this 
quantity of wood he roasted 115'8 tons, and therefore used 1*8 cargas per 
ton. 12 cargas of Parral wood being equal to 1 cord; if we express the 
consumption in cords, we find that with 1 cord of wood the furnace 
roasted 6*3 tons of ore. The cost of roasting in the modified Howell 
furnace (roasting 8^ tons per 24 hours) is as follows : — 

DoUan. 

2 beacl roasters at $1*50 3*00 

4 helpers at 90 cents 3*60 

4 per cent, salt, 680 lbs. at 1*27 cents ... 8'63 

16*7 cargas wood at 75 cents 11*77 

Steam-power, 10 cargas of wood at 75 cents 7*50 

Oil, light, tools, etc 2*00 

Management, oiEce, mechanic, assay office 1*78 

Total 38*28 

And the cost per ton, $4*50, Mexican currency. 



Digitized by VjOOQ IC 



816 PROCESSES OF ORE TKEATMENT. 

To ascertain the cost of steam-power a separate boiler was used for the 
furnace. It is evident that by using a boiler for only one small furnace, 
the expense per ton of ore will be much greater than if with the same 
boiler and engine several large furnaces are operated, but this was the 
only way of getting an estimate. 

The steam for working the pump and preparing the calcium sulphide 
were supplied by the same boiler and had to be charged to roasting. It is 
included in the above statement, and wiU therefore not appear in the 
statement of cost of Uxiviation. 

As the statement of cost is made for only 8^ tons per day, it would be 
misleading if the whole expense for management, mechanics, assay office, 
etc., were charged to the 8^ tons, as these expenses would remain the same 
for 100 tons a day — ^the intended capacity of the new mill. The proportion 
chargeable on 8^ tons, treating 100 tons per day, has therefore been debited 
to this item, but as there are three departments in the mill, viz., stamping, 
roasting, and leaching, each department has to be charged with one-third 
of this expense ; 1'78 dollars represent therefore one-third of the cost. 

The figures contained in the preceding table are the results of experi- 
ments obtained with different treatment as regards salt, temperature, 
time, etc., and the averages do not therefore represent the best obtainable 
results. This is e^)ecially the case in regard to loss by volatilization, 
which should be reduced as the men gain experience in handling the 
furnaces. They were good enough, however, to secure a profitable 
reduction of the ore, and may be accepted as a basis for calculations and 
estimates. 

In order to increase the roasting capacity to the stamping power of the 
mill and for the sake of further experiments, Mr. Hofmann erected four 
double-hearth reverberatory furnaces (the lower hearth of 220 square feet 
surface, and the upper of 210 square feet surface) to supplement the 
modified Howell furnace. 

Bach double furnace took four charges of 1 ton each ; when one charge 
was finished, aU the others were moved forward, and on the first hearth 
a new charge dropped through the opening in the arch. From the second 
hearth the charge was dropped on the lower hearth, through an opening in 
the bottom near the working-door. The upper hearth was exclusively 
used for oxidizing-roasting, and 4 per cent, of salt was added while 
the charge was dropped on to the lower hearth. Every 2^ to 8 hours a 
charge was done, and therefore each double furnace roasted from 8 to 10 
tons per day, according to the quantity of lead the ore contained. The 
chlorination results were so near those obtained in the modified Howell 



Digitized by VjOOQ IC 



PROCESSES OF ORE TREATMENT. 817 

furnace that it is not neceaaaty to give details, but Mr. Hofmann records the 
obeervations he made on a charge snbiaitted to a prolonged oxidizing- 
roasting. They are too long to be given here, but will be found fully 
described in Th$ Engineering and Mining Journal^ New York, of February 
23rd, 1889.^ 

He found that the ore during oxidizing-roasting sustained a loss of 
silver by volatilization of not less than 13 per cent, (not taking into 
calculation the loss in weight), and that this loss principally occurred 
during the seventh hour, at the time the ore assumed a dark red-brown 
colour. 

Only a part of the soluble silver, he concludes, was present as sulphate, 
viz., 25'2 per cent. Of the 68"8 per cent, which was soluble, 33'6 per 
cent, was some other silver salt, not soluble in water, but soluble in sodium 
hyposulphite, probably silver antimoniate. 

The reverberatory furnaces were built in pairs, two being connected 
with one main flue. 

During four weeks the wood consumed by one pair of these furnaces 
was weighed. In this time 507 tons of ore were roasted at a consumption 
of 672 cargas of wood, or 1*8 cargas per ton. If expressed in cords, 
we find that one cord of wood roasted 9 tons of ore, an extremely small 
consumption. 

The cost of roasting in the reverberatory furnace, for two double- 
hearth furnaces roasting 18 tons per day, was as follows : — 

DoiUn. 

2 head roasters at $1*50 300 

16 roasters at $100 16-00 

2 wood carriers and ore wheelers at 90 cents 1*80 

2 carmen for raw ore chargers at 90 cents 1*80 

23'4 cargas of wood at 76 cents 17"55 

4 per cent, salt, 1,440 lbs. at |l-27 ... 1828 

Tools, etc 4-00 

Management, office, mechanics, assays ... 3-77 



Total G620 

And the cost per ton, 67 cent«, Mexican currency. 

To form an opinion as to which roasting-furnace is the most suitable 
for an ore like the San Francisco del Oro, we have to take into considera- 
tion only the modified Howell and the reverberatory furnaces. The 
Stetefeldt furnace did not answer, and the Bruckner furnace was not 
tried, as experience has shown that a large Bruckner furnace could not 
roast more than 5 or 6 tons of such a heavy ore. Both the modified 

• Page 190. 



Digitized by VjOOQ IC 



818 PRO0B88BS OP ORB TREATMENT. 

Howell and the reverberatoiy f nrnace gave abont the same results, and 
the loss by volatilization was also nearly the same. The cost, however, 
was different, viz., 4*50 dollars per ton in the former, and 3'67 dollars 
in the latter, being a difference in favour of the reverberatory furnace of 
83 cents per ton. 

This ought to decide ; still there are, besides the merits of the furnace, 
other circumstances to be taken into consideration. The reverberatory fur- 
nace requires quite a number of skilled hands, and the result depends much 
more on the skill and goodwill of the men, than with the modified Howell. 
Mexicans are, as a rule, if properly handled, very good workmen, notwith- 
standing that they receive such moderate wages, but they like to lay off 
on Sundays and feast days. On such days quite a number of inexperienced 
substitutes will be found working at the furnaces, and the roastings 
consequently suffer. The main trouble, however, occurs every year in 
spring and autumn, the time of planting and harvesting com, when many 
leave the camp, and the mill is left short of hands. For this reason it 
may be more advisable in a large mill to use the modified Howell furnace, 
notwithstanding that the reverberatory furnace works cheaper and creates 
much less flue-dust. The Howell inmaoe forms a great deal of flue-dust, 
which is far from being roasted even if the furnace be provided with an 
auxiliary fireplace, as in the Howell- White furnace. 

LiXIVIATION. 

Base-metal Leaching, — The roasted ore is moistened with water and 
charged into wooden vats, in charges of 10 to 15 tons, though much larger 
charges are sometimes worked. The vats are best furnished with a central 
discharge, around which a filter-bottom is arranged in the shape of a very 
flat ftinnel. The filter-cloth is kept in place by ropes driven into grooves 
around the discharge-hole and inner periphery of the tub, near the filter- 
bottom. The vat is provided with an outlet under the filter, and has a 
slight inclination towards this point. 

The charge of roasted ore is leached with water to remove the soluble 
base-metal salts. Water does not dissolve silver chloride, but a concen- 
trated solution of base-metal chlorides does, and it is therefore advisable 
not to make the leaching- vats too deep, as otherwise a too concentrated 
base-metal solution is produced by the water in descending through a 
thick layer of ore. The base- metal leaching is completed when a few drops 
of calcium polysulphide poured into some of the outflowing solution does 
not produce a precipitate. This part of the process, according to the 
character of the ore, takes 4, 8, or 10 hours. 



