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REPORT 
(2B oe 
f_ OF THE 

EIGHTH MEETING 


OF THE 


BRITISH ASSOCIATION 


FOR THE 


ADVANCEMENT OF SCIENCE; 


HELD AT NEWCASTLE IN AUGUST 1838. 


VOL. VII. 


LONDON: 


JOHN MURRAY, ALBEMARLE STREET. 
1839. 


1 as j py ‘ ; ey 
* PRINTED BY RICHARD AND JOHN E. TAYLOR, a 
ys ou JS Sa * 


RED LION COURT, FLEET STREET. 


CONTENTS. 


SE 
Tage 
Ossxcts and Rules of the Association .............. 0000 eee v 
Offerman, Couneil, VS389, ao) ejseeiays tm «leroy shite» odpertmers qeeacaen vili 
Table of Places of Meeting and Officers from commencement.... ix 
Table of Members of Council from commencement ...... se x 
Officers of Sectional Committees ..............02-. 000 eee ee xii 
Comm@spronideres INIETADERES 2 sei oe oo oieinye ds ee Moldyn = Couple ey aie xiii 
CMB AS TINERISO A CCOUMM nes WMA ans Voces puis c wlalsisus toss Ava hd ed eco’ a xi¥ 
Reports, Researches, Desiderata, &c.................... XV—XXVi 
Synopsis of Sums appropriated to Scientific Objects .......... xxvii 
Arrangements of the General Evening Meetings.......... eae 
Address by Mr. Murchison ......... 6. .000.eeece es ccenee ee XXKi 
pagers Pe OF RESEARCHES IN SCIENCE. 
Accitint of ¢ evel Line, measured from the Bristol Channel to 
the English hannel, during the Year 1837-8, by Mr. Bunt, 
under the Direction of a Committee of the British Association. 
Drawn up by the Rev. W. Waewext, F. R.S., one of the 
Committee ........ Be late athe dysyaye 3,0, \-6) 61m secteur dia 1 
‘Report on the Discussions of Tides prepared under the direction 
of the Rev. W. Wuewett, F.R.S., by means of the grant of 
money made for that purpose by the Association............ 19 
Account of the Progress and State of the Meteorological Obser- 
vations at Plymouth, made at the request of the British Asso- 
ciation, under the direction of Mr. W. Snow Harris, F.R.S. 
(Brawn up by Wir. Handi.) 26.00 98) sages ts Locke 24 


od a2 


iv CONTENTS. 


Page 
A Memoir on the Magnetic Isoclinal and Isodynamic Lines in the 
British Islands, from Observations by Professors Humphrey 
Lloyd and John Phillips, Robert Were Fox, Esq., Captain 
James Clark Ross, R.N., and Major Edward Sabine, R.A. By 
Major Epwarp Sasing, R.A., F.R.S. 0.0... eee eer ee eens 49 . 


First Report on the Determination of the Mean Numerical Values 
of Railway Constants. By Dionysius Larpner, LL.D.F.R.S.,&e. 197 


First Report upon Experiments, instituted at the request of the 
British Association, upon the Action of Sea and River Water, 
whether clear or foul, and at various temperatures, upon Cast 
and Wrought Iron. ByRosertMattert,M.R.LA. Ass.Ins.C.E. 253 


Notice of Experiments in Progress, at the desire of the British 
Association, on the Action of a Heat of 212° Fahr., when long 
continued, on Inorganic and Organic Substances. By Ropexrr 


MEAs rarer. VE BT Ar ree 0.95 x roo le erate tates line see eee Sle 
Provisional. Reports and Notices of Progress in Special Re- 

searches entrusted to Committees and Individuals .......... 315 
Report of the Committee for the Liverpool Observatory........ 316 


Notice of Apparatus for the Detection and Measurement of Gases 
present in minute quantity in Atmospheric Air. By Wu. West. 316 


Notices of Progress in Special Researches ..............+4-- 317 


Appendix to a Report on the Variations of the Magnetic Intensity 
(printed in Vol. VI.). By Major Epwarp Sasrnz, F.R.S., . 
Er eI OSETS oss OMe eee es Lite gens > 5. en 318 


For Contents of the Notices and Abstracts of Communications to the 
British Association for the Advancement of Science, at the New- 
castle Meeting, August, 1838, see pp. iii—viii. of the second portion 
of this Volume. 


Indices I. and II. ........ ch. tees eh PEEIROD S.A). POLS. 


For Catalogue of the Philosophical Instruments, Models of Inventions, 
Products of National Industry, &c., &c., contained in the First Ex- 
hibition of the British Association for the Advancement of Science, 
see the end of this volume. 


Plates IL.— XVII. 


OBJECTS AND RULES 


OF 


THE ASSOCIATION. 


OBJECTS. 


Tur Association contemplates no interference with the ground 
occupied by other Institutions. Its objects are,—To give a 
stronger impulse and a more systematic direction to scientific 
inquiry,—to promote the intercourse of those who cultivate Sci- 
ence in different parts of the British Empire, with one another, 
and with foreign philosophers,—to obtain a more general atten- 
tion to the objects of Science, and a removal of any disadvan- 
tages of a public kind which impede its progress. 


RULES. 
MEMBERS. 


All Persons who have attended the first Meeting shall be 
entitled-+o become Members of the Association, upon subscri- 
bing an obligation to conform to its Rules. 

The Fellows and Members of Chartered Literary and Philo- 
sophical Societies publishing Transactions, in the British Em- 
pire, shall be entitled, in like manner, to become Members of 
the Association. . 

The Officers and Members of the Councils, or Managing 
Committees, of Philosophical Institutions, shall be entitled, in 
like manner, to become Members of the Association. 

All Members of a Philosophical Institution recommended by 
its Council or Managing Committee, shall be entitled, in like 
manner, to become Members of the Association. 

Persons not belonging to such Institutions shall be elected by 
the General Committee or Council, to become Members of the 
Association, subject to the approval of a General Meeting. 


vi RULES OF THE ASSOCIATION. 


SUBSCRIPTIONS. . 


The amount of the Annual Subscription shall be One Pound, 
to be paid in advance upon admission ; and the amount of the 
composition in lieu thereof, Five Pounds. 

Subscriptions shall be received by the Treasurer or Secre- 
taries. 

If the annual subscription of any Member shall have been in — 
arrear for two years, and shall not be paid on proper notice, he 
shall cease to be a member. 


MEETINGS. 


The Association shall meet annually, for one week, or longer. 
The place of each Meeting shall be appointed by the General 
Committee at the previous Meeting; and the Arrangements 
for it shall be entrusted to the Officers of the Association. 


GENERAL COMMITTEE. 


The General Committee shall sit during the week of the 
Meeting, or longer, to transact the business of the Association. 
It shall consist of the following persons :— 

1. Presidents and Officers for the present and preceding years, 
with authors of Reports in the Transactions of the Association. 

2. Members who have communicated any Paper to a Philo- 
sophical Society, which has been printed in its Transacticns, 
and which relates to such subjects as are taken into considera- 
tion at the Sectional Meetings of the Association. 

3. Office-bearers for the time being, or Delegates, altogether 
not exceeding three in number, from any Philosophical Society 
publishing Transactions. 

4. Office-bedrers for the time being, or Delegates, not ex- 
ceeding three, from Philosophical Institutions established in 
the place of Meeting, or in any place where the Association 
has formerly met. 

5. Foreigners and other individuals whose assistance is de- 
sired, and who are specially nominated in writing for the meet- 
ing of the year by the President and General Secretaries. 

6. The Presidents, Vice-Presidents, and Secretaries of the 
Sections are ex officio members of the General Committee for 


the time being. 
SECTIONAL COMMITTEES. 


The General Committee shall appoint, at each Meeting, 
Committees, consisting severally of the Members most conver- 


RULES OF THE ASSOCIATION. Vil 


sant with the several branches of Science, to advise together for 
the advancement thereof. 

The Committees shall report what subjects of investigation 
they would particularly recommend to be prosecuted during the 
ensuing year, and brought under consideration at the next 
Meeting. 

The Committees shall recommend Reports on the state and 
progress of particular Sciences, to be drawn up from time to 
time by competent persons, for the information of the Annual 
Meetings. 


COMMITTEE OF RECOMMENDATIONS. 


The General Committee shall appoint at each Meeting a Com- 
mittee, which shall receive and consider the Recommendations 
of the Sectional Committees, and report to the General Com- 
mittee the measures which they would advise to be adopted for 
the advancement of Science. 


LOCAL COMMITTEES. 
Local Committees shall be formed by the Officers of the Asso- 
ciation to assist in making arrangements for the Meetings. 
Committees shall have the power of adding to their numbers 
those Members of the Association whose assistance they may 
desire. 


. OFFICERS. 


A President, two or more Vice-Presidents, one or more Se- 
cretaries, and a Treasurer, shall be annually appointed by the 
General Committee. 


COUNCIL. 


In the intervals of the Meetings, the affairs of the Association 
shall be managed by a Council appointed by the General Com- 
mittee. The Council may also assemble for the despatch of 
business during the week of the Meeting. 


PAPERS AND COMMUNICATIONS. 


The Author of any paper or communication shall be at liberty 
to reserve his right of property therein. 


ACCOUNTS. 


The Accounts of the Association shall be audited annually, by 
Auditors appointed by the Meeting. 


vill FIGHTH REPORT—1838. 


OFFICERS AND COUNCIL, 1838-9. 


——=>-— 


Trustees (permanent.)—R. 1. Murchison, Esq. John Tay- 
lor, Esq. 


President.—His Grace the Duke of Northumberland. 


Vice-Presidents.—The Bishop of Durham, F.R.S., F.A.S. 
Rey. W. Vernon Harcourt. Prideaux John Selby, Esq., F.R.S.E. 


President elect.—The Rev. William Vernon Harcourt, F.R.S. 


Vice-Presidents elect—Marquis Northampton, Pres. Royal 
Soc. Earl of Dartmouth. Rev. T. Robinson, D.D. John 
Corrie, Esq., F.R.S. 


General Secretaries—R. I. Murchison, Esq., F.R.S. Rev. 
G. Peacock, D.D., F.R.S. 


Assistant General Secretary.—Professor Phillips, Yorks. 


Secretaries for Birmingham.—George Barker, Esq. Joseph 
Hodgson, Esq. Follett Osler, Esq. Peyton Blakiston, M.D. 


General Treasurer.—John Taylor, Esq., 2, Duke Street, 
Adelphi. 


Treasurers to the Birminghum Meeting.—J. L. Moilliet, 
Esq. James Russell, Esq. 


Council.—Dr. Arnott. F. Baily, Esq. Rev. Dr. Buckland. 
R. Brown, Esq. The Earl of Burlington. Professor Clark. 
Dr. Daubeny. G. B. Greenough, Esq. Professor Graham. 
J. E. Gray, Esq. Robert Hutton, Esq. Rev. L. Jenyns. 
Sir Charles Lemon, Bart. Charles Lyell, Esq. J. W. Lubbock, 
Esq. Dr. Lardner. ProfessorOwen. SirJ.Rennie. Major 
Sabine. Colonel Sykes. Rev. Protessor Whewell. Professor 
Wheatstone. Captain Washington. 


Secretary to the Council_—James Yates, Esq., 49, Upper 
Bedford Place, London. 


Local Treasurers.—Dr. Daubeny, Oxford. Professor Hens- 
low, Cambridge. Dr. Orpen, Dublin. Charles Forbes, Esq., 
Edinburgh. William Gray, jun., Esq., York. William Sanders, 
Esq., Bristol. Samuel Turner, Esq., Liverpool. Rev. John 
James Tayler, Manchester. James Russell, Esq., Birmingham. 
William Hutton, Esq., Newcastle-on-Tyne. Henry Wool- 
combe, Esq., Plymouth. 


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x EIGHTH REPORT—1838. 


Il. Table showing the Members of Council of the British Association 
from its Commencement, in addition to Presidents, Vice-Presidents, 


and Local Secretaries. 


Rev. Wm. Vernon Harcourt, F.R.S., &c. 1832—1836. 
Pe] Nenrelavice Francis Baily, V.P. and Treas. B.S. .....-1835. 
S CTs CS NAR Pe Mnrchison, a lv.se, reo Mac ecaners 1836—1838. 
Rev. G. Peacock, F.R.S., F.G.S., &c. ...1837, 1838. 
General Treasurer. John Taylor, F.R.S., Treas. G.S., &. ...1832—1838. 
Charles Babbage, F.R.SS.L. & E., &c. (Resigned.) 


Trustees (permanent). | R. I. Murchison, F.R.S., &c. 
John Taylor, F.R.S., &c. 


ecnsincd? } Professor Phillips, F.R.S., &¢. ...eseseee ..1832—1838. 
Members of Council. 

G. B. Airy, F.R.S., Astronomer Royal ...... aoe 1835. 
Neill Arnott, M.D. ......ccsseceecsecereeeeeerees 1838. 
Francis Baily, V.P. and Treas. R.S. ........- 1837, 1838. 
George Bentham, F.L.S. ......sseesesesseeeeeess 1834, 1835. 
Robert Brown, D.C.L., F.R.S. ...seeeeeeeees 1832, 1834, 1835, 1838. 
Sir David Brewster, F. R. S.5 Sieieaceeceuctenese 1832. 
M. I. Brunel, F.R.S., &0.......0eeeseseeceeeeeens 1832. 
Rey. Professor Buckland, D.D., F.R.S., &c. 1833, 1835, 1838. 
The Earl of Burlington......-.esceeeeeeeeeeeeenes 1838. 
Rev. T. Chalmers, D.D., Prof. of Divinity, 

Edinburgh .........csecenseneeeeeseneeereeaes 1833. 
Professor Clark, Cambridge........ssssee05, e+ 1838. 
Professor Christie, F.R.S., , &c See eee pee taldnas 183383—1837. 
William Clift, F.R.S., F. Gis eae: 1832—1835. 
John Corrie, F. R.S., &e. aecanbddeedastes cme ces 6 1832. 
Professor Daniell, F. IR, Sacctcoe nese eeanmmarcenias 1836. 
Dr. Datbeny......sseseeeceenerereenceeneeterseenes 1838. 
J. E. Drinkwater .......0.ccscssseccecceteverecees 1834, 1835. 
The Earl Fitzwilliam, D.C.L., F.R.S., &c....1833 
Professor Forbes, F.R.SS.L. & E., &c......++- 1832 
Davies Gilbert, D.C.L., V.P.R.S., &c. «..... 1832 
Professor Graham, M.D., F.R.S.E.......02.0++ 1837. 
Professor Thomas Graham, F.R.S............- 1838. 
John Edward Gray, F.R.S., F.L.S., &c....... 1837, 18388 
Professor Green, F.R.S., F.G.S. .....ceeeeeeees 1832. 
G. B. Greenough, F.R.S., F.G.S. ......eeeee 1832—1838 
Henry Hallam, aR Ses B i: Aen Oc Cason caredews 1836. 
Sir William R. Hamilton, Astron. Royal of 

ireland. sees. cawsctecccsc-ceeaccseseocecenwuas 1832, 1833, 1836. 


Rev. Prof. Henslow, M.A., F.L.S., F.G.S....1837. 
Sir John F. W. Herschel, F.R.SS. L. & E., 


TRONS Let Cais er eecscasocnogs saeeueces 1832. 
Thomas Hodgkin, M. D. Rotts as maccasearins 1823—1837. 
Prof. Sir W. J. Hooker, LL.D., F.R.S., &c. 1832. 

Rev. F. W. Hope, M.A., F. TGs idee eee 1837. 
Robert Hutton, M.P., F. G. Si GlCserteessinane 1836, 1838. 
Professor R. Jameson, F.R. SS. Dyas Dee Sa o035 1833. 


Rey. Leonard Jenyns .........seceeeseeesevenees 1838. 


MEMBERS OF COUNCIL. xi 


Sir C. Lemon, Bart., M.P.  ........sceseeeeeeeee 1838. 

Bev. Dr. Lardner <*. 1c, -<asco-n sce oscaceercestess 1838. 

Professor Lindley, F.R.S., F.L.S., &c. ......+. 1833, 1836. 

Rev. Provost Lloyd, D.D. .........cceseceeeseenes 1832, 1833. 

J. W. Lubbock, F.R.S., F.L.S., &c., Vice- » 
Chancellor of the Univer sity of London 1838—1836, 1838. 

Rev. Thomas Luby be Set Soper bmaraen ac degeaaee 1832. 

Charles Lyell, jun., Esq. .......esceseerereoeeees 1838. 

William Sharp MacLeay, Jie! beatin nepaaaHagde 1837. 

Patrick Neill, LL.D., F.R.S.E..........0ceeeeees 1833. 

Richard Owen, F.R. S. as F, Ms STs .- 1836, 1838. 

Rev. George Peacock, M Ma F. R. s. 5 Be. seems "1832, 1834, 1835. 

Rev. Professor Powell, M.A., F.R.S., &c....... 1836, 1837. 

J.C. Prichard, M.D., F.R 2.5. EQ Gsccceveccwa cra 11832. 

George Rennie, INGLES SH, Gosunoancdecoacneeeagscpebe 1833—1835. 

Sir John Rennie............... caned seuss Sictpeaees 1838. 

Rev. Professor Ritchie, F.R.S. ........seeeeeeees 1833. 

Sir John Robison, Sec. R.S.E. ........seceeeeees 1832, 1836. 

P. M. Roget, M.D., Sec. R.S., F.G.S., &. ...1854—1837. 

iapan Sab iniey sce smetsares-ncosse=estnansateantouece 1838. 


Rey. William Scoresby, B.D., F.R.SS. L. & E. 1832. 
Lieut.-Col. W. H. Sykes, F.R.S., F.L.S., &....1837, 1838. 


Rev. J. J. Tayler, B.A., Manchester....... ee 1 832. 
eotessor Pratl MED. siecsecsesesoweraswccbece 1832, 1833. 
ING AS Vigors, M.P., D.C.L., ES.A, F.L.S....1832, 1836. 
Captain Washington, a Niacetentanttet negeasa sae ssion' 1838. 
Professor Wheatstone............ FpScaSuewdeedels tes 18388. 
leva WW. Wilrewell’ sc25,¢sntteccoresetsiseastres sere 1838. 


William Yarrell, F.L.S. .....ccccesecseees seeeeess,LS03—1836. 


Secretaries to the Edward Turner, M.D., F.R.SS. L. & E...1832—1836. 
Council. James Yates, F.R.S., F.L.S., F.G.S....... 1832—1838. 


xii EIGHTH REPORT—1838. 


OFFICERS OF SECTIONAL COMMITTEES AT THE 
NEWCASTLE MEETING. 


SECTION A.—MATHEMATICAL AND PHYSICAL SCIENCE. . 


President.—Sir J. F. W. Herschel, Bart., F.R.S. : 

Vice- Presidents. —Fraucis Baily, Esq., F.R.S. Sir D. Brew- 
ster, Knt. Sir W. R. Hamilton, Knt. Rev. D. Robinson. 

Secretaries.—Rev. Professor Chevalier. Major Sabine, F.R.S. 
Professor Stevelly. 


SECTION B.—CHEMISTRY AND MINERALOGY. 


President.—Rev. W. Whewell, F.R.S., P.G.S. 

Vice-Presidents.—Dr.T.Thomson. Dr. Daubeny. Professor 
Graham. 

Secretaries. — Professor Miller. H. L. Pattinson, Esq. 
Thomas Richardson, Esq. 


SECTION C.—GEOLOGY AND GEOGRAPHY™*. 


President for Geology.—C. Lyell, Esq., F.R.S., V-P.G.S., &c. 

President for Geography.—Lord Prudhoe. 

Vice-Presidents—W. Buckland, D.D., F.R.S., V.P.G.S. 
John Buddle, Esq., F.G.S. 

Secretaries for Geology.—W. C. Trevelyan, Ksq., ¥F.R.S.E., 
F.G.S. Captain Portlock, R.E., F.R.S., F.G.S. 

Secretaries for Geography.—Captain Washington, R.N. 


SECTION D.—ZOOLOGY AND BOTANY. 


President.—Sir W. Jardine, Bart. 

Vice-Presidents.—R. K. Greville, LL.D. Rev. L. Jenyns, 
F.L.S. Rev. F. W. Hope, F.R.S. 

Secretaries.—Jobn E. Gray, Esq., F.R.S. Professor Jones, 
F.R.S. R. Owen, Esq., F.R.S. John Richardson, M.D., F.R.S. 


SECTION E.—MEDICAL SCIENCE, 


President.—T. E. Headlam, M.D. 

Vice-Presidents.—Professor William Clark, M.D., F.G.S. 
John Yelloly, M.D., F.R.S. John Fife, Esq. 

Secretaries.—T. M. Greenhow, Esq. J. R. W. Vose, M.D. 


_* By a resolution of the General Committee at the Newcastle Meeting, the 
title of this Section will in future be Geotocy anp Puysica, Geocrapuy. 


OFFICERS OF SECTIONAL COMMITTEES. xii 


SECTION F.—STATISTICS. 


President.—Col. Sykes, F.R.S., V.P. Statistical Society of 
London. 

Vice-Presidents.—Sir Charles Lemon, Bart., M.P., F.R.S. 
G. R. Porter, Esq. Charles W. Bigge, Esq. 

Secretaries.—James Heywood, Esq. W. R. Wood, Esq. 
Wm. Cargill, Esq. 


SECTION G.—MECHANICAL SCIENCE. 


President.—Charles Babbage, Esq., F.R.S., &c. &c. 

Vice-Presidents.—Bryan Donkin, Esq., V.P. Inst. C.E., &c. 
Sir John Robison, Sec. R.S.E. G. Stephenson, Esq. Pro- 
fessor Willis. 

Secretaries.—R, Hawthorn, Esq. T. Webster, Esq., Sec. 
Inst. C.E. C. Vignolles, Esq. 


CORRESPONDING MEMBERS. 


Professor Agassiz, Neufchatel. M. Arago, Secretary of the 
Institute, Paris. A. Bache, Principal of Girard College, Phi- 
ladelphia. Professor Berzelius, Stockholm. Professor De la 
Rive, Geneva. Professor Dumas, Paris. Professor Ehrenberg, 
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Liebig, Giessen. Professor Girsted, Copenhagen. Jean Plana, 
Astronomer Royal, Turin. M. Quetelet, Brussels. Professor 
Schumacher, Altona. 


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DESIDERATA, ETC. X¥ 
- 


The following Reports on the Progress and Desiderata of dif- 
ferent branches of Science have been drawn up at the request 
of the Association, and printed in its Transactions. 


Vout. I. 


On the progress of Astronomy during the present century, 
by G. B. Airy, M.A., Astronomer Royal. 

On the state of our knowledge respecting Tides, by J. W. 
Lubbock, M.A., Vice-President of the Royal Society. 

On the recent progress and present state of Meteorology, 
by James D. Forbes, F.R.S., Professor of Natural Philosophy, 
Edinburgh. 

On the present state of our knowledge of the Science of Ra- 
diant Heat, by the Rev. Baden Powell, M.A., F.R.S., Savilian 
Professor of Geometry, Oxford. 

On Thermo-electricity, by the Rev. James Cumming, M.A., 
E.R.S., Professor of Chemistry, Cambridge. 

On the recent progress of Optics, by Sir David Brewster, 
K.C.G., LL.D., F.R.S., &c. 

On the recent progress and present state of Mineralogy, by 
the Rev. William Whewell, M.A., F.R.S. 

On the progress, actual state, and ulterior prospects of 
Geology, by the Rev. William Conybeare, M.A., F.R.S., 
V.P.G.S., &c. 

Onthe recent progress and present state of Chemical Science, 
by J. F. W. Johnston, A.M., Professor of Chemistry, Durham. 

On the application of Philological and Physical researches to 
the History of the Human Species, by J. C. Prichard, M.D., 
F.R.S., &c. 

Vou. I. 


On the advances which have recently been made in certain 
branches of Analysis, by the Rev. G. Peacock, M.A.,F.R.S., &c. 

Onthe present state of the Analytical Theory of Hydrostatics 
and Hydrodynamics, by the Rev. John Challis, M.A., F.R.S., &c. 

On the state of our knowledge of Hydraulics, considered as a 
branch of Engineering, by George Rennie, F.R.S., &c. (Parts 
I. and II.) 

On the state of our knowledge respecting the Magnetism of 
the Earth, by 8S. H. Christie, M.A., F.R.S., Professor of Mathe- 
matics, Woolwich. 

On the state of our knowledge of the Strength of Materials, 
by Peter Barlow, F.R.S. 

On the state of our knowledge respecting Mineral Veins, by 


John Taylor, F.R.S., Treasurer G.S., &c. 


XV1 EIGHTH REPORT—1838. 


On the state of the Physiology of the Nervous System, by 
William Charles Henry, M.D. : 

Onthe recent progressof Physiological Botany, by John Lind- 
ley, F.R.S., Professor of Botany in the University of London. 


Vou. III. 

On the Geology of North America, by H. D. Rogers, F.G.S.° 

On the philosophy of Contagion, by W. Henry, M.D.,F.R.S. » 

On the state of Physiological Knowledge, by the Rev. Wm. 
Clark, M.D., F.G.S., Professor of Anatomy, Cambridge. 

On the state and progress of Zoology, by the Rev. Leonard 
Jenyns, M.A., F.L.S., &c. 

On the theories of Capillary Attraction, and of the Propaga- 
tion of Sound as affected by the Development of Heat, by the 
Rev. John Challis, M.A., F.R.S., &c. 

On the state of the science of Physical Optics, by the Rev. 
H. Lloyd, M.A., Professor of Natural Philosophy, Dublin. 


Vor. IV. 


On the state of our knowledge respecting the application of 
Mathematical and Dynamical principles to Magnetism, Electri- 
city, Heat, &c., by the Rev. Wm. Whewell, M.A., F.R.S. 

On Hansteen’s researches in Magnetism, by Captain Sabine, 
F.R.S. 

On the state of Mathematical and Physical Science in, Bel- 
gium, by M. Quetelet, Director of the Observatory, Brussels. 


Vou. V. 

On the present state of our knowledge with respect to Mine- 
ral and Thermal Waters, by Charles Daubeny, M.D., F.R.S., 
M.R.I.A., &c., Professor of Chemistry and of Botany, Oxford. 

On North American Zoology, by John Richardson, M.D., 
E.R.S., &c. 

Supplementary report on the Mathematical Theory of Fluids, 
by the Rev. J. Challis, Plumian Professor of Astronomy in the 
University of Cambridge. 

Vou. VI. 

On the variations of the Magnetic Intensity observed at dif- 
ferent points of the Earth’s Surface, by Major Edward Sabine, 
RA. EBS. 

On the various modes of Printing for the use of the Blind, 
by the Rev. William Taylor, F.R.S. 

On the present state of our knowledge in regard to Dimor- 
phous Bodies, by Professor Johnston, F.R.S. 

On the Statistics of the Four Collectorates of Dukhun, under 
the British Government, by Col. Sykes, F.R.S. 


<t ee 


i a ae 


DESIDERATA, ETC. Xvli 


The following Reports of Researches undertaken at the re- 


quest of the Association have been published, viz. 


Vot. IV. 


On the comparative measurement of the Aberdeen Standard 
Scale, by Francis Baily, Treasurer R.S., &c. 
On Impact upon Beams, by Eaton Hodgkinson. 
Observations on the Direction and Intensity of the Terrestrial 
Magnetic Force in Ireland, by the Rev. H. Lloyd, Capt. Sabine, 
and Capt. J. C. Ross. 
On the Phenomena usually referred to the Radiation of Heat, 
by H. Hudson, M.D. : 
Experiments on Rain at different elevations, by Wm. Gray, 
jun., and Professor Phillips. 
Hourly observations of the Thermometer at Plymouth, by 
W.S. Harris. : 
On the Infra-orbital Cavities in Deers and Antelopes, by A. 
Jacob, M.D. 
‘On the Effects of Acrid Poisons, by T. Hodgkin, M.D. 
On the Motions and Sounds of the Heart, by the Dublin Sub- 
Committee. 
On the Registration of Deaths, by the Edinburgh Sub-Com- 
mittee. 


Vou. V. 


Observations on the Direction and Intensity of the Terres- 
trial Magnetic Force in Scotland, by Major Edward Sabine, 
R.A., F.R.S., &c. 

Comparative view of the more remarkable Plants which cha- 
racterize the Neighbourhood of Dublin, the Neighbourhood of 
Edinburgh, and the South-west of Scotland, &c.; drawn up for 
the British Association, by J. T. Mackay, M.R.I.A., A.L.S., 
&c., assisted by Robert Graham, Esq., M.D., Professor of 
Botany in the University of Edinburgh. 

Report of the London Sub-Committee of the Medical Section 
of the British Association on the Motions and Sounds of the 
Heart. 

Second Report of the Dublin Sub-Committee on the Motions 
and Sounds of the Heart. (See Vol. iv. p. 243.) 

Report of the Dublin Committee on the Pathology of the 
Brain and Nervous System. 

Account of the recent Discussions of Observations of the 
Tides which have been obtained by means of the grant of money 
which was placed at the disposal of the Author for that purpose 
at the last Meeting of the Association, by J. W. Lubbock, Esq. 

b 


XVili EIGHTH REPORT—1838. 


Observations for determining the Refractive Indices for the 
Standard Rays of the Solar Spectrum in various media, by the 
Rev. Baden Powell, M.A., F.R.S., Savilian Professor of Geome- 
try in the University of Oxford. ' 

Provisional Report on the Communication between the Arte- 
ries and Absorbents on the part of the London Committee, by 
Dr. Hodgkin. : 

Report of Experiments on Subterranean Temperature, under ~ 
the direction of a Committee, consisting of Professor Forbes, 
Mr. W.S. Harris, Professor Powell, Lieut.-Colonel Sykes, and 
Professor Phillips (Reporter). 

Inquiry into the validity of a method recently proposed by 
George B. Jerrard, Esq., for Transforming and Resolving 
Equations of Elevated Degrees: undertaken at the request of 
the Association by Professor Sir W. R. Hamilton. 


Vot. VI. 


Account of the Discussions of Observations of the Tides 
which have been obtained by means of the grant of money which 
was placed at the disposal of the Author for that purpose at the 
last Meeting of the Association, by J. W. Lubbock, Esq., 
E.R.S. 

On the difference between the Composition of Cast Iron 
produced by the Cold and the Hot Blast, by Thomas 
Thomson, M.D., F.R.SS. L. & E., &c., Professor of Chemistry, 
Glasgow. 

On the Determination of the Constant of Nutation by the 
Greenwich Observations, made as commanded by the British 
Association, by the Rev. T. R. Robinson, D.D. 

On some Experiments on the Electricity of Metallic Veins, 
and the Temperature of Mines, by Robert Were Fox. 

Provisional Report of the Committee of the Medical Section 
of the British Association, appointed to investigate the Com- 
position of Secretions, and the Organs producing them. 

Report from the Committee for inquiring into the Analysis of 
a Glands, &c. of the Human Body, by G. O. Rees, M.D., 

GS. 

Second Report of the London Sub-Committee of the British 
Association Medical Section, on the Motions and Sounds of 
the Heart. 

Report from the Committee for making experiments on the 
Growth of Plants under Glass, and without any free communi- 
cation with the outward air, on the plan of Mr. N. I. Ward, 
of London. 

Report of the Committee on Waves, appointed by the British 


DESIDERATA, ETC. xix 


Association at Bristol in 1836, and consisting of Sir John Robi- 
son, K.H., Secretary of the Royal Society of Edinburgh, and 
John Scott Russell, Esq., M.A., F.R.S. Edin. (Reporter). 
On the relative Strength and other mechanical Properties of 
Cast Iron obtained by Hotand Cold Blast, by Eaton Hodgkinson. 
On the Strength and other Properties of Iron obtained from 
the Hot and Cold Blast, by W. Fairbairn. 


Vou. VII. 


Account of a Level Line, measured from the Bristol Channel 
to the English Channel, during the Year 1837-8, by Mr. 
Bunt, under the Direction of a Committee of the British As- 
sociation. Drawn up by the Rev. W. Whewell, F.R.S., one 
of the Committee. 

A Memoir on the Magnetic Isoclinal ‘and Isodynamic Lines 
in the British Islands, from Observations by Professors Hum- 
phrey Lloyd and John Phillips, Robert Were Fox, Esq., Cap- 
tain James Clark Ross, R.N., and Major Edward Sabine, 
R.A., by Major Edward Sabine, R.A., F.R.S. 

First Report on the Determination of the Mean Numerical 
Values of Railway Constants, by Dionysius Lardner, LL.D., 
F.R.S., &c. 

First Report upon Experiments, instituted at the request of 
the British Association, upon the Action of Sea and River 
Water, whether clear or foul, and at various temperatures, 
upon Cast and Wrought Iron, by Robert Mallet, M.R.LA., 
Ass. Ins. C.E. 

Notice of Experiments in progress, at the desire of the 
British Association, on the Action of a Heat of 212° Fahr., 
when long continued, on Inorganic and Organic Substances, 
by Robert Mallet, M.R.LA. 

Experiments on the ultimate Transverse Strength of Cast 
Tron made at Arigna Works, Co. Leitrim, Iréland, at Messrs. 
Bramah and Robinson’s, 29th May, 1837. 

Provisional Reports and Notices of Progress in Special Re- 
searches entrusted to Committees and Individuals. 


The following Reports and Continuations of Reports have been 
undertaken to be drawn up at the request of the Association. 


On the Connexion of Electricity and Magnetism, by S. H. 
Christie, Sec. R.S. 
b2 


XX EIGHTH REPORT—1838. 


On the state of knowledge of the Phenomena of Sound, by 
Rev. Robert Willis, M.A., F.R.S., &c. :, 

On the state of our knowledge respecting the relative level 
of Land and Sea, and the waste and extension of the land on 
the east coast of England, by R. Stevenson, Engineer to the 
Northern Lighthouses, Edinburgh. 

On circumstances in Vegetation influencing the Medicinal ~ 
Virtues of Plants, by R. Christison, M.D. 

On Salts, by Professor Graham, F.R.S. 

On the Differential and Integral Calculus, by Rev. Professor 
Peacock, M.A., F.R.S., &c. 

On the Geology of North America, by H. D. Rogers, F.G.S., 
Professor of Geology, Philadelphia. 

On the Mineral riches of Great Britain, by John Taylor, 
F.R.S., F.G.S. 

On Vision, by Professor C. Wheatstone, F.R.S. 

On the application of a General Principle in Dynamics to 
the Theory of the Moon, by Professor Sir W. Hamilton. 

On Isomeric Bodies, by Professor Liebig. 

On Organic Chemistry, by Professor Liebig. 

On Inorganic Chemistry, by Professor Johnston, F.R.S. 

On Fossil Reptiles, by Professor Owen, F.R.S. 

On the Salmonidz of Scotland, by Sir J. W. Jardine. 

On the Caprimulgidz, by N. Gould, F.L.S. 

On the state of Meteorology in the United States of North 
America, by A. Bache. 

On the state of Chemistry as bearing on Geology, by Pro- 
fessor Johnston. 

On Molluscous Animals and their Shells, by J. E. Gray, 
F.R.S. 

On Ornithology, by P. J. Selby, F.R.S.E. 

On the Specific Gravity of Steam, by a Committee, of which 
Mr. B. Donkin is Secretary. 

On the Geographical Distribution of Pulmoniferous Mol- 
lusca, by E. Forbes, F.L.S. 


Reports requested, Researches recommended, and Desiderata 
noticed by the Committees of Science at the Newcastle 
Meeting. 


REPORTS ON THE STATE OF SCIENCE. 


Prof. Bache, of Philadelphia, was requested to furnish a 
Report on the state of Meteorology in the United States, for 
the next meeting of the Association. 


DESIDERATA, ETC. XX1 


_ Prof. Johnston was requested to prepare a Report on the 
present state of Chemistry as bearing upon Geology. 

Mr. J. E. Gray, F.R.S., was requested to prepare a Report 
on the present state of our knowledge of Molluscous Animals 
and their Shells. 

Mr. Selby was requested to draw up a Report on the present 
state of knowledge of Ornithology, for an early meeting. 

Mr. Bryan Donkin (Secretary), Dr. Ure, Dr. Faraday, and 
Mr. Cooper were requested to Report as to the state of our 
knowledge on the Specific Gravity of Steam generated at differ- 
ent Temperatures ; Mr. Donkin to act as Secretary. 

Mr. K. Forbes was requested to Report on the present state 
of the knowledge of the Geographical Distribution of Pulmo- 
niferous Mollusca in Britain, and the circumstances which influ- 
ence this distribution. 

The Council were requested to apply for a Report on the 
present state and recent discoveries in Geology. 


Specific Researches in Science involving applications to 
Government or public bodies. 


MAGNETICAL OBSERVATIONS. 


Resolved,—1. That the British Association views with high in- 
terest the system of Simultaneous Magnetic Observations which 
have been for some time carrying on in Germany and in various 
parts of Europe, and the important results towards which they 
have already led; and that they consider it highly desirable 
that similar series of observations, to be regularly continued in 
correspondence with and in extension of these, should be insti- 
tuted in various parts of the British dominions. 

2. That this Association considers the following localities as 
particularly important : 


Canada, Van Diemen’s Land, 
Ceylon, ‘Mauritius, or the 
St. Helena, Cape of Good Hope ; 


and that they are willing to supply Instruments for the purpose 
of observation. 

3. That in these series of observations, the three elements of 
horizontal direction, dip, and intensity, or their theoretical 
equivalents, be insisted on, as also their hourly changes, and on 
appointed days their momentary fluctuations. 

4, That this Association views it as highly important that the 


XXxii EIGHTH REPORT—1838. 


deticiency yet existing in our knowledge of Terrestrial Magnet- 
ism in the Southern Hemisphere should be supplied by obser- 
vations of the magnetic direction and intensity, especially in the 
higher latitudes, between the meridians of New Holland and 
Cape Horn; and they desire strongly to recommend to Her 
Majesty’s Government the appointment of a naval expedition 
directed expressly to that object. ; 

5. That in the event of such expedition being undertaken, it 
would be desirable that the officer charged with its conduct should 
prosecute both branches of observations alluded to in Resolu- 
tion 3, so far as circumstances will permit. 

6. That it would be most desirable that the observations so 
performed, both in the fixed stations and in the course of the 
expedition, should be communicated to Prof. Lloyd. 

7. That Sir John Herschel, Mr. Whewell, Mr. Peacock, and 
Prof. Lloyd be appointed a Committee to represent to Govern- 
ment these recommendations. 

8. That the same gentlemen be empowered to act as a Com- 
mittee, with power to add to their number, for the purpose of 
drawing up plans of Scientific cooperation, &c. &c., relating to 
the subject, and reporting to the Association. 

9. That the sum of 400/. be placed at the disposal of the 
above-named Committee, for the purposes above mentioned*. 


ASTRONOMY. 


Sir J. Herschel and Mr. Baily were requested to make 
application to Government for increase in the instrumental 
power of the Royal Observatory at the Cape of Good Hope, and 
the addition of at least one assistant to that establishment. 


SCIENTIFIC RESEARCHES IN INDIA. 


Resolved,—1. That the British Association regard the mea- 
surement of an arc of longitude in India comparable in extent 
to the meridional are already measured in that country, as a 
most important contribution to other facts illustrative of the 
earth’s true figure, and, by a necessary consequence, 4o the pro- 
gress of astronomy. 

2. That the verification and comparison of the standards of the 
Indian and English surveys, as compared with the proposed 
Parliamentary standard, is indispensable to the correct know- 
ledge of the meridional and parallel ares. 


* The application to Government on this subject has been successful, the 


command of an expedition to the Antarctic regions being entrusted to Capt. 
J.C. Ross. 


DESIDERATA, ETC. xxiii 


3. That pendulum observations at the principal elevations, or 
contiguous plains, and on the sea-coast, if possible, on the same 
parallels of latitude, will afford results of great value to physical 
science. 

4. That observations for the determination of the Laws of Re- 
fraction in the elevated regions of the Himalayas, and at the 
Observatories of Madras and Bombay, will be a most important 
service to science. 

5. That itis highly desirable also that magnetical observations 


should be made in India similar to those which are carrying on 
in other parts of the world, and which are justly regarded with 
so much interest. 

6. That a topographical map of India, upon a large scale, ac- 
companied by statistical and geological information, would be 


highly desirable *. 


ORDNANCE SURVEY. 


Resolved,—That a Committee be appointed to inquire how 
far, in the future progress of the Ordnance Survey, the several 
metalliferous and coal-mining districts could be represented on 
a larger scale. The Committee to consist of Mr. Greenough, 
Mr. Griffith, Mr. De la Beche, and Major Portlock. 


MINING RECORDS. 


Resolved,—1l. That it is the opinion of this Meeting, that, 
with a view to prevent the loss of life and of property which 
must inevitably ensue from the want of accurate mining records, 
+t is a matter of national importance that a depository should 
be established for preserving such records of subterranean ope- 
rations in collieries and other mining districts. 

9. That a Committee be appointed to draw up a Memorial 
and to communicate with the Government in the name of the 
British Association, respecting the most effectual method of 
carrying the above resolution into effect. 

3° That the Committee consist of the following gentlemen, 
with power to add to their number : The Marquis of Northamp- 
ton, Sir Charles Lemon, Sir Philip Egerton, John Vivian, Esq., 
Davies G. Gilbert, Esq., J. S. Enys, Esq., W. L. Dillwyn, the 
President of the Geological Section of the British Association, the 
President for the time being of the Geological Society of Lon- 


* These Resolutions have been submitted to the consideration of the Di- 
rectors of the East India Company ; and, in particular, the recommendation 
for magnetical observations has been promptly acceded to. 


XXIV EIGHTH REPORT—1838. 


don, the Professors of Geology at Oxford, Cambridge, London, 
and Durham, H. T. De la Beche, Esq., John Taylor, Esq., John 
Buddle, Esq., Thomas Sopwith, Esq. 


Specific Researches in Science involving Grants of Money. 


The following new Recommendations were adopted by the 
General Committee*. 

That it is desirable that the meteorological observations made 
at the equinoxes and solstices, agreeably to the recommenda- 
tions of Sir John Herschel, Bart., should be collected together, 
as far as is practicable, and reduced to an uniform mode of ex- 
pression, so that comparisons may be made of the same, with a 
view of deducing results that may lead to the improvement and 
elucidation of meteorology. 

That Sir John Herschel be requested to superintend the same, 
and that the sum of 100/. be placed at his disposal for that 
purpose. 

That it is desirable that the whole of the stars observed by 
Lacaille at the Cape of Good Hope, the observations of which 
are recorded in his Celum Australe Stelliferum, should be re- 
duced. 

That Sir J. Herschel, Mr. Airy, and Mr. Henderson be a 
Committee for carrying the same into effect. 

That the sum of 200/. be appropriated to that purpose. 

That it is desirable that a Revision of the Nomenclature of 
the Stars should be made, with a view to ascertain whether or 
not a more correct distribution of them amongst the present 
constellations, or such other constellations as it may be con- 
sidered advisable to adopt, may be formed. 

That Sir J. Herschel, Mr. Whewell, and Mr. Baily be a 
Committee for that purpose, and to report on the same at the 
next meeting of the Association. 

That the sum of 50l. be appropriated to defray the expenses 
that may be incurred in this inquiry. 

That 100/. be placed at the disposal of Sir D. Brewster 
and Professor Forbes, for the purpose of procuring Hourly 
Meteorological Observations, to be made at two parts in Scot- 
land, one at Fort George, on the coast, and the other at some 
central part, at a great elevation above the sea. 

That it appears to the Committee desirable to diffuse in this 


* For a general synopsis of money grants sanctioned at the Newcastle 
Meeting, see p. xxvii. 


DESIDERATA, ETC. XXV 


country the knowledge of the Scientific Memoirs published on 
the Continent, and that, for this object, 100/. be placed at the 
disposal of a Committee, consisting of Dr. Robinson, Sir John 
Herschel, Sir D. Brewster, and Professor Wheatstone, with power 
to add to their number, towards procuring the translation and 
publication of such memoirs as they may approve. 

That Mr. Pattinson and Mr. Richardson be requested to un- 
dertake experiments to ascertain whether any perceptible Gal- 
vanic influence is exerted by the Stratified Rocks of the neigh- 
bourhood of Newcastle, and that 20/. be placed at their disposal 
to meet the expenses of such experiments. 

That Dr. Arnott and Dr. Yelloly be a Committee for the 
purpose of improving Acoustic Instruments (in reference to dis- 
eases of the ear), with 25/. at their disposal. 

That Mr. Cargill, Mr. Wharton, Mr. Buddle, Mr. Forster, 
Professor Johnston, and Mr. Wilson be a Committee for in- 
quiries into the Statistics of the Collieries of the Tyne and Wear, 
with 50/. at their disposal. 

That Sir John Robison (Secretary), and Mr. J. S. Russell, 
and Mr. James Smith be a Committee for instituting Experi- 
ments on the Forms of Vessels, with 200/. at their disposal. 


Researches not involving Grants of Money or application 
to Government. 


The Meteorological Committee was requested to furnish a 
System of Meteorological Instructions for the next meeting of 
the Association. 

A Committee was formed, consisting of Mr. Greenough, 
Mr. De la Beche, Mr. Buddle, and Mr. Griffith, to draw up a 
proper form and scale of the Sections to be sent to the Geolo- 
gical Society by the engineers and proprietors of railways. 

The following gentlemen were appointed a Committee to in- 
vestigate the Salmonide of Scotland, and directed to place them- 
selves in communication with Mr. Shaw, who has offered to 
submit his experiments on that subject to their inspection: 
Mr. Selby, Dr. Parnell, Mr. J.S. Menteith, Professor R. Jones, 
Dr. Neill, Sir W. Jardine, Bart., Secretary. 

The following gentlemen were appointed members of a Com- 
mittee constituted for the purpose of investigating the Insects 
of the genera Eriosoma and Aphis, which attack the Pines of 
this country: Mr. Spence, F.R.S., R. K. Greville, LL.D., Sir 
W. Jardine, Bart., Mr. Selby, Secretary. 


XXxvi EIGHTH REPORT—1838. 


The Committee on Diseases of the Lungs in Animals was 
reappointed. S 

The Committee for obtaining a complete account of the 
Fauna of Ireland was altered so as to consist of Capt. Portlock, 
Mr. R. Ball, Mr. W. Thompson, Mr. Vigors, Mr. Halliday, an 
Dr. Coulter, who was requested to act as Secretary. 


The following Resolutions relating to the Conduct of the 
Meetings, &c. were adopted by the General Committee. 


That Section C. be styled henceforth the Section of Geology 
and Physical Geography. 

That the several Sections be empowered, at the desire of 
their respective Committees, to divide themselves into sub- 
sections as often as the number and importance of the commu- 
nications delivered in may render such divisions desirable. 

That with a view to facilitate and extend the intercourse of 
persons engaged in investigating the same departments of 
science, the rooms in which the Sections are appointed to be 
held be open in future at 10 o’clock, vice 11, so that an hour 
may be allowed for conversation before the Chair is taken and 
the reading of papers is commenced. 

That Members of the Association, when subscribing: their 
name and address, be invited or enabled to enter also in a se- 
parate column the Section to which they wish to attach them- 


selves. 


SYNOPSIS. 


XXVil 


Synopsis of Sums appropriated to Scientific Objects by the 
General Committee at the Newcastle Meeting. 


Section A. 


* 1. For the Reduction of Meteorological Observa- 
tions, under the superintendence of Sir J. 
Herschel. . . : 

* 2. For the Reduction oe Tocnaile s Stars, under ‘the 
superintendence of Sir J. Herschel, Mr. Airy, 
and Mr. Henderson . 

* 3. For the Revision of the Nomenclature ‘of ‘the 
Stars: Sir John Herschel, Mr. Whewell, and 
Mr. Baily. 

4. For a Level Line from the Bristol to the English 
Channel, (an additional grant): Mr. Whewell, 
Col. Colby, Mr. Greenough, and Mr. Griffith 

. For Tide Discussions: Mr. Whewell . Or: 

. For the Reduction of Stars in the Histoire Cé- 

leste: Mr. Baily, Mr. Airy, and Dr. Robinson 

. To extend the Royal Astronomical Society’s Cata- 

logue: Mr. Baily, Mr. Airy, and Dr. Robinson 

- For Magnetical Observations, (Instruments, 

&c.): Sir J. Herschel, Mr. Whewell, Mr. 

Peacock, and Mr. Lloyd ....... 

9. To the Committee on Waves: Sir J. Robison 
and Mr. J. 8S. Russell. . . 

*10. For the Translation of Foreign Scientific Me- 
moirs: Dr. Robinson, Sir J. Herschel, Sir 
D. Brewster, and Prof. Wheatstone . . 

11. For Tabulating Meteorological Observations : 
Mr. Harris and Mr. Osler. . . . . 

12. To complete the Repair of an Anemometer at 
Plymouth: Mr. Osler 

13. For the Expenses of the Ce Obser- 
vations at Plymouth (additional Bran): Mr. 
W.S. Harris. . . 

*14, Hourly Meteorological Observations: Sir D. 
Brewster and Mr. Forbes . .... - 


ao mt on 


£100 


50 


40 


100 


Co Oo 8°90 


i) 


0) 


£2263 10 


XXVili EIGHTH REPORT— 1838. 


15. 


16. 
17. 


18. 
~19, 


23. 


SecTIon B. 

For Researches on Atmospheric Air: Mr. W. 

Wiest) Guie.nere .£ 40 
For Experiments on die ACHin of Sen Water on 

Cast and Wrought Iron: Mr, Mallet and Prof. 

Davy. . 50 
For Experiments on the Action of Water of 219° 

on Organic Matter: Mr. Mallet. . . . . 10 
For Chemical Constants: Prof. Johnston . . 30 


For Galvanic Experiments on Rocks in vicinity 

of Newcastle: Mr. Pattinson and Mr. Ri- 

GHArdsoW  Saceeee teas a ee eg Pa eee ee) 
£150 


SecTion C. 


. For the Promotion of Fossil Ichthyology: Dr. 


Buckland, Mr. Murchison, and Prof. Sedg- 
wick 3": + ah) ee OS 


. For Researeliens on ie Mud ue Rivers’: Mr. 


Bryce and Mr. De la Beche . 20 


. For the Promotion of our Knowledge bf Bhigiol 


Fossil Reptiles, by a Report on that subject : : 
Mr. Greenough, Mr. Lyell, and Mr. Clift . 200 


£325 


Secrion D. 
For Experiments on the Preservation of Animal 


and Vegetable Substances, Prof. Henslow, Mr. 
Jenyns, Dr. Clark, and Prof. Cumming . . £6 


Section E. 


. For Experiments on the Sounds of the Heart: 


Dr. Roget, Dr. Le and Dr. Dodd, &c. 
Gens po £50 


shor Experiments on the ‘Lungs and ‘Bronchi: 


Dr. Williams ; . 25 


. For Experiments on Medico-Acoustic Instru- 


ments: Dr. Arnott and Dr. Yelloly . . . 25 


£100 


Soy FSy aS 


a7. 


28. 


*29 


30. 


31. 


32. 


 *33, 


34. 


35. 


36. 
37. 


SYNOPSIS. XX1X- 


SEcTION F. 


Inquiries into the State of Education in Schools 

in England: Col. Sykes, Sir C. Lemon, and 

Mr. G. R. Porter. . oe ep. 
Inquiries as to the State of the Working Popu- 

lation: Sir C. Lemon, Col. Sykes, and Mr. 

G. RB. Porter-.. - 100 0 


. Inquiries into the Statistics of the Collicries of 


the Tyne and Wear: Mr. Cargill, Mr. Wharton, 
Mr. Buddle, Mr. Free Prof. Sy gn? and 
Mr. Wilson. . Bibi was eR Be 


Srcrion G. £300 O 


Researches in the duty performed by the Cornish 

Engines: Mr. John Taylor and Mr. Rennie . £50 0 
For Inquiries into the Speed of American 

Steamers: Mr. W. Fairbairn, Dr. Lardner, 

Mr. J. S. Russell, and Mr. John Taylor . . 50 O 
For a Report on the Duty and Engines not in 

Cornwall: Mr. W. Bryan Donkin, Mr. James 

Simpson, Mr. G. H. Palmer, and Mr. T. 

Webster, Sec... 4 450" O 
For Experiments on the Forms of Vessels: Sif 

J. Robison, Mr. J. S. Russell, and Mr. James 

Smm@thy) ty 43h) ak - 200 O 
For Experiments on the Hot- ‘blast Tron as com- 

pared with Cold-blast Iron : Mr. Hodgkinson, 

Mr. W. Fairbairn, and Mr. P. Clare, Sec. . 100 O 
For Railway Constants: Mr. H. Earle, Dr. 

Lardner, Mr. abhi Mr. Rennie, and Mr. 

MacNeil... «i. 20 O 
For Apparatus used in Researches regarding Ma- 

rine Steam Engines: Mr. J. Scott Russell . 17 O 
For completing an Instrument for Investigating 

the Duty of Marine Steam Engines: Dr. Lard- 

ner, £50, Mr. Russell, £28, and Mr. W. Fair- 


bairn, £33. asd etna F 2 i eh O 
Section A.) Saves. oie 10 (0) 
— Bo; 4 150 O O 
— Cus 325 0 O 
— Ds oe eG oO 'O 
— I Dbiee A 100 O O 
— Behe 300 O O 
— G:. 598 O O 


£3742 10 


o 


XXX EIGHTH REPORT—1838. 


The above grants expire at the Meeting in 1839, unless the 
Recommendations shall have been acted on, or.a continuance of 
the grant applied for by the Sectional Committees, and ordered 
by the General Committee. Those marked thus *, relate to 
subjects on which no previous resolution has been adopted : 
the grounds for such new grants will be found in the previous 
pages. The mark ¢ is affixed to grants for objects previously 
recommended by the Association, but without grants of money. 
The others are renewals or continuations of former grants for 
objects which have been detailed in previous volumes. 

In grants of money to Committees for purposes of Science, 
the member first named is empowered to draw on the Treasurer 
for such sums as may from time to time be required. The 
General Committee does not contemplate, in the grants, the 
payment of personal expenses to the members. 


Arrangement of the General Evening Meetings. 


On Monday evening, August 20, the President, His Grace 
the Duke of Northumberland, having taken the Chair in the 
Central Exchange, the Appress of the General Secretaries 
was read by R. I. Murchison, Esq. : 

On Tuesday evening, in the same room, the attention of the 
Meeting was called to the collection of Models in the Exhibition 
Room, and addresses, explanatory of particular INVENTIONS or 
ProcxssEs, were delivered by C. Babbage, Esq., the Rev. Dr. 
Robinson, and Professor Willis. 

On Wednesday evening, the Green Market, fitted up for the 
purpose, was opened for Promenade and Conversation, and 
Mr. Addams explained and exemplified the process by which 
the SottpiFICcATION OF Carsonic Acip Gas is effected. 

On Thursday evening, Abstracts of the Proceedings which 
had taken place in the Sections were read by the Presidents of 
the Sections in the Central Exchange. 

On Friday evening, the Assembly Rooms, enlarged for the 
occasion, were opened for Promenade and Conversation. 

On Saturday evening, the ConcLupING GENERAL MEETING 
of the Association took place in the Central Exchange, when 
an account of the PRocEEDINGS OF THE GENERAL COMMITTEE 
was read by the Rev. Professor Peacock. 


ADDRESS 


BY 


MR. MURCHISON. 


GENTLEMEN,—At the conclusion of the first Septenary which has 
elapsed since the establishment of the British Association, the. Council 
have deemed it expedient to direct us to prepare a general and com- 
prehensive view of its past progress and future prospects. In virtue, 
therefore, of the commission thus entrusted to us, we shall endeavour 
‘to perform a task which we cannot approach without a feeling of ap- 
prehension and anxiety, impressed as we are with the difficulty of duly 
appreciating the prominent labours of our associates, and of estimating 
their bearing and probable influence on the advancement of science. 
The space of time, however, which is allotted to this address, will not 
allow us to attempt an analysis of all the past proceedings of the As- 
sociation. We are therefore compelled to confine ourselves to a few 
allusions to the reports of former meetings, (dwelling more particularly 
on the last,) and to a statement of the great principles which form the 
basis of our constitution, and which have directed and regulated its 
practical operations. And if, in thus stating the aims of the Asso- 
ciation, and the principles on which it proceeds, we should be guilty of 
repeating some things which have been better said before, we trust it 
_ will be borne in mind, that from the migratory character of our meet- 
ings, and the change which that character implies in the body of mem- 
bers present at each, a probability arises, that those principles may 
not be sufficiently understood, if they are not from time to time re- 
stated and re-explained. 

It would be superfluous for us to speak of those objects of the As- 
sociation which are the most obvious, and which undoubtedly con- 
stitute the highest enjoyment these meetings afford us—the union of 
congenial minds—the mutual communication, without let or hindrance, 
of the knowledge we have acquired in our respective pursuits—the 
scintillations of new ideas struck out in private conversation and pub- 
lic discussion. “ This feast of reason and this flow of soul,” agreeable 
and instructive as it is, requires no comment; and though it contri- 
butes most essentially to all the purposes for which we are assembled, 
and gives life to all our proceedings, it is however on no account to be 
regarded as the chief aim and business of our meetings. That which 


XXxil EIGHTH REPORT—1838. 


has, from the first, gentlemen, been laid down as the highest object for 
which we meet, is to supply the great defect under-which science has 
formerly laboured, of depending solely on individual and insulated 
efforts, by combining its cultivators into a body politic, calculated to 
give force and consistence to those efforts, and exercise a powerful 
influence both on its own members and on the public mind; thus 
marshulling a scattered militia into an organized and effective army,. 
and converting desultory incursions into a regular and progressive 
march. The want of some such public authority in matters of science 
as belongs to an union like the present, could not be more strikingly 
shown than by the service which, on two occasions, the British Asso- 
ciation has rendered to astronomy, in obtaining from Government the 
means of effecting the laborious and expensive reductions of the obser- 
vations, first of the planets, and lastly of the moon, which had been 
made by Bradley, Maskelyne, and Pond. The existence and liberal 
support of the noble establishment at which these observations were 
made, bore evidence that our rulers have not been insensible to the 
immense importance of astronomical inquiries to a great maritime 
nation; but that so much of the precious ore which had been accu- 
mulated during the greater part of a century, by the successive labours 
of the greatest practical astronomers of any age or nation, should have 
remained unwrought and nearly useless for the highest applications of 
science, amidst the vain and oft-repeated regrets of those who were 
the most competent judges of its value,—what does this prove, but that 
there were no councillors of sufficient weight, number, or influence, 
not only to offer advice to the Government, but also to secure attention 
to it when offered ? 

In whatever degree the practical value of science may be beginning 
to be understood and appreciated among us, business of more proxi- 
mate interest and more obvious urgency engrosses the attention of our 
public functionaries and legislators: numerous projects are presented 
to them rarely reduced to a practical form, among which they know 
not how to distinguish which are, and which are not deserving of na- 
tional encouragement; and the consequence has been, with few ex- 
ceptions, the general discouragement of all,—a consequence neither 
conducive to the reputation, nor serviceable to the interests of so great 
acountry. But a representation on subjects of science proceeding from 
such an Association as this bears a public character, and carries with it 
a degree of weight which does not, and ought not, to attach to indivi- 
dual applications ; and as long as the same judgement and forbearance 
which have hitherto characterized its course in this respect shall con- 
tinue to be exercised,—as long as special care is taken to ask nothing 
of Government but what it belongs to the national interests or honour 
to effect, and what cannot be effected *but by national means,—so long 


ADDRESS BY MR. MURCHISON. Xxxlil 


doubtless that attention will be paid to our recommendations which they 
have already begun to receive. Wisely cautious and reserved in exerting 
its influence, the Association has hitherto made but few applications to 
the government. Besides those to which we have before referred, and 
which were immediately complied with, another was made regarding 
the slow progress of the trigonometrical surveys of England and Scot- 
land: the latter probably owes its recent acceleration to the attention 
thus first drawn to the subject, subsequently reinforced by a deputation 
from the Royal Society of Scotland; but the survey of England, 
which, having commenced nearly half a century ago, has not yet 
reached the Trent, is still in abeyance; and these northern districts in 
which we are assembled, and which comprise so large a part of the 
staple riches of the country, continue without their due share of the 
advantages which would attend its execution. There have been like- 
wise two other national objects on which the Association has expressed 
its opinion; the one being the establishment of a magnetical observa- 
tory in Great Britain, the other an expedition for the purpose of making 
magnetical observations in the Antarctic seas. For the attainment of 
the former of these objects no interference was found necessary, an 
arrangement every way satisfactory being determined upon for con- 
necting it with the Royal Observatory at Greenwich, on the recommen- 
dation of the Board of Visitors. The publication, in the present volume 
of our Transactions, of an elaborate report on the variations of the mag- 
netic intensity of the earth, (unquestionably one of the most valuable 
which has hitherto appeared in them, whether we consider the labo~ 
rious reductions it has required, or the important conclusions to which 
they lead,) recals our attention to the latter point. The subject is one 
of such deep interest, that we hope we shall not be thought to trespass 
too much on the time of the meeting, if we repeat some of Major 
Sabine’s remarks upon it in his own words :— 

“JT have already adverted to what the influence of the Association 
may effect, in causing the spaces yet vacant on the map, in the British 
possessions in India and Canada, to be filled. But beyond all compa- 

_rison, the most important service of this kind, which this or any other 
country could render to this branch of science, would be by filling the 
void still existing in the southern hemisphere, and particularly in the 
vicinity of those parts of that hemisphere which are of principal mag- 
netic interest. This can only be accomplished by a naval voyage; for 
which it is natural that other countries should look to England. That 
the nations that have made exertions in the same cause do look to 
England for it, cannot be better shown than by the following extract 
of a letter of M. Hansteen’s, which I take the liberty of introducing 
here, both for this purpose, and because it expresses in so pleasing a 
manner the praise that is so justly due to his own country, and which 

¢ 


XXXIV EIGHTH REPORT—1838. 


I am sure will be cordially responded to by all who cultivate science 
in this country, and particularly by those who know the kindly feeling 
with which Englishmen are ever welcomed in Norway. 

“ C’est le Storthing (la Chambre des Députés) de la Norvége, qui a 
donné les frais 4 l’expédition en Sibérie. On a fait cela dans un tems 
ou on a refusé les dépenses pour un chateau de résidence pour sa 


Majesté 4 Christiania. Dans un tems, ot une telle économie a éte’ 
nécessaire, il est tres honorable, qu'une Chambre, composée de toutes’ 


les classes du peuple, méme d’un grand nombre de paysans, a una- 
nimement résolu de donner les frais pour une expédition purement 
scientifique, dont les résultats n’auront jamais aucune utilité écono- 
mique pour la patrie, et dont on ne comprenait pas la haute valeur 
scientifique. Regardé les ressources trés-bornés de notre pays, c’est 
une générosité presque sans exemple. 

“ Comme la petite Norvége a fourni toutes les observations entre les 
méridiens de Greenwich et de Ochozk, et entre les paralléles de 40° et 
75° de latitude boréale, il ne me semble pas une demande trop grande 
ou immodeste 4] Angleterre, si grande, si riche, si puissante, qui a 
nécessairement un plus grand intérét dans toutes les sciences combinées 
avec la navigation, de fournir toute la partie méridionale de la carte. 
Une telle entreprise doit réfléchir une splendeur 4 la nation, et payera 
a la fin les frais par des résultats aussi utiles pour les sciences que pour 
la navigation. II ne faut plus dans notre tems laisser l’avancement des 
sciences au hasard. Par des observations fragmentaires et discontinués 
on a taché avec grande peine d’étudier les phénoménes magnétiques de 
la terre pendant deux ou trois siécles. Par deux ou trois expéditions 
arrangées exprés pour ce but, on pourrait en peu d’années avoir une 
collection plus compléte, et d’une plus grande utilité pour la théorie.” 

The subject has in every way a claim on this country. The existence 
of four governing centres, and the system of the phenomena in corre- 
spondence therewith, was originally a British discovery. The sagacity 
of our countryman Halley was the first to penetrate through the com- 
plexity of the phenomena, and to discern what is now becoming gene- 
rally recognised. England was also the first country which sent an 
expedition expressly for magnetic observation, namely, that of Halley 
in 1698 and 1699. Whilst approving and cordially co-operating in 
magnetic inquiries of other kinds which have their origin in other 
countries, it is right that we should feel a peculiar interest in that in 
which we have ourselves led the way, especially when its object is 
subordinate to none. As the research would require to be prosecuted 
in the high latitudes, a familiarity with the navigation of such latitudes 
would be important in the person who should undertake this service ; 
and a strong individual interest in the subject itself would be of course 
a most valuable qualification, I need scarcely say, that the country 


—— 


OS Ss ee 


- 


ADDRESS BY MR. MURCHISON. XXXV 


possesses a naval officer* in whom these qualifications unite in a 
remarkable degree with all others that are requisite; and if fitting in- 
struments make fitting times, none surely can be better than the pre- 
sent. Viewed in itself and in its various relations, the magnetism of 
the earth cannot be counted less than one of the most important 
branches of the physical history of the planet we inhabit; and we may 
feel quite assured, that the completion of our knowledge of its distri- 
bution on the surface of the earth would be regarded by our contem- 
poraries and by posterity as a fitting enterprise of a maritime people, 
and a worthy achievement of a nation which has ever sought to rank 
foremost in every arduous and honourable undertaking. 

The course pursued by the Association in reference to this object is 
well calculated to show the system of its operations, and the active but 
yet unintrusive and guarded spirit in which it prosecutes its aims. It 
was proposed at one of our meetings by the Committee of the Physical 
Section, that a representation should be made to government of the 
advantage which would accrue to science from an expedition to the 
Southern Ocean, devoted to the purpose chiefly of instituting mag- 
netical observations. This proposal first underwent the revision of the 
Committee of Recommendations, and then obtained the sanction of 
the General Committee of scientific members; subsequent cireum- 
stances, however, being considered by the Council as unfavourable to 
the success of the application, it was not urged at that time upon the 
government, yet the object was not lost sight of. The Association 
next procured reports to be drawn up, (from one of which we have 
quoted the foregoing paragraph,) presenting a luminous exposition, 
both from published and unpublished sources, of the present state of 
our knowledge of the magnetism of the earth, and of the reasons which 
there are for wishing to extend to the Southern hemisphere those re- 
searches which in the Northern have led to such important conclu- 
sions; and thus has the way been prepared through information thus 
communicated to the public for pursuing the intended course with 
advantage, and making a more effectual application to the government. 
There may be, once in an age, or in many ages, an individual ani- 
mated by so lofty an ardour for the advancement of a favourite branch 
of knowledge, as to engage, at his own cost, in an enterprise (like a 
recent survey of the southern skies) which it might have become a 
nation to take upon itself; and there may be an individual whose dis- 
interested munificence may extend to the point of rendering labours of 
this magnitude as available to the public as if the state itself had con- 
tributed its aid; but such sacrifices to science are not only uncommon, 
they are in general impracticable; and there are numerous most im- 
portant data and elements for philosophical reasoning, with all its 


* Capt. James Ross, R. N. 
c2 


XXXVi EIGHTIE REPORT—1838. 


train of practical utilities, which individuals cannot be expected to 
undertake, unless provided with pecuniary assistance. We have al- 
ready said, that one of the principles on which the’ Association pro- 
ceeds, is not to look to government for anything which can be other- 
wise attained; but when this Institution was established, the founders 
of it foresaw that it might itself be made applicable, in a great degree, 
to the object of supplying funds for such undertakings. The resources 
of other societies are employed on their publications or collections ; 
and it}is one of the rules of the German scientific “ Reunions,” that 
they shall possess no property. Our objects were more extensive than 
theirs, and, therefore, our plan was different. We have accumulated 
property and expended it, to give wings to investigation, partly by 
providing instruments and materials for carrying on certain determi- 
nate inquiries, and partly in defraying the expense of labour, especially 
labour of that kind, which, whilst it is of the highest value in its re- 
sults, possesses no attractions in its execution, and would meet with no 
adequate remuneration. 

The present volume of our Transactions contains many proofs of 
the service which the Association has rendered by such applications of 
its pecuniary means. In the account there rendered of the discussion 
of observations of the Tides, Mr. Lubbock (the Reporter) thus ex- 
plains the manner in which the last grant of money placed at his dis- 
posal has been employed. He reports that two gentlemen had been 
engaged by him to discuss the observations which had been accumu- 
lated at Liverpool and the London Docks,—the one series continued 
during nineteen years, and consisting of 13,391 observations, the 
other carried on for thirty-five years, and including 24,592 obser- 
vations,—and also to examine carefully the establishment and average 
height of high water in order to ascertain the fluctuation to which these 
quantities are subject; and after bearing testimony to the pains and 
accuracy with which the work has been executed, and stating the 
conclusions which result from these laborious calculations, adds, that 
“they never could have been undertaken but for the interest which 
has been felt on the subject by some of the most distinguished mem- 
bers of the Association, and but for the pecuniary grants which have 
at different times been devoted to this object,” expressing, at the same 
time, 2 well-grounded hope “ that when these results (which have since 
been published in the Philosophical Transactions) are carefully ex- 
amined, they will not be found disproportionate in value to the great 
labour and expense which have been required for their attainment.” 
A service of a similar description has been rendered to astronomy in 
the determination, by Dr, Robinson, of the disputed Constant of Nu- 
tation from the Greenwich Observations. Of this work, which in- 
yolves much labour of reduction, and which, to use the words of the 


| 


CY oe ee 


“4 


—— - 


ADDRESS BY MR. MURCHISON. XXXVIi 


eminent astronomer who executed it, the powerful aid of the Asso- 
ciation has enabled him to perform, a brief statement only, comprising 
the method employed and the general results, is given in our Trans- 
actions the fuller details requiring, as the author mentions, a different 
mode of publication. And this, Gentlemen, leads us to remark how 
unfounded were the apprehensions of those who feared that this In- 
stitution would divert the springs from which other societies are sup- 
plied; whereas the instances before us prove that their Transactions 
have been enriched instead of being impoverished by our operations. 
There is a further remark which we are prompted to make on the 
work accomplished under Mr. Lubbock’s superintendence, by a re- 
ference which his report contains to a subject of great interest to the 
science of Geology. “I conceive (he says) that the best, if not the 
only method of investigating alterations in the height of the land above 
the water, in any given locality where the water is influenced by the 
tides, will be to examine carefully whether any alteration has taken 
place in the value of the (tide) constants D and E for that place, the 
height of high water being, of course, always reckoned from some 
fixed mark in the land.” The meeting will here perceive one of those 
connexions between departments of inquiry apparently remote, which 
show how much each is concerned in the advancement of another, 
and ought to prevent any jealousy respecting the distribution and 
allotment of our funds. There is, indeed, no part of the proceedings 
of the Association which requires to be regarded with more care than 
the disposal of its grants, and our constitution has been framed with a 
particular regard to this point. In the first place, every section of 
science has its own committee, from whose deliberations every pro- 
posal of a grant must emanate. Secondly, these proposals are all 
submitted to a central committee, which recommends such of them as 
it deems unobjectionable to the General Committee for final adoption 
or rejection. By these means the best provision has been made for 
preserving the administration of our pecuniary resources pure, judi- 
cious, and consistent. So far as any rule of allotment has been fol- 
lowed, it seems to have been only to assign the largest grants to the 
most determinate, and at the same time expensive investigations; but 
the Association has not deemed it expedient to restrict itself to these. 
Whenever the committee of any section has been desirous of confiding 
any inquiry involving an outlay of money to a competent person, the 
committees of revision and approval have always been anxious to 
comply with the recommendation. The meeting will observe with satis- 
faction that the first step towards the solution of the geological question 
alluded to by Mr. Lubbock, has been taken under the superintendence 
of the committee appointed for the purpose. Mr. Whewell, to whose 
‘more special superintendence the conduct of this work was intrusted, 


XXXViil FIGHTH REPORT—1838. 


reports that a line has been leveled by Mr. Bunt from Bridgewater to 
Axmouth, to be thence continued to the Bristol Channel; and such 
marks have been left as will allow of repeating or extending the levels, 
and comparing at a future period the height of the several fixed points. 
We are thus led to say a few words about Geology, a science which 
is rapidly advancing to take its permanent station among the more ace. 
curate natural sciences. It is now six years since Mr. Conybeare laid _ 
before us his eloquent general view of its then existing state; but the 
lapse of a much shorter period in a science which is making such vi- 
gorous shoots, would present sufficient materials for a report which 
should enumerate and define the latest conquests it has achieved. The 
fact is, that the very literature of this subject is so vast, that none but 
the most practised and laborious geologists can keep pace with its pro- 
gress; and though the anniversary discourses of the successive Presidents 
of the Geological Society generally contain a sketch of the works and 
memoirs which have appeared in the course of the preceding year, still 
we are convinced, that a condensed retrospect of the progress of geo- 
logy, which should embrace a somewhat larger period and a wider 
range, executed from time to time at the request of the Association, 
would not only be grateful to geologists, but would also tend to com- 
bine the discoveries and promote the advancement of this science. But 
besides general reports on geology, this Association will, it is hoped, 
encourage a continued attention to the consideration of mineral veins, 
since there is no branch of geology of such direct public interest as 
the results of the miner’s discoveries. In a clear and instructive re- 
port formerly read by our Treasurer, Mr. John Taylor (himself a most 
experienced and able miner), he expressed a wish, which we trust to 
see accomplished, that miners would hereafter not rest satisfied with 
such observations and knowledge as the mere practice of their art re- 
quired, but would extend and combine their inquiries in such manner 
as to make them the foundation of more general and comprehensive 
views, and would tend to connect more intimately than heretofore the 
science of geology with practical mining. This subject, so important 
in its bearing upon the production of our mineral wealth, cannot be 
too strongly recommended to the attention of the Geological and Me- 
chanical Sections of the Association. We venture, indeed, to hope 
that the Newcastle meeting will be pre-eminently. marked by the dif- 
fusion of much sound mining knowledge, flowing as it must from the 
meeting together of the most experienced Cornish miners with those 
of Durham and Northumberland. We are further encouraged to in- 
dulge in this expectation from knowing that this meeting is honoured 
by the presence of an Austrian nobleman, long valued by English geo- 
logists, and whose thorough acquaintance with mineral veins, and all 
their complicated faults and changes, well entitle him to occupy the 


Se ee ee 
7 _ 


hp 


peal: 


ADDRESS BY MR. MURCHISON. XXXix 


high station confided to him by his sovereign*. And here we cannot 
but observe, that as, with all its mineral wealth, Great Britain is the 
only country in Europe without a national school of mines, so much 
the stronger is the call upon the British Association to promote the 
analysis of every natural phenomenon and useful invention connected 
with the art of mining. But while we make this appeal, we cannot 
assemble in this neighbourhood without congratulating the University 
of Durham on having led the way to the establishment of a school of 
mines and engineering, in which the principles and knowledge of this 
branch of science are regularly taught; and we further feel gratified, 
that so important a charge has been intrusted to men distinguished for 
their scientific attainments, including in their numbers one of the earliest 
promoters of the British Association, and one of its local secretaries at 
this meeting +. 

In the arrangements of the Association, the sciences of Mineralogy 
and Chemistry have been united. Such an union may be justified, not 
merely by its convenience in the distribution of our labours, but by 
the close alliance which subsists between those sciences, in all that 
concerns the connexion of chemical composition with crystalline forms, 
presenting so many remarkable relations of very recent discovery, and 
leading so rapidly, as Mr. Whewell has, on more than one occasion, 
so clearly shown, to enlarged views of the true principles of minera- 
logical qualification. But whilst we fully recognise the connecting 
links which unite those sciences, we trust that this partial and tempo- 
rary separation, which the active and somewhat absorbing study of 
palzontology has almost necessarily occasioned, will not be of long 
continuance, and that the laws of crystallization, which constitute its 
alliance with another science, will in the progress of our knowledge 
give as much importance to its connexion with the study of the ery- 
stalline structure of vast masses of the surface of the globe, as in the 
most searching analysis of its minutest particles. Let not, however, 
the exclusive advocates of any one theory of the proper relation of 
those sciences induce us to abandon inquiries so pregnant with re- 
markable conclusions, and which truly constitute the great basis and 
framework of modern geology: for the more minute and laborious our 
investigations, the more certainly do we make out that many rocks 
which were once supposed to be made up of inorganic matter, are in 
truth composed of animal remains. And do we not look for the 
presence among us of a distinguished philosopher of Berlin, who, 
above all others, has eliminated this discovery, and who, by the 
powers of the microscope, has revealed to us the skeletons of millions 


* Count Breunner, Director of the Imperial Mines, Foreign Member of the Geo- 
logical Society. 
+ Professor Johnston. 


xl EIGHTH REPORT—1838. 


of once living and perfect animalcules inclosed in a single cubie inch 
of solid stone. Well, indeed, may we quote the recent work of Lyell, 
who, rejoicing in this great discovery, exclaims with the poet,— 


The dust we tread upon was once alive.” 


In noticing the labours of the Section of Geology and Geography, we 
have to observe, with regret, that the latter science has not hitherto. 
received at our meetings that amount of attention to which it is justly 
entitled. When we consider the advances which the science has re- 
cently made under the auspices of the Royal Geographical Society of 
London, we cannot but lament that the British Association did not, at 
an earlier period, request a report from some one of its members upon 
the present state of our geographical knowledge, and upon those de- 
partments of it in which our researches might be most advantageously 
prosecuted. The annual reports of the Secretary of the Geographical 
Society,—particularly the last report of Capt. Washington, and the 
admirable discourse recently delivered by its President, Mr. W. R. 
Hamilton,—have in great measure supplied this deficiency, making the 
public acquainted both with much that has been done, and much that 
remains to be worked out in this very important branch of knowledge. 
But though we have thus been partially anticipated, we feel satisfied 
that such a report, by bringing into prominent notice, before the whole 
body of the Association, a statement of those great geographical pro- 
blems, whose solution is most specially desired or most easily effected, 
may serve to secure for the promotion of geography the application of 
some portion of those funds which have been hitherto exclusively 
appropriated to other sciences. 

The merits of the Statistical Section have been already made mani- 
fest, by the collection of a great variety of very important data. On 
this occasion we have to notice a very perspicuous and well-arranged 
report, which appears in our Transactions, upon the statistics of a 
large province of Hindostan, which sufficiently proves that a statist, 
who would really contribute to the advancement of statistical science 
by collecting facts in distant regions, must possess no slight qualifi- 
cations. In vain, in the absence of other essential branches of know- 
ledge, may he accumulate half-digested and ill-assorted observations ; 
he must also combine, as in the person of Colonel Sykes, the ac- 
quirements of the naturalist and geologist with those of an accom- 
plished soldier and of a man of general information. 

The accumulation of such facts is ebviously a very fit part of the 
labours of this Association, for they prove statistics to be truly a 
science of method. This science occupies the same relation to politi- 
cal economy in its most comprehensive sense, which astronomical ob- 
servations held relatively to astronomy before the discoveries of me- 


ADDRESS BY MR. MURCHISON. xli 


chanical philosophy enabled recent philosophers to make those early 
observations perform a mighty part in testifying the great primal 
truths of physical philosophy, and applying them to explain, and even 
to predict, the varied motions and phenomena of the earth and hea- 
vens. Such a stage there must be in every inductive science,—one in 
which immediate straining after comprehensive truths would be rash, 
while the marshalling and classing phenomena is a task full of use- 
fulness and hope. Those only who mistake the stage of discovery in 
which statistical observers are now placed,—who do not see that at 
present observation without premature speculation is the one and 
necessary step towards wide truths,—will either be impatient to weave 
rash theories from our present imperfect materials, or to scoff at the 
unscientific character of those who labour patiently to increase and 
arrange them. The analogy between the early stages of astronomy 
and the actual position of statistics might be made more complete. 
The secular character of many classes of statistical observations neces- 
sary to elucidate difficulties and disentangle truth might be easily de- 
monstrated, but enough has been said for the purpose of indicating the 
really scientific character of this useful branch of our Institution. 

It has fallen to our precursors to comment on the advances in Natu- 
ral History which have been made by the Section of Zoology and Bo- 
tany; and although, on this occasion, we are not presented with any 
report upon these sciences, you all know how ably they have been 
elucidated at former meetings, by a Lindley, a Jenyns, and a Richard- 
son; and also with what vigour that section has prosecuted its inqui- 
ries under the auspices of a Henslow and a Macleay. We must, how- 
ever, here allude to the distinguished Northumbrian naturalist who 
occupies one of our vice-chairs, and express our hopes that Mr. Pri- 
deaux Selby may soon be called upon to contribute what is yet a de- 
sideratum—a report upon the present state of the science of Orni-« 
thology. 

We have hardly ventured to allude to the separate proceedings of 
the Sections, for any discourse which should attempt to analyze their 
labours or to do justice to their usefulness would occupy too large a 
portion of your time. And besides this consideration, you, Gentlemen, 
are all aware, that these Sectional Meetings give rise to the Reports 
we have been considering, and also to the various practical researches 
which are carried out by the employment of your own funds, or by 
demands upon the country. If, therefore, the Reports constitute our 
high claim upon the literature of science, the proceedings of the Sec- 
tions must be viewed as the fresh current of scientific enterprise, which 
continually vivifies and renoyates the whole body of the Association. 

Among the investigations which are proceeding under the auspices 
of the Association, those which originated in the Committee of the 


xlii EIGHTH REPORT—1838. 


Medical Section, including several subjects of physiological interest 
reported upon in the present volume, are remarkahle for that spirit of 
co-operative labour which has not been common in this country, and 
which it is one of the happiest effects of these meetings to facilitate 
and encourage. In like manner, a question of great interest as re- 
gards one of the most important products of our mineral wealth and 
national industry, which had been discussed with more than common 
warmth and earnestness at former meetings of the Association, has 
been examined by an analysis, performed by one of the most distin- 
guished chemists of the present day, of the iron produced by the ap- 
plication of the hot and cold blast respectively ; which was undertaken 
at the request of the Chemical Committee, combined likewise with 
experiments, on an extensive scale, upon its relative strength and other 
properties, which were commenced at the desire of the Mechanical 
Section, by Messrs. Hodgkinson and Fairbairn, whose profound and 
extensive knowledge of practical mechanics so well qualified them for 
a task which they have executed with singular ability, enterprise, and 
skill. The experiments on Waves, which are detailed in Mr. Russell’s 
report in our present volume, were likewise undertaken at the request, 
and carried on by the aid of the funds of the Association. The accu- 
rate conception of a wave, its origin, propagation, and laws, is one of 
the most difficult and fundamental of those which are required in 
many of the delicate and embarassing inquiries of natural philosophy ; 
and the experiments of Mr. Russell are well calculated to illustrate 
and confirm many of the results which the mathematician has deduced 
from the theory of fluid motion. Adhering, therefore, to our design 
of mainly noticing those parts of our recent transactions which illus- 
trate the prominent points in our system of operations, we shall con- 
clude our remarks by noticing a report by Prof. Johnston, on a new 
and curious subject of chemical inquiry, as affording a good example 
of the execution of an object which the Association has had much in 
view. The discovery that there exist definite chemical substances, 
which are capable, under certain conditions, of assuming more than 
one crystalline form, not deducible from nor referable to each other, 
and accompanied with different physical properties ; and furthermore, 
that there are instances of substances which are capable (independently 
of any change of composition) of undergoing some internal transmu- 
tation sufficient to vary even their chemical affinities: these are dis- 
coveries which, pointing out a new road to the investigation of the 
hidden mysteries of molecular attractions, peculiarly deserve to be 
verified and extended. But it so happens that they have been little 
studied or prosecuted in our country; and, therefore, the Chemical 
Committee, in accordance with one of the prominent designs of the 
Association, selected this particular point as the subject of the Report 


ADDRESS BY MR. MURCHISON. xiii 


on Dimorphism, printed in this volume, which gives a fuller statement 
than we before possessed, of the facts arrived at by foreign experi- 
menters, the reasonings founded upon them, and the questions which 
are left for future inquirers to solve. This is the precise point at 
which the Association aims in the reports on the state of our know- 
ledge, which occupy the chief space in its publications; they are not 
intended, like the articles in an encyclopedia, to teach and diffuse 
science, but to advance it—to show what has been done, with a specific 
view to what there remains to do—to look forward to conquests to 
come, rather than backward on those which are past—to survey the 
border territory, and reconnoitre the debateable land. We have in 
this, as in other respects, followed in the steps of him who gave the 
original sketch of an Institution like the present. The great teacher 
of inductive science and experimental philosophy, who first showed 
the importance of knowing the lines which divide knowledge from 
ignorance, and in the memorable list of DEsIpERATA which he drew 
up, did more for “the progression of the sciences” than would have 
been done by any discoveries he could have made. 

Having thus endeavoured to elucidate, by reference to some portions 
of its recent transactions, the comprehensive system of this Association, 
and to mark the real value of its corporate influence, its pecuniary re- 
sources, and its concentrated intelligence, I would lastly notice that 
part of the system which has given occasion to our present muster in 
this prosperous and splendid city—the migratory character of our 
meetings. In these migrations there is a double advantage; the As- 
sociation gains much by them, and perhaps the places it visits do not 
gain less; for its visits may sometimes have the effect of drawing 
genius from obscurity, and giving an impulse to powers which might 
never have been exerted, and a direction to labours which might 
otherwise have been misapplied. To our own body two great advan- 
tages are derived: one is, that the wave, in rolling along, gathers to it 
all the scattered science of the land, and that a more general and 
powerful union is thus formed than could ever be collected by an 
Institution resting on a fixed point: the second is, that varied objects 
of interest and different opportunities of utility are offered by circum- 
stances proper to the different places which the Association visits; 
thus the lofty tower of York furnished means for the best experiments 
that have been made on the phenomena of rain; Liverpool contributed 
its contingent to our knowledge of the tides; whilst Bristol carried a 
line from sea to sea, to ascertain the permanence or the mutations of 
the level of the land and water. And does not this city and vicinity, 
Gentlemen, also present its own peculiar objects of speculation and 
opportunities of research? Is not the optical philosopher interested 
in its celebrated glass-works? Can the chemist contemplate with 


xliv EIGHTH REPORT—1838. 


indifference those conspicuous and truly magnificent establishments 
which exhibit, on so grand a scale, the application of those processes, 
which have been deduced and perfected in his laboratory, to pro- 
ductions so important in our manufactures and arts? Can the geo- 
logical or physical inquirer stand near its mines—those vast store- 
houses of nature for the uses of art, the theatre of the most beautiful 
of all the applications of science to the purposes of humanity—without 
having his curiosity awakened ? or contemplate those deep excavations, 
the most accessible of any that have been carried into the bowels of 
the earth, without being tempted to investigations which may lead 
perhaps to a better understanding of the internal condition and struc- 
ture of our globe? Or can we survey the architectural creations 
which surround us in the place in which we are assembled, where 
order and magnificence have replaced confusion and meanness, with a 
rapidity more resembling the illusions of an Arabian tale than the 
sober anticipations of experience, without being encouraged in our 
own efforts by witnessing such noble results of individual enterprise, 
genius, and arrangement, which have associated the triumphs of art 
with those of manufactures and commerce, and combined the refine- 
ments of wealth with the most varied productions of industry ? 


“ Hie portus alii effodiunt; hic alta theatris 
Fundamenta locant alii, immanesque columnas 
Rupibus excidunt, scenis decora alta futuris.” 