Digitized by VjOOQ IC 



PROOBSSBS OF ORE TREATMENT. 819 

With the San Francisco del Oro ore, which filters well, the rate of 
filtration dnring base-metal leaching was 1 inch in 6 minutes or 10 inches 
per hour. With a vat 10 feet 2 inches in diameter, representing a 
filtering surface of Sl'Ol square feet, and a thickness of charge of 2*41 
feet, the above rate was equivalent to 67*24 cubic feet, or 504*8 gallons 
per hour ; leaching time, 8 hours = 4,084*4 gallons ; 2 feet of water in the 
vat into which the ore is dumped = 1,215-2 gallons extra. Second wash- 
ing, rate of filtration, 8f inches per hour ; time, ij hours = 647'1 gallons. 
Total for one chaise of 8*89 tons, 5,896*7 gallons, or 708 gallons for each 
ton of ore. It has been mentioned that, on account of the roasted ore con- 
taining considerable caustic lime, it was not moistened as usual on the 
cooling-floor but dumped dry and hot into about 2 feet of water in the vat. 
Besides other advantages, this way of charging shoi^tens the base-metal 
leaching time by nearly an hour, without reducing the rate of filtration. 
When the charge is in, the water ought to cover the ore about 1 inch. 
Leaching is then commenced from below,* and the solution diluted above. 
As soon as the solution lb allowed to flow out below, a stream of clear 
water has to be turned on above and continued for about an hour, in order 
to produce a greater dilution. Then the influx is interrupted until the 
water sinks to the level of the ore, when water is again allowed to flow in. 
The base-metal solution of the del Oro ore shows an acid reaction. The 
leaching with water is continued until a few drops of calcium sulphide 
added to the solution produces only faint white clouds. These white 
clouds continue to show for hours, and are caused by the reaction of 
calcium sulphide and sodium sulphate precipitating gypsum. It takes a 
long time to leach alkaline salts contained in porous substances, thus it 
happens that while all the soluble metal salts have been dissolved and 
removed, the outflowing solution still contains and continues to contain 
sodium sulphate. 

Prom a chemical standpoint, it would be advisable to continue leaching 
with water till all the sodium sulphate is removed, but in practice this would 
delay the process too much, and the silver leaching is therefore commenced 
as soon as all the heavy metal salts ai-e removed. The sodium sulphate 
which still remains in the ore after leaching with water, enters the stock 
solution during the subsequent silver leaching. This has not a very 
injurious effect if calcium sulphide is used as a precipitant, because sodium 
sulphate is decomposed and gypsum precipitated. 

The stock solution is therefore freed from sodium sulphate after every 

• This is done to precipitate on to, and through the ore any chloride of silver 
that might be dissolved by a too concentrated solution of the base-metal chlorides. 



Digitized by VjOOQ IC 



Silver ... 


0M)036 


Cwlminm 


0-806 


Zinc ... 


2-105 


Iron 


0-008 


Copper... 


Trace 



820 PROCESSES OF ORB TREATMENT. 

precipitation, and the only resulting disadvantage wiU be that the 
precipitate will contain more gjpsnm. But if sodium sulphide is used as 
a precipitant, the effect of the sodium sulphate is very injurious, as it 
remains and accumulates in the stock solution and soon reduces its 
dissolving energy for silver chloride, rendering a iwt)longed leaching with 
water necessary. By inserting, in the outlet of the vat, a small rubber 
tube (provided at the end with a glass tube drawn to a fine point), and by 
leaving this tube in the outlet during the whole time of biise-metal 
leaching, Mr. Hofmann obtained from the outflowing solution a very fine 
stream which, collected in a proper vessel, gave a true sample of the 
solution of about 3 or 4 gallons. This sample contained in 1,000 cubic 
centimetres : — 

Grammes. 

Lea<l — 

Sulphuric acid ... 18-708 

Chlorine 7-173 

Lime 0754 

Silvf^r Learhifig. — The base-metal salts being removed, a stream of 
diluted solution of sodium hyposulphite is allowed to enter on top of the 
ore, which readily dissolves the silver cliloride. When the outflowing 
solution shows indications of silver, the strcam is conveyed to special 
precipitating-tanks, in which the silver is precipitated as silver sulphide 
by an addition of calcium polysulphide or some other reagent. 

To ascertain the exact time when the hyposulphite solution, which 
follows the water, commences to appear at che outlet, a matter of import- 
ance, it is ordinarily tested with calcium polysulphide, and some operators 
indulge in the bad habit of testing it with the tongue, and are guided by 
the sweetish taste which the solution has if it contains silver. The follow- 
ing test is much superior, and is very sensitive and convenient : — A small 
strip of starch paper is dip]xjd into a solution of iodine and then held in 
the outflowing stream. If the blue colour disappeai-s it is a sign that the 
liquid contains a hy|)osulphite salt, and the stream must be turned into 
the precipitation- vats. The test is only applicable, however, when the 
base-metals are leached with cold water, as hot water discolours the blue 
paper. To facilitate and hasten the settling of the silver precipitates, the 
precipitation-tanks are provided with machine stingers, by which the 
solution can be vigorously agitated. 

After precipitiitiou, the sodium hyposulphite solution is decanted 
after the precipitate has settled in tanks pLaced at a lower level. 
From these tanks the clear solution is pumped up to storage-tanks and 



Digitized by VjOOQ IC 



PROCESSBS OF ORB TRBATMBNT. 821 

is ready to be used again. When all the soluble silver is extracted, the 
solution of the hyposulphite is allowed to run out till it disappears under 
the surface of the ore, when clear water is introduced again to displace all 
the hyposulphite solution ; after this second leaching with water, the tail- 
ings are sluiced out through the central discharge, and the tank is ready 
for another charge of ore. The time for silver leaching varies according 
to the character of the ore from 8 hours to 2 or 8 days. 

In the ordinary lixiviation process, calcium sulphide is the ordinary 
and best precipitant. This salt, however, cannot be used for that purpose 
in the Russel process, and sodium sulphide therefore takes its place. In 
the Eass process the ore is leached with calcium hyposulphite, and the 
silver is precipitated with calcium sulphide. Leaching with sodium 
hyposulphite and precipitating with calcium sulphide (the ordinary 
method) is really a combination of the Patera and Eass processes. When 
enough silver precipitate has accumulated on the bottom of the precipi- 
tating-tanks, it is drawn off and generally strained through a filter-press. 
The black sQver cakes are then taken out, dried in a warm room or drying- 
oven, and introduced into a muffle or calcining-fomace to burn off the 
sulphur. After the blue flame has disappeared, heating must continue for 
several hours at a dark red heat. 

The roasted cakes may be melted with lead in a cupelling-f urnace, and 
refined or melted in graphite crucibles, in lots up to 300 lbs. in weight. 
What sulphur remains must be removed by melting it off with metallic 
iron introduced into the pot, an iron matte being formed, which rises to 
the surface and is skimmed off. The surface of the silver is then cleaned 
by adding some bone ash and borax, or borax alone, which is also skimmed 
off, and the silver dipped out or poured into moulds. 

The quantity of hyposulphite solution required for treating the San 
Francisco del Oro ore is as follows : — The diameter of the vat is the same 
as for base-metal leaching (previously described), viz., 10 feet 2 inches. 
Rate of filtration, 8§ inches per hour or 57"52 cubic feet or 431-4 gallons 
per hour. Time of silver leaching, 4 days or 96 hours or 41*414 gallons 
per charge of 8'39 tons, or 4,935 gallons for each ton of ore, 658 cubic 
feet. 

At the Cusi mill, Mr. Hofmann states the vats are 12 feet in diameter, 
taking a charge of about 8 tons of ore. At a filtering rate of 8 inches 
per hour the volume of outflowing solution amounts to 74*6 cubic feet per 
hour, or 8,058*6 cubic feet in 41 hours for a charge of 8 tons, or 382*3 
cubic feet or 2,867 gallons per ton of ore, employing the Russel process, 
taking the figures given by Mr. Stetefeldt. Mr. Hofmann, however, states 

VOL. V.-18W.98. 21 



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322 PROCBSSBS OF ORE TREATMENT. 

that he found the average leachiDg time at the Cusi miU to be 53 hours, 
which at the filtering rate of 8 inches per hour gives 494*2 cubic feet or 
8,706 gallons per ton of ore. 

The Stock Solution. 

Mr. Hofmann appears to have been the first to introduce the practice 
of using sodium hyposulphite as a solvent and calcium sulphide as 
a precipitant. Calcium sulphide contains a considerable amount of 
(about 6 per cent.) calcium hyposulphite, even if freshly prepared, which 
in precipitating is introduced into the stock solution. It was therefore 
supposed that by using calcium sulphide as a precipitant the stock 
solution would be gradually converted into a solution of calcium hypo- 
sulphite, but Mr. Hofmann denies that this is the case, and states that 
the stock solution remains as sodium hyposulphite. He explains it in 
this way : At the time when base-metal leaching is usually interrupted, 
the ore stQl contains sodium sulphate. Calcium hyposulphite and 
sodium sulphate form sodium hyposulphite and calcium sulphate, which 
precipitates 

CaSjOs + Na,S04 = CaS04 + Na,8A. 

If therefore the stock solution after precipitation, containing calcium 
hyposulphite, is rinsed, and comes in contact with the sodium sulphate 
contained in the roasted ore, the outflowing solution will have its calcium 
hyposulphite substituted by sodium hyposulphite, leaving the precipitated 
gypsum in the ore. 

Thus the stock solution, even after continued use, still consists of 
sodium hyposulphite. It takes longer boiling to manufacture calcium 
sulphide than to prepare sodium sulphide, but 8^ to 4 hours' boiling is 
sufficient, and the consumption of steam is small to maintain the solution, 
once it is boiling, at that temperature. The calcium sulphide appears to 
have the great advantage that it frees the stock solution from the very 
injurious presence of sodium sulphate, for if calcium sulphide is brought 
in contact with sodium sulphate, sodium sulphide is formed, which goes 
into solution, and the calcium sulphate is precipitated ; thus all the sodium 
sulphate which the stock solution receives from the ore during lixiviation 
is decomposed, while sodium sulphide if used as a precipitant not only 
leaves the sodium sulphate undecomposed, but even furnishes an addi- 
tional supply of this salt, and assists in charging the stock solution with 
it, diminishing its dissolving energy for silver chloride, and causing quite 
a large consumption of sodium hyposulphite. 

If in preparing calcium sulphide, boiling is not continued beyond 
8 or 4 hours and precipitation is properly executed, the original stock 



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PROCESSES OF OBS TREATMENT. 823 

solution can be maintained effective for several years without adding any 
fresh sodium hyposulphite to it. It will be even found that the solution 
increases in strength, and in order to keep it at standard strength it 
requires to be diluted from time to time with water. This cannot be 
accomplished if sodium sulphide be used. The loss of hyposulphite by 
decomposition and other causes is in fact more than replaced by the 
supply derived from the precipitant. 

Mr. Hofmann gives a table* showing the tendency of the sodium hypo- 
sulphite solution to increase in strength, as above explained, and remarks 
that it is quite an important financial item whether its standard strength 
(0*50 per cent.) is kept up by adding water or sodium hyposulphite. At 
the Cusi mill, he used 765 lbs. of sodium hyposulphite for the preparation 
of the stock solution, working with it 2,011 tons of ore, and left the 
solution in perfectly good condition, only a little stronger than when 
originally prepared, without adding any extra sodium hyposulphite, while 
Mr. Daggett, who used sodium sulphide, reports a consumption in the 
Cusi mill of 3 to 7 lbs. of sodium hyposulphite per ton of ore. 

Mr. Hofmann states that in working 2,011 tons of Cusi ore containing 
45*2 ounces of silver per ton, the cost of calcium sulphide per ton of ore 
was as follows : — 

Sulphur, 3-92 lbs. at 7 cents 27-4 

Lime, 8*25 lbs. at 1 cent 8*2 

Total 86-6 

or 28*7 cents less than the cost of sodium sulphide (reckoned at 64*3 
cents) treating an ore containing 35*1 ounces of silver. Reducing the 
above figures to what they would be in working an ore containing 35*1 
ounces of silver per ton, they would stand : — 

Cento. 

Sulphur, 8*02 lbs. at 7 cents 2M 

Lime, 6*40 lbs. at 1 cent 6'4 

Total 276 

or 86'8 cents less than the cost of sodium sulphide, which is equal to 
a saving of 57*2 per cent. Taking into consideration the fact that the use 
of sodium sulphide causes also a consumption of 8 to 7 lbs. of sodium 
hyposulphite per ton of ore, it is apparent that sodium sulphide is more 
expensive, and that calcium sulphide is preferable as a precipitant, regard- 
less of other advantages, for the important reason that it keeps the stock 
solution free from sodium sulphate. 

♦ The Engineering and Mining Journal, New York, vol. xlvii., page 236. 



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824 



PROCESSES OF ORE TREATKBKT. 



The calcinm polysulphide is manufactured at the works, by boiling 2 
parts of the fresh lime with 1 part of pulverized sulj^ur in water for 3 to 
4 hours, in deep tanks made of boiler iron, into which steam is directly 
introduced. The consumption of sulphur ia from 2 to 7 lbs. per ton 
according to the ore. 

The Precipitate. 

Mr. Hoftnann gives the analysis of two different lots of roasted 
precipitate of del Oro ore : — 





PerOenl 


PerOent. 




PerCcDt. 


Percent. 


Gold ... 


004 


0-014 


Zinc ... 


4-30 


13-86 


Silver ... 


1900 


21-60 


Lime ... 


8-88 


3-62 


Lead ... 


30-64 


2110 


Salpfa. acid 


6-10 


618 


Copper 


11-65 


4-44 


Sulphur 


14-90 


19-87 


Cadmium 


8-45 


1-20 


Insoluble 


5-46 


4-96 


Iron ... 


0-72 


2-68 









The two lots of precipitate differ, as will be seen, considerably with regard 
to lead, copper, cadmium, zinc, and sulphur, due partly to variations in the 
character of the ore, of which the precipitate is the resulting product, and 
to a great extent to variations in roasting. 

The quantity of sulphur depends on the length of time the precipitate 
is subjected to roasting in the reverberatoiy fnmace. To avoid loss by 
volatilization, the precipitate was left in the furnace only until the blue 
sulphur flame ceased. The percentage of lime (8*88 to 8'62) is in both 
lots nearly the same, and shows that the value of the precipitate is not 
depreciated, by using calcium sulphide as a precipitant, enough to make 
its use objectionable. The dried precipitate contains 47'96 per cent, of 
sulphur. Experiments to regain the surplus sulphur by boiling the fresh 
precipitate with caustic soda gave very satisfectoty results. They showed 
that 60 per cent, of the sulphur originally contained in the precipitate 
can be thus regained and bi-ought into a state in which it can be directly 
used again as a precipitant. 

Using Cupric Chloride for Badly-roasted Charges, 

If an insufficiently chloridized ore be treated during base-metal leaching 
with a dilute solution of cupric chloride it has a very beneficial effect, as 
stated elsewhere, and Mr. Hof mann, in some instances, obtained a further 
extraction from the del Oro ore of 34 to 40 per cent, of the silver by its 
use. 35 lbs. of bluestone and about 70 lbs. of salt, boiled by steam for 



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PROCESSES OF ORE TREATMENT. 825 

about 15 or 20 minutes, gave a sufficient quantity of cupric chloride for 
a charge of 8^ tons, at a cost of 60 cents per ton of ore : — 

DoUan. 
Bluestone, 35 lbs. at 12 cents ... 4*20 
Salt, 70 Ibe. at 1-7 cents 0-88 

Total 6-08, or 0-60 cents per ton. 

The cupric chloride is either added to the water contained in the tank, 
into which the dry and hot ore is dumped, or it is added during base- 
metal leaching. In the latter case it is better to apply the copper solution 
after the main portion of the base-metal salts have been leached out, say 
about 1 hour after commencing base-metal leaching, and to add it gradually 
in order to penetrate the whole charge. To about 6 or 8 inches of water 
standing above the ore, one quarter of the prepared copper solution is 
added, stirred, and allowed to sink through the ore. As soon as the 
liquid is level with the top of the ore, the outlet under the filter is closed, 
and again 6 or 8 inches of water is allowed to flow into the vat, to which 
the second quarter of the copper solution is added; this is repeated a third 
and fourth time, and the charge is washed in the usual way. 