Finally, Gentlemen, there is another reason for these migrations, 
which it would be highly ungrateful in us to overlook, which is equally 
felt by the Association and by the place which it visits—the warmth of 
hospitality which we see these visits call forth, the union of hearts and 
the excitement of kind and friendly feeling acting on all our objects, 
like oil on the wheels of a vast and powerful machine, without which 
its every movement would be retarded, and its whole power brought 
toastand. Never, indeed, can the vitality of this Association be im- 
paired, so long as the leaders who have borne the bark of science along 
the waves shall lay stoutly to their oars. Assembling for a common 
cause, and confiding in each other, may they ever glory in having 
knit together all classes in the love of science; and whether presided 
over, as on this occasion, by a noble duke, alike illustrious for his just 
appreciation and generous encouragement of our pursuits, or in the 
ensuing year by some one eminent in their cultivation, we shall, we 
trust, go om waxing in strength, and holding out the cheering example 
of a great and triumphant commonwealth of science ! 


ree oe 


REPORTS 


ON 


THE STATE OF SCIENCE. 


Account of a Level Line, measured from the Bristol Channel 
to the English Channel, during the Year 1837-8, by Mr. 
Bont, under the Direction of a Committee of the British 
Association. Drawn up by the Rev. W. WuUFWELL, F.R.S. 
one of the Committee. 


1. AT several of the meetings of the British Association it 
was suggested, that the exact determination of the relative level 
of three points considerably distant from each other on the coasts 
of this island might throw light upon several important questions. 
Such a determination, it was represented, might especially be 
made subservient to the solution of the two important problems, 
-—how far the position of the earth’s surface is permanent—and 
what ought to be understood by “ the level of the sea.” For if, 
as some geologists think, many parts of the earth’s surface are 
slowly changing their position, such a change is extremely dif- 
ficult to prove or disprove by observations made at any one point. 
But if three points were at one time determined to be in one 
horizontal surface, and were at a subsequent period found to be 
at different heights, their relative elevations at the second epoch 
would not only establish the fact of a change in the position of 
the earth’s surface, but would enable us to determine, by an easy 
calculation, the angle through which this part of the surface had 
been elevated, and the axis about which the elevation had taken 
place. And with regard to the level of the sea, it is well known 
that surveyors and naval men are in the habit of assuming the 
surface of low water of spring tides to represent this level. 
Now not only is such a surface extremely indefinite (varying 
very considerably with the parallax and declination of the moon 
and sun) but it is not in fact, not even approximately, a level 
surface at all. The level of the sea, thus determined, would be 

VOL. vil. 1838. B 


24 EIGHTH REPORT— 1838. 


twenty feet lower on some parts of the coast of England than 
on others. And although men of science have very generally 
seen the propriety of taking mean water, (the mean of low and 
high water,) for the level of the sea, this selection, till confirmed 
by some actual observations of facts, might appear arbitrary and 
insecure. But if it be found that the mean water is at the same 


level at different and distant points of the coast, where the low’ 


water is at different levels, the propriety of taking mean water 
for the level of the sea will probably be generally acknow- 
ledged. 

It may be observed, moreover, that the question of the per- 
manence or change of the height of any point of the coast (un- 
connected with a system of interior leveling) cannot be de- 
cided by observation, except by reference to the level of the sea ; 
and therefore to determine what is the level of the sea is im- 
portant also to the geologist. On coasts where there are tides, 
the question of the stability of the land involves the question of 
the laws of change of the water. 

2. For these reasons it was considered desirable to ascertain 
by careful and exact levelling the relative heights of certain 
points of the coast of England, and to refer these points to the 
sea by adequate tide observations. The British Association at 
its meeting in 1834, voted a sum of money (500/.) to be em- 
ployed upon this object, and appointed a Committee to decide 
upon and direct the requisite operations. The same thing was 
done at the subsequent meeting in 1835. But the difficulty of 
fixing upon a plan of operations and of selecting the means of 
carrying it into effect by a joint deliberation of 2 large Com- 
mittee scattered over the whole empire, prevented any active steps 
being taken towards the attainment of the object. At the meet- 
ing at Bristol in 1836, in order to remedy this inconvenience, 
those members of the Committee who had the opportunity of 
conferring with each other after the separation of the Association 
took upon themselves the task of directing the execution of the 
plan. And it appeared to them desirable that a person should 
be selected to perform the leveling operation for the Associa- 
tion, independently of any other surveys which might be going 
on; for no materials collected for the purpose of any other sur- 
vey could, in accuracy and other conditions, answer the purposes 
contemplated by the Committee. They considered themselves 
fortunate in being able to engage Mr. Bunt of Bristol in this ser- 
vice, having entirely satisfied themselves of his accuracy and 
scrupulousness in observing, and of his clear apprehension of 
the nature of the operation. They also took the precaution of 
directing Mr. Bunt to execute a preparatory level from Bristol 


a) 


REPORT ON A LEVEL LINE. 3 


to Portishead, (a distance of eleven miles) and back to Bristol, 
in order to ascertain the degree of accuracy which could be at- 
tained in this operation. The total amount of error resulting 
from this operation was 1°07 inches ; but there appeared grounds 
for believing that the uncertainty of the result was very much 
smaller than this quantity ; and this belief has been confirmed 
by the general course of the subsequent operations. 

3. An excellent telescope level was constructed by Mr. Simms 
for the Association, to be used on this service, and also a level- 
ing staff, for which however Mr. Bunt afterwards found it con- 
venient to substitute one of his own construction. This is de- 
scribed in the Appendix to this account. 

4. The extremities of the line selected were on the north coast 
of Somerset and the south coast of Devon, as affording the case 
where coasts belonging to separate seas could most easily be 
brought into connexion. A north and south line being thus 
obtained, it was proposed to extend the operation to the east- 
ward, so as to obtain a third point under suitable conditions. 

The first line selected for leveling*, on a careful inspection of 
the country, was one proceeding from Bridgewater up the river 
Parret by Langport to Ilminster, Chard, Axminster, and thence 
to the mouth of the river Axe, which was fixed upon as one of the 
terminal points where tide observations were to be made. Bridge- 
water was connected with the sea at the other extremity by a 
line, which, skirting the Quantocks, reached the shore in the 
first instance at Stolford opposite the Wick rocks ; but was after- 
wards carried further to the west in order to reach a more solid 
rock, and terminated at Kast Quantocks head near Watchett. 

5. The leveling from Bridgewater to Axmouth was begun 
May 16, and ended July 8, 1837. From Bridgewater to Wick 
rocks the operations of leveling and preparing for tide observa- 
tions were carried on in October 1837. Tide observations were 
made at Axmouth from January 4, to February 2, 1838, and at 
Wick rocks from November 9, to December 9, 1837 ; and again 
at Axmouth, simultaneously with Portishead, July 14 to 21, 
1838. 

The line thus leveled crossed no very great elevations, and 
was for the most part very conveniently even. The highest 
point was at White’s House near Chard, where it attained a 
height of 280 feet. 

6. The extension of the leveling process to any considerable 
distance east or west of this line was a matter of difficulty ; the 
ground in both directions consisting of a series of hills and val- 


* See Plate I., (the map). 
9 


4 EIGHTH REPORT—1838, 


jeys of considerable magnitude. Such a country would require 
to be leveled by a series of very short distances; and this cir- 
cumstance would not only add greatly to the labour and expense 
of the operation, but would render doubtful, in a very material 
degree, the accuracy of the result. It was therefore judged ad- 
visable to be content with extending the level rorth-eastward 
to Portishead and Bristol. By this means the east and west- 
extent of the surface surveyed became nearly equal to the ori- 
ginal north and south line ; and the level line which rests upon 
the Quantocks at one extremity, crosses the Mendips and the 
Leigh Down Hills, connecting a great number of different geo- 
logical formations. 

7. This line from Bridgewater to Portishead was leveled 
between May 15, and July 6, 1838 ; and tide observations were 
made at the latter place in May 1837, and July 1838. 

8. Both in the leveling and in the tide observations, every 
precaution was taken to avoid mistakes and to ensure accuracy. 
As leveling operations of a very delicate kind have rarely been 
performed, and are nowhere sufficiently described, it is con- 
sidered worth while to reeord the method employed in this in- 
stance, and an Appendix is added containing this description. 
It may here be observed, that the most important precaution, 
that of making the distances of the staff from the telescope 
equal in the fore observation and the back observation, was 
throughout attended to; and that all the lines were leveled in 
both directions, proceeding from the beginning to the end of the 
line, and then returning back from the end to the beginning. 

9. By employing this method of verification, an apparent 
error in the process is brought into view, for which it is difficult 
to account, but which is so constant in its occurrence that we 
cannot help supposing it to depend on some general cause. The 
error consists in this ;—that in proceeding with the leveling 
operation along a line which is really level, the further end con- 
stantly appears, from the observation, to be the lower end; and 
the amount of this depression appears to increase with the di- 
stance. Hence, when we go to the end of a line and then return 
to the starting point, we find the resulting elevation of the point 
lower than its real elevation. The difference arising from this 
cause is never considerable, but is always in the same direction, 
and generally (in the same series of operations) greater in pro- 
portion as the distance is greater. Thus in the line from Bristol 
to Portishead (11 miles) it was 1:07 inches; from Bridgewater 
to Axmouth (40 miles) it was 4°11 inches; from Bridgewater to 
East Quantockshead (16 miles) it was L 94 inches ; from Bridge- 
water to Portishead (29 miles) it was 7°6 inches. 


eo Ae 


- REPORT ON A LEVEL LINE. 5 


10. It is very difficult to explain the cause from which this 
seeming error arises, or even to conceive any cause from which 
it can arise. The errors arising from the curvature of the earth, 
and from any permanent refraction, are eliminated by the con- 
dition of equal distances in the fore and back observations. The 
difference does not seem to arise from the effect of the sun’s rays 
on the instrument, for it is not removed by shading theinstrument 
with white paper ; nor from any rise of the peg between the fore 
and back observation, for it is not confined to soft ground. It 
appears to go on increasing with the time during which the ob- 
servations are continued, and is such an error as would result, 
if we suppose that in every interval of time between the back and 
the fore observation, something takes place by which the staff 
is apparently (by refraction or otherwise) less elevated (or more 
depressed) at the fore observation than it had been at the pre- 
ceding back observation. For these elevations are supposed to 
be equal in the process ; and if the elevation of the fore point by 
refraction or any other cause be the smaller, the point will ap- 
pear to be lower when it is really on the same level. This state- 
ment, however, is made rather with a view of explaining the 
nature of this error than of assigning its cause. 

11. But since it is thus probable that this apparent error arises 
from some constant and general cause, it is clear that we shall 
get rid of its effects in each case by taking the mean of the first 
and last results. We may therefore suppose the mean difference 
of levels obtained by leveling between two points, first in one 
direction and then in the other, to be accurate within limits very 
much smaller than the errors above mentioned. We may venture 
to confide in this result to a fraction of an inch. 

12. The relative heights of the parts of the lines surveyed 
being determined by the operations of which we have been speak- 
ing, marks were fixed at various points, by means of which the 
position of the line now measured may hereafter be again dis- 
covered. These marks are the following. A place was selected 
in the solid rock on the shore just below the fort at Portishead ; 
and in this was inserted horizontally a cylinder of iron, two 
inches diameter and fifteen inches long, containing in its centre 
a brass wire one eighth of an inch in diameter, which marks 
the position of the standard point, about eight feet above the 
highest high water. This mark is on the property of James 
Adam Gordon, Esq., of Naish House, who kindly gave per- 
mission for its being placed there. The mark at East Quan- 
tockshead is on a farm called Perry Farm, the property of J. 
F. Luttrell, Esq., of Dunster Castle. It consists in a block 
of granite, a ton and half weight (the gift of the corporation of 


6 EIGHTH REPORT—1838. 


Bridgewater) in which is inserted horizontally, without lead, a 
copper cylinder an inch and a half diameter and fourteen inches 
long. In order to prevent this bolt being drawn, it is fastened 
with a copper key passing through a transverse hole into a 
notch in the bolt, and the transverse hole is filled with lead. A 
similar block of granite, (also presented by the corporation of 
Bridgewater) with a similar copper bolt, is the mark at Wick 
rocks, in the parish of Stogursey near Bridgewater, which stands | 
on the property of Sir Peregrine P. Acland, Bart. The mark 
at Axmouth is a similar block of granite, procured by J. H. 
Hallett, Esq., of that place, on whose property the mark 
stands, and who has manifested a great disposition to forward 
the operations in every way. The kindness and liberality of the 
gentlemen who have been mentioned, on whose ground the marks 
have been inserted, have much forwarded the undertaking, and 
deserve the best acknowledgement the British Association can 
make. These gentlemen are also willing to perpetuate the obli- 
gation which science thus owes them, by allowing themselves to 
be considered the guardians of the permanent level marks thus 
existing on their property; and this is a kindness the more 
valuable, since the British Association neither has nor can have 
any valid right to such services. The marks of which this 
statement contains the record, may hereafter be of great conse- 
quence in settling important questions of a scientific nature, if 
their preservation be, as we do not doubt it will be, kept in mind 
by the proprietors of the estates above mentioned. 

There is also a bolt inserted in the wall of the church at Ax- 
mouth ; and it is intended to place a similar mark in the church at 
Uphill, a village situated where the level line crosses the western 
extremity of the Mendips. 

With the permanent level points at Axmouth, Wick rocks, 
and Portishead, the surface of thesea was compared by means of 
tide observations made at first for a month at each of those places. 
In pursuance of the views already stated, the mean of high and 
low water was taken as representing the level of the sea. In 
fact, this level of “‘ mean water’’ is so nearly constant, that even 
a few days will give its position with tolerable accuracy ; and 
observations continued for a fortnight, which of course includes 
spring tides and neap tides, give the result with great precision. 
The first result was, that while the level of mean water at Ax- 
mouth and at Wick rocks did not differ by more than a small 
fraction of an inch, the level of mean water at Portishead was 
four inches and a half lower than at the other places. As how- 
ever it appeared possible that this difference might result from 
the observations heing made at different times of the year, further 


REPORT ON A LEVEL LINE. 7 


observations were made simultaneously at Axmouth and at Por- 
tishead, from July 16 to 30, 1838 ; the result of which was that 
the level at Portishead is nine inches higher than that at Axmouth. 

13. The difference between the result of the first and second set 
of tide observations at Axmouth (1°29 feet in the mean level,) 
was such as to require examination. It appeared possible that 
this difference might arise from some of the inequalities which 
affect the tide, and depend upon the time of year; one set of 
observations having been made in January 1838, and the other 
setinJuly. I therefore requested Mr. Bunt to examine the Ply- 
mouth observations of high and low water for the same period 
(with which observations I was supplied by the Admiralty). The 
result of this examination was that the mean sea levelat Plymouth 
was only one fiftieth of a foot higher in January than in July 
last : and it therefore appears certain that no annual inequality 
of the tides is the cause of the difference. I am led to ascribe 
it to the circumstance, that in the observations of January, the 

low water at Axmouth was taken within the bar at the mouth of 
' theriver. In July, the low water, within this bar, was certainly 
higher by a foot or two than it was on the outside ; and though the 
bar had altered its position in the intermediate time, I have little 
doubt that it was in such a condition in January as to vitiate 
the observations of low water. The observations of low water 
made in July last, simultaneously with those at Portishead, were 
made entirely outside the bar. 

14. Taking the simultaneous observations made at Axmouth 
and Portishead in July, 1838, as the most free fromobvious objec- 
tions, we obtain the following results respecting the comparative 
level of the sea at the two extremities of our line. The measures 
of level were all referred to a certain zero point, assumed 100 
feet below the point where the operations began. The level of 
the mean tide above this zero was 

at Axmouth . . . 71:96 
at Portishead. . . 72°69 


difference . . *73 foot; 
or something less than nine inches. But the range of spring tides 
at Axmouth was 5 feet above and below this level; at Portis- 
head 17°87 feet above and below. Hence we have for the relative 
levels of high and low water at spring tides 
High Water. Low Water. 
attAmmouthn ses ce oF 9G | oc os). pe,- 86°96 
at Portishead. . 90°56 . . . 54°82 


differences . . 13°60 . . ..: 12°14 


8 EIGHTH REPORT—1838. 


Thus the sea at Portishead is at high water 13°6 feet higher and 
at low water 12°14 feet lower than at Axmouth. ~- And if we take 
the extreme tides which occurred during the observations, the 
differences are still greater; for the greatest range of tides at 
Axmouth was 10°8 feet, and at Portishead 411 feet. And the 
difference of the halves of this is 15:1 feet, which is greater by. 
2:23 feet than the difference of the ranges just employed. Also 
these elevations of the ocean are nearly contemporaneous ; for 
the high water at Axmouth occurs (at a mean) forty-four minutes 
earlier than at Bristol, and at Portishead two minutes and three 
quarters later than at Bristol. 

We have in these results a very strong indication that the 
mean tide is what we must take as the level of the sea, for it 
would be difficult to believe that the level of the sea is fourteen 
feet higher at Portishead than at Axmouth, or sixteen feet lower, 
which are the consequences of taking for the level high water 
or low water at spring tides*. 

We may add, that at another of our stations, the Wick rocks, 
by a month’s observations in November, 1837, the mean level 
was 73°11, or 3°8 inches higher than at Portishead. Perhaps a 
portion of this difference may be due to the inevitable errors of 
the operations. The range of the tides at this place is nearly 
the same as at Portishead, and the time of high water (at the 
mean) about thirty-seven minutes earlier than Bristol, and there- 
fore about seven minutes later than Axmouth. 

15. The general result to which we areled is that the mean tide 
must be taken as the level of the sea. This result had already 
been arrived at by various persons. Capt. Denham had asserted 
it as the consequence of his observations at Liverpool ; and Mr. 
Walker had been led to the same conclusion by the tides of Ply- 
mouth. I had also pointed it out as the result of the Plymouth 
observations in the Philosophical Transactions for 1837. 

16. But these conclusions were supported only by observations 
made at asingle place; namely, by its appearing that the height 
of mean tide was nearly constant, (varying at most only a few 
inches) while both high and low water varied by many feet. 
And so far as I have yet seen the evidence, it seems probable that 
though the change of the level of mean tide during a fortnight 
be small, there really is some regular change of this level tide, 
produced by the effects of the moon and sun. But the small- 
ness of the changes of this level, as it is now announced, rests 
upon quite different evidence, and appears to indicate a perma- 


* In Plate II. I have represented the relative range of the tides at these 
places as observed. 


oe ee ee ee 


ie ti 
Noe 
i 


REPORT ON A LEVEL LINE. 9 


nencé of a more rigorous nature. The mean level of mean water 
at one point of the coast of the island, taken for a semilunation 
(and probably still more if taken for several lunations), may be 
asserted to agree with the mean level at another point taken 
in the same manner, within a very few inches. Perhaps the 
agreement, if places situate on the open sea were taken, is still 
nearer; for Portishead, and even Wick rocks, may be affected 
by the narrowness of the Bristol Channel, which may elevate 
the low water there, as it certainly does inariver. Jt appears 
very probable that the level of mean tide at different places on 


the open coast agrees as nearly as the operation of leveling can 


determine. 

17. This result is not only very curious in itself, but pregnant 
with important practical consequences. It is very clear, from the 
slightest consideration of our results, that nothing but error and 
confusion can result from processes, such as have often been em- 
ployed up to the present time, in which heights are determined 
from ‘‘ the level of the sea,’’ this level being understood to be 
that of low water spring tides. Such heights are not measured 
from a Jevel at all, but from a surface of which some parts are 
sixteen feet lower than others within the limits of our operations, 
and probably above twenty feet, if we take the extreme cases on 
the shores of our island. The only method of stating heights 
which can have any pretensions to accuracy, is that of reckoning 
them from a conventional fixed datum upon the solid land; to 
which datum the sea as well as the land must be referred by 
proper leveling operations. 

18. As a specimen of the doubt and confusion which have 
hitherto prevailed on this subject, I may quote a passage from 
Mr. Telford’s report on the project of a ship canal, intended 
to connect the Bristol Channel with the English Channel, and 
following nearly the same course as our level line. He says 
“the total distance from Beer Harbour [near Axmouth] to 
Bridgewater Bay [in which are Wick rocks] is forty-four miles 
fivefurlongs. The fall from the summit to high water at an or- 
dinary tide in Bridgewater Bay is 231 feet; but by taking an- 
other tide at Beer, the fall was found to be 233 feet.’’ 

The vague mode in which this result is expressed, an ‘‘ordinary 
tide ’’ being taken in Bridgewater Bay, and “ another tide ”’ at 
Beer, without any indication whether any correction was re- 
quired for the difference of tides, and whether the result could 
pretend to any accuracy, is, I conceive, an instance of the impos- 
sibility of referring any elevations to the seain a satisfactory man- 
ner, till it is determined how we are to allow, not only for the 
difference of high ana low water, but for the different heights of 


10 EIGHTH REPORT—1838. 


different high waters; that is, till a proper discussion of tide 
observations is combined with a system of leveling operations. 

I may add that this result is certainly erroneous ; for it gives 
the high water in Bridgewater Bay only two feet higher than on 
the south coast of Devon ; whereas by our observations, which 
certainly cannot err a foot, the former level is at least fourteen feet 
higher than the latter. The difference, which is perhaps not to 
be wondered at in rough leveling such as that performed in a 
preparatory survey for a canal, is twentyfold greater than our 
operations, carried backwards and forwards, and only differing 
one or two inches in the result, allow us to consider as possible. 

19. We may observe, in conclusion, that the result of our 
operations, namely, that the mean tide in different points of the 
coast is at the same level within a few inches, is of no small 
practical value. For this being so, the level of any place within 
a moderate distance of the coast may be determined, for the 
purposes of canals or railroads, or any similar undertakings, 
with reference to the level of places hundreds of miles distant, 
by taking a fortnight’s observations of high and low water, and 
then leveling a few miles into the interior of the country. 

20. It may perhaps be said that the conclusions thus stated de- 
pend upon a single comparison; that of the south shore of the 
Bristol Channel, with the north shore of the English Channel. 
When itis recollectedthat there are, omitting thesmaller fiexures, 
some hundreds of miles of coast between the two extremities of 
our line, and that the tides at the extremities differ as forty feet 
and twelve feet, I think it is impossible not to allow great value 
to the result; the operations being, as I conceive, of unim- 
peachable accuracy. But I am at the same time quite ready to 
admit that it would be highly desirable to have the result corro- 
borated by other comparisons of the same kind, especially by a 
comparison of the east and west shores of England. For this 
purpose it might be desirable to carry a level line from Bristol, 
which is already connected with our operations, to London. The 
expense of this, if performed in the same manner as that which I 
have described, would be great; but it appears to be worth con- 
sideration, whether this expense might not be much reduced by 
observing the waters of existing canals. 

21. I will add, that such an extension of our level to London, 
and in like manner to Plymouth, Liverpool, and other principal 
ports of the empire, would be desirable in another view. As I 
have already said, we cannot speak with accuracy of any level 
except a conventional one; and as each of these ports has its 
own tide scales to which the rise and fall of the sea’s surface is 
referred, it would be desirable to compare the absolute position 


REPORT ON A LEVEL LINE. Il 


of these scales with regard to a level surface. We may in this 
manner, and in no other, learn the true form of the ocean at any 
time ; besides the practical advantages, which, as I have said, 
would flow from having standard levels in various parts of the 
island. I may mention, that the kingdom of the Netherlands 
already possesses such a system of levels, by which all points of 
its surface are referred to a certain zero at Amsterdam. 

Whether such an extension of the level line measured for the 
Association be desirable, may best be determined by the Com- 
_ mittee of the Physical Section. In the mean time I trust that what 
has already been done possesses no small value, being, so far as I 
am aware, the first attempt of the kind, executed with great care, 
and I see every reason to think, with great accuracy. 


22. The following are the heights of the marks above the zero 

point. 
Feet. 

Iron bar at Portishead Fort. . . wives Pa TS 
Temporary mark at Wick rocks (Station Ne 810). . 99°4833 
Copper bar in granite block, Axmouth . . . . . 83°6513 
Copper bar in Axmouth church. . . Hie serps) OR BSL 
Copper bar in Uphill church. (This is not yet insert- 

ed. The + cut on the east end of the church is at 

gheticight). (6. -. oo. se 2OS8805 
Copper bar at Perry Farm, East Quantockshead . - 244°4365 
Copper bar at OE SI TR SK a Be ES 
Level of mean water at Portishead. . . . . . . 72°69 
WV tele rocks), jeri: b'-Gaa! eels’ Lh 
PEMIAOWUNS 2. orateisy. $c (Bi geese 


Account of the Leveling Operations between the Bristol 
Channel und the English Channel, hy Toomas G. Bunr. 


PREviousLy to my commencing the leveling which I had re- 
ceived instructions from Professor Whewell to undertake on 
account of the British Association, I was desirous of deriving 
such assistance as might be obtained from any published account 
of a similar enterprise, in which due attention had been paid to 
the niceties which the operation requires, and the best means 
for ensuring accuracy ascertained and pointed out. All the or- 
dinary treatises on leveling are of the most elementary and su- 
perficial kind ; and the only account I have met with which could 
at all assist me is that given by Captain Lloyd in the Philoso- 
phical Transactions for 1831, which details with clearness, and 


12 FIGHTH REPORT—1838. 


at considerable length, every particular connected with his level- 
ing from Sheerness to London ; a scientific enterprise of similar 
character to that in which I was about to engage. ‘This memoir 
of Captain Lloyd I regard as one of considerable value, and 
have derived from it much information and assistance. Most 
of his arrangements appear to me to be very judicious, and se- 
veral of them I have either adopted or imitated. On one im- 
portant point, however, I am obliged to differ from him, to 
which I shall have occasion to advert presently. 

The instruments made for this undertaking were a spirit-level, 
and brass leveling-staff, by Simms, London. The telescope, 
though only 14 inches in length, was found to bear the high 
magnifying power of 26 so well under all circumstances, that 
the other eye-piece with which it is furnished was never em- 
ployed. The glass spirit-tube is so nicely ground, that the 
position‘of the air-bubble is sensibly altered by raising or lower- 
ing either end of the tube jmaoth part of an inch. In the focus 
of the telescope are a horizontal and two vertical hairs, which 
latter afford a very convenient means of measuring the distance 
of a station, within about the ;},th part of the truth, by count- 
ing the number of intercepted divisions of a scale made for the 
purpose, and held horizontally over the station by an assistant. 

The legs which were made to support the level, although very 
strong, were found to vibrate so much from the action of the 
wind, as to render it difficult to take a correct observation, ex- 
cept in perfectly calm weather. It was also next to impossible 
to level the spirit-tube, unless by accident, for want of a slower 
and more delicate motion than that afforded by the parallel 
plate screws. I therefore ordered a very strong stool to be made 
by a carpenter, the top of which was a thick board 12 inches 
in diameter. The level was then detached from its former sup- 
port, and fastened to a circular piece of mahogany, which rested 
by three foot-screws on the top of the stool, and was firmly se- 
cured to it by a stout wooden screw, with a nut at bottom, 
passing through both the circular boards. On trying this appa- 
ratus, | found that a more delicate vertical motion was still 
wanted, which was at length perfectly attained by causing one 
of the three foot-screws to rest on a small brass lever at a very 
short distance from the fulcrum, while the farther end, furnished 
witha fine screw and milled head, communicated about ;;th of its 
own vertical motion to the foot-screw of the level, affording a 
very simple and delicate means of adjustment. 

The level, although now incomparably steadier than before, 
was still found liable to disturbance from the wind, when it blew 
with any considerable force ; to protect it from which we car- 


= k 
, 
4 


REPORT ON A LEVEL LINE. 13 


ried with us a piece of canvas, 6 feet square, nailed to two poles, 
which were sharpened at the bottom, to enter the ground. This 
screen being held firmly by two men on the windward side of 
the instrument, sheltered it so completely, that I was able to 
proceed in windy weather, with but little interruption. 

The brass leveling staff was employed in leveling between 
Bristol and Portishead ; but being found inconvenient, and liable 
to get out of repair, was obliged to be laid aside. The staff 
which I subsequently constructed and used, is of wood, 9 feet 
long, and 2 inches wide, a single piece of straight- grained oak. 
On the face are two different scales of equal parts. One is the 
common scale of feet and hundredths of a foot; the other has 
larger divisions, in the proportion of 19 to 16 nearly, or more 
exactly, as 1:18702 to 1: an aliquot ratio of the scales having 
been purposely avoided. Both of these are reckoned upwards 
from a common zero at the bottom of the staff. The centesimal 
divisions of the foot are produced in strong black lines towards 
the left, and large figures denoting feet and tenths placed against 
them, so that the height may be read off at the telescope to the 
tooth part of a foot at a distance of 150 or 200 yards. These 
marks are also useful for directing the assistant where to fix the 
vane, by calling the division to him, especially when the reading 
was near the top of the staff. A stud of wire, about half an 
inch long, projects from the bottom of the staff, and a hole is 
bored to receive it in the top of the peg which is driven into the 
ground at every station, and on which the staff rests during the 
observation. A small spirit-cup with a glass cover, screwed to 
the lower part of the staff, serves to adjust it to a vertical posi- 
tion, in which it is held fast by a clamp attached to three strong 
legs, jointed and folding together, in the usual manner. 

The vane is a small mahogany box, about 3 inches in each 
dimension, open at the ends to admit the staff, which slides 
through it. ‘Two large wooden screws at the back of the vane 
clamp it very firmly to the staff, and preclude all danger of 
shifting. In front is a frame of brass, about 2 inches square, 


sliding within an outer frame of brass screwed to the vane, with 


a range of motion of about half an inch, either upwards or down- 
wards, being moved by a large vertical screw with a milled head 
working through the lower part of the outer frame. A square 
aperture, corresponding with the inside of this frame, is cut 
through the mahogany, in order that the divisions of the staff 
may be seen. A small ivory door moving on a hinge, is fitted 
into the sliding frame, on which are drawn two thick black lines, 
crossing each other at a small angle, and a black ring with a 
white circular spot within, at the centre, or intersection. At- 


14 EIGHTH REPORT—1838. 


tached to the inside of the sliding frame, and exactly behind the 
centre of the white circle, is a vernier, nearly in contact with 
the face of the staff, which divides the hundredth of a foot into 
five parts, of 20 ten-thousandths each, so that the observation is 
read off and recorded to four decimal places. The white circular 
spot, and the angular spaces between the lines, may be bisected. by 
the horizontal wire of the telescope, with great exactness. In 
favourable weather, I have usually found the average error, or 
the difference of a single reading from tne mean of the number 
taken to be about 315th of an inch, on a distance of 88 yards, 
or about a quarter of a second of angle. (See Wood-cut at the 
end of this paper.) 

When the vane was raised so near the top of the staff as to be 
out of the reach of the hand, the adjusting screw was worked by 
a long fork of stout wire thrust into holes made in the milled 
head to receive it. A groove made in the upper part of the 
staff receives the fork when it is not in use. 

In leveling, I proceeded regularly in the following manner. 
Two equal distances, usually of 4 chains or 88 yards each, ha- 
ving been measured forwards from the last station, the level was 
placed at the end of the first distance, and, at the second, a 
strong wooden peg driven firmly into the ground, for the fore 
station, the level being exactly midway between the stations. 
When, (as happened in a very few instances,) I was prevented 
from making the fore and back distances equal, compensating 
unequal distances were immediately afterwards taken, so that 
the sums of the two sets of distances were kept equal through- 
out. The staff being held vertically on the back station peg, by 
the means before described, and the first observation taken, the 
height was read off and written down by the assistant in a rough 
minute-book which he carried for the purpose. ‘The vane was 
then purposely thrown out, by turning back the screw, the level 
re-adjusted, and a second reading taken. If these readings 
agreed within 20 10.000ths (about z}th of an inch), the staff 
was brought forward to me, when I read off and inserted the 
last reading, according to both scales, in separate columns of my 
book; the mean of both readings was also inserted in a third 
column, after my assistant and myself had cailed over and com- 
pared the last reading. The assistant then read off and called 
to me the last reading from the large scale, as a check on what 
I had entered in my book. The needle bearing and distance in 
links, being aiso inserted in their respective columns, completed 
the back observation. The process in taking the fore observation 
was the same, except that instead of having the staff brought to 
me to be read, I had then to carry forward my level to the staff. 


REPORT ON A LEVEL LINE. 15 


A rigid adherence to this system rendered it improbable that 
a wrong reading could be written down, without immediate de- 


tection :—in fact, such an instance does not appear to have uc- 


curred. Had it even been so, a discrepancy must have existed 
between the columns of different scales, which would have been 
readily detected on casting up and comparing the totals, at the 
end of the day. From erroneous readings, therefore, it is evi- 
dent, there was little or nothing to fear ; but these are far from 
being the only, or the principal sources of error. On one or 
two occasions, we were very near committing a mistake, in be- 
ginning at a different station from the one on which we had 
previously closed. This would have occasioned an error, per- 
haps of large amount, which could only have been detected by 
the second and independent series of levels, taken over the 
ground in an opposite direction. For this reason alone, I should 
not consider it safe to depend on one course of levels only, 
whatever may have been the precautions used to guard against 
error. 

The total length of my line of leveling between Portishead 
and Axmouth, besides the branch lines to Bristol and East 
Quantockshead, is about 74 miles. This distance was divided 
into separate stages; each of which, averaging about 10 miles 
in length, was twice leveled over, first in one direction, and 
then in the opposite, before the next stage was commenced. It 
is very remarkable, that with afew partial exceptions, the heights 
of all the points touched upon by both series, came out less by 
the levels returning, than by the levels going: so that the first 
station, or starting-point, always appearedlower when I returned, 
than it was at my setting out. But as the height of this point 
is the same in both cases, the error must, of course, be thrown 
on the distant point, or station at which the returning levels 
commenced, which reverses the first apparent differences, and 
makes all the heights in the second series progressively greater 
than those in the first, the most distant point having the greatest 
error. The following table gives the differences thus found at 
20 points along the line between Portishead and Axmouth, the 
height, in every instance, coming cut greater from the series of 
levels returning towards Portishead. 


No. of Station Miles from Height greater by 
in Minute-book. Portishead. 2nd big Bhs Levels. 
MBBS aly doe tk ee cnet sin ihiy o)  CRODD 
LOR ots twane eee is lieaiien is, epee 
GOS rete s: hg MeO a eh ayers os OE 
PB oy ate ees ible a Tres Ye ile Bey AS 


16 EIGHTH REPORT—1838. 
No. of Station Miles from Height greater by 
in Minute book. Portishead. 2nd than Ist Leyels. 
: Feet. 


Lae Bedale ate ilo) 3G eee 
O78) asst stata as LBV: 4%: 3 /¢-00) a RON 
D220 0) sri selauet WEB Ys 4nh sor 6 ORE 
REG sdeiitace teh) LB oo eis yey Oe 
DiOea Capel em BF SH ecu Oe 
TO OBH Ee Bi SG l “BOM seo. ver ice eee ae 
Dare ee OSs Kayak bey as 

SBMA Masih a By ite] 5 ey) costal) ORG 
alee eh eins ADs sts tee de OP 
Wired 65 48 aa, he ey OF GES 
MCCHAP Basie} Sele JAD iol! Tel pr «GOS 
DUO Maite aes He Bits ¥y2 Msn) ih ONBGES 
DAG ie athe) oar? pad OO wy sizeny dH) ef} OPIOEE 
BABY alee DOLE S ae. elreae Ls 
AQ Cs ABR ahi IGE Waele beast GRO age 
AG Di Rae evans he Bag NOEs ak) coy sina ah RARE 
G5Gr > sis ahh ret & dh ts. eee 


After the most careful examination of every circumstance 
which could possibly tend to occasion these curious differences, 


I am inclined to believe that they arise principally from rapid ~ 


variations in the amount of atmospheric refraction which occur 
during the time that elapses in a single observation, and that 
the progression of the error is in some way or other connected 
with the progressive changes of the average temperature during 
the course of the day, from about eight in the morning till six 
or seven in the evening,—the usual limits of my working hours. 
These variations in the refraction are much greater and more 
sudden in summer than in winter, especially during the forenoon 
of a hot and sultry day, when there are frequent alternations of 
cloud and sunshine, and copious exhalations of moisture from 
the ground. On such occasions I have sometimes known the 
sudden clearing away of a cloud from the sun followed almost 
in an instant, by a change in the apparent height of the vane 
amounting to ;1,th of an inch, or more, on a distance of only 88 
yards, At other times the change has been more gradual, so 
that several successive readings, taken at intervals of two or 
three minutes, have all either increased or diminished progress-~ 
ively. Different seasons or states of the weather may therefore 
fully account for the more rapid increase of these differences at 
certain times than at others, such as the above table presents, in 
which the errors are found proportionably greater between Portis- 
head and Bridgewater, than between Bridgewater and Axmouth; 


=r 
¥ 


REPORT ON A LEVEL LINE. 17 


the latter distance having been levelled over in the summer of 1837, 
and the former in that of 1838. For the same reason it appears 
much better to divide the distance into stages and finish them 
one at a time, than to go over the whole in one direction, before 
returning upon any part of it; it being much more probable 
that errors depending on the state of the atmosphere will balance 
each other in the former than in the latter case. 

My own experience, therefore, leads to the conclusion, that 
no levelling can be expected to give a correct result, unless it 
be performed in opposite directions, and the mean of both re- 
sults be taken ; instead of depending, as Captain Lloyd appears 
to have done, on the consistency of separate sets of successive 
readings. I have myself invariably found (as that gentleman 
also did.) the agreement of these to be almost identical, both in 
the going and in the returning series, notwithstanding the great 
progressive difference of these two series of levels from each 
other ; of which progression not the smallest trace is discover- 
able in the separate columns of the same series. I have entered 
the more minutely into this subject, because I am not aware 
that any one has described, or even noticed the existence of 
such differences before; and should feel much interest in reading 
the statements of any experienced person who had been engaged 
in a similar undertaking, and had conducted it with sufficient 
care to render the /aw of the errors in any degree discernible. 


ee 


oe 


VOL. YIL—1838, c 


EIGHTH REPO 


18 


RT—1838. 


SKETCH OF THE NEW LEVELLING STAFF AND VANE. 


‘ 


Q 
m 


a Al 
ims 


——= 


Ss 


Slalabindinly 


<i omeage z 


oH nar 


TTS 


nC 


4 


id 
= 


i it al 


OO eee 


19 


Report on the Discussions of Tides, prepared under the direc- 
tion of the Rev. W. WHEWELL, F.R.S., by means of the grant 
of money made for that purpose hy the Association. 


Tue grant of money made at the last meeting of the Associa- 
tion, has enabled me to continue the discussions of tide observa- 
tions which I had already carried on for some time, and to ob- 
tain some results which I hope will be considered as valuable. 
I engaged Mr. Bunt to proceed with those discussions, accord- 
ing to methods which I had previously framed, and instructed 
him in the execution of ; and at present, his skill in the appli- 
cation of these methods being improved by practice, and stimu- 
lated by a great zeal and love for the subject, I believe his work 
(which I produce to the meeting,) will be found of. extraordi- 
nary accuracy and clearness. Iam fully persuaded that in con- 
sequence of tlie advantage of the plan pursued, and of the ex- 
cellent manner in which Mr. Bunt has executed it, the exact- 
ness of the results is of a most unexpected kind: for example, 
it is quite clear that the tables for semimenstrual inequality and 
for lunar parallax, (if not for declination,) obtained by our me- 
thods from a year’s observations, are as good as those previously 
obtained from the discussion of nineteen years’ observations. 
And the proof of this is found, not only in the regularity which 
the curves expressing the corrections exhibit without any arbi- 
trary improvement whatever, but also in the complete symme- 
try of the curves above and below the mean; the parallax cor- 
rection curves for 60! and for 54! (3' above and below the mean 
57’) are of exactly the same form. 

I have given an account of the results of these discussions in 
a memoir read before the Royal Society, and printed in their 
Transactions, entitled “On the Determination of the Laws of the 
Tides from short series of Observations,” being the ninth series 
of my tide researches. An account is also there given of the 
method pursued by Mr. Bunt in these discussions. I may men- 
tion here the questions of which I have in that paper attempted 
the solution. 

1. To which transit of the moon ought we to refer the tide ? 

2. How does a change of the epoch affect the semimenstrual 
inequalities ? 

3. How does a change of the epoch affect the (lunar) parallax 
correction of the times ? 

4. How does a change of the epoch affect the (lunar) declina- 
tion correction of the times ? 

c 2 


20 EIGHTH REPORT—1838. 


5. How does a change of the epoch affect the parallax correc- 
tion of the heights ? 9 

6. How does a change of the epoch affect the declination 
correction of the heights? 

7. Does the parallax correction of the heights vary as the pa- 
rallax ? = 

8. Does the parallax correction of the times vary as the pa- - 
rallax ? 

9. Does the declination correction of the heights vary as 
the square of the declination ? 

10. Does the declination correction of the times vary as the 
square of the declination ? 

11. Canthelaws of thecorrections be deduced fromasingle year? 

12. Are there any regular differences between the corrections 
of successive years? 

13. Do the corrections of different places agree in laws and 
amount ? 

The epoch here spoken of is that transit of the moon, anterior 
to the tide, and to which the tide is referred. The question ex- 
amined is, whether we obtain the closest accordance with the 
observations by taking a transit one day, one and a half day, or 
two days anterior to the tide which we consider. 

Although I have given the answers to these questions in the 
memoir in the Philosophical Transactions already referred to, I 
here lay before the Association the curves*, the comparison of 
which exhibits these answers, and exhibits indeed the result of 
my discussions more clearly and exactly than words can do. 

The careful examination to which we have subjected the Bristol 
tides, has shown us that there are scarcely any irregularities in 
these pheenomena which we have not reduced, or may not hope to 
reduce, to empirical laws, which laws constitute the first step to 
the solution of our great tidological problem, the explanation of 
the phenomena on hydrodynamical principles. I may add that 
the Report on Waves by Sir John Robison and Mr. Russell, inclu- 
ded in the reports of the seventh meeting of the Association, con- 
tains highly valuable materials, likely to assist us in the further 
prosecution of this subject. The unexplained residue, which, in 
our method of discussion, exhibits the difference between obser- 
vation and our tables as hitherto corrected, although it is small 
(upon the average two or three minutes in time, and as many 
inches in height in a tide of forty feet), is so far seemingly subject 
to some rule as to offer a promise of additional laws of cor- 
rection, and I should be desirous of discussing this residual 
quantity with such an object. 


* These curves are given in Plates 3, 4, 5, 6, 7, 8. 


wt 


ae 


a a i li a 


Account of the Progress and State of the Meteorological Ob- 
servations at Plymouth, made at the request of the British 
Association, under the direction of Mr. W. Snow Harris, 
F.R.S. (Drawn up by Mr. Harris.) 


Tur Meteorological Instruments, now in operation, are as 
follow : 
1. A Wind Gauge invented by the Rev. W. Whewell. 
2. A Wind Gauge invented by Mr. Osler, of Birmingham. 
3. The Barometer. 
4, The Wet-Bulb Thermometer. 
5. The common Thermometer. 

Professor Whewell’s instrument has been carefully attended to 
by Mr. Southwood, of Devonport. The results of the register 
accompany this communication. In consequence of Mr. South- 
wood’s removal from Devonport, the instrument, together with 
the wood work employed in its erection on his house, have been 
preserved: it will be again set up as soon as possible. 

Ten pounds, voted to defray the expense incurred in the erec- 
tion, repair, &c., of this instrument, since its employment after 
the Meeting at Bristol, have been paid to Mr. Southwood. 

The Wind Gauge lately invented by Mr. Osler, and exhibited 
to the Physical Section at the last Meeting at Liverpool, has at 
length been set up in a very excellent situation, at the house of 
Mr. Cox, Optician, Devonport. I am sorry that many unavoid- 
able delays in the manufacture, &c. &c. of this machine have in- 
terfered so much with its final completion, that I am unable to 
send any well digested result of itsaction. It is, however, now 
at work, and the Association will, I have little doubt, be amply 
rewarded for the trouble and expense incurred on account of it. 

Forty pounds was voted for this instrument ; of this 30/. has 
been paid to Mr. Osler. The attendant expenses on it have 
amounted to 20/. This includes the erection of an apartment 
of wood in which the instrument works, carriage from Bir- 
mingham, clock for the register, and sundry other expenses 
of a minor kind. 

"As the daily register must be carefully attended to it will be 
necessary to provide some slight remuneration for the person 
employed for this purpose. I should therefore feel obliged if 
the Committee would recommend the sum of 10/. for the ge- 
neral current expenses of the next year, should they so think 
fit. The machine appears an extremely valuable one, and when 
its register is taken in connexion with that of the barometer and 


29 EIGHTH REPORT—1838. 


the tides, &c., will I have no doubt afford very valuable infor- 
mation, since it registers the force and direction» of wind, with 
the amount of rain for every instant in twenty-four hours. 

The observations with the barometer are complete up to June 
last, all the observations having been reduced. I have not, 
however, been enabled to arrange in Tables more than those - 
of the year ending January 1, 1838. These observations being 
for one year only, I have thought it undesirable to write any 
detailed report of them. I may, however, be permitted to lay 
before the Section, as an approximative result, the march of the 
atmospheric pressure through one mean day, as shown in Table 
A, Plate 9, and deduced from 8760 observations ; from which 
some idea may be formed of the probable horary oscillation in 
this place, a subject of singular interest in meteorology. It 
appears by the result of the hourly observations for the year 
1837, that the horary oscillation amounts to 0°0144 of an inch. 

The hours of max. being 11 a.m. and 9 p.m. 
The hours of min. being 5 a.m. and 3 P.M. 

The line of mean pressure appears to be crossed 4 times in 
the 24 hours, viz. between 2 and 3 a.m., and between 7 and 8 
A.M.; between 12 and 1 P.m., and between 6 and 7 P.M. 


The deviations being in i the max. and min. A.M. 


and Onee ~ }for the max. and min. P.M. 


The neg. sign indicates the depression below the line of mean 
pressure, the pos. sign the elevation above it. 

The mean pressure by these observations, at 60 feet above the 
level of the sea, and at a temperature of 55° of Fahrenheit, is 
29°9532*. 

On the Ist of January, 1839, we shall have completed 2 years 
of these hourly observations, when general results, entitled to 
more confidence than those deduced from a single year, will 
probably be arrived at. It seems therefore desirable, in order 
to avoid too hasty generalization, not to enter further at present 
into this question. I avoid for a similar reason any further 
notice of the register of the hygrometric thermometer, the ob- 
servations being i in a state of progress only. 

The register of the ordinary thermometer, first contemplated 
by the Association at York in 1831, is, I am happy to say, 


complete for 5 years, and the observations are now reduced up to 
January last. 


= * A general type of the daily march of the barometer is given in Table A, 
ate 9. 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 23 


The general results, which accompany this communication, 
and which are exhibited in Plates 10, 11, 12, must be consi- 
dered merely as corrections of similar statements exhibited in 
my first report; the former being arrived at by a more exten- 
sive series of observations. It will be seen by an examination 
of Table III., Plate 12, that the approximations in calculating 
the hourly temperatures, on the supposition that they may be 
represented by parabolic absciss, are much nearer than in the 
similar table and plate before given. 

Of £50 voted for these observations, £35 has been spent in 
defraying the expenses attendant on them up to June last, 
leaving a balance of £15; part of this has been expended in aid 
of Mr. Osler’s wind-gauge. 

The labour attendant on the reduction and discussion of the 
observations made hourly with these last-named instruments 
being now very considerable, it becomes necessary to employ 
competent persons to assist in working out the ordinary arith- 
metical operations, &c. I would therefore suggest to the Com- 
mittee the propriety of recommending a sum not exceeding £40 
for this and other attendant expenses until the next meeting of 
the Association, when I hope to have the pleasure of submitting 
to the Section a full report of the results obtained from the 
respective registers. 


W. Snow Harris. 


32, Union Street, Plymouth, 
August 20, 1838. 


TABLE I. 


‘SUOTIVATASGO FZQ‘EF MOY ‘OIqV sty Aq “LEST “EBT “CEST “HES “CEST JO omngyvradio} UeOTN, 
180-6¢ 


310-25 | IPLSh | FSIS | LTL-%9 | 88L-LE | 08-19 | 010-29 GL8-8¢ | FGFS | 1ee-Sh | L6ch | O€8-FH | GLO-FH | SULIT 


Loe-66 | 690-FF | O1G-9F | GES-0G | IIL-1¢ L09-L¢ | 866-29 | F66-FS | 298-0G | SL9-FF | GSF-EP | 16L-Eh | 698-EF él 
ZEL-6P | L8q-FF | GOL-LF | 0ES-0F | 800-S¢ | 89-89 L2E-8E | 9EF-SG | 800-19 | FFL-SP | G6L-EF | O98-EF | Ga8-EP II 
z80-0¢ | LIe-Fr | 998-2 | 106-09 | S¢Ee-go | 88L-8¢ 880-66 | O16-S¢ | 189-[G | F9L-¢h | I88-F | 1S0-FP | COG-EP Or 
£9¢-09 | 69F-FF | S8e-Lh | TIG-1¢ | £e2-99 | 869-69 9€9-6¢ 12-9¢ | £89-2¢ | 99F-9F | PEEPH | E8G-FF | 8C6-EF 6 
92z-1¢ | GL9-FF | E88-Zh | e16-1¢ | 9BF-9G | FFI-09 | 696-09 EZL-LE | 6E6ES | 99%-LF | 808-FF | 6PS-FF | LE0-FP 8 
260:2¢ | 6L8-FF | GS1-8h | ZIE-Zo | L46-L9 | GLL-69 619-69 0&6 | FO9-SS | 66E-8F | G6G-SP | O€8-FP | 6&E-FP L 
10OL-2$ | SOL-Sh | GBPS | 960-9 | 9S9-8G | 189-69 690-49 | 869-09 | 009-£ | 808-6F | L1E-9F | OST-Sh | LIL-FF 9 
SZL-FS | £8¢-SF | LE8-8F | 690-FE | F96-6E | 860-59 142-69 | FE8-19 | LeG-6E | GPITS | LIe-LH | O88-Sh | LOL-SP ¢ 
¥ 
€ 
é 
I 


@ 

% e9z-¢¢ | GOL-9F | 6GL-6F | O68-9¢ | GSF-19 | 696-99 | GzP-99 688-29 | GEF-09 | 662-69 | PZS-RF | 6EO-LH | GOL-9F 

r. 620-95 | 628-9F | 19-0¢ | 10L-99 | 809-29 | 990-29 8ze-L9 | OL1-9 | BS0-19 | 8&8 | I8E-6h | EL0-8h | OSF-9F 

| 80-95 | Sec-ZF | S6B19 | S9T-LE | 69G-E9 | 06S-L9 1¥2:89 | OF6-19 | G9F-19 | SShFS | 900-09 | G9F-8F | OFG-9F 

S 826-99 | LFS-LF | 699-19 | L9T-8E | F6S-E9 | 099-29 6FLL9 | GZL-19 | 62819 | 6FG-FS | 9ZE-0G | 619-8P | COG-LP 

2 669-9¢ | P8L-Lb | FOF-TGS | B00-8E | 6IE-€9 16¥-29 | 8@¢-29 | 686-29 | €86-09 | LPL-FS | 9L8-6F | 996-8 GPO-LV 61 

be 6z6-¢¢ | £999 | 66-08 | S8e-ZE | FL9-Z9 | 088-99 | GPS-99 90-29 | G8E-09 | O19-ES | OLO-6F | BZELH | GEF-9P II 

pa 6LL-¥S | O18-SF | SI¥-6F | SeL-e¢ | G8E-19 | 146-99 gsg-c9 | e£F-29 | 0G8-69 | 88E-2o | Sc0-8F | Glch | CcI-SP OL 

i] 90826 | FLE-FF | GLO-8h | GFF-ES | 179-69 | OGE-F9 199-49 | PLG-19 | P6S-LE | 206-09 | G2F-9F | 9VG-FH | LS0-F¥ 6 

& 929-19 | 62GFF | ILL-9F | GLO-1¢ | S8%-L9 | 290-69 966-29 | 080-09 | SIZ-¢¢ | F9ESF | FESPF | 966-BF | COF-EF 8 

a OLL-0¢ | 908eF | O86-9F | S88-6h | OZL-GE | LL6-6¢ 962-09 | I8T-8¢ | 666-29 | €90-9F | FeL-er | L29-6P | 896-EF L 

3 ceggp | seer | Z80-9F | F2S-6h | SIL-FS | S6L-LE | 99F-8S 090-9¢ | 00Z-0¢ | GFL-FF | G8F-Zr | LOV-Gh | S8L-EV 9 
Z62-8F | L16eh | GFL-OF | Oe-6F | BeS-eS | 9EL-9E | $68.99 OL2-FS | S89-8h | 919-Eh | IL-ZF | P8S-Gh | P8G-EP g 
16@-8F | GLO-FF | 186-9F | 9LF-6F | SPLES | 886-99 1f¥-9S | 6649 | SLF-SF | O19-EF | L6E-2V | GLL-ZV | GEP-EP v 
eee-gr | 92z-FF | L0E-9F | ZZ9-6h | GFS-ES | CES-99 806-99 | 206-¢ | 629-8 | LeB-EF | L69-6F | 998-h | LES-EF € 
eg/-gh | Leehr | PSE-9F | 96L-6P | GLO-FS | 168-99 088:9¢ | FLL-FS | £90-6h | LEL-FF | OL8-Gh | 89GEP | £99-€F & 
C10-6b | 98@-FF | ZHS-9F | £80-08 | FIPS | STeLE L9G-L¢ | F2E-FE | FOS-6h | 99E-FH | LEG-EP | CGF-EF | S6L-EF I 
*suzayL ‘2a “AON "20 *ydag “any ‘syne ‘oune “AC ‘Tdy re] “qe ‘uee “noH 

(RLieiret|s -t ea es : - — < 
‘oury ‘duag, uray “OT 9°Id 99S 
<< "IVI IpOYA yy oF puv ‘JE81 S9E8I 


N ‘cee Pest “EESt STVaA oy} JO YUVOW youve 1ofJ NOP Yovs JO ainyeladway, UBoJA, OU} SUIMOYG *] ATAVY, 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 25 


See Plate 11. 


Tasxe II. Showing the Mean Hourly Temperature for each of 
the Seasons, viz. Spring, Summer, Autumn, and Winter, 
for the Years 1833, 1834, 1835, 1836, 1837. 


Spring. Summer. Autumn. Winter. 


45°709 56:369 50:348 43°875 
45:353 55°982 50-056 43°749 
45-018 55°648 49-926 43°539 
44:827 55-493 49-817 49-427 
44:857 55-774 49-677 43-262 
45613 57-240 49-908 43°179 - 


47-399 59-418 50-428 43°217 
49-534 61-714 51-693 43°563 
51-743 63°487 53°703 44-290 
53264 64:777 55-513 45-562 
54334 65:676 56-836 46°873 
55°185 66:323 57575 47-697 


55'535 66-479 57°810 47-888 
55308 66°624 57:253 47-649 
54:757 65°818 56613 47-127 
53'919 65-193 55°524 46°417 
52'659 64:108 54:287 15°458 
51-239 62°815 53°359 44-992 


49°765 61:313 52°571 44-689 
48-671 59°79 52-075 44-420 
47-812 58-625 51-607 44-227 
47-109 57°929 51-207 44-084 
46°649 57-448 50°882 43-989 
46°166 56°73 50°620 43-903 


49-684 60-867 52-912 44:878 


Mean 52'085. 


26 EIGHTH REPORT—1838. 


See Plate 12. = 


Tasir III. Showing the Mean Annual Hourly Temperatures 
for 1833, 1834, 1835, 1836, 1837 at Plymouth, as ob- 
served and calculated on the supposition that they may be 
represented by Parabolic Abscissz. : 


Hours. Obs. Temp. Cal. Temp. | Diff. 

z 4 30 48391m | 48391 | 0-000 

bela 5 48:391 48-456 | — 065 

3 6 | 48985 | 48976 | + -009 

£ 7 | 50:110 50-015 | + -095 

vai 8 | 51-626 51559 | + -067 

S 816 152-078 52-078 | 000 

f 9 53-306 53-468 | — -162 

2. | Jo 54779 | 54982 | — -203 

ae 11 | 55-929 56-062 | — -133 

oma I ES | 56695 56-712 | — -017 
PAREN | -M56-928 56-928 000 | 
nT a | | 

e 2 56-708 56-794 | — -086 

a 3 56-079 56369 | — -290 

3 4 55-263 55-716 — 453 

5 | 54-128 54-773 — 645 

as 6 53-101 53-560 | — 459 

a 7 152-093 52-093 000 

8 51-236 51-342 | — -106 

9 50:567 50-689 | — “112 

< 10 50-082 50117 | — -035 

a 11 49-742 49-627 | + “115 

5 12 49-355 49-218 | 4 137 

5 1AM. 49-075 48-891 + 184 

Eh 2 48-785 48-646 | + :139 

bs 3 48583 48-483 | + -050 

: 4 m 48391 48-401 | — -010 


—_ 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 27 


TaBLE IV. 
See Plate 10. 


Summer | Winter 
Months. | Months, 


| Summer ‘Winter | 
Hour. Months, | Months, |; Hour. 


a a | | 


oe 52898 | 45-251) 1 63-218 | 50-638 
2 52526 | 45-044, 2 63-176 | 50-240 
3 52:208 | 44:857 || 3 62-475 | 49-684 
4 52-051 | 44-730 || 4 61-711 | 48:815 | 
bg 52-196 | 44-589 || 5 60-491 | 47-764 
6 53-364 | 44-607 || 6 59:068 | 47-134 | 
7 55-406 | 44-815 || 7 57-536 | 46-632 
8 57-742 | 45510 || 8 56-161 | 46-311 
pay 59-817 | 46-794 || 9 55-117 | 46-018 
| 10 61-243 | 48-315 || 10 54-431 | 45-733 | 
11 62-282 | 49577 | 11 53917 | 45-567 
12 p.m. 62994 | 50-295 || 12 53-324 | 45-386 


| Means | 57:306 | 46-850 
Mean 52-078. 


Tape A, Plate 9. Showing the Mean Pressure of each Hour 


for the Year 1837. 

‘ 

‘ Hour. Pressure. Hour. Pressure. 

[Mah S| eee 

q lao. 29-9558 1 pM. 29-9492 

: 2 29-9556 Aaa 29-9467 
3 29-9492 Ol vee 29-9440 
4 29-9474 4 29-9442 
Dae 29-9467 5 29-9463 
Goss 29-9497 6 29-9484 
7 29-9519 “(MERE 29-9547 
8 29-9555 8 29-9596 
ees 29-9572 9... 29-9627 
10... 29-9567 10... 29-9628 
10 ars 29-9580 il ces 29-9621 
]2 aes 29-9545 Ue ee 29-9590 

Mean 29-9532 


28 EIGHTH REPORT—1838. 


Tables, &c., of Observations made with Professor WHEWELL’S 
Anemometer at Mount Wise, Devonport. From November 
1837 to June 1838, inclusive. 


These Tables comprise :—1. The observations as daily re- 
corded. 2. The reduction of these observations. 3. A sum- 
mary Table, in which the general result is condensed. Lastly, 
The charts and general type of the wind, as shown by the re- 
spective reductions and summary. 


Plate 13, contains the general summary: the month of No- 
vember 1837 is coloured blue, and marked 11 ; December is red, 
and marked 12 ; January 1838 is again blue, and marked 1. The 
remaining months continue to be marked 2, 3, &c. The breaks 
in the continuation of the lines show when the instrument was 
under repair. The direction of the wind is here only recorded 
and indicated by dotted lines. 

The black dotted lines show the resultant magnitude and di- 
rection for each month ; the five black lines are continued re- 
sultants, viz., that marked 1, 2, is the resultant of 11 and 12, 
that marked 1, 2, 3, of 11 and 12, and so on to the last marked 
1 to 8; which is the resultant of 8 months. The scale of this 
Plate is that of the 400 equal parts to the inch. : 


x 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 29 


Indications of Whewell’s Anemometer at Mount Wise, 
Devonport, 1837, 1838. 


NovEMBER, 1837. 


WwW. Nw. E. 
12 3 15 lis} 4 4 
Nw. WSw. W.S.W 
11 5 16 lig} 14 4 
WNW. W.S.W 
3 3 |laol 25 25 
W.N.W lws.w. Ww 
0 o jail 18 13 28 
SSE S§ W.sawv. SW... 
1 26 37 lla} 10 28 38 
S. S.W.  S.S.W. 
42 49 les] 21 33 5A 
| | S.S.W. W.S.W. S.W. 
| 2 10 12 |\24| Under repair. 
Pew CW. Sho RoW, 
9 6 15 ||25| Under repair. 
SW. S.W. 
5 5 10 a6, 0 0 
W. WS.W. NW. 
Q 2 Ie7| 33 5 38 
W.S.W. | W.s.w. 
15 15 las} | 8 8 
W. NNW. NNE. W.N.W. NNW. 
9 9 12° | 30 la) | 5 7 12 
NNE. Pat SW. 
3 3 |isol_—«12 12 
E. ay 


11 1] 


30 _ EIGHTH REPORT—1838. 


DecrEMBER, 1837. ~ 


Wow. SW. 
1 3 24: 27 \16 Under repair. 


— | WU“ 


5 15 15 ||20 Do. 


_——— | $< — $s 


14, O 0) 


15)" \"65 65 |31 88 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 31 


JANUARY, 1838. 


E.S.E. S.E. E.S.E. 
96 33 105 = |234 


S.E. 
Under repair. 


9 2 
4 


{ 


Ah! Om 


—— 


to 


32 EIGHTH REPORT—1838, 


FreBruary, 1838. “ 


E. E.S.E. 
1} Under repair. 15; 240 


a nt | | | | 


N.E. E.S.E. 
2 : 16) 210 


NE. Ne ES.E. 
3 3 17| 103 


N.E. W.N.W. 
4 7 18} 22 


E. E.S.E. 


| 49 49 25} 40 


E.N.E. N. S. 
12). 25 17 42 26) 63 


E.N.E. 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH « 33 


Marcu, 1838. 


esr s 
77 8 15 33 
f S.E 
{2 5 22 
| SE, 
jal 5 5 
a a a ee eas OTs 
)| SE WS.W 
4 30 5 53 
W.S.W. N.W 
5| 18 6 23 
Tl NW. w. ia N.N.W 
lel 22 31 5 19 
i W.S.W. 
|7 14 16 
P| Nw. ‘e 
|s| 14 3 
| 1 SS Fines SE 
| | W.N. N.N.W. W.N.W. 
jo 6 16 21 
, S. as SE. 
o| 29 i 7 
S. S.E 
| il} 10 21 5 
| | ESE 
a 2 0 
| w.s.w. 
3} 23 0 
cw. |. 
10 3 
w. 
15 0 
W.N.W 
ligl 5 5 


VOL. VII.—1838. D 


34 EIGHTH REPORT—1838. 


APRIL, 1838. : 
E.S.E. W.N.W. 
] 22 22 16 18 18 
E.S.E. W.N.W. 
~\ aoa) 5 ||17|\Under repair. 
N. N.W. i 
3 8 8 18 x + 
N.W. N.W 
4) - 0 0 |19 7 
W.N.W N. 
5 0) 0 {20 = 
W.N.W. W.S.W. N. 
Birt 15 20 |'21| Under repair. 
W.S.W. N. 
7 33 33 ||22 “6 
W.S.W. N.E. 
Si roe 22 ||23 x 
| W.S.W. NE. 
©) Remeal peo) 8 24 9 
on | NANE. 
10; 6 6 |25|Replaced. 
S.S.W. N.N.E. N.E. 
11 3 3 26 6 10 
ha (ON. NINE. ENE. 
12 3 3 127 8 + 
S i 
13 5 5 28 3 2 
W.S.W. N.N.E N. 
14 16 16 ||29| 27 8 
N.W W.S.W 
15 6 6 |30 40 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH, 


35 


May, 1838. 
WS.W. W. E.S.E. 
1 10 45 Wf 
sw. SS.W ESE. W. S, 
7) 18 43 3 10) O 
| sw. oy ae ee 
31 69 25 40 
$.S.wW.  W SE. S.S.W 
4. 15 98 30 46 
|| NE S.S.W. S. W. N.W. 
3| 78 1 19 0 0 
| W.S.W. S.S.W. E.S.E. Ss. S.W. N.N.W 
| 6 91 13 go 1 2 1 
| | ESE. | ow. Ww. 
Ve Q 15 
| | BSE NNW. 
‘sl 98 6 
SE. We Bo Se 
81 9 3 5 
S.E. Le Se 
51 26 
S.E. S.E. 
110 87 
SE. W.S.W bea 
19 9 ee ii 
E.N.E fijsen <i ccw. 
41 8 ee 
SNNE S.W. 
4 30 31 
NNE. SE. rt gow. 
8 39 O 
}) | E.S.E Saille 


36 EIGHTH REPORT—1838. 


JUNE, 1838. 


S.W.  E.S.E. 


pew. 2 Wo Bae 
a 10 15 


— | —_— 


J. A. SouruHwoop. 
L 


| 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 37 


The following calculations with the accompanying Plates re- 
present the result of observations made at Plymouth, with an 
Anemometer of Mr. Whewell’s construction. This instrument 
gives what Mr. Whewell calls the integral effect of the wind, 
namely, a space proportional to that which a particle of air would 
pass over in each day in consequence of the wind, taking into 
account both the strength of the wind and the time during which 
it blows. These integral effects being put together according to 
their directions, each day beginning at the end of the preceding so 
us to form a continuous line, as is done in the Plates, we obtain 
the path of the wind for each month, or for a longer time. The 
annual path of the wind at each place will have, it may be ex- 
pected, a general similarity in different years ; and the mean 
form to which the annual path thus approximates is called the 
type of the wind for each place. 

A description of the Anemometer, of the mode of using it, 
and of the process of reducing the observations is given in the 
Transactions of the Cambridge Philosophical Society for 1837 ; 
vol. vi. Part II. 


EIGHTH REPORT—1838. 


38 


"N [ANON | “AUN 


“MN M 


“M 


“ASM. | TANS 


“M'S’S | 'S 


‘aS'S 


aS 


‘an’n| ‘N | 


“LEST 


“Ada WAAO NT 


*suoupasasygQ suparasd fo wor)snpayy 


aie Esai 

“a “AN'N'N 
"WSL “UIST “AON 

6 or 

“AN “T'S'S 
“NST "N98 “AON 

Meese 

“N'A ON 

(19 “WIF AON 


39 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 


“NP CAAN'N | “AVN | “ANAL “AA PANS" AA | “AAS 


“M'S'S 


‘g f-aes's 


¥% ee 
“A'S “AL'S"AN 
ST 0Oq, “YILG “AON 


WS PUSH) a “ON | ON'NG 'N 


£ becassihes saith a eee sdeamek: NF! tae con 


sé 4 
“ASS CANS" AA 
“PLES “36 “AON 


EIGHTH REPORT—1838. 


86} “AVS 
6L | ASA 
16 OF 
1é OF 
A'N FL 


6 


“AUN | CAUNUAN PAN PF AAS“AA | “AL'S 


83} “a 

a ae 
62 | “a 

¢ | ‘IN 
¢ JaN'a 
6r} 9 

16 

y | 9 


"A'S'S P'S PWS'S| “WS | WS a] “a bana 


Iz 88 
‘MSM 'S 
‘UIP URE “ISTE “0a 


pue 


“S “WICT 20q 


| 
ni | 


“IL “HP “99 


4\ 


cor aL 


ee ee oa 
"pigs “Wg “WEL 


"N PCAA'NUN | “AAN | “AANA AA PASAY] CAA’ 'S PUSS) WS Pasa] “aA PaN'a, “AN “A NONE ON 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 


se 

‘N 
del Gane ta 
“ANAM “AN'S“AL 
6 = Wh RIT 


og GF 
"T'S act 
Usp AUP “WITT “49d 


EIGHTH REPORT—1838. 


42 


“N PCAUNUN | AUN | ACNOALT AA PANS) CAL'S | CASS JS PASS] “HS | WS ay a jana “ON | QN'N] ON 


ely ‘Ss 9¢ | “a 


s Zi asa Ts [1 
I | as ‘T's'a] 0¢ 
; € ae |e 
re ¢ ¢ 
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° 
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= ‘9% ‘UST Ie 
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(=) 
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| 
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‘TS Ss 
“WST = “WOT “Ae 


“NP ANN | “AN | “ANCA “ay | cAS"AN “A'S | “AVS'S | -as's| ‘aS _ fxrsa| <s UN'S “TN aii 


= sa ee 


EIGHTH REPORT—1838. 


44 


x Ra ete at 


PAA NN “HNN 
"1362 “19% WAdy 


ESie 8 
“AN ‘N 
‘THOT ‘prg judy 


“MCNTN | CACN [CANON CAA PANS" AN] CANS | CASS [CS [OS'S] “O'S [ASA] A PONG) “ON |ON'NI ON 


45 


S | 2s1 
= "Ss | £92 
5 ‘N | SOT 
S See 
= ONG] OT 
is “a'N | FS 
Pa “a'N'N] GE 
& 
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v4 
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e 84 | 0€ ‘WI8T “Ig Av 
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2 ez} os | 48 | 8g 92 oF 
a “A CAN'S"AN 
a sz | OL 69 cI aes 
ica} cr OV 81 €P WF Ae “0g Tady 
= 


“ TaNN | CAAT | CAMA ca | canst. | “AMS | cans’ | *s [ars’s| cars “TN |"SNCN] CN 


29 EEE Sa 


cOIPa N'A “UN'S PP 


. SIt| ° 9] LIT 
30 % a 
oO 18 9 : “a 
"7. 9z cg ~ 
! ¢ € Ill "96e =" UIGS ACW 
§ 
a get] *s 
i 
re ral ‘N 
Re 
E StI} “Ss 
— I 
a 99 
12 | ‘a's ‘E'S | 12 
Doe, ss: 0g 
=e bB Eakttos 
< PATNA = “AAS 
iy Ay ied 0g Chey A ND 
"N PCACNUN | “AUN |] AUNT * ‘gs f'as’s| ‘a's |‘a's‘a] “a bana “TN |G°N'N x | 


46 


47 


id cI 


TSa ‘MS's 
yypz oun “6% Ae 


METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 


S PUSS! WS LS Ay A PANG) “ON ON GE ON 


ee te a athe 
Oa ee or ne 


Ses ee ~ -e 
. co 


EIGHTH REPORT—1838. 


SUMMARY TABLE. 


N s E. Ww 
1837. Noy. 4to Nov. 7, 1837. ) rod ae 25 
8, 15. fe 99 ee 51 
15 4, 18. 22 tr 21 6, 
198. 23. a? 89 an 119 
Nov. 27 ,, Dec. 1. aA 39 =20 50 
Dec. 4,, 11. 8 a. 28 
15 ee 65 a at 
31 ,, Jan. 4, 1838. Ss 540 se 47 
1838. Jan. 8 ,, By oes 105 349 
Feb. 11 ,, Mar. 4. 3% 705 917 Sei 
Mar. 4 ,, 9. 17 99 
10 ,, 12. oat 53 15 vs 
1B;,; 26 46 215 
26 ,, April 2 A 13 36 3 
April 3,, 16. ae 26 zea 112 
abe 29. 65 39 
30 ,, May 4. a 134 as 203 
May 5,, 18. te 152 352 FF 
19 ,, 29. rh 136 Es 28 
25 5, 29. as 49 251 ie 
29 ,, June 24. See 351 ee 283 
167 2558 2008 1232 
a uu ———_—_ ———Y 


South 2391. East 776. 


C 49 ] 


A Memoir on the Magnetic Isoclinal and Isodynamic Lines 
in the British Islands, from Observations hy Professors 
Humphrey. Lloyd and John Phillips, Robert Were Fox, 
Esq., Captain James Clark Ross, R.N., and Major Ed- 
ward Sabine, R.A. By Major Evwarp Sasine®, R.A., 
F.R.S. 


Ar the meeting of the British Association, held at Cambridge 
in the year 1833, a resolution was passed, recommending that a 
series of determinations of the magnetic dip and intensity should 
be executed in various parts of the United Kingdom. 

Early in 1834 Professor Lloyd, who had attended the meet- 
ing at Cambridge, proposed to me to unite with him in carrying 
the recommendation of the Association into effect as far as re- 
garded Ireland. I was at that time employed on the staff of 
the Army in the south-west district of Ireland, and found 
it not incompatible with other duties to undertake that portion 
of the island. Our observations were continued at intervals 
throughout that year, and until the autumn of 1835, in the sum- 
met of which year we were joined by Captain James Clark Ross. 
A report of our operations, drawn up by Professor Lloyd, was 
made to the British Association, assembled in that year in Dub- 
lin, and was printed in 1836 in the fourth volume of the Asso- 
ciation Reports. A re-calculation of the Irish results, incorpo- 
rating the observations which have been made since in that part 
of the United Kingdom, has been furnished by Mr. Lloyd, and 
occupies its appropriate place in this report. 

Mr. Robert Were Fox, who was present at the Dublin meet- 
_ jing in 1835, brought with him an apparatus for magnetic ob- 
servations on a new construction of his own invention, with 
which, after the meeting, he made several observations of the 
dip in the course of a tour in the west and north of Ireland. 
These observations, with others made on his return through 
Wales, were published in 1836, in the report of the Royal Po- 
lytechnic Society of Cornwall for 1835. Several of these ob- 
servations were made in houses, and were consequently liable 
to disturbing influences. Mr. Fox has selected eight deter- 
minations of the dip in Ireland, and nine in Wales, as free from 
objection on this account; and with his permission they are 
now incorporated in the present report. 

Having obtained two months leave of absence from military 
duty in the summer of 1836, I employed them in extending the 
survey to Scotland, by observations at twenty-seven stations dis- 

VOL. vil.—1838. E 


50 EIGHTH REPORT—1838. 


tributed over that country; forming the basis of a memoir on 
the Scottish Isoclinal and Isodynamic lines, which was printed 
in the fifth volume of the Association Reports, and published in 
1837. 

In the same summer Professor Lloyd commenced the mag- 

netic survey of England by a series of observations at fourteen 
stations, principally in the midland and southern districts ; these: 
observations have not been hitherto published, and will be found 
in their place in the present memoir. 
» The interest which had been excited at the meetings of the 
British Association by the Irish and Scotch Magnetic Reports, 
induced Professor Phillips to provide himself with an apparatus 
for the dip and intensity ; having particularly in view the inves- 
tigation of the influence which he deemed it possible the con- 
figuration of the surface, or the geological character of the di- 
strict, might have on the position or on the inflexions of the lines 
representing these phenomena. In the summer of 1837 Mr. 
Phillips visited and observed at twenty-four stations in England, 
chiefly in the northern district ; these observations are now first 
published. 

In the same summer Mr. Fox determined the dip at twenty 
stations in the north of England and south of Scotland; and in 
the summer of 1838 at eight stations in the south of England, 
extending from London to the Scilly islands; at some of the 
latter stations he also observed the intensity: these observa- - 
tions form part of the present memoir. 

In August 1837 Captain James Ross commenced a series of 
magnetic observations, which he continued almost uninterrupt- 
edly until the close of 1838; they extend over England, Ire- 
land and Scotland generally, and comprehend fifty-eight sta- 
tions. His observations of the dip and of the intensity are in- 
cluded in the present memoir. 

Lastly, between August 1837 and October 1838, I have taken 
advantage of an interval between military duties, to observe the 
dip and intensity at twenty-two stations, distributed for the 
most part round the coasts of England and Wales, and extended 
into Ireland and Scotland for the purpose of accomplishing a 
more complete connexion of the different series. 

It has been the wish of the four gentlemen connected with 
me in this undertaking, that I should draw up the memoir of 
what our joint labours have accomplished. Our observations 
have been now carried over the whole extent of England, Ire- 
Jand and Scotland ; and may be considered in their combination, 
and by their extent, to obtain, in some measure, the character 
of a national work ; presenting to the immediate requisitions of 


MAGNETIC SURVEY OF GREAT BRITAIN. 5] 


science, the actual state of the phenomena of the magnetic dip 
and intensity in the British islands; and furnishing for distant 
times the means of a comparison, whereby the secular changes 
of these elements may be correctly judged of. 

- It has been found convenient to divide the report into two 
parts, the first‘comprising the observations of the Dip, the se- 
cond those of the Intensity. 


Division I.—Dip, 


_In the memoir on the magnetical observations in Ireland 
(British Association Reports, vol. v.), Mr. Lloyd has noticed 
the discrepancies which have been occasionally found in the re- 
sults of observations of the dip made at the same station with 
different instruments. The observations of Captain Ross at 
Westbourne Green, which are there related, place these discre- 
pancies in the strongest light. Captain Ross employed eight 
needles, making from eight to ten observations with each, each 
observation consisting of eighty readings; i. e. of ten in each 
of the eight usual positions. The dip at Westbourne Green, 
resulting from each of these needles considered separately, va- 
Tied from 69° 01''5 to 69° 42''6. On these discordances Mr. 
Lloyd remarks as follows: ‘‘ Thus it appears that there is a dif- 
ference amounting to 41' in the results of two of the needles 
used; and that the difference is very far beyond the limits of the 
errors of observation, will appear from the fact, that the extreme 
difference in the partial results with one of these needles, B (1), 
does not amount to 4/4, while with the other, (P), the extreme 
difference is only 2'. In fact, it so happens, that these very 
needles which differ most widely in their mean results are those 
in which the accordance of the partiad results is most complete. 
Of the eight results obtained with needle P, there is one only 
which differs from the mean of the eight by a single minute ; 
and yet the mean of all the observations with this needle differs 
by more than 20! from the mean of any of the others, while its 
excess above the mean of the entire series amounts to 25!. 

‘These differences cannot be ascribed to any partial mag- 
netism in the apparatus, for three of the needles (I, P and R) 
were of the same dimensions, and were used with the same cir- 
cle, and yet their results, as we see, are widely discordant. We 
must seek then in the needles themselves the cause of these 
perplexing discrepancies; and we are forced to conclude that 
there may exist, even in the best needles, some source of con- 
stant error which remains uncorrected by the various reversals 

_ usually made; and that accordingly no repetition of observa- 
E2 


52 EIGHTH REPORT—1838. 


tions with a needle so circumstanced can furnish even an ap- 
proximation to the absolute dip.” r 

I may add to the preceding remarks, that the discordances 
thus noticed far exceeded the limit of either diurnal or irregular 
fluctuations of the dip in England, as far at least as these phee- 
nomena have hitherto been the subject of observation. 


An attentive consideration of the various sources of error to . 


which dip observations might be liable,—of those which were 
already guarded against, and of those which still remained un- 
provided for,—induced the belief, that a considerable part at least 
of the discrepancies in question, and of similar discordances ex- 
perienced elsewhere, were occasioned by the axle, on which the 
needle rests on the agate planes, not being perfectly cylindrical. 
Careful observers on the continent had already noticed defects of 
workmanship in this respect ; and had been Jed thereby to have 
needles made, in which the axle, instead of being permanently 
fixed to the needle, was secured in its place merely by strong 
friction, and could be taken out, turned a portion of a circle on 
its own centre of rotation, and replaced; thus enabling the 
points of the circumference of the axle in contact with the sup- 
porting planes to be varied in successive trials. At Captain 
Ross’s desire, Mr. Robinson undertook to have four needles of 
this description made, for one of which Mr. Frodsham, whose 


chronometers are so well known for their excellence, undertook 


to make the axle. On these needles being completed, they were 
tried each in four different positions of the axle,—that is to say, 
the axle being secured, an observation of the dip was made in 
the usual manner, and with the usual reversals :—the axle was 
then removed, turned on its own centre a portion of a circle, 
replaced, and the dip again observed :—in like manner, a third 
and fourth change was made in the position of the axle, and the 
dip observed at each. The process thus described was twice 
repeated with each needle. Of the four, Mr. Frodsham’s axle 
proved the best ; but the trial clearly manifested in all the im- 
perfection which had been apprehended. The results with the 
needle furnished with Mr. Frodsham’s axle are given in the 
subjoined table, where that needle is designated as No. 1. 
With this experience Mr. Robinson undertook to replace the 
axles of the other three needles with three which should be the 
workmanship of his own hands. On these being tried, the dis- 
crepancies of each in the four positions were less than of any of 
the four axles in the former trial, but still amounted to several 
minutes. The results of the best of Mr. Robinson’s axles have 


been selected for illustration, and are those of No. 2. in the sub- 
joined table, 


MAGNETIC SURVEY OF GREAT BRITAIN. 53 


Tasxe I. 
Trials of the Axles of the under-mentioned Dipping Needles. 


Needle 1. Frodsham’s axle. Needle 2. Robinson’s axle. 


weaganet| RSE: | arom nin. | alone] e FM | som 

1 { ars 345 sila) 1 { ss 425 69 28-6 

2 {\6 0) 447/69 526) 2 {|9 2 159 | 69 27-8 

3 { ie 3r¢ | 69 133), 3 { ie Fo) | 69 26:3 

4 { on O68! 69 549] 4 { ahs Oen | 69 29-2 

Moths Agle enn } 69 .33-05|| “orth axlen ne } 69 265 
Experimentrepeated. Experiment|repeated. 

1 { bee 51g (09 189] 1 4 ae 35 | 69 185 

2 { nia pra | 70 015 || 2 { aa $31 | 69 295 
3416 Go 471 (09 263] 3 {| 2 G2 208/69 23 

4 {|¢ OO eae | 69 489|| 4 ‘is OF Oat | 69 29-6 

| Mean of our positions } 69 38-9 Mean of four positions 1 69 25-15 


of the Axle ......s00- of the Axle .........0.. 


The observations having been made in a house, the dip ob- 
served is not the true dip in London. This is immaterial, as the 
object of the experiment was solely the agreement or otherwise 
of the results in the different positions of the axle. 

Had the axles been perfect, the same dip should of course 
have been given in all positions of the axle: we perceive, how- 
ever, that the differences in the one needle amount to above 40’, 
and in the other from 7’ to 11’. The results of these experiments 
fully impressed Mr. Robinson with the necessity of employing 
more effectual means for ensuring a true figure to the axles of 
dipping needles ; and in several which he has since made, and 
which have been carefully examined, he has proved successful. 

Having exhibited the discrepancies of the earlier needles, it 
may be satisfactory to show the improvement in some of the later 
ones ; and for that purpose the following observations are given 


‘with needles which were afterwards employed in the general ob- 


servations of this report. The axles of these needles ; being made 


54 EIGHTH REPORT—1838. 


to revolve, were successively tried in four positions, which were, as 
nearly as could be guessed, a quarter of the circumference apart ; 
had they been precisely so, the needle must have rested on the 
same points of the axle, in the Ist and 3rd positions, and in the 
2d and 4th, (as the poles are reversed in each observation), and 
the results in those positions should have been the same ; but 
as this can have been only approximately done, each position may 
be considered as bringing a different set of bearings into play. 
The observations were made as before, in Mr. Robinson’s house, 
and have therefore no reference to the true dip. 


Tas_e If. 


Trials of the Axles of the undermentioned Dipping Needles. 
London, June and July, 1838. 


Positions Ist Pair, 2nd Pair. 3rd Pair. 
Khe | | eee ee eee 
Axle. R. 4. R.5. R. 6. By W., 1. W. 2. 
1 69 44.9 | 69 435 || 69 39-8] 6 434 || 6 484 | 69 489 
2 | 69 43:8 | 69 39-9 | 69 40-4 | 69 40-8 || 69 50-4 | 69 46-0 
3 | 69 381] 69 462 69 41-4 | 69 47-0 || 69 49:5 | 69 46-7 
4 | 69 434] 69 44-8 || 69 368 | 69 38:8 || 69 53:5 | 69 47-3 
Mean...) 69 42:5 | 69 43-6 | 69 40-0 | 69 42-4 | 69 50:5 | 69 47-4 


In all these six needles a great improvement was manifested. - 
The greatest difference occurring in any two positions of the 
axle of any one of the six needles is 8’, including of course ac- 
cidental errors of all kinds. 

The imperfection of the axle is a source of error, from the 
effects of which, if it exists, the results can scarcely be freed 
by any mode of conducting the observation ; at least, without 
going through the very tedious operation of observing round 
the circumference of the axle on every uccasion. When accu- 
racy is desired, therefore, only such needles should be employed, 
as have been ascertained by preliminary trial to be nearly 
free from this defect. Needles with revolving axles are easily 
tried. Those of the ordinary description, in which the axle is 
permanently fixed, may be examined by observing the angle of 
inclination shown by the needle when the circle is turned in 
different azimuths from that of the magnetic meridian, and by 
computing the dip by means of appropriate formule, from the 
angles shown in the different azimuths. If the axle is perfect the - 
dips so computed should all accord. In the azimuths intermediate 
between the magnetic meridian and its normal plane, the needle 
rests successively on all points of the axle comprised in a por- 
tion of the quadrant equivalent to the complement of the dip ; 


MAGNETIC SURVEY OF GREAT BRITAIN. 55 


and the corresponding points of the other three quadrants be- 
come in turns the points of support in the customary processes 
of the reversals of the poles and circle. If this operation is 
gone through at any part of the earth on or near the line of no 
dip, the whole of the quadrant is thereby subjected to exami- 
nation. In such situations, consequently, this method affords 
the means of examining the whole circumference of the axle ; 
and in all other localities, as much of the circumference as 
ainounts to four times the complement of the dip. Whatever 
portion in the latter cases remains unprovided for, may be tested 
by converting the needle, temporarily, into one on Mayer’s 
principle. ‘This can easily be done by the application of a little 
wax ; the quantity of which may be varied at pleasure, so as to 
correspond with the weights of different sizes, by which, in 
Mayer’s method, the angles of inclination, from which the dip 
is computed, are varied in successive observations. By one or 
other of these processes the true dip at any station can be 
obtained from any and every inclination of the needle; and every 
part of the circumference of the axle can consequently be tested. 

In what has been said, it has been presumed that there 
is no magnetism in the circle itself, as, should such exist, it 
would certainly become the source of discordance in the results 
derived from different azimuths, or from different weights, in- 
dependently of any defect in the axle; and so far, therefore, 
the agreement of the results in such trials (should they be found 
to agree) indicates with great probability the freedom of the 
circle from magnetism as well as the goodness of the axle. But 
Mr. Lloyd has employed and has described in a subsequent 
part of this report an independent and much more delicate mode 
of examination for magnetism in the circle. 

The customary provision of two needles for each apparatus 
does not alone afford security against the errors which may be 
occasioned by either of the defects to which I have now al- 
luded. In respect to the axle, if the results of the two needles 
are accordant, it is thus far satisfactory, that it certainly is not 
probable that both needles should have accidentally exactly the 
same imperfection ; but if they differ, the observer has no guide 
as to which is to be preferred; whilst their mean result cannot 
usually be more than an approximation to the true dip, for it is 
also improbable that the two needles should have an exactly 
equal amount of error in opposite directions. As a means of 
detecting magnetism in the limb, two needles are of no more 
avail than one; because both are directed to the same point of 
the circle when observed with at the same station, and, if a dis- 
turbing influence exists, both will be subjected to the same error. 
If, however, one of the needles is temporarily fitted on Mayer’s 
plan,—and the dip is obtained in successive experiments from 


56 EIGHTH REPORT—1838. 


ares differing very widely from each other, and distributed ge- 
nerally round the whole circle,—and if the results in such case 
accord well with each other, and with those of the unweighted 
needle,—it may be concluded that there is no disturbing influ- 
ence in the limb. 

Those who are desirous of making accurate observations, 
should regard the preliminary examination of the axle and limb 
of the apparatus they employ as an indispensable precaution. 
When these points have been satisfactorily examined, and the 
instrument is found correct, the natural magnetic direction, 
both in regard to azimuth and inclination, is the most advan- 
tageous for the observation of the dip. It is in the preliminary 
examination, that the method devised by Mayer, and that of 
varied azimuths, are chiefly valuable*. 