The first method is quicker and less troublesome, but in this case 
leaching from below is advisable. The solution from the del Oro ore 
treated in this way left the tank colourless with only a slight reaction for 
copper, showing that the cupric chloride was decomposed in passing 
through the ore. Mr. Hofmann believes that if the roasted ore of the 
Yedras mine were treated in this way, very good results would be obtained, 
without reducing the fineness of the precipitate as much as is done at 
present by the use of extra solution. 

Cost of Lixiviation. 

The works at Parral have two leaching-plants, one in connexion with 
the modified Howell furnace and the other with the reverberatory furnaces. 
Separate accounts were kept of each. The following figures refer to the 
Howell plant. For the consumption of sulphur no separate account could 
be kept, and the quantity used per ton is therefore calculated on the total 
amount consumed and the total number of tons of ore leached in both 
mills. It gives a consumption of 7 lbs. per ton of ore. One man was 
employed roasting the precipitate obtained from both plants, and one-half 
of his wages is charged in the statement. A reduction of cost, it is stated, 
could be effected if the precipitate were boiled with caustic soda, instead of 
roasting it. The item of management, office, etc., represents one-third 



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326 PROCESSES OF ORE TREATMENT. 

of the cost for 100 tons per day, calculated proportionately on 8^ tons, as 
explained in the cost of roasting : — 

Dollars. 

Labour for charging and discharging I'OO 

Two leachers at 1-00 doUar 2*00 

One man preparing calcium sulphide 0*75 

Sulphur, 594 lbs. at 6 cents ^'^'^ 

Lime, 180 lbs. at 0-6 cent 0*90 

One man roasting precipitate at $1*00 (one-half) O'oO 

Wood for roasting precipitate 0-50 

Management, office, mechanics, assay office l'7S 

Oil, light, filter cloth, shovels 1*50 

Steam for pump, and sulphide solution were charged to roasting — 

Total cost 12-50 

or cost of leaching per ton of ore, 1*47 dollars, Mexican currency.* 

Total cost of reduction, not including stamping : — 

DoiUm. 
Roasting in the reverberatory furnace ... 3*67 
Liziviation 1*47 

Mexican dollars 5*14 per ton of ore. 

Mr. Hof mann noticed that heavy brown fumes were emitted from the 
ore in roasting it in the muffle furnace under certain conditions, and was 
led to suspect the presence of cadmium in the del Oro ore in considerable 
quantities. Further investigations proved this to be the case. The cad- 
mium leaches out along with the zinc, and as long as there is zinc in the 
solution, cadmium will be found. The fact that the cadmium is brought 
into solution by the regular operation of the process for extracting the 
silver, permits of its extraction (as a bye-product) at very small cost. 

The analysis showed that the base-metal solution of the del Oro ore 
is remarkably free from metals which are precipitable by zinc ; if, therefore, 
the more concentrated part of the base-solution be conveyed into tanks 
(like those devised and recommended by Mr. Stetefeldt), for precipitating 
the copper and silver of the base-metal water with scrap-iron, and metallic 
zinc is introduced, it will precipitate the cadmium, copper, and silver. The 
base-metal solution is acid enough, but the addition of some sulphuric 
acid hastens the process. 

It is more profitable to manufacture cadmium sulphide than to produce 
the metal. The metallic precipitate, after being washed, is boiled with 
dilute sulphuric acid. Cadmium dissolves, while the copper will remain 

* The Mexican dollar was at the time in question, the writer belieTes, worth, 3s.; 
at present it is worth 28. 9d. 



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PROCBSSBS OF OHB TBEATMBNT. 827 

as a sediment ; and so will lead if it be present. The solution is decanted, 
filtered, and the cadmium precipitates as cadmium sulphide by sul- 
phuretted hydrogen. Cadmium sulphide is a brilliant and valuable paint. 
Experiments on a large scale showed that from 2 to 3 lbs. of cadmium 
sulphide could be precipitated from the base-metal solution derived from a 
ton of ore. 

The best orange-yellow of cadmium is obtained by precipitating with 
sodium sulphide, but the solution must first be made alkaline with caustic 
soda. 

Mr. P. M. Watson in a letter to The Engineeriug and Mining 
Journal, New York, of April 8th, 1893,* speaking of the Kussel process 
at Sombrerete, Zacatecas, says : — The ore runs roughly 10 per cent, of 
blende, 10 per cent, of galena, 80 per cent, of iron pyrites, and the rest 
mostly quartz containing on an average about 20 per cent, of sulphur. 
The old reverberatory furnaces used for roasting (taking six months* 
average) showed a roasting chlorination of 88*5 per cent., but the loss from 
volatilization was very heavy (the last six months' average being 16*6 
per cent., and before it had risen to as high as 24 per cent). By consider- 
ing the two lospes Mr. Watson therefore places their efficiency at 78*8 per 
cent. The extraction of sulphides during this period was about 73 per cent., 
and the total cost, including grinding, was about 8 dollars^ Mexican 
currency, per ton, crushing with rolls. He advocates using stamps in 
place of them. The ordinary Stetefeldt furnace also does not appear to 
have been more successful in this case than with the San Francisco del 
Oro ore, but Mr. Watson considers that it might be modified to give good 
results, and he considers that with a remodelled mill 85 per cent of the 
raw ore value could be extracted at a cost of not more than 6 dollars, 
Mexican currency, per ton. 

Trough-lixiviation. 

This system is a continuous one — a modification of tank-lixiviation — 
the chemical reactions are the same, but the time of leaching is enormously 
shortened, and the manipulations are simpler and more labour-saving. It 
is particularly adapted for large works, and for ore which on account of 
lead requires a long leaching time. 

While the silver from all the other silver-bearing minerals can be easily 
and quickly extracted as chloride, that portion contained in the galena 
dissolves very slowly. The larger portion of the silver may be in fact 
extracted in a few hours, while the remainder will take days. The 

• Page 316. 



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828 PROCESSES OF OBE TREATHENT. 

roasted del Ore ore, for example, filters quickly, but if the ore contain 10 
to 11 per cent, of lead, the silver-leaching time is 4 days, and if it contain 
15 to 17 per cent, of lead the time is increased to 5 or 6 days. 

A description of trough-lixiviation is given by Mr. Hofmann in The 
Engineering and Mining Journaly New York, of September 10th, 1887, 
November 26th, 1887, and March 16th, 1 889,* from which these particulars 
are taken. Silver chloride contained in roasted ore almost instantly 
dissolves if rapidly brought in contact with a proper volume of moving 
sodium hyposulphite solution. No more than | to 1^ minutes are required, 
and it is rather the quantity or volume than the concentrated state of the 
liquid solvent, that produces this effect ; it is in foot the principle upon 
which the process depends. 

In the tanks the amount of solution which comes in contact with 
the ore is regulated by the latter's filtering capacity. The operator can 
slightly increase the speed of filtering and so increase the quantity of solu- 
tion used, by producing a vacuum under the filter bottom, but he cannot 
produce and maintain at will a certain favourable proportion of ore and 
solvent, which is of such importance for a quick and thorough extraction. 
If, however, the ore be introduced into a running stream of the solvent, 
the operator has it in his power to produce and maintain any desired 
proportion. 

Instead of charging the ore in tanks, and permitting the solvent to 
filter through, it is dissolved outside the tanks in troughs, while the ore 
is moving in and with the stream of solvent, and the tanks are only used 
for the separation of the solid from the liquid. The ore from the furnaces 
is dumped into bins, from which it is mechanically and evenly charged 
into a perpendicular square tube 12 by 12 and about 2 feet in height, 
which is crossed by several sprays or sheets of water, closing it near the 
top and bottom. The dust caused by the contact of hot ore and water 
is absorbed by the top and bottom sheet of water, and cannot escape, while 
the steam generated is condensed. 

The pulp, when leaving the perpendicular tube, enters a grinding 
machine of similar construction to the German kegelmtihle, an arrange- 
ment which answers better than an agitator, which was first proposed for 
the purpose of mixing the ore with water (to prevent it being carried 
down the trough in bulk), and to mash and grind up any lumps it con- 
tains. The mill discharges the pulp into the base-metal leaching-trough 
of triangular section, which leads to the settling-tanks. 

•Pages 185, 393, and 255 respectively. 



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PBOGBSSES OF ORE TBBATMENT. 829 

By this system, the whole cooling-floor manipulations are avoided, 
likewise the filling of cars on the cooling-floor and the transportation of 
the moistened ore to the tanks, also the shovelling out of the tailings from 
the tanks, which is a great saving of manual labour, without involving 
much extra machinery. It requires two men per shift to bring the ore 
from the furnaces to the bins, one man in the base-metal department, and 
one man and a helper in the silver-leaching department. The stirring of 
the silver solution in precipitating is done by mechanical stirrers, which 
do excellent work. 

The rapidity of the extraction requires quicker circulation of the solu- 
tion entailing the use of a larger pump ; but Mr. Hofmann considers the 
extra expense of this a very small drawback. The hot ore warms the 
water for base-metal leaching, without incurring extra expense or labour. 

The proportion of water depends on the amount of base-metal chloridei« 
contained in the ore, and has to be so regulated that the resulting base- 
metal solution is too dilute to dissolve silver chloride. This is easily 
arranged, by gradually increasing the stream of water while maintaining 
the same supply of ore, and testing the resulting solution for silver. 

The length of the trough depends on the character of the ore, but 
150 feet from the mill to the first tank will, in most cases, be sufficient. 
The inclination should not be less than f inch to the foot. The trough can 
be arranged in zigzag, but has to lead over all the tanks. 

In the line of the trough above each tank there is a square box, 14 by 
14 by 10 inches, the bottom of which is provided with a plug-hole in 
order to permit of any desired tank being charged. 

The tanks have in the centre of the bottom a sluice-hole 6 inches in 
diameter, to which is attached to the outside by means of a flange a short 
piece of cast-iron pipe of about the same diameter. This pipe is like a 
gas-pipe elbow, and can be tightly closed by pressing a rubber gasket 
against the outside flange. This valve is worked from a platform along- 
side the tanks. This pipe must be well coated with asphaltum varnish. 
Around the sluice or discharge-hole the filter is arranged in funnel-shape, 
having an inclination of | inch to the foot. The filter-cloth must be 
well fastened round the outer and inner circle. The central position of 
the discharge-opening and funnel-shape of the filter-bottom permit of 
quick and perfect sluicing. A tank with a level filter-bottom, if large, 
can be sluiced clean through a side gate. The space below the filter 
is provided with the usual outlet-pipe. Close under the filter is inserted 
from outside a | inch pipe which, connected with 1 inch hose, reaches 
the rim of the tank for the escape of the air. Before the tank is 



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830 PROCESSES OF ORE TREATMENT. 

used for operation, a wiied rnbber-hose is connected with both the water 
and the solution-pipes, and so placed irom above that the lower or outlet 
end enters the discharge-pipe through the central hole in the bottom. 
The object of this hose is to inject a stream of solution at the bottom of 
the ore (in the outlet-pipe), when the tank is to be sluiced out for silver 
leaching. 

The stream undermines the tightly-packed ore which gradually caves 
in, until a funnel-shaped opening is made through its depths. Then one 
or more streams are allowed to play on top of the ore until it is all sluiced 
out. The hose in the discharge-pipe — ^which must be stiff in order not to 
be flattened — is allowed to remain, in order to prevent the discharge-hole 
from being clogged by a too sudden rush of ore. Before starting the 
operation the discharge-pipe is filled with water through the central hose, 
the lower end being covered, in order to keep it filled with water to pre- 
vent obstruction from the ore. 

The tanks are placed on the same level in two rows close together, and 
are connected by pipes in such a way as to permit of any desired tank 
being disconnected without disturbing the communications of the others. 
The connecting-pipes are also on a level, placed a few inches below the 
rim of the tanks, and well coated with asphaltum varnish. Their diameter 
depends on the capacity of the works. Each tank is provided with an 
outlet (on the level of the connecting-pipes), which discharges below the 
bottom into the base-metal trough, the latter being connected with the 
outlet-hose from under the filter-bottom. The connecting-pipes and 
upper outlets can be closed with wooden plugs from the inside of the 
tanks. 

Base-metal Leaching. — At starting, the stream of roasted ore and water, 
after having passed through the whole length of the base-metal leach 
trough, is allowed to enter the tank by opening the hole in the bottom 
of the small square box which intersects the trough above the tank. 
The ore will gradually fill the first tank, while the base-metal solution 
after reaching the level of the connecting-pipe will flow into the 
next tank, and when this is filled, into the next tank, and so on through 
all the tanks until it finds the outlet of the last tank, through which 
it will discharge into the base-metal trough. The motion of the 
solution in each tank is so slow that, by the time it reaches the last 
outlet, it is clear. A board, placed edgeways a few inches below the 
surface and across the tank, will prevent the formation of a diametrical 
stream from one pipe to another, and greatly assist in clearing the solution. 
If the proper proportions of water and ore have been used, the base-metal 



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PROCESSES OF ORE TREATMENT. 831 

solufcion will not contain any silver, and can be allowed to ran to waste. 
When the first tank is filled with ore, the connecting-pipe is closed, and 
stream of pulp transferred into the second tank, all other connexions 
remaining unchanged. The outlet-hose below the filter-bottom of the 
first tank is now opened, and the solution still contained in it is allowed 
to drain off. As soon as it disappears below the surface of the ore some 
clear water is added to force out the remainder of the base-metal solution. 
The first tank is now ready for silver leaching. 

Silver Leachmg. — In their passage through the trough from the mill to 
the tanks, all the soluble base-metal chlorides have dissolved, and the 
charge of the first tank having been treated, as above described, is now 
ready for silver leaching. The rabber gasket of the dischaige-pipe is 
pulled back, and sodium-hyposulphite solution is turned on through the 
central hole, and the whole chaise sluiced out. Ore and hyposulphite 
solution discharge into a trough under the first and last tanks, which are 
connected with the silver-leach trough. At first, before other streams 
of hyposulphite solution can be played on the surface of the ore, the 
pulp is diluted by an extra stream in the silver-leach trough. Ore and 
solution now pass through a trough, not less than 150 feet long, to a 
similarly arranged set of tanks. 

When the pulp reaches the first tank, the solution has dissolved all 
the silver chloride, and the sand drops as tailings into the tank. The silver 
solution has also to pass through all the tanks and leaves the last one 
clear. It is conveyed to the precipitation-tanks. When one tank is filled 
with tailings, it is disconnected from the others, and the pulp allowed to 
fiow into the next one. The outlet-pipe under the filter-bottom is opened, 
the remaining silver solution allowed to drain off, and the part retained by 
absorption displaced by water. Where water is scarce, the base-metal 
solution can be accumulated in the outside storage-tank and used for 
sluicing the tailings. The proportion of solution and ore to be used 
depends on the nature of the ore, and has to be ascertained for each kind. 
Ore containing lead requires most solution. It is best to determine 
the proportion in weights, as it makes it easy to calculate the required 
capacity of the different tanks, pipes, and pumps, for a given capacity 
of milL 

Mr. Hofmann's tests, he states, show that the minimum quantity of 
solution required is 3 to 5 times the weight of the ore, and the maximum 
18 to 20 times. The weight of the solution is, for convenience, taken as 
equal to water, 1 cubic foot = 62*5 lbs. In most cases 10 parts of 
solution to 1 of ore will be sufficient. Assuming this proportion, and 



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882 PROCESSES OF ORE TREATMENT. 

taking 1 cubic foot solution as 7*5 gallons, and 1 gallon as 8*88 lbs., 
we find that in order to lixiviate 40 tons per day, it will require 8,200 
cubic feet or 24,000 gallons of solution to be daily pumped to the upper 
reservoir and circulated. This, theoretically, would require a pumping 
capacity of 16*66 gallons per minute, and precipitating facilities for 1,000 
gallons per hour. By erecting a temporary trough of not less than 150 
feet in length, and a mixing-box at the upper end, the required propor- 
tions of solution and ore can readily be determined by a series of 
experiments. The samples have to be taken at the lowest end of the 
trough, while the pulp is dropping into the receiving-tank. The vessel 
with which the sample is caught mast be large enough to receive the 
whole stream during the time the sample is caught. Sufficient time must 
be allowed for the ore to settle. The clear solution is carefully decanted, 
and the sediment placed on a filter, washed well with water, dried, and 
assayed. Before subjecting it to the solution-test, the ore has, as a matter 
of course, to be treated with water to remove the base-metal chlorides. 