It may now be satisfactory to exhibit the observations that 
have been made at Westbourne Green in the years 1837 and 
1838 with different circles and approved needles. (Table III.) 
The greater part of these instruments were made by Mr. Robin- 
son since his attention has been particularly directed to the cir- 
cumstances above noticed; and those who will take the trouble 
to compare their performance with that of the several needles 
employed by Captain Ross at the same station in 1835, 
will have an opportunity of judging how great an improve- 


ment has been effected in our English dipping needles since ~ 


that period. Of the two other instruments not made by Robin- 
son, one was made by Gambey for Captain Fitz Roy, of the 
Royal Navy, and kindly placed by that officer at my disposal, to 
be employed in the observations in this report. The excellence 
of the dipping needles of this artist is too well known to need 
any comment in this place. The other instrument was made by 
Mr. Thomas Jordan of Falmouth, the artist employed by Mr. 
Fox to make the dip apparatus on the construction which he 
has devised, and which is described in a paper in the 3rd vol. 
of the ** Annals of Electricity, &c.’’ Mr. Fox’s needles do not rest 
on a cylindrical axle supported by planes, but the axle is ter- 
minated by exceedingly fine and short cylindrical pivots, which 

* The needle employed by Sir Everard Home in the observations published 
in the last volume of the Phil. Trans. 1838, Part 2, appears, by its results at 
the Atheneum at Plymouth, and at Ham, near London, to have given dips ex- 
ceeding the truth by about half a degree. It is probable that a careful examina- 
tion would trace this error to imperfection in the axle; and in such case errors 
of a contrary character would exist when the axle should rest on some other 
points of its circumference, and may have influenced the determinations at 
some of Sir Everard’s foreign stations. By the methods pointed out in this 
report, a table of errors at different dips might be formed for this needle, by 
which its results might be’corrected. This additional trouble would be well 


bestowed in perfecting this extensive series, on which so much pains have 
already been expended. 


MAGNETIC SURVEY OF GREAT BRITAIN. 57 


work in jeweled holes. By means of the “ deflectors ’’ which 
make a part of Mr. Fox’s apparatus, the dip may be deduced 
from readings at various parts of the circle, and there is there- 
fore the same opportunity of discovering errors caused by mag- 
netism of the circle, or by imperfection in the bearings of the 
axle, as the azimuthal and Mayer’s methods furnish in needles 
of the ordinary construction: the jewel-plate itself is also made 
to revolve, so that the resting-places of the axle in the jewels 
may be changed at pleasure. The performance of these needles 
sufficiently indicates the great care bestowed on their workman- 
ship. As the different observations in Table III. include an in- 
terval of eighteen months, they have been rendered more strictly 
comparable by the addition of a column, in which they are re- 
duced to the common epoch of the 1st January, 1838, by ap- 
plying a proportional part of the annual rate of decrease of the 
dip in London at this time, which, from reasons that will be 
_assigned hereafter, is considered to be 2!"4. 


TABLE III. 


Observations of Dip at Westbourne Green in 1837 and 1838, 
with approved Needles. 


Artist. Needle. Observer. Date. Observed Dip. Deceit, 
Robinson... Pil Phillips May 30, 1837 69° 22-5’ 69°21-1/ 
mendes P aceon Saeed 69 17:9 69 16°5 
Gambey Gl Ross. | Aug. 10, 1837 69 20-6 69 19-7 
pabiiem G2, Petter Bo 69 19:8 69 18-9 
Robinson.. Pil Phillips |March 28, 1838 69 19-5 69 20:1 
eerily P?2 anes ees 69 17:0 69 17-6 
Jordan .... Fox June 8, 18388 69 17:0 69 18-0 
Robinson.. | W1. Ross June 16, 1838 69 16-2 69 17:3 
Sanaa W 2. Sertna conte 69 12:9 69 14:0 
phase R4. peste July 6, 1838 69 13-7 69 14:9 
oats R5. aenena eaaee 69 12°8 69 14:0 
aausks R6 Senda July 7, 1838 69 14:0 69 15-2 
Sanna RZ. cee at's t saytse 69 16-4 69 17-6 
debits R4 marece Dec. 4, 1888 69 15:5 69 17-7 
Bavawe R5 Sects naticate 69 12:8 69 15:0 
eed R6 aeaea Dec. 10, 1888 69 15:9 69 18-2 
“oA R7 nase Ate. 69 14-4 69 16:7 
Mean...,... 69 17-2 


The subjoined tables, IV., V., VI., VIT., VIII., exhibit in de- 
tail the azimuthal examinations which have been made of some 
of the instruments employed in the observations contained in this 
report; it has appeared the more desirable to give these tables, 
because the practice of this method is new in this country. 


58 EIGHTH REPORT—1838. 


Table IV. contains observations made at Tortington on the 
17th of October, 1837, with Captain Fitz Roy’s Gambey, and 
its needle No. 2. The dip is here successively deduced from 
the angles of inclination observed in azimuths 90° apart from 
each other. In such case, cot? 6=cot? i+cot? i, 6 being the 
true dip, and 7 and 7’ the angles of inclination in any azimuths 
90° apart. In the first example in the table, 7 is the angle-of 
inclination shown by the needle when the plane of the circle is 
removed 10° from the magnetic meridian ; that is, when it is in 
the direction of N. 10° E., and 8. 10° W; 7 therefore includes, 
and is the mean of observation with the poles direct and re- 
versed, and with the index of the azimuth circle at 10° and 190°; 
d is in like manner a mean of the angles of inclination with the 
poles direct and reversed, when the index of the circle is at 
(10+ 90°=) 100°, and at (100+ 180°=) 280°: here cot? 7+ cot? 
t!= cot? 69° 13/*5 + cot? 86° 15/-2=cot?8; whence 5=68°56"64. 
In the next deduction, the values of 7 and 7! are obtained with 
the index of the azimuth circle at 20° and 200°, (20+ 90°=) 110° 
and 290°, and so forth. 


TasBueE LV. 


Tortington, Oct. 17, 1837, with Captain Fitz Roy’s Gambey, 
Needle 2. Observer, Major Sabine. 


a rt 

3 | Pol 1 Di 3 | Poles |Polesre- Di 

g divect: |weee| Mean. (| aodutea. 5 direct. | versed. | 240+) deauved, 

< < 

T0169 15 16903 Leo vecla 50176 065175 507) Lanonaly 

. ; y o 5 . 

190 |69 07 |69 29 } eo 135 230 |75 53-276 13 }v Gq 
100/86 12 |86 28-7] | g¢ yx.o (Oo | 140 (73 34-2173 49-2) | 79 ng | (089640 
280/8625 |3555 | f 320 (73 44-3173 24:3 

20 |70 04-5169 50 a 60 |79 087/78 48 
200/70 00-2170 16 } 70 027 240 |78 52-8179 16-5 }v9 big 
110 |82 36-282 50°7| | ga a9 | [8964] 15071 34 [71 50-2|1 >) 95.0] POPP 
290 [82 45-5182 23:5 \ 330 |71.39-2/71 19-5 

30/7139 |71162|) .,. 70 |82 31-7/82 14 : 
210|71 26-2171 40-3 } SEGO 250 |S2 18-8|82 36-5 }e2 aaa 
12079 09-7179 26 |. 79 13 | O84 160 |70 05-7/70 22-5] 1 79 g7 68 55°55 
300 |79 205/78 56 } 340 |70 07-5/69 52:5 

40 |73 37-7/73 18:3 80/8611 |85 44 . 
220 |73 23-8173 40-2 bas cae oall 26018556 [86 14-7 } 86 nae 
1307607 |76 23-2} | 76 19.4) [ooo || 170 [69 09-2169 30-5] 1 go 13.0] [Ora 
310 (76 16:5|75 55 | 350 16913 [69 02:3 

0/68 55°5/68 46 hes 56-4| 5856-4 


180 |68 52 |69 12-2 


MAGNETIC SURVEY OF GREAT BRITAIN. 59 


_ The mean of the nine results in the preceding table is 68° 56""1. 
Each angle is a mean of four readings. Total number of read- 
ings, 272. 


Table V. (in two parts) contains observations made by Cap- 
tain Edward Johnson, R.N., F.R.S., and myself, with the same 
circle and needle, in the Regent’s Park, London, on the 15th 
and 16th Nevember, 1837. In this case, the reversal of the 
needle on its supports was made a part of the series, in addition 
to the reversals in the last table; thus the values of 7 and 7?’ are 
each the mean of eight angles instead of four. 


TABLE V,. 
Observations with Capt. Fitz Roy’s Gambey, Regent’s Park, London. 


Observer, Captain Johnson. 1837. 


Poles Direct. Poles Reversed. 


Noy. |Azimuth. Needle, Needle. Means. Dip Deduced. 
Direct. | Reversed.| Direct. | Reversed. 


6 | 69 19-25|69 14:25/69 16°75 69 35:25| 69 21:57] ~ ....| 2° _’ 
15. 1+ 180 | 69 19:75|69 24-25] 69 43:75| 69 28°75] 69 29-13 69 25:25) 69 25-25 


15|70 0 |69 49:5 |69 50 | 70 04-5 | 69 56 ‘ 
195 |69 58 | 70 07-5 |70 15:5 |69 59 | 70 05 } 70 : 

105 | 84 15:5 |84 36 |84 375 |84 285 /84 29-4 | 9, g., | (9 2208 
285 |8428 |8415 | 84 13-5 |84 30-5 | 84 21-7 } 5 


30/72 04 [71 45:5 |71 485 /72 08 |71 565 1 7) so 

210/71 54 |7205 |72 145 |72 00 |72 03-4 f 71 59:95 
120|79.15 |79 345 |79 335 |79 14-5 |79 24-4 1 a9 ong 
300 |79 26 |79 095 |79 06 |79 27 |79 171 ha J 


45 |75 12:5 |74 58-5 |74 57 | 75 16-25) 75 06-1 
225 |75 07 175 16 |75 195/75 03 |75 11-4 
135 | 75 03°5 |75 11 | 75 17°5 |75 06:5 | 75 09-6 bas 05-4 


} 75 08-7 


| 315 [75 05 =|75 005 | 74 525 |75 07 =| 75 01-2 


60|79 29 |7910 |79 13 |79 388 |79 22-5 79 25-3 
240 |79 26 |79 34 + |79 87 |79 15:5 |79 28-1 5 
150} 71 55 |72 04 | 72 125 |71 52-5 | 72 01 71 563 
| 330 | 71 56:5 |71 45 | 71 46:5 |71 58-5 | 71 51-6 } 


75 |84 83:5 /84 215 |84 18 [84 365 |84 27-4 1 2, oa 
255 |8428 |8431 |84 415/84 21 | 84 30-4 
165 |69 565 |70 045 |70 17 |69 57 | 70 03-75 
345 |70 035 |69 51-5 |69 48 | 70 065 | 69 57-4 } a0 O08 


180 | 69 17:5 |69 297 |69 41-5 | 69 07-75| 69 24-11 
0 |69 205 |69 13:5 |69 10 |69 38 |69 205 } 69 so aig Bei Sean 


General Mean. 69 23: 7 


60 EIGHTH REPORT—1838. 


TABLE V. if 


Observations with Captain Fitz Roy’s Gambey, in the Regent’s Park, | 


London. 
Observer, Major Sabine. 1837. Ire : 
Poles Direct. Poles Reversed. : j 
Nov. |Azimuth, Needle. Needle. Means. Dip Deduced 
Direct. 


Reversed.| Direct. | Reversed. 


SS 


° « 
69 24:75 


6 | 69 20-8 | 69 14-5 |69 15-7 |69 35 [69 21-5 1 Go o4rs 
180 |69 17:5 |69 25-2 |69 43 |69 26:3 |69 28-0 } 


SO eg 8 on ie 


15 |}70 03 |69 49 |69 45 |70 05-5 | 69 55-6 70 01-2 
195 |69 595 |70 10 |7019 |69 59 | 70 06-9 } 

105 |84 18 | 84 40-5 |84 38:5 |84 23 | 84 30 84 27 
285 |84 32 | 84 155 |84 16 |84 33 | 84 24-1 } 


aS 


30 |72 02 |71 45 |71 465 |72 11 |71 561 72 
210 |71 54. |72 06 =|72 125 |72 07 +|72 04:9 } 
120 |79 138 | 79 35:5 |79 32-5 |79 23 | 79 26 79 20:8 
300 | 79 245 |79 125 |79 02-5 |79 23) | 79 15°6 } 


| 45 | 75 075 |74 595 |74 585 |75 21-25/75 067 1 75 og.5 
eig.s 225 |75 06 |75 14 |75 15 |75 045 |75 099 | 
135 |75 045 |75 10 |75 20 |75 085 |75 10°75 7 og.on 
315 |75 075 174575 174 54 175 08 |75 ozs ! 


60 |79 24 |79 185 |79 16 |79 42 |79 23-9 79 26-2 
240 |79 24:5 |79 386 | 79 875 |79 16 | 79 285 } 
150 | 71 50-5 | 72 03°5 |72 14:5 |71 54:5 |72 00°75 71 55-75 
330 (71 575 |71 44 «=|71 45) «| 71 565 |71 5075 f 


75 |84 37 | 84 22-5 |84 19-7 | 84 37-5 | 84 29-2 84 303 
255 |84 285 84 32 |84 36 |84 29 | 84 31-4 69 23-08 
165 | 69 55°5 |70 05:5 |70 18 |69 57 |70 04 


345 |70 065 |69 49 |69 50:5 |70 05 | 69 37.75 t igh es 


180 |69 17 |69 33 |69 42:7 |69 09 | 69 25-44 
0 |69 21 |69 13-2 | 69 125 |69 43:5 | 69 29.56 f ad Be IL Be 


General Mean. 69 24-11 


Each of the numbers, both in Captain Johnson’s and Major 
Sabine’s observations, is a mean of the readings of the two ends 
of the needle. In the azimuths 0 and 180° each number is also 
a mean of two distinct observations, between which the needle 
was raised from its supports, and lowered afresh. At all the 
other azimuths one such observation by each of the observers 
was considered sufficient. The total number of readings is 224 
by each observer. 


tke 
2 a 
“ 
. 


? 
4 


MAGNETIC SURVEY OF GREAT BRITAIN. 61 
TaBLe VI. 
Observations with Gambey’s Circle and Needle 2 at Dover; 
: by Major Sabine. 1837. 
Face of Needle to face of Circle. 
Azimuth, Remarks, 
Poles Poles 


Direct. | Reversed. Mean. Dip. 


P 30 and 210 7 su 
120 and 300 4 ; 
2 . hill. above Arch- 
60 and 240) 79 aaa ees 68 52-9| cliff Fort on the 
48:8 


1g || 68 582 |On the side of the 
a) 68 518 2nd November. 


+ Ft tees 


150 and 330) 71 
0 and 180) 68 


i ETL a ale ere RO ee SS eee 68 52-6 


Face of Needle Reversed. 


30 and 210| 71 30-°5| 71 32°5| 71 315 / 

120 and 300| 79 02-2| 78 54:5| 78 58-4 f|08 51°3 |Beneath — Shak- 
60 and 240) 79 145] 79 13 | 79 13-7 1 \eg cog | SPeare S Cliff on 

150 and 330] 75 21:7| 71 27 | 71 24:4 } the 7th November, 
0 and 180| 68 52:7| 68 54-6| 68 53-6 |68 53-6 


NY Co ee eee eosaleecs tarcnape ton eb diaaeseces 68 52-4 


Table VII. contains observations by Professor Phillips, with 
a six-inch circle by Robinson, and its needle 1. The inclination 
of the needle (7) was observed with the circle in different azi- 
muths (@), and the dip computed from the inclination found in 
each azimuth by the formula cot 5 = cot ¢ sec @. 


Peg egg teen 


; TaBLe VII. 
. Observations of the Dip with Mr. Phillips’s Circle and Needle 1. 


~ York, Sept. 13, 1838. Helmsley, Sept. 14, 1838. Malton, Sept. 15, 1838. / 


_|Azimuth. Inclination Dip. Azimuth.| Inclination Dip. Azimuth.| Inclination Dip. 
() z 6 6 z 6 te) Z 6 | 


—_—_—_ —_—————— || — | ___ 


é‘ 4 é 
6| 70 50°6|| 00 | 7o 57-4| fo 57-4]) 00 | Jo 51-7| 70 51-7 
10 | 71 08-2| 70 515|| 10 | 71 14-2| 70 58-0|) 10 | 71 08-1] 70 52 
3-7| 70 49:1|| 20 | 72 01-7| 70 56-0|| 20 | 71 54 | 70 49:3 
30 | 73 16-9| 70 525) 30 | 73 215| 70 57-5|| 30 | 73 15-5| 70 506 
40 | 75 04-6| 70 485|| 40 | 7513 | 70595]| 40.| 75 03 | 70 47 
50 | 77 22:5| 70 47:3|| 50 | 77 31-4| 71 00-0|| 50 | 77 26-1| 70 525 
60 | 80 07:9| 70 49:9|| 60 | $016 | 71 04-0] 60 | 80 05-9| 70 45-4 


. 


Mean Dip...| 70 48°6 Mean Dip...| 70 589 Mean Dip...| 70 49:8 


SS eee eee 


62 EIGHTH REPORT—1838, 


Table VIII. contains observations by Captain James Ross, 
with a six-inch circle by Robinson, and its-needles R. 4. and 
R, 6., at Jordan Hill, in September 1838. The dip is here com- 
puted by the formula, cot °6 = cot *¢ + cot *i'; and in the 
final column the dip observed in the ordinary manner, ¢.e, in 
the azimuths 0 and 180°, is inserted for comparison. . 


TaBie VIII. 
Observations with Robinson’s Needles R. 4. and R. 6., Jordan 
Hill, September 1838. 
Observer, Captain James C. Ross. 
Needle R. 4. 


Poles a. Poles #3. : ’ 
Azimuth. ——_____ | —--—— Dip Azimuth. 
‘\| Needle Needle Needle Needle Means. Deduced. |} 0 & 180° 
Direct. | Reversed.| Direct. | Reversed. 


oO? ° i ‘ ° / ° ° ‘ O° 7 
60 || si ‘46| $1 toa] 81 35) 81 185 }a1 
240 || 81 42| 81 36| 81 3:3| 80 44-5 
150 || 74 81°6| 74 27:8| 74 198] 74 323|1 74 94 Vis 21°6 || 72 22:2 
330 || 74 47-2| 74 29-9| 74 40°8| 74 28 \ 


Needle R. 6. 


45 || 77 10-7| 77 55|77 26 | 77 26 |) ,, 16. 
295 75 58| 77 24 | 77 22:8| 77 13 67 
185 | 77 185/77 5 | 77 25-1] 77 21-2) ,, 19. 
815 | 77: 15°7| 77 28:3] 77 21-7| 77 22-9 } 2 


jr 19°4 72 17°7 


Annual Alteration of the Dip. 


The observations of dip included in this report, extend over 
an interval of four years and upwards. ‘To reduce these to a 
common epoch, we require to know the amount of the change 
which the dip undergoes from year to year. In the Reports on 
the Magnetic Observations in Ireland and Scotland, an annual 
decrease of three minutes was provisionally assumed ; but we 
must now endeavour to assign the amount with somewhat 
greater precision. 

In the 21st volume of the Annalen der Physik, M. Hansteen 
has assembled all the most trustworthy observations of the dip 
in London, Paris, Berlin, and Geneva during the present cen- 
tury, and the latter part of the last; and has computed from 
them the most probable amount of the annual decrease of the 
dip at each of those stations, corresponding to every tenth year, 
from 1780 to 1830. As the results of this investigation have 
not been published, I believe, in this country, I have subjoined 
a table in which they are exhibited. 


~ Y 
- we 
= 
<4 


ce" 


MAGNETIC SURVEY OF GREAT BRITAIN, 63 


TaBLeE IX, 
Annual Decrease of Dip. 


Year. Paris. | London.| Berlin. | Geneva. |} Mean. 


The differences which appear in the progression and rate of 
the annual decrease at the four stations in this table, are proba- 
bly attributable in far greater proportion to incidental errors in 
the observations, than to the actual existence of such differences. 
We may consequently regard the final column, or the mean of 
the results at the four stations, as affording, in all probability, 
a more satisfactory conclusion in regard to the rate of change at 
any one of the stations than is drawn from the observations at 
that station only. 

We may proceed to examine how far this rate of decrease cor- 
responds with the most recent observations made in Britain. In 

_ August 1821, I made a series of more than usually careful ob- 
servations on the amount of the dip in the Regent’s Park in 
London; employing for that purpose a needle on Mayer’s 
pepe, with weights of different magnitudes to obviate the 
iability to any constant instrumental error, and continuing the 
observations during several days in order that the general re- 
sult might approximate the more nearly to the true mean dip 
at the period. These observations were published in the Phil. 
Trans. for 1822, Art. I.; their final result being a dip of 70° 

02"9, corresponding to the middle of the month of August 
1821. To compare with this, we have the observations made 
‘in London, at different times and in different localities, by 
the contributors to this report. It is proper that we should 
employ for the present purpose only those observations which 
‘give entirely independent determinations ; viz. those only which 
are complete in all the requisite positions of the needle and 
circle, including the reversal of the poles, and which need no 
correction for instrumental defects. Of such observations we 
have those at Westbourne Green, already given in Table III. ; 
those in the Regent’s Park, contained in Table V.; an obser- 
vation by Mr, Fox, in May 1838, in a field west of Maiden 


64 EIGHTH REPORT—1838. 


Lane, and one of mine, on the 13th of October, 1838, in the 
gardens of the Palace at Kew. ‘These are collected in the fol- 
lowing table. ‘ 


TABLE X. 


Observations of the Dip in London in 1837 and 1838, 
with approved Needles. : 


Date. Observer. Dip observed. Place of Observation. 
1837. at; 
May:30:) vecesasssacuens Phillips 69 20:2 Westbourne Green. 
aa A enacectaner eas Ross 69 20:2 | Westbourne Green. 
ING Li Udine soncses Johnson & Sabine 69 23-9 * Regent’s Park. 
1838. , 
March: 28), ...ds..0s006 Phillips 69 18:2 | Westbourne Green. 
Wav i2e~ Savsanantenes os Fox 69 19-0 Maiden Lane. 
AG Os) aravanascscens Fox 69 17:0 Westbourne Green. 
WUDCIEG: deaccesacvoosse Ross 69 14:5 Westbourne Green. 
uakyy Giysfiases cece ake Ross 69 13°3 Westbourne Green. 
UUs fi doaseete eG cocneta Ross 69 15-2 | Westbourne Green. 
OC oliateatesdecrs Spree Sabine 69 165 Kew Gardens. 
IDeCraNsc. cctcssecccnere Ross 69 14:1 Westbourne Green, 
Dect lO yicecdrenst cooee Ross 69 15-2 Westbourne Green. 
corresponding to the beginnin iets 
Mean { of May 1838. 8 8 69 17:3 


We have therefore 70° 02’-9 in August 1821, and 69°17°3 in 
May 1838; ora diminution of 45/6 in 16°7 years, equivalent — 
to a mean annual decrease of 2!73, corresponding to the middle 
of the interval, or to the beginning of the year 1830. The 


* This is the mean of fourteen results, extremely accordant with each other, 
obtained in different azimuths; (see Table V.). It will be remarked that it is 
decidedly the highest of the results from which the mean dip in London has 
been derived. ‘The observations with the same instrument at Kew, as well as 
every comparison between this and other instruments, give reason to believe 
that the high dip in the Regent’s Park, in November 1837, is not attributable 
to any instrumental error. It may then have arisen either from the dip on 
those days being actually greater by three or four minutes than its general 
average, or from some local disturbing influence. The locality is the same in 
which the observations in 1821 were made, and the result in question may 
on that account appear more strictly comparable with them; but though 
the locality is the same, it is not one in which we can feel confident that no 
change may have occurred in regard to magnetic influence. The Regent's Park 
is certainly not so eligible a situation now for magnetic experiments as it was 
in 1821. These considerations have induced me to derive the London Dip in 
1838 for the purpose in the text, from the mean of the observations and local- 
ities in Table X, rather than from those in the Regent’s Park alone; and not 
to give to the latter result that additional weight in comparison with the . 


others to which it would seem entitled as derived from observations in so many 
azimuths. 


rt 


MAGNETIC SURVEY OF GREAT BRITAIN. 65 


mean rate for the same year in M. Hansteen’s table is 2/93, 
which must be regarded as a satisfactory accordance, the dif- 
ference being less than exists between the rate for that year at 
any one of the siations in M. Hansteen’s table, and the mean 
of the four stations. We may infer from the accordance, there- 
fore, that both these numbers, 293 and 2°73, are extremely 
near the truth; and I have employed that which results from 
our own observations, namely, 2/*73 corresponding to 1830. 
Following the progression in M. Hansteen’s table, the rate of 
decrease would become 2''4 in 1836, which is the middle pe- 
riod of the observations contained in this report. In the re- 
ductions to a common epoch, 2!:4 has consequently been em- 
ployed as the mean annual decrease of the dip in the British 
Islands between 1834 and 1838. In the absence of any certain 
knowledge in regard to the unequal distribution of the yearly 
decrease in the different months of the year, I have regarded it 
as taking place in the uniform proportion of 0-2 per month. 
In a recent communication to the Royal Irish Academy, Mr. 
Lioyd has stated the result of thirty-nine observations of the dip 
in Dublin between October 1833 and August 1836, which, com- 
bined by the method of least squares, give 2°38 for the most 
probable rate of the annual diminution of the dip in Dublin 
during that period. This result, though drawn from so limited 


_ a period, is in remarkable accordance with the deduction from 


the observations in London, and furnishes a strong presumption 


_ that the rate thus found is applicable both to England and Ire- 


[4 


land. In regard to Scotland, no observations have as yet been 


_ made, I believe, with this particular object. The general 


~~ 


Pas 


aspect of the observations in Scotland, at different dates, con- 


tained in this report, would certainly indicate a less annual 
_ change than has been deduced from the observations in England 
~ and Ireland; and in every instance in Scotland where obser- 


gar’ 
_yations have been made at the same station and at different 
periods, either by the same or different observers, the evidence 


is of the same nature,—the results would be brought into better 
1) 


accord if a smaller rate of decrease were adopted. In the case 


_ of the Shetland Islands, the dip observed by Captain Ross at 
| Lerwick in August 1838, 73° 45’, compared with that observed 
_ by Sir Edward Parry and myself in June and November 1818, 


> sas & 


5 
“| diminution of 1'"85, corresponding to the mean epoch of 1828. 
_ The observations of 1818 and of 1838 were made in the same 


74° 22', makes a decrease of 37! in twenty years, or a yearl 
; ’ y years, yearly 


garden. The identity of the spot,—the length of the interval,— 


_ and the repetition of the observations on different days on both 


occasions,—all give weight to this comparison ; and strengthen 
VOL. VII. 1838. F 


66 HIGHTH REPORT—1838. 


the inference, that the rate of annual decrease is less in Scot- 
land than in England. Still, in the absence of more positive 
data, I have not chosen to make any assuthption; and have 
employed the one rate for the whole of the British Islands. 
The general result in Scotland, 7. e. the mass of observations 
taken collectively, is independent of the amount of this re- 
duction, the sum of the + and — reductions to the mean epoch 
of the 1st of January, 1837, being very nearly the same: the. 
effect of a less rate of diminution than that adopted would be 
to increase the dips deduced from the observations in 1836, and 
to decrease those deduced from the observations in 1837 and 
1838; and thus to give a rather more consistent aspect to the 
whole, without sensibly altering the resulting isoclinal lines. 
No correction has been applied for the different hours of the 
day at which the several observations were made; but the hour 
is in almost all instances recorded, Professor Phillips had 
devoted several days of observation to the investigation of the 
regular horary variations of the dip, and had obtained results 
remarkably consistent, considering that they were derived from 
observations with the ordinary dipping needle*; but the recent 
invention of instruments specially adapted to this object, renders 
it probable that the phenomena of the periodical changes will be 
shortly determined with an accuracy hitherto unattainable: in 
the mean time, it has appeared preferable to apply no correc- 
tion on this account. It may be proper to remind the reader, 
that the most perfect correction in this respect would still leave 
unremedied the influence of the irregular fluctuations, which 
there is great reason to believe frequently exceed in amount, and 
occasionally counteract the ordinary periodical movements. 


I proceed now to give in detail the observations which com- 
prise the first division of this report; namely, those of the Dip 
in England, Scotland, and Ireland, It will be convenient to 
separate these into three sections, commencing with those of 
England; and it may here be remarked generally, that all the 
latitudes and longitudes in this Report are taken from the maps 
published by the Society for Diffusing Useful Knowledge. The 
longitudes east of Greenwich are distinguished by the negative 
sign prefixed. 


* Mr. Phillips’s observations at St. Clairs and York, in the summer of 1837, 
from 7 a.m. to 11 p.m., appear to indicate a morning maximum of dip at 9 or 
10 a.m., an evening minimum about 8, with a difference of above 5 minutes, 
the mean dip recurring about 3 p.m., and the line passing through the three 
points nearly parabolic, 


MAGNETIC SURVEY OF GREAT BRITAIN, 


Srotrion I,.—ENGLAND. 


67 


Mr. Fox’s observations.—I have arranged in the following 
table the observations of the dip in England with which I have 
been furnished by Mr. Fox, and have added thereto the columns 
containing the latitudes and longitudes, and the dips reduced 
to the mean epoch of the lst January, 1837. The results in 
1835 were obtained with a six-inch apparatus; those in 1837 
with a seven-inch, and those in 1838 with a four-inch appa- 
ratus; all the instruments being those of Mr, Fox’s construc- 
tion, and made by Mr. Thomas Jordan of Falmouth. 


TABLE XI, 
Mr. Fox’s Observations of the Dip in England. 
‘ Dip de- 
Station, Date. Hour, Lat, | Long. | psotea. | Tyan? | Observation. 
1837. 
é 
v[Sept. 1, 35 | 5am. |53 19] 4 37) 71 04 [71 00-8|Hote1 Garcen. 
Sept. 1, 35 |10 a.m. 53 14| 4 06) 71 02 |7058-8/Hotel Garden. 
Sept. 1, 35 3 PM 53 09| 4 14| 70 58 |70 54-8|Hotel Garden. 
Sept. 1, +35 65 rm. 53 07| 4 03} 70 57 |70.53-8|Foot of Snowdon. 
Sept. 3, -35 a A.M. 53 06| 3 53) 70 48 |70 44-8)Hotel Garden, 
3 A.M. ; 
Sept. 5, 35 |103 a.m. 52 07| 219} 70 11 |70.07-8|Mean of 3 Stations. 
5 vm. 
sg i 95 a.m. . ; 
ept. 8, °35 res 51 55| 2 35) 70 00 |69 56-8)Hotel Garden. 
..|Sept. 1], 35 2 pM. 51 40| 3 46] 69 57 |69 53-9)Glenvellya Cottage, 
../Sept. 9, °35 8 a.m. 51 38] 2 46} 69 48 |69 44-8/Hotel Garden. 
Aug. 25,°37 {ll a.m. 55 07) 1 53) 71 17 (7118-6 
..|/Sept. 7, °37 4PM. 54 40} 3 09) 71 15 {71 16-6)The Summit. 
.|Sept. 7, 37 | 8 a.m. 54 32] 3 09) 71 14 |71 15-G|Near the Lake. 
| Aug. 19, -37 75 AM. 54 43| 2 00) 71 14 (7115-5 
seree. (Dept. 9, *37 83 a.m. 54 27} 3 Ol] 71 13 |71 14-6\Benind the Inn. 
Aug.21, 37 73 aM. 54 32} 1 33) 71 07 |71 08-5)Polham Hill. 
Sept. 12,°37  |1lZ am. 53 54} 2 47| 70 59 |71 00-7\Inn Garden, 
..., Aug, 14, 37 lp, 54 08| 1 34 70 56 |7057°5 
Sept. 12,:37 | 4 p.m. 53 39| 2 50! 70 45 |7046-7 
Sept. 23, 37 | 8 a.m. 53 25) 2 55) 70 44 |7045-7/At the Dingle. 
Sept.19, -37 03 p.m. 53 25| 2 58) 70 39 |70 40-7|Botanic Garden. 
JAug. 9, 37 {10 a.m. 53 08| 1 32} 70 19 |70 20:5|Bath Hotel Garden, 
May 22, - Mt. apaieeae el es 
Bandon: «.::... pe 3 8 ty Pk | Sa gale o 3] {0012} leo.an-al { Near Mites Lane 
{Tooting .........,Junel4, -38 | 8 a.m 51 26} 0 10) 69 14:5/6917 |The Grove. 
Falmouth.........\July 31, -38 6 P.M, 50 09} 5 06) 69 13°5|69 17-3\mr. Fox’s Garden, 
astwick Park |June 16, -°38 8i am. 5117) O19) 69 08 |6911:5 
astbourne...... June20, 38 | 3pm. 50 47|—0O 16} 68 45 |68 48-5 a eae Gis 
|Combe-House . |July 2, 38 | 82 a.m. 51 31| 2 34] 69 32 \6935-6) "Te 
it. Mary’s, Scilly| Aug.31, -38 8am. 49 55| 617) 69 26 |6930 
_|Trescow, Scilly |Aug.31, 38 l pM. 49 57| 6 18} 69 27 |6931 
F2 


68 EIGHTH REPORT—1838. 


We have in this table the dip observed at twenty-nine sta- 
tions, of which the central geographical position is 52° 45! N. 
and 2° 49' W. If we desire to express the general result of 
this series of observations, as to the position of the isoclinal 
lines, their mean direction, and their mean distance apart in 
the district of country which the observations comprise, in the 
manner proposed by Mr. Lloyd in the discussion of the Irish 
Magnetic lines (British Association Reports, vol. iv. pages 
151—156) ; and if we call 8 the dip at the central posi- 
tion; w the angle which the isoclinal line, passing through the 
central position, makes with the meridian; ra co-efficient de- 
termining the rate of increase of the dip in the normal direction ; 
aand b co-ordinates of distance in longitude and latitude of 
the several stations from the central position, expressed in geo- 
graphical miles: and if we make r cos w=w, and r sinu=y ;— 
we may proceed to form equations of condition of the form de- 
scribed in the report on the magnetical observations in Scot- 
land (British Association Reports, vol. v. pages 4 and 5), and 
to combine them by the method of least squares. It is unne- 
cessary to encumber this report with the details of calculation ; 
and it is sufficient to state, that from the three final equations 
we obtain v= +°2633; y=—'5154; w= —62°'41 (the direc- 
tion being from N. 62°'41 E. to S. 62°'41 W.); r=0'580, 
being the rate of increase of dip in each geographical mile mea- 
sured in the direction perpendicular to the isoclinal line; and . 
5=70° '22°9 the dip at the central position at the mean epoch 
of the observations, namely, January 1, 1837. 


Mr. Lloyd’s Observations.—These observations were made 
with a 4 inch circle by Robinson, and two needles, designated 
as L 3 and L 4, employed also for determinations of the inten- 
sity. These needles consequently had not their poles reversed ; 
and the dips observed with them require corrections to produce 
the true dip. These Corrections have been ascertained by Mr. 
Lloyd, as stated in a subsequent part of this Report, to be as 
follows : 

Needle L 3. + 573 
Needle L 4. +13!"4 


These corrections have been applied in the following table, in 
the column entitled Corrected Dip. 


TaBLE XII. 


1836, Hour, Needle. eiatheg Sencctet Place of Observation. 
fo} 4 ° ‘ 
London ...| Apr. 19.| 1 pm.| L 3 | 69 25-0) 69 30:3 |Westbourne Green. 
Apr. 19,| 1 28 p.mw.| L 4 | 69 07-8|69 21-2 
Apr. 21.| 2 37 pw.| L 4 | 69 138/69 27-2 
Apr. 21.) 2 58 p.mu.| L 3 | 69 21:3/69 26-6 
Shrewsbury} Apr. 25.| 2 45 p.m.| L 4 | 70 05:1|70 18:5 
310 rm.| L 3 | 70 31-4] 70 36:7 
Holyhead .| Apr. 27.|11 15 a.m.| L 4 | 70 556/71 09 |Rocky Height near 
11 304a.0.| L 3 | 71 03:0/71 08:3 | the Town. 
040 pm.| L 4 | 70 53-4|71 06-8 
1 7 vpm.| L 38 | 71 04:0/71 09:3 
1 20 pmu.] L 3 | 71 047/71 10 
Birkenhead] Aug.8| 9 Oa.m.| L 4 | 70 36-2/70 49-6 | Garden of the Hotel. 
i 9 35 a.m.| L 3 | 70 43-6|70 48-9 
10 Oa} L 3 | 70 48-0] 70 48-3 
10 20 a.m.| I. 4 | 70 36-2|70 49-6 
Shrewsbury] Aug. 9 |ll 15 a.u.| L 4 | 70 17-1|70 30:5 | Fieldsnearthe River. 
11 404a.m.| L 3 | 70 22-1|70 27-4 
0 7em. | L 3 | 70 194/70 24-7 
0 20 em. | L 4 | 10 14:6] 70 28 
Hereford...) Aug. 10/10 50 a.m.| L 4 | 69 52:0|70 05-4 | In a Plantation one 
11 204.m.| L 3 | 70 02-6] 70 07-9 mile from the 
11 45 a.m.| L 4 | 69 53-2|70 06-6 Town. 
0 5em.| L 3 | 70 03:2}70 08:5 
Chepstow ..| Aug. 12 |11 40 a.m.| L 4 | 69 32:6|69 46 | Near the Castle. 
010 rm. | L 3° | 69 44:5 | 69 49-8 
Salisbury...) Aug. 13 |10 45 a.m.| L 4 | 69 09-0| 69 22-4 | Field near the Town. 
11 10a.m.| L 3 | 69 18-5] 69 23:8 
Ryde ......)Aug. 15 |11 30 a..| L 4 | 68 57-1/69 10-5 | Near the Sea. 
0 0 L 3 | 69 01:6|69 06-9 |3 of a mile East of| 
Aug. 16] 0 20r.m.| L 4 | 68 405/68 53:9 | the Town. 
0 45 e.m.| L 3 | 68 53°8|68 59-1 
Clifton...... Aug. 29 |11 15 a.w.| L 4 | 69 27:0|69 40:4 | Durdon Downs. 
11 40 a.0.| L 3 | 69 39°8/69 45-1 
0 5em.| L 4 | 69 308/69 44:2 
0 30er.m.| L 3 | 69 35:-4/68 40-7 
Ryde ...... Sept. 24 |11 45 a.m.| L 4 | 68 49-4/69 02:8 
0 15 e.m. | L 3 | 68 505) 68 55:8 
0 40 rm. | L 4 | 68 47:8|69 01:2 
1 10pm. | L 8 | 68 55-4|69 00:7 
Brighton...|Sept. 27 |11 15 a.m.| L 3 | 68 43°8|68 49-1 | Downs N.E. of the 
11 40 a.m.| L 4 | 68 36:9|68 50:3 Town. 
‘ 0 0 L 3 | 68 44:0| 68 49:3 
Ys 0 30r.m.| L 4 | 68 368/68 50-2 
v London ...| Oct. 4 | 0 45 e...| L 3 | 69 17-4|69 22-7 
€ 1 20pm.| L 4 | 69 02-6|69 16 
a 1 40 vm. | L 3 | 69 12:0|69 17:3 
2 Orm.| L 4 | 69 06:8) 69 20-2 
Cambridge | Oct.8 | 0 20 yr... | L 3 | 69 37-0|69 42:3 | Grounds of Trinity 
0 407m. |} L 4 | 69 31:0) 69 44-4 College. 
110rm.} L 3 | 69 30:5| 69 35°8 
1 35 pm. | L 4 | 69 80-1/69 43°5 
Lynn ...... Oct. 10| 0 55 e.m. | L 3 | 69 51:0) 69 56:3 | Pleasure-ground 
1 25r.m.| L 4 | 69 38-6] 69 52 near the Town. 
2 Orm.| L 3 | 69 48:5) 69 53-8 
2 20epm.| L 4 | 69 37:5|69 50-9 
Matlock ...) Oct.12|} 0 15 r.m.| L 3 | 70 27:2|70 32:5 | Field N.ofthe Town. 
0 25rm.| L 3 | 70 255/70 30:8 
0 35em.| L 4 | 70 13:-4/70 26:8 
0 50 rm. | L 4 | 70 184/70 26:8 
Manchester] Oct. 14/10 50 a.r.| L 3 | 70 43:5|70 48:8 | Field near the Town. 
L 3 | 70 44:2|70 49:5 
L 1 | 70 344/70 47°8 
L4 70 44:8 


70 EIGHTH REPORT—1838. 


Table XII. contains the latitudes and longitudes of Mr. 
Lloyd’s stations, and the mean dip at each station: the number 
of distinct comparisons are, at London 2, Shrewsbury 2, 
Ryde 2; at each of the other places, 1: in the subsequent 
calculation, these numbers are taken as the weights. 


TaBLeE XII. 

Station. Lat. | Long. Dip. Station. Lat. Long. Dip. 

fe) 4 Of, ie) Us OT ie] ud 
Holyhead... |53 19] 4 37] 71 08-5 || Chepstow 51 38] 2 41) 69 47-9 
Birkenhead. |53 24] 3 00) 70 49-1]] Clifton......... 51 27] 2 36) 69 42-6 
Manchester. |53 28} 2 14) 70 47-7 || Cambridge ... |52 13|—0 07] 69 415 
Matlock ... |53 08] 1 35) 70 29-2! Salisbury...... 51 04} 1 47} 69 23-1 
Shrewsbury. |52 42] 2 46] 70 27-6|| London ...... 51 32] 0 11) 69 22-7 
Hereford ... |52 04] 2 44] 70 07-1]! Ryde ......... 50 44] 1 10) 69 01:3 
Hiyiiticesesss +: 52 45 |—0 25] 69 53-2]! Brighton...... 50 50} 0 08] 68 49-7 


If we combine these fourteen results by the method of least 
squares, we obtain the following values: 2 = + -2899 3 
y=—'5753; u=—63° 15'; r=0°644; and S=69° 54! at the 
mean geographical position, of which the latitude is 52° 4!, and 
the longitude 1° 43’ W. 


Professor Phillips’s Observations.—These were made with a 
six-inch circle and two needles, by Robinson. At some of the 
stations marked +}, the reversal of the poles was intentionally 
omitted, from a desire to determine small local differences, under 
circumstances as similar as possible, the needles being very 
nearly equilibrated. The table shows which of the observations 
were thus incomplete ; and the comparison of the results at the 
other stations, before and after the reversal of the poles, shows 
the probable small limit of error which may have been involved 
by the omission. With the poles direct, and also with the poles 
reversed, the mean of four positions was taken, being eight in all ; 
the needle was always inverted on its supports, as well as the 
circle turned in azimuth: four readings of each end of the 
needle were generally taken in each position. 


MAGNETIC SURVEY OF GREAT BRITAIN. 71 


TaBLeE XIII. 
Professor Phillips’s Observations of the Dip. 


ee el ea 


Fa Poles, 
Station. Date. | Hour. E #4 iret Mean. | Mean Dip. Cena 
1837. fe) ‘ Sime 6 
London........ May 30 | 2 v.m.| 1 |e 69 22.9 
B 69 221 [69 295 |). , 
2 |e 69 16°6 Li 20:2 |Westbourne 
B 69 191 |69 17-8 Green. 
Doncaster...) June 2 | 6$r.m.] 1 | a 70 cas “a 25°6 
2 |a 70 27°6 |70 27-6 
13 |7 acs] 1 |e 70'BeS |70 343 [670 301 | Garden of the 
2 |« 70 331 |70 33-1 pen anee 
| York.............) — 3 | 23 p.m] 1 |@ 70 486 nus 
B 70 47:3 |70 47-9 1] 
4 2 |e 70 521 
| B 70 45:3 |70 48-7 
| 7 vM.| 1 |e 70. 48-4 
B 70 44:5 |70 46-4 
2 \a 70 45°3 
B 70 45:3 |70 45:3 
— 5/9 am] 1 [oe 70 503 
B 70 51°6 |70 50:9 
2 |\a 70 507 $70 48-6 |Stone in Pro- 
B 70 51-9 |70 51:3 fessor Phil- 
11 a.m.| 1 |e 70 51-2 lips’s garden, 
B 70 50-5 |70 50:8 and stone in 
2 \2 70 51 the grounds 
B 7O 51-5 |70 51:2 of the Philo- 
: 7ipvm.| 1 |2 70 45-1 sophical So- 
B70 46 {70 455 ciety. 
2 \a@ 70 47-5 
B70 49 |70 48:2 |J 
Thirsk.........) — 6|3 p.u.| 1 |2 71 00 
: B 70 59-1 |70 59°5 
| 2} 71 002 70 59:2. |Garden of the 
: B 70 57'5 |\70 58-8 Fleece Inn. 
Osmotherley..| — 6|8 p.m.J 1|# 71 16 
a. B71 23 \71 1:9 
: ; " 2\271 57 71 3:2 |Garden of the 
-__ |Hambleton B71 38 \71 45 Inn. 
| Lit ae | — 7/9 aml 1 |2 71 36 , 
B71 74 \71 5:5 
2/e@71 21 71 40 |Top of the 
B71 381 (\71 26 mountain, 
Whitby........] — 9 | 7Za.m| 1 |% 70 59-4 
B 70 57-4 |70 58-4 ; 
2 \2 70 567 70 57-9 |In Mr. Rip- 
B 70 57:9 |70 57:3 ley’s garden. 
Flamborough.| — 11] 8 p.m.| 1 |% 70 33:8 
¥ B 70 40:7 |70 37:2 
2 | 70 36 70 36:9 |Garden of the 
B70 37) =|70 36:5 Seabird’sInn 
Scarborough..| — 13/1 p.u.| 1 |% 70 40-4 
B 70 42:5 |70 41-4 
2 \a 70 423 70 41:9 |In Dr. Mur- 
B 70 41:9 |70 42-1 ray’s garden. 


OOOO 


72 EIGHTH REPORT—1838. 


3 3 Poles. : 1 
Station. Date. Hour. E A sirect, Mean. Mean Dip. Peta 
1837. Sia 7 
WOK nedeyensas June 14/114 a.m. a 70 47-4 
— 14/1lda.m.| 1 | 8 70 47:5 | 70 47-4 |) 
2 |a 70 47°5 
B 70 48-6 |70 48:0 
— 15/4 pm.| 1 |e 70 461 
6 70 45:2 | 70 45-6 aS 4 
2 \a 70 46°5 70 46:5 |Stone in Pro- 
B 70 49-3 | 70 47:9 fessor Phil- 
8 pm.| 1 |e 70 44:9 lips’s garden, 
B70 44 |70 44-4 and stone in 
2 |e 70 415 the grounds 
B70 49 |70 45:2 of the Philo- 
Sheffield.......] — 17) 7 p.m.) 1 | 70 27:5 sophical So- 
B 70 31:3 |70 29-4 ciety. 
2\@ 70 27:2 70 29°6 |Botanic Gar- 
B 70 32°6 |70 29:9 den, 
Birmingham..| July 3 | 25 rp.) 1 |% 70 9:5 
B70 91)70 93 
2\)}«270 77 
B 70 13-5 |70 106 
— 8/| 6iem) 1 |e 70 45 70 07:2 |Mr, Wreford’s 
B70 66|70 55 garden at ¥ 
2)e70 1:5 Edgbaston. ’ 
B70 56)|70 35 |J | 
St. Clairs near) — 19} 83a.m.| 1 |@ 68 59-1 
Ryde. B 68 58-3 | 68 58-7 
2 |e 68 55:3 
6 69 0-7 |68 58 
— 20/11 am} 1 |e 69 1:2 
B69 12/69 1:2 
2 | a 68 56°8 
B69 37 |69 02 
— 21} 21 ym.) 1 | @ 68 59-7 69 1-2 |Inthe garden. 
: B 68 55°7 | 68 57-7 
2 | a 68 588 
B 68 59°5 | 68 59-1 
— 22) Stam) 1} 69 66 
B69 97 |}69 81 
2\)269 35 
669 9:9 |69 67 |) 
POLK ceorcess es Aug.1|7 a.m.| 1 | 70 48:3 
B 70 53-6 |70 50:9 
2 \« 70 325 
B71 53170 48:9 
tam, 1 | a 70 535 
B 70 54-5 |70 54 
2|a 70 35 
B71 71 |70 51:0 
3 p.m.) 1 |e 70 52:3 70 51:1 |Stone in Pro- 
B 70 51:7 |70 52 fessor Phil- 
2 \a 70 33:2 lips’s garden, 
B71 76 |70 50-4 and stone in 
— 3| 7sam) 1 |e 70 49:1 the grounds 
B 70 53:2 |70 51-1 of the Philo- 
2|a 70 49:7 sophical So- 
B 70 51:1 | 70 50-4 ciety. 


® Needle 2 was subjected to an alteration by Robinson, after the observations of 


MAGNETIC SURVEY OF GREAT BRITAIN. 73 


o 
| Poles. : 
Station. Date. Hour. 3 Ee ee Mean. | Mean Dip. Gites. 
1837. tks wpa tea 
Calderstone...| Aug. 12/10$ a.m.) 1 | @ 70 44°6 
B70 45:6 |70 45-1 17 
2 |\a 70 42-6 
B70 495 |70 460|| , , 
Ii pM,.| 1 | 70 37°6 70 43:5 |Inthegrounds 
B 70 42-2 |70 39:9 of J. N. Wal- 
2\a 70 44 ker, Esq. 
Douglas, Isle B 70 41-6 |70 42:8 
of Man...... — 17/3 em.) 1 |a@ 71 205 
B 71 22:7 |71 21°6 |4 
2\a@ 71 23 4 
copenaey RR li 22:2 Castle Mona 
Castleton ...| — 18] 824a.m.| 1|@ 71 23:3 |71 23:3 tn eee: 
2)6 71 21:8 |71 21:8 la 22°55 |In a field ad- 
'+Peel Town..| — 18) 2 pm.) 1/6 71 22°6 |71 22-6 joining the 
216 71 24-7 |71 24-7 Inn yard. 
3ipm.| 1/6 7124 |71 24 71 24:0 |Near the Inn 
2/6 71 246 |71 246 and on the 
Birkenhead..| — 26} 1 r.m.| 1 | 6 70 40-6 |70 40°6 Castle Hill. 
2 |B 70 39:8 |70 39:8 
1 pm.| 1 | « 70 388 |70 38:8 | ¢70 39:4 [Inn garden. 
2\a 70 386 |70 38°6 
Coed Dhu.,...| Sept. 20) Noon | 1 | a 70 40:7 
B 70 40-2 |70 40-4 
# \eotOra ls 70 40:9 |Grounds of J. 
B70 41:5 |70 41-4 Taylor, Es 
+Bowness .... — 25/9 a.m.| 1|@ 71 18-9 |71 18-9 Te 
2168 71 17-9 |71 17:9 tn 184 |Ullocks Inn, 
'-Coniston ...) — 25) 1 vp.) 1/6 71 19:1 |71 19-1 the terrace. 
2 |B 71 20 71 20 hn 19:5 |Field near the 
'+Patterdale....) — 27) li rm.) 1 |@ 71 19:9 |71 19°9 Inn garden. 
2 |B 71 19:4 |71 19°4 ha 19-6 |Inn garden, 
+Penrith......) — 28)103.4.m.| 1 | 6 71 23-7 |71 23:7 
2|6 71 23:2 |71 23°2 kn 234 |In the Castle. 
Carlisle......) — 29/103 a.m.) 1 | 6 71 27°5 |71 27:5 
216 71 29°5 |71 29°5 kn 28:5 |In the Castle. 
Newcastle.... — 30) 7 am.| 1 |6 71 18:2 |71 18-2 
2\67118 |71 18 hn 18:1 |Fields west o: 
1838. the town. 
London,.......| Mar.28| 43 p.m.) 1 | 2 69 20-4 
5 B 69 18°6 |69 19°5 
a 69 16-1 
69 18:2 | Westbourne 
B 69 17:9 |69 17 } Green 


Table XIV. contains the latitudes and longitudes of Mr. Phil- 
lips’s stations, and the mean dip at each station reduced to the 
middle period of his observations, viz. the 1st of August, 1837. 


the 22nd July, one of its arms having been originally longer than the other, so as 
sometimes to touch the circle. By shortening this arm the centre of gravity was 
slightly displaced, as is shown by the observation of Aug. 1. This was remedied 
by Mr, Phillips, the same evening, by grinding the other arm. 


74 BIGHTH REPORT—1838. 


TABLE XIV. >" 


Station, Lat. | Long. 1 Ang Ree), Station. Lat. | Long. |; aun Rb, 
4 ‘ ° 4 ‘ ° 

Carlisle.......010-.| 54.54| 2 54 | 71 285 54 39| 6 37 | 70 57-9 
Peel Town.......|54 13] 4 43 | 71 24 1 05 | 70 48-4 
Penrith ........... 54 40] 2 45 | 71 234 2 53 | 70 43-5 
Castleton......... 54 04] 4 40 | 71 22°5 0 24 | 70 418 
Douglas........+. 54 10] 4 27 | 71 222 |\Coed Dhu........ 53 11) 3 12 | 70 40-9 
Patterdale........ 54 32| 2 56 | 71 19:6 ||Birkenhead...... 53 24) 3 00 | 70 39-4 
Coniston......... 54 22} 3 05 | 71 19:5 ||Flamborough....| 54 08) 0 08 | 70 36-9 
Bowness ...ses00s 54 22| 2 55 | 71 18:4 || Doncaster ........ 53 31) 1 07 | 70 30-2 
Newcastle........ 54 58) 1 38 | 71 18:1 ||Sheffield ......... 53 22! 1 31 | 70 29°6 
Hambleton End,| 54 20| 1 15 | 71 04 ||Birmingham. ...| 52 28) 1 53 | 70 07-2 
Osmotherly..,...) 54 22} 1 18 | 71 03-2 ||London........... 51 32] 0 11 | 69 19-2 
Phirskevsisiisis.. 54 14] 1 21 | 70 59-2 ||St. Clairs......... 50 44) 1 08 | 69 O12 


If we combine these twenty-four results by the method of 
least squares, we obtain the following values: x= + *2658 
y=—'5270; w=—63° 14!; r=0'590; and 8 =70° 50"1 on 
the 1st of August, 1837, at the mean geographical position of 
which the Latitude is 53° 49', and the Longitude 2° 08'. 


Captain Ross’s Ohservations.—In this extensive series no less 
than fifteen needles were employed. Those designated as RL 1 
and RL 2, J, C, C2, and C3, were four-inch needles made by 
Robinson, and used in a circle made by Jones; the remainder 
RL3,RL4,R3, R4,R5,R6, R7, W 1, and W 2, were six- 
inch needles, also by Robinson, and used in a circle by the same 
artist: R4, R5, R6,R7, W 1, and W 2, were fitted with revol- 
ving axles, and were found on trial to give accordant dips in 
different positions of the axle: each observation with them re- 
corded in the following tables is a mean of the usual eight 
positions. For these needles, consequently, no corrections 
are applied, and it will be seen by the observations at West- 
bourne Green in June, July, and December, 1838, that all 
these needles gave very nearly the same dip when used under 
like circumstances of time and place. Their mean result at 
Westbourne Green has been employed by Captain Ross as a 
standard to furnish corrections for the other needles which he 
had employed previously, and on which he could not rely with 
equal confidence. Of these, RL1, R L2,R L3, and RL4, were 
used for the intensity as well as for the dip, and their poles, 
therefore, were not reversed. They were always used in pairs, 
and the correction determined for the mean result of R L1 and 
R L2 was+8, and that for RL3 and RL 4,+ 16. 


MAGNETIC SURVEY OF GREAT BRITAIN, 75 


The remaining five needles were observed in the usual eight 
positions, but in consequence of imperfect workmanship re- 
quired corrections, which, by comparison with the standard 
needles, were assigned as follows : 

J=+4+7 C2=+5 R3=-—8 
C=+42 C3=+8 
Wherever these needles are employed, the proper corrections 
_ are applied in a column in the table headed “ corrected dip.” 


TaBLE XV. 
Captain J. C. Ross’s Observations of the Dip. 


S Poles. 
Station. Date. Hour. | 3 Fgh edad Mean. Sees i Mean Dip. riggs ad 
1837. | hm 4 
Aug.9}1 0 ra] J |e 69318), , |,, 
B 68 46 69 8969 15-9 |) 
3 0pm) C |e 69 O1 
66928 |69141\69161|| . , 
RL 1| 69 27:3 9 16:05) Westbourne 
RL 2| 68 59-1 | 69 13-2 | 69 16-2 Green, Har- 
Cl1l¢269 42 row Road. 
B 69 17°8 | 69 11 69 16 
C |a 68 58-4 
B 69 41:3 | 69 19-9 | 69 21-9 
RL 1| 69 35-1 
RL 2| 69 10-1 | 69 22:6 | 69 25-6 69 24:5 |In the garden| 
RL 2} 69 76 of Bushey 
RL 1| 69 885 |69 23 | 69 26 Lodge. 
J |« 69 92 
B 68 256 | 68 47-4 | 68 54-4 
C |a 68 39:8 
B 69 11-1 | 68 55-4 | 68 57-4 | } 68 55-9 |In the garden 
Noon RL 1) 69 82 of Tortington 
RL 2) 68 37:6 | 68 52-9 | 68 55-9 House, near 
Arundel, 
5 l5em.| RL 1) 69 46:8 
5 302m.) RL 2| 69 26:8 | 69 368 | 69 39:8 
Noon C |a 69 26°5 
B 69 49°6 | 69 38:1 | 69 40:1 69 41°] |In the garden 
3 40rm.) J |e 69 575 of the Wheat- 
B 69 15-6 | 69 86°5 | 69 43°5 sheaf Inn. 
Noon |RL 2} 69 52 
30e.m.) RL 1} 7016 |70 4 |70 7 
C |a 69 45:3 
B70 3:9 |69 54-6 | 69 56:6 70 05 |In a field hal: 
J |e 69 26 a mile south 
687016 |69 51 |69 58 of St.Martin’s 
Church. 
RL 1} 70 198 
RL 2} 69 57:6 |\70 87 | 70 11:7 In the garden 
C \a 69 54:6 of the New 
B 70 21:6 |\70 8-1 |70 10-1 7O 9-7 | Inn. Old 
J |a 70 24:2 Church, N. 
B 69 36:4|70 03170 7:3 34° W.(true) 


half a mile. 


76 


Station. Date. 
1237. 
Birkenhead...|Sept. 18 
— 19 


Douglas, (Isle| — 21 
of Man). 


Birkenhead...| Oct. 11 


bo 


Pwllheli ...... — 14 
Marlborough.| — 17 
Clifton...... | — 21 

— 22 


— 
o PO NO —@= NN & SC 


= 
—) 


Pembroke ....| — 25 


Swansea eos... 


Hour. 


hm 

30 p.m. 

4 45 

9 504.m, 

Noon 
A.M. 

0 30e.m, 

2 0 p.m, 


4 0 p.m. 


Noon 
30 p.m. 


15 p.m. 
45 vo. 


45 a.m. 


Needle, 


WAS HS 


Or bO bo 
CORNISH © AOD SY GS Vornwrn 


BWRBDR 


WRB 
wm Co Co bo bo 
BASS & 


wo 
— bo 
DWRDR DRDR 


APRAYNUIR ANANAD AAAAAD SAAAWAWSHND BVSVWWVNY VBWNeawys ys YBvyyy ys YBuvwua so 


weoypeueooce ecooeovs eomowwwoe weomonmwoworv eooeooo cooecoeoo Set et et et eo'S'e So 
SSSESS RSGESS 


NRO WH Pook 


esis) 
mt bO oe 
DBWRDR 
nown 


aa 
WI BW Ise 


BWRWR 
ee OTR GO 


oe 
to toe 


PRBR 


hs 

o> Hh SI) BE Tb a SR mR oN ee REL co WAL cm cen oat SPIE o> 7 ol weet em ET all i Te) 
toe 
m bo ore 

BUSS BSED St} GRINNED ES OR) SOS 


eis) 
Noe 
DSRDR 
co Orb 
WR RDSWM SNABRAARHE ANwworn 


Mean. 


ie} ‘ 
70 37:1 


70 32°6 
70 26°8 


71 21:8 
71 161 
71 11 


70 31°6 
70 25 
70 37°4 


70 30°4 
70 20°35 
70 34:5 


69 21 
69 19 
69 24:2 


69 30°8 
69 25°8 
69 33:4 


69 48:7 
69 48-2 
69 55°8 


69 37:6 
69 41°6 
69 45:8 


EIGHTH REPORT—1838. 


Corrected 
‘Dip. 


O: ius 

70 40:1 
70 34-6 
70 33°8 


71 24:8 
71 18-1 
71 18 


70 33°6 
70 32 
70 40°4 


70 32-4 
70 27°5 
70 375 


69 23 
69 26 
69 27:1 


69 32:8 
69 32°8 
69 36-4 


69 53-7 
69 55-2 
69 58:8 


69 42°6 
69 48-6 
69 48:8 


Mean Dip. 


UA YY Sa pS a {ESE | EES a ae | eee Sea | ees as 


Place o} 
Observatio 


70 36-2 |In the ga 
of the Ho 


71 20°3 |Inthe gro’ 
of Castle ly 
na. 


70 35:3 |In the gare 
of the hote 


6 


70 32-5 |In the garé 
of the Fe 
Crosses I 


> 


69 25:4 |In the wo 
S. W. of t) 
Castle Inr 


In the gard: 
of the Roy 
Gloucester 
Hotel. 


69 34 


¥ 


” 


69 55°9 |In the gard 
ofthe Drage 
Inn. Per 
brokeChur 
North ( nag, 
half a mile, 


69 46-7 |On the sand 
about half 
mile west 
the Pier. 


MAGNETIC SURVEY OF GREAT BRITAIN. V7 


Poles. 
a direct, Mean, 


Corrected A Place of 
G reversed. = Se 


Observation, 


O) A 

a~68 595 )5 , ants 

670 4:1 |69 31°8 |69 36:8 |) 

a~69 4 

B70 46 |69 34:3 | 69 36:3 ote: 

@ 69 51:2 4 69 36-9 |In the garden 

669 7 |69 29-1 |69 36-1 of Rock Cot- 
69 50:9 tage, the resi- 
69 19-9 | 69 35-4 |69 38-4 |J dence of B. 


L. Coxhead, 
68 43:8 Esq. 


69 56 |69 19:3 | 69 24:3 
69 14:5 
69 25:1 |On the sands 


opposite to 


69 36:7 | 69 25-6 | 69 28-6 


B68 45 |69 15-4 | 69 22-4 the town. 
C 2a 68 35 
6 69 39:8 169 7:4 |69 12-4 
J | 69 348 P 
5 4 5 = d i = 
Lee B 3 46-4 69 10-6 |69 17-6 | $69 16-1 fe barng Si 
RL 1| 69 28-2 |69 15-3 |69 18:3 Near the Wendel 
pillarat thenorth 
C la 68 42-9 foe heey 
B 69 37°5 |69 10:2 |69 15-2 
J |a 69 37 y 
668 48 |69 12:5 |69 19:5 | $69 18-5 |In a field East 
RL 1 of the First & 
RL 2} 69 7 |69 17-9 |69 209 Last Inn in 
C2 
if B 69 27°3 |68 55:8 |69 08 
a B 68 36-8 |68 58:4 169 5:4|469 6-2 |In the garden 
RL 68 568 |69 9-5 |69 12-5 nzum, 


ra 
J 
668 468 |69 8 |69 15 69 17:3 |In a field, Ex- 
RL Cathe- 
RL 69 4-6 |69 17-4 |69 20-4 dral, S.E. 13 


mile. 


C Qa 
; | 68 57-5 |69 2-5 wee 
a 
B 68 59 |69 6 69 6:7 |In the garden 
RL of the Bush 
RL 69 85 |69 11:5 Hotel. 


69 5:8 |69 10:8 
69 8 |69 15 
69 14:6 | 69 17:6 


to Poko Sth wht 
SRE SS RAS 


WRBDS 
AAAHBAMAD AHAoOAIIWS 


69 145 [In a field, 


B 69 45-7 |69 11-4 | 69 16-4 | 


SOHOOH BNODOS 
AAanwdawy WHmonne 


Od 
Ciara 


thedral w.s.w. 
(mag.)13mile 


78 BIGHTH REPORT—1838. 


eo 
: 3 Poles. Corrected . Plac 
Station. Date, Hour. 3 a% greet, Mean. = Dip. Mean Dip. | Opser 
1838. |h m aes 
Southsea ...... Dec. 8/11 20am.) C 2)a 68 21:4], , pact 
B 69 25-8 | 68 53-6 | 68 58-6 
1 20em.) J |e 69 17 ey pit 
B 68 30°6 | 68 53°8 |69 0-8 69 0:4 |In the 
2 40 RL 2} 68 49:2 of the 
8 30 RL 1| 69 8-4 |68 588 |69 1:8 Hotel. 
Guildford,,,..| — 12} 2 P.M. C 2) a 68 20:9 
B 69 33°7 |68 57:3 |69 2:3 
3 30rM.| J |a« 69 20-1 
B 68 36:9 |68 58-5 |69 5-5 69 5:1 |Ina fiel 
— 1311 am) RL 2| 68 54 mile eas 
RL 1} 69 148 |69 4:4 |69 7:4 Town 
London.,....,..| Mar. 6} 1 P.M. C 3) a 68 33:6 
B 69 40°7 |69 7-2 | 69 15-2 
sie P.M. C 3\e 68 33:3 
B 69 41:6 |69 7:5 | 69 15°5 - 
April10) 1 50r.m.) C 3) a 68 36:2 
B 69 41:2 |69 8-7 |69 16-7 
4 P.M. z 68 36 69 14:7 |Westbo 
B69 29 |69 2:5 |69 10:5 Green, 
— 25|11 20a.m.| R 3) ae 69 561 row R 
B 68 49-8 |69 22:9 | 69 14:9 
9 am) RL 3) 69 37 
RL 4| 68 54:5 | 68 59-1 | 69 15-1 
Margate....... —17;2 em.) RL 3} 68 48 
RL 4| 68 37-8 | 68 42-9 | 68 58:9 
4 20r.u.| R 3)e 69 32:8 
B 68 822 |69 2-5 | 68 54-5 68 57-2 \In the 
C 3\a 68 18 of the 
B 69 226 |68 50:3 | 68 58:3 Ancho 
York...cocevvee}| — 27| 2 30r.m.| RL 3) 70 33:7 
RL 4) 70 23:5 |70 286 | 70 44°6 |) 
4 10r.m.| R 3iae 71 19:7 
B7017 |70 48:3 |70 403 
— 2810 am! R la 71 27:8 70 45-2 |In the 
B 70 25-2 | 70 565 | 70 48-5 of the 
Noon | RL 3} 70 345 Keys FE 
RL 4} 70 28:2 |70 31:4 | 70 47-4 
Scarborough, | May 1} 1 40r.m.) RL 3) 70 325 
RL 4| 70 21:6 | 70 27:1 | 70 43-1 
3 pM, R 3)e 71 28:3 70 43 «=«(|In the 
B 70 13:2 |70 50°8 | 70 42:8 of the 
Inn, & 
Bridlington.... — 3) 9 l5a.m.) RL 3] 70 27:4 to the 
RL 4; 70 21:3 | 70 24-4 |70 40-4 Church 
11 10 R 3) @ 71 24:8 ; 
B70 5:4 |70 45:1 | 70 37-1 70 38-8 |In the 
dl pM.| RL 3) 70 27:3 of the 
RL 4| 70 187 |70 23 |70 39 Inn 


79 


Place of 
Observation, 


In the grounds o} 
Wadworth Hall, 
the seat of R. J. 

Coulman, Esq. 


Nottingham 
Church, §.S.E, 
13 mile. 


In a garden at 
Callington, 


Louth Church, 
S.W. 1 mile. 

In the garden of 
the Wool-pack 
Inn, River-head. 


Inthe grounds 
of the Suffolk 


of Harwich. 


Westbourne 
Green, Har- 
row Road. 


ton’s nursery 
grounds, 


sO EIGHTH REPORT—1838. 


Fa Poles. 
Station. Date. Hour. g yeas ’ Mean. ee Mean Dip. once 
1838. | h m Ons 
Stonehouse....| Sept. 1} 2 45p.m.) R6e71 173), , 
B71 27:3 | 71 22-B | cscrsesecees 
4 15pm.) R 4)e@ 71 255 7) 24-1 |Intheg 
= B71 26-4 |71 25°9 | ....... asees of Ston 
theseato 
London........ Dec. 4/10 45a.m.) R 4) a 69 19°3 Sir Hew 
B 69 11-7 169 15-4 | «eee 7} 
0 30r.m.| R 5j)2 69 83 
B 69 17-4 | 69 12°8 | .........00- 
— 10) Noon R 6)2 69 12:3 
B 69 19°6 |69 15-9 | ...... ddoves 
2 pm.| R 7/)e 69 13:9 
B 69 14:9 |69 14-4 | ..scccesece 


Table XVI. contains the latitudes and longitudes of Captain 
Ross’s stations, with the mean dip at each station reduced to the 
Ist January, 1838, being the middle period of his observations. 


TABLE XVI. 
ee Dip, i Dip, 
ation, Lat. | Long. |) Jan, 1338, Station. Lat. | Long. |; jan, 1838. 
9 Ud Oo 4 (2 Rigt f ie) 4 oO 4 Oo 74 

Berwick ... |55 45| 2 00) 71 43°6 | Ilfracombe ... |51 12| 4 06] 69 36:5 
Stonehouse . |54 55] 2 44! 71 25-7 | Clifton......... 51 27| 2 35) 69 33:5] - 
Douglas ... |54 10) 4 28) 71 19°6 | Lowestoffe ... |52 28/—1 50) 69 30-2 
Newcastle... |54 58} 1 36) 71 14:6 | Marlborough. |51 25] 1 43) 69 24:9 
Gh =e 53 57| 1 06) 70 46-0 | Padstow ...... 50 33| 4 56) 69 24:8 
Scarborough |54 18| 0 26] 70 48-8 || Bushy ......... 51 38] 0 22) 69 23:6 
Bridlington. |54 08| 0 14) 70 39-6 || Land’s End... |50 05| 5 40| 69 183 
Birkenhead. |53 24] 3 00} 70 35-1|| Exeter......... 50 43| 3 31) 69 17:1 
Pwllheli ... |52 55| 4 23) 70 32-0|| Harwich ...... 51 56|—1 13] 69 16-4 
Wadworth... |53 28} 1 07) 70 26:6|| Falmouth ... |50 09| 5 06] 69 15-8 
Louth ...... 53.19] 0 0} 70 18-6] London .,.... 51 32} O 11) 69 15-4 
Nottingham |52 57] 1 08} 70 15-4]| Salisbury...... 51 04} 1 48) 69 14:3 
Stafford...... 52 48] 2 06) 70 09:0 || Weymouth ... |50 37] 2 27) 69 06-5 
Birmingham | 52 28] 1 53] 69 59-7 || Plymouth ... |50 23| 4 07] 69 06:0 
Pembroke... |5] 39] 4 54) 69 55:5 || Guildford ... |51 14] 0 34| 69 05-0 
Cromer ...... 52 56|—1 19) 69 47-0|| Southsea ...... 50 48| 0 58) 69 00-2 
Swansea ... |51 36) 3 55) 69 46:3 || Margate ...... 51 23)—1 23) 68 57-9 
Daventry ... |52 16} 1 08) 69 40:3 || Tortington ... |50 50) 0 34) 68 55-0 


If we combine the results at these thirty-six stations by the 
method of least squares, we obtain the following values : 
w=4+°1974; y=—'5114; w=—68°54!; r=0'548; and 
5=69° 534 at the mean geographical position of 52° 16! N., 
and 1° 55! W. 


Major Sabine’s Observations.—These observations were 
made at fifteen stations, with a 94-inch circle, and two needles 
by Gambey, (Table XVII.); and at twelve stations with a circle 
of Nairne and Blunt of 11 inches in diameter, and a needle by 
Robinson, designated as § 2, (Table XVIII.) 


< 


Sone 


MAGNETIC SURVEY OF GREAT BRITAIN. 


TaBLeE XVII. 


Major Sabine’s Observations of the Dip with Captain 
Fitz Roy’s Gambey. 


81 


Station. Date Hour 
1837. gen 
Tortington Aug. 15 
— 1b 
Birkenhead...| Sept. 17 
— 18 
Aberysthwith.. — 21/1 vm. 
— 21/2 em. 
Dunraven — 26 
Castle ...... Jee 
— 28 
Tortington ...) Oct. 16 
—17&19 
Dover .........| Nov. 2) 35 p.m 
— 7 Iilgem 
— 6) 3 paw 
Margate ... — 9 
s— 9 32 rar 
— ll 
Regent’s Park,|— 15 & 16 
London ... 
— 16 
1838, 
Lew Trenchard July 19) Noon 


— 21/11 a.m. 


rm bo to = 


bt wo wo wb 


— 


bm em bt tO HO WO WH WHO 


2 
2 


* Observed by Viscount Adare. 

¢ Observed in various azimuths. 
Observers, Capt, Johnson, R.N., and Major Sabine, 

| Observed by Capt. Johnson and Major Sabine, 

VOL, vil, 1838, G 


§ In various azimuths. 


Poles. 
M h 

hp en Pica Seen 
9 05-1 
az 
a 68 bas f se lte es 
a 68 56-4 
p69 021 f 68 59:3 
z 70 30°6 
270 40-0 | 79 353 bro ral: 
a 70 33-0 
270 367 }|70 34°85 
« 70 20°6 

2 70 261 }\70 28°85 vee 
2 70 283 70 23-60 
8 7017-9 
ate oat 
2 69 42: 
aes 69 45-7 
ur 
f 69 48: f 6945-4 * 
a 68 518 
B68 566 fo 42 ne: 
# 68 55°8 } eg 54.9 
B 68 56-4 t 
@ 68 51-1 
2 63 541 | | joss + 

68 51°6 
6 68 530 0 } 68523 + 68 52:3 
a 68 54:0 
2 68 498 f OB 519 + 
a 68 59-4 
B69 ox1 f (69 0275 
spar 
2 69 00-8 f 69 05:3 foo ona 
a 69 041 
2 69 03-7 69 02544 
3 \|o023-9 ¢ 
a 69 20-7 foo 2a 
ar| 69 23:1 || 
a 69 136 : 
869 ora 69 17-9 sine 
# 69 17°91 \gg 20-2 
B 69 22-5 


Place of 
Observation, 


On, and _ be- 
neath the} 
Cliffs, 


+ Observed in various azimuths. 


82 EIGHTH REPORT—1838. 


o 

= Poles. 

3 Mean at the Place of 
3 pi Baas yet Stations. Observation, 


Whitehaven... 


Newcastle ... 


Alnwick Castle’ 


Stonehouse ... 


pee mite 19.9 f|7217-0 | 7217-0 [Fields nearthe 
Jordan Hill... | 2 le 72 Pht bike Baths Hotel. 
B72 15-0 
et }\r2 164+ 
2 & 72 14:3 |Inthe grounds 
: } 7211-1* of > iaiasties 
2 Smith, Esq. 
fs i 72. 15-8* 
anh she 69 set 6906-7 | 69 06-75 |Inthegrounds 
sete eene ess | 43 pom, 9 14- , 
9 18:2 of the Palace, 
ST Se DG) OR SR WEE SS oT 


* Observed by Archibald Smith, Esq. 


MAGNETIC SURVEY OF GREAT BRITAIN. 83 


TaBLeE XVIII. 


Major Sabine’s Observations of Dip. Needle, 8 2. 


Station. Date. Hour. 


Mean. Cc oue cted Place of 


Observation, 


| | 


69 06-7 eeves, Esq. 
69 26-3] | 69 28-15] 69 18:55 cere Gar- 
Waecse 27 69 29°8 dens. 


eee! te M. }70 34-45 |79 24:85|Fields near the 


ins Gar House of Industry, 
at 1f aa i 35-6 }70 35-5 |70 26-9 |Hill north of the 


t . town. 
22) 6 a.st.|70 12-6) | 79 19.75| 70 03:15|Garden of the 


Regent’s Park, 14| 14 p.a.|69 2 nine Terraces 


London ....... 14| 22 p.m,|69 a7. 2 69 29-72) 69 20:12;/Mr. Jenkins’ 


— 92| 62 a.01|70 12-9 pale 
2 . . 
Merthyr ......5. = ie ai mace ae }70 13:5 |70 03-9 |Mr. Thompson’ 
Dunraven Castle] — 25] 23 p.m./69 58-8 erounds, 
— 25| 34 v.m.|69 57:9) +69 57-4 |69 47°8 |In the Castle- 
Oct. 3| OF v.m.|69 55:5 grounds, 
Tortington ....... — 15] 4 r.a./6907-9)] 69 og.) | 68 565 |In the groundso 
— 19 1 pent 69 04:3 W.L E 
Dover ........006 Nov. 2 p.m.|69 01:0 athens Saas. 
— 8 3 p.m.|69 03°8] $69 02-2 | 69 52°6 |On and beneath 
— 6] 2 »™.j6901°8 the Cliffs. 
Margate .........| — 9 69 08:2 eS : 
g = 1o)tr, sche 128 } 60 10-4 |69 00°8 |FieldbehindMa- 


14| 3° v.m|69 34-2 nursery- 
16| 23 v.m.|69 30°6 grounds. 
1838. 
Jordan Hill ..... Sept. 13] 1 p.m.|72 22-0 72 21-4 172 118 Inthe groundsof 


— 13] 2 v.m.|72 208 J. Smith, Esq. 
Kew ....eeessereee] Oct. 13] 14 v..|69 24-0) 69 24:0 | 69 14:4 |In the gardenso 
the Palace. 


Note on the correction applied in Tables X PII. to the Dips 
observed with 2. This needle being employed for the statical 
measurement of the variations of the intensity, the poles were not 
reversed in the dips obtained with it. The ‘observed dips”’ in 
Table XVIII. are consequently a mean of four positions only of 
the needle and circle; namely, of the circle in the azimuths 0° and 
180°, and the same repeated with the needle reversed on its sup- 
ports; both ends of the needle being read, and ten readings taken 
in each position. There are twelve stations at which the dip was 
thus observed with S 2; at eight of these it was also observed 
with Gambey’ s instrument, in which the poles of the needle were 

G2 


we SA 


84 EIGHTH REPORT—1838. 


reversed, and the observation was consequently complete. At 
the other four stations Gambey’s circle was not.employed, and 
we have to deduce from the observations with S 2 the dips that 
would have been shown by a needle with the poles reversed. In 
the report of the Magnetic Observations in Scotland, (B. A. re- 
ports, vol. vi. page 98,) a correction for this purpose was de-. 
rived from a comparison of results obtained at Limerick with 
S 2, and with a needle on Mayer’s principle, used in a circle 
of Nairne and Blunt’s; and we have here observations at eight 
other stations, furnishing materials for a similar comparison 
between the results of S 2, and of Gambey’s instrument. 


TABLE XIX. 


Dips observed. oe oe oe : Weis 
‘ eight. 
rT nn, 
aie Mayer or $2. ath oad nt+n. 
$2. Gambey. =e |=n.| =n. | =n. |exn. 
Limerick® .......+. fi 14-63 | 71 0327 |4+1136110| 5 | 33 | 37-49 
Tortington (Aug.)| 69 11-2 68 59-6 |+11°6 2 2 1-0 | 11:60 
Aberysthwith ...... 70 35-45 | 70 23-5 |+11:95 | 2 2 1-0 | 11-95 
Dunraven Castle 69 57-4 69 45:7 | +11-7 3 3 15 =| «17-55 
Tortington (Oct.) .| 69 06-1 68 54-8 | +11:3 2 10 1-7 | 19-21 
Dover ecco. 69 02-2 68 523 |+ 9-9 3 5 1:9 | 18°81 
Margate .....ss.000 69 10-4 69 02:99 |+ 7:5 i: 5 14 | 10:50 
Regent’s Park ...| 69 29:7 | 69 23:3 |+ 5-9 4 8 25 | 14:75 
Jordan Hill ...... 72 21:4 72143 |4+ 71 2 4 1:3 9-23 
Kew Gardens...... 69 24:0 69 16-45 |+ 7:55] 1 1 0:5 3°78 
16-1 | 154-87 
Mean error of S 2 when the poles were not reversed......... +9°6 


* The observations at Limerick with S 2 and Mayer’s needle have been already 
detailed in the 6th Report of the British Association, page 98. As the comparison 
of their results is slightly affected by employing a different rate of annual decrease 
for the purpose of reducing the observations to a common epoch, they are stated 
afresh. 


No. of Mean, allowing 
Hove Observed Dip. | January 1836. | weight for the 
ets. number of Sets. 


July 1835 
Dec. 1835 
Feb, 1836 
May 1836 


Nov. 1833 : : 
May & June} : , : \n 03:27 
1836 i 


MAGNETIC SURVEY OF GREAT BRITAIN. 85 


A correction is therefore required of—9! 6 to all the dips 
observed with S 2. The application of this correction pro- 
duces the final column in Table XVIII., entitled ‘‘ Corrected 
Dips.”’ 

in Tables XVIII. and XIX., we have, then, the dip observed 
at fifteen stations with Gambey, and at four additional stations 
with S 2, making in all nineteen stations, which are inserted 
in the following table with their geographical positions, and the 
dips reduced to the mean epoch of the observations themselves, 
viz. the 1st January, 1838. 


TABLE XX. 

Stati Dip, i Dip, 
ion. Lat. | Long. |j.7 7.1838. Station, Lat. | Long: | yan. 1. 1838. 

O74 [o} U / [e) 4 
Alnwick cei. ae Dunraven Castle|51 28] 3 37| 69 45-0 
Castle ...... 55 25| 1 42 | 71 24-2|/Regent’s Park |51 34|- 0 10) 69 23:5 
Stonehouse ...|54 55] 2 44 | 71 21-1 ||Lew Trenchard |50 40] 4 10} 69 20:3 
Whitehaven ...|54 33| 3 33 | 71 12:4||Kew Gardens...|51 29} 0 18] 69 18:3 
Newecastle...... 54 58] 1 36 | 71 10°6||Westminster ...)51 31] 0 07] 69 17-5 
Birkenhead ...|53 24] 3 00 | 70 34:4|/Falmouth ...... 50 09} 5 06) 69 13:3 
Shrewsbury ...|52 43| 2.45 | 70 24-2||Worcester Park |51 23] 0 17} 69 08-6 
Aberysthwith |52 24] 4 05 | 70 22-8 ||Margate ......... 51 23/—1 28] 69 02-6 
Merthyr ...... 51 43] 3 21 | 70 03-2 |/Tortington ...... 50 50] 0 34] 68 55:5 
Brecon ......... 51 57] 3 21 | 70 02-5 || Dover ............ 51 08/—1 19} 68 51:9 


Combining these by the method of least squares, we 
obtain the following values: x=+'2305; y=—'498; 
u=—65° 08'; r="548; andd=69° 566 at the mean geogra- 
phical position, of which the latitude is 52° 18’, and the longi- 
tude 1° 59!. 


If now we collect in one view the several values of w and 7 
which have been thus obtained from the observations in Eng- 
land, we havé as follows: 


TasBLe XXI. 
M G hical 
Observer. No. of Position. & vee 
Stations. 

Lat. Long. Ue Tr. 
~ es 29 bz 45 249 || —62 41 | 0580 
Lloyd BS sce 14 52 04 1 43 —63 15 0-644 
Phillips 24 53 49 2 08 —63 14 0-590 
Ross Raunep ase scssas 36 52 16 1 55 —68 54 0-548 
Sabine ...... Aree 19 52 18 1 59 —65 08 0-548 


86 EIGHTH REPORT—1338. 


If we regard the several values of w and r as entitled to 
weight proportioned to the number of stations of which each is 
the representative, we obtain —65° 05! and 0''575 as the mean 
values of w and r derived from the English series, corresponding 
to the central geographical position 52° 38! N., and 2° 07' W. 


Section I].—Scornanp. 
Observations of Captain J. C. Ross.—These observations 


were made with Robinson’s six-inch circle, and the needles 
R4, R5, R6, and R 7, which have been already described. 


TaBLe XXII. 


Captain J. C. Ross’s Observations of the Dip, Scotland. 


oles. 
Station. Date. Hour. E afcirect, | Mean, — Peis 
1838. Oued ou o 4 
Aberdeen ...| July 18.) 4 p.m.|R 4| «& 72 28:7 
B 72 25°7 |\72 27-2 In a field 
1 p.m.|R 5] « 72 30 72 27°6| one mile 
B 72 25°8 \72 27-9 south of the’ 
city. 
Lerwick ...... — 24) Noon |R 4) «2 73 503 
B 73 46-9 73 48-6 
2-15 p.m.|R 5) « 73 43 
B 73 41°6 73 42°3 
— 25) Noon |R 6) « 73 41:8 
B 73 46-4 |73 44:1 Gardie- 
— 27| Noon |R 6| « 73 44:8 73 44-9|House, Bras- 
B 73 47°8 \73 46°3 sa Island. 
1-40 p.m.|R 4| « 73 48-9 
B 73 43°3 73 46-1 
3 p.m.|R 5] & 73 43-2 
B73 41 73 42-1} } 


MAGNETIC SURVEY OF GREAT BRITAIN. 87 


Poles. 
Station, qelitect; | Mean.) "Dip" | observation. 
(e] ‘ Oo¢ Qed 
Kirkwall...... R Ae 24:7 a 
B 20° 1/73 22-4 
Rosle 13 20 4 tiered 
B 73 19+ 4\73 19-9) +73 20-4 Ghenan Fall 
R 6) a 73 16 9 bes 
B 73 21: 1173.19 ‘ 
Wick ......008 a 73 27: 6 
B 73 18> 3/73 22:9 Inthe garden 
«73 15:7 oO Rose- 
B 73 17: 1/73 16-4] +73. 19-9] bank, the 
“a73 17° 5 seat of Mr, 
B 73 23+ 3\73 20-4 M‘Leay. 
Golspie ...... 2730: 3 Dunrobin 
8736 8733-5 Castle, E. 3 
2W37 3 73 4-3) of a mile.— 
B73 3: 2\73 5: 2 _ | Inthewood, 
Inverness..,.... @ 72 51-11 
j B 72 43° 1/7247-2 
oT ae 3 Inge garden 
B 72 47: 4/72 43-5) $72 46-2 donian Ho- 
a 72 46° 1 tel. 
B 72 49: 672 47:8 
Culgruff...... a 71 36: 4 In the grounds 
B 71 37: 371368 sata Gass 
a 741 31: 8 7135-7} Clark Ross, 
B71 37: 671 34-7 Esq. 
Jordan Hill . a 72 15° 6 In th 
72 19 872177 of Jordan Hil 
a 72 21:6 72 20 tl e seat oO: 
B 72 22+ 872 ve ue, Fe 
Berwick ...... a 71 35 In agarden half 
B71 41: 617138-3 a mile north o: 
a 71 46 Lars a 
B71 45: 1/71 45-6} J 
Dunkeld ....,. a 72 23° 9 In a planta- 
B 72 23: 1/72 23-5 tionoflarch, 
a 72 26° 8 Craigie 
B 72 22- 872 24-8 Barns,S.W. 
a 72 22:2 72 23:1 by W. three 
B 72 22+ 2\72 22-2 or four 
a 7218 9 miles. 
B 72 24: 9\72 21-9 
| 


&8 EIGHTH REPORT— 1838. 


Table XXIII. contains the latitudes and longitudes of Captain 
Ross’s Scottish stations, and the mean dip at, each station at 
the dates shown in the preceding table. The whole interval 
in which they are comprised is so short, that no reduction 
to a common epoch has been applied. 