Mr. Hof mann states the advantages of trough-lixiviation as follows : — 

At first sight it would appear that very dilute silver solutions are 
obtained, and have to 'be treated in the precipitation-tanks. This^ 
however, is not the case. The resulting silver solution maintains a uniform 
strength in silver and other soluble metal salts, and is of about the same 
strength as the whole filtrate of one charge in tank-leaching would be, if 
accumulated in one precipitation-tank. In tank-lixiviation very strong 
solutions are formed at the beginning, and very dilute ones towards the 
end, and as it frequently happens that a tank-full of such very dilute 
solutions has to be precipitated by itself; a uniform strength is in fact 
by fiir preferable. 

This method of lixiviation allows the operator to bring the ore 
in sudden contact with any desired quantity of the solvent, and offers 
the means in this way, of overcoming some very annoying chemical and 
mechanical difficulties encountered in other lixiviation processes. Lead 
sulphate reduces the dissolving energy of sodium hyposulphite for silver, 
and this is why the lixiviation of lead-bearing ores is so exceedingly slow 
and requires such an extensive plant. 

In the ordinary lixiviation, the solution becomes more saturated with 
lead sulphate as it descends through the ore and loses proportionately its 
dissolving energy. As the solubility of the lead sulphate increases with 
the concentration of the solution, a stronger solution does not hasten the 
process ; but if the ore be brought rapidly into contact with a large 
volume of hyposulphite solution, the latter retains enough of its dissolving 



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PB0CE8SES OF OBE TREATMElSrT. 883 

energy to produce a quick extraction. The presence of lead sulphate 
therefore does not retard trough-lixiviation, it merely entails the use of 
larger quantities of solvent. The rapidity with which the silver dissolves, 
also materially lessens the unfavourable influence of caustic lime. The 
possibility of bringing the ore into contact with any desired quantity of the 
solvent has the further advantage of preventing the base-metal solution 
from dissolving silver. The resulting solution need only be sufficiently 
dilute. It does not take much more water than in the ordinary leaching, 
when the bulk of the silver is dissolved by the base-metal chlorides, while 
the solution is very concentrated. Shortly after the beginning, no more 
sQver is dissolved; if, therefore, the charge of ore could have been 
brought at once into contact with the whole quantity of water used in 
washing, Mr. Hofmann thinks much less silver would go into solution. 
Olayey ores and flue-dust may be successfully treated by trough-lixiviation 
regardless of their filtering property. 

In ordinary leaching, each tank-charge is in a different stage of the 
process, and this necessitates great care and attention and keeping a 
separate record of each tank. In trough-lixiviation, the operation being 
continuous, attention need only be concentrated on one tank in each 
department to prevent it from being overcharged. Although the process 
is divided into two departments (the base-metal and silver leaching) the 
manipalation is materially simplified, the tanks being charged automatically 
by the stream of the respective solutions, and the costly handling in cars 
is obviated. Leaching works built on this plan will require more grade, 
and it will be preferable to have the roasting and base-metal leaching 
done in the main building ; and the silver settling and precipitation- 
tanks, with all the other apparatus required for the final treatment of the 
precipitate, in a separate department lower down; the two being con- 
nected by the silver-leach trough. 

The principle of this method can be tested in the laboratory by intro- 
ducing 20 grammes of roasted ore, which has previously been washed into 
a graduated cylinder of 1,000 cubic centimetres, in which is contained 
200 cubic centimetres of sodium hyposulphite solution. The top of the 
cylinder has to be tightly closed with the palm of the hand, and the 
glass brought into a horizontal position and oscillated, in order to make 
the ore and solution pass quickly from one end to the other to imitate 
the current in a trough. After the oscillating motion has been continued 
for about 2 minutes the contents of the cylinder are emptied into a filter, 
and washed with water to displace the silver solution from the sand and 
filter-paper. 



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834 



PROCESSES OF OBE TBEATUENT. 



It will be found that all the extractable silver has been dissolved, and 
the residues will correspond with those obtained in the regular chlorina- 
tion assay. If the result of a iirst trial be not satisfactory, it is due to 
a fault in the quantity of solution, more of which must be used in the 
next test, and so on, till the results are accurate and the required propor- 
tions of solution and ore are ascertained. 

Trough-lixiviation was first used in the mill of the North Mexican 
Mining Co., Cusihuriachic, Chihuahua, Mexico. This mill was originally 
arranged for tank-lixiviation, but the ore hardened like cement, and 
did not permit any solution to pass through. Trough-lixiviation, how- 
ever, enabled the ore to be worked rapidly, and the resulting tailings 
agreed with the chlorination test. 

Mr. Hofmann gives a number of experiments and details with regard 
to trough-lixiviation in The Engineering and Mining Journal^ New York, 
of March 16th, 1889,* and in the Transactions of the Americnn InsHtu- 
Hon of Mining Engineers^ February, 1888.t These cannot, however, be 
reproduced here in detail. As the saving in time is, however, one of the 
chief claims of the process, the writer may instance some comparative 
figures Mr. Hofmann gives, comparing it with tank-lixiviation treating 
del Oro ore : — 

Time taken in tank-lixiviation : — 

Charging 

Base-metal leaching 

Expelling the water by solution 

Silver leaching 

Expelling the solution by water 

Total 

Time taken in trough-lixiviation : — 

Base-metal leaching and iilling the tank ... 
To drain the wash-water from the top of ore 
To expel the base-metal solution by water 
To expel the water by hyposulphite solution 
Silver leaching (sluicing with solution) ... 

Draining solution from top of ore 

Expelling the solution by water 

Total 16 5 

Treating the del Oro ore by trough-lixiviation, Mr. Hofmann found 
in silver leaching that, using a solution with a strength of 0*50 ounce per 
ton, the best results were obtained with the proportion of 1 of ore to 8*4 
of solution or 108*8 cubic feet or 816 gallons of solution in circulation 



Honra. 




3 




8 




1 




96 




1* 


... 1091 


Hn. Mln. 


3 


6 


. 


34 


S 


25 


1 


20 


3 


36 





34 


2 


30 



Page 255. 



t Page 662. 



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PB00AS8BS OF OBB TBBATMENT. 835 

per ton of ore treated. Bat in trongh-lixiviation, 658 cubic feet, or 4,985 
gallons of solution were required per ton. The proportion of 1 to 3'4 
gave tailings carrying only 8*59 ounces per ton. In evidence of the 
statement that by producing a sufficiently dilute base-metal solution it 
will not contain any silver and may be allowed to run to waste, 
Mr. Hofmann cites the following test : — One litre of the 702 gallons of 
base-metal solution was precipitated with calcium sulphide. The precipi- 
tate, after fluxing and treating like an ordinary ore assay, returned no 
more than 0*0002 gramme of fine silver, 702 grammes will therefore 
contain 0*582 gramme, which represented the total amount of silver 
dissolved from 8*89 tons of ore, or 0*06 gramme or 0*002 ounce of silver 
per ton,' which is practically nothing. 

Other points mentioned are, while in tank-Uxiviation the rate of filtra- 
tion was 8^ inches per hour, in trough-lixiviation it was 12 inches per hour. 
The number of tanks required in trough-lixiviation is much less than in 
tank-lixiviation, and while the roasted sulphides obtained from the trough- 
process contained 20*9 per cent, of fine silver, those obtained from the 
tank-process during the same week and from the same lot of ore only 
contained 17 per cent, fine silver. 