TABLE XXIII. 


Station. Lat. | Long. Dip. | Station. Lat. | Long. Dip. 

ie} / Oo 7 ie) / fe] 4 ° 4 fe} 4 
Lerwick ..|60 09] 1 07 | 73 44:9|| Aberdeen ... |57 09] 2 05 | 72 27-6 
Kirkwall ... |59 00} 2 58 | 73 20-4|} Dunkeld...... 56 35] 3 33 | 72 23-1 
WWiteksesss-s-> 58 24] 3 05 | 73 19-9|| Jordan Hill... |55 54] 4 21 | 72 20-0 
Golspie...... 57 58| 3 57 | 73 04:3]| Berwick ...... 55 45| 2 00 | 71 41:9 
Inverness ... |57 28] 4 11 | 72 46:2}) Culgruff...... 54 58] 4 00 | 71 35°7 


If we combine these ten results by the method of least 
squares, we obtain the following values: w= +250; 
y=—'484; u=—62° 39!; r=0'-545; and 5=72° 40'8 at the 
mean geographical position 57° 20' N., and 3° 08! W., and at 
the mean epoch August 18, 1838. 


Major Sabine’s Observations—These observations were 
made at twenty-seven stations in the summer of 1836, with a 
circle by Nairne and Blunt, and the needle S 2 of Robinson. 
The details have been already published in the 5th vol. of the 
Reports of the British Association, and need not therefore be 
repeated in this place. When that Report was published, the 
correction of S 2 was provisionally taken as —12'; it has since 
been more correctly ascertained to be —9'*5 by a much more 
extensive series of comparative observations; (Table XIX.) The 
subjoined table (X XIV.) contains the latitudes and longitudes of 
the twenty-seven stations, and the dips, to which the new correc- 
tion of —9!-5 has been applied. As the whole of these obser- 
vations were comprised within an interval of six weeks, no 
reduction to a mean epoch has been thought necessary. 


MAGNETIC SURVEY OF GREAT BRITAIN. 


TaBLE XXIV. 


Station. Lat. 
hes 

Tobermorie ...|56 38 
Loch Scavig...}57 14 
Loch Slapin...}57 14 
Golspie......... 57 58 
Inverness ...... 157 27 
Artornish ...... 56 33 
Gordon Castle 57 37 
Fort Augustus! 57 08 
Rhynie......... 157 20 
Loch Ranza...155 42 
Alford ......... 57 13 
Newport ...... 56 25 
Glencoe ...... 56 39 
Helensburg ...|56 0 


Obs B® tO oR OO GO 
Sor oOkeH AIOo oO. 
NooCornNnN- 


5 07 
4 41 


72 17:1 
72 16:7 


Station. | Lat. Long. 
s_lous 

Loch Ridan 55 57| 5 10 
Castle Duart ...)56 31] 5 45 
Braemar .......+- 57 01) 3 25 
Kirkaldy ......... 56 07| 3 09 
Loch Gilphead .|56 04] 5 28 
Glasgow ......... 55 51] 4 14 
Great Cumbray |55 48| 4 52 
Campbeltown...}55 23| 5 38 
Blairgowrie...... 56 36| 3 18 
Edinburgh ...... 55 57| 3 11 
Loch Ryan...... 54 55| 4 59 
Melrose ..... «(59 35] 2 44 
Dryburgh ...... 55 34] 2 39 


89 


If we combine these twenty-seven results by the method of 
least squares, we obtain the following values: #=+°337; 
y=—"461; u=—53° 47'; r=0°571; 3=72° 187 at the 
mean geographical position 56° 28’ N., and 4° 19’ W., and 
at the mean epoch September 1, 1836. 


Mr. Fox’s Observations.—These observations were made 
with Mr. Jordan’s 7-inch circle and needle, and are as follows : 


TABLE XXV. 


Mr. Fox’s Observations of the Dip in Scotland. 


— Station. Date. 

1837. 
Melrose ...... Aug. 26 
Edinburgh...) — 28 
Edinburgh...) — 28 
Linlithgow ...) — 30 
Inverary ...... — 3l 
Loch Lomond] Sept. 1 
Glasgow ...... — 4 
Moffat ......... — - 6 
Gretna Green| — 6 


Hour. 


114 a.m. 
8 «aM. 
6 P.M. 
13 P.M. 
6 P.M. 
5 P.M. 
4PM. 
8 A.M. 

2 P.M. 


Lat. 


ie} / fe} 4 
55 35) 2 44 
55 57 
55 57 
55 59 
56 15 
56 18 
55 51 
55 20 
55 01 


Long. | Dip. 


3 11 
3 11 
3 37 
5 04 
4 40 
4 14 
3 27 
3 04 


71 53 |Botanic Garden. 
72 7\In the Park. 
72 5|Botanic Garden. 


71 40|Near the Inn. 
71 29|Behind the Inn. 


71 38|East of the Abbey. 
71 47 |Gard. opposite Princes St. 


Place of Observation. 


71 59|Near ruins of the Palace. 
72 15 |Lakeside near Tarbet. 


<a 


90 EIGHTH REPORT—1838. 


The portion of country over which these observations extend 
is too limited to afford an advantageous contbination for the 
deduction of the values of « and 7; I have therefore combined 
them with my own twenty-seven results in Table XXIV., 
forming an united series of thirty-six stations towards the final 
deduction of the values of « and r in Scotland, Mr. Fox’s ob- 
servations having been previously reduced to September 1836, © 
From this combination we obtain the following values; «= 
+°320; y= —'447; u=—54° 20's r=0'550; 3=72° 13°2 at 
the mean geographical position 56° 18’ N., and 4° 10! W. 


If we collect in one view the values of uw and » which have 
been thus obtained from the observations in Scotland, we have 
as follows: 


TasLe XXVI. 
Mean Geographical 
Observer. No, of orition. big 
Station. 
Lat. Long. u. vw. 
ely Y ou (oho 
WROSS onseasepnesmanctee 10 57 20 3 08 —62 39 0-545 
Sabine and Fox...... 36 56 18 410 —54 20 0-550 


Regarding the values of w and r as entitled to weight propor- 
tioned to the number of stations of which each is the represent- 
ative, we obtain w= —56° 06', and r=0°549, as the mean va- 
lues derived from the observations in Scotland, and corre- 
sponding to the central geographical position of 56° 49! N., and 
8° 39' W. 


MAGNETIC SURVEY OF GREAT BRITAIN. 9] 


Section III.—Irevanp. 


(This Section is by the Rev. H. Luoyp.) 


Before entering into the details connected with this division © 
of our memoir, it will be necessary to make a few remarks upon 
the principles of the calculation which has been employed in 
deducing the position of the isoclinal lines from the scattered 
observations. 

If = denote the dip (or intensity) at any station of observa- 
tion; 2%) that at some near station, which is taken as the origin 
of co-ordinates ; and x and y the actual distances (in geogra- 
phical miles) between the stations, estimated on the parallel of 
latitude and on the meridian, respectively,—or the co-ordinates 
of position of the first station referred to the latter as an origin ; 
then I have shown*, (Fifth Report, p. 151) that the relation 
of these quantities is expressed approximately by the equation 


z—2%=Mr+Ny; (1) 
in which M and N represent the increase of the dip (or inten- 
sity), corresponding to each geographical mile of distance in 


the two directions. 


In employing this equation in the calculation of the isoclinal 
and isodynamic lines, I had taken one of the stations of ob- 
servation—namely, Dublin—as the origin of co-ordinates : ob- 
servation, therefore, gave the values of = and x9, and the equa- 


tions of condition thus obtained were combined, by the method 


of least squares, so as to give the most probable values of M 
and N. In a subsequent application of this method, (Sixth 
Report, p. 99) Major Sabine adopted a better course, and 
took an arbitrary station, with an unknown dip and intensity, 
as the origin. 2, was thus unknown, as well as M and N; and 
the resulting equations gave not only the most probable values 
of the increase of the dip (or intensity) in the two directions, 
but likewise that of its absolute amount at some one station. 

Let this latter quantity be denoted by L, i.e. let 29 = L in 
the preceding equation ; then each observation will furnish an 
equation of condition of the form 


L+ Me + Ny=«. (2) 


Combining these equations by the method of least squares, we 
have the three following final equations : 


* The notation here used is somewhat different from that employed in the 
Report. The variation can cause no embarrassment to the reader. 


92 EIGHTH REPORT—1838. 


LW) + M2 (wr) +NEwy) => we), 

LS (wr) + M2 (wa?) +NEwey) = Twee), (3) 

Li(wy)+MiWwey) +N (wy?) = = (wyaz); 
in which w denotes the weight of the determination, and the 
symbol & the sum of the x values of the quantities within the 
brackets, 2 being the number of separate determinations. From 
these equations, the most probable values of the three unknown 
quantities, L, M, N, are obtained by elimination. 

If the point taken for the origin of the co-ordinates be that 
for which 

Z(w2)=0, wy) =0; 
or be, as it were, the centre of gravity of the stations, the final 
equations are reduced to 
L=(w) = > (w2), 
M & (w 2?) + NY (we y) => (wea), 
MS (wxy) +N (wy?) = 3 (wys). 

The values of L, M, N being obtained, we may apply 
the equation (2) either to determine the value of x, when x 
and y are given, i.e., to deduce the most probable value of the 
dip for a given place,—or, conversely, to infer the relation of 
x and y when = is given, i. e. to determine the equation of the 


line passing through all the points of given dip. In this latter 


application let s — L = K; the equation of the line then is 

Me+Ny=k, (4) 
x and y being the co-ordinates, measured along the parallel of 
latitude and the meridian respectively. On this supposition, 
then, the isoclinal line is a right line ; the angle which it makes 
with the meridian is 


ang (tan =— x) ; (5) 


and the increase of the dip corresponding to each geographi- 
cal mile of distance, in a direction perpendicular to the line, is 
VM? + N®. (6) 

In this mode of computation it is assumed, not only that the 
portion of the earth over which the observations extend 
may he treated as a plane surface, but also that the differ- 
ences of dip (or intensity) are /énear functions of the differences 
of latitude and longitude,—in other words, that the isoclinal 
and isodynamic lines are straight. ‘This supposition may be 
safely made, where the district of observation, itself inconsider- 
able in extent, is remote from the poles of dip or of intensity ; 


7 


MAGNETIC SURVEY OF GREAT BRITAIN. 93 


for in such cases the curvature of the lines not being rapid, the 
curve itself may, for a small portion of its extent, be confound- 
ed with its tangent. It suggests perhaps the best mode of de- 
termining with precision the empirical laws of the distribution 
of terrestrial magnetism ; namely, by means of small groups of 
observations, each of which will give, by this method, not a point 
in the curve merely, but a portion of its tangent. 

The extent of the district in which this method is available 
will, of course, vary with the curvature of the lines on the 
earth’s surface, becoming more and more limited as we approach 
the poles. Where the flexure of the lines is rapid, and we 
seek, nevertheless, to combine the observations scattered over 
a moderately extensive tract of country, it becomes necessary 
to obtain some means of pushing the approximation further. 

Such means readily present themselves. Whatever be the 
laws of distribution of magnetism on the surface of the earth, 
it is manifest that the dip (or intensity) at any station is a func- 
tion of its co-ordinates of is or that 

= F(@,8), 
« and 8 denoting the aren of the station (in parts of 
radius) referred to some neighbouring station as an origin. 
Accordingly, 


j r= 0) +(F)a+ (GB S\e0+3(F ra) + (soap ag) 4 ap 


d? z 


the brackets denoting the particular values of the derived 
functions, when e = 0,8 = 0. The quantities «and £, in the 
preceding equation, being small, we may push the approxima- 
tion as far as we please, by including a greater number of terms 
‘in the development. 

Let the co-ordinates of linear distance be denoted, as before, 
by x and y, 


ae pat; 


r being the radius of the earth. Substituting these values in 
the preceding equation, and making 


See =*(H).P sa 3 (FS): 


ar) = (soap aA): R= 35 2) be ae 


we have 


®=L+Mar+Ny+Pa®?+ Qvuyt+ Ry + &e. (7) 


94 EIGHTH REPORT—1838. 


If we retain only the terms of this equation in which # and y 
are of the first dimension, we have the equation (2) already 
obtained. 

'l'o advance another step in the approximation, we should in- 
clude the terms in which x and y are of the second dimension ; 
and we shall thus have six unknown coefficients L, M, N, P, Q, 
R, to be determined. For this purpose, the equations (in number 
the same as the stations of observation) are to be combined by 
the method of least squares; and the six resulting equations 
will give, by elimination, the quantities sought. 

The coefficients L, M, N, &c. being known, the line of given 
dip is 

Ry+Qey+Px2’+Ny+Me=K, (8) 
in which K denotes, as before, the particular value of = — (z). 
Here, then, the isoclinal line is of the second order; and its 
species is determined by the relation of the first three coeffi- 
cients, P, Q, R. The equation of the curve being found, it is 
easy to construct it graphically by points. 

The preceding solution of the problem is probably suffi- 
cient for all purposes; but the determination of six unknown 
quantities by the method of léast squares, when the equations 
of condition are numerous, is a formidable labour; and it is 
therefore important to consider whether we can safely stop 
short at any step of less generality. Now it is easily seen that 
in most cases to which we have to apply this method, the iso- 
clinal line may be represented by the equation 

P2ti+Ny+Me=K, (9) 
in which there are only four coefficients to be determined*. 
This equation (considered as belonging to a plane curve) is that 
of a parabola. 

The equation, being /inear in one of the co-ordinates, is very 
easily constructed by points. 


* This is evident from geometrical considerations. 
Let L M be a portion of the curve, re- 


ferred to the axes of co-ordinates O P, OL; | ia 

and let L Q be its tangent at the point L, pe See 
. - . . > = 

making with the axis of abscissee an angle =F 

whose tangent is a. The ordinate of the ee BL 

curve P M, is equal to PQ+QM. But N 


P Q, the ordinate of the tangent, is equal to 
aa + b, b denoting the ordinate at the ori- 
gin, O L. And the sagitta Q M, is pro- 
portional to Q L?, the are being small in 
proportion to the radius of curvature ; i.e. 0 P 
QM=kx QI2=hk (144%) a*=ca*% Hence 


y=b +ax+ ca, 


ape 
MAGNETIC SURVEY OF GREAT BRITAIN. 95 


The object proposed in the preceding method has been at- 
tained by Major Sabine by a different process, which will be 
applied by him in the sequel. It is therefore unnecessary to 
make any application of that here laid down. 


In combining the equations of condition by the method of 
least squares, it is manifest that we cannot, in general, allow 
equal weight to all. The result obtained at one station may be 
derived from a single observation only; while, at another, it 
may be the mean of several observations,-made at different 
times, and with different instruments. In a former discussion 
of the observations in Ireland, weights were assigned to the 
results at each station, but on arbitrary and uncertain princi- 
ples. I now proceed to remedy this defect; and I do so the 
more willingly, both on account of the great importance of 
this branch of the theory of probabilities in Physical science, 
and because the results to be referred to are connected with 
researches not as well known as they deserve. 

Let 2,, 7, #3, &c., 2, be m values of the quantity x, ob- 
tained by separate and independent observations; and let a 
denote their arithmetical mean, so that 


1 
a= ~(2 + 2. + 2 + &e. 4+ 2,) 5 


then the probable error of this mean, i.e. the limit on either 
side of which there are equal chances of the actual error lying, 
is given by the formula 


FE? — 2 p° = (# — a)’ 
7 n(n—1) ’ 
in which > (7 — a)? denotes the sum of the squares of the dif- 


ferences of the several partial results and the mean, or the va- 
lue of 


(10) 


(v, — a)? + (% — a)? + &e. + (@, — a)*; 


and in which, also, p is the number which satisfies the equa- 


tion 
—# ee 
ih Pug dt iat 
0 
Numerically, p = 0°4769; and substituting in (10) 


__ *4549 & (« — a)? 
ee ae ‘s 


The probable error of a single result, as deduced from com- 
parison with the rest, is in like manner given by the formula 


96 EIGHTH REPORT—1838. 


"4549 > (@ — a)* ‘3 
Yee se Sd Sl ae ey) Fs 
e = ay ? (12) 
so that e& = n E®. The weights, in both cases, are measured by 
the inverse of the squares of the probable errors ; that is 


WW? 1, ee? od, (13) 


w and W denoting the weights of the single result, and of the - 
mean, respectively*. 

When the quantity sought is a dinear function of two or 
more unknown quantities, which latter are obtained imme- 
diately by observation, its probable error is connected with 
those of the quantities on which it depends by a very simple 
relation. 

Let x and y be the quantities sought by zmmediate observa- 
tion, and let the quantity actually sought, z, be a linear func- 
tion of these, expressed by the equation 


FS pr+gqy. 
Let a denote the arithmetical mean of m observations of the 


unknown quantity 2; 5 the mean of » observations of y; and 
let E,, and EY be their probable errors, or the limits on either 


side of which there are equal chances of the actual errors, s—a, 

y — 6, being found. Then the probable error of s, E.,, is ex- 

pressed by the formula+ 4 
E? = p° E* + go EY. (14) 

The case of a linear function includes every case in which 
the quantities sought are already approximately known. We 
have only to substitute for these quantities their approximate 
values plus the unknown corrections, and to neglect the squares 
and higher powers of the latter. 

To apply these principles to an important case,—let it be re- 
quired to determine the probable error (or the weight) of the 
mean dip at a given station, as deduced from m, observations, 
with m,; instruments. 


The true dip being equal to the observed dip plus the in- 
strumental correction, it is manifest that, in this case, 


E? = E?,+E%; 


* For the demonstration of these theorems, the reader is referred to a paper 
by Prof. Encke, in the Astronomisches Jahrbuch for the year 1834. See also a 
paper by M. Poisson on the same subject in the Connoissance des Temps, 1827. 

+ See a paper by M. Poisson in the Bulletin Universel des Sciences, tome xiii, 
p. 266. See also the Memoir by Prof. Encke, already referred to, 


ee 
i %" 


MAGNETIC SURVEY OF GREAT BRITAIN. 97 


E,, denoting the error of observation, and E that due to the 
imperfection of instruments. But 


€, denoting the probable error of a single observation, and e,that 
of a single instrument. Hence 


2 
P54 €: 


ee Lai se eeethh, - (15) 

N, n; 
We have here taken no separate account of the error arising 
from the variations of the dip, that error being inseparably 
combined with the error of observation; the symbol é there- 


fore, in the -preceding, denotes the probable error resulting 
from the two conjoint sources. ; 
In order to estimate the value of e,, I have taken the follow- 


ing series of observations, made with the needles, L. 1, L. 4, 
in Dublin, the longest series of observations made with the 
same instrument at a single station in Ireland. The Ist column 
of the table contains the dates of observation; the 2nd the ob- 
served dips (uncorrected); the 3nd the reduced dips, referred 
to the Ist of January, 1836. Inthe 4th column are the differ- 
ences between the partial results and the mean; and in the Sth, 
the squares of these differences. 


Taste XXVIII. 
Needle L. 1. 


Date. Observed Dip. teal Dip. 2a (#—a)* 
4 Lo} 4 

Oct. 21, 1833 70 56-4 70 51-2 — 04 0-16 
Aug. 7, 1834 70 51-6 70 48-2 — 34 | 1156 
ce iS, 70 57°6 70 54:2 4 26 6-76 
=. 9 70 54:3 70 50:9 — 07 49 
= 19, 70 49:5 70 461 —~ 5:5 | 30-25 
Sept. 22, 70 56:0 70 53-0 4 14 1:96 
ao 70 53:8 70 50:8 — 08 64 
Sept. 4, 1835 70 46-7 70 45-9 — 5-7 | 32-49 
= 5, 70 55°6 70 54:8 4+ 32 | 10-24 
ee 70 54-2 70 53-4 4+ 1:8 3-24 
b=) 9, 70 54-4 7) 53-6 4+ 2-0 4-00 
TA, 70 56-7 70 55°9 443 | 18-49 
PETS 70 53°3 70 52:5 4+ 09 81 


VOL. VII. 1838. H 


98 EIGHTH REPORT.—1838. 


Taste XXVIII. Needle L. 4. 


Date, Observed Dip. | Reduced Dip. | w—a™ | (a—a)? 
ce} 4 é 

Sept. 22, 1834. Zi 22 70 59-2 + 91 82-81 
— 23, 70 53:8 70 50-8 + 07 0-49 

— 29, 70 44°8 70 41:8 — 83 | 68:89 

Oct. 25, 70 54-1 70 51:3 + 12 1-44 
Aug. 19, 1835.| 70 51°6 70 503) | + 07 0:49 
Sept. 4, 70 43-6 70 42-8 — 73 | 53°29 
— 5, 70 528 70 52-0 + 19 3°61 

— 7%, 70 52-2 70 51-4 + 13 1-69 

— 9, 70 46-2 70 45-4 — 47 | 22:09 

— i4, 70 53-4 70 52-6 + 25 6°25 

— 15, 70 55-0 70 54-2 + 41 16°81 

Nov. 5, 70 49°6 70 49:2 — 09 0-81 
— 5, 70 45°8 70 45:4 — 47 | 22-09 

— 6, 70 53-9 70 53°5 + 3-4 11-56 

Apr. 1], 1836. 70 481 70 48-9 — 12 1-44 
— 1, 70 47-1 70 47-9 — 22 4:84 

May 7, 70 50:9 70 51:7 + 16 2-56 
— 9, 70 56:4 70 572 | + 71 50°41 

Aug. 5, 70 43:1 70 44:5 — 56 | 31:36 
— 6, 70 51:3 70 52-7 + 26 6°76 


From the former of these tables we find 
n=138, a= 70° 516, 3 (@ — a)? = 121°09; 
and from the latter 
n = 20, a= 70° 501, = (@ — a)? = 389°69. 
Substituting these numbers in (12), the probable error of ob- 
servation in the former series is found to be 21; and in the 
latter 3!-0. 

It is remarkable that the squares of these errors (the inverse 
of which are the measures of the weights) are, almost exactly, 
in the ratio of 1 to 2; that is, in the mverse ratio of the num- 
ber of readings with each needle. This is a curious confirma- 
tion of the accuracy of the conclusion. 

From the preceding it follows, that in combining the results 
of the two needles, L. 1 and L. 4, (when used together) double 
weight must be allowed to the former. It appears from (14) 
that the probable error of the mean, thus deduced, is 18. We 
may therefore consider two minutes as the probable error of 
observation in the present series, whether the result be that 
of a single needle with the usual number of readings, or the 
mean of the two needles L. 1 and L. 4. 

The probable instrumental error, ¢;, varies, of course, within 
very wide limits, depending on the perfection of workmanship. 
In a former part of this memoir, Major Sabine has pointed out 
the very great improvement which our English dipping needles 


MAGNETIC SURVEY OF GREAT BRITAIN. 99 


have undergone in this respect, subsequently to the year 
1835*. The mean error, for any set of needles, may be ob- 
tained from (15), when we have made a series of observations 
with these needles at any one station. Let ¢ denote the pro- 
bable error of the result given by any set of observations with 
a single needle, as inferred from comparison with the others; 
Then ¢ = n, E*, and substituting in (15), we have 


2 


2 i 2 
€*; = e&* —— €> 
| alae n > 


in which the value of ¢@ is deduced from the observations by 
means of (12). 

To deduce, according to these principles, the value of ¢, for. 
the needles employed in the Irish survey, we must compare 
the results obtained at Limerick,—that being the only station 
where all the needles were employed. These resuits are con- 
tained in the following table. The first column contains the 
names of the needles employed ; the second, the dips obtained, 
reduced to the Ist of January, 1837, of which the mean value 
is 71° 0/5; in the 3rd column are the differences of the par- 
tial results and the mean; and in the 4th, the squares of these 


differences. 
Taste XXIX. 


Needle. Dip = 2. @2—a | (@— a) 
8.2 71 26 421 4-41 
M 71 14 40-9 0°81 
Ss. 1+ 70 57:6 — 2:9 8-41 
S.1¢ | 70 591 — 14 1-96 
rt 71 47 +42 17-64 
L. 4 70 57:7 — 28 7°84 


From the last column of the preceding table we find 
> (x — a)? = 41:07; and substituting in (12), e? = 3°70. 


Again, n; = 6, n, = 26, and, assuming ¢, = 2, “ee & = 0°92. 
; n oO 


o 


* The probable instrumental error of the needles employed at Westbourne 
Green in 1835, as deduced from the observations recorded in the Irish Report 
(Fifth Report, p. 142), amounts to 8/3. The mean probable error of the 
needles employed at the same place in 1837 and 1838, as deduced from the 
oe contained in Table III. of the present memoir, is about one minute 
only. 

+ The needle S. 1 had undergone a change in the disposition of its axle in 
the interval between the two observations recorded in this table. These obser- 
vations must therefore (as far at least as the axle is concerned) be regarded as 
the results of different instruments. 

H2 


100 EIGHTH REPORT—1838. 


- We have, therefore, from the preceding formula, ee = 2°78, and 
e, = 17. . 


It appears, then, that the instrumental error is somewhat less 
than the error of observation. The difference, however, is 
probably less than the error of our result ; and we shall as- 
sume, in round numbers, ¢wo minutes as the amount of eacli 
error in the Ivish series. 

Taking, then, e, = ¢, = 2, we have (15) (13) 


1 int 
B= = 4 (7 + ah (16) 


From this formula we learn how useless it is to multiply obser- 
vations with the same instrument, in order to obtain the dip at 
a given station: When n; = 1, we have 


a a4(>+1), <4 x 2; 
w denoting the weight of a single observation ; so that 
Ww 2n, 
wa FT 


and, however the observations be multiplied, the weight of the 
result can never amount to double the weight of a single ob- 
servation. 

in what precedes, we have considered only the actual dip at 
a given station. But in deducing the position of the isoclinal 
lines from observations of dip made at several stations, it is 
necessary to consider likewise the probable difference between 
this dip and that due to the geographical position of the sta- 
tion: or, in other words, the probable mean local error. 

Let ¢ denote this error; then it is manifest, from what has 
been already said, that the actual resulting error will be ex- 
pressed by the formula 


ee eé€ 
eg er (17) 


The mean local error will, of course, be very different in dif- 
ferent countries, the differences depending chiefly on the re- 
lative proportion of the igneous and sedimentary rocks. In 
Scotland, as appears from Major Sabine’s excellent report (Sixth 
Report, p. 102), the local error is considerable; in England it 
is probably small. We may estimate its amount in any district, 
by computing the dip due to the geographical position of each 
station, by the formula (2), and taking the sum of the squares 


. 


mp | 
i" 
a 
> 


of the differences between the computed and observed results. 
This, substituted in (12), will give the total mean probable 
error, or the value of ¢ in the equation (17) (m and n; now 
denoting the mean number of observations, and of instruments, 
at each station); and, «, and e, being already known, we de- 


duce the value of é. 


MAGNETIC SURVEY OF GREAT BRITAIN. 10l 


In addition to the observations of dip already printed in the 
Irish Magnetic Report, the following pages contain, Ist, a se- 
ries of observations made by Robert W. Fox, Esq., at nine 
stations, chiefly in the West of Ireland; 2nd, observations 
made by Major Sabine, chiefly in Limerick; 3rd, my own ob- 
servations in Dublin; and 4th, a series of observations made 
by Captain James Ross, at twelve stations, distributed uni- 
formly over the whole island. 

Mr Fox’s observations are contained in Table XXX. They 
were made in the autumn of the year 1835, at a time when the 
other parts of the Irish survey were in progress; but, Mr. Fox 
not being at that time associated in our labours, his results were 
separately published*. They are now, with his permission, 
republished in the present memoir. The instrument employed 
in these observations has been already described f. 


TaBLeE XXX. 
Mr. Fox’s Observations in 1835. 


Station. Date. Hour. Dip. Place of Observation. 
[eo 7 

Dublin ............ Aug. 17/11 a.m.| 70 59) Garden of Trinity College. 
Galway ....s..e000. — 19} 93 4.m.) 71 26) Hotel Garden. 
Gailhorick......... — 19} 33 p.m.) 71 41] Island in Lough Corrib, 
Clifden ............ — 22) 2p. .| 71 52) Hotel Garden. 
Westport ......... — 24/113 a.m.| 72 3) Garden of Hotel (Sligo Arms). 
Puntoon ......... — 24| 6 vm.) 72 8! West side of Lough Conn. 
Ballina ............ — 25/10 a.m.| 72 7} Hotel Garden. 
Giant’s Causeway] — 27| 44 p.m.| 73 15) East side. 
Cushendall ...... — 28] 914.m.| 72 0} Hotel Garden. 


Major Sabine’s additional observations, contained in Table 
XXXI, were made at Limerick, Dublin, and Bangor, in the 
year 1836. These observations have been already printed 


* Proceedings of the Cornwall Polytechnic Society. 

+ Page 3. : 
_ t With the exception of one set of observations made with Mayer’s needle 
in the year 1833. These observations, though referred tu in the Irish Report, 
were overlooked in the compilation of the tables. 


102 EIGHTH REPORT.—1838. 


in the Scotch Magnetic Report, and are reprinted here, so 
as to have all the data connected with Ireland present in one 
view. The needles employed, (Mayer’s needle and needles 
S.1, S. 2,) have been already described. 


Tasre XXXI. 


Major Sabine’s Observations. 


Station. Date. Hour. Needle. Dip. 
Limerick...} Nov. 1, 1833. 1 pm. Mayer’s. 71 11-0 
«| — 2&4, 1838. 1 pM. 71 11-9 
aes Mean... 71 115 
Limerick...) May 1836. Mayer’s. 
-..| June 
— Mean... 71 00 
.| May 1836. ie | 71 06 
Limerick...| Feb. 20, 1836. 1 em. $2 71 13°4 
Limeriek...| May 5 11 a.m. — 71 13:0 
oe — 5 1 pM. — 71 11:0 
— .. Mean... — 71 12:0 
Dublin ...| July 22, 1836. Noon 71 14:1 
<——, fase] (eee 1 pM. 71 11°6 
—_- ...| — 23 Noon 71 13:7 
ae Mean... 73 71 13-1 
Bangor ...| Sept.21, 1836. 10° am. — 71 48-7 
Dublin ...| Oct. 4 1 pm. — 71 127 


My own additional observations were confined to Dublin, and 
were made in the years 1836 and 1838. The observations of 
the former year, contained in Table XX XIII, were made with 
the statical needles, L. 3 and L. 4, already described. Those 
of the latter, (Table XXXII), with the dip circle, and needle 
G. 2 made by Gambey*; and with another circle of the same 
size, and two needles, made by the same distinguished artist 
for the Dublin Observatory. All these latter observations 
were made according to the method of arbitrary azimuths. In 
conjunction with the observations of Captain Ross in Dublin, 
they are taken as the basis on which the determination of the 
corrections of my other needles, L. 1, L. 3 and L. 4, is made 
to rest, 


* Page 50. 


MAGNETIC SURVEY OF GREAT BRITAIN. 103 


Taste XXXII. 


Mr Lloyd’s Observations in Dublin in 1838. 
Gambey’s Needles.—Method of Arbitrary Azimuths. 


age Azim.* Angle. Azim. Angle. Mean Angle. Dip. 
fe] [e) re U ° ¢ 
8 | 7o4os8 | 180 | 70 560 70 529 } 70 528 
90 | 89 43-4 | 270 | 89 49-4 89 46-4 
10 | 71 41 | 190 | 71 116 7 7:8 } 70 526 
100 | 86422 | 280 | 86 372 86 39-7 
x | 90 | 71540 | 200 | 71591 71 56-5 70560 
= | 10 | 83330 | 290 | 83 21-9 83 27-5 } 
ES iiaee| (7a | 210 |: 73 194 73 15-4 \ aricey 
~ | 120 | 8027-4 | 300 | 80 139 80 20-6 
> | 40 | 75 09 | 220 | 75 40 75 25 70 551 
th | 130 | 77402 | 310 | 77 82-4 77 363 } 
< | 50| 77204 | 23 77 24-0 77 22-2 nd HHS 
| M0 | 75179 | 820 7 M1 79 145 } 
60 | 80 10 | 240 | 80 8 0 48 
© | 50] 73280 | 330 | 73200 | 73 240 } area 
70 | $3 44 | 250 | 83 85 83 65 70 BBA 
160 | 72 64 | 340 | 71 591 72 23 
30 | 86165 | 260 | 86 23-0 86 19-8 70°82 
170 | 71148 | 350 | 71 71 71 11-0 } 
-| o| 70591 | 180 | 71 19 71 05 ; 
S| 99 | 89535 | 270 | 89523 | 89 52-9 } 71 0S 
Sei, 30 | 731i | 210 |...78 195 3.153 70 SEF 
a% | 120 | 80162 | 300 | 80 11-0 80 ise 
& | 60 | 80 96 | 240 | 80 169 80 13°3 Wea 
21150 | 73207 | 330 | 73 17-1 73 18-9 } 
-| 0 | 70559 | 1890 | 71 17 70 58:8 
&| 90 | 89512 | 270 | 89530 | 89 521 } 05a 
ax | 39 | 73 161 | 210 | 73 291 73 22-6 Hi bho 
dt | 120 | 80220 | 300 | 80 68 80 14-4 } 
=| Go| 80160 | 240 | 80 249 80 20-5 page 
® | 150 | 73267 | 330 | 73 195 73 23-1 } js 
wt| 71260 | 195 | 713826 71 29°3 Loeee 
ei | 105 | 85 19-4 | 285 | 85 13-4 85 ie f 
eat | 45 | 75539 | 225 | 75 59-4 75 56-6 ee 
Gu | 135 | 76336 | 315 | 76 30-4 76 32-0 } 
75 | 94983 | 255 | 84 31-1 84 29-7 70 59-9 
165.| 71467 | 345 | 71 38:1 71 42-4 


* The Azimuth 0? is the magnetic meridian, the face of the instrument being to 
the cast. The azimuths increase in the order N., E., S., W 

+ The azimuths in this last observation are set down in a round number of de- 
grees. They were (exactly) 14° 19’, 44° 15’, 74° 15’, &c. 


Be et oe) 


104 EIGHTH REPORT—1838, 


TasLe XXXII. « 
Mr. Lloyd’s Observations in Dublin in 1836. 


Needle L. 3, Needle L, 4. 

Date Hour. 

ME abos| ks es tell Cnr rres 
April, 11. 12 18 
— I5. 12 30 
Mean... 12 24 
May 7. 1 32 
— 9. 1 25 
Mean... 1 28 
Aug. 5. 3 50 
— 6. 2 35 
Mean... 3 12 


The observations of Captain Ross were made in October and 
November, 1838, with the needles designated as R. 4, R. 5, 
R. 6, R. 7, L. 3, L. 4, in the preceding pages. The stations 
of observation being sufficiently numerous, as well as uniformly 
distributed, it has been thought advisable to combine them in a 
separate determination. ‘The observations are contained in 
Tables XX XIX. and XL. 

We have now to consider the actual errors of the instru- 
ments employed in the preceding observations. 

The errors of dipping needles may be ascribed to one or 
other of the three following causes: namely, 1, the friction of 
the axle on its supports; 2, the imperfect curvature of the 
axle itself; 3, magnetism in the limb. 

It is owing to the first-mentioned cause that a dipping nee- 
dle assumes, in general, a new position of equilibrium after it 
has been disturbed, the limit of error being the angle at which 
the directive force, increasing as the sine of the deviation, 
becomes equal to the friction. This limit varies, for a given 
state of polish of the axle and of its supports, with the radius 
of the cylindrical axle, the weight of the needle, and its direct- 
ive force*. In all the earlier dipping needles constructed in 
this country, this limit of error is considerable, owing to the 
unnecessary size of the axle. 

The errors arising from the two latter causes are, however, 
of a very different nature. The positive and negative errors 
due to friction are equally probable, and the effect of the dis- 


* Trans. Royal Irish Academy. Vol. xvii. p. 166. 


MAGNETIC SURVEY OF GREAT BRITAIN. 105 


turbing cause is merely to widen the limits of probable error. 
The imperfect curvature of the axle, and the magnetism of the 
limb, act however very differently. Either of these sources of 
error must, at a given place, affect all the results in the same 
manner; and, consequently, no repetition of observation, with 
an instrument so circumstanced, can afford even an approxi- 
mation to the true dip. At different places the error will be 
different, and will vary according to no assignable law. 

The course to be pursued by the observer with reference 
to these errors is manifest. Their existence or non-existence 
should be ascertained at the outset by one or other of the means 
pointed out by Major Sabine in the commencement of this me- 
moir; and if found to surpass certain limits, the instrument 
should be rejected. The case is different, however, when the 
instrument has been actually employed for some time pre- 
viously to the detection of the error. Here we must seek, if 
possible, to determine the probable amount of the error, and 
apply it, with an opposite sign, as a correction to the results. 
Where the district of observation is limited, this is practicable. 
It will be easily understood, that the imperfect curvature of the 
axle, or the disturbing action of the limb, must, within a moderate 
range of dip, affect all the results in the same manner, so that 
they will all require a correction having the same sign; and that 
when the range of dip is very small, the amount of the dis- 
turbance will be nearly the same throughout, and consequently 
the correction required will be nearly constant. In such a case 
then we have only to determine the amount of the error at some 
one station, by a comparison of the results with those of proved 
needles obtained at the same place, and, if possible, at the same 
time. 

Again, in needles whose poles are unchanged, gravity acts 
with a certain moment with or against the directive force; the 
coincidence of the centre of gravity with the axle being rarely 
attained. The observed inclination, therefore, deviates from 
the true dip, and the amount of this deviation varies in different 
places, according to a known law*. To obtain its actual 
value, however, at any station, it must be known at some one; 
and this knowledge is to be obtained, as before, by a com- 
parison of the results with those of other needles at that sta- 


\ 


* Fifth Report, p. 144. With needles whose poles are inverted in each 
observation, the true dip may be inferred from the observed angles of incli- 
nation, however considerably they may deviate from it. In such needles, 
therefore, the non-coincidence of the centre of gravity with the axle cannot 
properly be ranked among the sources of error. 


106 EIGHTH REPORT—1838. 


tion. When the district of observation is limited, the vari- 
ation of this quantity may be disregarded.” 

The importance of an exact determination of these needle- 
corrections is very great in the present instance. When, in- 
deed, the same needle is employed throughout an entire series 
of observations (as was done by Major Sabine in Scotland), it 
is manifest that any error in the amount of its correction will 
have the effect only of displacing the isoclinal lines in absolute 
position, leaving their direction and interval unaltered. For 
the direction and interval of the lines depend solely on the déf- 
ferences of dip; and these are manifestly independent of the 
correction, which alters all the dips by the same amount. The 
case is different, however, when (as in the present instance) 
different needles requiring correction are employed in the same 
series. Here the differences of dip cannot be known, unless 
we know the differences of the corrections of the needles em- 
ployed ; and it is manifest that any error in the amount of that 
difference will displace one entire group of results relatively to 
the rest, and thus (when the mean geographical position of 
these groups is different) induce a grave error in the direction 
of the lines. 

Before we proceed to determine the amount of these errors 
in the needles employed in the Irish survey, it may be desirable 
to make a few remarks on ¢heér particular causes. 


Of the two sources of error above mentioned, the amperfec- 


tion of axle appears to be the most common; and it is to it we 
are to ascribe (as Major Sabine has already remarked*) the 
chief part of the discordances in the results obtained at West- 
bourne Green in 1835. The same series, however, affords like- 
wise a remarkable instance of the other error. Having pur- 
posely destroyed the balance in two of my dipping needles, so 
that they rested nearly in the horizontal position in Dublin, I 
proceeded to use them exclusively for observations of intensity. 
The results thus obtained were, however, so anomalous, that I 
was compelled to reject them altogether. After some tedious 
and vain attempts to discover the source of the anomaly, I was 
at length satisfied, by a careful inspection of the results, that the 
needles were under the influence of some other force besides 
the earth’s magnetism and gravity, and I concluded that this 
disturbing force could be no other than magnetism in the dip 
circle itself. ‘Trial soon verified this conjecture, and I had the 
mortification to find that the apparatus which I had been so 
long using was throughout magnetic, and that the magnetismt 


* Page 46. 
+ Magnetism induced in ferruginous matter, not permanent. 


‘Sat ad 


MAGNETIC SURVEY OF GREAT BRITAIN. 107 


was greatest in the graduated limb, the very part in which, from 
its proximity to the needle, it must operate most powerfully. 

Thad next to consider the painful question,—How far the nu- 
merous results obtained with this instrument were vitiated by 
this newly-discovered source of error? Whether they were 
entitled to any confidence; and if so, what were the probable 
limits of error? It is manifest that if the ferruginous matter 
were uniformly distributed throughout the limb, it could pro- 
duce no disturbance in the position of a needle which (like the 
dipping needle) divides the limb symmetrically. It is only by 
an irregularity in its distribution that the magnetic matter of 
the limb can operate as a disturbing cause; and then it is ma- 
_nifestly only by the difference of the attractions, on the two 
sides of each pole, that the needle is actually disturbed. Hence, 
though the magnetism of the limb may produce very decided 
_ effects upon a test needle, in a position at right angles to its 
plane, the effect upon a dipping needle may be comparatively 
trifling. 

In order to estimate the amount of these effects, I separated 
the divided circle from the apparatus, and placed it on a hori- 
zontal support of wood. ‘Three strong pins in contact with the 
inner edce of the limb, and dividing it equally, were then driven 
into the support, so as to prevent the limb from having any 
motion, except one of rotation in its own plane. A magnetic 
bar, whese length was nearly equal to the diameter of the circle, 
was then supported delicately within it, and the deviation of 
_ the bar from its undisturbed position was observed in the 
different positions of the limb with respect to it. It was thus 
found that most parts of the limb exerted a sensible disturbing 
‘effect upon the needle ; and that this effect was not only con- 
‘siderable in the neighbourhood of the two zero points of the limb 
(the part where the anomalies had been first observed), but that 
it also varied there very rapidly. A detailed examination of 
the effects in this position showed that there was a disturbing 
‘centre of ferruginous matter in the neighbourhood of each of 
these points, and that it was to the action of these centres 
‘that the anomalies in the observations above alluded to were 
owing. 

. fathe neighbourhood of the divisions of 70° the disturbance 
‘of the needle was likewise considerable, and its direction was 
‘such as to diminish the apparent dip. Here, then, we have the 
cause of the large negative error of the results obtained with 
this instrument. But this deflection did not vary rapidly on 
either side of these positions, so that for small changes of dip 


108 EIGHTH REPORT—1838. 


the error may be regarded as nearly constant*. Defective, 
therefore, as the apparatus is in this respect, there is reason to 
conclude that the differences of dip obtained with it in Ireland 
may be relied on within the usual limits of probable error, and 
that to obtain the true dip from the observed results, we have 
only to apply a posttive correction, which may be regarded as 
constant throughout the series. 

The instrument referred to in the preceding pages having 
been much employed in Dublin, and with very consistent re- 
sults, we shall take, as the basis of its correction, the dip in 
Dublin as deduced from the observations with Gambey’s nee- 
dles, Table XXXII. In these observations, made according 
to the method of arbitrary azimuths, the bearing points of the 
axle, and the position of the needle with respect to the limb, 
are different in each azimuth; so that the results may be re- 
garded as, virtually, the results of different instruments. 
Their accordance is sufficient to show that the errors of axle 
and of limb are inconsiderable. For the convenience of refe- 
rence, the observations are put together in the following Table ; 
the dips being reduced to the Ist of January, 1838. 


TaBLE XXXIV. 


Needle. Azimuth. Dip. Needle. Azimuth, Dip. 

ov o ° xo) ‘ o q ° ° o. 4 

6 #, 0& 90} 70542 |] S32 | 0& 90) 71 23 
38 10 & 100 | 70 54-0 23 5 5 }| 308 120| 70 54:5 
a? 20& 110] 7057-4 || BAR 60 & 150 | 70 57-4 
ZS | 30&120| 70 57-4 ois (|, O& 90| 71 O6 
~AMe | 40&130| 70565 || os || 15&105| 71 Ol 
ome | 50&140| 70 567 | > m8 2 30 & 120} 71 11 
Ss 60& 150 | 7057-4 || 3.29 G)| 45&135| 70 553 
ES 70& 160 | 70568 || £2 || 60& 150] 71 43 
tS 80&170| 70 540 | 54 UL} 75 & 165 | 71 17 


The mean of these results is 70° 579. If we combine with 
this the mean result obtained by Captain Ross at the same 
place, as deduced from six observations with four needles, and 
reduced to the same epoch, (namely, 71° 1':7,) we have, for 
the mean dip in Dublin, on the Ist of January, 1838, 


70° 58'-8. 
* A comparison of the results with those of other instruments seems to point 


to the conclusion that this error diminishes with the dip, and is somewhat less 
in England than in Ireland. 


MAGNETIC SURVEY OF GREAT BRITAIN. 109° 


To compare with this, we have the following observations 
with the needles L. 1, L. 3, L. 4, in Dublin, 


TaBLE XXXY. 


Needle. | No. Date. Observed Dip. | Reduced Dip. Mean Dip. 
{e) 4 (e) 

L1 | 1 | Oct. 21,1888 | 70 56-4 70 46-4 aed 
—_— 6 Aug. 25, 1834 70 53-8 70 45:8 70 46:8 
—_ 6 Sept. 9, 1835 70 53:5 70 47-9 

L3 4 Apr. 25, 1836 79 57-7 70 53-7 70 53°5 
— 2 Aug. 5, 1836 70 56-5 70 53-1 } 

L4 4 Oct. 2, 18384 70 53-7 70 45:9 
_ 7 Sept. 6, 1835 70 50-7 70 45:1 
—_— 3 Noy. 5, 18385 70 49-8 70 44°6 70 45°4 
— 4 Apr. 25, 1836 70 50°6 70 46°6 
— 2 Aug. 5, 1836 70 47-2 70 43:8 


Hence we obtain the following corrections : 


Needle L. 1, correction = + 12'0 
” L. 3 ” = 5-3 
pe AA its = + 13!-4 


In L. 3 and L. 4, needles whose poles are unchanged, the 
errors here deduced are, of course, those which result from 
the moment of the needles’ weight, combined with that arising 
from the disturbing action of the limb. 

The weights due to these corrections are at once deduced 
from the principles of the preceding pages. When the results 
of one needle, at a given station, are compared with those of 
others, and that we seek their difference, it is manifest that 
p=1,q=1, (14), and that, consequently, 


B= BY + EY; 


KE, denoting the probable error of the mean result of the 
given needle, and E, that of those with which it is compared. 
When we look no further than the actual difference of the re- 
‘sults at the one station, it is manifest that 


€, and ¢, denoting the probable errors of a single observation, 
in the needles compared, and m, and n, the number of obser- 


110 EIGHTH REPORT—1838. 


vations. Hence, if ¢, = ¢€,, that is, if the reading power be 
the same in the two cases, and the same pains be bestowed on 
the observations, 


—— == — obs (18) 


2 , 
nm denoting the value of the ratio a or the equivalent num- 


ber of observations of the difference sought, supposing it to be 
the immediate subject of observation. 

But when we desire to compare the result of the uncor- 
rected needle with the actual dip, we must also take into ac- 
count the probable instrumental error of the results with 
which it has been compared ; and we have (15) 


oh Lira bei AM (19) 
n nN y 


To apply this, we shall assume, as before, the instrumental 
error to be equal to the error of observation, the latter inclu- 
ding the error of epoch ; and we obtain 


Needle L. 1, n, = 13, » = 61, 
— L.3, —— 6, —— 39, 
— L.4, — —20, ——73. 


We shall adopt the nearest whole numbers, 6, 4, 7. 

The correction of needle S. 2 has been determined with 
great care by Major Sabine*, by a comparison, at various sta- 
tions, of its results with those of the needles M and G. 2, 
needles which may be regarded as almost free from all instru- 
mental error. The amount of this correction is — 9°6; and 
its weight 16. This amount is almost identical with that pre- 
viously employed in the calculation of the Irish observations. 

The other needle employed by Major Sabine in Ireland, S. 1, 
is constructed on a plan suggested by Mr. Dollond. The 
middle of the needle has the form of a cube, and is perforated 
so as to receive the axle in different directions, the intention 
being, that the position of the axle should be varied in the 


* Table XIX, 


MAGNETIC SURVEY OF GREAT BRITAIN. lll 


course of every observation. From some defect of workman- 
ship, however, the balance of the needle was much deranged 
in some positions of the axle; and it was accordingly employed 
by Major Sabine as an ordinary dipping needle, the axle being 
permanently fixed in one position in which the needle was to- 
lerably balanced. ‘This was the case during the observations 
made with it in August, September, and October, 1834 (Fifth 
Report, p. 139); the axle being undisturbed during the whole 
of the series. In 1835, when Captain Ross used this needle 
at Westbourne Green, the axle had been repolished, and was, 
moreover, fixed by the artist in a different position from that 
which it had occupied during the observations of the preceding 
year. So far, therefore, as axle error is concerned, the needle 
ag then and thenceforward, be regarded as a different nee- 
dle. 

In order to deduce the amount of the axle error, previously 
to the alteration just alluded to, we may compare the result 
obtained with this needle at Limerick, in August 1834, with 
the mean dip of the place as given by other needles. The dif- 
ference (4/:2) is probably not greater than the probable error 
of observation, which, owing to the imperfect polish of the 
axle, was in this needle considerable. Under these circum- 
stances, we are not justified in assigning to it any correction. 

The needles employed by Mr. Fox appear to give results 

_ extremely consistent with one another, and with those of other 
needles. In their case, therefore, no correction is required. 

We are now prepared to exhibit in one view the mean* 
values of the dip, as deduced from these various needles. 'The 
following table contains the results of observations arranged 

chronologically, and corrected as has been above explained. 


* Where the needles L. 1 and L. 4 have been employed together, double 
weight has been allowed to the results of the former in taking the mean, in 
accordance with the conclusion of page 98. 


112 EIGHTH REPORT—1838. 


Taste XXXVI. 


Corrected Dip. 


Station. Date. Needle. | No. Dip. Mean Dip. 
Dublin sae Oct.21, 1838] L.1 {1/71 84 |71 84] | 
Limerick ......... Nov. 1833} M |4/71117 | 71117 ' 
Limerick ......... July, 1834) L.1 | 5 | 71 11:5 71 (11°5 ; 
Dublin ............ Aug. Sept L.1l | 6| 71 58 71 61 
Sept. Oct L4 |4/71 71 
Limerick’ J..ccsss Aug. 1, 16 S.1-| 2] 71 35 71 35 
Glengariff......... Sept. 27, 28 SSG 02) lig bd 71 = 15 i 
Killarney ......... Oct. 4 S.1 | 1/71 45 | 71 45 
Wallace. — 12 s.1 | 1] 71158 | 71 15:8 ¢ 
Carlingford ....... — 13 L.1 | 1 | 71 283 71 302 + 
ae L.4 |1| 71 34-0 ; 
Armagh ......... — 14,15 L.1 | 2 | 71 48:5 fi 
os Gahas L.4|2] 71 307} 7) 4a 
Colerain .........| — 20 L.1 | 1 | 71 27:6 
— 20 T4814 9a 35-6 71 26-9 : 
Cam iveccasonas-=2- — 21 L.1 | 1 | 71 59°8 ; 
Ege L.4 +7 (72 30 12 09 ‘ 
Strabane ....+.... — 23 L.1 | 1) 72 36 , g 
— 23 Be G) bli sash 72 00 e 
Enniskillen .......| Oct. 24 1834, L.1 | 1)|72 00 72 0-0 4 
Fermoy ....++++e++- Dec. 2 L.1 | 1 | 70 48:3 70 48:3 
Limerick July, 1835} S.2 |4|71 73 71 73 
Dublin .........+. Aug. 17 F 70 59:0 | 70 59-0 
Galway ...+e+eesees — 19 F 71 26:0 71 26:0 
Gallhorick......... — 19 F 71 41:0 71 41:0 
(On 6 Eas — 22 F 71 52-0 71 52-0 
Westport ......... — 24 F 72 3:0 72 3:0 
Puntoon ......... F 72 80 72 80 
Ballina ............ — 25 F 72 70 | 72 7:0 
Giants Causeway| — 27 F 73 15:0 | 73 15°0 
Cushendall ...... — 28 F 72 0:0 72 0:0 
Markree ......... — 21 L.1 | 2) 72 56 72 63 
— 21 L.4 | 1/72 90 
Ballina ....... woe | — 22 L.1 | 1 | 72 13:9 ‘ 
— 22 L.4 |1| 72 33 72 110 
Belmullet ......... — 24 L.1 | 1 | 72 14:7 
er L.4 | 1] 72 109 t (2384 
AChU iisccssecese — 2 L.1l | 1] 72 64 
aT L.4 |1]| 72 eat bell 
Galactic oes — 28 L.1 | 1] 71 33-9 
J ay LéAiehn 308 f iLa79 


MAGNETIC SURVEY OF GREAT BRITAIN. 113 


Station. Date. Needle. | No. Dip. Mean Dip, 
Ennis. .....ccseees Aug, 28 L.1 1 | 71 1355 
98 L.4 |1) 711255 | 7) 182 
Limerick ......... — 29 L.1 1/71 39 7Y 2-9 
— 29 Fede sonia a a rk. 
MEO ER accaccawexses — 31 L.1 | 1} 70 41:3 : 
are L.4 |1| 704665 | 7° 434 
Waterford......... Sept. 1 L.1 1 | 70 49°6 
= L.4 |1| 70 52:2¢ | 79 905 
Broadway ......... — 2 L.1 1 | 70 31-4 
‘ ig L.4 |1| 70 45-0f | 79.359 
Gorey  ..sceeeeeeee — 3 L.1 1 | 70 55-4 
7 og L.4 |1| 70565 / | 70 958 
Rathdrum......... — 38 L.1 1 | 70 53°1- 
Tae L.4 |1]| 70 349 f 70 535 
Dublin .......0.0+. Sept. 4—15 L.1 |6| 71 ae Neel 
— Aug. Sept. L4 |7)71 41 ? 
Nov. 5, 6 L.4 3/71 32 71 32 
: Ballybunan ...... — 8 S. 2 1 | 71 195 71 19:5 
J Valentia —1 12 S. 2 1|71 5:4 71 54 
Dingle .... — 18 S. 2 1|71 81 71 81 
Tulla....... Dec. 10 8.2 | 1 | 71 269 71 26-9 
Limerick — 26, 27 8.2 |3]71. 50 71 5:0 
Youghal — 29 S. 2 2 | 70 39°4 70 39-4 
Limerick Feb. 18386} 8S. 2 1/71 38 71 38 
Sree May S.2 |2|71 24 
— May Ss. 1 1/71 O06 71 sil 
May, June M 2/71 00 
Dublin ............ April, May L.3 4/71 30 71 35 
April, May L.4 |41|71 ‘of ? 
— July 22, 23 S. 2 3) 71 35 71 35 
—— Aug. 5, 6 L.3.h2: |, 70g Ui elbeaeauy 
Aug. 5, 6 L.4“|9 P71 ost 
Bangor ............ Sept.21 S.2 | 1 | 71 3971 71 39-1 
Dublin ............ Oct. 4 8.2 1|71 31 71 31 
- Aug. 3—7, 1838} G.2 | 9 | 70 546 70 54:6 
— Sept. 25, 26 D.1 3 | 70 563 79 57-9 
— Sept. 27— Oct. 2 D.2 6 | 70 58:7 


VOL. vil. 1838. I 


114 EIGHTH REPORT—1838. 


The following table contains the final mean dip at each sta- 
tion, reduced to a common epoch, (the Ist January, 1837,) ; and 
the latitudes and longitudes of the stations : 


TaBLE XXXVII. 


Station. Lat. Long. Dip. Station. Lat. Long. Dip. 
| 
Z tf ‘ 
Causeway .| 55 15 | 631 | 73 11°8 || Colerain ...| 55 8| 6 40 | 71 21°6 
Belmullet .| 54 13 | 9 57 | 72 10-2 || Tulla ...... 52 52 | 8 43 | 71 17-5 
Ballina ...) 54 7|9 7 | 72 5°8 || Ballybunan| 52 30| 9 41 | 71 168 
Puntoon ...| 53 58 | 9 10 | 72 4:8 || Ennis ...... 52 51 | 8 58 | 71 10:0 
Markree ...| 54 12 | 8 26 | 72 3:1 || Dingle...... 52 8/1017] 71 5-4 
Achill ...... 53 56| 9 52 | 72 3:3 || Valentia .... 5156 | 1017] 71 27 
Westport...| 53 48 | 9 29 | 71 59-8 || Limerick...| 52 40 | 8 35 | 71 18 
Cushendall} 55 4/6 5 | 71 568 || Dublin ...| 53 21 | 616] 71 12 
CartGesse.. 55 15 | 7 15 | 71 556 || Killarney || 52 3] 9 381 | 70 59-1 
Enniskillen| 54 21 | 7 38 | 71 54:8 Glengariff .| 51 45 9 31 | 70 56-1 
Strabane ...| 54 49 | 7 28 | 71 54:8 Gorey ...... 52 40 6 17 | 70 52°6 
Clifden ...| 53 29 | 9 59 | 71 488 || Rathdrum | 52 55 | 6 14 | 70 50:3 
Bangor ...| 54 39 | 5 42 | 71 38-5 || Waterford | 5216 | 7 8 | 70 47:3 
Gallhorich.| 53 25 | 9 5 | 71 37:8 || Fermoy 52 7| 8 16 | 70 48:3 
Armagh ...| 54 21 | 6 39 | 71 36-9 || Cork ...... 51 54 | 8 26 | 70 39-9 
Galway ...| 53 17|9 4 | 71 263 || Youghal...| 51 57 | 7 50 | 70 37-0 
Carlingford] 54 2 6 11 | 71 25:0 || Broadway | 52 13 | 6 24 | 70 32-7 


Of the foregoing results, those obtained at the Giants’ Cause- 
way and at Colerain are manifestly affected, to a very consider- 
able extent, by the disturbing action of the basaltic rocks. The 
effect of the basaltic pillars of the Causeway upon the magnetic 
needle has been long since observed ; and on comparing the dip 
recorded in the preceding table, with that due to the geogra- 
phical position of the station, we find it in excess to the amount 
of 50’. At Colerain, on the other hand, the effect of the 
disturbing action has been to diminish the dip, but in a less 
amount. The cause of these irregularities being apparent, we 
have no hesitation in rejecting the results, in the computation 
of the the isoclinal lines. 

Before we proceed to this computation, we must estimate the 
weights of the observed results ; and for this purpose it is ne- 
cessary to know the amount of the probable error of station. 
This is obtained by computing (with assumed approximate 
values of L,M,N,) the probable dip at each station, due to its 
geographical position, and comparing it with that observed. 
The sum of the squares of the differences of the computed and 
observed results, substituted in (12), will give the total mean 
probable error ; from which (the errors of observation and of 
instrument being already known) the local error is deduced 
by means of the equation (17). 


MAGNETIC SURVEY OF GREAT BRITAIN. 115 


Now assuming the approximate values 
L = 71° 225, M= +'30, N= +°51; 
the probable dip at each station will be given by the formula 
2 = 71° 22-5 +°30 2 4°51 y; 

and the computation gives for the sum of the squares of the 
differences of the computed and observed results, at the 32 
stations, 

> (vw — a)? = 119209; 
from which we find (12) 

EB? = 17°48, Ee = 42, 
E denoting the total probable error at any one station. But if 
E and E, denote the mean probable errors of observation and 
of instrument at each station, and E, the probable local error, 


EK? = Ee + E} + Ej, 
For the observations of this series, Ej = E,= 2:0* ; wherefore 
E, = Bela 
To deduce the weight of the result of », observations, with n; 
instruments, at any station, we substitute the values thus ob- 


_ tained in (17), and we obtain 


When the local error, therefore, bears so great a proportion to 
the errors of observation and of instrument, as it does in the pre- 
sent instance, it is manifestly waste of labour (as far as regards 
the determination of the position of the isoclinal lines) to mul- 
tiply observations at any one station. In the case under con- 
sideration, the weight due to the result at any station (however 
the observations be multiplied, and whatever the number of in- 
struments employed) can never amount to double the weight of 
a single observation. 

Substituting the values of , and m, in the preceding formula, 


we find the weight of the mean dip, in Dublin and Limerick, 
equal to 1°8, the weight of a single observation being unity: in 
no other case throughout this series does the weight amount 
to more than 1‘°3. Taking the nearest whole numbers for the 
value of this ratio, we shall assign a weight of 2 to Dublin and 


* Throughout a considerable portion of the series, two needles, T.. 1 and L. 4, 
were used together. The probable error of observation of the mean is nearly 
2'; the instrumental error is little less than that of a single needle, being, in this 
case, due chiefly to the magnetism of the limb. 

12 


116 EIGHTH REPORT—1838. 


to Limerick, the weight of each of the other stations being unity. 
The results of the calculation are the following : 
L = 71° 22-74, M = +:'300, N = +°505. ; 
a= — 59° 16, r =°587. t 
Accordingly, the dip at the central station (latitude = 53° 21’, 
longitude = 8° 0') is 71° 22/7; the epoch being the Ist Ja- 
nuary, 1837. 


Captain Ross’s Observations of Dip in Ireland. 


These observations were made at 12 stations, with the needles 
already designated as R.4, R. 5, R. 6, R. 7, They are con- 
tained in the following table. 


TasLeE XXXVIII. 


3 
b=! Poles. 
: s +. Observed < Place of 
$s 5 . $ A beervati 
tation Hour, 9S qeayesea . Dip. Mean Dip. Observation. 


Waterford .... 1-0 P.M.) R 6) 2 70 43-4 


Oo ‘ 
B 70 50-4) 70 469)] , , 
3:15p.M.| R 4\a 70 44:3 0 45°8'In an Orchard, 
B 70 45°1\ 70 44:7 4 mile mag. S. 
@urkrsescescanes 1-45p.m.| R 6|« 70 36°6 of the Church. 
B70 42 |70 393 
3°20p.M.| R 4) a 70 34:5 
B 70 38:3) 70 36-4 
2-15p.M.| R 7\a 70 41°77 70 39:4\In Mr. Jones’s| 
B 70 41°7| 70 41:7 nursery grounds. 
3:30p.M.| R 5) a 70 36°6 j 
B 70 43-4|70 40 
Valentia Is- 2:30e.M.| R 6) a 70 50-2 
land. B 70 54:4) 70 523 
1:0 p.m.) R 4/2 70 515 fr 
B 70 52-1|70 51-8| $70 52 |Near the N. W.| 
2°30p.m.|R 5) 70 50-2 point of the} 
B 70 53-6) 70 51-9 Island. 
Killarney...... 1:30e.m.! R 6| 2 70 49:3 
B 70 55:9| 70 52-6 
11°204.M.| R 4) 2 70 49°6 i 
B 70 49-6|70 49:6) - 70 51-1\In the grounds 
3:0 p.m.| R 5) 2 70 50:2 of Mucruss,near] — 
B 70 53-6) 70 51:9 the Abbey, the} 
Limerick...... 2-30P.M.| R 6|@ 70 58-2 demesne of H. 
B71 18/71 0 }) Arthur Herbert, 
4:0 rm. R 4\e¢ 70 58-4 Esq. 
B 70 58-4|70 58-4 
10 p.m.|R 5)¢ 71 1 70 59:6 In the garden o} 
B 70 59-7|\71 O04 Somerville, the 
2-45 p.m.) R 7| a 70 59-7 seat of James’ 
B 70 59-6) 70 59-6 Hervey, Esq. 
Shannon Har- 11-204.m.| R 6) e 71 19 
bour. B 71 25-4171 22-2 
1:0 p.u.|R 4) 71 25°5 71 23-2\In the garden o 
B71 22°7\71 24:1 Faulkner's Inn. 


MAGNETIC SURVEY OF GREAT BRITAIN. 117 


s Poles. 
Station. Date. Hour. E geet. On ed! Mean Dip. Pritt oh Zh 
: 1838. SAW 
|Dublin........., Oct. 29) 1:0 p.m.) R 6}% 70 58:2) | | 
: B71 42/71 1-2 
2:0 p.m.| R 7| a 70 59-4) | 
B71 1-471 0-4 
2-45p.m.| R 4) a 70 59°8 
B71 02/71 O Bie we 
4-0 p.m.) R 5) 70 566 70 59°8)Near the Mag- 
B71 0:8) 70 58-7 netic Observa- 
— 30} Noon /|R 6)a 70 57 tory in the Gar- 
B71 1:3)70 59-1 dens of Trinity 
1:30e.m.) R 4) @ 70 57:8 College. 
B71 0°6)70 59-2) J 
Armagh.......| Nov. 2 {11:0 a.m.) R 6) @ 71 38-4 
B 71 42-4)71 40-4 
0:30P.M.) R 4) a 71 39°7 
B 71 40:3) 71 40 71 40:5/In_ the garden 
2:20p.m.|R 5} 71 41:1] North of the 
B71 41 {71 41:1 Observatory. 
Londonderry.| — 5 | 1:30p.m.)R 4)a 72 4:7 
B72 0:5/72 2-6 
40 p.m.) R 6)2 72 2°6 . 
B72 3:7|72 3:2) >72 2-3\In an orchard, 
— 6 2:30PM.) R 5)@ 72 17 S.W. by S. true 
B72 O7|72 1:2 14 a mile from 
Sligo.........0. — 10) 0-40r.m.)R 6)2 72 0 the Cathedral. 
B72 06/72 03 
2°30pe.m.|R 4)«¢ 72 2-2 72 (0-2\In the grounds o! 
B71 58-2)72 0-2 ineaomeme cent 
Westport...... — 13] 1:30p.m.) R 6) 71 57°8 J. Cooper, Esq., 
B 71 58:8) 71 58-3 M.P. 
} 3'10pP.m.) R 4|)e 72 1:0 71 59 |In the garden o 
B 71 58-4] 71 59-7 the Hotel. 
Edgeworths- | — 19) 1-15p.m.) R 6) 71 27:6 
| town. B 71 32:6|71 30-1 
3:15p.m.| R 4) 71 29:2 71 29-8\In the garden o: 
B 71 29-9) 71 29°6 the residence o 


The next table contains the latitudes and longitudes of 
Captain Ross’s Irish stations, and the mean dip at each station. 
The observations were made in such quick succession that the 
‘reduction to a mean epoch is unnecessary. 


wt? TaBLeE XXXIX. 


Station. Lat, | Long.| Dip. Station. 
Ae tee: : 

mdonderry........ 55 0 J 80 72 62-3||Dublin.........000 
Markree.............. 54 12] 8 26 72 00-2||Limerick............ 
Westport..........0. 53 48] 9 29,71 59 ||Valentia............ 
Armagh.............. 54 21) 6 39) 71 40-5)|Killarney............ 
Edgeworth’s-town |53 42| 7 33|71 29-8||Waterford........... 
Shannon Harbour |53 14| 7 52) 71 23-2|\Cork. .........se0000. 51 54| 8 


ee ee ee ee eee Ee 


118 EIGHTH REPORT—1838. 


The foregoing observations having been made with diferent 
needles in the same circle, it becomes necessary, in estimating 
the probable error, to separate those due to the limb from those 
which arise from irregularities in the axle. From the mode in 
which the observations were taken,—namely (in all but one in- 
stance) a single observation with each needle,—the azle error 
and the error of observation are combined ; and the beautiful - 
accordance of the partial observations shows that their com- 
bined result is inconsiderable. There seems reason, however, 
for believing that the circle itself is not free from error. The 
mean result obtained with these needles, in this circle, at West- 
bourne Green, is 20 Jess than the mean of the other needles 
employed at the same place (see Table III.) ; while on the other 
hand, they give a result 38 in excess of the mean dip, as shown 
by Gambey’s needles in Dublin,—the latter being observed by 
the method of arbitrary azimuths. 

Now the total probable error at each station, in this series, 
(as deduced from a comparison of the computed and observed 
results) is found to be 4/:0,—a result scarcely differing from 
that of the former series. Of this, the part which is reduced 
by repetition is (as has been already stated) exceedingly small ; 
and, consequently, the remainder (the combined result of the 
station and circle errors) is considerable. Under these cir- 
cumstances, it will be readily seen, no disproportion in the 
number of observations can materially alter the weights; and 
as, in addition to this, the observations have been distributed 
with some attention to uniformity, it is manifest that we must 
regard the weights of all the stations as equal. 

The results of calculation are 


div '71° 22-08 Nie 42-270, * No -4- -550 
wu = — 63° 49', r =613. 


Hence the dip at the central station, on the 1st November, 
1838, was 71° 22'0, the central station being the same as 
before; consequently, the probable dip at that station, on the 
Ist January, 1837, was 71° 26'°4, 

Finally, if we combine these results with those of the former 


series, allowing weights in proportion to the number of stations, 
we find 


L = 71° 238°'7, M = +:292, N= + ‘517 
a= —60° 32', r ='594; 


L denoting the mean dip at the central station, on the Ist 
January, 1837. 


MAGNETIC SURVEY OF GREAT BRITAIN. 119 


Report resumed by Major Sabine. 


To the observations in Ireland I have to add a very careful 
determination of the dip at Lissadel in the county of Sligo, 
the seat of Sir Robert Gore Booth, Bart., made at my request 
with Captain Fitz Roy’s Gambey by Archibald Smith, Esq., of 
Jordan Hill. 


TaBLe XL. 
3 Poles. 
Lat. Long. Date. Hour. = @ direct, Mean. | Mean Dip. 
% | Greversed. 
1838. ; > 3 
54 93 | 8 33 |Sept. 19] Noon | 2 |« 71 57-5 | ° : 
B 71 57-6 |71 57-6 |} 
— 22} 2 p.m.| 2 |e 71 544 
B 71 55:3 |71 55 | 
— 24) 93 a.m.| 2 |a@ 71 54-5 +71 56 
B71 56 71 55-2 
— 25) 95 a.m.| 2 |@ 71 54-5 
B71 57:8 |71 56-2 


Collecting in one view the values of « and 7 obtained from the 
observations in Ireland, we have as follows :— 


TABLE XLI. 


Observer No. | Cent. Geog. Posit. Values of 
a Stations. 


Lat. Long. u r 


Lloyd, Fox, and Sabine) 34 | 5321 | 8 6 |-59 16] 0-578 
oil ae 12 | 5321 | 8 0 |-6349] 0-613 


Regarding the values of wand ras entitled to weight, propor- 
tioned to the number of stations, of which each is the represent- 
ative, we obtain — 60° 32! and 0'594 as the mean values derived 
from the Irish series, and corresponding to the mean geogra- 
phical position, 53° 21’ N. and 8° 00! W. 


120 EIGHTH REPORT—1838. 


Collecting in one view the values of uw and r at the central 
geographical positions in England, Scotland and Ireland, as 
they have been derived from the several series in each country, 
we have as follows : 


England, Lat. 52°38!. Long. 2°07!; w=—65°05'; r=0°575’ 
Scotland, — 56°49'. — 3°39'; u=—56°06'; r=0°549! 
Ireland, — 53°21’. — 8°00'; w=—60°32'; r=0°594! 


Whence it appears that the isoclinal lines do not intersect the 
geographical meridian at the same angle in the three countries ; 
that they form a greater angle with the meridians in England 
than in either of the other two countries; and that the angle 
is also greater in Ireland than in Scotland. 

It also appears that the distance between the lines is greatest 
in Scotland, less in England, and least in Ireland; the number 
of geographical miles, measured on the perpendicular, corres- 
ponding to differences of a degree of dip,—being 


109°2 in Scotland ; 
104°4 in England ; 
101°0 in Ireland. 


It follows, from the different values of 7, that the assumption, 
upon which we have hitherto proceeded in these combinations, 
of parallelism of the lines and their equidistance apart, does not 
hold good when applied to an area of the extent of the British 
islands, and not strictly so for any of its three portions; and 
that it is desirable to find a method of more exactly represent- 
ing the observations, by tracing each isoclinal line separately 
from observations nearly of its own value, and consequently but 
little removed from it in geographical distance. If we have 
the approximate values of w and 7 at any station where the dip 
has been observed, we may readily compute the latitude and 
longitude of a point furnished by that observation for the po; 
sition of the next adjacent isoclinal line. If the isoclinal lines 
sought are those of complete degrees (i.e. the lines of 69° 00’, 
70° 00’, 71° 00', &c.), and if the observation be also without 
fractional minutes—say, for example, 69° 00’—the point fur- 
nished by that observation for the line of 69° 00! is at the 
station itself. If the observation exceeds or falls short of 
69° 00! by a few minutes, the point furnished by it for the 
isoclinal line must be distant from the station a geographical 
space, equivalent to the value in distance of the fractional mi- 
nutes, as computed by the value of 7, and in the direction of 
w+90°. Thus, if D be the degree of dip represented by the iso- 


MAGNETIC SURVEY OF GREAT BRITAIN. 121 
clinal line, 6 the dip observed at a station, of which the latitude 
is A, then is (D—8) =" the difference of latitude, and (D—8) 

r 


COS@ sec 2 the difference of longitude, between the station and 


r 
the point which it furnishes for the isoclinal line. 

We have the values of wand 7 at the central geographical po- 
sitions in England, Ireland, and Scotland, as derived from obser- 
vation. If, for a general central station in the British Islands, 
we take the mean of the central stations in the three countries, 
viz. lat. 54° 16! N., long. 4° 35’ W., we may deduce the values 
of u and r for that station from equations of the form 


u,=U+tar+ by 
1=r+ar+ by, 


where w, is the angle and 7, the rate of increase at one of the 
three central geographical positions ; a, and 5, co-ordinates of 
distance in longitude and latitude from the general central sta- 
tion, expressed in geographical miles ; and « and y coefficients 
of the change in the values of w and r in each geographical mile, 
y in the direction of the meridian, and 2 in that of the perpen- 
dicular thereto. The mean results in the three countries will 
then furnish respectively the three following equations for the 
value of w ; 


England, 3905’ =u— 89x%— 98y; 
Scotland, 3366'=uw— 344+ 153 y; 
Ireland, 3632'=u+123%— 55y; 


The number of stations from which the mean results were ob- 
tained was, 


> proportion of 


In Ireland, 39 1 


In combining these equations therefore by the method of 
least squares, to obtain the most probable values of w, x, and y, 
we may give the weight of 3 to the English result, and that of 
unity to each of the two others. 

Pursuing the usual process, we derive u = — 60° 42'; x = 
+0°6; y=-+2°0: and we may compute the approximate value 
of u at any geographical position in the British Islands, by the 
formula 


u=— 60° 42' + O06 a + 2h, 


122 EIGHTH REPORT—1838. 


the origin of the coordinates, a and h being the general central 
station in 4° 35! W. longitude, and 54° 16! N. latitude. 
Proceeding in the same manner for 7, we have the 3 equations : 


England, + 0°575=r— 89x%— 98y; 
Scotland, + 0549 =r— 344%+4153y; 
Ireland, + 0594=7+41234% — 55y. 


Giving the English result the weight of 3, and each of the 
others that of unity, and deducing by the method of least squares 
the most probable values of r, x, and y, we obtain x= +°00007; 
y = —:‘00013 ; and r = 0°571, at the central general station 
in lat. 54° 16! and long. 4° 35! W. 

Whence the approximate value of 7 is found at any other geo- 
graphical position in the British Islands by the formula 


r = +0°571 +:°00007 a —:00013 4; 


the longitude and latitude of the general central station being the 
origin of the coordinates @ and 4. 

The points furnished by the several observations for the near- 
est adjacent isoclinal line, computed in the manner above de- 
scribed, are inserted in the general table which closes this divi- 
sion of the report. The table is in two parts; the one con- 
taining the observations, the other the deductions. In the first 
part are shown the observed dip, the latitude and longitude of the 
station, the date, the observer, and a reference to the particular 
table in which all the details connected with the observations 
may be examined. In the division which contains the deduc- 
tions, are shown the dip reduced to the mean epoch of the Ist 
January, 1837 ; the differences of latitude and longitude between 
the station and the point furnished by it for the nearest isoclinal 
line; the latitude and longitude of the points, and the values of 
u and 7, employed in their deduction. 

By the method thus described, the transfer of the observation 
to the isoclinal line involves no other material inaccuracy than 
such as may be occasioned by incorrectness in the employed 
values of «and 7. We may, therefore, examine the probable 
limit of the inaccuracy which may be thus incurred ;—30 mi- 
nutes of dip is the extreme fractional amount in any case for 
which a deduction is required: if we suppose an error in the 
assumed value of 7 equal to 0°01, which is nearly a fourth of 
the extreme difference found for England, Ireland and Scot- 
land,—the corresponding error in the geographical distance of 
the point from the station will be less than one mile. An error 
of 1° in the value of u, in the same extreme case of a fractional 
amount of 30! of dip, would cause an error in the position as- 


2 
ad 


MAGNETIC SURVEY OF GREAT BRITAIN. 123 


signed to the point of less than one mile in latitude, and half a 
mile in longitude. We may hence estimate the probable limits 
of inaccuracy in the extreme cases alluded to. It is obvious that 
when the fractional minutes in the observation are less than 
thirty, these limits are proportionally reduced ; and it is further 
plain that errors thus occasioned will be of a contrary nature to 
each other, according as the fractional minutes are in excess or 
in defect of the degree which the line represents. When, there- 
fore, the observations are numerous, and fall on both sides of 
the lines, as is the case in this survey, a mutual compensation is 
afforded, and whatever small inaccuracies there may be in the 
values of wu and, their ultimate effect on the lines may be re- 
garded as wholly insensible. 

If the observations at each station were free from instru- 
mental defect and local influence,—and if they were continued 
sufficiently long at each station to furnish its mean dip inde- 
pendent of diurnal and irregular fluctuations,—the points com- 
puted from them and transferred to a map would require merely 
to be connected in order to form the isoclinal line. As might 
be expected, however, the results of the observations are far 
from presenting this perfect accordance, especially in Scotland, 
where the prevalence of igneous rocks produces much disturb- 
ing action. An examination of the map, however, in which the 
points, and the stations they are derived from, are inserted, will 
show that, notwithstanding the disturbing causes referred to, 
they do arrange themselves in such manner as to leave very 
little uncertainty in any quarter in tracing the position and 
direction of each isoclinal line. Each line thus becomes an 
independent determination, derived from observations which be- 
long to itself alone, and uninfluenced by those which differ more 
than thirty minutes from the degree which the line represents*. 

By this method of combination, any departure from system- 
atic arrangement which might exist in any one of the lines 
passing across the British Islands, would become manifest at 
ouce to the eye. Individual stations there are, particularly in 
Scotland and the north of Ireland, which throw their points to 
some distance from their respective lines. In some very few 
cases, a group of neighbouring stations appears to be similarly 
affected. The most prominent instance of this is in North Wales, 
where there appears a decided disposition of the majority of the 


* This has been strictly adhered to in the table everywhere; and in the map 
everywhere over the surface of the land. The lines are extended in the map a 
short distance beyond the land; and as the observations which justify this ex- 
tension are few in comparison with those in other parts of the map, the determi- 
nations which fall nearly midway between two lines have, in these few cases, 
been given a bearing on the lines on either side of them. 


124 EIGHTH REPORT—1838. 


points to fall to the south of the line of 71°,.contrasted with and 
counterbalanced by an opposite tendency of the points furnished 
for the same line on the east of Ireland*. A more extensive 
research is necessary to determine whether, by multiplying the 
number of stations in these localities, this apparent irregularity 
would disappear, or whether the observations referred to truly 
represent what may be termed a district anomaly. Whilst, 
however, on minute examination the eye may rest on single 
stations, or on groups, which present examples of the slight 
irregularities here referred to, it cannot fail, on the general 
aspect of the map, to be struck by the absence of any important 
unsymmetrical inflections, and by the obvious general systematic 
arrangement of the terrestrial magnetism indicated by the lines. 
Here, as elsewhere, they present the features of the general 
magnetic system; the effects of local and partial disturbance 
being indeed discernible on close examination, but not being 
found of sufficient comparative magnitude to influence the 
general representation. 

The lines of dip as they appear on the map are slightly 
curved, being convex towards the S.E. If the extreme points 
of each line were connected by an arc of a great circle, the cur- 
vature of the arc, on the projection which is here employed, 
would be in the opposite direction to that of the isoclinal lines, 
or the convexity would be towards the N.W. Their departure 
from such a straight line on the surface of the globe (or their 
difference from great circles) is greater therefore than appears 
in this projection. 


* This apparent dislocation of the line of 71° between England and Ireland 
was noticed by Mr. Fox in the Report of the Royal Cornwall Polytechnic So- 
ciety for 1835. No trace of a corresponding irregularity occurs in the conti- 
nuity of the line 72° in crossing the Irish Channel. 


125 


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1858, 


VOL. Vil. 


EIGHTH REPORT—1838. 


134 


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138 EIGHTH REPORT—1838. 


DIVISION IL.—INTENSITY. 


The observations of the Intensity are arranged in three 
sections, in the same manner as those of the Dip. 


Section I.—ENGLAND. 


§ 1. Statical Method. 

Mr. Lloyd's Observations. These were made with the needles 
L. 3, L. 4, (page 82), in a 44 inch circle, made by Robinson. 
Table XLII contains the detailed statement of the obser- 
vations. 


TasLe XLII. 


[@ is the angle which the needle makes with the horizon, the 
southern arm being loaded with a weight. The negation sign 
indicates that the north pole of the needle is above the hori- 
zontal line. 


Needle L. 3, Needle L. 4. 
Stablinn, Jail Date alls ccoearguive: cal ee sina Ere 
Hour. Ther. ) Hour. ‘Ther. Q 

1836. | h m = athe hm ‘ Smee 

Dublin ...| April11) 0 18 p.m. | 57-5) — 15 23-4]! 0 43 p.m. | 57:8] — 13 26-4 
— 15} 030 53° |—15 3°6|| 0 08 53°5| — 13 21-0 

London ...} — 19] 1 0 55°8) — 18 43°5 || 1 28 56-8) — 16 31-9 
— 21] 2 58 585) — 18 47-6|| 2 37 58°5| — 16 59°9 

— 22) 0 30 59-2) — 19 6-0)| 0 14 60°5| — 16 57:6 

Shrewsbury} — 25] 3 10 55:2} — 17 31-1]| 2 45 55:0) — 14 56°8 
Holyhead .| — 27| 1 20 53° | — 16 19-4]! 0 40 54:0) — 13 55-6 
Dublin May 7| 1 32 57-2} — 15 52°5|) 1 10 56°5| — 138 22:5 
— 9/ 1 25 60° | — 15 52°5|| 0 50 60°5| — 13 18-4 

Dublin Aug. 5| 3 50 61:8} — 15 53°8]| 3 28 61-8} — 13 43°6 
— 6] 235 67:8} —16 9-2|| 2 10 66:5) — 13 34-4 
Birkenhead} — 8/10 Oa.m.| 68-9] —18 14:9|| 9 O.a.m.| 68-8) — 15 07-2 
10 50 66-8} — 18 07-5 || 10 20 67°5| — 14 58-4 

Shrewsbury] — 9/1] 40 67:2) —19 4-8])11 15 65°5| — 15 56:8 
0 07 p.m.| 665} = 19 2°5|| 0 20 p.m. | 66-4] — 16 20°8 

Hereford...) — 10]11 204.m.| 64-5) — 19 13°5||10 50 a.m. | 64:5) — 16 245 
0 05 e.m. | 66-4) — 19 11-2} 11 45 66:2} — 16 14:9 

Chepstow ..| — 12] 010 63-2} — 19 14-0||11 40 61-8} — 16 47:2 
Salisbury...) — 13]11 10a...| 71-2} — 19 58-8 || 10 45 69-5} — 17 36:0 
Ryde ...... — 15| Noon. | 71-5) — 20 33-2//11 30 72°5| — 18 24:2 
— 16] 0 45 r.m. | 72-2) — 20 36-1] 0 20r.m. | 700) — 18 208 

Clifton...... — 29)11 40..a. | 62-5) — 19 27-3 |] 11 15 a.m. | 62:5) — 16 44-2 
: 0 30 p.a. | 63-5) — 19 21-9|| O 5 v.. | 63:0) — 17 09°6 
Ryde ...... Sept. 24] 015 66-4} — 20 22°6|} 11 45 a.m. | 65°8) — 22 53°5 
110 64:6] — 20 16°6|| 0 40 r.m. | 65:0) — 22 45-8 

Brighton...| — 27}|11 15 a.m.| 61-5} — 20 41-4//1] 40 a.m. | 61:5} — 23 25-8 
Noon. | 61-0) — 20 21:9]| 0 30 2.M. | 61-2} — 23 11°38 

London ...| Oct. 4] 0 45 p.m. | 56-0} — 19 45-0|/ 1 20 57:0) — 22 54:3 
1 40 57:0} — 19 42-4|| 2 0 56-4) — 22 32:8 

Cambridge| — 8] 0 20 59:5] — 19 49-0]; 0 40 58:5| — 22 34:8 
1 10 56-2} — 19 39-0|| 1 35 55°8| — 22 29:1 

Lynn ...... — 10] 0 55 57:8} — 19 16:5 || 1 25 57-5| — 21 48°6 


MAGNETIC SURVEY OF GREAT BRITAIN. 139 


Tabular view of the variations of the angle 0, for the purpose 
of ascertaining the loss of force undergone by the needles, 
and the period of the change. The angles are reduced to 
the standard temperature, 60°*. 


Tasie XLIII. 


Station. Date. Needle L, 3. Needle L. 4. 
ie} ‘ ie) ‘ 
Dublin ..........- April 11 &c.] —15 21:2 | —13 307 
London AA — 19&c.| —18 55:9} —16 52:0 
Shrewsbur — 25 —17 388); -15 48 
Holyhead coh aed —16 3806| —14 52 
Dublin .........0+ May 7 &c.| —15 54:7 | —13 22:9 
Dublin ........... August 5 &e.| —15 53:3} —13 32:3 
Birkenhead...... _— 8 —17 58:1) —14 49-7 
Shrewsbury...... — 9 —18 527 | —15 59:2 
Hereford......... — 10 —-19 _ 36) —16 11-1 |. 
Chepstow ........ — iW -19 89} —16 443 
Salisbury......... — i138 —19 40:9 | —17 208 
Ryde ..........0. — 15&c.| —20 15:7| —18 46 
Clifton............ — 29 —19 1983 | —16 52:4 
Ryde ........068- Sept. 24 —20 10°83] —22 41:0 
Brighton ......... — 27 —20 29-7 | —23 166 
London ........ Oct. 4 —19 49:3} —22 488 
Cambridge ...... —_ 8 —19 50:1 | —22 36:5 
Lynn ............ — 10 —19 19:9} —2) 52-1 


Note by Mr. Lioyd.—It appears from this table that Needle 
L. 3 sustained a loss of force in the interval of time which elapsed 
between the two observations at Shrewsbury. Now the obser- 
vations at Dublin in April and May prove that the loss sus- 
tained by the needle during the series of observations in spring 
was comparatively trifling; while, from the results obtained at 
the same place in May and August, it appears that the mag- 
netism of the needle remained perfectly steady in the interval 
between the two series. We are consequently conducted to 
the conclusion, that the change occurred in the short interval 

between the observations at Dublin on the 5th of August and 
those at Shrewsbury on the 9th; and we have every reason to 
believe that it was previous to the observation at Birkenhead, 
and probably due to some accident in the passage across the 
channel. The magnetism of the needle appears to have been 
steady during the remainder of the autumn series. ‘This, we 
think, will appear from the difference of the angles at Shrews- 


* For the mode of effecting this reduction see Fifth Report British Associ- 
ation, page 147. 


140 EIGHTH REPORT—1838, 


bury and London (near the commencement and end of the se- 
ries, respectively), as compared with the difference observed at 
the same places in spring. 