Some of the most interesting figures may be summed up as follows : — 

In Tank- In Trough- 

UxlTiation. UziTiatlon. 

Quantity of water required for baae-metal leaching, 

including sluicing, per ton 943 gals. 1,129 gals. 

Quantity of hyposulphite solution which has to 

circulate for each ton of ore 4,935 „ 816 „ 

Time required to treat one tank-charge of ore ... 109 h. 30 m. 15 h. 5 m. 

Total quantity of water required for 100 tons of ore 

per day 94,300 gals. 112,900 gals. 

Total quantity of hyposulphite solution per day to 

work 100 tons 493,500 „ 81,600 „ 

Loss of silver in base-metal leaching per ton of ore... 0*26 oz. trace. 

Extraction of silver in both methods the same. 

In connexion with the Hofmann gold-and-silver chlorination process, 
which has been mentioned in the earlier part of this paper, it is to be 
noted that after the silver has been extracted, the solution of hyposulphite 
used for leaching is allowed to run out till it disappears under the surface 
of the ore, when clear water is introduced, in order to displace the solution. 
The desilverized ore must then be removed from the tank to a diy-kiln, 
where it is left till the surplus water has evaporated. After this it is 
charged back into the tank still moist. 

This second handling and drying cannot be dispensed with, as the ore 
after leaching is too wet to permit of the free passage of chlorine. If the 



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836 PROCESSES OF ORE TREATME19T. 

ore be cupriferous, much copper will be carried out with the gold solution 
(after it has been chlorinated), colouring it green. 

An application of the leaching process to the pan-amalgamation of 
very base ores, which has been invented by Mr. Kustel, deserves notice. 
He states that it is applicable to silver ores, like those of Flint, Idaho, 
containing base-metals, and also to auriferoas copper ores, which by 
their nature require roasting, as the amalgamation of gold is very much 
obstructed by the presence of copper salts. If there be soluble chloride of 
silver in the roasted ore, and besides this, soluble chlorides of copper, lead, 
antimony, and zinc, they will all, as a matter of course, be decomposed 
and amalgamated. 

All take part in consuming and flouring the quicksilver and in destroy- 
ing the pan, such a combination as the above hindering the amalgamation 
of the silver and gold. The base-metal chlorides being soluble in water, 
while the chloride of silver is not, it is a simple expedient to dissolve out 
these salts by leaching with hot water, and thus remove them from the 
ore, prior to amalgamation. The ore being thus divested of its rebellious 
features, gives excellent results in the pans. 

LixrviATiON verstis Amalgamation. 

In comparing the Kussel process with amalgamation, Mr. Stetefeldt* 
enumerates the principal points in favour of lixiviation as follows : — 

1. In amalgamation, the coarseness of crushing, without considering 

the question of roasting, is limited by the capacity of the 
settler to work off coarse sands without loss of quicksilver. 
In lixiviation pulverizing as coarse as possible is desirable. 

The limit of coarseness depends on the character of the 
ore, and principally upon the manner in which the silver- 
bearing minerals are distributed in the gangue. 

2. The original cost of the lixiviation-plant is much lower than 

that of pans and settlers, and a further saving is effected by 
a reduction in the size of engines and boilers. 

8. In amalgamation the pans and settlers consume not less than 
1^ horse-power per ton of ore. The power for pumping 
solutions, etc., in the lixiviation process, is merely nominal. 

4. In large mills the quantity of quicksDver in solution repre- 
sents a capital of 80,000 to 40,000 dollars (£6,250 to 
£8,388 6s. 8d.), while the stock of chemicals required for 
lixiviation costs less than one-tenth of this amount. 

♦ 27ie Liaivwtion of Silver Ores^ page 4. 



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PB0CRS8E8 OF ORE TREATMENT. 387 

5. With the finaael improvements the percentage of silver 

extracted by Ikiviation is in most cases higher than by 
amalgamation. 

6. Lixiviation by the Rossel process requires a less careful chlor- 

idizing-roasting, and in consequence a lower percentage of 
salt may be used in roasting. 

7. Ores that can be successfully treated by raw amalgamation give 

often better results by lixiviation with extra solution. 

8. The value of the quicksilver lost, and cost in wear and tear of 

the pans and settlers amounts to more than that of the 
chemicals consumed in the lixiviation process. 

9. The lixiviation process permits of the extraction of copper and 

lead as valuable bye-products. 

10. Amalgamation is invariably injurious to the labourers' health. 

11. Where gold-bearing silver-ores have been roasted with salt, 

lixiviation extracts in many cases more gold than amalga- 
mation. 
The disadvantages of lixiviation as compared with amalgamation 
are: — 

1. Lixiviation requires more chemical knowledge and a more 

careful supervision of the operations. 

2. The handling of large volumes of solutions is a disadvantage 

common to all humid processes. 

3. There is more danger of losing silver by careless manipulation, 

and by leakage of badly constructed plant. 

4. In the lixiviation process the precious metals are obtained in the 

form of sulphides. The conversion of the latter into bullion, 

requires more skill and is more expensive than the handling 

of amalgam. 

The chemistry of the process has been most ably discussed and dealt 

with by Mr. Stetefeldt and Mr. Ellsworth Daggett,* and treated of in the 

Report of the Galifomian State Mineralogist^ 1888, which contains an 

independent article upon the hydro-metallurgy of silver, as well as a 

critical review of the Russel process by Mr. C. H. Aaron.f 

The writer gathers from these various sources that it is with roasted 
ores which have an alkaline reaction caused by the presence of caustic 
lime (as, for example, the alkaline arsenical ores of Las Yedras, Sinaloa, 
Mexico,) that the Russel process, as compared with the ordinary Yan 
Patera process (leaving the Eiss process out of the question), has 
* Trans, Am. InH. Min. Eng,y toI. xtI., page 362. t P<^ S^^* 

VOL, T^WBa^. 22 



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838 PBOGESSES OF ORE TREATMENT. 

acliieyed its greatest sacoess, bat it is possible that it may meet with 
a fonnidable rival in this provinoe in the new departure of pyritic 
smelting.* 

Looking at a number of examples that are given it would appear that 
the extraction in the mill by the Patera process shows a difference in 
certain instances, in favour of the Bussel process, of 22 to 30 per cent, of 
the silver extracted. 

A table given by Mr. C. H. Aaron also shows the resulls of a series of 
competitive mill-runs, extending over eight months at the Ontario Mill 
(on Ontario ore), in which the percentage extracted by the Russel process 
varied from 84-7 to 93*9 per cent, (or on the average about 91'17 per 
cent.) as against 65'3 to 84*9 per cent, (or on the average 77"4 per cent.) 
extracted by amalgamation, treating ore which ran about 47 ozs. per ton 
roasted. The tailings from the amalgamation still carried 10*76 ozs. per 
ton on the average, whilst the lixiviation-taUings only ran 4*3 ozs. 

Experiments at the same works from November, 1887, to January, 
1888, on an ore which ran 43*76 ozs. in silver, showed that 82*1 per cent, 
was extracted by amalgamation, as against 91*5 per cent, by the Bussel 
process. 

On the whole, however, taking the results of five different mills it 
would seem that whilst amalgamation gave an average of 80*7 per cent., 
the fiussel process averaged 89*4 per cent., or 8*7 per cent, above the 
results of amalgamation, and 4*8 per cent, better than could be extracted 
with ordinary solution making the latter tests in the laboratory. 

It is therefore to be inferred that, in the case of certain ores which 
have been specified, the Russel process extracts more silver than amalga- 
mation, but it is to be also noted that in the case of four of the mills 
taken as examples, the percentage extracted by amalgamation is certainly 
10 per cent, less than in many mills where roasting-milling is practised, 
and therefore cannot be altogether regarded as typical of the capabilities 
of the latter process in certain cases. 

The ore, for example, of the Ontario mine is very base, containing, 
as before pointed out, zinc, lead, and silver sulphides, as well as chlorides, 
in a quartz gangue, and therefore the comparative success of the process 
in this instance, even from a purely chemical standpoint, scarcely fore- 
shadows it as a universal fact. 