With respect to Needle L. 4, the observations at Dublin in 
April and May show that its magnetism was perfectly steady 
during the spring series. This needle, however, sustained a 
very great loss of force between the two sets of observations 
with it at Ryde; and this loss appears to have been, in a great 
measure, a sudden one. But that the magnetism of the needle 
was not stationary during the remainder of the autumn series, 
will appear at once from a comparison of the observations at 
Shrewsbury in April and August. As we have no satisfactory 
means of determining the amount of this loss, and of interpo- 
lating a correction, we are forced to reject all the results ob- 
tained with this needle in autumn. 


TaBLE XLIV. 
Computed Intensity. 


Station, Date. Needle. Dip. London = 1°0000. 
1836, | ee 
April 19 3 2 1-0000 
London ...... — 21,22 | L.4 } 69 26-4 { 1-0000 
Shrewsbury... 4 = ae E } 70 276 { ab 
Holyhead...... Behe (eo) 088.4) ta 
Birkenhead...... August 8 | L.3 70 491 10112 
Shrewsbury...... _ 9 |L.3 70 27:7 1-0056 
Hereford......... —_ 10 | L.3 70 07-1 1:0046 
Chepstow......... — 12 |L.3 69 47:9 1:0041 
Salisbury ......... _ 13 | L. 3 69 23-1 10006 
Ryde ............ — 15,16 | L.3 69 02°6 0:9969 
Clifton............ —_ 29 | L.3 69 42°6 1:0030 
LOG i Baeeereroee Sept. 24 | L. 3 69 00°1 0-9975 
Brighton ......... — 27 | L.3 68 49-7 0°9955 
London ......... October 4 | L. 3 69 19-0 1:0000 
Cambridge ...... _— 8 | L.3 69 41-5 1:0001 
Ly Peep — 10 | L. 3 69 53-2 1-0030 
Means. 

Shrewsbury ...sessescesseeeeeees 1-0077 

Holyhead... - 10144 

iydeysescareecestueenseuneacescens 0:9972 


We have here eighteen results at the twelve stations, which 
being combined by the method of least squares, give the following 
values: a = + ‘000047; y = — ‘000067; wu = — 54°49; 7r = 
000082 ; the mean geographical position being lat. 52° 0’, and 
long. 1° 50’ W., at which the probable value of the intensity is 
1:0048. 


ae ae 
a, 
i 
~ 


MAGNETIC SURVEY OF GREAT BRITAIN. 14] 


Major Sabine's Observations.—The needle S 2 with which 
these observations were made, has been already described in 
the Reports of the British Association, vol. v. pages 141—149, 
It is 114 inches long, on Professor Lloyd’s statical principle, and 
is used in a circle made by Nairne and Blunt. The observa- 
tions, together with the deduced values of the intensity, are 
contained in the subjoined table, No. XLV. Each observation 
is a mean of forty readings, taken in four positions of the needle. 
The thermometer by which the temperature was registered was 


always enclosed with the needle in the dip circle. The values of 


—— are reduced to a standard temperature of 60°, in the 
sin (6 — @) 


manner described by Mr. Lloyd in the Transactions of the 
Royal Irish Academy for 1836; the coefficient of tr — 7' in the 
reduction, or the value of M a experimentally determined, is 
“000024. (See 6th Report, British Association, pp. 11, 12.) 
The observations with this needle at Tortington, in Sussex, 
in the summer of 1837, repeated in the autumn of 1837 and 


summer of 1838, and lastly in the autumn of 1838, produced 


on each occasion an almost identical result, and afford most 
satisfactory evidence of the unaltered state of its magnetism 
cos 6 


sin (6 — @) 


during the whole of the present series: the values of 


resulting from the observations at Tortington at the three 


epochs alluded to are as follows: 
Mean. 
May to September, 1837 . . . 0:95390 
October 1837 to July 1838 . . 0°95361 
October 1838 . . . . . . . 0°95375 


z cos 6 
To obtain the value of ait G20) 


the unity of the series, observations were made on three several 
occasions, and in three different localities; namely, in the gar- 
dens of the Little Cloisters, Westminster; in the nursery gar- 
den in the Regent’s Park; and in the gardens of the palace at 
Kew. The results were as follows: 


in London, to serve as 


Little Cloisters . . . 0°95245 
Regent’s Park. . . . 0°95684 
Kew Gardens. . . . 0°95479 


Mean. . . 0:95469 


142 EIGATH REPORT—1838. 


The mean of these values, 0°95469, has therefore been taken as : 
the equivalent to unity, and the relative values of the intensity 
at the other stations have been computed thereby, and are in- 
serted in the final column of the table. 


Taste XLV. 
i: I con Intensity. 
Station. Date. Hour. é 6 3 in G@-9) berm 
1837. “ ‘ 
June 1 | cece. 58 | —17 52-1 


Little Cloisters,}|— 1] ...... 58 | —17 566 
Westminster .) |July 25 | 9$a.m. | 70 | —18 07-4 
2. \. 


Tortington ...... Aug. 5|2 rat. |70 | —17 51-2 68 59°6 | -95390 | 0-9992 
5 


Shrewsbury...... — 19 | 45 pM. |68'5| —16 37° 70 24:9 | -96009 | 1-:0057 
1 


Aberystwith ... | — 91 | 3g rac. [66 | —15 415 70 25:9 | -96430 | 1-0100 


70 03:2 | -96041 | 1:0060 
70 04:0 | -96346 | 1-008] 


Dunraven Castles 69 45-7 | -96215 | 1-0078 


94948 | 0:9945 


D Sr G9 CO bo BY DD GD Or G1 St Or Go Co bo 
Z 
° 
° 
=] 
i=r) 
bo 
| 
— 
ir) 
ivy) 
i=) 
i—) 


Z 
[ah Rae Te Saat eal 


Zvm. | 48 | —18 24-7 4 
1Z p.m. |52 | —18 29-2 
68 52°3 
J 


MAGNETIC SURVEY OF GREAT BRITAIN. ‘ 143 


TaBLeE XLV.—(continued). 


E eer Intensity. 
Station. Date. Hour. é 0 3 an Q-8 Lenios: 
1837. pte ote 
Nov. 9 |llZa.m. |50 | —17 58 
— Zpm. |50 | —17 566 Qo I : 
Margate ......... re 1” ee Pas | te ALG 69 02:9 | -95180 | 0-9970 
— 10 Noon. |48 | —18 01-9 
— 14] Noon. |50 | —17 12:8 
Sond R — 14} 1 em. |50 | —17 14:7 
poon ¢ ss — 16|3 vem. |37 | —16 53-7 69 23°8 | -95684 | 1:0022 
gent’s Park).)| __ 16 | 4 vm. |37 | —16 52-6 


56:5) —17 24:2 
58 | —17 47:3 
58 | —17 58-4 
94:5} —17 51:3 
60 | —17 27-5 
60 | —17 25:2 


63 |—17 46-2 

63 | —17 45-7 

61 | —17 48:9 
19| 9 ass. |61 | —17 48-8 
19 | li em. 1,66 | —17 39-7 
19] 2 vm. |66 | —17 37°5 
23) 4 pm. |64 | —17 53-9 
23) 5 pm. |64 |—17 49-6 
.M. —18 12-9 
9 | 332m. }71 | —18 11:8 
19 | 7Za.m. |64 | —17 02:5 
19 | 9 am. |64 | —16 59-7 
19 | Noon. |72 | —16 56:8 
19 | 23 p.m. |72 | —16 52-2 
20 | 7k a.m. | 58°5| —16 42:8 
21 | 8 a.m. | 58:5} —16 57:1 
65 | —16 57-6 
24)4 po. | 58:5! —17 36°6 
25 | 7Za.m. |59 | —17 a 4 


Tortington ...... 68 54-0 | -95361 | 0-9989 


oq 
¢ 
= 

i] 
i=) 
iJ) 
~ 
5 
as 
_ 


69 19-0 | -95901 | 10045 


69 11-9 | -95607 | 1:0015 


Ft ea Pi Sa ta 
bo 
— 
QIH 
ba} 
a 


70 54-6 | -97200 | 1-0182 


> 
c 
09 
bo 
bo 
tole 
W 
5 
(=r) 
=r) 
I 
_ 
cy 
_ 


oy Z fo) 
IG ales a he SE i 
(og) 
SEB RNSSORR 
_ — 
Pe S Pe eg Be 
Pwo Ce ee] br 
BREE EERE ESSE 
or 
mr) 
ch 
I 
_ 
~ 
bo 
—) 
(o's) 
a 


97144 | 1-0176 


1:0147 
1:0159 


1:0176 


i fb elt 
— 
[=r} 
= 
_ 
re 
>> 
2 i 
or 
=r) 
| 
rT 
ise 
— 
© 
or 
= 
~_ 
—_ 
i 
i=) 
oo 


29 | 7ha.m. |53 |—14 48 }a O91 798890 
31 | 45 p.m. |62'5| —14 39-9 | 71 22-6 | -96987 
. 2| leew. [59 |—14 24-9 

2| 25 va. (59 |—14 22-9} 71 19-6 | -97150 

4 103 s.r. 60 |—14 19-1 | 


e 
Lo] 
o 


| | 


144 EIGHTH REPORT—1838. 


TaBLeE XLV.—(continued). 


5 Intensity. 
Station. Date. Hour, g 6 ge ey London 
= =1-0000. 


_—— ee | | | | | | 


Helensburgh ... 72 17-0 | -97870 | 1-0252 


‘97722 | 1:0236 


© 
oO 
oo 
ie.) 
= 
_ 
> 
5 
or 
oO 
| 
_ 
~_ 
ir) 


Worcester ie 69 06:7 | -95524 | 1:0006 


London (Kew é ; 
low 69 16:4 | -95479 | 1-0001 


oy 

s 

Qn 

& 

tj 

= 

— 

= 
=e = 
alt aad 

mt et 

o=—— 

_ 

mm 08 CO 

whales 

Pw 

SEE 

f—-Bor er) 

i) 

I 11 

tft be 

Go bo bo 

mt Or Or 

aU CO) G0) BOS 2 SDSS Ge G30 6S Coe Ca rics 

aoocc 

~_ 

i} 

— 

~ 

oo 


Uh JP, 
_ 
bo 
Ge 
al 
nematic siclie: decitatotee aes ae, aee ce 
s 
~~ 
ao 
I 
— 
_ 
i) 
Go 
v=) 


17 |llga.m. |61 | —17 45-9 
17 | Frm. |6l |—17 458 fs 52-4 | -95375 | 0-9990 


Omitting Dublin, which has been transferred to the Irish 
section, and taking a mean of the three results at Tortington 
for the intensity at that station, we have here twenty sta- 
tions in Britain to be combined by the method of least 
squares: whence « = + ‘000048; y = — 000062; u = — 52° 
27'; r = :000078; and f= 1:0075, the probable value of the 
intensity at the mean geographical position, of which the lati- 
tude is 52° 36’, and the longitude 2° 11’. 


Professor Phillips's observations.—These were made with 
a needle on Mr. Lloyd’s statical principle, employed in Mr. 
Phillips’s six-inch circle. The needle had been recently re- 
ceived from the maker (Robinson), when it was first used at 
York in June 1837; and the results obtained with it on the 
3rd and 5th June, compared with those on the 15th June, indi- 
cated that its magnetism had not become steady. ‘To obviate 
this inconvenience as far as might be possible, Mr. Phillips re- 
peatedly, during the series of his determinations, brought the 
needle back to York, and re-examined its magnetic state. 
We are thus furnished with observations at that station in 
June, August, September, October, 1837, and in February, 
1838, which are arranged in Table XLVI., and show the pro- 


MAGNETIC SURVEY OF GREAT BRITAIN. 145 


portion of magnetic force lost by the needle in the several in- 
tervals. It will be seen that the loss, on the daily average, 
progressively diminished ; and, excepting in the first interval, 
namely, between the 4th and 15th June, was not of sufficient 
amount to create much uncertainty in the results, after the ap- 
plication of a correction assigned in the usual manner, viz. a 
daily rate for each interval, obtained by dividing the whole loss 
in an interval by the number of days which it contains. In re- 
gard to the first interval, when the loss was considerable, and 
where a correction applied on the above principle can scarcely 
be supposed an exact representation of the facts, it fortunately 
happens that the six included stations are all in Yorkshire ; 
and thus, though an equable correction in this interval may 
make the values of the intensity at these stations appear more 
discrepant with each other than they otherwise would do, yet 
their collective bearing on the position and direction of the 
isodynamic lines is scarcely affected. 

By experiments with this needle in different temperatures, 
Mr. Phillips found 000090 the coefficient («) of (s—7’) in the 
reduction for temperature; which has been employed in re- 


ducing the values in the column —— to a mean temperature 
of 60°. 
Taste XLVI. 


Observations at York, collected in one view, to show the loss of 
magnetism sustained by Mr. Phillips’s needle. 3 = 70° 48'°8. 


Average 


Date. Therm, ) daily loss. 


June 3& 5, 1837 ...) 62-2 | — 15 24-9] 0-96632 
Se 68-2 | — 16 10-0| 0-96254 
ESS ee 67-5 | — 16 46:2| 0-95897 
= a ee 65-0 | — 17 00-0| 0-95747 
- Ay Pee 63-5 | — 17 06-9| 0-95665 
Feb. 19 & 20, 1838 ...| 35-5 | — 16 55-0] 0-95530 


Mr. Phillips’s observations at twenty-four stations in England 


are comprised in Table XLVII.; the values of — 9 are re- 


146 EIGHTH REPORT—1838. 


duced to a mean temperature of 60°: the two last columns con- 
tain the relative values of the intensity, in the first column to 
York, and in the second to London. The frequent repetition 
of the observations at York, at different dates, renders that 
station the proper base of Mr. Phillips’s series. The obser- 
vations at York and London in February and March 1838, _ 
furnish a direct comparison of the force at those stations, and 
by means of that comparison, a determination of its value at all 
the other stations relatively to the London unity. 


Tasie XLVII. 


Intensity. 


London | 
=1°0000. 


cos 8 


sin (0-8)| =P o000. 


Hour. | Therm. (7) ry 


Station. 


Boncaster 70 30-2| -96383 | 09971 


1-0096 


70 48-8} -96632 | 1:0000 | 1-0126 


53 | —14 51:3 | 70 59-2! -96848 | 1:0029 | 1:0155 
.| 425 | —15 08-7 | 71 03-2| -96583 | 1:0002 | 1:0128 ) 
.| 56 |—15 191] 71 04-0] -96606 | 1:0008 | 1-:0134 
m.| 52 —15 22:0 | 70 57:9} -96553 | 1:0009 | 1:0135 
Flamborough./Jine 11] 8 e.m.| 57 | —16 29:1 | 70 36:9} :95988 | 0:9958 | 1-0083 
Scarborough. .|June 13} 13 r.m.| 71 —16 28:3 | 70 41:8} -96111 | 0°9978 | 1-:0103 
Sheffield ...... June 17| 65 vm. be —16 18:0} 70 29°6| -96220 | 0:9998 | 1:0124_ 
Birmingham. ,|Jul 3 epm.| 73d | —17 046 t . : 
Birmingham. leat 8] 65 p.m.| 70 | —16 47-1 }70 07-2) 95897 |.0°9980 | .1:0108 
St. Clair’s......\July 19} 9 a.m.| 68 | —18 52:7 
St. Clair’s...... July 22} 3i p.m.| 76 |—19 O-1 | +69 01:2] -94786 | 0-9878 | 1-0002 
St. Clair’s......|July a Fe 66°5 | —18 42°1 
DWOgkiess-ssrecnd Aug. 1/4 vm} 67:5 | —16 46:2 | 70 48-8} -95897 | 1-:0000 | 1-0126 
Calderstone.../ Aug. 12)12 69:5 | —17 27:77 | 70 43-5} -95668 | 0-9981 | 1-0106 
Douglas ...... Aug. 17| 3 v.m.| 68:5 | —15 27:1 | 71 22-2} -96610 | 10081 | 1-0208 
Castletown .../Aug. 18] 9 a.o.| 66°2 | 15 29°8 | 71 22:5] -96564 | 10077 | 1-0203 
PeelCastleInn|Aug. 18} 2 vm.| 70 | —15 49-0 ale 4 & 
PeelCastleInn| Aug. 18| 32 rar. 69 | —15 39-7 |f71 240) 96454 | 1-065 | 1-0192 
Birkenhead ...}Aug. 26] 14 p.m.| 62 | —16 33:8 | 70 39:4/ -95980 | 10019 | 1-0145 
York.........../Sept. 7] 44 pm.} 65 |—17 0:0 | 70 48-8} -95747 | 1:0000 | 1:0126 
Coed .......00.. Sept. 20/12 68 |—17 22:8 | 70 40-9} -95560 | 0:9985 | 1:0110 
Bowness ...... Sept. 25] 93 a.m.| 54 | —15 547 | 71 18-4] -96229 | 1:0056 | 1-0182 
Coniston ...... Sept. 27] 8$ a.m.| 515 | —15 39°4 | 71 19°5| -96346 | 1:0070 | 1-0196 
Patterdale. ....|Sept. 27} 13 v.m.| 52 —15 55°5 71 19°6| -96202 | 1:0054 | 1:0181 
Penrith. ....... Sept. 28/10Z a.m.| 50 —15 51:0 | 71 28-4] -96222 | 1:0057 | 1:0184 
Carlisle, Sept. 29/103 a.sr.| 56°5 | —15 42°1 | 71 28-5) -96357 | 10072 | 1:0198 
Newcastle...... Sept. 30} 75 a.m.| 53 | —16 06:9 | 71 18-1} -96120 | 10047 | 1:0173 
Work’scccscecess Oct. 2/10 a.m.| 63 17 10°4 : . é 
York oc 6c..s053 Oct. 2) 4 pao} 64 | 17 35 }70 48:8) 95665 | 1-0000. | 1012s 
London .......|Mar. 28] 42 p.m.| 58 | —19 22-2 | 69 19°6/ -94346 | 0:9876 | 1-0000 
York: ..s..00008 Feb. 19} 9 am.| 33 | —16 54:8 . : é 
Yorks fascces Feb, 201 ta Sa| 38 | 16 a2 | $70 488] 95530 | 1-000 | 10126 


MAGNETIC SURVEY OF GREAT BRITAIN. 147 


If we combine the mean results at the twenty-four stations 
in this table by the method of least squares, we obtain the fol- 
lowing values: «= + ‘000061; y=—-000066; w=—47° 37’; 
r=000090 ; and f=1-0136, at the mean geographical position 
in lat. 53° 49’, and long. 2° 08’. 


Mr. Fox's observations.—These were made with a 4} inch 
needle, on the principle described by its maker, Mr. T. B. 
Jordan, of Falmouth, in the third volume of the ‘‘ Annals of 
Electricity,” &c. The needle has a small grooved wheel on its 
axle, which receives a thread of unspun silk, furnished with 
hooks, to which weights may be attached. The weights em- 
ployed were successively 2°0 grains, 2°1 grains, 2°2 grains ; and 
with each weight the intensities are in the inverse ratio of the 
angle of deflection produced, corrections being applied for 
differences of temperature at the different stations. The fol- 
lowing table exhibits the angles of deflection occasioned by 
the respective weights, and the values of the intensity deduced 
therefrom. The angles are reduced to a common temperature ; 
1° of the centigrade scale having been found by experiment to 
be equivalent to 2’, or 2'-4 in the angle. 


Taste XLVIII. 


Station. Date. Weight. a aa | Intensity.| Mean. mnaone 
1838. | Grains.| 5 ‘ Mean of results in 
29 20 |48 36-7} 1-0000 a ag to of Mai. 
London .....+sss++: Janet & 8| 22 [51 55:3] 1-000 | + 1.0000|4 gen Lanes in the 
Oe 2-2 |55 33-0| 1:0000 and at West. 

bourne Green. 
| 2:0 48 57 | 0-9938 } In the grounds 
Eastbourne ...... June 20 21 (52 19 0:9921 | +0-9937 of Davies Gil- 

22 155 57 0-995. 1 bert, Esq. 


Eastwick Park...) June 16 51 57 09996 | }0:9993| In the grounds. 


Combe House ....! July 2 | 1:0026| In the grounds. 


July5 &7 


toIDAD tONDAD RO LD kD 
Neo NES NK OS 

or 

—_ 

~ 

or 

_ 

bo 

rg 


grounds. 


ee a a ae as aa ae ae 


51 48 | 1-0017 roots 1 Mr. Fox's 


148 EIGHTH REPORT— 1838. 


§ 2. By the Method of Vibrations. 


The observations by this method include twenty-seven sta- 
tions; i.e. 18 by Captain Ross; 7 by Major Sabine; and 2 by 
Mr. Lloyd. 

Ist. Captain Ross’s determinations were made with a cylin- 
der (X) vibrated in an apparatus on the well-known plan of M. 
Hansteen. The loss of magnetism sustained by the cylinder 
during the time of its employment, from July 1837 to June 1838, 
was very considerable, and was occasionally so irregular as 
to prevent any satisfactory conclusion whatsoever being drawn 
from the observations. On a careful examination, there ap- 
peared two intervals, viz. from the middle of September to the 
middle of November 1837,—and from April 24 to June 5, 1838, 
—during which there was reason to infer that the loss of mag- 
netism, though considerable, .had been tolerably uniform and 
regular. During the second interval, viz. from April 24 to 
June 5, 1838, on both which days the cylinder was vibrated in 
London, the increase in the time of vibration at the same sta- 
tion affords a direct measure of the diminution in its magnetic 
intensity ; and being divided by the number of days comprised 
in the interval, furnishes the amount of the daily correction. 
But in the first interval we have the additional disadvantages 
of having no direct observation showing the amount of the loss 
of magnetism, and no direct comparison with the force in 
London: and it is necessary, consequently, to have recourse to 
indirect means for the purpose of determining these particulars. 
On the 19th of September, 1837, Captain Ross vibrated cylin- 
der X at Birkenhead; and on the 21st of September, at Dou- 
glas, in the Isle of Man. In Table XLVII. we have the 
value of the intensity at both these stations relatively to the 
London unity, determined by Mr. Phillips; and in Table 
XLIV. we have Mr. Lloyd’s determination of the force at 
Birkenhead. We may employ these determinations to supply 
the time of vibration in London corresponding to the observa- 
tions with the cylinder at Douglas and Birkenhead. In like 
manner we may accomplish a second indirect comparison with 
London by means of Captain Ross’s observations at Falmouth — 
on the 18th of November, 1837, combined with the values of 
the intensity at that station determined by Mr. Fox, (Table 
XLVIII.), and Major Sabine, (Table XLV.). The several 
observations and processes by which the times of vibration 
of the cylinder in London have beenderived at different epochs, 
are comprised in Table. XLIX.; and in its final column is © 


Time of 


Station. Date. [vibration at 
60°. 


1837. 


Birkenhead...|Sept. 19} 275-22 


Douglas ...,..|Sept. 22) 279:27 


Falmouth...../Nov. 18 


1838. 
London,.......|April 24 


271:48 


275°84 
London........ June asl 280-06 


them. 


MAGNETIC SURVEY OF GREAT BRITAIN... 


Taste XLIX. 


Observed 
dip. 


69 


‘ 
350 


20°3 


161 { 


15:0 


15:0 


Tasre L. 


Corresponding 
times of vibration 
of Cylinder X in 

London. 


Intensity of 
London = 1°0000 


10145 Phillips 


1-0112 Lloyd } aes 


268:37 
1-0208 Phillips | 268-30 
1:0015 Sabine : 
a eoiehnce } eveneveeee 27170 
ET ie Taito RAE vere 27584 
POOGON shan. ees: 280-06 


149 


shown the average daily loss of magnetism experienced in each 
of the two intervals; which is subsequently applied in Table 
L., in assigning the corresponding times of vibration in Lon- 
don, on days when the cylinder was employed elsewhere. 


Daily loss 
of force in 
the respec- 
tive interr 


vals. 


Table L. contains the observations made by Captain Ross 
with cylinder X, and the values of the intensity derived from 
The coefficient in the formula for the reduction to a 
mean temperature, is ‘00017: the reduction has been applied 
in the column entitled “ corrected time.” 


; Correspond- y 
Time of Phases Intensity. 
Station. Date. ; ay ; Corrected | Observed | ing time of L 
ents Hour EE wibhantecnis: Su Dip. hea = "0000. 
1837. | h m i s s 20 a} 8 
Birkenhead...|Sept. 19) 1 48 p.m] 70 | 275-81 yes . L rf 
217 70 |275-58 275-22 170 35:0) 268-45 10128 
Douglas, (Isle|Sept. 22) 9 47 a.m.| 60 | 279-2 : : 3 2 
of Man). : 10 36 60 | 279-35 27927 |71 20:3} 268-30 1-0208 
Pwllheli ...... Oct. 14] 5 11 p.u.| 47 | 274-62 
— 15) 8 55 am.) 47 |275:30$] 275-71 |70 32:5} 269-81 1:0173 
iis 10 57 60 | 275-98 
arlbro’......) — 18/10 50 58 | 27053 ; : ) ; 
= 11 14 60 | 270-75 27068 |69 25-4; 270:00 | 1:0018 
ifton......... — 22) 230 pm. 56 |271-4 : : “Gi . 
3 : 2 55 56 271-37 271:66 |69 84:0) 270-24 1-:0031 
embroke,....) — 26) 1 17 56 | 272-75 ; : : : 
1 48 56 | 272-80 27295 |69 55-9) 270-48 1-0128 
VoL. vir. 1838. L 


150 


Station. 


seneee 


Aeeeeee 


seeeee 


Lowestoffe.... 


seneee 


eeeeeeer 


Date. 


Hour. 


EIGHTH REPORT—1838. 


Tase L. (continued.) 


Corrected | Observed 


Temp. ‘ime, Dip. 


vibrations. 


Ss 
273°38 
27312 
273°23 
271:42 
270:85 
271-00 
271-02 
270:98 
270-93 


275°52 
275°51 
284°43 
284-85 
285°7 
aroun 
286-68 
285°82 
285-0 
285-08 
284-07 
283-02 
283-7 
283°67 
281-05 
281-38 
279-90 
279:73 
280:30 
280-68 
280°65 
281-0 
281-10 
281:17 


260-13 
279-93 
280-20 
280-43 
280:53 


79 


280°66 |69 29-2 


280:00 | 69 15:4 


280:27 
280-32 
280-25 
280°53 


280-06 | 69 15-0 


Correspond- 


ing time of 


vibration in 


ndon, 


278-90 


279°50 


280-06 


Intensity. 
London. 
=1°0000, 


a 


MAGNETIC SURVEY OF GREAT BRITAIN. 151 


2. Mr. Lloyd’s observations were made with two cylinders, 
L (a) and L (6), vibrated in Hansteen’s apparatus. The 
agreement of their times of vibration in Dublin, in April and 
May 1836, is an evidence that their magnetic state remained 
unaltered in the interval. The values of the intensity at 
Shrewsbury and Holyhead are deduced, in relation to the Lon- 
don unity, by means of the force in Dublin; which, in a sub- 
sequent part of this Report, will be shown to be 1:0195. The 
coefficient in the formula of reduction to a mean temperature, 
is ‘(00025 for both cylinders. (5th Report, B. A., pp. 119 and 
120.) 


Taste LI. 


Time of 2 
A Ob: tit Intensity, 
Station. | Date. | Cyl. | Temp, Vib oone,|  CmeMeA Tite. Dip. | London = 1-000. 
1836. a s s ate 
Dublin.../April 11] L (a)| 56-2 | 243-56 | 243-76 
Sas © 61-0 | 243-96 | 243-88 243-78 10195 
= 15 565 | 243-50 | 243-69 
April 11] L (6)| 565 | 292-93 | 293-16 71 08:5 | ch 
01d 59-2 | 293-50 | 293-53 b293-33 10195, 
= 15 56:8 | 293-09 | 293-29 
Shrews-|April 25] L (a)| 620 | 241-64 | 24151 194)» 
bary...! 62-0 | 241-68 2ir5 J 24158 i Gig pg {10080 
: — 95| L (b)| 70-0 | 291-58 290-83 76 | 1.0066 
|Holy- ,|April 27| L (a)| 54-2 | 244-08 | 244-421 5,,. 
esd... 53-2 | 244-02 s44a 442 des a orog f0195 
pe — 27} £ (6) | 59-0 | 293-87 293-92 1-0198 
Dublin...|May 7 L (a) 57°6 | 243-96 244-10 243-96 } 101959 
ae 61-0 | 243-90 | 243-83 LT 03 ronan 
May 7| L(2)| 58-0 | 292-95 |293:08 | 995.94 { aan 
eh 61-0 | 293-43 | 293-34 


3. Major Sabine’s observations were made with Mr. Lloyd’s 
cylinders L (a) and L (4), and with a pair, in all respects simi- 
lar, designated as L (3) and L (4). The results are comprised 
in the two following Tables, LIi. and LHI. Table LIL. con- 
tains observations made to determine the value of the intensity 
at Tortington, in Sussex ; and Table LIT. the values at six other 
stations in Great Britain: in Table LIII. the value of the force 
in Dublin =1-0195, has supplied the means of checking the 
magnetism of the cylinders. 


L2 


—— 


152 EIGHTH REPORT—1838. 


Taste LII. 


Deduction of the Intensity at Tortington. 


1, By comparison with Dublin. The observations at Dublin are by Professor 
Lloyd; those at Tortington by Major Sabine. The intensity at Dublin 
= 10195. The co-efficient in the formula for the reduction to a mrean 
temperature of L (3) =:00027; of L (4) =:00022. 


, Time of | Corrected ; Intensity. 
Cyl. 5 Date, B . * A Lond | 
yl Station ate, Hour. Therm wae tia, Time. Dip E =e on | 
Eee ae peieiode eee a 
1838. | h m > Se s. Bari At 
Tortington ...|Feb, 9] 4 40 p.m. | 42 | 295-67 ‘ ‘ | 
: 110) 1 St 36 | 295-09 [| 297°05 | 68 5571 | 
Dublin... March 3] 1 37 46:2 | 307-79 | 
1L.(3); — 32 02 47 |308-00 $| 308-81 | 70 58-4] 0-9963 | 
— 5303 46-5 | 307-35 J a} 
Tortington ...|March 10} 1 44 46 | 296-74 3 - 
3 — 10|238 45-5 |296:53 5| 297°75 | 68 55:1 


ee —$— 


Tortington...|Feb. 9) 5 O9 p.m. | 41 | 271-22 , : 
a — 10) 0 34 36, {970-787 | 24°38 | 88 ybo2 | 
L (4 Dublin,.,...... March 3} 2 46 46°8 | 282-58 \} 
(4). 5 ) 3) SiGe 44-2 |282-58 || 283-40 | 70 58-4] 0-99865 |) 
—) 5) BaD 47-2 | 282-57 | 

Tortington ...|March 10/10 43 a.m. | 49 | 272°53 : 2 
8 ee ag 46 |971-98 7 | 27299 | 68 55:1 


2. By direct comparison with London. The London observations were made in | 
the Palace Gardens at Kew. | 


j 


r| 
Intensity. | 
Station. Date, Hour, | Therm.) Yanestin” Dip. Londo | 
: 1838. | h m | 
London......... Oct. 13) 30 39 = | 237-77 : k 
Lia | = ial) 818) *| ao garen 79828 (8 Ae 
Tortington ...| Oct. 18 0 08 52 = | 23665 237-16 | 69 53° i 
— 18| 027 | 53 |236-80 
London....... «| Oct. 13} 11 45 44 | 303-92 : i | 
L (6). a 13} (013. | 44 | 30805 f 30521 | 69 164 | 
Tortington ...| Oct. 17 1 28 58:5 | 303-26 0:9965 
— 18; 1017 48:0 | 302-18 + 303-20) 68 53:5 


— 18} 11 07 505 | 302-46 


ne ff 
| 


The values of the intensity at Tortington, relatively to unity in London thus de- |) 
duced, are as follows: 
L (3), 0:9963; L (a), 0:9986 ; 
L (4), 0:9985; L (4), 0:9965 ; 
Mean, 0:9975. 


MAGNETIC SURVEY OF GREAT BRITAIN, 158 
Taste LIII, 
Deduction of the Intensity at Six Stations in Britain. 
L (8). 
Time of 100| Corrected | Observea | ng Tie of | Wtensity- 
. I 
eon. Date Hour, Therm. Vibrations, "Tae, Dip, Vibration in Lee 
London. 
/ 1838. |h m i s s haat s 
ondon ...... June 1/10 21 4.m.) 62 284-17 : & p ; 
| ee read (Sak17 (| Ao Ge tea) 28S Oe 
Ry gg) ) 10 ze 67 283.66 [| 28840 | 69 12-0] 28304 | 0-997 
es --- pie ads aa aes re288 | 292-32 | 70 54-6] 28387 | 1-0195 
Whitehaven...|Aug. 16 425 | 57-5 |294-46 | 204-64 | 71. 10-7| 283-94 | 1-0180 
fleweastle ....Aug. 28/228 | 71-5 |295-22 | 294-38 | 71 09:0| 283-94 | 1-0183 
iL (: 
| a Ae eS dari 86 | 246301) o4577 | 70 546| 23860 | 1-0195 
Whitehaven.../Aug. 16 455 | 57 | 247-81 | 248-00 | 71 10-7| 238-80 | 1-0169 
f 3 A . . 
fey ane: 28,257» 735 248-074 t| 24772 | 71 090| 23880 | 10177 
onehouse ...|Sept. 31130 | 59 | 248-86 | 248-92 | 71 19:6} 23880 | 1-0171 
felensburgh.. wa 5 ss >. a gate 253-58 | 72 17 238-80 1:0310 
ordan Hill.../Sept. 13] 3 24 59 253°66 | 253-72 | 72 14 238-80 1:0273 
ee. Oct. fee es cee 238-98 | 69 16-4| 238-98 | 1-0000 


follows: 


The results in Table LIII., collected in one view, are as 


a a eee i ee 


Intensity, London = 1:0000. ame a ae 
Station. Station. 
L (4). L(a). Mean. L (a). 
_ |Whitehaven......... 10180 | 1:0169 | 1-075 |/Helensburgh........]  1:0310 
: Newcastle ......... 10183 | 10177 | 1-0180 ||Jordan Hill......... 10278 
|Falmouth....... ....] 0°9997 | «sss 0:9997 ||Stonehouse .........| 10171 


If we combine, by the method of least squares, the results at 
| the twenty-seven stations at which the intensity was thus de- 


* Observed by Mr, Fox. 


t Observed by Captain Ross, 


154 _EIGHTH REPORT—1838. 


termined by horizontal vibrations,—namely, eighteen stations 
by Captain Ross, exclusive of those which have served to ex- 
amine the magnetism of the cylinder; two stations by Mr. 
Lloyd; and seven by Major Sabine,—we obtain the follow- 
ing values: x= +*000064; y=—-000069; w=—47° L4!; 
y ='000094. The mean geographical position is 52° 43! N., 
and 2° 18’ W, 


If we now collect in one view the several values of uw and r 


which have been obtained from the intensity observations in 
England, we have as follows: 


Tasue LIV. 
n eogra- 
No. of peal Pontion. Values of 
Observer. Method. Stations: ey ee 
Lat. | Long. u r 
lous ol ° ‘ 
Lloyd ......... Statical ...... 12 52 01} 1 50 | —54 49 | 000082 
Phillips ...... Statical ..,... 24 53 49| 2 08 | —47 37 | 000090 
Sabine......... Statical ...... 20 52 36) 2 11 | —52 27 /| -000078 
Ross Hori 1 
Sabine }...... orizents 27. +|52 43/ 2 18 | —47 14|-000094 
vibrations 


If we regarded the several values of w and r in Table 
LIV., as entitled to weight proportioned to the number of 
stations of which each is the representative, we should assign 
a preponderance to the values obtained by the horizontal vi- 
brations, which the circumstances of the observations from 
which they are derived would scarcely justify. To give them 
exactly their just weight, would require a lengthened investiga- 
tion of the respective probable errors, not only of the two me- 
thods, but of the horizontal method under some disadvantages, 
as shown in page 145. ‘The occasion would not justify the ex- 
penditure of the necessary time and labour; and I have assign- 
ed the arbitrary value of 18 to the horizontal deductions from 
the twenty-seven stations; making, in this particular instance, 
three horizontal determinations equivalent to two statical. Thus 
weighted, we obtain —50° 48! and ‘000086 as the mean values 
of « and r derived from the English series, corresponding to 
the central geographical position in 52° 48! N. jat., and 2° 07 
W. long. 


£ 
.7 


MAGNETIC SURVEY OF GREAT BRITAIN. 155 


Section II].—Scoranp. 


§ 1, Observations by the Statical Method. 


Major Sabine’s Observations——These were made in the 
summer of 1836, with the statical needle S (2); an account of 
them is contained in the report on the Scotch Magnetical 
Lines, in the 6th vol. of the Reports of the British Association. 
Between the 30th of July and the 4th of October, in which in- 
terval the magnetism of the needle was shown to have sustained 
no change, twenty-two stations were observed at, including two 
in Ireland, viz. Bangor and Dublin. These are now transferred 
to the Irish Series, and being thus included in their more appro- 
priate place, will be omitted here. At the time of the publica- 
tion of the Scotch report, no direct comparison had been made 
of the intensity in Scotland with that in London; but its values 
at the several Scottish stations relatively to London were given 
provisionally, by means of the observations in Dublin, and by 
adopting 1:0208 as the ratio of the force in Dublin to unity in 
London, according to a determination of Mr. Lloyd’s, published 
in the Transactions of the Royal Irish Academy, in 1836. The 
values at the Scottish stations were consequently subject to 
be altered by any modification which Mr. Lloyd’s determina- 
tion in Dublin might subsequently receive. In the present 
report Mr, Lloyd has given a corrected value for the force in 
Dublin, resulting from a much larger number of determinations, 
The corrected value is 1:0195. With this value, therefore, 
and the comparative observations at Dublin and Helensburgh, 
published in the Sixth Report of the British Association, we 
may now derive a more correct expression, relatively to London 
for the intensity at Helensburgh as the base of the Scottish 
determinations. 

The observations contained in the Scotch report presented 
a double comparison between Dublin and Helensburgh: one 
by the observations of the 22nd July, in Dublin, and the 27th 
July, at Helensburgh; the other by those of August 2, and 
September 13 and 14, at Helensburgh, and October 4, at Dub- 
lin, They are presented in the following table. 

Note.— Between the first and second comparisons the needle 
sustained an accident, which is related in the Scottish Report, 
and which accounts for the angles of deflection being different 
in the two comparisons. 


ni 


156 EIGHTH REPORT—1838. 


Tasre LV. 


Intensity. 
: __ cos 6 
Station. Date. sin (6 — 0) Se Bn 
1836. 
Dublin ......... July 22 94843 1:0000 | 1:0195 


Helensburgh ...| July 27 95478 || 1:0067 | 1:0268 


Helensburgh ...| Aug. 2 
Helensburgh ...| Sept. 13& 14 
Dublin ......... Oct. 4 


94572 || 1-0062 | 1:0258 
93993 || 1-0000 | 1:0195 


: 02 4 
Whence it results that (ees) = 1-0261 expresses 


the force at Helensburgh relatively to unity in London, as de- 
rived through the medium of Dublin. 

In 1838 I visited Helensburgh for the purpose of obtaining a 
direct comparison with London. The observations which I then 
made are included with the series already given in Table XLV; 
their result is 1:0252. The near agreement of this result, with 
that obtained in 1836 through the medium of Dublin, is satis- 
factory, both in confirming the relation of the Scottish intensi- 
ties to London, and in showing the confidence to which this 
mode of experiment is entitled. I have taken 1°0258 as the 
force at Helensburgh, considering the determination through 
Dublin as entitled to rather the most weight; and have com- 
puted from it the value of the intensity at the other stations, 
as inserted in the final column of Table LVI. 


Tasie LVI. 


Intensity. 
cos 6 
Station. Date. Ther. 0 0) eG Helensburgh| London 
Temp. 60°} =1°0000 | = 1-0000. 
Aue? |@\-B BOT Vc ihe 
ug. — C 2 . - 

Helensburgh { Sept. 13&14| 64 |—19 06-1 }r2 16°8| -94572 1-0000 1-0258 
Cumbray ...... July 30 64 |—18 31-9) 72 01:2} -94839 1-0028 1:0257 
Tobermorie ...| Aug. 10 70 |—15 29:3) 73 07-7)| -96452 10199 10462 
Loch Slapin ...J — 14 56 |—15 59 73 02-2} -96130 10165 1:0427 
Glencoe.......+. — 7 57 |—17 50°8| 72 17-2} -95173 1:0064 1:0324 
Taverness | Zhe, ee Be ae }v2 46-5| -95718 | 1-0121 | 1-0382 
Golspie ......... — 23 51 |—17 08-4] 72 55-6} -95510 1:0099 1:0360 
Gordon Castle | — 25 60 |—16 52-4) 72 40°9| -95693 1:0119 1-0380 
Alford ......... — 27 57 |—18 22 72 22 =| -94900 1:0035 1:0290 
Braemar......... — 30 44 |_18 40-1| 72 14:2) -94668 1:0010 1:0269 
Blairgowrie ...) — 31 59 |—18 06-1} 71 54:7| -95052 1-0051 1:0310 
Newport......... Sept. 1 60 |—18 40:8} 72 17:5) -94745 1:0018 1:0277 
Kirkaldy ...... — 38 60 |—18 37:7; 72 11 | -94769 1:0021 1:0279 
Melrose ......... — 6 51 |—19 43:7} 71 387 | -94111 0:9951 1:0208 
Dryburgh ...... — 7 56 |—19 56:1| 71 33:7} -94023 0:9942 1:0199 
Edinburgh...... — 8 55 |—19 24 71 49:4) -94320 0:9973 1:0231 
Glasgow......... — 9 56 |—19 24 72 01:7 | 94330 0:9974 1:0232 
Loch Ranza ...} — 16 57 |—18 55°9| 72 23-0} -94600 1:0003 1:0261 
Cambleton...... — 16 53 |—18 16:1} 71 56 | -94925 1:0037 1:0296 
Loch Ryan — 18 52 |—19 31:8] 71 43:5 | -94230 0:9964 1:0221 


FP 


MAGNETIC SURVEY OF GREAT BRITAIN. 157 


In the discussion of these observations in the 6th Report of 
the British Association, I have adverted to the frequent in- 
fluence of the igneous rocks in Scotland in producing what 
may be termed station error. In the table in page 20 of that 
Report, the intensities observed at Tobermorie, both by the 
statical and horizontal methods, are shown to have been af- 
fected, apparently by an error of this nature, to a degree much 
exceeding that of the results at any other station. In com- 
bining the results of both methods, therefore, for the values 
of x, y, &c., I have thought it right to omit altogether the inten- 
sities at Tobermorie. We have, therefore, the statical results 
at nineteen stations to combine by the method of least squares, 
whence we obtain the following values: x = + 000083; 
y= — 000107; «= — 52°15’; r= 000136. The mean geo- 
graphical position is in latitude 56° 22’ N. and longitude 
4° Ol’ W. 


Captain Ross's Observations.—These were made with two 
needles, R L (3) and R L(4), on Professor Lloyd’s principle, used 
in Captain Ross’s six-inch circle. One of these needles (R L 3) 
appears to possess the peculiar property of preserving its mag- 
netism unchanged in different temperatures, requiring no re- 
duction to a mean temperature. ‘Cable LVII. contains a series 
of experiments with it, made by Captain Ross, by which it will 
be seen that in differences of temperature, including the whole 
range of natural temperatures to which it is likely to be exposed, 
the time of vibration of the needle remained unaltered. 


Tasxie LVII. 


Observations to investigate the influence of differences of tem- 
erature on the time of vibration of Captain Ross’s statical 
needle R L (8). 


Time of 100 Time of 100 
Date. Hour, Ther.| Horizontal Date. Hour. Ther.| Horizontal 
Vibrations. Vibrations. 
1839. |h m i s 1839. | hm s s 
Jan. 17.)10 39 a.m.| 32 428°4 Jan. 17.| 2 29 r.m. | 60 428-0 
10 54 32 4284 2 45 56 428-2 
11 42 98 428°8 3 01 53 428°2 
11 58 92 428-4 3 16 51 428-0 
| 0177. | 83 428°2 3 32 50 428-4 
0 56 92 428-4 Jan. 18. |10 324.m. | 28 428-4 
111 87 428-4 10 47 29 427°8 
1 27 81 428°8 11 08 30 428°4 
1 44 75 4286 11 34 30 428°4 
1 58 7 428-2 11 49 30 428-6 
2 14 64 428°4 0 05 p.m. | 30 428°5 


The following table, No. LVIII. contains two series of ex- 
periments of a similar nature, with R L (4), one made by Major 


| 


158 ' EIGHTH REPORT—1838, 


Sabine, and the other by Captain Ross, the results according 
extremely well in the value of the coefficient deduced. 


< 


Tasre LVIII. 


Observations to ascertain the coefficient in the formula for reduction to a mean 
temperature of Captain Ross’s statical needle R L (4). 


Major Sabine, Tortington, December 18, 1838. 


Time of 100 


Hour. Temp. | Vibrations. Means. 
hm “ s 
10 38 a.m.| 47 480-4 ; ; 
11 34 yg 0 alle call 2(T—T") 
Here, in theformule a-yaapeeea 
ot 

1 57 p.m. | 109 480:8 T = 48025; T—1 = 0°75 « 
2 22 103 | 481-4 4 | 481-0atl03:3 |; _ ~ — 55°8; whence o — 
2 42 98 480°8 000056. 

5 02 49 479-4 

6 43 48 480:8 480-lat 483 

7 44 48 480-0 

Captain Ross, London, February 21, 1839. 
Hour. Temp, Pig of 78 Means, 

hm 3 oe _ 

1 14em.} 38 4: ° 

1 45 38 | 47493 }|47422 0038 

219 104 47496 

2 41 103 | 474-93 : 

3 7 | 103 | 47461 (| 47490 at 1025 | on = 474-2; 7 — T= 1916 
3 30 100 475°01 tT — 7’ = 45°%1 ; whence, a = 

“000054. 

3 51 88 474°36 

4 34 77° | 474-72 

4 53 71 474-66 474-51 at 75°7 

5 15 67 474°30 

8 7 50 | 473-98 

8 82 50 | 474-08 } 474-05, 24 50 


By the mean of the two determinations a ="000055 ; which being multiplied by 
43429, the modulus of the common system of logarithms =-000024, the coeffi- 
cient of (r—7’) in the correction for temperature. 


MAGNETIC SURVEY OF GREAT BRITAIN. 159 


In the following table are collected the observations made 
with these needles in London, in July 1838, and in December 
of the same year, for the double purpose of examining the 
steadiness of their magnetism in the interval,—during which 
they had been employed in the observations in Scotland now 
under notice, and in a similar series in Ireland,—and of deter- 
mining the angle of deflection in London as the base station of 
both series, 


Taste LIX. 


cos 4 


Needle.| Date. Hour, |Ther, gin (@— 6) Intensity. 
1838. |h m H 
July 7/5 30r.m.) 70 
|| July 12)0 30 70 "89683 | 0:9986 
ap —— |1 30 70 
fe 1-:0000 
fam Dec. 5 |3 O 45 by 2 
3 40 45 89932 | 1-:0014 
Mean. 
*89807 
July 10 
July 12 “98061 | 1-:0005 


On comparing the observations with both needles in July 
and in December, we may conclude that the magnetism of 
both had remained unchanged during the interval; the small 
differences are only such as frequently occur on different days ; 
they are, moreover, in different directions, and so far will com- 
pensate each other in the final deduction, 

In ‘Table LX. are comprised Captain Ross’s observations 
with these needles at nine stations in Scotland and the north 
of England. 


F 


160 EIGHTH REPORT—1838. 
Taste LX. Needle, R L (3). 
Intensity. 
Station. Date. Hour Ther. () 6 en oni 
1838. | h m bs ape o ,__ | Therm. 60° 
Aberdeen ...| July 19} 3 Op.m.| 63 | — 23 82°3| 72 27°6 92185 | 1:0266 
Lerwick...... — 25| 3 Ovm.| 54 | — 22 29-1 
— 26] 0 30 53 | — 22 33:1) +73 44:9 92947 | 1-0351 
110 53 | — 22 21:8 
Kirkwall...... Aug. 1/11 30a.m.} 60 | —22 4:3 ei 
b a0 | Go |— a2 s/t 78 204 | 93081) 1-0366 
Inverness .... — 14] 2 30r.m.] 59 | — 21 49°6 4 : 
3 5 | e9 | wal san| $72 462 | 93118] 1-0370 
Newcastle ...) — 29} 4 Op.m.| 60 | — 24 55°9 f i 4 
5 0 | Go | = ad a7a|y7! 130 | 91202] 1-0156 
Needle, R L (4). 
Aberdeen ...| July 19| 4 Opa] 63) — 7 35:2) 72 27-6 | 1:0056 | 1-0270 
Lerwick......, — 25] 3 30p.m.| 54 ]— 4 52:2 
— 26) 2 0 55 |— 4 51:0) +73 44:9 | 1:0159 | 1:0365 
3 0 55)/— 5 0-0 
Kirkwall......| Aug. 1] 1 30r.m.| 61 |— 4 55°6 ‘ é 
Pio ler lo 8 0 (73 204 | 10175 | 1-0381 
Inverness ...) — 14] 3 30p.m.| 60]— 5 14:7 . , 
230 | go |= B ida] t72 462 | 10180 | 10386 
Newcastle ...) — 29] 3 00p.m.| 61 |— 9 51:9 , E 
3B | er [a 9 ena] f 72 180 | 99787) 10175 
Stonehouse.../ Sept. 3/10 40 s.m.} 61 9 48-5 » , 
Noon "| 63 |= 9 507|t71 241 | 99713] 10173 
Jordan Hill..|) — 11] 2 Ovo} 64 |— 7 36:7 
3 0 62 |— 7 415 -aittaee 
as Ga ae | eases 72 20:0 | 1:0055 | 1:0259 
ll 0 638 |— 8 35 
Berwick...... — 17/11 30a...) 60 |— 8 19-9 . ae 
Noon | Go |= 8 1.0) $72 41-9 | 1-0050 | 1-0254 
Dunkeld...... — 20) 0 lipm.| 57 |— 7 37:2 ; ; 
| or la 7 areal p72 257 | 10063 | 1-0267 


MAGNETIC SURVEY OF GREAT BRITAIN, 161 


Collecting the results in one view, we have as follows: 


Taste LXI. 
Station. RL(.) RL (4). Mean. | Station. R L (3). 
Aberdeen ...| 1:0266 | 1:0270 | 1:0268 |! Dunkeld...... 1:0267 
Lerwick...... 1:0351 | 1:0865 | 1:0358 || Jordan Hill..| 1:0259 


Kirkwall ...| 1:0366 | 1:0381 | 1:0373 || Berwick...... 1:0254 
Inverness ...| 1:0370 | 1:0386 | 1:0378 || Stonehouse...} 1:0173 
Newcastle ...| 10156 | 1:0175 | 1:0165 


If we combine the results at these nine stations by the 
method of least squares, we obtain the following values: 
x= +°000080; 7 = — 000069; u = — 40° 38’; r = -000106. 
The mean geographical position is in latitude 56° 52! and lon- 


gitude 2° 45' W. 


§ 2. By the Method of Vibrations. 


Major Sabine’s Observations.—These observations were 
made in the summer of 1836; a detailed account of them is 
given in the Sixth Report of the British Association. Two 
cylinders, La and L 8, were vibrated at twenty-two stations in 
Scotland, between the 28th July and 18th September, during 
which interval the magnetism of the cylinders was proved to 
have been steady. The times of vibration at the several stations, 
reduced to a temperature of 60°, are inserted in Table LXIL., 
being taken from the Sixth Report of the Association. The 
values of the horizontal intensity are given in the table in re- 
lation to unity at Helensburgh ; and those of the total force to 
unity in London: the intensity at Helensburgh having been 
already shown to be as 10258 to 10000 in London. 


162 


Station. 


Helensburgh .... 


Great Cumbray { 


Loch Gilphead.. 
Tobermorie...... 


Loch Slapin..... 


Artornish......... { 


a 
a 
b 
b 
a 
b 
a 
b 
a 
b 
a 
b 
a 
b 
a 
b 
a 
b 
: e 0-9831 
: a| 253-53 
A b| 303-16 || 9 
: L b| 304-25 
Gaia? j Ces Ree L a| 254-48" | 0-9741 
Ope eae ererea aay ol CS L 6| 305:87 | 0:9729 
Aug. 25... L a\ 25272 | 0-9877 
Gordon Castle..| { ees alpen L 8| 303-29 | 0-9895 
Rhynie Aug. 26 60. «.{L a) 251-09 | 1-0006° 
a —  vsseeeees|L 6) 301-24 | 10031 
Aug. 28-29...... L a| 252-23 | 0-9916 
IMIFOT act seeseeest 6: da, 3|302:67 | 0:9936 
Aug. 30 ... a| 25096 | 1-0016 
Braemer ........: = | 30088 | 1-0055 
Blacsioite Aug. 31 a| 248-10 | 1:0249 
pd CEE Pt b| 297-69 | 1:0272 
Sept. 1 a| 251-26 | 0-9992 
Newport ....+..+. { Pr 5130172 | 0-9998 
: Sept. 3 a|250:79 | 1:0030 
Kirkaldy......... ‘Jy 2/30087 | 10055 
Sept. 6 a| 247-56 | 1:0293 
Melrose ......... Pt @ atch eas | 296-85 | 1:0330 
Dryburgh ...... Sept. 7 a} 247-20 | 1:0323 
Panes Sept. 16 a| 252-57 | 0-9889 
ceric =. b| 30315 | 0-9905 
Sept. 17 a| 249-33 |1-0148 
Campbelton......| 4 sia 3/299:05 | 1-0178 
Sept. 18 a|247°68 | 1-0283 
Loch Ryan...... { : 6| 297-06 | 10815 


EIGHTH REPORT—1838. 


Taste LXII. 


& | Time of | Horizontal Inten- 
fi Vibration,| sity, Helensburgh caer 
4 


— 


oye 72 


1-0087 |72 
10106 |72 


Date. Therm. 60. = 10000. 
1836. s 
July 28—Aug. 2)L aj) 251-05 
Sept. 18-14......)L. a| 251-27 f| 10000 
July 28—Aug. 2|L 6} 302-08 1-0000 
Sept. 13-14...... L 6| 301°33 
July 30 ......... L a} 249-82 | 1:0108 
— 300-71 | 1:0066 
249°75 |1:0113 
300°22 | 1-0099 


254:34 | 0:9755 
805°46 | 0:9752 
25450 | 0:9740 
305°04 | 0:9782 
252'57 =| 0:9866 
303°75 | 0:9889 
250°32 | 1:0035 
30117 | 10067 
25334 | 0:9829 
804:00 | 0:9849 
253°11 


}o975s 73 
}os761 73 
\o-os7 72 
}1-0051 72 
}o-vss9 72 


0:9850 |72 
69 


}o-9735 72 
| 0-9886|72 
}1-0018 72 
}o-vo26 72 
} 1-035 72 
} 1-0260 71 
}o-9995 72 
}1-0042 72 


} 10311 71 
71 
}o-9s97 72 


| 10163 71 
}1-0299 71 


162 


01:2 
07:7 
07-7 
02:2 
42-9 
172 
40-4 


46-5 


55°6 
40:9 
25°7 
22-0 
14:2 
54:8 
175 
11:0 


37 
33°7 
23 


56:0 
43°4 


Total 
Intensity. 
London 
= 10000. 


1:0258 


10203 | 
1-0279 | 
1-0492 4 
1-0446 | 
1-0380 | 
1-0315 | 
1-0315 | 


1:0385 | 


10353 | 
1:0371 | 
1-0358 | 
1-0281 | 
1-0270 | 
1-0319 | 
1:0260 
1-0247 | 


10208. 
1-0191 | 
1-0210 


1:0232 
10254 


“MAGNETIC SURVEY OF GREAT BRITAIN. 163 


Omitting Tobermorie, for the reasons assigned in page 157, 
and combining the results at the other twenty-one stations by 
the method of least squares, we obtain the following values: 
« =+°000080; y =—‘000118; « =—55° 46’; r = 000143. 
The mean geographical position is latitude 56° 35’, and longi- 
tude 4° 15' W. 


Captain Ross's Observations.—T hese were made in the sum- 
mer of 1838 with a cylinder (X) described in page 148. It was 
vibrated at Westbourne Green, near London, in June and 
July 1838, and again in December of the same year, having 
been used in the interval both in Scotland and in Ireland. The 
observations at Westbourne Green, showing that its magnet- 
ism underwent no change in this interval, are contained in the 
following table. 


Tasie LXIII. 


Time of | Mean Time of 100| Observed 


Date. Hour. | Therm. Niiteuban Vibrations at 60°. | Dip. 
1838. |h m a B s 
June ¥Y.../11 52 a.m.) 65 | 280-27 
mr ie achad 0 21pm.) 65 | 280-32 
June 5...)10 59.a.m.) 65 | 280-25 ; 
eee 04 pawl 68 | 28053 (| 2/999 
June 8...|11 49 4.m.| 57 | 279:78 
= shies 0 12pm.) 57 -| 279-63 
July 6...)11 05a.m.) 68 | 280:38 , DETAR 
ON a 11 27a.thl 70 |28040 |l genoa fe | oS 


July 12.../10 50am. 68 | 280-83 
= 0/11 124.m] 68 | 280-98 
; Noy. 30...{11 0 a.m.| 50 | 279-48 i 
— ascll1 27am] 51 279-52 ¢ ean 


The coefficient in the formula for the reduction to a mean 
temperature is ‘00017. 


Table LXIV. contains the observations with cylinder (X) at 
_ten stations in Scotland, and at two stations in the north of 
England, viz. Newcastle and Stonehouse. The values of the 
total intensity in the final column, relatively to unity in London, 
have been computed by means of the time of vibration of this 
eylinder in London shown in the preceding table. 


a 


va aad te Berk 


164 EIGHTH REPORT—1838. 


TasLe LXIV. 


Station. Date. Hour. | Therm. ast ee Corrected | Observed pie 
Vibrations.) Time. Dip. | = 10000. 
iy. 18) 2 10 4 |sap57) |. | SB 
Aberdeen ........ July 1 p.m.| 64 | 299°5 . : ‘ 
y a a 299-49 29937 | 72 27-6| 1-0292 
Lerwick .........\July 23) 2 52p.m.) 50 | 307°82 
24/11 124.m.) 54 | 809°35 
26\11 0 52 | 308-82 +| 309-27 | 73 44-9) 1:0386 
27/11 12 60 | 309-90 
28) 0 40 p.m.| 54 | 308-98 
Kirkwall......... July 31)11 504.u.) 56 | 304-92 
ug. 1/10 50 59 | 3805-12 
3/11 44 58 | 305:12 +| 305-31 | 73 20-4} 1-0403 
4\11 21 60 | 305-52 
6|11 28 57 | 805:08 
WICK ceccccoeeees Aug. 8/11 124.m.) 58 |305°32 | 305-43 | 73 19-9} 1-:0390 
Golspie ......+++ Aug. 10/1] 424.m.) 66 | 303-28 
11|11 27 63 | 303:48 }| 303-26 | 73 04:4] 1:0382 
12/10 28 62 | 303°58 a 
Inverness ....+++. Aug. 13] 1 32p.m.} 58 | 30038 5 4 
E Ailaac es eis enon 13 30051 | 72 46-0] 1-0395 
Newcastle ...... Aug. 29/83 a.m.) 52 | 290-9 
80)|10 40 59 | 291-28 +| 291-41 | 71 13-0}. 10167 
11 15 60 | 
“ |Stonehouse ...... Sept. 1] 0 46P.m.) 57 | 292°8 
PB) Law| 60 [292-70 ¢| 29286 | 71 24-0) 1-0163 
Culgruff ......+4 Sept. : Cae P.M. - ee 
10 18 a.m. 293° 
810 43p.mi 52 | 293-35 [| 29350 | 71 35:7) 1-0219 
9| 9 47a.m,| 51 | 293-00 
Jordan Hill......|Sept. 11] 5 27 p.m.} 60 | 298-18 
12/11 0 a.m.| 56 | 298-22 +| 298-39 | 72 20:3} 1-0289 
13| 8 54 60 | 298°55 
Berwick ..s..0«.[Sept. 17/94 a.m| 56 | 293-83 = aS ie 
ae a 393-62 ¢ 294-02 | 71 41-9] 1-0241 
Dunkeld ......... Sept. 20/10 224.m.] 58 | 298-52 : e : 
21110 19 48 |998-39 7| 29892 | 72 23:1) 1-028] 


If we combine these twelve results by the method of least 
squares, we obtain the following values, viz.: 2 = + 000091 ; 
y = —'000086 ; w= —435° 32’; r=:000125. The mean geo- 
graphical position is 56° 56’ N. lat., and 2° 58’ W. long. 


MAGNETIC SURVEY OF GREAT BRITAIN. 165 


If we collect in one view the values of « and r which have 
been obtained from the several series in Scotland, we have as 
as follows: 


TasBLeE LXV. 
bale san Gesgeaphieal Values of 

Observer. Method. Stations. 

; Lat. Long. u - 
Sabine ...|Statical ........++. 19 | 5692 | £01 | —52 15] -000136 
Ross...... Statical .......ce008 9 56 52 | 245 | —40 38] -000106 
Sabine ...|Hor. Vibrations.... 21 56 35 415 | —55 46) :000143 
Ross..... .|Hor. Vibrations.... 12 56 56 258 | —43 32 | -000125 


Regarding the values of u and r as entitled to weight pro- 
portioned to the number of stations of which each is the re- 
presentative, and giving equal weight to a result by each me- 


_thed, we obtain —50° 02’ and ‘000132 as the mean values of 


u and r derived from the Scottish series, and corresponding to 
the central geographical position in 56° 40’ N. lat., and 3° 30! 


_W. longitude. 


Section IIJ.—IRevanp. 


(By the Rev. H. Luoyp.) 


1. Method of Vibration. 


The body of results obtained by this method in Ireland has 
received some valuable accessions, and undergone other impor- 
tant alterations, since the publication of the Irish Magnetic 
Report. We shall consider these under the following heads. 
1. Additional observations; 2. Corrections of the results pre- 
viously obtained ; 3. New determinations of the intensity at the 
base stations. 

Additional Observations.—These consist in a comparison of 
the intensity at London and Dublin, made by myself in the year 
1836; a comparison of Dublin and Banger, made by Major 
Sabine in the latter part of the same year; a comparison of 
London and Dublin, by the same observer, in the year 1838; 
and a complete series of observations made by Captain James 

VOL, VII, 1838, M 


¥ 
Sp 


166 EIGHTH REPORT—1838. 


Ross, in the year 1838, at twelve distinctstations throughout 
the island. This latter series, forming in themselves a complete 
body of results, will be considered separately. The additional 
observations made by Major Sabine and myself are contained in 
the following table*. 


TasLe LXVI. 
Cylinder L (a). 


Station. Date. Hour, Time. Temp. Corr. Time. 
ies A a x O4 ; 
April 11, 1886.) 11 14 243-56 56-2 243-76 
Dublin — 1 Hes 8S 243-96 61:0 243-88 
hoe a bi ll 14 243-50 56°5 243-69 
Mean. 243-67 57°9 243-78 
April 19 12 ll 236-02 59°5 236-04 
Tantan — 2) es | 235°94 60-0 235-93 
were — 22 ll 51 236-23 61-5 23613 
Mean. 236-06 60°3 236-03 
May 7 12 30 234-96 57°6 244-10 
Wuahling sc. — 9 12 6 243-90 61:0 243-83 
Mean. 243-93 59:3 243-96 
July 24,1836.) 9 0 243-47 59:0 243-53 
Dubliniwessss — 25 7 30 243-11 55:0 243-41 
Mean. 243-29 57:0 243-47 
Sept. 21 9 45 246-53 48-6 247-20 
Bangor ...... — 2) 10 15 246-72 49:0 247-39 
Mean. 246-62 48°8 247-30 
Oct. ~S 10 10 243°25 45-0 244-16 
— 3 Zs +8 243-22 47-0 244-01 
Dublingen-+.: — 3 2 30 243-09 48-0 243°82 
—_ 4 1 45 243°18 515 243-70 
Mean. 243°18 47-9 243-92 
if June 1, 1838, 11 37 236°27 62-0 236°15 
London ...... se | ll 56 236715 62-0 236-03 
ii Mean. 236-21 62-0 236-09 
Aug. 6 4 12 246-30 66:0 245-93 
Ti nhins asec: — 3 44 245-81 63:0 245-63 
Mean 246°05 64:5 245-78 
Oct. 13 3. ~C«*O0 237-77 39°0 239-01 
London ...... — 13 3 16 237°81 40:0 238-99 
Mean, 237°79 39°5 239-00 


* The details of the comparison of Bangor and Dublin have been already 
printed in the Scotch Magnetic Report: they are reprinted here, so that all the — 
results obtained in Ireland may be seen in connexion. 


MAGNETIC SURVEY OF GREAT BRITAIN. 167 


TasLe LXVII. 
Cylinder L (4). 


Station. Date. Hour. Time. Temp. Corr. Time. 


1836. | 5 ™ : AS : 

April11 | 10 48| 292-93 | 565 | 293-16 
— 12 |10 44| 29350 | 592 | 29353 
— 15 | 10 48| 293-09 | 568 | 293-29 
Mean. 29317 | 57:5 | 293-33 
April19 | 11 36 | 28417 | 61:0 | 284-08 
— 21 | 1 38) 28444 | 605 | 284-38 
— 92 | 11 22] 98427 | 605 | 284-21 
Mean. 284-29 | 60:7 | 284-22 
May 7 | 12 6| 29295 | 580 | 293-08 


Dublin ....... 1 — 9/)11 40 293-43 61:0 29334 


London ...... 


Mean. 293°19 59°5 293°21 


30 293:22 59:0 293°29 
0 292-25 54:0 29269 
40 292-57 55°5 292-90 
292-68 56:2 292-96 
295-28 49°6 296-04 
25 291-02 44-5 292-15 
45 291-24 44°5 292°37 
55 291:37 49-6 292°13 
15 291-73 53°5 292-20 
Mean. 291:34 48:0 292-21 


™m 
Oo 
as] 
or 
i) 
— 
_ 
= bh O Oe mom 
_ 
i=) 


ACaARE — —/|ll 4 284-17 62-0 284-00 
Mean. 284-17 62:0 284-00 
| Aug. 6 3 42 292°88 67:0 292°37 


Junel,1838, 10 21 284-17 62:0 284-00 
London 


— 8 1 42 292°48 63-0 292-26 
Mean. 292-68 65:0 292°31 


Correction of the Results —The first correction that seems 
to be required is in the series of results obtained in the North 
of Ireland, in the autumn of the year 1834. On a comparison 
of the times of vibration of cylinder L (4) in Dublin, at the com- 
mencement and end of that series, it will be seen that the mag- 
net sustained a loss of force; and an attentive examination of 
the other parts of the series shows that this loss occurred im- 
mediately previous to the final observation in Dublin. This 


fact will be seen very evidently by means of the following table, 
which contains the corrected rates of the two cylinders, and the 


deduced values of the intensity compared with the intensity in 
Dublin at the time of the initial observation. The results ob- 
tained with the two cylinders present a very close agreement, 
except in the final observation. 


M 2 


168 EIGHTH REPORT—1838. 


TaBLeE LXVIII. 


L (a). L (6). 
Station. | 
Time. Intensity. Time. | Intensity. 
s s 
Dublin ............|  248°90 1-000 292-74 1-000 
Armagh.........00. 246°88 ‘976 296-40 975 
(CAPM sc ccseessccusss 248-10 “966 297-71 “967 
Strabane ......... 248-51 963 298-22 ‘964 
Enniskillen ...... 248-42 964 297°83 -966 
Dublin ............ 243-92 1-000 293-62 994 


Hence, instead of comparing the other results of cylinder L (4) 
with the mean of the initial and final observations in Dublin, 
they are to be compared with the ¢vi¢ial observations alone; the 
final observations not being comparative with the rest of the 
series. The loss of force sustained by the cylinder L (d) being 
‘006, the amount of the correction is 

dh = —:'003 xh; : 
h denoting the horizontal intensity, as originally deduced, and 
5A its correction. 

A correction of a similar kind (that is, depending on the rate 
of vibration at the base station) seems to be required also in the 
series of results obtained in the west and south of Ireland in 
the summer of 1835. In reducing the observations of this series, 
I had taken as the Dublin time, the mean of the initial and final 
times, without regarding the number of separate observations ; 
but, if we suppose the difference between these times to be owing 
to errors of observation, or to any fluctuating source, it is ma- 
nifest that we should take, as the Dublin time, the mean of the © 
separate results themselves. This seems to be the proper course 
in the present instance. The initial time is the result of a sin- — 
gle observation only, and that taken under the disadvantage of 
an unusually high temperature ; so that the difference between — 
it and the final time (which difference is nearly the same for the 
two cylinders) is probably due either to the irregular fluctuations 
of the horizontal intensity, or to error in the coefficient of the 
temperature correction. 

It is easy to determine the amount of the required correction, 
If T denote the time of vibration at any station, T’ that at the 
base station, and A the ratio of the horizontal intensities, 


Te 


h = Te . 


MAGNETIC SURVEY OF GREAT BRITAIN, 


Hence if 5'T’ denote the small correction in the value of T’, and 


5h the corresponding correction of h, 


oh  285T 
Si ila 
To apply this in the present instance, we have 
L (a) 
s 
Mean of separate observations . 243°43 
Mean of initial and final results. 243°29 
Correction of T’,orédT’. . . . +0°14 
Resulting value of 2 dieecht sicisarto Oe 


L (4) 
s 
293°18 
293-06 
+0712 


+ ‘0008 


The corrections here obtained are applied to all the results 
of the series (Aug. 19, to Sept. 15, 1835) in Table LX VIII. 


 Patlues of the Intensity at the Base stations.—The following 


is a summary of the comparisons of the horizontal intensity in 
London, Dublin, and Limerick, as contained in Table LXIX. 


Horizontal intensity in Dublin, referred to London : 


July, August, 1835. Cyl. Re 
— — — — Rd 
Sept. Oct. Nov. 1835. — La 
—- —- — — — Lh 
; April, May, 1836. — La 
- —_—_ — — — Lb 
June, Aug. Oct. 1838. — La 
—- —- —- — — Lb 


Mean....... 


Int. 


Hue We wet al 


"9456 
"9421 
°9354 
"9348 
"9367 
"9392 
°9340 
"9440 


°9390 


; Horizontal intensity in Limerick, referred to London : 


oy July, 1835. — Sh 
at July, August, 1835. — Re 
July, August, 1835. — Rd 


Mean. outs s 


July, Aug. Sept. 1834. Cyl. S4 Int. 


Hot i tl 


*9396 
"9470 
°9461 
°9513 


*9460 


169 


‘oi ae 7 


170 EIGHTH REPORT—1838. 


Horizontal intensity in Limerick, referred to Dublin : 


October, 1834. Cyl. La Int. = 1:0075 
— — — Lb’ — =1:0015 

July, Aug. 1835. — Re — =1:0005 
—_- — —_ — Rd — =1:0098 

Aug. Sept. 1835. — La — =1:0039 
— — — — LA — =1:0055 

Nov. Dec. 1835. — La — =1°:0001 
— — — — Lb — =1:°:0021 
Mean’. . die’. ‘0.0 s55:0 = T0039 


Now, the comparison of Dublin with London and with Li- 
merick being each the mean of eight separate comparisons, 
while that of Limerick and London is deduced from four only, 
we have (see Fifth Report, p. 133.) 


Jo 2 Bie, 
Hence the formule of page 134 become 
bentarayae YF aheey aD 
but a='9390, b='9460, c=1-0039; 


¢= 251-0075, c,—c="0036 : 
and, substituting these values, 


8a=+°0009, sty=—*0017; 
%=A4+0x7='9399; 
y=bh+dy='9443. 


The numbers in the 6th column of the following table are — 
deduced from those of the 5th, by multiplying by one or other 
of these numbers, according as the station has been compared, — 
in the first instance, with Dublin or with Limerick. 

It will readily appear, from the principles laid down in pages 


95 et seq., that the weights of these determinations are ex- 
pressed by the formule 


BC ec? AC 
PTL BeEO Var Ad Ce 


MAGNETIC SURVEY OF GREAT BRITAIN. 171 


Now, A=C=8, B=4; substituting these values, and those of 
a, b, c, given above, we have 


X=10°8, Y=8'2; 


the weight of a single comparison being unity. 


TasBLe LXIX. 


Intensity of the Horizontal Force. 


Hor. Int. 


Station. Date, Cyl. | No. Hor. Int. (London=1.) 
1834. 
Limerick .........006 July, Sept. Sé 5 ‘9396 
London........ sss. Aug. 20-27 S6 | 20 1:0000 
Limerick ..........0. Sept. Oct. So 3 1:0000 
: — 9, Oct. 8 La 2 9900 | “9443 
re, 2S 8 > aes 3 0000 
Ballybunian ......... — 16 Sé 1 1-:0010 
ae ALS, La 1 aes “9441 
Ser, Lé 1 1:0029 
Glengariff............ — 27 Sb 1 1:0110 
yp La 1 10110 “9511 
pa Lé 1 “9997 
Killarney ........ AE Oct. 4 S6 1 1:0039 
pate” il La 1 10086 9503 
abe eT Lé 1 1:0066 
Kiltanon .........006 Son 2 Sob 1 9983 *9497 
Templemore......... — 1% Soé 1 1:0404 “9524 
Clonmel ............ — 19 Sob 1 10092 9530 
Fermoy ............00. Dec. 2 S6 1 1:0157 9591 
Limerick ............ — 10 So 1 1-:0000 *9443 
Dublin ............... Oct. 10-28 La 6 1-0000 +9399 
hl Lb 4 1-0000 
| Limerick ............ — 8 La 1 1-0075 9441 
ig denne Lb | 2| 10015 
| Carlingford ......... — 13 Lo} 1 “9868 9275 
Armagh........... Sele — 14,15 La 2 ‘9761 F 
5 — 14,15 Le | 2| 9754 oli 
ey Colerain.............0. — 18, 20 Lo 2 ‘9870 9277 
ai Carn Secvcescccesvecees — 21 L a 1 -9665 -9086 
melt — 21 Lb 1 -9669 
Strabane ......s..0.s — 23 La 1 ‘9633 9056 
— 23 Lb 1 9636 
Enniskillen ......... — 24 La | 1 ‘9640 9070 
— 24 Lo 1 ‘9661 


172 EIGHTH REPORT—1838, 
Station. Date. Cyl. | No.| “Hor. Int. Heethial 
1835. 
Hondon\scr.ssecesseees July 47 $b | 12 
July 8-20 Re | 25 
Aug.28-31 Rd | 14 
Limerick ....... seeee| July 27, 28 Sb 2 
— 27-29 Re | 10 1:0005 
— 29-31 Rd} ll 10098 
PDL Nel icaccessesees Aug. 16 Re 3 1:0000 
— 14 Rd| 3 1-0000 
Markree .....sseeee. — 19 Re 3 9531 
— 19,20 Rd 3 9558 
Wblin, 5 ..ces cs esaser Aug.19 La 5 1-0000 
Sept. 12-15 Lb 4 1-0000 
Markree .......0e0e. Aug.21 La 1 9580 
— 21 Lé 2 9566 
(Eallitiatscss-corensness — 22 La 1 9545 
— 22 Lob 1 9517 
Belmullet ..........+. — 24 La 1 *9497 
— 24 Lb 2 “9454 
ACYL. sucssarvesceane — 25 La 1 9576 
— 25 Lé 1 9552 
Leeman ...scssesenenee — 26 La 1 9621 
— 26 Lé 1 9636 
Oughterard ......... — 27 La 1 9777 
— W Lb 1 9781 
ENNIS... :ccovcssene aes — 28 La 1 “9995 
— 28 Lb ] 9977 
Limerick .........+.. — 29 La 1 1-0039 
— 29 Lb 1 1-0055 
Cork ccncass+s¢suasaes — 31 La 1 1-021] 
— 31 Lob 1 1-0294 * 
Waterford ............ Sept. 1 La 1 1-0125 
— 1 Lé 1 1:0115 
Broadway ...++++0s0+ — 2 La 2 1-0215 
— 2 Lob 1 1-0246 
Rathdrum..........+. — 3 La 1 1:0013 
ees: Lé 1 1:0035 
Wondoni .csscedepssusn Sept. 19-22 La 6 
Oct. 23, 24 Lob 7 
Wublin 5. .ccenees eoeee| Sept. 12-15 La 7 
Nov. 5, 6 Léb 6 
Dublin) ...2..pecevesp Nov. Dec. Jan. La 8 1-0000 
Noy. Dec. Jan. Lob 7 1:0000 
Limerick .......... Dec. 19-23 La 3 1:0001 
— 19-23 Lb 3 1:0021 
Wondon)...:<.sqecssees Apr. 19-22 La 3 10000 
1836. Lé 3 1-0000 
Dublin’.<.vssaeccees Apr. 11-15 La 5 9367 
May 7-9 Léb 5 9392 


* Disturbing influence suspected in this observation : the result has been ac- 
cordingly omitied in deducing the number in the last column. 


MAGNETIC SURVEY OF GREAT BRITAIN. 173 


Station. Date, Cyl. | No. Hor. Int. Peel cent 
1836. 

Dublin ...... Bea eens July 24, 25 La 6 1-0000 -9399 

Oct. 3, 4 Lob 7 1-0000 

Bangor ......s0008 Read Sept. 21 La 2 -9710 
a = Oy La| 1|  -9768 vas 
London.........008 os June 1, Oct. 13,1838} La 4 1-0000 
—— Lé 2 1:0000 
| Dublin ...........066 _ Aug.6-8 La} 2 9340 
— 6-8 Lé 2 9440 


_ The following table contains the resulting values of the hori- 
zontal intensity, those of the total intensity thence deduced, 
and the latitudes and longitudes of the stations. The values of 
the dip employed, in deducing the total from the horizontal 
intensities, will be found in Table XXXVI. 


TaBLE LXX. 


Station. Lat. Long Hor, Int. | Total Int. 
Oo 7@¢ Oo 74 
Mb g. oeeceacwssens des 53 21 6 16 9399 1:0203 
Limerick ..........+000. 52 40 8 35 9443 1-0260 
Ballybunian ............ 52 30 9 41 9441 
Glengariff............00 51 45 9 31 ‘9511 1:0283 
Killarney ...... .....50. 52 3 9 31 9503 1:0300 
Kiltanon .........secees 52 52 8 43 9427 1:0318 
Templemore............ 52 47 7 48 9824 
Clonmel] ............005 52 20 7 41 9530 
Fermoy .......essesceseee 52 7 8 16 9591 1-0259 
Carlingford ........... 54 2 6 ll 9275 | 1:0279 
Armagh......scccescovees 54 21 6 39 9172 | 1:0272 
Colerain .............4. 55 8 6 40 9277 | 1:0250 
WEAR s aapnnsceworsndcoters 55 15 7 15 9086 | 1:0346 
Strabane ..........0.00e 54 49 7 28 9056 | 1:0303 
Enniskillen ............ 54 21 7 38 ‘9070 | 1:03821 
Markree  ............008 54 12 8 26 8998 | 1-0316 
Sete Ballina ........ce.cscccce 54 7 9.7 8959 | 1:0313 
Belmullet .............0. 54 138 9 57 8906 | 1:0274 
SCRA ae a 53 56 9 52 8990 | 1:0308 
Leenan ........ desienctea ds 53 386 9 40 9051 
Oughterard ............ 53 26 9 18 9191 
BINMIS af selebakces ce ovs 52 51 8 58 9386 1-0270 
(CT oe a ee 51 54 8 26 9597 1-0236 
Waterford............0. 52 16 7 8 “9512 | 1:0209 
Broadway .............68 52 13 6 24 9615 1:0194 
Rathdrum........ aeebene 52 55 6 14 "9422 | 1-0137 
PAU POD cen vsesiessceeees 54 39 5 42 “9154 | 1:0266 


Of these results, those obtained at Templemore, Carlingford, 
and Colerain, are not included in the computation of the lines, 


174 EIGHTH REPORT—1838. 


being manifestly affected by disturbing aetion. The disturb- 
ance at the two latter stations is obviously due to the presence 
of trap rocks. 

In deducing the lines of total intensity, I have been guided 
by the principles laid down in page 95 and seqg., and have ac- 
cordingly assigned double weight to the results in Dublin and 
Limerick, the weight of each of the other comparisons being 
taken as unity. The results of the computation are as follows : 


L=1:0268, M=-+:0000748, N=-+:'0000501 ; 
u= —33° 48/, r=:0000900; 


L denoting the intensity at the central station (Lat.=53° 21', 
Long. —t he 0’), the intensity at London being unity; M and N 
the increase of the intensity, corresponding to each geographical 
mile of distance in the direction of the two coordinates ; 7 the 
angle which the isodynamic line, passing through the central 
station, makes with the meridian; and 7 the increase of the 
intensity in the direction perpendicular to that line. 

The lines of horizontal intensity rest upon a somewhat 
broader basis, there being four stations where the horizontal 
force was observed without the dip. In deducing them, I have 
given a weight of ¢wo to the results obtained at Dublin, Lime- 


rick, and Markree, the weight of each of the other determinations ~ 


being unity. We find, accordingly, 


L='9290, M=—-000190, N=—-000368; 
u= —62° 40’, r=*000414. 


Captain Ross’s observations are contained in the following 
table. They were made in the autumn of the year 1838, with 
a single cylinder, designated as R(X) in the following pages. 
The stations are twelve in number, and are distributed uniformly 


over the island. The permanency of the magnetism of the i 


cylinder during this series, and its time of vibration at West- 
bourn Green, near London, have been already shown in 


Table LXITI. 


er 


“MAGNETIC SURVEY OF GREAT BRITAIN. 175 


TasBLte LXXI. 
Mean 
Station. Date. Hour. | Therm. Tce Temperature 
1838. jh. m. A S. s 
Waterford seeeee eeeessees Oct. 3|42 3P.M. 56 287-18 287°45 
— 4/1017 a.m.) 56 | 287-35 
MOG ticlevcreNaeses ass savese — 6/5 82p.m.| 54 | 285-438 
— 7/11 404.m.| 63 | 286-47 286-20 
— 8/0 38p.m.| 54 | 286-08 
Valencia Island ...... — 12)11 26a.m.| 54 | 286°83 287-07 
— 13/10 264.m.| 53 | 286-68 
Killarney ........seceee — 17/11 2am.| 52 | 286-75 
— 18/2 38a.m.| 52 | 286°65 
— 19/10 22 a.m.| 58 | 286-87 
Limerick ......... aches — 22/11 8a.m.| 60 atk 33 
Noon 62 | 288-47 if 
— 23/8 4la.m.| 54 | 287-98 sees 
11 Ga.m.| 57° | 288-18 J 
Shannon Harbour ...| — 26] 9 35 a.m.| 50 | 290°35 290-88 
10 14 4.m.} 52 29052 
RIDING cssysevescencesens — 29/11 28a.m.| 50 | 288-82) 
11 5l a.m.| 50 28878 289-12 
— 30| 7 59am 40 | 287-95 
8 30 4.m.} 41 2598 | 
Armagh..... abicivest sues Nov. 1] 4 32 p.m 42 | 292- .O% 
5 = 2) 8 dtam.] 43 | 29217 as 
Londonderry ......... — O/ll 4lam 52 5°18 A 
a — 6/11 1384. 51 | 295-07 298-55 
Markree ..........00005 — 10/11 17 a.m 44 | 294-33 295-16 
— 11/4 18pm.| 43 | 294-33 
Westport ........ssesees — 13/0 32p.m.| 45 | 293-97 294-66 
— 14/11 154m 42 | 293-70 
Edgeworth’s Town...) — 19| 0 15 p.m 45 | 291-00 292-04 


20 |10 59 a.m.| 44 | 291-28 
a 
i; : 
The following table contains the resulting values of the hori- 
_ zontal intensity ; those of the total intensity thence deduced, 
and the latitudes and longitudes of the stations. The dips 
_ employed in deducing the total from the horizontal intensities, 
_are given in Table XX XIX; the London dip used in the com- 
putation is the mean dip at Westbourn Green (Table III.), 
reduced to the mean epoch of the present series. 


176 EIGHTH REPORT—1838. 


Taste LXXII. 


Station. Lat. Long. Hor. Int. | Total Int. 
Oe D. eZ 
Waterford .......cscscses 52 16 7 8] +9493 1-0205 
@ork preter. cacetse eS 51 54 8 26 | -9576 1:0239 
WalenCla” scccaccesctssec 51 56 10 17 | -9517 1-0285 
WMallarney *scscesscssecees 52 3 9 31 9511 10271 
Limerick ............06. 52 40 8 35 9435 1-0262 
Shannon Harbour 53 14 7 52} -9270 10287 
Dublitt, .svcascce.ces occ 53 2] 6 16 | -9383 1-0205 
ARIMA GN Se teres oc-.cces~ 54 21 6 39 | -9140 1-0296 
Londonderry............ 55 (0 7 20 | -8979 | 1-0314 
Markee i sc2..cocesess 54 12 8 26 | -9003 | 1-0321 
Westport .........c0000. 53 48 9 29 9034 1:0345 - 
Edgeworth’s Town...| 53 42 7 33 9196 1:0264 


In deducing the values of L, M, N, equal weights have been 
assigned to all the results. The following are the values ob- 
tained for the lines of total intensity. 


L=1:0276, M=-+-0000858, N=-—-0000671; 
u=—38° 0!, r=+000109. 


For the lines of horizontal intensity, we find 


L=:9269, M= —-000138, N=—-000379; 
u=—70° 0', r='000403. 


2. Satical Method. 


Additional Observations.—The observations made according 
to the statical method since the printing of the Irish Magnetic 
Report, consist of my own observations in London and Dublin, 
in the year 1836; Major Sabine’s observations in Limerick, 
Dublin, and Bangor, in the autumn of the same year; a com- 
parison of London and Dublin, by the same observer, in the 
year 1838; and a series of observations, at eight distinct sta- 
tions, made by Captain James Ross, towards the close of the 
latter year. The details of my own observations, and of those 
of Major Sabine, are given in the following tables. Captain 
Ross’s observations, as before, will be considered separately. 


: 


Needle. | 
Dublin 
od 
4 {London 
ov 
s 
& 
vA 
Dublin 
|Dublin 
3 London 
o 
3 
o 
a 
Dublin 


MAGNETIC SURVEY OF GREAT BRITAIN. 


TasieE LXXIII. 


Mr. Lloyd’s Observations, Needles L3 and L 4. 


Station. 


ereeeee 


Date. Hour. Temp. Angle. 
h m 
° jo Py 2 

apa 11, 1836.| 12 18 57-5 | —15 23-4 
1b 12 30 53:0 |—15 3-6 
‘Mean 12 24 55-2 | —15 13-5 
April 19 1 0 55°8 | —18 43-5 
— 21 2 58 58:5 |—18 47°6 
— 22 12 30 592 |—19 60 
Mean. 1 29 57°38 | —18 52-4 
May 7 1 32 57-2 | —15 52:5 
ae 1 25 60:0 | —15 52°5 
Mean 1 28 586 | —15 52-5 
Aug. 5 3 50 61°38 | —15 53:8 
— 2 35 67°38 |—16 9-2 
Mean 3 12 64:8 |—16 1:5 
April 11,1836.) 12 43 57°38 | —18 26-4 
— 15 12 #68 535° | —13 21-0 
Mean 12 25 55-6 | —13 23-7 
April 19 1 28 568 | —16 319 
— 21 2 37 58:5 | —16 59-9 
— 22 12 14 60°5 | —16 57°6 
Mean. 1 26 58:6 | —16 49-8 
May 7 1 10) 565 |—13 22°5 
— 12 50 60°5 | —13 18-4 
Mean 1 0 58:5 | —13 20-5 
Aug. 5 3 28 61:8 | —13 43°6 
— 2 10 665 | —13 34-4 
Mean 2 49 64:2 | —13 39:0 


1 


7 


178 EIGHTH REPORT—1838. 


Taste LXXIV. 
Major Sabine’s Observations, Needle S 2. 


Station. Date. | Temp. Angle. 
Or Sf ie} é 

July 15, 1836.) 58-0 a oe 

rule —. 15 570 | — : 
Limerick coccee oes 16 59-8 RE\ I; 21:5 
Mean 583 | —17 26-7 
July 22 | 54:0 “ als 

2 ==! 22 560 | —18 28- 
Dublin eeccces i 93 575 _18 22-7 
Mean. 558 | —18 27°5 
Bangor ......... Sept. 21 | 500 | —18 55-9 
Dublin .......... Oct. 4 49:0 | —19 53:3 
(| June 1, 1837.| 58:0 —17 52-1 
— 58:0 | —17 566 
July 25 700 |—18 7:4 
— 2 730 |—18 05 
Mean 64:8 | —17 59-2 
London ...... Nov. 14 | 500 | —17 128 
— 14 50:0 | —17 14:7 
ca 1G | 37:0 | —16 53:7 
— 16 37:0 | —16 52°6 
— 16 370 | —-17 O06 
Mean 42:2 | —17 (29 
July 31, 1838.| 65-0 | —14 29-1 
— 3 65:0 | —14 ae 

F Aug. 2 66:0 | —14 19 
Dublin ....... us 67-0 | —14 295 
— 3 67:0 | —14 26-0 
\| Mean 66-0 | —14 26:8 
Oct. 12,1838.| 48:0 | —17 32-1 
— 48:0 | —17 33-9 


London ...... — 13 465 |—17 183 
| Is 465 | —17 26:8 
Mean. 47-2 | —17 27° 


Correction of the Results—The only correction which seems 
necessary in the results already recorded is that due to the ef- 
fect of temperature upon the needle S 2, the temperature-cor- 
rection of that needle having been obtained by Major Sabine 
subsequently to the publication of the Irish Magnetic Report. 
This correction is small, the coefficient in the logarithmic for- 
mula being only ‘000024*. The corrected results are given in 
Table LXXV. 

As the expression of the intensity deduced by the statical 
method is a function of the dip, as well as of the inclination of 
the needle when loaded, it may be necessary to show that the 
changes in the dip-corrections of the needles (page 104 and seg.) 


* Sixth Report, p. 108. 


_ . ] 
¥ 4 ? 
J 


on 


MAGNETIC SURVEY OF GREAT BRITAIN. 179 


can have no sensible effect upon the deduced values of the in- 
tensity. 
The ratio of the intensity at any station to that at the base- 
station being denoted by ¢, we have (Fifth Report, p. 147,) 
gu cos @ sin (6, — 4) 
cos 0, sin (6 — 6) * 


Hence, supposing 6 and 6, to vary by any small and equal amount, 


A6, the corresponding variation of ¢ will be expressed by the 


formula 


“S = {cotan (6, — 9,) — cotan (6 — 6)} AS 


_ Now the quantity, A 5, is very small, and (where the stations 


are not widely separate) the coefficient by which it is multi- 
plied is likewise small; for such, stations, then, the result- 


A¢ 


tical values of 6, 6,, 0, 0, for the extreme stations of the present 
series, it will be seen that the correction does not affect the fourth 
place of decimals. 


ing value of is inconsiderable. On substituting the nume- 


Values of the Intensity at the Base stations.—The following 
is a summary of the comparisons of the intensity at London, 


~ Dublin, and Limerick, as contained in Table LXXV. 


Intensity at Dublin, referred to London : 


Aug. Sept. 1834 . . . Needle L4 Int. = 1:0194 
Sept. Oct. Nov. 1835 . — L4 — = 1:0212 
April, May, 1836. . . — L3 — =1°:0194 
April, May, 1836. . . — L4 — =1:0189 
June 1837, Oct. 1838 . — 8s2 — = 1:0183 

Mean = 1:0194 


Intensity at Limerick, referred to London : 
June, July, Aug. 1834 . Needle L 4 Int. = 10262 
Intensity at Limerick, referred to Dublin : 


Aug. Sept.1835 . . . — L4 Int. = 1-0030 
Me tooGe si — 82 — = 1:0062 


Mean . . =1°0046 
_ We have therefore (Fifth Report, p. 148), 
a = 1:0194, b = 1:0262, c = 1:0046; 


7 


180 EIGHTH REPORT—1838. 


Substituting these values in the formule of page 134 (Fifth Re- 
port), we find 
Sa = + :0003, Sy = —-0012; 

v=a+t dr =1:0197; 

y =h + Sy = 1:0250. 
The results in the 6th column of the following table are deduce 
from those of the 5th, by multiplying by one or other of these 
numbers, according as ‘the station has been originally compared 

with Dublin or with Limerick. 

The weights due to the preceding determinations are given 
by the formule of page 170. Substituting the numerical values 
of A, B, C, &c., we bik 

a fie Y= o4 
the weight of asingle rece being unity. Adopting the near - 
est whole numbers, we may consider the deduced value of the in- 
tensity in Dublin as equivalent to the result of sia separate compa - 
risons; and that of the intensity in Limerick as equivalent to fwo. 


TaBLE LXXV. 
Intensity of the Total Force. 


Station. Date. Needle.| No. Intensity. pute 1 5) 
London.........+6 August, 1834.) L 4 3 1-0000 
Limerick .......0. June, July. —_ 3 1-:0262 
Dublin ............ Sept. 22—29, _— 4 1:0194 
Dublin ............ Sept. Oct. L4 5 1:0000 10197 

*Carlingford ...... Oct. 13. — 1 1:0166 1-0366 
Armagh............ — 14,15. —_— 2 1:0044 1-0242 
*Colerain ......... — 20. _ 1 9997 1:0194 
Garntesoccras:. cscs — 21. _ 1 1-0151 1:0351 
Strabane ......... — 23. — 1 10100 10299 
Dublin ............ Aug. Sept. 1835.) L 4 5 1-0000 1:0197 
Markree............ Aug. 21. _ 1 1:0091 1:0290 
Ballina ............ — 22, — 1 1:0077 1:0276 
Belmullet ......... — 24, —_ 1 1:0093 1:0292 
AICHIL Petes tees — 25, — 1 1-0096 1:0295 
Galway ..........+. — 28 — 1 1-0086 1-0285 
Ennis..........00e0 — 28. _ 1 1:0055 1-0253 
Limerick ......... — 29, — 1 1-0030 1-0229 
GCOrks civka ve scetees — 3i. _— 1 9992 1:0189 
Waterford ......... Sept. 1 — 1 +9966 10162 
Broadway ......... — 2 — ] 9976 1:0173 
Gorey.....csecsseees — 3 — 1 9933 1:0129 
Rathdrum ......... — 3 _ 1 9944 1:0140 
London ............ Sept. Oct. 1885.) L. 4 6 1:0000 
Bublin ............ Sept. Nov. — 7 | 10212 


* Evident local disturbance at these two stations. The district about Car-— 
lingford is intersected with trap dykes; Colerain lies within the basaltic field 
of the North East of Ireland, 


Station. Date. Needle.| No. 

Limerick ......... July, Dec. 1835.| S. 2 5 
Ballybunian ...... Nov. 8. —_ 1 
Valencia..........4+ — 12 — 1 
Dingle ........60 fo 18. — 1 
Kiltanon ......... Dec. 10. — 1 
Limerick ......... Dec. Jan. 1836.) S.2| 3 
Youghal............ Dec. 29. _ 2 
London .......60 April, 1836.) L.3 3 

L.4 3 

0 OT) th ae April, May. L.3 4 

April, May. L.4 4 

Limerick ......... July 15, 16. S. 2 3 

J Daplin ...........: — 22, 23. — 3 
P| Dublin ............ Oct. 4. Srey 
7% Bangor .......... Sept. 21. — 1 
London ............ Junel837,Oct.1838} S. 2 13 
Dublin’ .......0.... July, Aug. 1838. — 5 


Intensity. 


18] 


Intensity. 
* | (London=1.) 


— |__| 


1:0000 1:0250 
1-0083 1:0335 
1:0043 10294 
1:0091 10343 
1:0031 1-0282 
1:0900 1:0250 
9970 1:0219 
1-0000 
1-0000 
1:0194 
1:0189 
1:0062 
1:0000 
1:0000 1:0197 
1:0059 1:0257 
10000 
1:0185 


_ The foliowing Table contains the resulting values of the in- - 
_ tensity at each station, with the latitudes and longitudes of the 


stations. 
Taste LXXVI. 
Station, Lat. | Long. |Intensity. Station. Lat. | Long. |Intensity. 
° ou pakere 7 (ey) 

Dublin......... 53 21! 6 16 | 1:0197 |/Ennis ......... 52 51} 8 58) 1-0253 
Limerick...... 52 40} 8 35 | 1-0250 ||Cork........... 51 54] 8 26) 1-0189 
Carlingford...|54 2) 6 11 | 1:0366 ||Waterford ...)52 16] 7 8 | 1-0162 
Armagh ...... 54 21| 6 39 | 1:0242 ||Broadway ...|52 13] 6 24/1-0173 
Colerain ...... 55 8| 6 40 | 1-:0194 ||Gorey ......... 52 40} 6 17/|1-0129 
Carn. ........../55 15| 7 15 | 1:0351 ||Rathdrum ...|52 55} 6 14|1-0140 
Strabane ...... 54 49| 7 28 | 1:0299 ||Ballybunian..! 52 30] 9 41 | 1-0335 
Markree ...... 54 12] § 26 | 1-0290 || Valentia ...... 51 56} 10 17 | 1:6294 
Ballina......... 54 7/9 7 |1:0276 |\Dingle.....:...,52 8)10 17|1:0343 
Belmullet.....)54 13] °9 57 | 1:0292 |/Kiltanon...... 152 52) 8 43) 1-0282 
Achill ..... .--|53 56| 9 52 | 1-0295 || Youghal ...... '51 57) 7 50) 1-0219 
|Galway........ | 53 17| 9 4 | 1:0285 ||Bangor........[54 39] 5 42 | 1-0257 


_ Of the foregoing results, those obtained at Carlingford and 
Colerain are not included in the deduction of the isodynamic 
lines, on the grounds already stated. To all the others equal 


weights have been assigned ; the local error bearin 


VOL, VII, 


1838, N 


g so large a 


182 EIGHTH REPORT—1838. 


proportion to the error of observation, that the resulting pro- 
bable error is but slightly diminished by the multiplication of 
the observations. 

The following are the results of the calculation : 


L = 1:0252, M = + ‘000095, N= + -000058; 
u = — 31° 20/, r = -000111; 
the central station being the same as before. 


Captain Ross’s observations of intensity (according to the 
statical method) were made in the autumn of the year 1838, 
with two needles designated as RL 3 and RL4. They are 
contained in the following Table. 


TABLE LXXVII. 


Station, Date. Hour. | Temp. Angle. 
h m ° fo} ‘ 
London ......... July 10 1838} 5 0 | 68 — 13 33-2 
—= ID Seneet 4 0} 72 — 13 32:7 
ls ee 5 0} 72 — 13 30-7 
Mean...| 4 40 | 70°77 |—13 32:2 
Waterford ......|Oct. 4 ......... ll 0} 57 — 9 422 
See Ay Segeiaet 12 0| 57 — 9 39:0 
Mean...| 11 80 | 57:0 |— 9 406 
Cork ideccesctiee OEE MON cence 4 20 | 58 — 9 22-9 
SER BBE ARS SS 5 40 | 56 — 9 24:9 
a tieasde case 0 15 | 60 — 9 36:0 
Sy PT ee 135 /|}60. |— 9 391 
Mean...| 2 58] 585 |— 9 30:7 
~ |Valencia..... fese(Oets 12. iese. 0 30 | 53 — 8 362 
J ig ee ee 1 20 | 53 — 8 21:0 
[o=} Ahi 1 Pee ll 0O| 51 — 8 12] 
A teal ene 0 0; 51 — § 138 
3 Mean...| 0 12 | 52:0 |— 8 208 
yy |Killarney ...... Oct 19cn oe. 015 |}59 |— 8 444 
pegs I Ba 2 01 59 — 8 440 
Mean...| 1 8 | 59:0 |— 8 44-2 
Limerick......... Oct. 22 .cccs. 0 40 | 61 — 8 485 
ee 2 0} 61 — 8 514 
Mean 1 20 | 61:0 |— 8 50-0 
Mublings cs ccesse Oct. 80......... 10 10 | 52 — 9 343 
— 30......05. ll 0 | 52 — 9 33:7 
Mean 10 35 | 52:0 |— 9 34:0 
Londonderry ...!Nov. 6......... 045 | 49 |— 5 276 
hawt ee sak 2 0| 49 — 5 340 
Mean 1 22 | 49:0 |— 5 308 
London ......... Wee 4tdes 3 0 | 47 — 13 288 
= Aarteocueks 4 30 | 47 — 13 28:0 
Mean...| 3 45 | 47:0 |— 18 28-4 


i 
ears 
CF 


MAGNETIC SURVEY OF GREAT BRITAIN. 183 
Station. Date. Hour, | Temp. Angle. 
ee ° ie) a 
London ......... July 7... 5 30 | 70 — 26 38-4 
Sey | Near 0 30 | 70 —27 19 
Se ah Sk 130/70 |—27 4:8 
Mean...| 2 30 | 70:0 |— 26 55-0 
oS |Dublin........... Oct. 30......... 11 30 | 52 — 24 27:3 
| — BO... cere 0 0} 52 — 24 22:3 
(o=) Mean...| 11 45 | 52:0 |— 24 24-8 
© {Londonderry ...|/Nov. 6....4... 1] 20 | 51 — 22 47:6 
4 =o tuGee, tks 040|51 |—22 498 
7, Mean...) 0 0 | 51-0 |— 22 48:7 
Westport ......+6. Nov. 14 ...... 0 40 | 45 — 22 19:7 
ae 14 2 0| 45 — 22 20-9 
Mean...| 1 20 | 45:0 |— 22 20:3 
London ......... Dee. 5 ....aseee 3 0} 45 — 26 32:9 
ED isnedectes 3 40 | 45 — 26 30:3 
Mean 3 20 | 45°0 |— 26 31:6 


With respect to these observations, Captain Ross observes : 
The readings of R L 4 at Dublin, with the letters on the needle 
to the face of the instrument, gave 5° greater when facing the 
eust, and 5° less when facing the west, than the mean of similar 
facings with the needle reversed on its axle. I therefore thought 

_ that the axle had got some bend, and was totally ruined; and 
accordingly used RL 3 always in future. But at Londonderry 
I had some spare time, and thought I would try and find out the 
cause of this error, for I was sure it had sustained an injury. 

“ At Londonderry the mean of the readings E. and W., with 

the letters to the face of the instrument, was 22 degrees less 
than the mean of similar readings with the needle reversed on 
its axle. I therefore believe that some considerable irregularity 
of the axle, about the point where the needle (with its letters 
to face of instrument) should rest at about —7°, has occasioned 
this error; and the circumstance of the Dublin observation 
coming out right, is merely aécidental. In all other parts of the 
axle that I have tried, its readings agree very nearly with each 
other.” 
_ Under the circumstances above detailed, it seems necessary 
to reject the observations with RL 4 at Dublin and Londonderry. 
The following Table contains the computed results of the 
foregoing observations, and the latitudes and longitudes of the 
stations. In making the computation, no correction for tempe- 
rature has been applied to the results of RL3; the logarithmic 
correction of RL 4 is -000024.* 


* See pages 157 and 158, 
Na 


184 EIGHTH REPORT—1838. 


TasLeE LXXVIII. 


| 
Station. Lat, Long. Intensity. Station, | Lat. | Long. |Intensity. 
ee 4, 0, # Oo é ©. 22 " 
Waterford ...)52 16} 7 8|1:0197 Limerick -eisose 52 40| 8 35 | 1:0243 
Cork...ccccosres 51 54] 8 261-0211 | Dublin.........,53 21] 6 16 | 10186 
Valentia ...... 51 56|10 17] 1:0272 | Londonderry..|55 0} 7 20 | 1:0301 
Killarney...... 52 3) 9 31) 1-0253 | Westport eee | 53 48] 9 29 | 1:03829 


In deducing the position of the isodynamic lines from these re- 
sults, equal weights have been assigned to all, for the reason al- 
ready given. The following are the results of the conrputation: 

L = 10256, M=-+ -000091, N = + :000067; 
u = — 36° 29!, r = 000113. 


The results which have been above obtained respecting the 
position of the isodynamic lines in Ireland, are combined in the 
following Table: 


TasBLeE LXXIX. 


No. of 
Observers. Method. Stations, L. M. N. 


Lloyd, Sabine, Ross..|Hor. Vibr. ...| 20 1:0268 | -000075 | -000050 


Lloyd, Sabine......... Statical.........} 22 1:0252 | 000095 | -000058 
RLOSSinetsveensansn cease Hor. Vibr, ...| 12 1:0276 | 000086 | :000067 
INGER ee conodeoeacduee Statical......... 8 1:0256 | -000091 | -000067 


In deducing the mean values from the preceding results, 
we cannot, consistently with the character of the observations, 
assign to each a weight in proportion to the number of stations 
from which it is derived. If we compute the probable value 


of the intensity at each station, and compare it with that ob-— 


served, we shall find that the differences are in general smaller 
in Captain Ross’s observations than in those of the two earlier 
series ; so that the individual results are entitled to a greater 
weight. ‘This superiority is due, in great measure, to the cir- 


cumstance that, in the latter series, all the observations were _ 


taken by the same observer, with the same instrument, and 
about the same time. On instituting a similar comparison 
between the results of the two methods, it will be found that, 
in Captain Ross’s two series, the weight due to the results of 
the statical method is very nearly double of that in the method 
of vibration ; the probable errors being, nearly, in the ratio of 
lto “2. The same disparity between the methods is not 
found in the results of the two earlier series, a fact which 


ad 


seems to be fully accounted for by the imperfection of the 
instrument used by me in the statical observations, the effect 
of the magnetism of the limb (page 106 e¢ seq.) being in this 
case uncorrected. 

The equations of condition afford the means of deducing 
the weights of the preceding results, on the supposition that — 
there is no constant error. But as this cannot be supposed, 
we are left to a certain extent unguided. On the whole, we 
shall probably be not far from the truth in assigning equal 
weights to each of the former results, notwithstanding the 
disparity in the number of stations. The following are the 
‘mean values thus deduced : 

L= 1:0263, M = + :000087, N = + 000061. 

Accordingly, the probable value of the intensity at the central 
station (lat. = 53° 21’, long. = 8° 0’) is 
1 ; 1°0263. 

And from the mean values of M and N we obtain, for the di- 
rection of the isodynamic line passing through that station, 
u= — 35°0'; ye 
and for the rate of increase of the intensity in the direction 
perpendicular to that line, 
r = ‘000106. 
- In order to reduce the intensity results of the present survey 
to absolute measures, it is only necessary to determine the ab- 
solute intensity of the magnetic force at some one of the base 
stations, according to the method of Professor Gauss. This 
will be done, ere long, in Dublin; and it is therefore important 
that the ratio of the intensities in Dublin and London (with 
‘which latter station all the others are compared) should be ac- 
-curately known. 
_ For the determination of this ratio we have abundant mate- 
‘tials in the present memoir. The ratio of the horizontal inten- 
“sities in Dublin and London, as deduced from the first series, 
was found to be -9399; the result being equivalent to the mean 
of eleven distinct comparisons. If we combine with this the 
result obtained by Captain James Ross, namely, ‘9383, the 
_mean value of the horizontal intensity in Dublin is found to be 
ms -9398 ; 
‘the horizontal intensity in London being unity. But the dip in 
‘London corresponding to the mean epoch of these observations 
- (the Ist of January, 1837) is 69° 196; and that in Dublin is 
4 es 1-2; wherefore the total intensity in Dublin is 
ohh 1:0201, 
the total intensity in London being unity. 
; ain, we have found that the intensity in Dublin, as de- 
duced by the statical method from the observations made by 
Major Sabine and myself, is expressed by the number 1°0197, 


MAGNETIC SURVEY OF GREAT BRITAIN. 185 


186 EIGHTH REPORT—1838. 
the intensity in London being unity. The value of this ratio 
obtained by Captain Ross in 1838 is 1:0186; and the former 
result being equivalent to the mean of six distinct comparisons, 
the final mean is TO195; 

Of these results, deduced by the two methods, the difference 
is only “0006 ; and we should therefore err very little from the 
truth in taking their arithmetical mean. But the probable error 
of a single comparison in the latter method is so much less than 
in the former, that we shall certainly be nearer to the truth in 
adopting the latter result. We shall accordingly consider the 
number 1°0195 as expressing the ratio of the intensities of the 
magnetic force in Dublin and London. 


Report resumed hy Major Sabine. 


Collecting in one view the values of w and r resulting from 
the several series of intensity observations, we have as follows: 


TasLe LXXX. 


No. of Mean Geog. Posit. 
Method. Observer. Stations.| at. Late rT 
(o Tee’) of fe} 4 
Statical ...| Lloyd ...... 12 |52 01} 1 50 | —54 49) -000082 
Statical ...| Phillips ...} 24 |53 49| 2 08 | —47 37/-000090 
Statical ...| Sabine...... 20 |52 36| 2 11 | —52 27)|-000079 
England.< Ross ..... 
Hor. Vibr. |< Sabine... 27 +|52 48) 2 18 | —47 14] -000094 
Lloyd ... 
L es ee ener ie. Fe Ll 
Mean 74 +|52 48| 2 07 | —50 48] -000086 
Statical ...| Sabine...... 19 |56 22} 4 Ol | —52 15} -000136 
Statical ...| Ross........ 9 |56 52| 2 45 | —40 38) -000106 
Scotland.< |Hor. Vibr.| Sabine...... 21 |56 30| 4 10 | —55 46| 000143 
Hor. Vibr.| Ross........ 12 |56 56| 2 58 | —43 32) -000125 
Mean 61 | 56 40} 3 30 | —50 02) -000132 
t = Lloyd x 
| Statical ... Sabine 22 |538 21| 8 00 | —31 20) -000111 
Statical ...| Ross........ Br citecccall teens —36 29) -000113 
Ireland..{ Lloyd 
Hor. Vibr. |< Sabine Boy |crcececks|wectees —33 48 | 000090 
Ross...... 
(Hor. Vibr. | Ross......... al BAe eed Meeree re —38 00) -000109 
Mean 62 |53 21] 8 00 | —34 06 | -000104 


The values of win England and Scotland, or the angle which 
the isodynamic lines in those countries make with the meridian, 
appear to be very nearly the same; the difference in the mean 
values is much within the order of the differences of the partial 


MAGNETIC SURVEY OF GREAT BRITAIN. 187 


results. But the values of 7, or the rate of increase of the in- 
tensity corresponding to equal geographical spaces, differ con- 


- siderably, and give a decided indication that the spaces between 


the isodynamic lines are less in Scotland than in England. If 
we examine the partial results obtained in the two countries by 
the different observers, and by the different methods of obser- 
yation, we perceive that all the series are consistent in this in- 
dication. The lines which are selected for representation in the 
map are those of unity (passing through London), of 101, 1-02, 
and 1-03; the mean distance between the lines, which thus differ 
*01 in the values of the intensity they represent, is in England 
116, and in Scotland 75 geographical miles; the partial results 
vary in England from 106 to 126 miles, and in Scotland from 


69 to 94 miles. 


Whatever may be the cause of this difference in the value of 
r in the northern and southern portions of the island, it is obvi- 
ously much too great to be taken as a regular part of a general 
progression; as in its extension towards the N.W. and S.E., the 
separation between the lines would in the one case be soon ren- 
dered. extravagantly small, and in the other extravagantly great. 
. In order to deduce the position of the several isodynamic 
lines in best conformity with the observations, it is particularly 
necessary, under such circumstances, to derive each line from 
those observations only which are in its immediate vicinity ; 
and thus to reduce within very small limits the effect on each 
of the rapidly-changing and somewhat uncertain values of r. 
We require, for this purpose, only its approximate values 
in the vicinities of the respective lines ; and without entering 
into nice calculations where we have not a sufficiently satisfac- 
tory basis, we may provisionally assume these values as follows ; 
always remembering, that any inaccuracy in the assumption will 
produce an opposite effect on the deductions from the observa~ 
tions which are on either side of each isodynamic line, and that 
‘such opposite effects will counterbalance each other in the mean 
position assigned to the line. 


Approximate values of r in England and Scotland, in the vici~ 
: nity of the several isodynamic lines: 


. fine of 1-0f er. -00G08 
| | A Et 7 = 200009 
| 1-02; r = 00011 


~. +. 1:03; 7 = 000135 
_. The mean value of r in Ireland, derived from the several 
‘Series in that country, is 000104 or 000106, (page 185,) which 
corresponds so nearly with the value which might be interpo- 
lated from the results in England and Scotland for the latitude of 
the central geographical position in Ireland, that we may safely 
take -00010 as a general value for the Irish deductions. 


188 EIGHTH REPORT—1838., 


If we compare the mean value of u derived from the Irish 
series, — 34° 6’ (varying in the several partial results from 
— 31° 20’ to —38° 00'), with its mean values in England and 
Scotland — 50°, (the partial results varying from — 40° 38’ to 
— 55° 46'), we find, notwithstanding the amount of the partial 
differences, a general and consistent indication that the isody- 
namic lines are less inclined to the meridian in Ireland than in 
Great Britain. The two Irish series which give the least values 
for this angle, are those which were the earliest obtained,— 
which had consequently the disadvantages of less experience in 
the observers, and less perfection in the instruments; and of 
combining in one series observations at. different epochs, and 
results by different observers, and with different instruments. 
The two series of Captain Ross were, on the other hand, ob- 
tained by one observer with the same instruments; were well 
distributed over the country; and were made in immediate 
and rapid succession. We may therefore safely infer, as Mr. 
Lloyd has done (pages 184, 185), that the values of w derived 
from Captain Ross’s series are entitled to weight beyond the 
proportion which the number of the stations which they repre- 
sent bears to the number of stations in the other Irish series. 
Still the difference in the angle with the meridian in Ireland and 
in Great Britain cannot, in any consistency with the observa- 
tions, be less than several degrees. I have employed — 35°, 
the value deduced by Mr. Lloyd, pages 184 and 185, as the 
general mean value of win the Irish deductions. 

If we compare generally the mean results of the horizontal 
with those of the statical series, we are not able to discover any 
apparent systematic differences whatever in regard to the values 
of wand r. The individual observations by the horizontal me- 
thod do indeed exhibit much greater discordances with each 
other than is the case in the statical method. This has been 
already shown in detail in the analysis of the observations by 
the two methods in Scotland, in pages 20, 21, of the Sixth 
Report of the British Association: and Mr. Lloyd has else- 
where pointed out the causes of the advantage in this re- 
spect of the method for which we are indebted to him. Al- 
though, therefore, the accordance of the two methods, when 
the observations are grouped, is a satisfactory confirmation of 
the conclusions which they unite in establishing, the horizontal 
observations are less fitted than the statical to be employed in 
a graphical representation of the particular nature adopted in 
this report, in which the discordances of individual observa- 
tions are brought strongly into notice, and if exceeding a cer- 
tain limit might produce inconvenience, by in some degree 
perplexing the judgment. In extreme cases they might entirely 
mislead it ; as, for example, if the point furnished by an obser- 
vation for a particular line should fall nearer to an adjacent 


MAGNETIC SURVEY OF GREAT BRITAIN. 189 


line than to the one to which it really belongs; and this will 
occur whenever, from accidental causes of any kind, the dis- 
cordance exceeds in amount half the interval between the lines 
which are represented. Such extreme cases are frequent in the 
horizontal observations ; but are of very rare occurrence in the 
statical. Of the 114 statical results, there are only five which 
have been omitted in the graphical representation; (though of 
course included in the table). Four of these are, Ballybunian, 
Dingle, Gorey, and Rathdrum, all in the south of Ireland, and 
amongst our earliest observations. The two first named were 
my stations, and the intensity is in excess ;—the two others 
were Mr. Lloyd’s stations, and the intensity is in defect of the 
general body of the results; the omission of the four should 
consequently have no effect on the position of the lines. 

The fifth observation omitted in the map is Captain Ross’s 
at Berwick, which would furnish a point for the line of 1-03 ina 
geographical position which is nearer the line of 1:02. 

The evidence supplied by the collective horizontal observa- 
tions is, however, too valuable to be dispensed with in the 
Tepresentation. I have collected in the following Table the 
values of the intensity derived, for the respective mean geogra- 
_ phical positions, from the combined observations of each series, 
both horizontal and statical. In the map the central stations 
are designated thus, +, with the initial of the observer an- 
nexed; and the points furnished by the respective intensities 
for the nearest adjacent line thus, >, with H or S', according 
as the series was horizontal or statical, and a figure is added 
expressing the number of stations contributing to the result. 
In Ireland the one central station has been taken by Mr. 
Lloyd as common. to all the series, and the initials of the ob- 
server, therefore, are transferred to the points. 


Taste LXXXI. 


Statical. Horizontal. 
g Mean Geogra- 3 Mean Geogra- 
5 phical Position. Intensity.||_ 5 phical Position. Intensity. 
) Lat. | Long. 3 Lat. Long. 
ae 68 srr ee te 
P 53 49] 2 08 | 10136 |/R 7} 
MS 52 36) 2 11 | 1:0075 |S +| 52 43) 218] 1:0087 
L 52 01| 1 50 | 1:0048 LJ 
Ss 56 22| 4 01 | 1-:0290 ||s 56 30| 4 10] 1-0285 
R |56 52) 2 45 | 10277 |ir 56 56| 2 58 | 1:0302 
L 2 “NOx L 
s \ Fee |S 00.) Vee ils \ 53 21| 8 00 | 1-0268 
R |53 21| § 00 | 1:0256 RJ 
: R 53 21! 8 00 | 1:0276 


190 EIGHTH REPORT—1838. 


The General Table of the intensity results by the statical 
method is analogous to the General Table of the Dip observa- 
tions : it appears, therefore, to require no separate explanation. — 
The intensities which exceed 1-035 belong to the line of 1-04, 
of which no representation has been attempted, because the 
results on which it would rest are all, with a single exception, 
on one side of the line. The stations to which these results 
belong are, however, retained in the map, and are accom- 
panied in each case by the numerical value of the observed 
intensity. 

GENERAL TABLE. 


Intensity. Staticat Meruop. 


OBSERVATIONS. "DEDUCTIONS. 


} 
g nes el | 
| sod Lin 
Station. Lat. Long. E Intensity. id § ; of 1-03 in . 33 
2 sso rt 
6 | q 4 Lat. Long. | $= 
Lerwick .c.eosss0-0- 60 69; 167! R~ | 1-0358 , 
Kirkwall ........... 59 00) 258} R_ | 1-0373 | ’ 
Gordon Castle ....57 37} 3 09) S 1:0380 | These stations belong 
Golspie 57 58| 357| S$ 1-0360 | to the isodynamic line of 
eS ito S |1.03827 | ¢ 104, which is not drawn 
Inverness ......++. 57 28) 4 ll {k 10378 [ in the map. 
Loch Slapin ...... 57 14| 6 02} S_ | 1-0427 
Carn <)..socctiae: 55 15| 715| L |1-0351 | 
Berwick............ 55 45/200! R_ |1-0254 |425|439 56 10) 2 39 
Aberdeen ......... 57 09} 205 | R_ |1-0268 ||+18/428/57 27/ 2 33 | Jas 
Alford ...csecsseeeee 57 13|245| S |10294 |+ 4/4 5/57 17/2 50 = 
Newport ....c.c000. (56 25/255 | S |10277 |+13/420/56 38| 3 15 || $ 
Kirkaldy ........0.. 156 07/3 09| S |1-0279 |4+11/+17/56 18) 3 26 ||¢ 
Blairgowrie........ 56 36/3 18| S /|1-:0310 |— 6\— 9\56 30} 3 09 || Il 
Braemar ....se00+. 57 01/325] S  |1-0269 |+17\+26/57 18) 3.51} } &} 
Dunkeld ........... 56 35/333 | R | 10267 | +19|+28/56 54) 4 01 | | 
Helensburgh...... 5600441} S /1-0258 |+23/436/56 23/5 17 /|3 
Cumbray......s.0+ 55 48/452) S |1-:0287 |+ 8/412)55 56/5 04 || | 
Glencoe.........+++ 56 39/5 07) S |1-:0324 |—13/—-20/56 26) 4 47 || , | 
Loch Ranza ...... 55 42/517) S_ |1-0261 |+22/+33/56 04| 5 50 || 5} 
Campbellton ...... 55 23|5 38] S |1-0296 ||+ 2/4 3/55 25/5 41 . 
Bangorscccesssecess 5440 5 40) S | 10257 ||4+25/457/55 05/6 37 |) | 
Londonderry... 54 59/719] R |1-0301 ||— 1/— 1/54 58| 7 18 
Strabane 728; L |1:0299 |+ 1/4 1/54 50) 7 29 = 
Markree..... 8 26/ L |1:0290 |+ 6413/54 18} 8 39/1 
Kiltanon 843| S_ |1-0282 ||+10\4+23/53 02] 9 06 || S} 
Binns. 22b.d0e.. 2 857 | L |1-0253 ||+28/4+64/53 19/10 01 | | S| 
Galway ...... 00+. 904} L /|1-0285 ||+ 91420/53 26| 9 24 |] Il} 
Ballina ............ 907| L |1-0276 |+13/432/54 20| 9 39 | | =| 
Westport.......000. 53 48, 929| R /|1:0329 ||—17|—39|53 31| 8 50 | fo*| 
’ Killarney ......... 52 02/930) R_ | 10253 ||4+28)464/52 30/10 34 | 13 
Ballybunian ...... 52 30/941] S |1:0335 |—21\—48/52 09| 8 53 || | 
Belmullet ......... 5413/9 57| L |1-0292 | +4 5\411/54 18/10 08 | | | 
Avhill...cc2teee 53 56/952} L |1-0295 |+ 3/4 7/53 59/959}! . 
H | 1-99 | | 
aleacis ft aie 51 56 1017 {R pets + 9|+22 52 05(10 39 
Dingle: «.txscsue 520810 17| S_ | 1-0343 —25|—58 51 43/ 9 19 


MAGNETIC SURVEY OF GREAT BRITAIN. 191 


GENERAL TaBLE—(continued). 


OBSERVATIONS. DEDUCTIONS. 
5 & | Isodynamic line | ‘6 ¢ 
iS i 3 5 of 1:02 in sy 
Station. Lat. | Long. o Intensity. 4 Pe 1 |S Ne a | b= = 
6 4 a Lat. | Long. se 
Thirsk ...........(5414| 2 2t | P |1-0155 |431)445/5% 451 3 06 
P |1-0173 
Newcastle . ....... 4 58/137 | R |1-0165 } [4-261 +38) 55 24] 2 15 
! 10147 
Alnwick Castle...|55 25| 142] S |1-0159° |428|4.41/55 53| 2 93 
[Dryburgh ......... 55 34/239] Ss |1-0199 |4 1/4 1/55 35| 2 40 
“Melrose ............ 55 35) 244) S_ |1-0208 ||— 6/— 8/55 29| 2 36 || > 
Stonehouse ...... 54.55) 2 44 |{ 5 } 10176 +17}425) 55 12) 3.09 || 5 
Penrith ............ 54 40/245 | P |1-0184° |411\416]54 51/3 01 || 
Carlisle «.........../54 54/254] P |1-0198 |4 1/4 2154 551256 \1 1 
Bowness............ 54.22/255| P |1-0182 |413\418|54 35/3 13 |b * 
Patterdale ......... 54 32/256] P |10181 4124/4 19154 4613 15 | [<7 
Coniston ......... 54 22/305] P |1:0196 |l4+ 3/4 4/54 25|309/|S 
Edinburgh........./55 57/311 | S /1-0231 |~299|31/55 35/2 40 || 4 
Whitehaven ...... 54 33| 3 33 S |1:0176 ||4-16/4+-24)54 49| 3 57 I 
Glasgow ..........|55 51] 414| S | 1-0232 ||23|—32/55 98| 3 42 || | 
Jordan Hill ......|55 54) 4 21 {8 Loses } —34|_48/55 20] 3 33 
Douglas............ 5410| 4 27| P |1-0208° |_ 6|— 8\54 04| 4 19 
Castleton... 5404/4 40] P |1-0203 |— 2\— 3/54 02| 4 37 
Peelton ............/54 13/443] P |10192 |+ 6/4 8154 19] 4 51 
Loch Ryan ...... 5455/4 58| S_|1-0221 |-15|—21)54 40] 4 37 
Doblin ............|53 21| 6 16 12] 10195 + 3i4 7/53 24/6 23 |) 5 
eat 2 
Broadway ......... 52 13) 6 24) L |1-0173 | +15|436|52 28] 7 00 || 
Armagh.......... .|54 21/639) L | 10242 | 24) 57\53 55| 5 42 || >. 
| Waterford ........./52 16| 7 08 1% io197 f+ 12}+-26|52 28] 7 34 | |» 
| Youghal ...,...... 51 57| 7 50 4 10219 |—11)—-25/51 46] 7 25 || % 
1-0189 
ees 51 54) 8 26 4 ee tl o| 0 [51 54] 8 26 
es S |1-0250 
| Bimerick ........52 40) 8 36 {R vous ¢||—27|—63| 52 3 733 3 
e 


= 
w 


EIGHTH REPORT— 1838. 


GENERAL TABLE—(continued). 


OBSERVATIONS. DEDUCTIONS. 
5 a Fa Tsodynamic line| SX 
Station. Lat. | Long. E Intensity. 4H | 8 RSS EE 
ro} J} 4] wat. | Long, | 3? 
ie} 4 ° ‘ ‘ ‘ ie} ca Oo 74 
Flamborough...... 54 08} 0 08 P |1:0083 |/4+14)/4+-19) 54 22) U 27 
Scarborough ...... 54 17|024| P /|1:0103° ||\— 3/— 4/54 14] 0 20 
Whitby ......-.-06- 54 29| 0 37 P |1:0185 ||—29|—43/54 00|—0 04 
Work 1), casscsaccse's 53 58| 1 05 P |1:0126 || —22/—31/53 36) 0 34 
Doncaster .......+. 53 31} 1 07 P |1:0096 ||+ 3/+ 5/53 34| 0 12 
Hambleton ....... 54 20| 1 15 P /1:0134 ||—28)/—41/53 52| 0 34/| .. 
Osmotherley ......|54 22} 1 18 P /1:0128 ||—24|-34/53 58| 0 44/18 
Sheffield .......... 53 22} 1 31 P |1-:0124 ||—20/—28/53 02] 1 03)/|S 
Birmingham .. ... 52 28/153] P |1-:0105 ||— 4|— 6/52 24) 1 47//S 
Sbrewsbury ...... 52 43| 2 45 {§ 1.0087 } | +27 +38) 53 10) 3 23) | I 
Calderstone ...... 53 23) 2 53 P |1:0106 ||— 5|— 7/53 18} 2 46 = 
Birkenhead ....... 53 24/ 3.00 /{ | 1/9145 |-24—33)53 00] 2 27) | 
Coe a P |1-0110° ||— 8|-12/53 03] 3 00| | | 
Brecon S |1:0060 ||4+-35)4-46|52 32] 4 07) | Il 
Merthyr S |1:0081 |/-+17|4+23|52 00| 3 44|} > 
Dunraven Castle .|51 28| 3 37 S |1:0078 ||4+20|426)51 48| 4 03 
Aberysthwith...... 52 24) 4 05 S | 1:0100 0} 0 |52 24] 4 05 
Holyhead .........,53 19| 4 37 L |1:0144 ||—38)—53/52 41] 3 44 
Rathdrum ......... 52 55) 6 12 L |1:0140 ||—34|—48)52 21} 5 24 
Gorey .......e0eas- 52 41/ 6 15 L |1:0129 ||—25/—34|52 16] 5 41 


5 o te | Isodynamic line Sve 
Station, Lat. | Long. 5 Intensity. || 4 Ac} of 1:00 in oy 
tar iach: 
3 % 4 Lat. | Long. Ss 
1 
ta 4 | é/ a é 
Margate...cessese+s 51 23/1 33} s |0-9970 ||4+29+39\51 52|—0 44 
Daveshit.wis..5: 51 08|-119| S$ |0-9945 ||+53 +70 52 01|—-0 09 
Paes a: 52 47|—0 25, L |1-0030 ||—29'—39|52 18|—1 04 . 
Eastbourne ...... 50 47\-0 16 F |09937 ||451'+68 51 38| 0 52 
Cambridge........ 52 13|-0 07, L |1-0001 |— 1/— 1/52 12/0 08) | =| 
Brighton «.....+.. 50 50| 008; L |09955 ||444458/51 34] 1 06 
Worcester Park...|51 23} 017; S |1-0006 ||— 6\— 7/51 17| 0 10] Sf 
Eastwick Park .../51 17; 019} F |0-9993 ||+ 74 851 24| 0 27|| >| 
Tortington ....... 50 50| 034, S |0-9990 ||410+413/51 00] 0 47|| 1] 
St. Clair’s ws... 50 44 108| P |1-0002 ||— 2— 2/50 42] 106 $ «| 
(TER ieee Riles 50 44| 110| L |0-9972 ||427\4395/51 11| 1 45] | 3") 
Salisbury .......++ 51 04] 147| L |1:0006 ||— 6— 7\50 58| 1 40)| 3] 
Combe House ....51 31| 234, F |1-0026 ||—26 34/51 05| 2 00/| 1] 
Clifton. ....sssese0e 51 27| 236 L |1-0030 ||—29|-39/50 58] 1 57|| 
Chepstow ......++. 51 38| 2 41/ L |1-0041 ||—40—53/50 58| 1 48|| 3} 
Hereford sss... 52 04| 244) L |1-0046 |/—44'-59/51 20] 1 45 
Lew Trenchard.../50 40| 410 S |1-0045 ||—43|\-56|49 57| 3 14 
Falmouth .......+. 50.09) 5 06 { opts ¢ | —27|—22/49 52] 4 44 


MAGNETIC SURVEY OF GREAT BRITAIN. 193 


Extension of the Isoclinal and Isodynamic Lines into Meri- 
hie East and West of the British Islands. 


_ Having thus completed the representation of the principal 

ines of dip and intensity passing across the British Islands, it 
appears desirable to trace their prolongation on either side, 
until they are brought in connexion with the lines of the same 
yalue in adjacent meridians to the east and west, as determined 
‘by recent and satisfactory observations. As a single line of 
each of the phenomena will suffice to exhibit this connexion, I 
have selected for that purpose the isoclinal line of 70°, and the 
isodynamic line of 1:03. oan 

In Plate III. the portion of the isoclinal line, which is repre- 
sented by ar unbroken line, has been determined by the ob- 
‘servations contained in this report. In its eastern prolongation 
it passes through countries where its position is well assured 
by observations of higher amount on the one side, and of lower 
amount on the other, too numerous for insertion in a map on 
‘so small a scale, and too well known to need a recapitulation 
here. Towards the north-eastern extremity of the map, the 
Position of Gros Novgorod is marked in lat. 58° 31’ and long. 
31° 19', where M. Erman observed the dip 70° 261 on the 
‘15th of July, 1828, This observation, reduced to January 
1837, by allowing an annual diminution of 3’, becomes 70° 00'6: 
the line of 70° is therefore made to pass through this station. 
To the west of the British Islands, the line is prolonged until 
it is brought in connexion with M. Erman’s observations on 
his homeward passage, in August 1830. For this purpose I 
have formed M. Erman’s observations into two groups, each 
f three stations, as follows: 


1830. Lat. Long. Dip. 


° 


° ! oO 1 
Aug.19 | 41 27 | 327 25 | 70 036 Sey 
— 20 | 42 29 | 328 34| 69 47-64 70 19-4 
— 21 | 44 22 | 330 55 | 71 07:13 
— 22 | 46 46 | 335 42 | 70 18:5 
— 24 | 47 47 | 343 58 | 69 160 70 06:3 
— 25 | 47 46 | 344 25 | 70 14-9 


or eS aay = eS ES 


‘Allowing, as in Britain, an annual decrease of 2-4, the dips in 
January 1837, corresponding to the mean positions of these 
groups, are as follows; 


194 PKIGHTH REPORT—1838. 


Lat. Long. Dip. ; 


— — 


42 46 | 39858 | 70 04 
47 26 | 341 22 | 6951 


These positions are marked in the Map, and the isoclinal line 
of 70° is prolonged to the westward in correspondence with 
the mean of M. Erman’s observations thus corrected for 
epoch. 

To connect the isodynamic line of 1:03 with intensities of 
the same value in the adjacent meridians, it is necessary to ex- 
press the value of this line in terms of the arbitrary scale em- 
ployed by Continental observers, in which the force in Lon- 
don=1°372. In this scale the line of 1:03 corresponds in value 
to (1:03 x 1:372 =) 1:413. The portion of this line which is 
represented in the Map by an unbroken line has been deter- 
mined by the observations contained in this report. Its pro- 
longation to the eastward is traced in conformity with M.  ° 
Hansteen’s observations in Norway, and with MM. Han- 
steen’s and Erman’s in Russia. The station marked in lat. 
60° 11’ and long. 10° 20! is the mean geographical position of 
a group of six stations in Norway, not far removed from each 
other, for which M. Hansteen’s observations in 1821, 1823, 
and 1825, gave a mean intensity of 1°414 (7th Report, British 
Association, page 49). At Gros Novgorod (lat. 58° 31’, long. : 
31° 19’) the determinations of MM. Hansteen and Erman ac- 
corded in assigning 1°412 as the value of the force (7th Report, 
British Association, page 51), and the line has been still fur- 
ther extended, in conformity with the observations of the same 
gentlemen at Moscow, in lat. 55° 46’, and long. 37° 36/, their 
mean determination being 1°405. The position of the line in 
its western prolongation has been drawn in conformity with the 
values of the intensity at the islands of Terceira and Madeira, 
contained in the general table of the memoir on the magnetic 
intensity already referred to, viz. 


Terceira .« Fitz Roy). . -1886 3) 2) .°°1-457 


: Sabine 5). “TS22) 4. wt scl ee 
ee Kagel ce) Saeed cy xy 1igey PESTS. 
Both stations are included in the Map. ‘The values of the 
force at M. Erman’s dip stations in the same quarter, deter- 
mined by the same excellent observer, are also inserted in the 
map, as affording corroborative evidence of the correct position 
of the isodynamic line in this its western extension. 


7 
a ‘ 
—_ 

bs 


In order to render the view in this Map of the magnetic 
phenomena in the British Islands more complete, I have added 
the direction, shown by arrows, of the horizontal or compass 
needle at three extreme stations, determined by Captain James 
Clark Ross, viz. Lerwick, in the Shetland Islands; Valencia, 
at the S.W. extremity of Ireland; and Bushey, near London. 
The geographical positions of these stations, and the variations 
observed at them, are as follows, the latter being the mean va- 
riation at the epoch named, obtained by observations repeated 
every fifteen minutes from 7 a.m. to 7 p.m. for several succes- 
sive days. 


MAGNETIC SURVEY OF GREAT BRITAIN. 195 


Station. Date. Lat. Long. Variation. 
Lerwick. | July 26,1838 | 60 09 | 1 07 W.| 27 08 35 W. 
Valencia. | Oct.13, — 51 56 | 10 17 W.| 28 41 52 W. 
Bushey . | April 3, — 51 38 | 0 22 W.| 23 59 24 W. 


196 


REPORT ON THE MAGNETIC ISOCLINAL AND ISODY- 
NAMIC LINES IN THE BRITISH ISLANDS. - 


TABLE OF CONTENTS. 
Tritroduction P23. 4 oes eat VE A oe RR page 49 


Division I. Die. 


Errors of dipping needles, and recent improvements .......... 51 


Annual alteration of the Dip............ nif a o(a eds: A SE 62 
Dip ta Londons Way UGBB ops foie 04.0 «aod «is Betla een ee eee 64 
Sect. 1. Observations mHngland .. 2.0... 0. . gene ss emis de ho chee 
Sect..2.. Observations)inSeotland, 00:2)... «ao. swage ae ae 86 
Sect. 3. Observations in Ireland. (This section is by Mr. Lloyd.) 91 
Summary, and deduction of the Isoclinal lines...........- Mase oe ei 
General table of the Dip observations .......... Jamis olathe rile 125 


Drivisron II. Intensity. 


Sect. 1. Observations in f § 1. Statical method .............. 138 
England.... (§ 2. Method of horizontal vibrations .. 148 — 
Sect. 2. Observations in ¢§ 1. Statical method .............. 155 
Scotland .. | § 2. Method of horizontal vibrations.. 161 
Sect. 3. Observations in f § 1. Method of horizontal vibrations.. 165 
Ireland .... )}§ 2. Statical method. «0.01... 0.0%. 176 


(Section 3 is by Mr. Lloyd.) 


Summary, and deduction of the Isodynamic lines........ pada ania 186 
General table of the Intensity observations, by the statical method 190 


ConcLusiIon. 


Extension of the Isoclinal and Isodynamic lines into meridians east 
and west of the British Islands ............ seen es Cowan 193 


™* 


RAILWAY CONSTANTS. 197 


First Report on the Determination of the Mean Numerical 
Values of Railway Constants, By Dionysius LarpnNeEr, 
LL.D. F.R.S., &e. 


Ir will be in the recollection of the Members of the Mechani- 
cal Section of the British Association, that the circumstance out 
of which this inquiry arose, was the discordance of opinion 
which prevailed among the members of the Section, including 
several engineers and other practical men, on the subject of the 
amount of the resistance to the tractive power offered by trains 
on railways ; this resistance being variously estimated at six, 
seven, eight, nine, and even ten or twelve pounds per ton of the 
gross load. 

_ The resistance to the motion of a train of wagons or coaches 


on a level and straight line of rails arises from the following 


causes : 
1°. The friction of the axles with their bearings. 
2°, The resistance to the rolling motion of the tires on the rails. 
3°. The friction of the flanges with the rails brought into oc- 


casional contact with the latter by the lateral oscillation of the 


carriages. 
4°, The resistance of the air. 
If the line of rails be curved, another source of resistance arises 


_ from the pressure and consequent friction of the flanges of the 
outer wheels on the rails, which combined with the effects of 


the conical form of the tires, is in fact the force by which the 


direction of the motion of the train is continually changed. 


If the line be inclined at any given angle to the horizon, the 


' fesistance will be modified by the gravitation of the load ina 
_ manner which is easily inferred from the elementary principles 


of mechanics. 


The practical importance of ascertaining the proportion in 


“which the whole resistance is distributed among these several 


sources is evident. It is only by determining this that the en- 
gineer can be guided in the selection of means for reducing 
that resistance ; and the importance of reducing it will be un- 


_ derstood, when it is considered how large an item in the expen- 


diture of railway companies is locomotive power, and that the 
amount of this power is, ceteris paribus, in the exact proportion 
of the resistance of the loads which it draws. 
The first question to which the present inquiry has been di- 
rected was, to determine what the total resistance which is pro- 
VOL, VII, 1838, — ) 


198 EIGHTH REPORT—1838. 


duced on a straight and level railway by the combination of all 
the above-mentioned causes. It is a matter of regret that the 
obstacles to experiment which are produced by the great amount 
of traffic on the principal railways are such that, notwithstanding 
the lapse of time which has taken place since the commencement 
of this inquiry, means have not been obtained for making such 
an extensive and various course of experiments as would be sufii-. 
cient to solve this question. Besides the obstacles produced by 
the traffic on the different lines of railway, difficulties also arose 
in obtaining the means of experimenting, owing in some cases 
to the inability of railway companies to spare the necessary en- 
gines, carriages, and wagons. It is nevertheless due to these 
companies to state their general willingness to facilitate the in- 
vestigation, and this acknowledgement is especially cue to the 
Boards of Directors of the Grand Junction and the Liverpool 
and Manchester Railway Companies. 

Three methods for discovering the amount of resistance op- 
posed by a train to the tractive power have been proposed : 

1°. By a dynamometer, interposed between the tractive power 
and the load, which should measure and record the force exerted 
by the tractive power in drawing the load along a level and 
straight line of railway. 

2°. By observing the motion of a load down an inclined plane 
sufficiently steep to give it accelerated motion, and comparing 
the rate of its acceleration with that which it ought to receive 
from gravity, if it were subject to no resistance. 

3°. By putting a load in motion on a straight and leyel line 
of railway, so as to impart to it a certain known velocity, and 
then permitting it to run until it is brought to rest by the re- 
sistance gradually destroying the velocity imparted to it. 

Each of these methods of experimenting was attended with 
difficulties and objections. In practice, a line of rails is never 
truly level. That which is commonly called level is a line 
which, being examined from point to point at intervals—say of 
quarter miles, is found neither to rise nor fall upon the whole. 
But the surface of the rails along the intermediate parts is sub- 
ject to considerable departures from an uniform level. How- 
ever accurately they may have been laid when the line is first 
constructed, the traffic upon them soon impairs their evenness, 
and the inequalities of level become so considerable, that it fre- 
quently happens that a wagon will not rest in certain positions 
upon them, but will roll until its wheels get at the lowest point — 
of a part of the rail which has sunk. In the use of any form 
of adynamometer this circumstance produces extreme variations 
in the index, so much so that in most of those which have been 


A) BAL en il 
ie 
- ’ 


tried, the index oscillates between zero and the extreme limit of 
its play. 

Besides this difficulty, which, from the nature of the resist- 
ance, would appear to be inseparable from every form of dyna- 
mometer, another will arise if it be admitted that the atmo- 
sphere have any considerable share in producing the resistance 
which the tractive power has to overcome. The dynamometer 
must be interposed between the engine and tender, or between 
the latter and the first coach or wagon in the train; or, to speak 
more generally, it must be immediately before the coach or 
Wagon whose resistance it is used to measure, and must be 
behind the engine, tender, or carriage which precedes that load. 
It is evident that, under such circumstances, the atmospheric 
resistance will produce only a modified and partial effect on the 
dynamometer; nor will this instrument, under. such circum- 

stances, exhibit a true estimate of the resistance arising from 
friction alone, independently of the atmosphere, since the effect 
of the atmosphere is only partially intercepted by the preceding 
_ part of the train. 

The only manner in which the dynamometer could be used 
with any prospect of obtaining a tolerably correct and satisfac- 
tory result, would be to construct it in such a manner as to re- 
gister its own indications, by describing a curve on paper with 

a pencil moved by the index of the instrument, so that the ordi- 
nate of this curve would represent the resistance, and the cor- 
responding abscissa the point of the road where that resistance 
was produced. If the instrument thus constructed were applied 
with so very slow a motion as to render the atmospheric resist- 
ance so small that it might be practically disregarded, then the 
mean value of the ordinate of the curve, or, what is the same, 
the area of the curve divided by its abscissa, would express the 
mean amount of the resistance. 

The second and third methods of experimenting are those 
which have been hitherto generally used for the practical deter- 
mination of the resistance of railway trains to the tractive power. 
The combination of both has been resorted to by M. de Pam- 
bour in the following manner :—He placed the carriages whose 
resistance was to be determined upon a steep inclined plane, 
having a line nearly level at its foot, and allowing them to move 
by gravitation from a state of rest, they attained a certain velocity 
at the foot of the plane; with this velocity the carriages moved 
along the level until they were reduced to a state of rest. It 
was then assumed that the resistance was represented by the 
ratio of the difference of absolute levels of the point from which 
they started and the point at which they stopped, to the di- 

0 2 


RAILWAY CONSTANTS. 199 


200 EIGHTH REPORT—1838. 


stance, measured along the rails, between the same points. This - 


method would be unobjectionable if the resistance was, as M. de 
Pambour and most others at that time supposed it to be, inde- 
pendent of the velocity. But we shall show presently that, so 
far from this being the case, it has a dependence on the velocity 
which renders this method of experimenting altogether falla- 
cious. : 

The following method of experimenting, with a view to the 
determination of the amount of the resistance due to friction, 
occurred to the reporter as being subject to fewer objections than 
any of the methods above mentioned. 

Let two inclined planes of different acclivities be selected. 
Let A= the gradient of the steeper plane, expressed by the sine 
of its inclination, or the numerical ratio of its height to its 
length. 

Let /'= the gradient of the other plane, similarly expressed. 
Let L=a load which an engine, with an observed pressure of 
steam in the boiler, and the regulator open to an observed 
point, is capable of moving up the steeper plane at a slow uni- 
form rate; and let L’=the load which the same engine, in pre- 
cisely the same state, is capable of moving up the other plane 
at a slow uniform rate. 

The resistance on each plane will be the sum of the gravity 
of the load down the plane and the friction. Now if F repre- 
sent the friction on the former, and F’ on the latter, the resist- 
ance on the former will be 


LA+F, 
and the resistance on the latter will be 
Lh + F. 

Since these two resistances are balanced respectively by the 
tractive power of the same engine in the same state, they must 
be equal. Hence we have 

LA+F=EHUHN+F 
RW FS=LA-LW i 
. =F LA-Uh 
UL” TAL 
But F’ —F being the difference between the friction of L! and 
L, the first member of this equality will be the ratio of the fric- 


tion to the load. If this be expressed by f, we shall therefore 
have 


. 


LA-—Lh 


fat 


.* 


RAILWAY CONSTANTS. 201 


To reduce this to experiment it is only necessary to attach to 
an engine a train of loaded wagons, and so to adjust the load 
and the engine that the latter shall be just capable of drawing 
the former up the less steep plane with a slow uniform motion. 
Let it then be taken to the steeper plane, and Jet such a number 
of wagons be detached as will enable the engine, all things being 
as before, to draw the remainder slowly and uniformly up the 
steeper plane. If then for L/ in (1) be substituted the former 
load, for L the latter, and for A and /' the gradients of the two 

_ planes, the numerical value of f will be obtained by the formula 
(1), and this will be the ratio of the friction to the load for the 
wagons or carriages, which were detached to enable the engine 
to draw the load up the steeper plane. 

It is evident that this experiment may be varied by altering 
the tractive power of the engine, which may be done within 

_ practical limits, by varying the pressure of steam in the boiler, 
and the extent to which the regulator is opened. This will 
produce a corresponding variety in the values of L and L’, and 
in this way various experiments may be made on the same pair 
of planes. 

In this mode of experimenting it is not necessary that the ac- 
tual pressure of steam on the pistons be known. All that is 
indispensable is, that on both planes the tractive power of the 

engine be the same. 

The equality of the tractive power would be more satisfac- 
torily insured if the pressure of steam in the cylinders could be 
measured and recorded, but no means have yet been contrived 
for accomplishing this in locomotive engines. The pressure of 
steam in the cylinders, however, depends on, 1°, the pressure 
of steam in the boiler; 2°, the extent of the opening of the 
regulator or steam valve; 3°, on the velocity of the piston. 
‘These will be the same, if in both cases the motion of the engine 
be slow and uniform, the regulator be equally open, and the 
‘steam-guage show the same pressure. 

_ The limits of error depend on the practicability of trimming 
the load so as to accommodate it to the same tractive power of 
the engine. If the train on the less steep plane consist of a 
great number of wagons, this may be done very nearly by 
casting off a certain number of them on the steeper plane ; but, 
if necessary, the load of the wagons remaining may be trimmed 
by the addition or subtraction of weights. 

- On the Grand Junction Railway, between Madeley and Crewe, 
there is a succession of three planes which are well adapted for 
this method of experimenting : proceeding from Crewe, the first 

_ ascends at the mean inclination of 1 in 330, the second at 1 in 
260, and the third 1 in 178. 


202 EIGHTH REPORT—1838. 


As it is necessary to observe with some precision the pressure 
of steam in the boiler, during experiments made according to 
this method, the writer of this report constructed a self regis- 
tering steam-guage for the purpose. 

A smaller cylinder in which a piston is accurately fitted, simi- 
lar to the cylinder and piston of common “ indicators,” is let 
into the boiler at a place near the position of the engineer. The 
piston-rod is carried through a tube outside the boiler, in which 
it is made to act on a spiral spring, the force of which is op- 
posed to the motion of the piston, when driven upwards by the 
pressure of the steam. The position of the piston-being deter- 
mined by this spring becomes an indication of the pressure of 
steam, and so far the instrument is a mere steam-guage. 

Attached to a part of the piston-rod is a pencil, the point of 
which is lightly pressed against the surface of a drum or cylin- 
der which stands over the boiler and near the steam-guage. 
This drum is covered with paper rolled repeatedly round it, and 
gradually discharged from it to a small roller placed beside it, and 
pressed byaspring against it. On the axis of the drum is fixed 
a worm-wheel, which is driven by an endless screw. The latter 
receives its motion from a ratchet-wheel, in which a claw or 
catch acts. This claw is alternately raised and drawn down by 
some part of the machinery which has a reciprocating motion, 
so that for each stroke of either piston the ratchet-wheel is 
pulled through a space equal to one, two, three, or more of its 
teeth, according to adjustments which are provided in the appa- 
ratus. In this manner the drum receives a slow motion of ro- 
tation, bearing a known relation to the revolution of the driving- 
wheel, and therefore to the speed of the engine. By such means 
the drum may be made to revolve once in a quarter of a mile, or 
any other given distance. 

If the pressure of steam in the boiler remain unvaried, the 
pencil will continue in the same position, and the paper moving 
under it will receive the mark of a straight and horizontal line 
at a certain height, which, by a scale previously adjusted, will 
express the pressure of steam in lbs. per square inch. If, how- 
ever, the pressure of the steam vary, the pencil will have a cor- 
responding variation of height, and a curve will be traced the 
ordinate of which will express the pressure; and since the 
absciss will represent the motion of the pistons, it will repre- 
sent according to a known scale the motion of the engine along 
the road, and therefore the absciss corresponding to any ordi- 
nate will register the exact part of the road where the pressure 
of the steam was expressed by that ordinate. 

The method of investigating the amount of resistance from _ 
friction above explained is attended with the further advan- 


_ ; 


RAILWAY CONSTANTS. 203 


tage, that the result is very slightly, perhaps insensibly, affected 
by the resistance of air. The wagons whose friction is here ob- 
served, being those thrown off in passing from the less to the 
more steep plane, are preceded by others, before which the air 
is driven. Besides, the motion being slow, the resistance of 
the air to the motion of the wheels must be quite insensible, 
and the motion on both plains being at nearly the same rate, 
the same resistance, or nearly so, from the air is encountered. 
For all these reasons the quantity F — F’ in the formula (1.) may 
be taken to represent the actual resistance from friction of the 
wagons detached. 

In the course of the limited number of experiments which 
this Committee have been enabled to make, however, they have 
not yet obtained an opportunity of instituting any by this me- 
thod, the provisions for which are not easily obtained in the 
midst of the busy traffic constantly carried on upon the railways ; 
and this difficulty has been increased by the circumstance that 
there are very few gradients on railways which fulfil the con- 
ditions here required, and these few not always accessible. 

The method of determining the resistance by observing the 

accelerated motion of carriages down inclined planes, and by ob- 
serving the gradual retardation of their motion on a line where 
the inclination is not such as to render gravity greater than the 
friction, next demands attention. 

An extensive series of experiments having been formerly 
made by M. de Pambour by this method, it will be convenient, 
in the first instance, to notice the principles adopted by him and 
the chief results at which he arrived. 

Let g=the accelerating force of gravity. 

6 =the angle which the plane makes with the horizon. 

$ = the accelerating force of the load moving down the 
plane. 

T =the time of the motion counted from the moment 
at which the load commences to move by gravity 
from a state of rest. 

V =the velocity it has acquired in the time T. 


av 
dT 

M. de Pambour then infers that if the load which descends 
the plane were free from friction, we should have 


Then we shall have $ = 


dV 
ee 38 
SR cavorinetoantaty se lve (2.) 


and that if # express the space moved over in the time T, 


gsin§= 


204: EIGHTH REPORT —1838. 


Nis ti °° VdV=gsinidz, 


which being integrated, supposing that when 2 =o, V = 9, gives 
V?=2e¢xsin$. . 
But if the load be subject, as it always is in practice, to fric- 


tion, then let the retarding force of friction be f, and the above 
equation will become 


V2 =2(gsind—f)x; 


and if the load descend a succession of planes of different gra- 
dients, passing from one to the other without any shock by 
which it will lose velocity, let 2’, x", &c. represent the spaces 
over which it moves on each plane. Its motion will be then 
represented by the equation, 


V? =2 (gsind—f)xv+2 (g sin’ —/f) «+2 (gsiné" —f") a" + &c., 
or, V2=2% {(gsind—f)7} . - - » « «6 (3) 


Such is the equation obtained by M. de Pambour for the mo- 
tion of a train down one or more inclined planes. 

But this is manifestly erroneous and does not really express 
that which it professes to express: 

1st. Because the condition (2.), from which all the others are 
deduced, would be only true on the supposition that all the par- 
ticles of the load moved in lines parallel to the inclined plane 
with a common velocity V, which in fact is not the case, since 
the wheels and axles of the wagons or carriages have a motion 
compounded of a progressive and rotatory motion ; and the mass 
of these bears a considerable proportion to the whole weight of 
the load. 

2nd. Admitting that the error just mentioned were corrected, - 
it is assumed that the excess of the gravity down the plane over 
the resistance opposed to the motion is independent of the velo- 
city. Now, if any resistance be produced by the air, that re- 
sistance will increase, according to some law, with the velocity. 
It is therefore implicitly assumed in the reasoning of M. de 
Pambour, either that the resistance of the air in his experiments, 
or any other resistance depending on the velocity, is so incon- 
siderable that it may be disregarded, or that even at the greatest 
velocity it bears so small a ratio to the friction, that it may be 
confounded with the friction, and that the result will exhibit the 
mean resistance with sufficient accuracy for practical purposes. 

Let us, in the first place, see to what extent the error arising 
from the omission of the consideration of the wheels operated 
on the result of M. de Pambour’s experiments. To accomplish 


RAILWAY CONSTANTS. 205 


this we must obtain the correct solution of the problem of a 
train of wheeled carriages moving down an inclined plane, sub- 
ject only to a resistance which is independent of the velocity, 
that being the condition on which M. de Pamboutr’s investiga- 
tion proceeds. 


Let M = the gross load in tons. 
g = the velocity produced by gravity in a fall- 
ing body in one second. 
Jf = the ratio of friction to gravity. 
*.. fg = the velocity destroyed by friction in one 
second. 
Let h = the gradient or the ratio of the height of 
the plane to its length. 
*.. gh = the velocity which would be imparted to 
a body in one second moving down the 
plane without the friction. 
*.: ¢ (h—f) = the velocity which would be imparted to 
a body descending the plane by the ex- 
cess of the gravity over friction. 
Let T = the time in seconds. 
**Mg(h—f) dT = the moving force which would be impart- 
ed to the descending load in the time 
dT. 
Let V!' = the velocity of the train when started down 
the plane in feet per second. 
V = its velocity after T seconds. 
*. dV = the velocity it acquires in dT. 


Let m = the weight of a pair of wheels and their 
axles. 
dm = a particle of this mass. 


z= the distance of that particle from the 
centre of the wheel. 
r = the semi-diameter of the wheel. 
® = its angular velocity round its centre. 
*.. 2@ = the linear velocity of dm. 
2 do = the increment of its velocity in dT. 
2do dm = the increment of its moving force in d T. 


2dadm 


= = this increment reduced to the point of 


contact of the wheel with the rail. 


2 Js 
wef Bee the increment of moving force received by 
qj the entire mass of the wheels and axle 
in the time T; and this being applied 

to each pair of wheels in the train, 


206 EIGHTH REPORT—1838. 
2 +, 
S ( i Loli hl ) = the increment of moving force received 
5 by the mass of all the wheels and axles, 
But since 7 dw = dV, if dw be eliminated we have 


~2 w2 
S ( 2 da <7) =avs(f? =). 
r , 


By the principle of D’Alembert the moving forces which act 
upon the train must be in equilibrium with the moving forces 
received by it. Therefore the forces Mg (A—f) dT must fulfil 
the conditions of equilibrium with M d V, the progressive mo- 


2 22 dm 
mentum of the whole train, and d V = the re- 
e 7 


22 


volving momentum of all the wheels and axles. 
Hence we have 


Mg (h—f) dT — {m +3 (f=*)} dV =0, 


which being integrated gives 


Mg (h —ft={M+3(f=3")} (V—V)...(4,) 


The quantity Sf 2° dm being the moment of inertia of the 


wheels round their centres is equal to mA’, where £ is the di- 
stance of the principal centre of gyration from the centre of 
gravity ; and this quantity m 4° may be determined by observing 
the vibration of the wheels on any point of suspension, and 
thence determining the corresponding centre of oscillation. 


Let d = the distance of the point of suspension from the centre 

of gravity. 
1 = the distance of the centre of oscillation from the point 

of suspension. 

Then by known principles we have 

d(l—d) =k’, 
and hence m &* may be found for each pair of wheels. 
We shall therefore consider the quantity 


22> dm 
(fF) 
as thus determined, and for brevity shall call it M’, so that the 
equation (4.) shall be reduced to the form 
Mg (h—f) T=(M+M)(V—V').. » (5) 
If S express the space over which the train moves in the time 
T, then Vd T = dS, and we obtain the relation between V and 


_ 
fs 
- « 
Gs 


S by eliminating T. Hence we have 

2Meg(h—f)dS —2(M+M’) VdV=0. 
2Mg(h—f)S=(M+M))(V?—V?) . . . . | (6.) 
2(M+ M) S=Mg (A—f)T?+2V'(M+M))T . (7.) 


It is evident that from the formule (5.), (6.), and (7.), the value 

_of f may be found if the initial velocity V’ of the train and the 

time of passing the posts by which the plane is staked out be 
observed. 

If the train be allowed to move from a state of rest by gravity 
alone, the formule will be simplified by the condition V’ = 0. 
They then become 

Mg (h-—f)T=(M+M)V.... (8) 
IMe(h—f)S=(M+M)vw... . (9.) 
2(M+M)S=Mg(A-f)T? . . . . (10.) 

In the preceding formule the load is considered as descend- 
ing the gradient. If it ascend, gravity will become a retarding 
force, and the sign of / must be changed; also the sign of d V 
will become negative. The formule (5.), (6.), and (7.), will then 
become 


Meg(f+h)T=(M+M)(W—V). woe ee (11) 
2Me(7+4)S=(M+M) (V?—Vv?% .. . . (12.) 
2(M+M')S=—Meg(ft+A) T?+2V'(M+M’)T (13.) 
If in this case the load having the initial velocity V' be allowed 

to run until it stop, we shall have V = 0 °.: (11.), and (12.) be- 


ei? Mg (f+4)T=(M+M)V'... . (14) 
2Mg(f+h)S=(M+M)vVP.. . . (18.) 


In the case of retarded motion in descending a gradient less 
steep than the angle of friction, A in these formule must be 
taken negatively. 

If, therefore, the train move down an inclined plane from a 
state of rest, we shall have (9.) 


RAILWAY CONSTANTS. 207 


M 
Vee Mam * 2g(h—f)8, 
instead of 
V=2eg(h—f)S, 
according to M.de Pambour. The value of V®, therefore, ob- 
tained by him (neglecting all resistances which depend on the 
oY) is greater than the truth in the ratio of M + M’ 
to M. 


208 EIGHTH REPORT—1838. 


If the train move successively on two planes whose gradients 
are A and A’, we shall have 


Via ap yg X 28h -S)S+(U-P)S}. (16) 


If we suppose that on the second plane f>/’ the motion 
will be retarded, and still more if 4’ be negative, or, which 
is the same, if the second plane be an ascending gradient. If 
the train in such case be allowed to move until it come to rest, 
we should have V? = 0, which would give 

(h—f)S4+(W"—-f)S=0. . «. . (IF) 

Now, it is remarkable that this conclusion will follow equally 
from the correct formule which include the effect of the wheels, 
and from the erroneous formule in which that effect is omitted. 
This takes place by a compensation of two contrary errors. So 
long as the motion of the train is accelerated, the error pro- 
duced on V? by neglecting the wheels is in excess, and while it 
is retarded, the error produced on V? is in defect; and in M. de 
Pambour’s formule this excess and defect are equal. They 
therefore neutralize each other, and the final result, so far as 
respects the effect of the wheels, is thus accidentally correct. 

From the condition (17.) we obtain 

AS+A'S! 
fie ager is aaa 


The quantities 4S and A'S! are the differences between the 
levels of the extremities of the spaces § and S', and if A! be 
taken negatively when the gradient rises, the quantity 1S + A'S! 
will be the actual difference between the level of the point from 
which the train commences its motion and that of the point 
where it stops. Thus the resistance would, according to this 
reasoning, be found by dividing the difference of levels of these 
two points by the entire space run over by the train. 

The Sutton inclined plane on the Liverpool and Manchester 
Railway, falling toward Manchester, was staked out in distances 
of 110 yards, commencing from a point 1100 yards from the 
foot of the plane. The level of the tenth stake, which marked 
the foot of the plane, is stated by M. de Pambour to be 34°61 
feet below the level of the first stake. The line extending from 
the foot of the plane towards Manchester, which continued to 
fall, but in a very slight degree, was also staked out through a 
distance of more than a mile from the foot of the plane. 

Five wagons loaded with bricks, and weighing gross 31°31 
tons, were allowed to descend by gravity from the point 1100 
yards from the fout of the plane; and they continued to move 


RAILWAY CONSTANTS. 209 


along the gradient at the foot of the plane until they had traversed 
9933 feet and had attained a level 38°55 feet below the point 
from which they started. Hence, by the formule already given, 


the ratio of the friction to the load would be 2? = , being 


993300 258 
at the rate of 8°69 lbs. per ton of the gross load. 

By throwing off a quantity of the bricks the load was then 
reduced to 25°58 tons, and the experiment was repeated in the 
same manner, when the proportion of the resistance to the load 

1 
was found to be aa OF 9°17lbs. per ton. 

Three loaded wagons and an empty one were next allowed 
to run separately down the plane, and the following were the 
results. 


Difference |Ratio of Fric-| Friction in 


Gross Load. |Distance run.| “of Level, | tion to Load. | Ibs. per Ton. 
Tons, Feet. Feet. One to 
4°65 7326 37°16 197 11°36 
5°15 6663 36°95 180 12°42 
5°20 7455 37°19 200 11°17 
1:85 6204 36°78 169 13°28 


Without pursuing the experiments of M. de Pambour further, 
it will be easily perceived that the atmosphere must have exer- 
cised upon them an influence much greater than he suspected, 
and certainly greater than he has taken any account of in the 
computations which he has founded on them. 

When the five wagons were charged with a load amounting 
to 31°31 tons gross, the resistance computed by the formula 
(18.) was 8°69 lbs. per ton, and the total resistance was conse- 
quently 272 lbs. When the gross load of the same wagons was 
reduced to 25°58 tons, the resistance per ton, computed in the 
same way, was 9°17 lbs., and the total resistance was 235 lbs. 

If the resistance were, like friction, proportional only to the 
load, the resistance per ton would have been the same in both 
cases. But we find, on the contrary, that by diminishing the 
gross load, the gross resistance is not diminished in so great a 
proportion and the resistance per ton is increased*, 


* All the experiments which have been made to develope the laws of friction, 
go to prove that, except in extreme cases, friction bears an invariable ratio to 
the pressure on the rubbing surfaces. When pressures, however, bearing a 
very high ratio to one another ave compared, the corresponding quantities of 
friction are not found to be in this ratio, the friction corresponding to the greater 
pressure bearing a ratio to that corresponding to the lesser pressure, less than 
that of the pressures. ‘This exception to the law of the constant ratio between 
the friction and pressure has, however, no application in a case like the above, 


210 EIGHTH REPORT—1838. 


This is just the effect which the resistanee of the air would 
produce. If the velocity were the same in both experiments, 
that part of the total resistance due to the air would be the same, 
because the same wagons being used in each case, the same 
surfaces were exposed to the air. In that case, therefore, the 
same amount of atmospheric resistance being divided amongst. 
a less number of tons, there would necessarily be a greater re- 
sistance per ton in the second experiment, and the gross re- 
sistance of the train would be diminished in a less proportion 
than the load. 

But it is evident that the mean velocity must have been less 
with the lesser than with the greater load, because a less amount 
of atmospheric resistance would be sufficient, combined with 
friction, to balance the diminished effect of gravitation. M. de 
Pambour, however, did not observe, or at least has not recorded, 
the time which the train took in any case to move down the 
plane, or to come to rest, and has not, therefore, supplied any 
data by which the mean speed can be computed. 

If it be admitted that the resistance due to friction is inde- 
pendent of the velocity, it will follow that the difference between 
the resistance per ton in the one experiment and the other must 
be altogether ascribed to the air. Now, if A express the whole 
resistance due to the air in the first experiment, and A’ in the 
second, we shall therefore have 


A! A 
25°58 31°31 
equal to the difference of the resistance per ton in the one case 
and the other. Hence we shall have 
clay. 
25°58 3 =31°31 
Let A’ = A— A. Hence we obtain 
1 1 A 
- loses Sega ys OOO Begs 
Whence we find 


= 9:17 — 8-69 = 0°48. 


A=67+4+5°5A. 


In the absence of the necessary data for determining A, we can 
only infer from this that A > 67. Now let /’ be the resistance 
due to friction, properly so called, in lbs. per ton. We have 
then 
31:31 f' + A = 272, 
3131 fl = 272 — A. 


ae 
ine 
ha att 
Py 
Py a9 
oof 


RAILWAY CONSTANTS, 219 


But since A > 67, 
31°31 f! < 272 — 67 = 205, 
pt i ie TF 

Thus it follows that the resistance from friction, properly so 

called, in these experiments was less than 6;5,lbs. per ton, and 

the angle of friction would therefore be less than 1 in 340. 

These results are not as definite as could be desired, but they 

seem to be the only ones to which the data supplied by the ex- 

periments are sufficient to conduct us. Had the moment of the 
train commencing to move, and the moment it came to rest, 
been observed, its mean velocity would in each case have been 
known ; and although that would not have been sufficient to 
establish the amount of resistance at any given speed, it would 
at least have supplied the means of better approximation. Had 
the experiment, however, been satisfactorily conducted with a 
view to develop the effect of the resistance of the air, the time 
of passing each successive stake should have been observed, and 
thus the rate of the variation of the speed would have been dis- 
_ coyerable, as we shall presently perceive. 

Since the preceding paragraphs were set in type, the writer of 
this report has been favoured by Mr. Edward Woods, engineer 
to the Liverpool and Manchester Railway Company, (to whose 
intelligent aid the Committee has been throughout its proceed- 
ings much indebted,) with an account of the times of passing the 
successive stakes in the experiment made with the five wagons 
loaded with the reduced weight of 25°58 tons. Mr. Woods, 
however, wishes it to be understood that for this observation of 
the times M. de Pambour is not responsible, it having been taken 
on the occasion by Mr. Woods himself for his individual satis- 
faction. 


a o 3 2 3 
is} o oS ° o =) 
5 £| 54 5 2 pee 8 
. |2| Levels, |'s| &5 | Time. | © | Levels aq $5 | Time, |2/ Levels. 
é a| &* 2 a la" 2 
Ke A | ra} be} 
A fa) A 
.|h m s| ft. in yards|h m s]| s | ft. in. yards,}h m s/{s| ft, in. 
0 5 0 04/18} 1210/7 8 2] 10] 35 03 7 2420 |7 10 38/20] 37 1°7 
110 52/52) 3 5°7/|17| 1320 13] 11] 35 23 6 2530 | 11 1/23) 37 26 
220 6 14/22) 7 0°8||16} 1430 23| 10/35 2°8 5 2640 26 |25| 37 4°5 
330 31/17} 10 7°5||15) 1540 343) 113) 35 44 4 2750 56 |30) 37 4°1 
440 46/15) 14 4°3//14) 1650 47 | 123) 35 8°5 3 2860 | 12 34/38] 37 11°1 
550 59|13) 18 2°1//13} 1760 9 0/13 | 36 271 2 2970 13 25 |51 
7 11}12) 21 9*3|/12| 1870 14 | 14] 36 5°3 1 3080 | 14 42/77| 38 4:2 
77 22/11) 25 6°4//11) 1980 28 | 14 | 36 7°9||4+28yds.| 3108 | 15 20/38 
880 32/10] 28 11°8}|10) 2090 44] 16] 36 96 
0 42/10) 32 0°8}/ 9} 2200 | 10 0 | 16 | 36 11°0 
19] 1100 52/10) 34 7°3/] 8| 2310 18 | 18] 37 07 


The foot of the inclined plane corresponded with the stake 
No. 19; and it will be observed, that the time of descending 


212 EIGHTH REPORT—1838. 


1100 yards was 172 seconds, and that therefore the mean ve- 
locity of the descent was 19°18 feet per second. But by com- 
paring the times of descending each successive interval of 110 
yards, it will be observed that the rate of acceleration, instead 
of being uniform, as it would be independently of the resistance 
of the air, is gradually less; and the last 330 yards of the plane 
was descended at an uniform velocity of 33 feet per second. 
Mr. Woods has computed the value of f, determined by the 
formula 10, page 207, for the first 110 yards, the first 220 yards, 
the first 330 yards, and the first 440 yards, and the following , 
are the results. 


1. From 0 to 110 yards f = ‘00228 = 5°107 pounds per ton. 
2. From 0 to 220 yards f = *00255 = 5:712 pounds per ton. 
3. From 0 to 330 yards f = ‘00265 = 5°936 pounds per ton. 
4. From 0 to 440 yards f = ‘00293 = 6°563 pounds per ton. 


The increasing value of f shows the increase of the resistance 
with the velocity. In the first 110 yards, the mean velocity 
being only 6°34 feet per second, the resistance of the atmosphere 
was trifling, and the value of f may be considered as a close ap- 
proximation to the friction, properly so called. 

Since in the first 110 yards there must have been some atmo- 
spheric resistance, however small, it follows that the friction, 
properly so called, must have been less than the value of f ob- 
tained by Mr. Woods’ calculation. We shall therefore assume — 
that f was in this case less than 5°11 pounds per ton. The total 
amount of friction, therefore, for the load of 25°58 tons would 
be less than 130°7 pounds. If we take the mean resistance of — 
this load at 9°17 pounds per ton, as determined by M. de Pam- 
bour’s method, we shall find the total mean resistance to be — 
234°55 pounds. The mean atmospheric resistance would there- 
fore be greater than 104 pounds. ‘ 

It will be observed that this result is in accordance with that 
already obtained for the load of 31°31 tons, by adifferent process 
of reasoning. The determination of the limit of f, by the for- 
mula (10.), may, however, be regarded as a closer approximation. 

The angle of friction corresponding to 5°11 pounds per ton, — 
would be 1 in 438. Therefore f < a 

We shall not pursue these experiments of M. de Pambour 
further than to observe, that the computed resistances of the — 
single wagons, as given in p. 209, rendered the effects of the — 
resistance of the air still more apparent. While the mean — 
computed resistance of the train of five wagons was only 8°69 
Ibs. per ton, their gross weight being 31°31 tons, that of the — 


RAILWAY CONSTANTS. 213 


single wagons was about 11°3 lbs. per ton. This difference 
M. de Pambour ascribed to the atmosphere, yet it does not ap- 
pear to have occurred to him to direct his experiments or cal- 
culations to the determination of the share which friction and 
the air had respectively in resisting the motion. Having disre- 
garded in all cases the effect of the velocity in modifying the 
resistance, and having based all his calculations on suppositions 
which are only applicable to friction, we must conclude, that 
he regarded the effects of the air as so inconsiderable, that, 
without any error of practical importance, the mean retardation 
due to them might be considered as part of the friction. 

It has been thought right to bestow some attention on the ex- 
periments and calculations of M. de Pambour in this place, be- 
cause they are not only the most extensive series of which we 
have any knowledge, but because much stress is usually laid on 
them by engineers and others who are interested in these ques- 
tions. We shall, however, presently demonstrate that the re- 
sistance of railway trains has so important a dependence on the 
velocity, that no principle of calculation can be admitted which 
proceeds, like those of M. de Pambour, upon the supposition 
of aconstant amount of resistance. But we shall also be enabled 
to give a conclusive proof, founded on direct experiments, that 
_ the method of determining the resistance by the formula (18.) 

adopted by M. de Pambour is altogether fallacious, and that by 
such a method any value, however great, of the resistance might 
have been obtained. 
__ Having noticed these erroneous conclusions to which M. de 
Pambour has arrived, it is but justice to that gentleman at the 
same time to acknowledge the activity and zeal with which he 
pursued his inquiries, and the quantity of valuable results of his 
extensive experiments by which he has enriched the practical 
science of this country. That M. de Pambour should have over- 
looked or underrated a source of resistance to locomotive power, 
which, however obvious, had eluded the attention of the whole 
engineering profession in Great Britain, as well as of his own 
country, will not, we are sure, be felt by him to be any serious 
disparagement to his sagacity. 
_ In commencing this inquiry, it was not. suspected that that 
part of the resistance which increases with the velocity, the 
chief part of which, if not the whole, is probably due to the 
atmosphere, formed so important an agent in opposition to the 
moving power on railways worked at high speeds as the results 
of experiments which were subsequently made have proved it 
to be; and in the acknowledgment of this oversight the writer 
of this report very willingly joins. This source of resistance 
VOL, VII, 1838, P 


214 EIGHTH REPORT—1838. 


had been however to an equal extent neglected, so far as we are 
informed, by engineers generally, and indeed by all who had 
directed their attention to the practical working of railways and 
to the experimental investigation of their effects. Some scien- 
tific men had called the attention of engineers to the subject, 
and Mr. Herapath more especially insisted on its importance, 
made various calculations of its probable effects, and predicted 
that on railways worked at high speeds it would prove to be the 
chief source of resistance to the moving power. As, how- 
ever, no direct experiments had been made to demonstrate its 
amount, and as it was known that the theory of the resistance 
of elastic fluids had not been based on experiments with suf- 
ficient certainty and precision to render its principles capable 
of being applied for practical purposes in operations of the kind 
now considered, these suggestions were disregarded, and the 
effects of the resistance of the air continued to be considered 
as sufficiently allowed for by estimating them in combination 
with friction at mean speeds, no attempt whatever having been 
made to ascertain experimentally the variation of resistance of 
the same loads at different speeds. 

It was determined, in the first instance, to repeat and vary 
the experiments on the accelerated motion of trains down in- 
clined planes, and their retarded motion in running to rest 
where the resistance exceeded the moving power. 

The first experiments made with this view were tried on the 
same inclined plane on which the experiments of M. de Pam- 
bour were made, viz. the Sutton plane on the Liverpool and 
Manchester Railway. This plane and the level at its foot were 
staked out as in M. de Pambour’s experiments, but in the pre- 
sent case the time of passing each successive stake was observed 
and recorded, so that the variation of speed, during the motion, 
might be rendered apparent. 

In these experiments it became manifest, that the rate of ac- 
celeration in the descent and the subsequent retardation could 
not be represented by the formule for uniformly accelerating 
and retarding forces, and that therefore some force was in ope- 
ration which, unlike friction, had a dependence on the velocity. 