Next, as regards capital outlay, Mr. Stetefeldt gives the cost of a plant 
for dry-crushing and roasting 80 tons a day as follows : — 

• It is to be regretted that more details of the cost and working of this prooess 
are not at present available. 



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PROCESSES OF OBE TREATMENT. 



839 



Buck-eye engine, 72 to 121 'horse-power 

Knowles, feed-pump. No. S 

Heater ( 

Air-pump and condenser ) 

Two Krom rock-breakers 

Three double-shelf dry kilns 

Two sets Krom 26 inches rolls 

Two Krom screens 

Stetefeldt furnace 

Hoist, with cage and safety-catches ... 
Shaftings, bearings, pulleys, wire-rope 

transmission 

Electric light plant, with separate 

engine for dynamos 

Belting 

Elevators, conveyors, feeders, hoppers, 

cone-puUey 



JchkinLbf 


DoUan. 


15,000 ... 


1,776-00 


640 ... 


275-00 


2,000 ... 


( 175-00 
45000 


12,000 ... 


1,500-00 


70,000 ... 


2,700-00 


29,000 ... 


4,500-00 


1,200 ... 


800-00 


49,000 ... 


8,000-00 


2,000 ... 


600-00 


18,000 ... 


1,300-00 





1,700-00 





1,000-00 





1,000-00 



s. d. 



20,776-00 - 4,828 2 6 



6,772-70 ... 1.310 .19 7 



Add the cost of four 40 horse-power high- 
pressure boilers 

Add the cost of the lixiviation-plant 
proper,* with a capacity of 80 to 170 
tons of roasted and raw ore, if the 
tailings are removed by sluicing ; 70 
to 140 tons, if the tails are to be 
shovelled 

Add the cost of painting vats and tanks 
with three coats of white paint, say, 
746 lbs. of white lead and 41-7 gals, 
oil, occupying one man 34 days to 
lay on 

Add the cost of plant for refining sul- 
phides by the humid process esti- 
mated (erected) at 

Add the cost of grading and founda- 
tion to the mill structure and plant 
it contains (which it is only pos- 
sible to figure in accurately by 
knowing the exact quantities of 
material and the time of skilled and 
ordinary workmen employed on the 
job) 

• This includes finished lumber and hoops for 6 lixiviation-tanks, 3 storage- 
tanks, and 6 precipitating-tanks, 1 sulphide storage-tank, 2 solution-sumps, cast and 
wrought-iron fixtures for vats and tanks, pipes, valves, steam-hose, 1 sodium 
sulphide mixing and 2 storage-tanks, 8 Korting ejectors. No. 4 Knowles fire-pump, 
(siBe A), for sluicing tails; Knowle plunger-pump for pumping solutions, 1 John- 
son 18 inches filter-press, 1 Johnson pressure- tank, and a Knowles feed-pump, 
No. 2, for boiler. 



5,000-00 ... 1,041 13 4 



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340 



PBOOESSES OF ORE TREATMENT. 



Add finally freight and transport 
charges^ depending on the locality, 
and it will be foand that the total 
cost is not so far short of a pan- 
amalgamation plant of the same 
capacity as might be supposed ... ... „, 

Now, let UB glance at the working expenses of running a lixiviation- 
plant which are given by Mr. Stetefeldt for a mill of 80 tons capacity 
per day : — 

Fuel, engine and boilers* 

Boiler lixiviating-building 

Dry kiln ore and salt 

Stetefeldt farnace, depending on quality 

of wood and character of ore 

Sulphide refinery for roasting, refining, and 
melting bars in a reverberatory furnace 

Total ... 



Oorda of Wood. 


TonaofOoaL 


6 to 6 


2ito3 


3 


n 


H 


If 



6} to 8} 



19 to 22 



The cost of labour per day would be as follows : 

Ko. of Workmen. 



Engine and boilers . 



Ore-house 



Hoan of Work. 
... 12 



Dry kilns 



Rolls 

Stetefeldt furnace 
Cooling-floor... 
Lixiviations ... 



2 engineers 

2 firemen 12 

2 rock-breakers 10 

2 wheeling ore 10 

4 bringing ore from ore-hoQgc and charging kilns 12 

2 discharging kilns 12 

2 firemen also attending salt-kilns and assisting 

rolls 12 

2 machinists 12 

3 firemen 8 

12 discharging, cooling, and charging vats ... 8 

2 lixiviators 12 

3 helpers 12 

2 precipitators 12 

2 firemen on boilers, pumps, and pipes 12 

2 handling sulphides 12 

roasters and refiners 10 

night foreman 12 

machinist 10 

carpenter 10 

blacksmith 10 

general helps 12 

assayers' help 12 

„ 1 blacksmith's Help 10 

„ 1 electrician — 

„ 1 bookkeeper — 

„ 1 assayer — 

„ 1 chief metallurgist — 

„ i chief mining engineer — 

„ 2 men and team hauling wood — 

Total ..."62J 

^ It is assumed that 1 cord of wood is equal in effect to 1,000 lbs. of coal. 



Refinery 


... 2 


MiU 




„ 




1, 




»» 




„ ... ... 




„ 





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PROCESSES OF ORE TREATMENT. 341 



The daily consamption of chemicalB is as follows : — 



Copper stilphate 
iSodium hyposulphite 
Caustic soda ... 

Sulphur 

Sulphuric acid ... 



Per Ton of Ore. 
Lbe. 

, 1-8 to 9-6 

. 1-5 to 7 

. 1-4 to 7-76 

0-9 to 5 

0-25 to 1-80 



The water required is fix)m 9 to 55 cubic feet per ton of ore, exclusive 
of that used for sluicing tailings. 

The cost of wear and tear to cover all ordinary breakages, and wear 
and tear of machinery, boilers, screens, dry kilns, furnaces, lixiviation- 
plant, and refinery, including lubricants, electric light, and sundries, is 
about £7 58. lOd. per day. For plants of small capacity the expenses 
per ton of ore, for labour, are, of course, materially increased. To the 
above must be added insurance, taxes, interest, legal expenses, etc., and 
amortization on the capital invested in the mill. 

The total expenses at Cusi, Mexico, including refining, are said to 
have been £2 lOs. 4d. i)er ton, using the Russel process. 

For roasted ore at the Sierra Grande mill. Lake Valley, the total mill 
expenses for 60 tons per day were estimated by the general manager, 
Mr. Hadley, at 19s. 4d. per ton. 

At Parral, Mexico, the total expenses for the treatment of tailings 
(from ore which had originally been rojisted and lixiviated by the ordinary 
process) were 8s. 9d. per ton for 40 tons per day. Treating roasted ores 
at the rate of 10 tons per day the total expenses were £1 18s. l^d. per ton. 
The cost of raw-leaching tailings at Silver Reef, Utah, treating 25 
tons per day (the tailings assaying 6^ to 9 J ozs. of silver but no gold), is 
given by Mr. Egleston* as 6s. lOj^d. j^er ton, the percentage extracted 
averaging 55 to 60 per cent. The presence of copper carbonate in these 
ores caused the sulphides to have a low percentage of silver (3,560 ozs. 
per ton) and a high tenour of copper. 

Treating tailings from amalgamation-works at Silver City, concen- 
trated up to 80 ozs. per ton silver, it is asserted that the Van Patera 
process only extracted 38 per cent, against 72*4 obtained by the Russel 
process. 

Mr. Stetefeldt states that in a well-constructed lixiviation-mill the 
total expenses for treating 75 tons of raw ore per day should not exceed 
128. 6d. per ton, and under favourable circumstances should fell as low 
as 10s. 5d. per ton, particularly if the crushing were done by rolls instead 
of stamps. 

* Metallurgy of Silver, page 632. 



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842 PBOGB88E8 OF ORE TREATMENT. 

The chemicals reqaired to be carried in stock for a lixiviation-plant 
of 80 tons daily capacity are estimated in an assnmed case as amounting 
to about £878 Os. 2d., to last for 60 days, including sodium hyposulphite 
in stock solution. 

Mr. Stetefeldt, page 213, says : " The Ontario mill expenses arc about 
£2 14s. 2d.* per ton, those for lixiviation would be about £1 Os. lOd. to 
£1 5s. less, or a difference in