To decide this, it was determined to try the effect of gravity 
on a train of loaded wagons descending an inclined plane less 
steep than those which occur upon the Liverpool and Man- 


chester Railway, and for that purpose the Madeley plane on the — 


Grand Junction Railway, already mentioned, was selected, and, 


as a first trial, a train of wagons loaded with iron rails and — 


chairs was prepared. This train was placed near the summit _ 
of the plane, and was allowed to move down by gravity. The — 


RAILWAY CONSTANTS, 215 


plane was staked out in distances of a hundred yards by 58 
stakes, commencing from the lowest point and numbered up- 
wards, and the inclination was ascertained to be at the rate of 
1 in 178, with great uniformity, throughout the whole length of 
5800 yards. 

The time of passing the stakes successively being observed, it 
was found that the motion of the wagons was accelerated rapidly 
at first, but gradually less and less, until at length all acceleration 
ceased and a perfectly uniform motion was maintained to the 
foot of the plane. 

The unfavourable state of the weather prevented the circum- 
stances of these earlier experiments from being observed and 
recorded with sufficient accuracy to render them fit to be taken 
as the basis of any exact calculation of resistance, but more 
than sufficient evidence was obtained from them that no prin- 
ciples of calculation could be applied to the motion of trains on 
railways with any view to accurate results, or even to a rough 
approximation in which the increase of resistance due to the 
increase of velocity is not allowed for. 

The problem which now presented itself for solution was the 
motion of a train of wheeled carriages subject to resistances 
which have some dependence on the velocity. All the investi- 
gations which have been hitherto made respecting friction are 
in accordance in showing that the amount of this resistance is 
independent of the velocity; and unless it be maintained that 
the friction of carriages on railways differs from all the varieties 
of friction to which experimental inquiry has been directed, it 
must be admitted that the part of the resistance to railway car- 
riages which depends on friction is independent of the velocity 
of the motion. 

_ The problem of the resistance opposed by fluids to solids 
moving through them has been investigated by Newton, and by 
the most eminent of his successors, Bernoulli, Euler, and the 
principal mathematicians of the last century. Their researches, 
however, so far as regards the resistance of elastic fluids, are 
more remarkable for profound mathematical skill than for prac- 
tical usefulness, most of them being founded on conditions in- 
applicable to the actual motion of bodies through the air, and 
leading to results more or less in discordance with experience. 
_ The earliest experiments on the resistance of the air to bodies 
moving through it which are entitled to attention, are those of 
|Robins, made about the middle of the last century. These were 
subsequently repeated and to some extent varied by Borda, 
|who published the results of his inquiry in the Memoirs of the 
Academy of Sciences of Paris, in 1763. 

P2 


216 EIGHTH REPORT—1838. 


The object of the experiments of Robins was to obtain grounds 
for a practical treatise on gunnery, and they were accordingly 
limited for the most part to the motion of cannon balls at high 
velocities. ‘The result of these experiments was to prove, that 
the law of the resistance being proportional to the square of-the 
velocity was not true in comparing slow with very high speeds. 
It. was found, for example, to give a resistance in some cases 
three times less than the actual resistance, showing, that when 
extended to such limits, the resistance must vary in a much 
higher proportion. 

Dr. Hutton was, so far as we are informed, the latest inquirer 
who undertook a course of experiments with the view of de- 
termining the amount and the law of the atmospheric resistance. 
Besides directing his inquiries to more varied velocities, he also 
endeavoured to investigate the effects which the form of the 
moving body produces upon the resistance. The experiments 
were made with hemispheres moved alternately with the con- 
vex and flat sides foremost, with cones moved alternately with 
the point and base foremost, with cylinders moved with the end 
foremost, and with spheres. 

It was found that at moderate velocities the resistance did not 
sensibly vary from the law of the squares of the velocities ; but 
in comparing slow speeds with high speeds, a gradual departure 
from that law took place, the resistance increasing in a higher 

ratio. 

In comparing together bodies exposing a frontage of different 
magnitudes with the same speed, it was found that the resist- 
ance was not proportional to the magnitude of the frontage, but 
in some higher unascertained ratio. 

It was also found that the resistance did not depend alone on 
the magnitude of the transverse section, for that with the same 
transverse section different resistances were encountered accord- 
ing to the form of the body. Thus, in general, a flat front pro- 
duced more resistance than a round or pointed one. But on the 
other hand, the resistance was not found to diminish in propor-_ 
tion to the sharpness of the foremost end of the moving body; 
but that, on the contrary, a body presenting a hemispherical 
end was less resisted than one presenting a conical end, the 
transverse section of both being the same. 

It was also found that the resistance did not depend alone on 
the magnitude or form of the foremost end, but had some de= 
pendence on the hinder part. Thus, a cone, hemisphere, and 
cylinder, having equal bases, moved base foremost, with the same 
velocity, suffered different resistances. 


No law was obtained from these experiments by which thal 


RAILWAY CONSTANTS. 217 


resistance of a body could be calculated from its form and mag- 
nitude. The results obtained were merely negative, showing 
that the resistance could zot be calculated on such or such data, 
but that it depended on some principle not yet discovered, and 
which the experiments themselves of Dr. Hutton did not de- 
velop. 

These experiments also were made on bodies of very limited 
magnitude: the bases of the cones, cylinders and hemispheres 
were less than a quarter of a square foot. It will therefore be 
apparent, that they furnish no just grounds by which the resist- 
ance to bodies of the form and magnitude of railway trains can 
be computed independently of experiment. How strongly Dr. 
Hutton himself was impressed with the imperfect nature of his 
results, and with the necessity for further experimental inquiry 
before any real or satisfactory determination of the atmospheric 
resistance could be obtained, will be collected from the fol- 
lowing observations, with which he closes this part of the in- 

uiry : 
** On a review of the whole of the premises, we find that the 
resistance of the air, as determined from the foregoing experi- 
ments, differs very widely, both in respect to its quantity on all 
figures, and in regard to the proportion of its action on oblique 
_ surfaces, from the same actions and resistances, as assigned by 
the most plausible andimposing theories which have been hitherto 
delivered and confided in by philosophers. Hence it may be con- 
cluded that all the speculative theories on the resistance of the 
air hitherto laid down are very erroneous, and that it is from 
experiments only, carefully and skilfully executed, that a rational 
hope can be grounded of deducing and establishing a true and 
useful theory of the action of forces so intimately connected with 
the numerous and important concerns of human life.”’ 
_ Since the only two sources of resistance to moving bodies 
| with which we are acquainted, are the friction of the parts mo- 
| ying upon and against one another, and the resistance of the at- 
‘mosphere through which the body moves ; and since all scientific 
experiments which have been directed to ascertain the law of 
the former agree in showing it to be proportional to the weight 
_or pressure and independent of the velocity, and that the latter, 
Within moderate limits of speed, varies in a proportion, ceteris 
paribus, not much departing from that of the square of the velo- 
city ; the form which may with most probability be assigned to 
the expression for the resistance of a railway train will be one 
consisting of two terms, one of which is proportional to the load 
and the same at all velocities, while the other for the same train 
will vary as the square of the velocity. If, then, R express the 


218 EIGHTH REPORT—1838. 


whole resistance of a train moving with a velocity V, we shall 
have 

R=aVv?+B. 
Now, since B is proportional to the load, if M express the load 
in tons, and f the resistance for a load of one ton with an inde- 
finitely slow motion, we shall have 


B=Mf, 
R=aV?+/M. 


The coefficient a being the constant number which, being 
multiplied by the square of the velocity, gives that portion of 
the resistance which varies with the velocity, will depend on 
the form and magnitude of the train, on the number, form, and 
magnitude of the wheels, and in general on any circumstances 
by which the resistance of the air to the moving parts of the 
train may be affected. But it should be observed, also, that 
there is nothing in the mere mathematical formula which limits 
the term a V* to represent the effect of the air; that term in 
fact represents any effect which would be attended with a resist- 
ance proportional to the square of the velocity. 

If any means were devised by which the total resistance of 
the same train at two different velocities could be found, the 
value of the coefficient a might then be determined; for let R 
and R’ be the two resistances of the same train at the velocities 
V and V’, then we have 


and therefore 


R=aVv?+Mf 
R' =aV?+Mf 
ap MRS ets, 
aia pias 9 


Hence it appears that the difference between the two observed 
resistances, divided by the difference of the squares of the cor- 
responding velocities, would be the value of a. 

But as the estimation of the resistance of trains by any direct 
means is attended with difficulty, it may be useful to seek in 
the circumstances of accelerated and retarded motion on inclined 
planes which are straight, other means for the solution of this 
problem. 

If R, as already explained, express the ratio of the retarding 
force produced by the whole resistance to the retarding force 
of gravity, expressed as usual by g, then the velocity which 
gravity would destroy in the time d T being g d T, the velocity 
which the resistance would detroy in the same time will be 
RgdT. 


emcee 


RAILWAY CONSTANTS. 219 


If we suppose the train to move down an inclined plane whose 
gradient is A, the effective moving force will then be the excess 
of the gravitation of the train down the plane above this resist- 
ing force: this excess will be 

Mig—Rg; 
and the moving force which that will impart in the time d T 
will be 
(MA—R) gdT. 
This, by the principle of D’Alembert, must be in equilibrium 
with the moving force which in the same time shall be received 
by the train; and since this moving force, including as before 
that which is absorbed by the revolution of the wheels, will be 
(M+ M’)dV, 
we shall have 
(MA—R)gdT=(M+M)dV; 
and substituting for R its value already found, this will become 
{M(A—f)-aV’?} gdT=(M + M)dV. 

To integrate this, let 

eee ay ay MED, ae 

oy MG—/) vay = nN a 
Hence we have 

VW Ma (h—/f) (1—2*) gdT =(M 4+ M’) dz 

_, VMa(h—f) SiS AEP, 

eae Mt gdT= 2) 
which being integrated gives 

AS Ae ee ee eee 

MM 8 aa a 
the logarithm being hyperbolic. 

If 2! be the value of x, which corresponds to T = 0, the above 
integral will become 

VY Ma(h—/f) a , (1 + 2) (1 — a’) 
-MemM 89-3" a aadey 8) 
The relation between V and S may be found by eliminating T 
by VdT = dS, by which we obtain 
{M (4 —f)-—aV?}gdS =(M+M) Vdv 
Sa VdV 
““M+M'" M(A—/f) —aV” 


220 EIGHTH REPORT—1838. 


which being integrated gives 
oO — — 12 - 
BE ug MIMD id) EN tates Ses a 
M + M’ M (h — f) — a V® 
where V! is the value of V corresponding to S = 0 and T = 0, 
and is therefore the initial velocity. 

Hitherto the train has been assumed to move with accelerated 
motion down an inclined plane. If it ascend, having received © 
any initial velocity, V', the motion will be retarded, and the 
equation will be 

{M(hA+f)+aV?} gdT= — (M+ M)dV. 
Substituting as before, let 
Cael, gee pee at ars 
a =MaEy) Ae r. dx. 
Hence we have 
V¥VMa(h+f)(1 +2) gdT=—(M+M) dex 
VY Ma(h +f) dx 
CR a ee ana 
which being integrated between the limits x and 2', the value 2! 
corresponding to 'T = 0, we have 
“V¥Ma(h+/) rh Monge 
M + M! Vl+.aea" 
And substituting for 2 and 2! their values, we find 
VM a(h +f) pa “Mah + f).(V'—V) hi 
a SoM ee ae 
The relation between V and S will be found as before: 
2a2 8%: / = (A+ f) + sa 
M+M ~ \M(A+f)+aV?/7" 
If the train move down a plane, of which the gradient is such 


that h< f, the motion will be retarded, and in that case the 
equations may be put under the forms 


tan 


tan 


(22.) 


WM a(/— fh) rie V¥Ma(f—A)(V'—V) 
an er ae TM (f 2) pa Winoll ae 
2ag8 


ip M (fh), + ie) 
M+M \M(f—A) + aV?/" 

Such are, then, the equations of the motion of a train of wheeled 
carriages which are submitted to the action of accelerating and 
retarding forces, or retarding forces only which are independent 


(24,) 


, ie 


RAILWAY CONSTANTS. 221 


of the velocity, combined with a retarding force which is propor- 
tional to the square of the velocity ; and such will be the actual 
equations of the motion of a train of railway carriages if the 
friction be independent of the speed, and the resistance of the 
air, and any other retarding forces which act upon it, be as the 
square of the speed. 

It will now be a matter for consideration, in what manner ex- 
periments may be devised so as to enable us to determine the 
values of the constants f and a. 

If a train descend an inclined plane by gravity with accelerated 
motion, that part of the resistance which increases with the 
speed will be continually augmented, while the accelerating 
force of gravity will remain unaltered. At length, therefore, a 
velocity will be attained which will render the resistance so 
great that it will be equal to the accelerating force of gravity, 
and then all acceleration will cease, and the train will move with 
an uniform velocity. The condition under which this will take 
place will be expressed by putting the value of d V = 0, which 
gives 

M(A—f) —aV?=0 
Se me Eg Tt EN, ORY 


where V is the uniform velocity attained in moving down the 
gradient h. 

If the same train be moved down another gradient, /!, another 
uniform velocity, V', will be attained, and we shall have the con- 
dition 

Mf+aV?=MHh. 

From these two equations the values of a and f may be ob- 
tained. 

M (h — A’) 
a= V2 Viz. e ° ° . . . (26.) 


V2 ih’ — VPA 
7 Re cay . ° . % ° (27.) 


If, therefore, two inclined planes be selected sufficiently steep to 
produce accelerated motion in the train, and if the same train 
be allowed to descend them until it acquire an uniform velocity, 
this will give values for V and V’; the inclinations of the planes 
will determine / and /', and the weight of the train will deter- 
mine M. The values of a and f may then be computed by the 
above formule. 

In the practical application of this method there are some cir- 
cumstances which will demand attention. It may happen that 


222 EIGHTH REPORT.—1838. 


the inclined plane selected for the experiment may not have suf- 
ficient length to allow the acceleration of the train by gravity to 
continue till the velocity become uniform. It will therefore be 
more convenient to dismiss the train with a considerable speed 
from the top of the plane, which may be done by impelling it 
by means of a locomotive engine towards the top of the plane, 
and detaching the engine so that the train shall be started down 
the plane with the velocity given to it by the engine. If this 
velocity be less than that which balances the accelerating force 
down the plane, the train will be accelerated until it attain the 
limiting speed. If it be greater, then it will be retarded by the 
air until it be reduced to the limiting speed. 

In the preceding investigation we have proceeded upon the 
supposition that the air through which the train is moved is 
quiescent. The effects of a wind of any considerable force would 
generally be so complicated, that it would be difficult indeed to 
introduce them into the calculation in such a manner as to give 
results of any practical value. If the wind blow in the direction 
of the motion, the velocity of the train through the air will be 
the difference between the velocity of the train and the velocity 
of the wind; and if this was all the effect to be considered, the 
investigation would not be attended with much difficulty ; for it 
would only be necessary to consider in that case the velocities 
expressed by V and V! in the preceding formula to_be the excess 
of the velocity of the train above that of the air. But it should 
be remembered, that besides the progressive motion of the train, 
a part of the resistance which is assumed to vary in proportion 
to the square of the velocity, is produced by the revolution of 
the wheels. Now this part of the resistance is not affected by 
the wind, and will be the same whatever be the state of the 
atmosphere. Thus it is possible to suppose the velocity of the 
train equal to the velocity of the wind, and therefore no resist- 
ance whatever to be produced by the progressive motion of the 
train. Nevertheless, in such a case, it is evident that the revo- 
lution of the wheels would produce by the action of their spokes 
the same resistance as if the atmosphere were calm. These con- 
siderations appear to lead to the conclusion, that the diminution 
of resistance to be expected from a wind blowing in favour of a 
train, and the increase of resistance from a wind blowing against 
it, will not be so great as it might be expected to be, if no effect 
but the progressive motion were taken into account. 

But if a correct investigation of the effects of a wind either 
directly favourable or directly adverse to the motion of a train 
be attended with doubt and difficulty, the effects of every side 
or oblique wind are still more so. An oblique wind would be 


RAILWAY CONSTANTS. 223 


resolved into components parallel and perpendicular to the mo- 
tion of the train. The component parallel to the motion would 
then be treated as a wind directly favourable or adverse. The 
lateral component acting against the extensive surface usually 
presented by the side of the train, would have the effect of press- 
ing the flanges of the opposite wheels against the rails. This, 
combined with the effect of the conical form of the tires, would 
have a tendency to impart to the carriages an oscillating motion 
between the rails, causing the flanges alternately to strike the 
rails, and thereby to produce a resistance the amount of which 
it would be difficult indeed to reduce to general methods of cal- 
culation. 

It appears, therefore, most desirable that experiments for the 
exact determination of the mean amount of resistance to railway 
trains should be made when the atmosphere is calm, but it is 
rarely that this condition can be obtained. In its absence, the 
results of the experiments can only be regarded as approxima- 
tions, more or less precise as the disturbing causes exist in a 
less or greater degree. 

It was not easy to find on the railways which have been com- 
pleted inclined planes in convenient situations in all respects 
suited for the plan of investigation which was contemplated. On 
the whole, however, it seemed that the most eligible were the 
Whiston and Sutton inclines on the Liverpool and Manchester 
Railway, and a series of inclines between Madeley and Crewe 
on the Grand Junction Railway. 

The summit of the Whiston plane is at about nine miles from 
Liverpool, and the plane falls at nearly an uniform rate of 1 in 
96 towards Liverpool for a distance of 2700 yards. From the 
foot of the plane the line rises at the average rate of 1 in 936 for 
a distance exceeding the range of the experiments. 

A stake marked 0 was placed at the summit.of the plane, and 
twenty-seven other stakes, marked successively 1, 2, 3, &c., di- 
vided the whole length of the plane into spaces of 100 yards. 
The distance from the 27th stake, which marked the foot of the 
plane, to the 24th mile post was 150 yards, and the line from 
that point towards Liverpool was divided by quarter-mile posts, 
the levels of which were taken. 

The inclined plane thus divided by the twenty-seven stakes 
was perfectly straight from the summit to the 24th stake. At 
that stake curves having a radius of 3300 yards commenced, 
which terminated at the 243 mile post, a point about 900 yards 
from the foot of the plane. From that point to a point 220 
yards beyond the 243 mile post from Manchester the line was 
straight, and from the latter point to 370 yards beyond the 25th 


224 EIGHTH REPORT—1838. 


mile post it was curved with a radius of 2700 yards. Beyond 
the last point the line was straight. : 

The following experiments, which were conducted by the re- 
porter, assisted by Mr. Edward Woods, were made on the south 
dine of rails of this incline. The line was laid with parallel 
rails on stone blocks. The weight of the rails was 50 pounds 
per yard, and they had been three years laid. ‘The experiments. 
were made with four first-class carriages, weighing each, when 
unloaded, 3 tons 16 cwt. Each carriage was supported on two 
pair of 3-feet wheels. Each pair of wheels with their axle 
weighed 8 cwt. 

During the experiments a wind of moderate force blew down 

the plane. The velocity of the wind was not ascertained. The 
weather was fair, and the rails clean and dry. 
_ The gross weight of the four carriages in the first and second 
experiments was 15°6 tons. After the second experiment a 
weight was added by placing iron chains in the carriages, which 
rendered the gross weight of the train 18°05 tons, which was 
estimated to be equivalent to their weight when transporting 42 
passengers. 

The total frontage presented by the foremost carriage was 
62 square feet, including the vertical cross section of the wheels. 
The cross section of all the carriages was the same, and the di- 
stance between the carriages when coupled was 3 feet 10 inches. 
They were coupled by the patent couplings of Mr. Booth. 

The train was placed on the summit level of the Liverpool 
and Manchester Railway, at about half a mile from the post 0, 
which marked the commencement of the plane. It was drawn 
by an engine so as to give it a considerable speed. On ap- 
proaching the stake 0 the engine was detached, and the train 
was allowed to descend by gravity only, the engine proceeding 
down the plane so much faster as to be considerably in advance 
of the train. 

The results of the experiments are given in the following table. 
The first column in each experiment gives the time of passing 
each successive stake, as taken down, without any reduction for 
errors of observation, however apparent. In the second column 
the differences, or the times of passing over each successive hun- 
dred yards, are given. In the third column these differences are 
averaged, so as in some degree to obliterate the errors of the ob- 
served times of passing the successive stakes. At the foot of the 
table the mean time of moving over a hundred yards taken from 
the entire time of descending the plane is given. 


RAILWAY CONSTANTS. — 


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226 EIGHTH REPORT—1838. 


After passing the 27th stake the train was in each experiment 
allowed to run until it came to rest. The-distances which it 
ran beyond the foot of the plane and the times were as follows. 


Distance. Time. 

: Feet. Seconds. 
Piveriment 1.0 «Jc. a! 6270 372 
Fexperiment Wi... bs, .. .« _ 6870 360 
Experiicht isle so. -. Se faeO 384 
Experiment iV... 9... 5 F620 393 
Hxperinent Vo = |. 62 ss F410 382 


The time of passing each mile post from the 27th stake, at the 
foot of the plane, until the train came to rest was also observed, 
and is given in the following table, as well as the levels of the 
successive posts. 


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In the first two experiments, with the gross load of 15°6 
tons, no acceleration is apparent in the descent. In the first 
the velocity fluctuated between 100 yards in 6 and 100 yards in 
7 seconds, the mean being 100 yards in 6°48 seconds. In the 
second experiment the limits of the varying observed speed are 
more narrow, being 100 yards in 6§ seconds and 100 yards in 
7 seconds, the mean being 100 yards in 6°61 seconds. ‘The 
mean result of these two experiments is 100 yards in 6°55 se- 
conds, or 45°8 feet per second. 

Tn the last three experiments a slight acceleration is apparent 
in the first thousand yards of the descent, but the subsequent 
variations of speed are too minute and irregular to be ascribed 
to anything save the casual inequalities of the rails and the in- 
evitable errors of observation. 

The time of moving down the last thousand yards in the third 
experiment was 61 seconds, in the fourth 60 seconds, and in 
the fifth 61 seconds. We cannot, therefore, be far from the 
truth if we assume that the train loaded, as in these experi- 
ments, with 18°05 tons gross would continue to descend a plane 
falling 1 in 96 with the velocity of 1000 yards in 602 seconds, 
or 49°45 feet per second. 

Thus, then, it appears that the uniform velocities attained by 
the same train of coaches loaded with 15°6 tons and 18°05 tons 
was 45°8 and 49°45 feet per second respectively. 

It will be evident from the formula (25.) that if the resistance 
of the air vary in the ratio of the square of the velocity within 
the limits of the experiments, the gross weights of the same 
train differently loaded ought to be in the ratio of the squares 
of the uniform velocities attained by it in descending the same 
plane, the effect of the wind being supposed to bear an incon- 
siderable proportion to the whole resistance at this speed. For 
let M and M’ be the two loads and V and VY’ the two uniform 
velocities, we shall then have 


Mftav?=MAh 
Mf+aV®=M’'h 


228 EIGHTH REPORT—1838. 


“rT PME 
M > Vv 
In the present case 
M 15°60 
—_ = = 0°864 
M! 18°05 
ig (458)? 


RAILWAY CONSTANTS. 239 


From which it appears that the resistance in this case is very 
nearly proportional to the squares of the velocities. 
By substituting for M and A in (25.) their values in these ex- 
periments, we find that M2 = 364lbs. in the first two experi- 
ments, and M h = 421 lbs. in the last three experiments. 
Hence it follows, that at the speed of 45°8 feet per second, 
or 31°2 miles per hour the resistance of this train of four first- 
class carriages, weighing 15:6 tons gross, was 364 lbs., and at the 
speed of 49°45 feet per second, or 33°72 miles per hour, the re- 
sistance of the same carriages loaded so as to amount to 18°05 
tons gross was 421 lbs.; being in each case at the rate of 233 lbs. 
per ton. 
Since the effect of the wind must, in these experiments, have 
rendered the resistance less than it would have been had the 
atmosphere been calm, it may be inferred with certainty, that 
' the resistance of a train of four first-class carriages, carrying 
the weight of their usual complement of passengers at 337 miles 
an hour on a level and straight railway in calm weather, must 
be greater than 421 pounds, or 235 pounds per ton. 
Consequently, for such a load moved at such a speed, the 

angle of resistance, or the inclination which in its ascent would 
double the resistance, and in its descent require no moving 
power, is greater than 54. 
- If the weather had been calm when these experiments were 
_ made, the distance which the train ran in each case before it 
came to rest, after leaving the foot of the plane, would have 
supplied means of obtaining a tolerable approximation to the 
proportion in which the whole resistance ought to be assigned 
to each of the two causes—that which is independent of the 
velocity, and that which is proportional to its square. 

. As it is intended to repeat these experiments in calm weather, 
it may be worth while at present to investigate the formule by 
which such an approximation may be obtained. 

The symbols in (22.) and (25.) retaining their signification, 
and d! expressing the gradient of the line extending from the 
foot of the plane down which the train has been supposed to 
have descended with a velocity rendered uniform by the resist- 

ance, we shall suppose this uniform velocity to be expressed 
by V'; and since the train is allowed to run until it is brought 
to rest by the resisting forces, we shall have V = 0, and S = the 
distance from the foot of the plane to the point where the train 
stops. Making the reductions consequent on these conditiens 
the equations (22.) and (25.) become 
QagS _ (hth! 
M + M! hif 
VOL. VII, 1838, — Q 


Pa) 


230 EIGHTH REPORT—1838. 


Mf+aV? = Mi 


Eliminating a, we obtain J 
hl 


lates 
2MSg(l—f) _ nf __4 

(M+ MV? 
a pe 


(M + M’) V? 


pa As RE | 
2MSgh somes: 


For brevity let p = 


Let 


and we have 
US. 0 Wb Bea trp noe een) 


This equation would be satisfied by f= /'; but that would 
involve the condition V! = 0, and therefore cannot be admitted. 

The data necessary for the calculation of p will be obtained 
by the experiments and by the levels of the line beyond the 
foot of the gradient A’. There are also practical limits between 
which it is certain that the mean value of f must be included. 
Thus it is certain that f is not greater than 0°0050, and it is 
equally certain that it is not less than 0-0015. If, then, the equa- 
tion (28.) be tabulated between these limits, taking differences 
sufficiently small to give the necessary approximation, the values 
of f may be obtained corresponding to those values of the several 
quantities, M, M', V', &c. which are given by the experiments. 

In the case of the Whistcn plane, the line rises from the foot 
of the plane at the mean rate of 1 in 936. We shall have, there- 
fore, the following values for the quantities on which p depends 
in the first two experiments, the value of M!' having been de- 
termined by experiments made on the oscillation of the wheels; 


M=156 M=1:86 g = 32°16 h= a Wie 458, 


The mean of the distances from the foot of the inclined plane to 
the points where the train stopped in the first two experiments 


RAILWAY CONSTANTS.: 231 


is 6570 feet. If a quarter of a mile be deducted for the increase 
of this distance produced by the effects of the wind, the reduced 
value of S would be 5250 feet, which, combined with the above 
values of the other quantities, would give p = 6°508, and the 
corresponding value of f would be 0:00274. 

In the last three experiments we have M! as before, and 
M = 18°05. The mean value of V! is 49°45, and the mean value 
of S = 7520 feet, from which, if a quarter of a mile be deducted 
as the effect of the wind, we shall have S = 6200. Hence 
p = 6'331, and f = 0-00249. 

If a mean be taken between the two values of f thus found, 
we shall have 


1 
= 0°00261 = —. 
f 383 


This value of f is in accordance with the approximation obtained 
_ from the experiments of M. de Pambour. 


The next set of experiments which demand attention were 
made upon the Grand Junction Railway. 

The section of the Grand Junction Railway from Madeley to 
Crewe is as follows: 


Length of Plane.|| Fall. |Rateper mile.| Gradient. 
Station. a _———— 


M4) °C. | i, One in 

t Madeley ... 
q Charlton ... | 3 | 20 | 90 |) 97-28 29°83 178 
Basford ... | 3 3 | 72 || 60-68 19°92 265 


Crewe ...... 1 | 31 | 31 || 22-26 16°00 330 


_ This series of planes was staked out in the following manner : 
__astake marked 0 was placed at the foot of the plane at Charl- 
_ ton, at the point where the gradients of | in 178 and 1 in 265 
meet. The plane ascending towards Madeley was divided into 
‘spaces of 100 yards by 57 stakes, numbered 1, 2, 3, &c., up- 
| wards from the stake 0; and the plane falling 1 in 265 from 
| Charlton towards Basford was also divided into like spaces by 
| 17 stakes, numbered 1, 2, 3, &c., to 17, commencing from the 
| Stake 0, the remainder of the line to Crewe being divided by 
-quarter-mile-posts. 

_ Five merchandise wagons were loaded with iron chairs, so as 
to weigh precisely six tons each gross. The empty wagons 
weighed iwo tons each. 

These wagons were constructed with high sides and ends, 
capable of being removed and laid flat upon the platforms of the 
Wagons, so as to expose a greater or less bulk of carriage alter- 

Q 2 


932 EIGHTH REPORT—1838. 


nately to the air. The transverse section of these wagons is 
represented in the annexed figure. The rectangle A B F KE re- 
presents the moveable end, which, when the frontage of the wagon 
is required to be diminished, is laid flat upon the platform. The 


B 


> 


318°" 


whole frontage, composed of the rectangle A B D C, and the 
transverse section of the framing, wheels, springs, and axle, 
amounts to 47°8 square feet, which, when the high sides are 
lowered, is diminished by the magnitude of the rectangle ABF E. 
This latter being twenty-four square feet, it follows that the 
transverse section with the high sides has very nearly double 
the magnitude of the transverse section when the sides were 
lowered. 

Immediately before the experiments, the wagons had been 
taken a distance of thirty miles, from Warrington to the Made- 
ley summit, so that the axles might be expected to be in good 
running order, and the grease properly melted and supplied. 

‘The weather was fair and quite dry, with a breeze from the 
north blowing almost directly up the planes, and therefore in- 


creasing the resistance of the air. The rails were clean, and 
the line had previously been accurately levelled from stake to 
stake. 
The other members of the Committee being absent, the fol- 
lowing experiments were made by Mr. Hardman Earle, Mr. 
Edward Woods, engineer of the Liverpool and Manchester Rail- 
way, and Mr. Alfred King. 
The line changes its direction by curves, all of which have a 
radius of a mile at the parts marked in the following table with 
an asterisk. 
In conducting the experiments, the train of wagons was al- 
lowed, in each case, to pass without interruption from gradient 
to gradient, the time of passing each successive stake being ob- 
served and recorded. But as the motion on the different gradi- 
ents are essentially distinct experiments, they have been sepa- 
rately tabulated and reduced. In experiment I. the train was 
brought to the stake No. 33 on the plane falling 1 in 178, and 
allowed to descend by gravity from a state of rest. It was al- 
lowed to move on the next gradient until it reached the seven- 
teenth stake, where it was stopped by the brake. 
In experiment II. the same train, in the same state, was 
placed at the fifty-seventh stake, at the summit of the plane, 
falling 1 in 178, and was allowed, as before, to descend by gra- 
vity from a state of rest. It moved along the successive gradi- 
ents, and finally stopped 364 yards beyond the 514 mile-post, 
~ on the gradient falling 1 in 330. 
: In experiment III. the high sides of the wagons were taken 
down, and laid on the platforms of the wagons, so as to reduce 
the surface exposed to the air without altering the gross weight 
of the train. The train was then started again, as in the second 
_ experiment, from the fifty-seventh post, and it descended the 
successive gradients, and finally came to rest on the level at 
three yards beyond the fifty-fourth mile-post. 
_ In the second and third experiments the train was started 
from the same point; in the one case it came to rest at 10,019 
yards from the point of its departure, and descended 139 feet, 
and in the other case it came to rest at 14,058 yards from the 
point of its departure, and descended 175 feet. 

Th the following table the results of the three experiments on 
the gradient of 1 in 178 are exhibited in the same manner as in 
the table of the experiments on the Whiston plane already given, 


RAILWAY CONSTANTS. 233 


Total fall 
in feet 
Fall per 

100 yards, 


10:21 |1-73 


~ 
bo DH OO et Or 


ASARANAVE 
NYDRAR EH AAD 


os 


SAVWAMVAIAAGCIS 
BR Om © 


AARNAAANGD 
on 


<i 


Gs 
“I 
i=) = 
i=) 
a ikcity, aly. aterimiwa) oe 5 5 5 


"67 
62°76 |1-83 
64°28 |1-52 
66:01] |1-73 
67°61 |1-60 
69°31 |1-70 
71:08 |1:72 
72-71 |1°68 
74-41 |1:70 
75°98 |1°57 
77°67 |1-69 
79°31 |1-64 


82°92 |1:98 
84-68 |1-76 
86°21 |1:53 
87°89 |1°68 
89:50 |1°61 
91°13 |1°63 
92°83 |1-70 


95°96 |1-48 


ob 


= 


80°94 |1°63 |) 


94-48 |1-65 |, 


EIGHTH REPORT—1838. 


Experiment I. 


Time of 
Passing. 


-j/|m s 


| 
Diff. 


Ss 


122: 
45°5 
34:5 
29 

26°5 
25 

23°5 
21°5 
21 

20°5 
20°5 
20 

18-5 
185 
175 


33°5 
16 
16 
155 
155 
15 
13°5 
14 
14 
145 
13°5 
13°5 
14 
13 
14 
13 
13 


Mean. 


Time of 
Passing. 


Experiment IT. 


Experiment III. 


Diff. | Mean. 


13 {18 


12 {12-08 


12-5 |12-5 


12-5 |12-02 
12 

12 

12 

12 

12 

12 |12 
125 
125 

11 

12 

12 

12 


12 

12 {12 
12 

12 {12 
11 

125 


11:5 |12 


Time of 


Passing. Diff. 
m § Ss 
37 (0 
39 7-5 127-5 
40 5 | 575 
5] 46 
41 32 | 41 
42 105} 38°5 
45 | 345 
43.17 | 32 
48 | 31 
44 175 | 29°5 
46 | 28°5 
45 13 | 26 
40°5 | 27°5 
46 6 | 25°5 
31 25 
54:5 | 22-5 
47 17 | 22°5 
38 | 21 
58 | 20 
48 17 19 
35°5 | 18°5 
53 | 175 
49 10:5 | 17:5 
27-5 | 17 
43 15-5 
58 | 15 
50 13 15 
27-5 | 14:5 
41 13°5 
54 13 
51 7 13 
20 13 
32°5 | 12:5 
44-5 | 12 
56 | 115 
52 8 12 
19-5 | 11:5 
30°5 | 10°5 
42 | 115 
52°5 | 10-5 
53 3:5] 11 
14 10°5 
24:5 | 10°5 
34:5 | 10 
44:5; 10 
55 | 10°5 
54 5 10 
15 |:10 
25° | 10 
35 10 
44-5} 95 
54 9°5 
55 4 10 
13 9 
23 10 
32°5| 9:5 
42 9°5 
51 9 


Mean. 


Ss 


10°66 


10-16 


9°83 


9:5 


-RAILWAY.CONSTANTS. 235 


In the first experiment the motion was continually accele- 
rated, until the train passed to the succeeding gradient. The 
acceleration was rapid at first, but gradually lessened as the 
speed increased, proving a continual augmentation of the re- 
sistance. For the last thousand yards of the plane, the accele- 
ration became very small in amount, showing a tendency to an 
uniform speed, and therefore to an equality between the moving 
force and the resistance. 

In the second experiment, the train being started from the 
fifty-seventh stake, a more’ extensive space was allowed for the 
action of the gravity of the inclined plane. Throughout the 
first 3300 yards the motion, as nearly as possible, corresponded 
with the motion of the train in the first experiment, the velo- 
city at corresponding posts being nearly the same. The rate 
of acceleration, as before, gradually diminished, until the train 
arrived at the twenty-eighth stake, from which to the foot of 
the plane the motion was sensibly uniform. From the twenty- 
eighth to the eighteenth, the rate of motion is 100 yards in a 
small fraction above 12 seconds, and from the eighteenth stake 
to the foot of the plane the motion is uniformly 100 yards in 12 
seconds, being at the rate of 25 feet per second, or 17 miles an 
hour. 

Hence it follows, that with this train of five wagons, weigh- 
ing 30 tons gross, with high sides, and presenting a frontage of 
47°8 square feet, the whole resistance, at a speed of 17 miles an 
hour, was equal to ;+,th part of its weight, or 377 lbs., being 
at the rate of 12°6 lbs. per ton. 

In the third experiment, in which the high sides of the wa- 


_gons were taken down so as to reduce the frontage or end sur- 


face of the train to 23°8 square feet, the motion continued to be 
accelerated to the foot of the plane; but for the last 1000 yards 
the acceleration is so little as to be barely sensible. There is 
a tendency to an uniform velocity of 100 yards in 9 seconds, or 
33°3 feet per second, being at the rate of 222 miles per hour. 

If this be assumed as the uniform velocity which the train 
would have attained had the plane preserved an uniform incli- 
nation for a sufficient distance, it will follow that its resistance 
at this speed, with the reduced frontage, was equal to its resist- 
ance at 17 miles an hour with the larger frontage. 

Thus, with the same expenditure of tractive power, a dimi- 
nution of frontage in the ratio of 2 to 1 nearly gives, in this case, 
an increase of speed in the ratio of only 25 to 33°3. 

After descending the plane of 1 in 178, the train in each ex- 
periment moved along the next plane, the average descent of 
which is 1 in 266. The first 1700 yards of this inclination was 


236 EIGHTH REPORT—-1838. 


staked at intervals of 100 yards, and the 503 mile-post from 
Birmingham was 55 yards beyond the 17th stake. The re- 
mainder of the plane was divided by quarter-mile posts. In the 
following table the times of passing the successive posts in each 
experiment and their differences are given. In the column of * 
mean differences the mean time of traversing a hundred yards 
is given, the means being taken at intervals as in the former 
tables. 


eg 3 Eo ¥ Experiment I. Experiment IT. Experiment III. 
SORE RN ECL M | Cormeen ae | OO E 
Ze 3 22a || Time of | pitt.) Mean. aS Diff. | Mean, | pime Of | Diet.) Mean, 
feet. | feet. ||m s S s m s s S m s s s 
0 4 44 55 51 
1 1:37 | 1:37 || 5 20:5 55 j11 56 0 9 
2 2°59| 1-22 345 |14 5 7 {12 9 9 9 
3 3°64| 1-05 47 125 19 {12 {11-7 18°5| 9-5 
4 4:72) 1:08 || 6 1 |14 |138°5 32 {13 28:5 10 | 9°75 
a 5°79 | 1:07 15 =|14 44 |12 38 9-5 
6 6°59 | 1-10 30 {15 56°5 |12°5 |12-5 48 |10 9-75 
7 7:95 | 1:06 45 |15 |147 | 6 9 |125 58 |10 a 
8 9:00} 1:05 || 7 O {15 23 |14 {12:2 57 7:5) 9-5!) 9:75) 
9 {10°14} 1:14 15-5 |15°5 37 «(|14 18 {10-5 
10 /11:24) 1:10 31-5 |16 |15°5 51 |14 28 {10 {10°25 
1] {12°38} 1:34 47 |15°5 7 4:5 |13°5 |13-7 38°5 |10°5 
12 |13°40/ 1:02 || 8 35/165 18-5 |14 49 {10-5 |10°5 
13 |14°65 | 1:25 20 |16°5 |16-2 33 |14:5 59-5 |10°5 
14 {15°79} 1:14 36°5 |16°5 47-5 \14°5 |14°3 95 |10 {10-5 
15 16°95) 1:16 52°5 |16 8 2 |14°5 20 |10-5 
16 |18:25/ 1:30 || 9 9 /|16°5 |16-6 W7 {15 31 jll 
17 {19:22 0:97 27 =(|18 32 115 (14:8 41 |10 |10°5 
504 |19°28} 0:06 44 |17 40 8 47 6 
4*/24°36 | 5:08 9 50-5 |70°5 |16 59 34 |47 |106 
$%/29-44 | 5:08 ll 6 |75°5|17-:2 || 0 22 |58 {13-2 
51 |384:52| 5-08 12 45 (99 |22-6 117 {35 
1 |39-60| 5:08 14 31 |10°6\24:1 | 2 0 |43 {11:8 


In the first experiment there is a gradual retardation, which 
continues until the train is stopped by the brake. At all the 
velocities, therefore, which it attained, the resistance to its mo- 
tion was greater than its gravity down the plane. 

In the second experiment, where a greater extent of the plane 
is given for the motion, the retardation is also continued until © 
the train passes to the succeeding gradient. The average speed 
of the train for the last quarter of a mile is 100 yards in 24°1 
seconds, or 12°4 feet per second, being at the rate of 8} miles 
an hour. Hence we infer that the resistance to the train at this 
speed was greater than its gravity down, 1 in 266, which is 
equivalent to 8°5 lbs. per ton. The total resistance of this train 
of 30 tons, was therefore greater than 255 lbs. at 8} miles an 
hour. 


RAILWAY CONSTANTS. 237 


In the third experiment, in which the end surface was dimi- 
nished, the train attained an uniform velocity at the 10th 
stake of 100 yards in 10% seconds, or 28°6 feet per second, 
or 194 miles an hour, which it preserved to the foot of the 

lane. The resistance, therefore, at this speed with the dimi- 
nished end surface was 8°5 lbs. per ton, and the total resistance 
was 255 lbs. 

It appears, therefore, that with the frontage of 47:8 square 
feet this train suffered a greater resistance at 83 miles an hour, 
than that which it sustained with the lesser frontage of 23°8 
square feet at 194 miles an hour. 

In the second and third experiments the train continued to 
moye on the succeeding gradients, and the circumstances of its 
motion are exhibited in the following table. The gradient of 
1 in 330 and the succeeding level are straight. 


Average Experiment II. Experiment III. 
No. of Posts.| Gradient, eee alse oe kernal Chi as 
omen’ | gamee | pin | Rimeet | pie 
m s§ § m § Ss 
513 330 14 31 2 0 
x 330 17 9 158 2 50 50 
s 330 21 24 25°5 3 40 50 
52 330 4 31:5 515 
+ 330 5 24 52-5 
& 330 6 18 54 
g 330 7 15 57 
53 330 8 16 61 
4 330 9 22°5 66°5 
z 330 10 35 725 
% level. 11 52 V7 
54 level. 14 40 168 
+3 yards.) level. ll 55 15 


It appears, therefore, that with the greater frontage the train 
came to rest after having proceeded half a mile on the gradient 
of 1in330. With the diminished surface the motion was gradu- 
ally reduced to the foot of the gradient of 1 in 330, the average 
speed on the last quarter of a mile of that gradient being 109 
yards in 72°5, or 4°14 feet per second, being nearly three miles 
an hour. It may therefore be inferred that with the lesser sur- 
face, at very slow rates of motion, the resistance was somewhat 
greater than the gravity down an inclination of 1 in 330. This 
resistance is at the rate of 6°8 lbs per ton, and the total resist- 
ance for the train of 30 tons was therefore greater than 204 Ibs. 

It may be observed that this result is quite in accordance 
with those already obtained in p. 211 and p. 231, from the ex- 


238 EIGHTH REPORT—1838. 


periments down the Whiston plane, and from those of M. de 
Pambour on the Sutton plane. 

In considering these experiments, and in deducing from them 
any inferences of a general nature, it is of importance to re- 
member that in all of them a wind of unascertained force blew 
up the planes, and therefore against the motion of the train. 

It may be observed that in these experiments no_ perceptible 
effect is produced by the curves. The uniform velocity of the 
train in the second experiment is the same before entering on 
the curve which commences at the 17th stake on the gradient of 
1 in 178, and after passing the 5th stake, where the line becomes 
straight. 

From all these experiments it is apparent that a train of rail- 
way carriages in descending an inclined plane is subject to a re- 
sistance which is continually augmented as its motion is acce- 
lerated, and that if the plane have sufficient length, this resist- 
ance will at some certain speed become equal to the gravitation 
down the plane, and then all further acceleration must cease. 
This conclusion will be corroborated, and indeed put beyond all 
doubt by other experiments which are still to be reported. It 
will be evident, therefore, that if the train on which the experi- 
ments were made be started from a point ata sufficient distance 
from the foot of the plane, the velocity which it will have when 
it leaves the foot of the plane and commences to move along the 
next gradient will be the same, whatever may be the point from 
which it may have been started. 

Let A B be the inclined plane down which the train is moved, 
and let BC be the succeeding gradient. Let S be a point 


from which the train being started it will acquire the uniform 
speed before it arrives at B. Then, if it be successively started 
from S', S!', or any other point still more distant from B, it will 
have, on arriving at B, the same velocity. It will, therefore, in 
all cases move on B C to the same point before it be brought to 
rest. Let this point be R. 

According, then, to the method of determining the resistance 
adopted by M. de Pambour (p. 199.), the amount of resistance 
obtained when the train is started from S would be equal to the 
gravity on the inclination S R; if started from S', it would be 
equal to the gravity on the steeper plane S’ R; if started from 


RAILWAY CONSTANTS. 239 


S", it would be equal to the gravity on the plane S" R; and, ina 
word, the value of the resistance according to this method might 
be found to be of any amount whatever. 

The experiments were next directed to the trial of the move- 
ment of trains of coaches down the series of planes extending 
from Madeley to Crewe, already described, and were conducted 
by Dr. Lardner. A train consisting of one first-class and three 
second-class close coaches, were loaded in the same manner as 
the train of first-class coaches used in the experiments already 
described upon the Whiston plane, the gross weight being 18 
tons. The second-class coaches differed in nothing but the 
structure of their body from the first class, their transverse sev- 
tion being nearly the same. In addition to the fifty-seven stakes 
by which the plane falling 1 in 178 had been divided, a fifty- 
eighth stake was placed at the top of the plane, the inclination 
being found to extend 100 yards higher than fifty-seventh stake. 
The direction of the line was nearly due north and south, and 
the wind was from the south, and therefore blowing directly 
down the plane. No means of ascertaining its velocity could 

be procured at the time. The train was in each case pushed by 
an engine to the fifty-eighth stake, and there dismissed to de- 
scend the plane by gravity. The time of passing the successive 
stakes was observed as in the former experiments. In the first 
two experiments, given in the following table, the entire train 
was dismissed down the plane, the carriages being coupled 
by Mr. Booth’s patent couplings. In the third experiment the 
first-class carriage and one of the second-class carriages, coupled, 
were used ; and in the fourth experiment the other two second- 
class carriages. The entire transverse section of the carriages, 
including the frame, wheels, and axles, was 61 square feet, and 
the distance between carriage and carriage, when coupled by the 
patent couplings, was 3 feet 10 inches. 


240 EIGHTH REPORT—1838. 


s 
| a Experiment I. || Experiment II. || Experiment III. || Experiment IV. ; 
PI g| 5 pr a grt beh 
3 5s| 2 sled Jad + sled) sled 
we So] 2 SiB& S\B 51. lla 
= Tait a= ‘3 ||Time of BSE Time of Ses Time of Eg 62 Time of SBS 
A gS 3 Passing ole s|| Passing |" ojas Passing Soles Passing Soles 
Zz Sita Stakes, |5 9) ¢—|| Stakes. |59|)3 5 Stakes, Aols= Stakes. aul 
“| Bas a Stas Ba 8 
n n n DM 
feet. |fect m s m s m s m s 5 
58 49 58 11 36 30 10 
56*| 1°63 |1°63 36 (16 37 13 12 4 | 14 35 | 13 
55*| 3°36 1°73 48 |13 31 {18 18 | 14 48 | 13 
54*| 5°06 |1°70 5) 1 {12 44 13 33 | 15 31 4 | 16 
53*| 6°68 (1°62 12 {ll 54 [10 48 | 15 20 | 16 
52*| 8°48 |1°80 11769 22 |10 38 4 |10 13 3 | 15 34 | 14 
51*| 10°21 |1°73 32 |10 12 |8 1g | 15 49 | 15 
50*| 12°06 |1°85 41 |9 |10°4 22 {10 |10°2 34 | 16 |15°2|| 32 4 | 15 115°2 
49*| 13°57 |1°51 50 |9 31 | 9 49 | 15 19 | 15 
48*| 15°30 |1°73 59 | 9 40 | 9 143 | 14 33 | 14 
47*| 16°98 |1°68/176°5|| 52 7 | 8 50 {10 18 | 15 49 | 16 
46*| 18°70 |1°72 12 | 5 59 |9 34 | 16 33 4 | 15 
45%| 20°38 |1°68 26 114 |9 ||39 7 |8 |9 50 | 16 |15°2 19 | 15 |15 
44%) 22°04 |1°66 36 |10 17 {10 15 4 | 14 37 | 18 
43%) 23°49 |1°45 45 | 9 27 1/10 20 | 16 54 | 17 
42%] 25°40 |1°91 |178'1 54 19 37 |10 36 | 16 3410 | 16 
41*|27°14 |1°74 53 3°5| 95 45 |8 51 | 15 28 | 18 
40*| 28°79 |1°65 13 | 9°5| gr4 55 |10 | 9°6|| 16 5 | 14 |15 43 | 15 |16°8 
39*| 30°53 (1°74 23 {10 40 4 /9 21 | 16 58 | 15 
38%*| 32°11 |1°58 33 {10 13°5 | 95 38 | 17 35 14 | 16 
37*| 33°78 |1°67 |179°0 43 {10 23 | g'5 53 | 15 29 | 15 
36*] 35°50 |1'72 53 {10 33 |10 17 8 | 15 44 | 15 
35 | 37°09 |1°59 54 3 {10 /10 43 |10 | 9°6 24 | 16 |15°3)) 36 3 | 19 /16 
34 | 38°82 |1°73 13 |10 52 | 9 40 | 16 23 | 20 
33 |40°54 |1°72 23 {10 41 1/9 56 | 16 40 | 17 
32 | 42-24 |1°70 |177°3 33 |10 10 | 9 18 12 | 16 58 | 18 
31 | 43-87 |1°63 43 {10 20 |10 28 | 16 97 15 17. 
30 | 45-81 |1°94 53 |10 {10 30 {10 | 94 34 | 16 /16 31 | 16 /17°6 
29 | 47:49 |1:68 55 3 |10 40 |10 19 0 | 16 47 | 16 
28 | 49-23 |1°74 13 {10 50 |10 14°] 14 38 2 | 15 
27 |50°87 |1°64|173°8 23 {10 42 0 |10 30 | 16 17 | 15 
26 | 52°51 |1°64 34 {11 9 |9 45 | 15 g2 | 15 
25 | 54°12 |1°61 44 |10 |10°2 19 |10 | 9°8|| 20 0 | 15 |15°2 47 | 15 |15'2 
24 | 55°89 11°77 54 10 29 |10 Tbe yes 39 5 | 18 
23 |57°58 |1°69 56 4 {10 39 |10 - 30 | 15 18 | 13 
22 |59°25 |1°67 |179°0 24 10 48 |9 45 | 15 32 | 14 
21 | 60°93 |1°68 24 110 58 10 21 0 | 15 48 | 16 
20 | 62°76 |1°83 34 {10 |10 || 43 7 |9 | 96 15 | 15 |15 || 40 0 | 12 |14°6 
19 | 64°28 [1°52 44 |10 16 | 9 30 | 15 Loy pikes 
18 | 66°01 |1°73 54 {10 26 |10 45 | 15 30 | 15 
17*| 67°61 |1°60|179°4|| 57 3 | 9 36 10 22 0 | 15 30 | 14 
16*| 69°31 |1°70 13° |10 45 |9 14 | 14 58 | 14 
15*| 71°03 |1°72 23 {10 | 9°8 55 10 | 9°6 28 | 14 /14°6)| 41 10 | 12 [14 
14*| 72°71 |1°68 33 |10 44 4 19 42 | 14 26 | 16 } 
13*) 74°41 |1°70 42 |9 13 | 9 56 | 14 40 | 14 
12*| 75°98 |1°57 |179°2 52 |10 23 {10 23.10 | 14 53 | 13 
11*| 77°67 |1°69 58 2 {10 33 {10 24/14 42 8 | 15 
10*| 79°31 |1°64 11 | 9 | 96 43 }10 | 9°6 38 | 14 |14 20 | 12 /14 
9*| 80°94 |1°63 21 {10 52 |9 51 | 13 34 |14 
8*| 82°92 |1°98 31 /10 45 1 |9 24 4 /13 47 | 13 
7*) 84°68 |1°76 |172"4 40 |9 10 | 9 17 | 13 43 0 | 13 
6*| 86°21 |1°53 50 {10 20 {10 30 | 13 14/14 
5*| 87°89 |1°68 59 0 /10 | 9'8 30 |10 | 94 43 | 13 |13 26 | 12 |15°2 j 
4 | 89°50 |1°61 9 |9 39 | 9 43 38 | 12 { 
3 |Q1'13 |1°63 19 |10 49 |10 43 52 | 14 
2 |92°83 |1°70 |184°0 29 |10 58 | 9 43 44 4 | 12 
1 | 94°48 |1°65 39 {10 46 7 |9 43 18 | 14 
0 1°48 |191°7 48 | 9 9°6) 17 {10 | 9°4/) 25 49 | 66 13°2 | 32 | 14 |13°2 


In the first and second experiments made with the train of 
four coaches, it will be observed that after having descended 
800 yards, a velocity of 100 yards in nine seconds was acquired, 
which underwent a very slight diminution throughout the middle 


* The divisions thus marked are curves having a radius of a mile. 


a 


‘i 
rN : 

ae. 

ba a 


etal 


RAILWAY CONSTANTS. 241 


of the plane, and subsequently a very slight increase. These 
fluctuations were, however, so small that they may fairly be 
attributed to the varying effects of the wind arising from the 
different exposure of the train in cuttings and on embankments. 
The velocity, therefore, may be regarded for nearly 5000 yards 
as practically uniform, the mean rate in the first experiment 
being 100 yards in 9°74 seconds, or 30°8 feet per second, which 
is equivalent to twenty-one miles per hour; and in the second 
experiment 100 yards in 9°95 seconds, or 31°6 feet per second, 
being 213 miles per hour. The mean of the two will give a ve- 
locity of 51-2 feet per second, or 214 miles per hour. Hence it 
appears that the resistance of this coach train, at a velocity of 
21; miles an hour, is the 178th part of its weight, or 226°8 
pounds, being at the rate of 12°6 pounds per ton of the gross 
weight. 

In the third experiment made with the first-class carriage 
and one second-class carriage coupled, the speed commencing 
from the summit was 100 yards in fourteen seconds, which was 
gradually diminished to a point beyond the middle of the plane, 
where it was reduced to 100 yards in sixteen seconds. It then 
slightly increased to 100 yards in thirteen seconds, which was 
maintained uniform for the last 1000 yards. In the fourth ex- 


_ periment with the second-class carriages, the initial velocity 


at the top of the plane was 100 yards in twelve seconds, which 
was gradually diminished,till at the middle of the plane the ve- 
locity was 100 yards in 173 seconds, after which it was gradually 
but slightly increased to the foot of the plane, where the final 
velocity was the same as in the third experiment. Considering 
the lightness of the trains and the consequently increased effect 
of the wind, these fluctuations of speed probably arose from the 
varying shelter and exposure of cuttings and embankments in 
thedescent. In the third experiment the mean velocity through 
5000 yards was 100 yards in 14°7 seconds, or 20°4 feet per se- 


cond, being at the rate of 13°91 miles per hour. In the fourth 


experiment it was at the rate of 100 yards in 15°16 seconds, or 


_19°8 feet per second, being at the rate of 13°5 miles per hour. The 


mean of these two is 201 feet per second, or 13°7 miles per hour. 
Now it follows that, the wind being with it, this train of two 
coaches suffered a resistance, the total amount of which, at 13°7 


‘miles per hour, amounted to the 178th part of their gross weight, 


or to 113°4 pounds. 

The train of four coaches after having descended the plane 
falling 1 in 178, as described in the first two of the preceding 
experiments, was allowed to continue its motion on the succeed- 
ing plane, falling at the mean rate of 1 in 266, and extending to 
a distance of 5360 yards from the foot of the former plane. 


= particulars of these experiments are given in the following 
table, 


8-01 


EIGHTH REPORT—I838. 


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RAILWAY CONSTANTS. © 243 


In the first experiment the train moved over this gradient 
with a gradual retarded motion, commencing with the velocity 
with which it left the former plane, and gradually diminishing 
in speed until it attained the rate of 100 yards in 16°36 seconds, 
with which speed it passed on to the succeeding gradient. In 
the second experiment the train, in like manner, was retarded 
till it attained the velocity of 100 yards in 14:32 seconds, with 
which it passed to the succeeding gradient. The difference be- 
tween the final velocities in descending this gradient in the two 
experiments must be ascribed to the varying force of the wind, 
since the train in both was the same, and the initial velocity 
was not materially different. The mean of the two final velo- 
cities is 100 yards in 15°34 seconds, or 19°55 feet per second, 
being at the rate of 13°3 miles per hour. 

__ Since, then, this train in descending the gradient 1 in 266 had 
not yet ceased to be retarded, having attained the velocity of 
19°55 feet per second, it follows that at this velocity the resist- 
ance to the train must have exceeded its gravity down that 
gradient. 

| It was now determined to try the effects of four carriages 
~ moved separately down the inclined plane falling 1in 178. The 
_ carriages were therefore separately pushed to the summit of the 
~ plane and dismissed from it at a high speed, the times of pass- 
a the successive posts being observed as in the former case. 


‘The results of these four experiments are exhibited in the follow- 
ng table. 
= 


244 EIGHTH REPORT—1838. 


Experiment I. || Experiment IT. || Experiment III. |; Experiment IV. 


Time of 
Passing 
Stakes. 


No. of Stake. 
Fall from 
Stake to Stake. 


Time from 
Stake to Stake. 
Mean Time 
per 100 yards. 
Time from 
Stake to Stake. 
Mean Time 
per 100 yards. 
Time from 
Stake to Stake. 
| Mean Time 
per 100 yards. 
Time from 
Stake to Stake. 
Mean Time 
per 100 yards. 


z | 
stem Gradient, onein 


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* The divisions thus marked are curves having a radius of a mile. 


RAILWAY CONSTANTS. 245 


In the first experiment the velocity, commencing with 100 
yards in nine seconds, was continually diminished to the foot of 
the plane, where it was reduced to 100 yards in 238 seconds, 
being at the rate of 12°6 feet per second, or 8°6 miles per hour. 
At this speed, therefore, with a favourable wind, the resistance of 
the carriage used in this experiment was greater than its gravity 
_ down 1 in 178. In the second experiment the speed, com- 

- mencing at 100 yards in eight seconds, was gradually retarded 
to the bottom of the plane, where it was reduced to 100 yards in 
sixteen seconds, or 12°75 feet per second, being at the rate of 

-12°8 miles per hour. Since the retardation had not ceased, the 
resistance of this carriage at the velocity of 18°8 miles per hour 
must be greater than its gravity down 1 in 178. In the fourth 
experiment, likewise, there is a continual retardation, com- 
mencing at 100 yards inseven seconds. The velocity was gra- 
dually diminished until, at the foot of the plane, it was reduced 
to 100 yards in 17°2 seconds, being at the rate of 17°44 feet per 

second, or 11°9 miles per hour, at which speed, therefore, the 
_ resistance of the carriage used in this experiment was greater 

_tlian its gravity down 1 in 178. In the third experiment the 
speed, commencing at 100 yards in seven seconds, was gradually 
reduced, about the middle of the plane, to 100 yards in 12°8 
seconds. Throughout the last 3000 yards the speed varied be- 

_ tween 100 yards in 11°8 seconds, and 100 yards in thirteen 
. seconds, alternately increasing and decreasing, probably from 
_ variations of the wind and the varying exposure on cuttings and 

embankments, accompanied probably with slight changes in the 

‘gradient. ‘The speed may therefore be regarded as practically 

uniform throughout this distance of 3000 yards, and its mean 
value was 100 yards in 12°7 seconds, or 23°62 feet per second, 
being at the rate of 16°6 miles per hour. 

__ The coach used for this third experiment was now taken to 
| the top of the plane and there dismissed with the speed of 100 
| yards in seven seconds, and it was determined to allow it to 
) me along the successive gradients until it should come to rest. 

_ To observe the motion, the gradients were staked out in intervals 

of 100 yards to a distance of 7200 yards beyond the foot of the 

plane falling 1 in 178. The seventy-second stake was 275 

yards short of the 534 mile post, and the line beyond that was 
divided by quarter-mile posts. The particulars of this experi- 
ment are given in the following table. 


VOL, VII. 1838, R 


246 EIGHTH REPORT—1838. 

| & a 

z : 9 - 2 : 
6} 96 Ylos|| 5 | s Lleol] g |e Lies 
es fale e|| 2 | os Balevl| S| os Elise 
B18 | vimeot |Sales||2 || timeot |SS/28| 2 | =| Timeor [SEES 
& |ig | Passing |GSlec||@ |i | Passing [Ggl.c||@ |i | Passing |ogice 
© | S| Stakes Le $=||S | 3] Stakes. [8 2 g=|| 6 S| Stakes. (2 g g§= 
mS} KH Sg | O Bsiskil 6 | O (=I be 
ale gFE/2|2 Bee al 2 |e g72 

ov o 
= = 
m s mis m s 

58 | 178 12 41 11 | 178 34 13 36 | 266 52 16 
57 | 178 48 i 10 | 178 46 12 /13°2|| 37 | 266 34 10 18 
56 | 178 55 7 9 | 178 FD 15 38 | 266 25 15 |16°2 
55 | 178 13 2 7 8 | 178 15 14 39 | 266 41 16 
54 | 178 10 8 71178 27 12 40 | 266 5 16 
53 | 178 17 7 6 | 178 41 14 41 | 266 35,13 16 
52 | 178 25 8 5 | 178 54 13 |13°6 || 42 | 266 28 15 
51 | 178 32 7 4 |178 23 9 15 43 | 266 43 15 |15°6 
50 | 178 40 8 | 7°6|| 3 | 178 23 14 44 | 266 59 16 
49 |178 49 9 2) 178 36 13 45 | 266 36 15 16 
48 | 178 59 10 1 |178 50 14 46 | 266 31 16 . 
47 |178 14 10 0 | 178 24 4 14/14 || 47 | 266 45 14 
46 | 178 18 9 1 | 266 19 15 48 | 266 14°6 
45 | 178 28 10 | 9°6|| 2 | 266 32 13 49 | 266 37 7 22 
44 | 178 39 ll 3 | 266 46 14 50 | 266 0 13 
43 | 178 49 10 4 | 266 25°32 16 51 | 266 38 18 
42 |178 15 1 12 5 | 266 17 15 52 | 266 53 15 
41 | 178 12 ll 6 | 266 23 16 53 | 266 38 8 15 |14°4 
40 | 178 23 11 11 7 | 266 49 16 54 | 330 23 15 
39 | 178 35 12 8 | 266 26 6 17 116 || 55 | 330 39 16 
38 | 178 46 ll 9 17 56 | 330 54 15 


ve 


The coach being dismissed from the summit with a velocity — 
of 100 yards in seven seconds, was gradually retarded until it 
reached the twentieth stake, when it attained a speed of 100 
yards in 134 seconds. It fluctuated between 100 yards in 13-2 _ 
seconds and fourteen seconds to the foot of the plane. The 
velocity, therefore, for the last 2000 yards may be considered — 

as uniform, its mean amount being 100 yards in 133 seconds, 
being the same with the result of the former experiment. At 
this speed, therefore, with a favourable wind, the resistance of . 


* Distance from this stake to 533 mile post = 275 yards. , 


RAILWAY CONSTANTS. 247 


the coach was equal to the gravity on the plane. As the coach 
descended the next gradient its motion was again gradually re- 
tarded until the speed became 100 yards in seventeen seconds, 
but was again accelerated until it became 100 yards in fourteen 
seconds, these fluctuations being probably due to the varying 
exposure to the wind. The uniform motion down this gradient 
may therefore, perhaps, be taken as a mean of the varying mo- 
tion of the train in descending it. This mean would be 100 
yards in sixteen seconds, or 12°8 miles per hour. 

If it be assumed that the train of four coaches used in the ex- 
periments down the Madeley plane, falling 1in178, had the same 
friction as the train of four first-class coaches used in the ex- 
periments down the Whiston plane (page 224), the proportion 

in which the whole resistance is in each case due to friction and 
the air, may be obtained by an easy calculation derived from 
the formule 26 and 27; making in these the following substi- 
tutions, 


m= ie 42, : 


peas pest e Pp ae ° 
og! = aap V = 49°45, Vi = 312, 
we shall find 


rf nh 
7 ~ 409° «17043 " 

In both these experiments the wind was favourable, but its 

- force unascertained, and in the formula from which these values 

i of f and a have been deduced no allowance has been made for 

its effect. By comparing the value of f thus obtained with the 

value of f in page 231, it will be seen that the present value is 

less in amount, as might be expected, from the effect of the wind. 

_ The resistance per ton due to friction according to this cal- 

culation would be 5°48 pounds, and the total resistance from 

| friction for the load of eighteen tons would therefore be 98°64 
pounds. 

Since the entire resistance of this load at twenty-one miles 
per hour was found by the experiments to be 226°8 pounds per 
| ton, it follows that the total resistance due to the atmosphere 
|was 128°16 pounds. 
| Two objections have been advanced against the method of 

determining the resistance by moving down inclined planes 
juntil a velocity be obtained which renders the resistance equal 
|to the gravitation on the plane. The first is, that the engine 
\not being in front of the train, the flat surface of the foremost 
\carriage is exposed to the air, and that a greater atmospheric 
‘|resistance is thereby produced than would be produced if the 
engine were in front of the carriage inasmuch as the engine 

R 2 


248 EIGHTH REPORT—1838. 


would hare, in a greater or less degree, the same effect upon the 
air as the bow of a ship has upon the water through which it 
is carried. 7 

The second is, that under such circumstances the moving 
power acts from behind against the resistance, in the same man- 
ner as an engine acts when used to push the train from behind 
instead of drawing it; that thereby the coaches composing: the 
train are thrown out of square, and the resistance from flange 
friction, and other causes consequent on such derangement, is 
increased, and is the main cause of the excessive amount of re- 
sistance which has been found in these experiments. 

To the first of these objections it may be answered, that the 
engine and tender placed in front of the train increase the 
amount of the transverse section by which the air is displaced 
in the motion of the train; the fire-box and ash-pit extend 
nearly to the ground, and fill a space which is left almost open 
in the absence of the engine; the chimney rises above the roof 
of the carriage and produces a resistance which has no existence 
in the absence of the engine; the head of the engine is usually 
flat, and so far as it is concerned produces as much resistance 
as an equal extent of flat surface upon the foremost end of 
the coach. The tender which follows the engine presents a 
concave form to the air, a form considerably more adapted to 
produce a resistance than the flat end of the carriage which it 
intercepts. 

Up to the period of writing this report no opportunity has 
been presented to the committee of ascertaining the force due 
to this objection by direct experiment; but it is intended to 
place an engine and tender in front of a train, disconnecting 
the working machinery,-so that the engine shall have no other 
resistance than a coach of equal weight and similar construction, 
and to repeat the experiment with the engine and tender so 

laced. It will then appear how far the resistance will be mo- 
dified by the form of the engine dividing the air in front. 

To the second objection it may be answered, that the case of 
the train moving by gravity down an inclined plane is not analo- 
gous to that of an engine pushing a train behind. In the latter 
case the whole power of the impelling force acts against the end 
of the last carriage, while the resistances which it has to overcome 
have their position in the moving parts of each individual car- 
riage, and in the frontage exposed to the resistance of the air. 
But in the case of a train descending an inclined plane by gravity 
neither the whole moving force nor any part of it acts against 
the back of the hindmost carriage: the moving force, being the 
gravitation of the matter composing the several carriages, will 


RAILWAY CONSTANTS. 249 


necessarily act at their respective centres of gravity. Thus the 
force which moves the first carriage will act at its centre, and 
that portion of it which is expended on the friction of that par- 
ticular carriage will act in a manner as favourable as a drawing 
force would act. The same may be said of the force of gravi- 
tation of the several carriages ; but that portion of the force of 
gravitation which balances the resistance of the air is subject in 
a modified sense to the objection. Thus, that part of the gra- 
‘vitation of the second coach which is over and above the resist- 
ance from friction, is transmitted to the first coach, and through 
it to the air which it drives before it; and the like may be said 
of the gravitation of each succeeding coach. But it should also 
be remembered that the resistance of the air to a train of coaches 
does not act exclusively on the front of the first coach. The 
| coaches of the train are nearly four feet asunder, and the air 
| probably acts more or less on the foremost end of each coach. 
_ This portion of the resistance is not acted upon with the same 
| disadvantage by the gravitation of the coaches as that resistance 
which is produced by the end of the first coach. 
_ It is intended to test the force of this objection by moving a 
train of coaches with an engine along a level, or up an inclina- 
_ tion, first placing the engine in front and afterwards behind, and 
| comparing the time taken by the engine to drive the train 
| agiven distance under both circumstances: but at the time of 
| making this report the committee had not had an opportunity 
_ of making such an experiment. 
_ Whatever importance may be attached to this objection, it is 
| presumed that it cannot fora moment be supposed that the dif- 
, ference between the resistance in pushing a train from behind 
| and drawing it in front can account for the enormous dispropor- 
__ tion between the common estimate of resistance, and that which 
| results from the experiments here given, the common estimate 
_ being about nine pounds per ton, while that which the trains 
| exhibited moved down the Whiston plane at thirty-two miles 
| an hour, amounted to more than twenty-three pounds a ton, 
_ and that even with the advantage of a favourable wind. 
| A further objection, however, has been made to the effect, 
| that the trains on which the various experiments have been 
“made, especially those with which the greatest velocities were 
attained, were lighter than trains generally are in railway prac- 
tice, and that therefore the proportion which the atmospheric 
“resistance would bear to the whole resistance would be greater 
than in practice it is, for that if the magnitude of the train were 
‘increased the resistance from the air would not be proportion- 
_ ately increased. 


250 EIGHTH REPORT—1838. 


Toa certain extent the force of this objection may be admitted. 
The fastest trains, however, on the Liverpool and Manchester 
railway, viz. the 11 o’clock first-class train consists invariably of 
four coaches and no more. The trains of passengers, however, 
generally consist of from seven to nine coaches, and it is in- 
tended before the next meeting of the Association to extend the 
experiments to trains of this magnitude. It will then be seen 
whether the lightness of the train increases the proportionate 
resistance at a given speed, and if so, to what extent. 

A summary of the results of the experiments contained in 
this Report is exhibited in the annexed table. It is, however, 
to be regretted that the effects of the wind were such as to 
render these results not so exact as could be wished. Still 
they may be regarded as tolerable approximations, all circum- 
stances considered. The experiments which appear to be en- 
titled to most attention and likely to give the most accurate re- 
sults, were those made with the train of four first-class coaches 
on the Whiston plane. 

In reviewing the results of these experiments, the near agree- 
ment of the several values obtained for the friction proper from 
different experiments by different principles and processes of 
calculation, is sufficiently striking, and affords a presumption 
of truth. Before, however, conclusions apparently so much in 
discordance with all previous estimates of resistance on railways 
can be accepted with confidence, it will be necessary to multiply 
and vary the experiments, and more especially to do so with a 
view to meet the objections which have been brought against 
some of those detailed in the present Report. Meanwhile, 
whatever be the source of the resistance to the tractive power, 
and whatever may be its exact amount, it does appear to be 
established by tolerably conclusive evidence that the resistance 
of railway trains at high speeds is considerably greater than the 
common estimate; and, on the other hand, that at low speeds 
it is probably less. Should it appear upon further investigation 
that the motive power necessary on railways has a material de- 
pendence on the speed, and that at high speeds, such as velo- 
cities from thirty to forty miles an hour, its amount is as con- 
siderable as the experiments here detailed would indicate, some 
important changes must be admitted in the principles which have 
hitherto guided those who have projected and constructed rail- 
ways. 

if it be admitted that the power engaged in opposing friction 
forms but a small part of the whole power used in working rail- 
ways at high speeds, it will become a matter of comparatively 
small importance to contrive means of diminishing an obstruc- 


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252 EIGHTH REPORT—1838. 


tion already of such trifling amount. The adoption, therefore, 
of large wheels, of expensive lubrication, of friction rollers, 
and of other similar contrivances for reducing the amount of | 
friction, will be clearly unadvisable, since such expedients would 
be attended with much more expense and inconvenience than 
would be adequate to any effects they could produce in dimi- 
nishing a resistance already so small. 

The importance of low gradients will be diminished. The 
advantages supposed to attend these are founded on the suppo- 
sition that the tractive power upon a level requires so great an 
increase when a moderate gradient is ascended, that either a 
superfluous moving power must be provided on the level, or that 
the moving power adapted to the level will be overstrained in 
ascending the gradient. So long as the resistance on a level is 
estimated at eight or nine pounds a ton, a gradient rising at the 
rate of eighteen or twenty feet a mile will require the power 
to be doubled ; but if the whole resistance on the level be con- 
siderably greater, and the proportion of it due to friction be small, 
then a much steeper inclination would be necessary to double 
the resistance to the tractive power; and, on the other hand, a 
small diminution in the velocity of the train would compensate 
for the increased effect from gravitation, In laying out lines of 
railway, therefore, intended exclusively or chiefly for rapid pas- 
senger-traffic, instead of obtaining by a large outlay of capital a 
road nearly level, steeper gradients would be adopted, and the 
resistance to the moving power rendered sufficiently uniform by 
variation of speed. That this has been in fact practically ac- 
complished on some of the more extensive railways now in 
operation in this country, is within the knowledge of some of 
the Members of this Committee; and it is hoped that in a 
subsequent Report they will be enabled to prove it by pro- 
ducing the actual results of such experience. 

If it shall appear, as now seems at least probable, that in 
railway traffic conducted at high speeds the chief part of the 
moving power is engrossed by the atmospheric resistance, it 
will be a matter for serious consideration how this resistance can 
be diminished ; and it is evident that, ceteris paribus, wide 
frontage, and therefore increased gauge is disadvantageous. 

These are points to the investigation of which the Committee 
will hereafter devote attention, and it is hoped they will be 
enabled to lay before the Association such experiments and such 
results of the practical traffic on railways, as will justify distinct 
and satisfactory conclusions upon them. 


ACTION OF WATER ON IRON. 253 


hirst Report upon Experiments, instituted at the request of 
the British Association, upon the Action of Sea and River 
Water, whether clear or foul, and at various temperatures, 
upon Cast and Wrought Iron. By Roserr MAu.cer, 
M.R.I.A. Ass. Ins. C.E. 


1. Tue subject of the present report, for the furtherance of 
which the Association, at its last meeting, made a grant of 
money, is one of great interest in a scientific point of view, and 
of paramount importance as an inquiry of civil engineering. 
Scarcely half a century has elapsed since the adaptation of iron 
in its various forms to the many purposes of the engineer, upon 
a scale before unknown, and as forming parts of public struc- 
tures whose limit of duration was to be measured, not by years, 
but by centuries, first made it necessary to inquire—What was 
the durability of the apparently hard and intractable material 
employed ? What were the forces likely to occasion its destruc- 
tion? How would they act? What would be their results? 
And what were the means of arresting their progress ? 

Yet important as a full answer to these inquiries would be, 
and though the application of iron in construction to harbours 
and ships, bridges and railways, and the innumerable other con- 
trivances by which the engineer subdues and administers the 
forces supplied by the Creator to the social wants of man, yct 
our information upon this fundamental subject is scarcely more 
advanced than it was twenty years ago; and while the chemist 
is not precisely informed as to the nature of the changes which 
air and water (our most universal elements), separate or toge- 
ther, produce on iron, the engineer is without data to determine 
what limit their corroding action sets to the duration of his as- 
piring and apparently unyielding structures. The investigation, 

therefore, is one full of importance to science and to the arts ; 
and although the commands of the British Association, as re- 

‘spects it, have not been neglected, yet the conditions of the 
subject were such, and the difficulties and delays in procuring 

_ the requisite specimens of iron so great, that the following re- 

port consists chiefly of a general survey of the present aspect 
of this field of knowledge, and of the operations commenced or 
intended by us for extending its boundaries, than of acquisi- 
tions already made. 

2. It comprises, therefore,—1st, a very brief “‘ précis”’ of the 
actual state cf chemical knowledge of the subject at large, viz. 


254 EIGHTH REPORT—1838. 


of the chemical actions, under various modifications, of air and 
water upon iron; 2nd, a statement of the experiments upon 
the large scale which have already been instituted at the re- 
quest of the British Association ; 3rd, a refutation of some fal- 
lacies as to supposed methods of protection of iron from the 
action of air and water; 4th, the suggestion of a proposed new 
method of protection of cast and wrought iron from these ac- 
tions, now in progress of experiment; and, lastly, the state- 
ment and consideration of such questions upon this subject as 
still stand in need of experimental answers, and are desiderata 
to chemical science and to civil engineering. 

3. There has been much discussion as to the number and 
composition of the oxides of iron, arising partly from the diffi- 
culty of procuring iron free from foreign matter for experiment, 
and partly from its oxides combining with each other. They 
are now reduced to two, viz. 


The Protoxide = FeO 

The Sesqui-oxide = Fe, O;. ~ 
The hydrate of the first is not permanent, and its water has not 
been precisely determined ; it is highly probable from analogy 
that it has the composition FeO + 2HO. . 

There are two hydrates of the sesqui-oxide, one of which 
occurs native = 2 Fe,O, + 3H O, and the other formed arti- 
ficially = Fe,O; + 3 HO, and others probably exist. These 
two oxides are capable of combining and forming 

Magnetic oxide (native) = Fe,O, + FeO, 

Forge scales (battitures) = Fe,O; + 6FeO, 
Other less distinctly ascertained combinations have been de- 
scribed. It is dubious whether forge scales are a chemical com- 
bination at all, but rather a mixture of the protoxide and sesqui- 
oxide in progress of change by cementation into the latter. 

4, And first of our chemical knowledge of the action of air 
and water upon iron. 


Of the Action of Pure Water upon Iron. 


‘* Pure water deprived of air does not act on iron at any tem- 
perature below 80° Reaum.=212° Fahr., and at that but slowly. 
The water was freed from any air by Hall, by boiling, and by 
the action of the iron itself.””—(Marshall Hall, Phil. Trans. 
1818; Karsten, Chim. du Fer.) 

‘At ared heat, and above it, iron is instantly oxidized by 
decomposition of vapour of water, producing, according to Ro- 
biquet and others, (Fe,O, + FeQO).’?—(Journal de Pharm. 
1818.) 


ACTION OF WATER ON IRON. 255 


The resulting combination, the oxidum, ferroso-ferrique of 
Berzelius, is, according to him, by long continued watering, 
converted all into a hydrated peroxide (Fe,.O; + 2HO). Gay 
Lussac, however, states, that it is impossible to oxidate iron to 
its maximum by the action of water, which seems most proba- 
ble. He states the composition of the oxide produced at 37°8 
per cent. of oxygen, which approaches that of the native mag- 
netic oxide. Neither iron nor its oxides are at all soluble in 
pure water according to Westrumb. 


Of the Action of Dry Air upon Iron. 


5. Perfectly dry air has no action whatever on iron, nor has 
dry oxygen below ignition, unless we consider the ‘‘ blueing ”’ 
of steel as a state of oxidation. Both air and oxygen rapidly 
decompose iron at and above the temperature of ignition, pro- 
ducing, according to Berthier, sesqui-oxide of iron, quadri-pro- 
toxidated = Fe,O; + 4FeO. : 

Mosander’s results, however, do not agree with these; he 
found, that iron oxidated by dry air, at a red heat, produced an 
outer coat of sesqui- or peroxide, and beneath this, one having 
the composition (F e,O; + 6 FeO). 

The extreme slowness with which moderately dry air acts on 


| iron is evidenced by an experiment of M. Zumstein, who fixed 


a polished iron cross on the summit of Monte Rosa, in the Alps, 
in August in 1820: on visiting it again, in August, 1821, it 
was found neither rusted nor corroded, but had merely acquired 
a tarnish the colour of bronze. The temperature of the air was 
21° Fahr. Barometer, 16 inches 42 lines, and height above the 
level of the sea, 14,086 feet.—(Bib, Univer. xxxiii. p. 65.) 


6. Of the Action of dir and Water combined on Iron. 


_ While at common temperatures, both air and water are sepa- 
rately strictly neutral bodies in respect of iron ; yet when acting 
_ conjointly, the case is widely different. In general it may be 
stated that any neutral body, however slight its own electro- 

positive or negative relations may be in presence of iron and 
oxygen, will modify the action of these bodies on each other 

in proportion as it tends to render the oxygen more negative 
and the metal more positive. 

7. It must be confessed that there are many points in the ac-. 
tion ef air and water combined still in need of being experi- 
mentally cleared up. We are enabled, however, to discern the 
general nature of the phenomena. We are to be understood as 
speaking, in the first instance, of wrought and malleable iron, 


256 EIGHTH REPORT—1838, 


or iron as nearly pure as possible. Air or oxygen dissolved in 
water is in a condensed state, and hence in a condition pecu- 
liarly appropriate to combination. Rain water frequently con- 
tains, when fresh fallen, one-fifth of its volume of oxygen. 

8. When a piece of iron is immersed in such water, the whole 
becomes electrically excited. The water, rendered more nega- 
tive by contact with the iron, repels its dissolved oxygen, while 
the iron, become more positive by the contact of water, exer- 
cises an unusual affinity for the oxygen. Supposing the surface 
of the metal everywhere uniform, a film of oxide is soon pro- 
duced over it, and this once effected, decomposition proceeds 
with increased rapidity ; for as every metal is positive with re- 
gard to its own oxides, it follows that the film of rust and the 
iron beneath now form a voltaic couple of greater energy than 
the last; and whereas the electric energies were before only 
sufficient to bring the dissolved oxygen of the water into com- 
bination with the iron, they now become sufficient to decompose 
the water itself, and hydrogen commences to be evolved. At this 
epoch, if the volume of water be not too great in proportion to 
the iron, and the latter present a large surface, as in the pre- 
paration of Aithiop’s Martial, considerable heat even is evolved, 
but the water is previously decomposed in the cold. (Guibourt, 
Jour. de Pharm. 1818.) It is a most remarkable fact, how- 
ever, that while iron has this vigorous action on water holding 
air in solution, neither the metal nor its peroxide have any on 
the eau oxygené of Thénard.—(Thénard, Traité.) 

9. Should the surface of the iron not be uniform in the first 
instance, as when patches of rust pre-exist upon it, or when 
one part is much harder or denser than another, these form 
voltaic elements from the beginning and aid the progress of 
oxidation. In nearly all specimens of wrought iron, when ex- 
posed to the action of water holding air in solution, in addition 
to the first coat of rust, one of carbon and sometimes, in mi- 
nute quantity, of oxides higher in the electro-negative scale, are 
deposited upon its surface, which still further exalt the condi- 
tions favouring corrosion. 

10. When iron is freely exposed to air and water in a shallow 
vessel, the result of their reaction is a hydrated peroxide; if, 
however, the surfaces of the iron are placed near, but not in 
contact with neutral solids, as glass or porcelain, or the depth 
of water be considerable, there is also formed a large proportion 
of magnetic oxide. Becquerel considers this difference to be 
owing to the increased slowness of action in the latter case, 
from the greater depth to which the water has to carry the 
oxygen. 


| 
gy 
i 
: 
y 
4 


ACTION OF WATER ON IRON. 257. 


11. It has been doubted by Marshall Hall and others, who 
assert that nothing but nitrogen is evolved, whether water is 
ever decomposed by iron at common temperatures, though in 
presence of air; but independent of the conclusive and simple 
experiment of Guibourt, of mixing in large bulk iron turnings 
and water, and collecting the hydrogen, Becquerel is of opi- 
nion, that the existence of ammonia in the oxides produced, 
which was first detected by Vauquelin, is corroborative of the fact, 
inasmuch asthe water must suffer decomposition as well as the 
air, in order that the hydrogen and nitrogen may combine to 
form ammonia. Chevallier and Bousingault also found ammonia 
in the native oxides of iron ; and Austin states, that it is always 
present when iron is oxidated by air and water. (Ann. de Chim. 
vol. xxxiv. p. 109.) ‘Too much stress, however, cannot be laid 
upon this argument, as it has been found that rust, in common 
with other porous bodies, greedily absorbs ammonia and many 
other gaseous substances. 

12. When the action of air and water on iron has taken place 
with sufficient slowness, the resulting oxides are found crystal- 
lized in the form of the native octohedral iron ore. Becquerel 
describes a case of crystals, of both hydrated and anhydrous 
peroxides, found united in one specimen of corroded wrought 
iron from an old chateau of the ninth century. The hydrated 
oxide would seem here to have been formed first, and after- 
wards decomposed by the action of the still unchanged iron 
upon its water. 

13. When water contains foreign admixture, the composition 
of the rust resulting from its action varies accordingly, together 
with the rapidity of its corrosion; thus, when it contains car- 
bonic acid, the rust contains water and subcarbonate of iron, 
according to Dr. Thomson; and Soubeiran found rust under 
such circumstances, formed of the sesquioxide, combined 
with 3 atoms of water, and containing variable quantities of the 
sesqui-basic carbonate of iron, and occasionally the carbonate of 
the protoxide. Carbon is always, silica occasionally, deposited 
from the iron dissolved. 

14. With the exception of those bodies which are occasionally 


-met with in mineralized waters, and of carbonic acid, and the 


constituents of sea water, that rendered foul by decaying organic 

matter, and that from mines, all others are rather beside our 

present object, as modifying the action of air and water on iron. 
We proceed, then, to consider the nature and results 


Of the Action of Sea Water on Iron 
at ordinary temperatures; and although the results of the careful 


258 EIGHTH REPORT—1838. 


observations of Marcet, Scoresby, and others, show that the water 
of the ocean is rather denser , or contains more saline matter in 
torrid and temperate zones than in high latitudes, yet from 34 
to 4 per cent. of solid salts may be taken as the general average. 
And as these have a complex constitution, so the results of their 
action on iron and water containing air are complex; and expe- 
riments are yet wanting to enable a perfect rationale of the pro- 
cess to be given and its results precisely stated. 

15. In the first instance the actions already described, in the 
case of air and pure water at low temperatures, take place and 
give rise to the oxides of iron; and as the sea water almost 
always contains carbonic acid, a portion of these is resolved into 
carbonate of iron. 

16, As in pure so in sea water, when iron is deeply immersed 
the oxide produced is the magnetic in the first instance, the 
iron becomes covered with a light buff coat of rust; but if the 
vessel be shallow, the sesqui-oxide is formed gradually from it. 
In each case, the first appearance of action which the fluid pre- 
sents is the formation of numerous slight green streaks in it. 
These form usually in about thirty minutes from immersion of 
the metal, and appear to be protoxide in progress of transition 
into magnetic oxide and sesqui-oxide, of which latter oxides a 
large precipitate soon forms at the bottom of the vessel. 

17. But as sea water likewise contains chlorides of sodium 
and magnesium, the carbonate of iron is, in part at least, de- 
composed, and a subchloride of iron is formed which unites 
with a part of the sesqui-oxide of iron, having previously as- 
sumed the state of sesquichloride, and forms with it an inso- 
luble compound. 

18. It happens hence, after a mass of iron has lain for a con- 
siderable time in a limited quantity of sea water, that the latter 
holds carbonate of soda in solution, and the further action be- 
comes very slow, and that a hydrated carbonate of magnesia 
has deposited on the iron. 

19. It would appear also, that the sulphates are in part de- 
composed, the sulphuric acid passing to the iron and forming 
a basic insoluble sulphate, and the lime an insoluble carbonate, 
with the carbonic acid of the water. But sulphuric acid is by 
no means wniformly to be detected in the ochreous deposit 
formed by the action of sea water on iron, nor indeed chlorine 
either. But besides chlorides, sea water contains bromides and 
iodides, and of the part which these play in the decompositions 
consequent on the action of iron, it must be confessed we are as 
yet wholly ignorant. Analogy, however, gives reason to pre- 
sume they play similar parts to the chlorides. 


ACTION OF WATER ON IRON. 259 


20. If malleable iron or steel have been subjected to the sol- 
vency of sea water, carbon and sometimes silicon are deposited 
in small quantities ; but when cast iron is acted on more re- 
markable results follow. After it has remained for a length of 
time immersed, the metal is found wholly removed, and in its 
place a pseudomorph of its original size remains, as first observed 
by Priestley, consisting of a carbonaceous substance, analogous 
to plumbago, mixed with oxides of iron, and which frequently, 
but not invariably, possesses the property of heating or in- 
flaming spontaneously when exposed to air. There have been 
unfortunately, as yet, but few cases of this remarkable change, 
which requires the lapse of time to take place, carefully ob- 
served; and it is as yet by no means clear how it is produced, 
what is its precise composition, or to what is owing the rise in 
its temperature on exposure to air. 

21. It is remarkable, that not cast iron alone is subject to 
this change ; under circumstances but little understood as yet, 
the purest malleable iron is alike converted into what we shall 
for brevity call plumbago. 

Karsten mentions, that when iron, whether wrought or cast, 
has been long exposed to water holding in solution alkaline or 
earthy salts, it is at length dissolved ; that when hard bar iron 
had remained some centuries in sea water it was altogether dis- 
solved, and a mass of carbonaceous matter remained, as though 
it had been submitted to the prolonged action of a diluted acid. 
This change, he says, is generally attributed to the decomposi- 
tion of the carbonic acid contained in the sea water; but it is 
much more likely that, in the long run, the sulphates and chlo- 
rides contained in the sea water are decomposed likewise by 
the iron. 

The writer possesses a portion of an ancient anchor taken up 
in the port of Liverpool, the iron that remained of which was 
of remarkable purity, and which was converted into plumbago 
of unusual hardness and brilliancy to the depth of half an inch. 
This plumbago did not heat on exposure. Its specific gravity is 
1°773. This fact militates against an observation made by Hatchet, 
and repeated by Becquerel, that anchors and other objects of 
forged iron sustain no alteration in sea water but oxidation, 
from which we must suppose that the contact of iron and plum- 
bago in the cast iron produces a voltaic current, which accele- 
rates the action of the latter. 

Berzelius’ opinion is, that the carbonic acid contained in the 
water dissolves and removes the iron. He quotes an instance 
of the guns of a vessel which had foundered off Carlscrona, 
which, when taken up fifty years afterwards, were found nearly 


260 EIGHTH REPORT—1838. 


wholly converted into plumbago, and which heated to such an 
extent in a quarter of an hour after exposure as to evaporate the 
water contained in its pores. He adds, “ We know not pre- 
cisely what passes under these circumstances.’’—(Traité de 
Chim. vol. iii.) Dr. M‘Calloch states, that plumbago thus 
formed always possesses the property of spontaneous heating. 
This, however, from the writer’s own observation, is certainly 
erroneous.—(Edin. Phil. Jour. No. 14.) 

Hatchet examined a specimen of plumbago which remained 
long immersed in sea water at Plymouth: he found it contained 
a little chloride of iron, and that it was composed of 


Oxide of iron. . 0°81 
Plumbago . . . O16 
0°97 

Dr. M‘Culloch made several experiments upon the artificial 
formation of this plumbago by the action of diluted acids ; he 
found it bore in quantity no definite relation to the species of 
cast iron from which it was obtained. 

Pig iron produced more than that cast into guns or shot; of 
the latter the blackest varieties, as might be expected, produced 
the most. 

This author mentions a case of its production from the action 
of London porter on iron, and also of the recovering of some of 
the iron guns of the Armada off the coast of Mull, which be- 
came so hot on being weighed, that they could not be touched. 
He found that the produce of plumbago from the blackest cast 
iron, dissolved in dilute acetic acid, equalled the bulk of the 
iron, and was not pulverulent, but coherent, so as to be cut 
with a knife. 

In some cases the plumbago heated, and in some it did not; 
in the latter he presumes oxygenation to have taken place du- 
ring solution. 

From his experiments Dr. M‘Culloch drew the rather singu- 
lar conclusion, that the plumbago was the oxide of a peculiar 
metal, the oxygenation of which produced the heating. 

Dr. Thompson, in commenting upon this paper, observes, 
that M‘Culloch appears ignorant of the existence of silicon in 
cast iron, and of Daniell’s experiments upon the subject. 

22. Mr. Daniell has given some interesting experiments on 
this subject in a paper, on the structure of iron developed by 
solution, in the Journal of the Royal Institution. In this, after 
describing the formation of this plumbago by the action of di- 
lute acids, and its properties, he gives an analysis of the sub- 


To. 
’ 


ACTION OF WATER ON IRON. 261 


stance, and a theory of the cause of its heating on exposure 
to air. 

Hydrochloric and sulphuric acids both produced it. Nitric 
acid produced it, but in a state incapable of heating in air. It 
did not lose this property by long exposure in a solution of a 
salt of iron, or in water. It absorbed oxygen from the air with 
evolution of heat. In pure oxygen or chlorine it became much 
hotter, absorbing either: the residue, after absorption of oxy- 
gen, was found to contain silex; and Mr. Daniell considers 
that the plumbaginous compound consists of carburet of iron 
and silicon, and that, by absorption of oxygen, these became 


_ protoxides without separation from the carbon. 


q 
‘a 
‘ 


The experiments of Berzelius and Strémeyer, however, ad- 
duced by Mr. Daniell in support of this view, appear rather to 
militate against its truth; and however it may be a “ vera 
causa’ that the presence of silicon may occasionally produce 
the spontaneous heating of this plumbago, the result of my 
own experiments prove that it can be produced from many 
specimens of cast iron which do not contain a particle of si- 
licon. 

23. Dr. William Henry has given, in Thomson’s Annals for 
January 1815, an interesting account of his examination of this 
substance produced from cast iron in a coal-pit shaft near New- 
castle-on-Tyne. The cast iron was part of a pipe used to con- 
vey the water, and evolved gases from a bed of quick sand; its 
external characters were the same as those previously described. 
The specific gravity of the specimen was from 2°008 to 2°155. 
He states its composition “as iron, plumbago, and the other 
impurities usually present in cast iron ;’’ his examination, how- 
ever, was cursory and rather imperfect. The water from the 
shaft contained 64 grains in a wine-pint of chlorides of sodium, 
calcium, and magnesium, and of the sulphate and carbonate of 
lime. He ascribes the removal of the metal to decomposition 
of the chlorides, and instances their capability of removing the 
iron from ink. He also adds a case of conversion of cast iron 
into plumbago by the action of steam and powdered charcoal 
on it. 

24. Dr. Thomson gives in his Annals for 1817 a case of like 
change, produced, with unusual rapidity, by the action of sour 
paste, or weavers’ “dressing” to cast-iron rollers. The change 
was so rapid as to oblige the substitution of wood for iron. It 
is not stated whether the rollers were heated by steam or 
otherwise, or were at the atmospheric temperature. In the 
Annals for 1825, a very interesting case is.given in a letter 

VOL. vil, 1838. S 


262 . EIGHTH REPORT—1838. 


from Charles Horsfall, Esq. to Dr. Traill, in which bars of cast 
iron of 3 inches broad by 1 inch thick, which formed protectors 
to the copper of a vessel, to the amount of about +3, of its sur- 
face, were, in a voyage of not quite five months, to Jamaica and 
back, converted into plumbago to the depth of half an inch; it 
heated on being scraped and exposed to the air when the ship 
first went into dock. Mr. Brande, in the Quarterly Journal, 


vol. xii., describes an iron gun which had long lain in water as ~ 


conyerted into plumbago to the depth of aninch. I have also 
been favoured by my friend, Mr. Firmston of Glasgow, with a 
piece of similarly changed cast iron from the false keel of the 
John Bull, East Indiaman. In four years this piece of 1} inch 
by 4 inches was completely altered through. Its specific gra- 
vity is 1°259. I have not yet been enabled to determine the 
composition of this specimen, or that from the wrought iron 
before alluded to. 

25. Mr. Pepys found cast iron similarly changed by the ac- 
tion of pyroligneous acid (Gill’s Zech. Rep., vol. ili.); and I 
have myself obtained specimens so produced by this acid in a 
state of vapour. The same change is produced by the vapour 
disengaged in the roasting of coffee ; and a curious case of simi- 
lar action of sherry wine on wrought iron and steel is to be 
found in Thomson’s Annals. It is also well known that the 
cast-iron plates at first used in the interior of Coffey’s Patent 
Still, were rapidly converted into plumbago by the action of 
the low wines and proof spirits, Much more lately cannon 
shot have been found immersed in the sea, near the site of the 
battle of La Hogue, converted to the depth of an inch into plum- 
bago, or, according to another statement, all through. The 
battle of La Hogue took place in May 1692; henee these shots 
have lain in the sea for a period of about 145 years; it is pro- 
bable they were thirty-two pound shot, and, if converted into 
plumbago ail through, this fact shows that some cast irons may 
be wholly destroyed in the above period by sea water, to the 
depth of 3} inches,—a 32 1b. shot being about 67 in. in diameter. 

26. [have thus collected and given at a tedious length nearly 
all the cases of this singular change published ; they serve as an 
index for future experiments, and they show how very little we 
know of the real nature of the phenomena. It is equally ob- 
vious that, from the want of precision and of data as to time 
and surface, &c. in most of the statements, no information is 
afforded of any use to the engineer. 

It strikes one at once, that every author hitherto who has 
studied this subject has wholly omitted any consideration of a 


te se, 


se 


ACTION OF WATER ON IRON. 263 


most important result which the carbon in iron, especially cast 
iron, plays during its solution. 

It is established that carbon exists in cast iron, steel, &c. 
in two states: as graphite or crystallized carbon, disseminated 
in its mass, giving it brilliancy of fracture, softness, porosity, 
and fluidity in fusion ; and as a definite carburet, combined with 
a portion of the iron chemically, and mixed mechanically with 
the remainder. 

Now, in the decomposition of iron so circumstanced by air 
and water, whether in presence of an acid or not, besides the 
combination of oxygen furnished both by the air and water with 
the metal, other reactions take place. Nitrogen and hydrogen 
are both set free, but they may or may not be both evolved. The 
nitrogen combines with part of the hydrogen to form ammonia, 
which, according to circumstances, is evolved, or combines with 
the oxides of iron produced. 

But it is probable, from the experiments of Thénard and 
Despretz, that an azoturet of the undissolved metal may also be 
formed. Iron at a higher temperature is unquestionably capable 
of decomposing ammonia and combining with azote, so as to aug- 
ment its weight by 0°12. But in addition, as the combined car- 
bon is set free from the iron in a nascent state, it seizes upon 
a portion of the evolved hydrogen, and forms a highly volatile 
and odorous oily hydrocarbon, while some of the uncombined 
or suspended graphite, also set free in a highly divided state, 
combines with another portion of the hydrogen and with oxy- 
gen, and produces an extractive matter—apothéme of Berzelius, 
and which differs little from ulmic acid in its reactions. This 
latter deposits as a brown substance, soluble in alkalis, &c., 
and combined with all the magnesia and silica due to the 
amount of their bases, which the iron may have contained, if 
any. The volatile oily hydrocarbon is partly dissipated with the 
hydrogen evolved, partly swims upon the surface of the fluid, 
rendering it irridescent, and is partly held absorbed by the 
porous mass of oxides, carbon, and ulmic acid resulting from 
the whole reaction. Hence we see that the simple decomposi- 
tion of cast iron by air and water may give rise to no less com- 
plex a result than the following formula indicates :— 


(FeC,+C + S,i + Mg) + (HO + N,O) =(Fe,0,+ FeO) 
+ (Fe,0,+3HO) + (H+C,-Hy.) + (CoH5o0,5? + S10, + MgO) 
+ 


And here several of the substances commonly present in cast 
iron are omitted; if these be included, or an acid present, the 
result will of course be still further complicated. 

s2 


264 EIGHTH REPORT—] 838, 


27. Now to the presence of these hydrocarbons I conceive we 
are to look for the phenomenon of the spontaneous heating of 
the plumbaginous matter, so many cases of the production of 
which have been adduced. It appears to be owing to their fur- 
ther oxidation, on exposure to air, presenting a great surface to 
absorption as existing in the porous mass of plumbago, and to 
be a strict analogue of the cases of spontaneous combustiomw 
produced by various fat oils, &c. exposed to air, in contact with 
cotton, linen, &c. &c., or other carbonaceous bodies exposing 
a large surface to absorption. The fact that cast iron, which 
will produce spontaneously-heating plumbago, when decomposed 
by air and water, or by hydrochloric acid, when dissolved in 
nitric acid, gives a plumbago which will zo¢ heat spontaneously, 
favours this view of the subject; the nitric acid supplying the 
oxygen in the first instance. 

This is at present but an hypothesis used in directing experi- 
ments now in progress to determine the ultimate constitution of 
these hydrocarbonous compounds, which have not yet been ana- 
lyzed, or collected even in sufficient quantity to admit of ana- 
lysis by others, and to discover the nature of the changes which 
they suffer in:presence of air or oxygen. 

28. The analogy of this substance with the carburets pro- 
duced by the destructive distillation of the iron salts of the or- 
ganic oxacids and cyanogene compounds, is obvious. These, 
Berzelius is of opinion, are true carburets, while other chemists 
conclude them to be mere mixtures of finely-divided carbon 
with the base of the salt. 

I cannot, however, but coincide in the view of Boncharlat, 
whose experiments lead him to believe them mixtures of car- 
bon, with one or more definite carburets of iron whose pro- 
perties he has described. If thus, they are analogous to the 
conditions in which carbon exists in cast iron itself. 

29. It also bears a striking resemblance to the powders de- 
scribed by Messrs. Stodart and Faraday, as obtained by the so- 
lution of some of their alloys of steel in sulphuric and hydro- 
chloric acids : these were not acted on by water, but oxidated in 
air, and burnt like pyrophorus when heated to 300° or 400° 
Fahr., leaving protoxide of iron and the alloying metal. They 
conclude, that during the action of the acid, hydrogen entered 
into combination with the metal and charcoal, and formed an 
inflammable compound, as they found these powders sometimes 
burnt with flame. By the action of nitric acid on these powders 
they obtained some fulminating compounds. 

I have found that when borate of lead is decomposed by the 
joint action of charcoal and platina with heat, a boruret of pla- 


ACTION OF WATER ON IRON. 265 


tina is formed, which, on subsequent digestion in nitric acid, 
becomes powerfully explosive; boron here apparently playing 
the part of the carbon in Mr. Faraday’s compounds. 

30. The inflammable powders produced by Magnus, by reduc- 
tion of the difficultly fusible metals by hydrogen, also connect 
themselves with the subject. To complete our knowledge of all 
these remarkable substances, with reference to the immediate 
subject of this report, will need a careful and extensive series of 
experiments. 

31. There have been but few observations made as to the 
variations in composition of cast and wrought iron as regards 
their acceleration or retardation of the action of solvent agents 
upon it. It is not known at this moment with certainty what 
properties should be chosen, in either cast or wrought iron, 
that its corrosion may be the least possible, under given cir- 
cumstances, when used in construction. 

32. Faraday found the alloys of most of the metals he tried 
with steel much less acted on by moist air than steel unalloyed; 
but he also discovered the remarkable circumstance, that a very 
minute quantity of an alloying metal produced an increased ac- 
tion of sulphuric acid on steel, within certain limits; thus, z1, 
of platina greatly increased the action of the acid on the steel 
with which it was alloyed ; with from 735 to 4,5 it was power- 
ful; with 10 per cent. of platina there was a feeble action ; 
with 50 per cent. of platina the action was the same as with 
unalloyed steel; and an alloy of 90 platina and 20 steel was not 
touched by the acid. In these cases even acids of very weak 
combining power, as oxalic, tartaric, and acetic, rapidly dis- 
solved the steel. Of three possible modes of accounting for 
this suggested by Sir H. Davy, Mr. Faraday justly chooses 
that which supposes the platina in part forming a definite alloy, 
and the remainder diffused through the substance of the steel ; 
thus forming an indefinite number of voltaic elements. On the 
first action of the acid some of the particles of platina are de- 
nuded, and being strongly negative with respect to the rest of 
_ the compound, aid its solution. Upon this ground the action of 
the excess of platina, in reducing the action, is obviously de- 
pendent upon the whole alloy becoming definite again. Solu- 
tions of chloride of sodium did not act more rapidly on these 
alloys than on steel alone. 

33. It has been long observed how little liable to tarnish or 
rust native and meteoric iron are, which contain often as much 
as 9°5 per cent. of nickel, and variable proportions of chrome 
and cobalt. The following tables embody perhaps the whole of 


266 EIGHTH REPORT—1838. 


our present knowledge on this interesting point, in which the 
alloying metals are grouped according to their producing an 
alloy more or less corrodible by oxidizing dgents than iron 
alone. 


Alloys more Cor- ae Alloys less Corrodible me 
rodible than Iron. Authorities. than Iron. Authorities. 
Potassium.... | Serullas Nickel ........ | Berzelius 
Sodium. 3.0.4: <i Cobalt ean cank PA 
Barium...... | Lampadius fi re ee re eae Rinmann 
Glucinum.... | Davy Copper i-inr Karsten 
Aluminum ... ) Copper and Zinc | Vazie 
Manganese... | Berthier Mercury....... | Berzelius 
Silver ..... Berzelius TOTO execu Karsten 
Pltaia. 2. ee Faraday smitinie swe Fy 
Silicium ©. -: Berthier Columbium .... | Berthier 
Antimony.... | Serullas Chfoniel. Por 
Arsenic...... Berthier 3 


The metals are here arranged according to their electrical 
order, beginning with the most positive. In the first column 
all above silver are positive to iron, and all below it, inclusive, 
and in the second column, negative to it. It is obvious, how- 
ever, that this gives us very defective information, as Faraday’s 
case of the platina alloy shows that mere difference in propor- 
tion may wholly change the properties of the alloy in this re- 
spect. An analogue to the peculiar action of the platina in this 
case is found in the epigene crystals of native oxide of iron, 
which are generally auriferous, and have the form of the bisul- 
phuret of iron, whose.decomposition the electric agency of the 
noble metal seems to have facilitated, though present in such 
minute quantity in an uncombined state. 

34. Dr. Faraday also found that the alloys of pure iron were 
less acted on by moist air than those of steel. It is also ex- 
ceedingly remarkable, that in respect of corrodibility, the alloys 
of steel follow a totally different order to those of wrought iron. 
In the following table the first column shows the order of cor- 
rodibility of various alloys with steel, compared with steel alone, 
commencing with the less corrodible ; and the second column 
shows the electric order of the metals with reference to iron, 
beginning with the most positive. 


———”- - —_— = 


ACTION OF WATER ON IRON. 267 


ee ee a el ee 
ORDER oF CorropiBiLiTy.| ELecrric Orper. E-4. 


Unalloyed Steel. Iron or Steel. 

Steel and Chrome Nickel 
Silver Silver 
Gold Palladium 
Nickel Platina 
Rhodium Rhodium 
Tridium Iridium 
Osmium Gold 
Palladium Osmium 
Platina Chrome 

Hix 


It is obvious that each of these must be considered, not as a 
binary alloy, but as a ternary compound of two metals with 
carbon, or of one metal with a carburet of iron. These tables 
point out a wide field for experiment of great interest. 

We may from these results conclude, that the alloy of iron 
with any metal in a negative relation to it, unless the alloy be 
definite, will probably be attended with an increased corrosion 
of the metal; and that its alloy with a metal positive to it, though 
it may possibly initially protect the iron from action, will, by 
its own removal, be likely to render its texture open and porous, 
and hence more fitted for subsequent solution and removal. 

35. M. Vazie has recommended an alloy of brass and cast 
iron, in other words, a quadruple compound of carbon, copper, 
iron, and zinc, as a suitable metal for various large works where 
capability of resisting rusting or corrosion is important. It is 
stated that experiments made with it on a large scale, at Glei- 
witz, in Silesia, were attended with satisfactory results. These 
require repetition, and much may possibly yet be done in im- 
proving the durability of cast iron by minutely alloying it. It 
will be recollected, that a minute quantity of iridium alloyed 
with iron confers on it the same power of being hardened by 
rapid cooling that carbon, boron, and silicon do. 

36. The porousness of the crystalline grain of cast iron is 
frequently very remarkable, and is such as to permit many fluids 
to enter its pores, and actually saturate the metal like a sponge. 
A very remarkable case of this is recorded in the Quarterly 
Journal of Science, vol. ii. p. 385. M. Clement formed a 
large cylinder of copper, within which he placed a turned cylin- 
der of cast-iron, also bored out; a space intervened between 
the two, into which he poured melted tin. To his surprise, on 
becoming cold, much of the tin was squeezed through the cast- 
iron cylinder, and appeared as a fine filamentous wool, lining 


268 EIGHTH REPORT—1838. 


the internal part of the cast-iron cylinder. It was of such 
tenuity as to take fire and burn at a candle like tinder. It is 
here obvious that the iron and copper cylinders were heated 
alike, but the latter expanded much more than the former, and 
hence, on cooling, compressed the tin (still fluid, probably, about 
the centre of the length of the cylinder, although cold at its 
ends), and forced it out through the pores of the iron. The 
limit of force here was only that of the cohesion of the copper 
cylinder. 

37. It is usually considered an ignorant prejudice of workmen, 
that a “ hard skin,”’ as it is technically called, is given to cast 
iron, after planing or turning, by coating it with oil, and, until 
a short time since, I was myself of that opinion; but, on exa- 
mining some broken castings, whose surfaces had been turned 
and exposed to oil for several years, I found that the oil had 
penetrated the pores of the iron to a considerable depth. 

38. I also possess a piece of cast iron, of considerable thick- 
ness, which formed, I believe, part of a furnace for decomposi- 
tion of sea salt; it contains throughout its mass a minute 
quantity of chloride of sodium, and a great deal of sulphur. 
This has been produced by cementation, in the same way as 
Herapath describes an alloy of 


Aine’... +. i 92°6 
Tron’ fcr. 74 L060 


as being produced in the Bristol Zinc Works ; and as alloys of 
cast iron with arsenic, antimony, and lead have been formed. 
These observations are intended to show the importance of se- 
lecting close-grained cast irons for works designed to resist 
longest the action of air and water. 

39. Of the relative rates of corrosion of the various com- 
mercial ‘‘makes,’’ or specimens of wrought and cast iron, 
scarcely anything is known, and that of a very general cha- 
racter. It is certain that the blackest cast irons, viz. those 
which contain the largest quantity of uncombined carbon or 
graphite in a mere state of mixture, are acted on by air and 
water the most rapidly. This has probably partly an electro- 
chemical cause, and partly a mechanical one, from defects of 
hardness, and open and porous grain. There can be little doubt 
but that the suspended graphite in this kind of iron forms the 
negative element of innumerable voltaic couples which aid the 
process of oxidation. 

The gray or mottled iron most used for castings of ma- 
chinery and engineering purposes in general, as containing a 
less quantity of uncombined carbon, and haying a denser 


——- <— # 


ACTION OF WATER ON IRON. 269 


structure, is less acted upon; and the varieties of iron which 
present scarcely any symptoms of a crystalline texture at all, 
but still are grained or mottled, and can barely be touched by 
the file, turned, or bored, are those which, while they are still 
capable of being used for almost every purpose to which cast 
iron is applicable, are the least susceptible of alteration or decay. 

40. The officers of the French artillery, amongst whom M. 
Born has been most conspicuous, have made a number of expe- 
riments on this branch of our subject. They have found that 
the corrosion of iron by air and water is greater in proportion 
to the purity or goodness of the coke with which the iron is 
made, and that it is altered less when made with charcoal than 
with coke. In the former case, it is probable this arises from 
the iron containing the largest dose of uncombined carbon or 
graphite ; and in the latter, namely, in that made with charcoal, 
it seems to arise from the less quantity of silicium contained in 
this cast iron. Various careful analyses made by Berzelius, 
Karsten, Berthier, and others, show that, while coke-made iron 
contains from 0°025 to 0:045 of silicium, that made with char- 
coal only contains from 0°002 to 0°013 ; and it is certain that 
the presence of silicium disposes iron to corrode, although in 
dissolving in menstrua it may sometimes act as a mechanical 
protector, covering it with a coat of silex. 

41. M. Born has also observed that iron cast in “dry sand,” 
or “in loam’? moulds faced with charcoal, oxidates much less 
speedily than when cast in green sand ; and that “‘chilled”’ cast 
iron, or that cast in iron moulds, is the least of all susceptible 
of this change.—(Comptes Rendus, 1837.) 

42. Becquerel, in remarking upon these statements, observes, 
that cannon which are cast of close gray iron, and in “dry sand,” 
sustain little alteration further than a single coat of rust, or 
browning like a gun-barrel, which seers to suspend further 
action. This he attributes to the charcoal facing of the mould; 
and adds, that if it were possible to carburate the surfaces of ob- 
jects cast in iron in the operation of moulding, this alone would 

~preserve them from further oxidation. There appears, how- 
ever, here to be a serious mistake ; the presence of a carbona- 
ceous coat on the surface of cast iron, unless impervious to air 
and water, cannot preserve it from rust, however uniformly 
spread. That it should do so, would be at variance not only 
with the observed facts, and with the circumstance that the coat 
of plumbago formed by the action of sea-water on iron does not 
preserve the remainder, but is at variance with an experiment 
of Becquerel himself, in which he shows that the application of 
a piece of common charcoal to the surface of iron in a solution 


270 EIGHTH REPORT—1838. 


of sea salt and sub-carbonate of soda greatly promotes its 
oxidation. Unless, then, it were impervious to the fluid agent, 
it could never prevent the oxidation, however ufiform. 

43. It cannot have escaped the notice of any one who has had 
an opportunity of observing castings, with what rapidity the 
water of a fresh-fallen shower of rain, which is highly charged 
with oxygen, attacks fresh-made castings of iron; and this;. 
according to my observation, more rapidly in “dry sand”’ or 
“loam” castings than those made in damp or *‘ green sand,” 
contrary to the opinion of the French engineers: which I at- 
tribute to the circumstance, that in “loam” or ‘‘ dry sand” 
moulds, moisture not being present, but little hydrogen is 
generated by the fluid metal to burn off the “ facing” of char- 
coal, which remains “ parsemé”’ on the surface of the casting, 
producing innumerable voltaic couples in contact with water ; 
while, in the case of “‘ green sand ”’ castings, most of the char- 
coal facing is removed in a gaseous form from the casting before 
it leaves the sand. 

44. “Chilled”? cast iron, or that whose substance, to a greater 
or less depth, has suffered an alteration of crystalline arrange- 
ment by having been cast in a cold iron mould, is unquestionably 
that which suffers least change, in a given time, in water 
charged with air, whether fresh or salt; and this from two di- 
stinct causes: first, from its greatly increased density and hard- 
ness; and, secondly, from the fact that a very large portion of 
uncombined carbon is pressed or squeezed out by the expansion 
of the crystals of iron at the moment of consolidation. 

45. I have presented to the Chemical Section two specimens 
of chilled cast iron, in which, by a little management, this phe- 
nomenon has been rendered very apparent. On these the sus- 
pended or uncombined carbon is seen exuded in the form of a 
metalline dew, and adherent to the surface in drops of various 
sizes. 

These specimens are interesting in another point of view, as 
affording decisive instances of the expansion of iron in con- 
solidating. 

I have also in my possession a piece of an unusually dense and 
white “‘chilled”’ iron, of large dimensions, whose entire substance 
is filled with interspersed octohedral crystals of apparently 
pure carbon. They are nearly all of equal size, the principal 
axis of the crystal being about one twentieth of an inch in 
length. ‘They are hard enough to scratch quartz, and are ex- 
ceedingly obvious and striking from their dark colour, compared 
with the iron in which they are imbedded, the grain of which 
also is brilliant and highly crystalline, 


Gare eee 


aes 


pone 


ACTION OF WATER ON IRON. 271 


46. It has been considered by most authors that “‘chilled”’ or 
white cast iron contains less combined carbon than the black 
or gray varieties ; this, however, appears to be a mistake; yet 
it is undoubtedly true that it does contain much less carbon or 
graphite in a suspended or uncombined state, and that the latter 
is mechanically expressed and locally deposited in much the 
same way, as the author has endeavoured to show in another 
place,—that the contemporaneous quartz veins in granite have 
been formed from the residual quartz existing in that rock, over 
and above that which was necessary to the atomic composition 
of its constituent minerals. It is also analogous to the ob- 
servation made by Pelletier respecting the combination of 
phosphorus and silver, viz. that this metal holds more phos- 
phorus in combination, or rather in suspension, while in fusion 
than when solid, for at the moment of congelation of fused 
phosphuret of silver it exudes a quantity of phosphorus, which 
takes fire, unless the whole be suddenly cooled in water.— 
(Ann. de Chim. vol. xiii. p. 110.) 

47. By two remarkable properties may the whole of the 
metals be divided into as many classes, namely, those which 
pass from the fluid state of fusion instantaneously to the solid ; 
and those which assume the latter state by passing through an 
intermediate condition of pastiness. 

The former property is exemplified in all the metals which 
crystallize best, as bismuth, zinc, arsenic, &c.; and the latter in 
potassium, aotliteas iron, platina, &c. The power of being 
welded is entirely due to this latter condition of intermediate 
pastiness between fluidity and solidity, and hence it is properly 
not confined merely to metals, for wax, tallow, resins, camphor, 
caoutchouc, glass, and most vitrifactions, have strictly the 
welding property. 

But it results from this that those bodies which can be 
welded can. scarcely ever be crystallized by fusion and slow 
cooling, because that pasty and viscid condition they assume 
before solidification forbids the freedom of motion to their 
molecules, which is essential to their crystalline arrangement. 

But in “ chilling’’ cast iron by sudden cooling, time is not 
given it to assume the viscid or pasty state; its particles are 
compelled to pass per saltum from a liquid to a crystalline solid, 
and, e converse, by continued cementation at a temperature ap- 
proaching its fusing point, ‘‘ chilled’’ cast iron may be brought 
back again to the ordinary grain of common cast.iron. By this 
instantaneous change, the crystals of iron in forming, in obe- 
dience to the general law, reject and throw out the uncombined 
carbon as heterogeneous, which itself also assumes the cry- 


272 EIGHTH REPORT—1838. 


stalline form. We see here, also, the close analogy to the pheno- 
mena and properties of unannealed glass, that is, of silicates 
which have been compelled suddenly to pass from the semi-fluid 
state to that of solidity, without passing through the pasty con- 
dition. In these the crystalline arrangement is distinctly pro- 
duced, as Sir David Brewster has determined by the optical 
examination of Prince Rupert’s Drops, and yet these, by being 
annealed, are brought back to the state of ordinary glass. ; 

48. Hence, then, the superior hardness and greater specific 
gravity of chilled cast iron. But while it accrues, from the 
chilling of cast iron, that it corrodes less rapidly, a singular 
and in some cases disadvantageous circumstance occurs in the 
manner of its corrosion, which needs further consideration, as it 
may sometimes happen to be of much greater practical im- 
portance than ary amount of mere decay of substance. 

49. When a piece of cast iron moulded in sand is exposed to 
corrosion, this takes place with somewhat variable, but yet with 
very considerable uniformity over its entire exposed surface. 
Not so, however, with chilled castings ; in these, each nucleus 
of exudation of its uncombined carbon forms with the iron in its 
immediate vicinity a voltaic couple; and its results are, that, 
in place of the uniform action as before, the largest portion of 
the surface remains unchanged, and corrosion is nearly wholly 
confined to these spots, as so many local centres of action. The 
oxides of iron are formed as usual; but, from the texture of the 
casting, and its constitutional carbon being all in a state of 
combination, little or no carbonaceous or plumbaginous matter 
is produced ; hence, as the spots of carbon form, with the rest 
of the casting, so many voltaic couples, the oxides formed are 
rapidly transferred to these points, and gradually produce large 
tubercular concretions, which, M. Payen states, always consist 
of (Fe O)+(Fe,0O,+ FeO)+(Fe, 0), and which in course of 
time contain crystals of the octohedral iron ore thus artificially 
produced. 

50. M. Payen has presented several memoirs to the Academy 
of Sciences on the subject of these local actions on iron, and has 
applied to their explanation the facts he had previously disco- 
vered, as to the effects of alkaline and saline solutions in retard- 
ing or accelerating the corrosive action of water on iron. The 
principal facts he has established are the following, as given by 
the Commission of the Institute, in reporting on his memoir.— 
(Comptes Rendus, Feb. 1837, No. VI.) 

“* He has found solutions, containing an alkali and sea salt in 
such proportions, that, in place of being at all preserved, iron 
placed therein was rapidly attacked. 


ACTION OF WATER ON IRON, 273 


“¢ A cylinder of iron, filed bright, is preserved for a long time 
from all alteration when plunged into a solution of pure potass 
diluted with one thousand times its weight of water ; but if the 
solution be left in contact with the air, the alkali, absorbing 
carbonic acid, by degrees loses its preservative power. 

“When the water contains +2, of its volume of a saturated 
solution of carbonate of soda, it forms conical concretions of 
oxide,’’ &c. 

What is more remarkable in this mode of alteration is, that 
all points of the surface of the metal are not equally attacked ; 
the action commences where there are breaks of continuity, or 
where foreign bodies are deposited, which constitute, by their 
contact with the iron and the liquid, a voltaic couple: all the 
rest of the surface preserves its metallic lustre. 

“A saturated solution of sea salt preserved from contact of 
air only produces some excrescences of oxide of iron; while, if 
exposed to air, oxidation goes on as usual. 

‘*When this solution is saturated with carbonate of soda it 
possesses the property of preserving iron from all alteration, 
even though exposed to air, but it loses it when the solution is 
diluted. 

“It might be presumed that this difference arose from the 
saturated solutions containing less air than the dilute, but this 
cannot be so, since M. Payen has proved that the proportions 
of alkaline bases capable of arresting all oxidation eliminate but 
a very small portion of the air contained in the water. 

‘*M. Payen has determined the proportions of sea salt and 
sub-carbonate of soda which accelerate the formation of tuber- 
cles (or local corrosion) most. A solution of these two salts, 
diluted with 75 times its volume of Seine water, produced, 
in less than a minute, on cast and wrought iron, a commence- 
ment of oxidation, indicated by light green points, which, in 
less than ten minutes, formed visible projections.” 

The effect is increased by applying to the surface a fragment 
of charcoal, in which case a voltaic circle is formed ;—“ Hence,”’ 
says the Report, “in similar circumstances, cast iron will alter 
more rapidly than pure iron.” 

We see, then, that solutions which have a feeble alkaline re- 
action possess the property, in presence of air and sea salt, of 
producing on cast and wrought iron, which they moisten, local 
concretions which preserve the remainder of the surface from all 
change; and that these effects vary according to the proportion 
of the different salts, breaks of continuity, and the foreign bodies 
adherent to the surface of the metals. 

“*M. Payen thinks that the concretions formed in the pipes 


274 EIGHTH REPORT—1838. 


which supply Grenoble with water (presently to be described) 
are formed in this way, the waters which pass in them having a 
feeble alkaline reaction, owing to the presence of carbonate of 
lime, and being slightly saline. 

“‘ At the suggestion of the Commission, M. Payen incrusted 
pieces of wrought iron in cast iron, and fragments of cast iron 


in plates of cast iron of another sort: in all these cases he found- 


the tubercular oxidations adhered to the points of contact. 

“‘It may be concluded (they continue), from the observed 
facts, that whenever there is a want of homogeneity in cast-iron 
pipes, which convey water slightly alkaline and saline, tubercles 
will be formed at the points where heterogeneity exists. M. 
Payen has studied the circumstances in which, as regards the 
formation of tubercles, white cast iron produces the same effect 
as gray or black;” having diluted one volume of a solution of 
carbonate of soda and of chloride of sodium, saturated at a 
temperature of 15° Cent., with from 100 to 200 volumes of 
distilled water, he has found that all the solutions between 
these limits produce on white cast iron oxidations evidently 
more tubercular and better localized than on the other kinds of 
cast iron. These last afford more points of easy attack, and 
produce more numerous tubercles, and hence less distinct. 

“‘ We see, then, that white cast iron, as being less oxidizable 
by certain mineral waters, appears to merit the preference over 
gray iron for water-pipes.”’ 

The reporters further add, ‘‘ We are not obliged to say that 
the constitution and composition of the artificial tubercles are 
the same as those of the pipes at Grenoble, which would tend to 
prove that both depend on like causes.” 

51. This local action, in many cases, is of small importance, 
and indeed might be more advantageous than that deep removal 
of metal which takes place in softer irons; but in the case of 
pipes or similar receptacles for the containing or conveying of 
water, the accumulation of these tubercular excrescences gradu- 
ally chokes the passages at numberless places, and obliges the 
removal of the whole conduit. Nor does this evil solely apply 
to chilled cast iron; all hard cast iron which has been rapidly 
or unequally cooled is pro tanto liable to the same. 

52. M. Vicat, in the Comptes Rendus, vol. iii. 1836, p. 181, 
gives an account of the formation of these tubercles on the pipes 
which supply Grenoble with water, in which they had increased 
to such an extent as seriously to reduce the delivery of water, 
and engaged the attention of the authorities. He proposed as 
a remedy the coating of the pipes inside with hydraulic mortar 
to the thickness of 24 millimeters,—in fact, to brush them over 


~ 


~ 


ACTION OF WATER ON IRON. 275 


inside with Roman cement. This mode would no doubt for a 
time diminish corrosive action, but it is much to be feared that 
it could have but little permanence when the current was rapid ; 
and, should the water contain much earthy matter, the tendency 
of this to deposit and adhere to the pipes must be fatally 
increased. 

53. The Academy appends a note to M. Vicat’s communi- 
cation, in which an opinion is expressed, that the tubercles of 
Grenoble have attained their largest size, and are stationary ; 
and it is questioned, Will they always remain so? It must be 
obvious, indeed, that the rate of increment of these must be a 
decreasing one; but I do not perceive anything to set a limit to 
their accretion, except the stoppage of corrosive action. 

54. In the same volume of the Comptes Rendus, p. 462, a 
letter is published, from M. Prunelle, stating a case in which 
tubercles had formed in conduit pipes where the water passing 
was found not to contain a trace of iron. He did not chemically 
examine the tubercles, which were friable, and as large as eggs. 
From this it would seem to be the author’s view that these 
masses originate from iron contained in the water; that this, 
however, is not the nature of their formation, has been already 
shown, and is evidenced by the fact, that no tubercles are found 
in any of the pipes conveying the waters of Grenoble except 
those made of iron.—(Payen, 4nn de Chim. vol. lxiii. p. 409.) 

55. The explanation of the phenomena of tubercular cor- 
rosion given by M. Payen and the reporters to the Academy, 
seems to lose clearness in proving too much. Mere want of 
homogeueity of structure or of surface is alone sufficient ground 
to explain the results; and that the peculiar preservative action 
of alkaline solutions is not a necessary adjunct, I have lately 
had an opportunity of proving. In experimenting on the action 
of very dilute hydrochloric acid, on wrought and cast iron par- 
tially coated with zinc, I found that, after a time, local con- 
cretions or tubercles were formed at the points of contact of the 
zine and iron ; thus the effect is produced indifferently in acid 
and in alkaline solutions. And I have since found tubercles 
formed in iron pipes at Curraghmore, the seat of the Marquis of 
Waterford, by water, which appears free from alkaline or earthy 
matter. The peculiar effect, too, is confined to chilled or un- 
equally-cooled cast iron, to mottled cast iron, and to damasked 
wrought iron, or that of mixed constitution, and in all appears 
to result from heterogeneity of composition ; it is therefore un- 
necessary to call in to the aid of the explanation the distinct 
and curious phenomena of the preservative action of alkaline 
solutions. 


276 KIGHTH REPORT—1838. 


In further corroboration of which may be again noticed M. 
Payen’s own experiment,—that wrought iron locally encrusted 
with cast iron, by dipping into the latter while fluid, or pieces of 
cast iron cast into and surrounded by plates of a different sort 
of cast iron, are liable to like tubercles, which attach them- 
selves to the points of contact; reasoning from which, Becquerel 


rightly concludes, that want of homogeneity is the cause of this . 


peculiar action. 

56. M. Payen, as we have seen from his experiments to de- 
termine the conditions in which white or chilled cast iron would 
be acted on like the darker-coloured varieties, concludes very 
erroneously on the practical maxim, that it is much “ better to 
make conduit pipes of white cast iron than any other, as various 
mineral waters will oxidate it less’’—and truly they will so ; 
but as the peculiar nature of the oxidation in this case stops up 
the pipes at intervals, any amount of uniform corrosion which 
merely sets a limit to their duration is to be preferred to this, 
which renders their entire object nugatory. 

57. Aletter is found in the Comptes Rendus for 1836, p. 506, 
from Sir John Herschel, stating that the pipes supplying Cape 
Town with water had become tubercular; and that, at his re- 
commendation, the engineer, Mr. Chisholm, had remedied this 
by coating the pipes internally with Roman cement. The 
ancient pipes in the streets of Dublin are likewise much affected 
in this way; and some fragments of the tubercles, and a piece 
of the cast iron, which is of the white variety, were presented 
to the chemical section at Newcastle. 

58. Another method for preventing tubercular céncretions 
has been employed successfully by M. Juncker, at Huelgoat 
mine, in France, viz. that of impregnating the cast iron of 
which the pipes are made with linseed oil, rendered drying by 
litharge, and caused to penetrate the pores of the iron by great 
pressure. This fact is confirmatory of a preceding observation 
I have made, as to the permeability of cast iron to many sub- 
stances, and seems to offer a new field of investigation, as a 
method of protecting cast iron from the action of corroding 
agents. We know that it has been long usefully applied to 
other hard and crystallized substances, as stone, marble, &c. 

59. Another method, wholly mechanical, is described in the 
Mining Review as in use in Cornwall for the preservation of 
iron pipes, and must be eminently useful in many cases. 

Each length of pipe is lined with a thin tube of wood, con- 
sisting of staves of pine, of equal length with the pipe, driven 
in from the end, and to which the iron pipe forms, as it were, 
one elongated hoop. The pine staves are driven in when very 


ues 


ACTION OF WATER ON IRON, 277 


dry. On being wet, they expand, and force themselves up so 
close to the interior of the pipe, and at their joints, that the 
whole cast-iron pipe becomes staunchly lined with a casing of 
wood, which cuts off all communication with the corroding 
agents. 

60. The difference in the rate of action of air and water, but 
still more of acids, on different specimens of cast iron, contain- 
ing variable minute quantities of foreign matter, is very remark- 
able. The iron obtained by the remelting of old coal-gas 
retorts is of a quality closely approaching what is called “‘ Re- 
finery Pig, or No. 4;”’ in fact, by a little management, it may 
be forged at once on "the anvil into a bar. Itis found to contain 
a large quantity of sulphur, and an unusual amount of silex, in 
some cases as much as 18 per cent., with very little carbon. 

A fragment of this iron placed in hydrochloric acid, diluted 
with 15 volumes of water, will not be dissolved for months, a 
coat of silex being apparently formed; while a fragment of the 
iron before mentioned as containing chloride of sodium in mi- 
nute quantity, with a large proportion of sulphur and carbon, 
will dissolve in the same acid almost as readily as sugar in 
water. 

Sulphur, also, which acts on wrought iron with such intensity 
at a bright red heat, acts. on black cast iron, according to 
Colonel Evans, at the same temperature with comparative 
feebleness.—(Ann. de Chim. vol. xxv. p. 107.) 

61. Both these highly sulphuretted irons seem to coordinate 
with the highly carburetted ones, or black cast irons, the sulphur 
appearing to form a definite compound, intermixed with the rest 
of the substance mechanically. 

62. Of the relations in respect of corrodibility subsisting be- 
tween the different known varieties or ‘‘ makes”’ of bar iron and 
of steel, but very little is established with any certainty. The 
hardest kinds of malleable iron generally appear to oxidize 
slowest, but this is not universally true, as Swedish iron is acted 
on by air and water with great rapidity. 

63. Karsten states that cold short iron is rapidly corroded. 
Steel appears less corrodible than any variety of wrought iron ; 
but of none of these is there any precise knowledge on our sub- 
ject, or that approaches numerical results, which alone are of 
practical use in directing the engineer, or indeed the physicien. 
Neither is our actual knowledge more advanced as to the variable 
effects of corrosive action on the same iron, of different waters, 
such as are commonly met with, containing their usual mineral 
ingredients in solution. We know not whether foul water, or 

VOL. VII. 1838. T- 


278 EIGHTH REPORT—1838. 


clear water, strongly saline, or merely brackish, calcareous, al- 
kaline, or chalybeate, holding much or little carbonic acid, acts 
most powerfully in producing rust, that is, produces the largest 
quantity in a given time from any one specimen, or in what re- 
lative degree. This statement is made exclusively, of course, of 
the better-understood cases of mine-waters, such as solutions of 
sulphate of copper, &c., whose action on iron belongs to another 
branch of our subject. 

64. There are some cases of local action on wrought iron, 
however, which appear remarkable, and need investigation. 
The very purest and finest specimens of wrought iron, when ex- 
posed, with turned or bored surfaces, to fresh water, frequently 
corrode entirely locally, by deep and destructive pitting. A 
portion of a turned wrought iron valve was presented, acted on 
in this way, in about two months, by a remarkably pure stream 
of fresh water, holding nothing but air and a trace of carbonate 
of lime and iron in solution. This sort of reaction appears the 
converse vf M. Payen’s tubercles, and its explanation would 
seem to lie in the iron so affected possessing a damasked 
structure, that is, in fact, being composed of two sorts of iron 
chemically different, and united by welding. This is unavoidably 
the case with all “ scrapped’’ wrought iron, or that forged or 
rolled from scraps of various sorts. Now these differently-con- 
stituted irons, being in different electrical relations, give rise to 
a voltaic circuit, in which the most positive is corroded fastest ; 
but as all the surface is in some degree affected, the oxides 
formed cannot adhere, and hence, while pitting goes on in some 
places, tubercles are formed in none, This view suggests the 
importance of having large bars, which require to be formed 
by rolling several smaller ones together, formed from iron all 
of the same ‘‘ make,”’ if for any important purpose as regards 
durability. 

It shows that rolled bars, as being more uniform, are pre- 
ferable, for the same reason, to ‘‘ scrapped’”’ or hammered iron ; 
and it points out that the practice adopted im some cases of 
making railway bars by rolling together two bars of different 
sorts of iron, the one hard and rigid, to give a durable upper or 
working face to the bar, and the other tough and soft, to resist 
extension, is highly objectionable as regards the duration of the 
rail, under the influence of air and moisture—eminently so, be- 
cause the lower segment of the rail, viz. the extended part, will 
corrode the fastest, thus losing strength where it is most wanted. 

65. There were also presented the two extremities of a bar of 
wrought iron found at the bottom of a very deep well in a 


ACTION OF WATER ON IRON. 279 


brewery in Dublin*, where it was supposed to have lain in about 
20 feet of water for nearly eleven years. 

The bar lay approximately due north and south, horizontally. 
When taken up it was found powerfully magnetic, with polarity ; 
and though the bar was throughout equally exposed, corrosion 
had alone taken place at its two extremities. The ends were 
injudiciously cut off, by which its magnetism was almost de- 
stroyed. This curious subject needs further elucidation. It is 
doubtful if any authentic instance has yet been given in which 
magnetism appeared directly to play a chemical part. And the 
question is one of considerable importance as regards our sub- 
ject ; for, as it is well known that bars of iron, by long standing 
in the vertical or certain other positions, acquire magnetic pro- 
perties; if it should be found that magnetic polarity exercises 
any direct effect upon chemical agencies, then it may result 
that the duration of a structure in iron may in some degree de- 
pend upon the position of its parts with respect to the magnetic 
poles of the earth. 

Long since, Professor Maschmann, of Christiana, published 
some curious experiments, which were confirmed by Hansteen, 
on the effects of a magnet on the crystallization of the Arbor 
Diane, in a U-shaped tube of glass, beneath or above which it 
was placed. (Quarterly Journal of Science, vol. xvii. p. 158.) 
His results, however, were denied by some British chemists at 
the time. 

66. Since that time, the investigation of this influence, which 
has been repeatedly asserted and denied, has been undertaken in 
a very careful and particular manner by Professor Erdmann. 
He first points out the number of delicate perturbing causes 
which may, and have occasionally led to mistakes, pointing out 
the effects produced by irregularity in the wires, handling them 
with the uncovered fingers, &c. &c.; and especially states that 
many repetitions of each experiment should be made. The bars 
and magnets which he had occasion to use were very powerful, 
some of them competent to lift 80 pounds. 

I. By experiments made to ascertain the oxidation of the 
iron wire, when under the influence of terrestrial magnetism, it 
was ultimately proved,—1st. That the oxidation of iron placed 
under water is not at all influenced by terrestrial magnetism. 
There is no point of the horizon towards which it is more 
strongly or more quickly produced than towards another. 2nd. 
The oxidation arising from unequal contexture of the iron 
always hegins at the point where the wire is in contact with 


* Messrs, Guinness, James’ Gate, 


1 2 


280 FIGHTH REPORT—1838. 


other bodies, not only metals, but even wax or baked earth. 
3rd. Diffuse daylight, or the weakened rays of a winter sun, 
neither retard nor assist oxidation, provided they are accom- 
panied by no change of temperature. 

IJ. In experiments made with magnetized wires, the results 
were the same; no difference of oxidation occurred at the poles 
or other parts. ; 

III. In experiments on the reduction of metals by the humid 
process, as in the Arbor Diane, no influence of terrestrial mag- 
netism could be observed. The crystallization took place in 
both branches of the syphon tube, and without reference to 
their direction. 

IV. In repeating the experiments with the additional power 
of avery large magnet, its poles proved not to have the slightest 
power over the formation or disposition of the crystal within. 

V. Numerous salts were made to crystallize slowly in vessels 
placed over the poles of magnets, with every care that their 
power as conductors of heat should not interfere. The mag- 
netism exerted not the slightest influence over the crystal- 
lization. In chemical actions, where gas was evolved, no 
difference in the rapidity of evolution, or quantity of gas pro- 
duced, occurred, when magnets were present or absent. 

VI. No evidence of the influence of the magnetic poles over 
the colours of vegetable solutions could be obtained. — (Bid. 
Univ., xlii. p. 96.) _ 

67. These apparently satisfactory experiments of Professor 
Erdmann are, however, again laid open to discussion by some 
curious results stated by M. Levol (dnnal. de Chim. vol. Ixv. 
p- 285), in a paper ‘* On the phenomena which accompany the 
precipitation of a metal in the metallic state by another, in 
presence of a third metal, exercising no chemical action; and 
on the circumstances which may modify the results.’’ In this 
the following statement occurs :— 

‘7 found a circumstance which appeared to me very curious. 
It is, that the position of the iron, during the precipitation (all 
other things being equal), is by no means indifferent as regards 
the separation of the copper (viz. from its solution). 

‘In varying in different ways the experiments which were 
requisite, I have observed that the results, which were accordant 
when I plunged the iron horizontally, ceased to be so when 
(making a double experiment) I placed in one the iron hori- 
zontally, and vertically, or nearly so, in the other. 

“Tn the first case I have constantly more copper on the 
platina (7. e. the passive metal), less iron dissolved, and delay 
of the complete precipitation. 


|| Eee 


ACTION OF WATER ON IRON. 281 


“ Insulation, or free communication with the substance of 
one of the two metals, having scarcely any influence on these 
sorts of reactions, as I have assured myself, and which also 
conforms to the properties (propriétés) of electric currents, I 
have thought that these variations might result from magnetism, 
acquired by the iron placed vertically; and, to try if in fact it 
had any influence on the decumposition of the salt, I plunged, 
in this position (viz. vertically), a bar of soft iron in a tube of 
glass containing a neutral solution of sulphate of copper, and 
corked it. As scarcely any disengagement of gas agitated the 
liquid, I saw that decomposition began towards the two ex- 
tremities of the bar, advancing progressively towards its middle 
point ; the two extremities and this point acting meanwhile on 
a magnetic needle, as the two poles and the neutral point of a 
magnet, and the poles changing by reversal in the usual manner. 
The effect of this magnetization appeared then to augment che- 
mical action, and hence to diminish the quantity of copper de- 
posited on the platina.”’ 

Are we to conclude from this that magnetism modifies che- 
mical action, or that chemical action is capable, under certain 


conditions, of conferring magnetism on iron ? 


The subject is obviously in need of much further experiment, 
and is one of interest in a general, as also in our particular view. 
68. It will be now necessary to state the nature and extent of 
the experiments upon the large scale which have been instituted 
at the desire of the Association, and aided by its funds. On the 
very first consideration, it appeared important that those expe- 
riments in which time was an element should be first of all put 
in progress ; and of these the most important seemed to be, 
lst. To obtain experimentally a set of numerical results of 
the relative rates of corrosion of all the different most im- 
portant makes of British cast iron, exposed under the same 
circumstances to sea water, and unprotected, except from 
mechanical abrasion; and a like set for fresh water, va- 
rying the conditions in both cases as far as might occur in 
practice. 

With this view complete sets of authenticated specimens of 
cast iron from most of the principal iron-works in Britain have 
been written for and obtained. A very considerable delay ne- 
cessarily occurred in procuring these, and it was not until 
about two months since that it was found practicable to com- 
plete the collection, which numbers between eighty and ninety 
specimens. 

These specimens were then all fused, at the works with 
which the writer is connected, separately in crucibles, to avoid 


282 EIGHTH REPORT—1838. 


change of composition by contact with the fuel, and cast in 
green-sand moulds into the form of parallelopipeds, of 5 inches 
by 5 inches x 1 inch thick, and of 5 inches by 5 inches x 3 
inch thick, respectively ; and at the same time a bar of 1 inch 
square and 12 inches long was cast of each description of iron. 
The whole of these specimens, whose surfaces are as nearly 
equal as possible, were then weighed each to a single grain, or- 
within about 7,5 455 of the weight of the piece, and inclosed in the 
external frame of the box (fig. 1, as shown in Plate XVII.), No. . 
This box is so contrived as to permit free access of air and sea 
water at all sides, and while the specimens of iron are held fast 
at four of their angles, they are freely exposed to the action of 
these agents ; but each in a separate cell, for a reason to be here- 
after mentioned. As any mode of numbering these specimens 
would be inadmissible, if not impracticable, they are to be re- 
cognised when reexamined solely by their place in the box. 
The series commences at A. fig. 1, and reads from left to right, 
going upwards, as more particularly described in the notes at- 
tached to the tables. No iron used in the construction of the 
box enters its interior, and the specimens, with the frame in 
which they are arranged, can be lifted out at any time for in- 
spection, without disturbance of their position or touching their 
surfaces. This box, like the others to be described, is of stout 
oak kyanized, which, although the researches of Lassaigne upon 
this subject, showing that the combination of albumine and bi- 
chloride of mercury is soluble in alkaline chlorides, renders it 
probably of less service in sea water, yet is not likely to inter- 
fere in any way with the results of these experiments. 

69. The object of casting the parallelopipeds of two thick- 
nesses, viz. 1 inch and { inch, is, that the * grain”’ or crystalline 
arrangement, and proportion to the metal of ‘‘ skin,’’ as it is 
technically called, varies with the scantling of the casting: 
hence these thin castings will give results discovering what 
variety of British metal produces a skin best calculated to re- 
sist corrosion, and what amount of variation of skin each sus- 
tains by difference of thickness in casting. 

70. The castings were all poured, as nearly as possible, at 
the same temperature, (the crucibles having been heated in 
draught furnaces,) and all permitted to cool at the same rate. 

Their forms being all regular, and their dimension and weight 
known on again weighing after taking up and cleansing from 
adherent matter, a set of numerical results will be obtained, 
giving the relative rates of degradation in sea and fresh water, 
of most of the British cast irons per unit of surface; thus ena- 
bling the engineer to choose that which will be most durable in 


ACTION OF WATER ON IRON. 283 


his structures, and enabling us, by analysis of the least and 
most corrodible, to see on what these properties depend. Hot 
and cold blast iron are included in this box, and also specimens 
of the same cast iron chilled, and cast in loam, dry sand and 
green sand, cooled rapidly and slowly, and some with protected 
surfaces, (not electro-chemically protected however,) as will be 
again alluded to. This box was sunk and moored in Kings- 
town harbour in 34 fathom water, at half tide, at the second 
mooring buoy in from the western pier head, at one o’clock, on 
the 3rd of August (1838), on a bottom of clean sharp sand; 
temperature of the water, 58° Fahr. It is proposed being 
weighed and examined once every six months if possible, and 
at the expiration of a year the specimens weighed accurately 
and again put down, and so weighed year by. year for at least 
four years. By this, not only the actual amount, but the rate 
of progress of corrosion on every specimen will be determined. 

71. The object of casting the inch-square bars 12 in. long, of 
each sort of iron, at the same time with those exposed to the 
sea and fresh water, is in order to have specimens, comparable 
in all respects with these as to constitution and texture, whose 
specific gravities have been, or are in progress of being, taken, 
and whose chemical or physical properties can be in future de- 
termined, should the progress of the experiments on the exposed 
pieces render such desirable. 

There is the utmost variability of structure and composition 
amongst these specimens, as will be observed by referring to 
the column of observations in the table, but can only be fully 
perceived by inspection of the castings, when fresh broken. 
As an accurate knowledge of the specific gravities of these spe- 
cimens was of some importance in several respects, and chiefly 
as being a check upon the weighings, and upon the soundness 
and dimension of the rectangular pieces of iron, submitted to 
experiment, some pains were taken in arriving at the best and 
most expeditious mode of proceeding. 

The common mode of taking the specific gravity of solids by 
weighing in air, and then suspending from a silk fibre or hair in 
water, is subject to many inconveniences and sources of error, 
as the variable quantity of the suspending thread wetted and 
immersed, its capillarity and the resistance of the fluid to free 
vibration of the beam, &c. &c., a modification was therefore 
adopted of the plan of weighing the solid in air and immersed 
in a given volume of water, which is weighed along with it. 

But as the cast irons, if broken into fragments sufficiently 
small to go into a common specific-gravity bottle, would be 
likely to involve air bubbles hard to be extricated, each speci- 


284 EIGHTH REPORT—1838. 


men of cast iron whose specific gravity was required was filed 
accurately by a steel gauge to a cube of 0°75 of an inch; this 
cube was weighed in air at a temperature of 60° Fahr. A small 
glass cylinder was provided capable of being closed air tight at 
its open end by a circular disk of thin Bohemian plate glass, 
equal in diameter to its exterior. The size of the cylinder was 
such as just to admit, without contact at the angles, a cube of. 
the above size, and its weight with the plate-glass cover, was 
under 100 grains when empty. Its weight was then accurately 
determined from the mean of a number of weighings, when 
quite full of distilled water, free from air, at 60° Fahr. The 
filling is easily accomplished by pouring in the water after 
having been boiled in vacuo and cooled, until its surface rose a 
little above the edge or top of the cylinder, and then sliding on 
the glass plate. A number of the iron cubes having now been 
weighed in air were thrown into a considerable volume of di- 
stilled water at 60°, and placed under the exhausted receiver 
of the air pump, and agitated until all air bubbles had escaped. 
The glass cylinder being filled as before, each cube was taken 
out of the water by forceps and placed in the cylinder, from 
which it of course expelled its own bulk of water; the cylinder 
was now closed, dried rapidly in bibulous paper with gloved 
hands, and weighed, the temperature of the apartment being 
preserved carefully at 60° Fahr. 

It is sufficiently obvious from these data that we get the spe- 
cific gravity from the formula 

w 
—where S is the specific gravity of cast iron, w=the weight of 
a cube of distilled water =0°75 of an inch, s=the specific gra- 
vity of water, and W the weight of the cube of cast iron, 
equal in volume to the cube of water. 

This method possesses several advantages in rapidity and ease 
of execution, and in precision of result, besides involving a check 
upon any serious error of experiment in every instance; for as 
each cube is weighed in air, and the weight of a cubic inch of 
distilled water at 60° Fahr. is well determined, the specific gra- 
vity of each cube is at once known within the limit of error in 
the gauged dimensions to which the cast iron cube is filed. 
There was found to be no difficulty in drying the outside of the 
cylinder, so that it did not change its weight in the balance, i.e. 
perfectly, and no sensible evaporation took place from under 
the plate-glass disk, after remaining in the balance for forty- 
eight hours. 


ACTION OF WATER ON IRON. 285 


[have entered rather at length upon the mode of taking these 
specific gravities, because the method in its details will be found 
useful in other researches, as in taking the specific gravity of 
small mineral specimens, &c., and because the precise determi- 
nation of the maximum and minimum specific gravity of cast and 
wrought iron is of importance to the iron founder and engineer, 
as giving the data upon which the weight of castings are esti- 
mated, and which, as usually stated by authors, are an unsafe 
guide, inasmuch as the specific gravity of cast iron varies with 
its composition, the way in which it is cast, the rate of its cool- 
ing, and the depth of the mould, to an extent not generally 
known. 

72. 1 was favoured by my friend Mr. William Fairbairn, of 
Manchester, with a few specimens of the same hot and cold- 
blast irons, on which he and Mr. EK. Hodgkinson experimented 
as to their cohesion, so that not only the physical properties of 
these will be known from the experiments of these. gentlemen, 
but their durability from the present. 

73. Some specimens of Irish iron from the Arigna works, 
county Leitrim, are also included, and some experiments, made 
by Messrs. Bramah, of London, upon its strength are given, on 
the authority of the agent of the works, as an appendix to the 
tables, by which it will appear, that in point of cohesion this 
iron ranks with almost any in Britain, while its fluidity in 
casting recommends it as equal to the best Scotch iron. It is 
sold on the terms of the latter in the market.—This iron being 
scarcely known out of Ireland, these experiments and remarks 
will not be deemed irrelevant. 

74. Four other similar boxes have been prepared, which all 
contain a selection of specimens coordinating with those in 
No. 1. The second box, No. 2, is sunk and moored in the 
foul and putrid sea water at the mouth of the Kingstown town 
sewer, where it debouches into the sea. 

The water here is 2 feet deep at ebb, and from 8 to 12 feet. at 
flood tide, and a constant succession of bubbles of sulphuretted 
hydrogen and marsh gas pass through it from the deep deposit 
of mud which forms the bottom. 

Precautions have been taken to prevent the box of specimens 
sinking in the mud. The temperature of the water is 58° Fahr.; 
it contains as much saline matter, except during heavy rains, as 
the clear water of the harbour—its specific gravity, when filtered, 
being the same. 

The results of this experiment will determine the relative . 
actions of clear and foul sea water, when examined in the same 
way and at the same periods as No. 1. 


286 EIGHTH REPORT—1838. 


75. The box, No. 3, containing a similar set of specimens 
with No. 2, has been deposited, by permission of the Dublin 
and Kingstown Railway Company, in the hot-water cistern of 
their baths at Salt Hill, in clear sea water, maintained con- 
stantly at a temperature varying from 110° to 125° Fahr. The 
object of this experiment is to determine the change of cor- 
rosive action produced by increased temperature in sea water. 
containing but little combined air, and the differences of this 
action on various kinds of iron. 

76. Van Beek and Dr. John Davy appear to be of opinion, 
that sea water, after it has been boiled, is incapable of decom- 
posing iron from containing no air; at the temperature of 125° 
Fahr. decomposition is however most rapid, as the action of the 
sea water on the iron cisterns of these baths demonstrate ; and 
yet the water contains little air at that temperature. 

The results of my own experiments also show me, that after 
all the air is expelled that can be from sea water by boiling, it 
is still capable, at its boiling temperature, of decomposing iron, 
and that with a rapidity as great as at ordinary temperatures, 
however highly charged with air. In addition to which, there 
is no longer any reason to doubt the fact, that under such cir- 
cumstances the alkaline chlorides are in part decomposed by 
the iron as well as the other salts contained in sea water. 

77. Indeed Scoresby’s experiments appear to prove that it is 
impossible to deprive water, whether salt or fresh, of all its air, 
by any amount of even alternate boiling and freezing. He found 
that, on boiling briskly some sea water in a phial, and then 
corking the latter and exposing it to cold, as the water froze 
air bubbles began to appear moving upwards in the fluid, and 
the ice produced was full of microscopic air bubbles. Hence 
he concludes it probable, either that water is not entirely freed 
from air by boiling, or that some of the water is decomposed 
during the progress of the freezing process: of the latter there 
is no likelihood. 

Boussingault also states that he found 16 per cent. of oxy- 
gen in snow collected from the summit of Chimborazo in South 
America.—(dnnal. de Chim.) It is to be remarked, however, 
that, as has been observed to be the case with lead and some 
other metals, so iron seems to be corroded much more rapidly 
by air and distilled water at a high teniperature, than by water 
holding any alkaline or earthy salts in solution. The destruc- 
tive effects of a small leakage of steam producing a trickle of 
distilled water to steam boilers have often been observed by 
engineers. 

78. The experiments of Dr. Faraday on the order of deposi- 


ACTION OF WATER ON IRON. 287 


tion by boiling of the saline contents of sea water, and the re- 
spective temperatures at which each salt deposits, showing that 
they fall in the order of their respective insolubilities, indicate 
that important differences in the corrosive action of sea water, 
when boiling, may result from its degree of saline concentra- 
tion, and to this, the resulting boiling point, the electro-con- 
ducting power of the fluid, as well as the nature of the salts 
deposited and remaining in solution, are conditions. And, fur- 
ther, as means have been devised (although with increased ex- 
penditure of fuel) of preserving sea water in marine steam 
boilers, (or others using salt water,) at a constant degree of sa- 
turation, it becomes important to discover when this is such as 
to produce a minimum corrosion, whether before or after the 
deposition of the sulphate lime, or of the chloride, sodium or 
magnesium. 

79. The next box, No. 4, has been moored by permission and 
assistance of the Ballast Corporation of the port of Dublin, in 
the foulest water of the river Liffey, in the mid stream, opposite 
the mouth of the Poddle river, at this place a tributary of cor- 
rupted water. It lies in water 4 feet deep at ebb, and from 15 
to 20 feet at flood tides. The water is very brackish at full 
tide, and at the other periods fresh ; its temperature, when the 
box was sunk, was 61° Fahr. The specimens in this are the 
same as in Nos. 2 and 3, as may be seen by the tables. Its ob- 
ject will be to determine the relative effects of foul river water, 
alternately brackish and fresh, and this will again compare with 
the results to be obtained from the last box, No. 5. 

80. It has been sunk in the clear, unpolluted fresh water of 
the Liffey above Island-bridge, and within the premises of the 
Royal Military Hospital. It lies in water varying at times from 
3 feet to 6 feet in depth; its temperature varies with the season. 

Specimens of water have been taken from these five localities 
for examination, and will be again taken and examined from 
time to time. The highest and lowest temperatures of each 
will also be observed. 

81. In each of these boxes have been included a number of 
specimens, coated with various protecting varnishes and paints. 
—This was originally suggested by a fact of importance commu- 
nicated to the writer by Thomas Rhodes, Esq., civil engineer, 
whose experience in the construction of great works in iron is 
well known. He mentioned, that when engaged on the locks 
of the Caledonian canal, certain cast-iron sluices were put down 
and exposed to the ocean water, having been coated over with 
common Swedish tar, with the exception of their faces, 
which were ground together, and were removed in about four 


288 EIGHTH REPORT—1838. 


years afterwards: every part of the iron still covered with the 
tar was found sound and untouched as when put down; but the 
ground faces, which had not been tarred, were softened and con~ 
verted into plumbago to the depth of ? of an inch. 

This interesting and important observation shows that, where 
abrasion does not interfere, if we could get any coating to ad- 
here to the iron which would be impervious to air and water, - 
the preservation of the metal would be effected in the best and 
simplest manner. Unfortunately, many difficulties oppose this, 
and few, if any, varnishes can be obtained which will spread 
over the iron without leaving uncovered spaces or microscopic 

ores. 
‘ Professor Lampadius long ago directed his attention to this 
point, and, in the dnnales des Arts et Manufactures, published 
the composition of a paint or varnish for the preservation of 
iron from rust, the basis of which is sulphate of lead and sul- 
phate of zinc ground with plumbago and oil. It is difficult, 
however, to see the precise point aimed at by this composition. 

82. The paints and varnishes which have been placed in pro- 
cess of experiment in the above five various conditions are seve~ 
ral of those most ordinarily in use, with the view, that as no- 
thing certain is known upon this branch of the subject, the fate 
of these coverings, many of whose other properties are well 
known, may afford leading indications as to the direction in 
which improvement may be sought. 

83. As yet it has been impossible to arrange any experiments 
upon a large scale upon wrought iron, nor indeed to collect suf- 
ficient specimens; but there has been included in each of those 
five boxes a single parallelopiped, all of equal size, and cut from 
the same bar; it is of what is called common Welsh bar iron, 
or No. 1, and was made at Dowlais Iron-works, South Wales. 

This bar I have called ‘* The Standard,”’ and the remainder 
of it, which is some feet in length, is proposed being deposited 
with some learned body to be appointed by the British Asso- 
ciation. 

Now this standard being placed in each box in circumstances 
precisely similar to the rest of the specimens, it is imtended to 
take the action of the sea and fresh water upon 7¢ as unity, and 
refer their action upon all the other specimens to this, by which 
means not only will this whole series of present and projected 
experiments on wrought and cast irons be numerically compa- 
rable most conveniently by the engineer, but any future experi- 
menters upon novel makes of iron, or upon foreign ones, can, 
by reference to the standard bar in possession of the Associa- 
tion, make their experiments comparable with these. 


ACTION OF WATER ON IRON, 289 


Without this precaution the present experiments, although 
correct, would stand isolated, and be scarcely capable of being 
even brought into comparison with future ones. Nor could it 
be hereafter determined what change as to corrodibility, future, 
and now perhaps unthought of, revolutions in the manufacture 
of iron may produce in the metal to be made in years yet to 
come. 

84. The writer’s experiments also lead to the expectation, 
that with the same bar of iron, or the same casting, a simple and 
closely approximate estimate may be formed of its destructi- 
bility in water or in solutions of the alkaline or earthy chlorides ; 
by the rate of its solution in other agents; and with this view 
experiments are in progress upon the standard bar and other 
iron, and in the event of their results being found as here stated, 
it is obvious that upon the basis of the present prolonged ex- 
periments in sea water, the durability, under similar circum- 
stances, of all other or future irons may be determined in a few 
hours by the aid of this new method of examination. 

85. The subject now leads us to consider briefly the various 
modes of protection which have been proposed for the purpose 
of preventing, as far as possible, those actions of water and air 
on iron, the rate and nature of which our experiments have been 
directed to determine; and these, with the exception of mere 
superficial coverings, as already alluded to, have all been of the 
electro-chemical class, and more or less directly derived from 
Sir Humphry Davy’s original discovery and proposal of the 
protection of the copper sheathing of vessels. In that paper the 
great principle was developed of counteracting chemical by 
electrical forces; his successors have only, with greater or less 
perfection, developed and applied his brilliant idea to particular 
cases, while in doing so, it must be confessed, they have cor- 
rected some small errors into which this great philosopher fell. 
In Sir H. Davy’s original papers on the preservation of copper 
sheathing, he distinctly states, that it follows from his principles 
then developed, that cast or wrought iron may be preserved 
from chemical action by suitable protectors of zinc ov tin. 

But my friend Professor Edmund Davy has unquestionably 
the merit of having been the first to conduct a series of well- 
devised and careful experiments upon the subject on the large 
scale, which he did partly in connexion with the preservation 
of the iron work of the mooring chains and buoys in Kingstown 
harbour, under the auspices of the Board of Public Works. 
The results of these have been already communicated by him to 
the Association, at its meeting in Dublin, and published in its 
reports. 


290 EIGHTH REPORT—1838. 


The results of these investigations show that zinc is fully ca- 
pable of protecting cast or wrought iron in sea, or fresh water, 
when applied in a massive form, at least for a time. They also 
put in a forcible point of view the important part which the 
contact of air plays in the corrosion of iron. 

86. It would seem, however, to be doubtful how far this pro- 
tecting power even of zinc is completely permanent, for as a- 
portion of the oxide of zinc is transferred to the surface of the 
iron, as Professor Edmund Davy has observed, it would seem 
that the preserving power of the zinc is diminished. 

A forelock key, now presented, with which I have been fa- 
voured by Professor Davy, and which has been immersed in sea 
water for about three years, though protected by zinc in form 
of a ring loosely connected with it, is yet somewhat acted on, a 
crust of magnetic oxide being formed all over it, spotted over 
with the oxide of zinc; yet the action is incomparably less than 
it would have been in the same time and circumstances if wholly 
unprotected. My attention has also been drawn by Professor 
Miller, of Cambridge, to the curious fact, that the surface of the 
iron is covered in places with microscopic crystals of cale spar; 
these he was kind enough to examine for me with the gonio- 
meter, and although under very disadvantageous circumstances, 
succeeded in verifying their form as that of the common cale 
spar rhomb. This fact is interesting, as a new instance of the 
production of an insoluble crystallized mineral by galvanic cur- 
rents of low tension. 

87. Pepys long since proposed to preserve polished instru- 
ments of iron and steel from rust in air by zinc protectors. This 
seems to have been unsuccessful, and was found to be so by 
Professor Edmund Davy. 

88. Very lately a company has arisen in London, under the 
name of the “‘ British Galvanization of Metals Company,’’ based 
upon a patent for the protection of iron by coating its surface 
with fluid zinc, obtained by a French engineer, M. Sorel. I 
lately wrote to the secretary of this company, and have obtained 
specimens of the so-called galvanized iron, which are now pre- 
sented. I also wrote to another company, styled the “‘ Zincked 
or Galvanized Iron Company”: my letter was returned un- 
opened by the secretary. Having only received the specimens 
a very few days before the present meeting, I have been unable 
as yet to make many experiments upon them; some, however, are 
detailed in the prospectus of the company, of Professor Graham, 
Mr. Children, Mr. Garden, and Mr. Brand, which amount to 
this, that, as was to be expected, the zinc preserved the iron, in 
dilute acids, until the whole of it was dissolved, In the speci- 


a 


ACTION OF WATER ON IRON. 291 


mens furnished us, the iron, which is all wrought, (and its ap- 
plication to the more carbonaceous cast irons must be more 
difficult,) is zincked or, if the expression may be used, tinned 
with zinc ; the coating is excessively thin, and from its peculiar 
greasy feel, leads to the presumption that it has been slightly 
amalgamated also. 

89. I was enabled to detach from one spot a few grains of 
zine, which, on examination, appeared to be as pure as it is 
usually found in commerce. I expected to have found it alloyed 
with lead; of this it contains a trace, and a good deal of iron, 
probably taken up in part from the bar. No mercury could be 
detected in it. 

90. A very few minutes are sufficient to dissolve off the whole 
of the zinc from the surface of the iron when immersed in hy- 
drochloric acid, diluted with 40 volumes of water. 

91. Oxide of zinc is rapidly deposited in sea water or a solu- 
tion of common salt, when acting on it. 

92. When a bar of the zincked iron is placed in hydrochloric 
acid, diluted with 20 volumes of water, the zinc having been 
completely removed by the file from one half of its surface, hy- 
drogen is given off both from the zinc and iron surfaces from 
the first moment; and after the whole of the zinc is dissolved, 
this gas is much more copiously evolved from the surface that 
had been zincked, than from that from which it was filed off. 
This circumstance appears to be connected with the strength of 
the acid; it does not occur in that which is very dilute. 

93. There can be no doubt of the power of this combination 
to protect iron for a time, or while the thin coat of zinc lasts 
perhaps, and in some practical points of view it would seem to 
offer advantages over zine protectors, as proposed being ap- 
plied by Edmund Davy. But it seems to be forgotten by the 
advocates of this attenuated application of the preserving metal, 
that for every particle of iron protected, an equivalent of zinc 
must be destroyed, and that hence, unless a sufficient mass of 
the electro-positive metal is provided to allow for degradation, 
its efficacy must soon be null. 

94, It is not intended, however, to pronounce any decisive 
opinion as to the advantages or disadvantages of this peculiar 
mode of applying zinc protectors until we have had time to make 
other and careful experiments upon it; meanwhile, in justice 
to my friend Professcr Edmund Davy, I must remark upon 
the arrogation of original discovery to M. Sorel, the patentee 


_of this process, which some of the French scientific journals 


make. It does seem strange how any pretension to originality 
of discovery can be now set up on this score, after the previous 


292 EIGHTH REPORT—1838. 


publications of Sir H. Davy, Pepys, and Edmund Davy ; and still 
more, how a French patent is to be maintained for a process 
which, although its principle was doubtless then not under- 
stood, was, with little variation, before patented on the 26th of 
September, 1791, by Madame Leroi de Jaucourt, for preserving 
metals from rust by covering with an alloy of zinc, bismuth, 
and tin. I may add, that Professor Davy informs me he used - 
the method of zincking over the surface of iron as a preserver 
so far back as 1834. 

95. M. Sorel’s patent is described as capable of being ap- 
plied in three ways, viz. 1st, by covering the surface with fluid 
zinc; 2nd, by the application of a paint made from zine; 3rd, 
by covering with a powder made from zinc. Unless the second 
mean a paint made from ground metallic zinc, it is similar to 
Lapadius’ varnish, before described ; and if the former, then it 
does not differ from the third mode described, apparently. We 
have, however, not been furnished with specimens of either of 
these modes, which would seem beforehand not likely to answer 
their intended purpose, from a want of that continuity of me- 
tallic connexion which appears essential to preservation in this 
way. 
6. Sir H. Davy erroneously supposed that tin also possessed 
the property of preserving iron in sea water. «This opinion has 
been controverted by the experiments of M.Van Beek, of Utrecht, 
and of M. Mulder, of Rotterdam, and more recently by Profes- 
sor E. Davy, in a paper communicated to this Association, in 
which he shows that iron, on the contrary, will preserve tin, but 
that zine will preserve both. 

Sir H. Davy, and his brother Dr. John Davy, who has 
defended his opinion, appear both to have been led astray by 
merely considering and experimenting upon the galvanometri- 
cal relations of tin to iron when first placed in contact. But 
Van Beek, in the paper alluded to (Hdin. New Phil. Journal 
for October 1837,) has cleared this up by the discovery of the 
remarkable and anomalous fact, that although it is certain that 
tin is to iron in a positive relation in atmospheric air, yet when 
both are plunged into sea water, after a period, never greater 
than half an hour, has elapsed, the astatic needles of the galva- 
nometer, which had before indicated the above relation, gradu- 
ally return to zero, and pass through it to the opposite side, 
and indicate that the iron has become positive with respect to 
the tin, thus showing the singular fact apparently, that metais 
retain for a longer or shorter time the electrical condition they 
have once acquired. 

97. By decisive and direct experiments also, M. Mulder, of 


ACTION OF WATER ON IRON. 293 


Rotterdam, determines the corrosion of iron in presence of tin, 
and its amount :—Ist. A plate of iron weighing 32°907 grains 
was placed in a glass vessel containing one litre (= 61°028 cub. 
in.) of sea water, during 20 days, at the temperature of the 
month of November 1836 (at Rotterdam namely). After the 
experiment the weight of the iron was found to be = 32-726 
grains, loss by oxidation = 0'181 grain. 

2nd. A similar plate of iron, exactly of the same weight of 
32°907 grains, but on whose surface was fixed a small piece of 
tin weighing 8-140 grains, was in the same’manner exposed for 
20 days in one litre of sea water: the weight of the iron, after 
the experiment, was found to be = 32°674, that of the tin 
8:139 grains; hence loss by oxidation of the iron = 0:233 
grain, and loss by oxidation of the tin = 0-001 grain. These 
results show that the iron, when exposed to sea water as above, 
alone lost by oxidation 0°052 grain less than when in contact 
with the tin. : 

Van Beek, in recording these experiments, observes, that the 
action on the tin must have taken place at the first moment of 
immersion of the metals, and before it had become negative 


with respect to the iron.—( New Edin. Phil. Journ., Oct. 1837.) 


98. De la Rive has observed an analogous change of electri- 
cal state in these metals in a different research, and the fact is 
a very important one as regards our subject : it may possibly be 
hereafter found that the diminished preservative power of zinc 
to iron, after a length of time, has an analogous cause, as may 
the following like phenomenon. It sometimes happens that 
when one of Schcenbein’s inactive wires, and another rendered 
inactive by it, have remained together in a tube of nitric acid 
for a very considerable time perfectly passive, they at length 
suddenly, and without any assignable cause, both become active, 
and the reaction on the iron is so unusually violent, that most of 
the acid is instantly driven out of the tube with a sort of ex- 
plosion. 

99. We have now to consider the subject of a communication 
made at the last meeting of this Association, at Liverpool, by 
Mr. John B. Hartley of that town, upon the power of brass to 
preserve cast and wrought iron in sea water. Mr. Hartley is 
reported to have stated in the Chemical Section, that certain 
iron sluices having brass in connexion with some of their parts, 
had on examination been found perfectly sound and uncorroded 
in the neighbourhood of the brass, after an exposure of twenty- 
five years, but were corroded elsewhere; and that in couse- 
quence of this discovery, all the iron work below the tidal level 
employed in the Liverpool Docks had been placed in connexion 

VOL, VII. 1838, U 


re 


294 EIGHTH REPORT—1838. 


with brass in some way, and that its preservation had fol- 
lowed. . 

100. The statement created considerable discussion and atten - 
tion at the time, and at first seemed to Professor Davy and myself 
an important element in the subject of investigation with which 
we had been entrusted by the Association. Accordingly, very 
soon after the meeting, Professor Davy addressed Mr. Hartley. 
upon the subject, detailing the results of his previous experi- 
ments, and expressing his conviction of the non-protective pow- 
er of brass to iron, and assigning another and sufficient cause 
wholly unconnected with electro-chemical protection to the phe- 
nomena described by Mr. Hartley. A copy of his letter is an- 
nexed, as published in Saunders’ News-letter of Oct. 24, 1837. 


“To John B, Hartley, Esq., Liverpool. 


‘Royal Dublin Society’s Laboratory. 
« Sir, 

“You will I am sure excuse the liberty I take in addressing 
you, on an interesting and important subject on which you have 
recently been engaged, namely, preventing the corrosion of cast 
and wrought iron in salt water: I also have made many experi- 
ments with a view to the same object. I have to express my 
regret that the state of my health prevented me from taking an 
active part in the proceedings of the Chemical Section at the 
late meeting of the British Association for the Advancement of 
Science in Liverpool. I was not present when your paper * On 
preventing the corrosion of cast and wrought iron in salt water”’ 
was read and discussed. The object of it, as reported in the 
only two public prints I have seen, namely, Saunders’ News- 
letter of 15th Sept., and the Atheneum of the same date (the 
former of which I only saw yesterday), was to prove that brass 
protects cast and wrought iron from corrosion in salt water, 
without being itself corroded. It was also stated, that the iron 
so protected remained in excellent preservation after a period of 
twenty-five years. I must confess that these statements appear- 
ed to me to be not only anomalous, but in direct opposition to my 
own experiments, I have no hesitation in stating, as the result 
of my experience, that brass will not protect cast or wrought 
iron or steel from corrosion, either in salt or fresh water; but, 
on the contrary, these metals will protect brass from corrosion 
under such circumstances, at least for a limited time. 

«<T need not tell you that if brass were found to protect cast 


and wrought iron in salt water, suppose for ten days, the pre- é 
sumption would be, that it would do so for twenty-five years; — 


but if, on the contrary, brass will not protect iron for ten days, 


A 


ACTION OF WATER ON IRON. 295 


nor for a single day, which is the fact, then it would seem ab- 
surd to expect that it will protect them for twenty-five years ! 

“If I mistake not there is little difficulty in accounting for 
the preservation of the iron under the circumstances noticed by 
you, without having recourse to any fancied power of protection 
in brass, which it really does not possess. 

‘In Saunders’ News-letter already referred to, which con- 
tains the fullest report of your paper which I have seen, the 
iron is stated to be ‘an iron pin working in a brass socket, 
which was again inclosed in an iron case; all the iron in con~ 
nexion with the brass was in excellent preservation, whilst that 
removed from it. was corroded.’ 

** Now it seems clear to me that the preservation of the iron, 
under the circumstances here enumerated, was an effect due to 
the mere condition in which the metal was placed, which was 
such as precluded (almost entirely) the access of air, on which 
its corrosion, both in salt and fresh water, depends. Under 
similar conditions I entertain no doubt but that iron will pre- 
serve iron, and brass, brass, and each of these metals the other 
respectively; and glass, porcelain, &c., will equally preserve 
both brass and iron from corrosion in salt and fresh water. 
But the preservation of metals under such circumstances is not 
protection in the sense in which it has been commonly under- 
stood, since the first just views on the subject were advanced by 
the late Sir Humphry Davy. 

** As the protection of cast and wrought iron in salt water by 
brass is not only spoken of as a discovery, but has already been 
acted upon as such in some of the great public works in Liver- 
pool, and may soon be extended to other seaports, to our ship- 
ping, and to innumerable cases where iron is exposed to salt 
water, I lose no time in making you acquainted with my expe- 
rience and views on the subject. 

‘IT beg, in conclusion, to remark, that my statements pro- 
ceed on the ground that the brass spoken of, without any qua- 
lification, is no other than the common brass of commerce. If 
you have used a different alloy containing more zinc or other 
_ material, allow me to suggest to you the propriety of setting 
the public right on such a matter, as well as your humble ser- 
vant, 

“ Epmunp Davy.”’ 


Professor Davy has since favoured me with the following ad- 
ditional note containing the results of his more recent experi- 
ments on the subject, He proceeds :— 

101. ‘As the protection of cast and wrought iron in salt 

U2 


296 EIGHTH REPORT—1838. 


water by brass was not only spoken of as a discovery, but also 
acted upon as such in some of the great public works in Liver- 
pool,’ Professor Davy (who was not present when Mr. Hart- 
ley’s paper was read and discussed) lost no time in making Mr. 
Hartley acquainted with his experiments and views on the sub- 
ject, which he did in a letter inserted in ‘* Saunders’ News-letter, 
24th October, 1837.”’ In this communication Professor Davy - 
stated, as the result of his experience, “‘ that brass will not pro- 
tect cast or wrought iron either in salt or fresh water, but that, 
on the contrary, these metals will protect brass from corrosion 
under such circumstances at least for a limited time. 

** Professor Davy refers the preservation of the iron under the 
circumstances enumerated to the mere condition in which it was 
placed, being such as almost entirely precluded the access of air, 
on which its corrosion, both in salt and fresh water, depends. 

** Professor Davy was at first led to suppose that Mr. Hart- 
ley’s brass, which was spoken of without any qualification, was 
the common brass of commerce; but on learning that its com- 
position was different, he instituted experiments with Mr. Hart- 
ley’s brass, for specimens of which he was indebted to Mr. 
Robert Mallet. On trying the effects of this brass on iron in 
salt water, it had no more protecting power than the glass ves- 
sel in which the experiments were made. When the two metals 
were in close contact, the iron preserved its original brightness, 
as was also the case where the iron was in contact with the 
bottom of the glass vessel; but all the other exposed surfaces 
of the iron were corroded just as readily as if common brass 
were used with the iron.” 

102. In April last I wrote to Mr. Hartley requesting speci- 
mens of his brass, and of the iron preserved by it. I received a 
very minute portion of brass, and a piece of iron stated to have 
been in contact with it, together with a piece of plumbaginated 
iron, part of a sluice or paddle, through Mr. Gilbert Cummins, 
with the following letter :— 

“Dock Yard, Liverpool, 23rd April, 1838. 

**Srr,—In Mr. J. B. Hartley’s absence from England (he 
being at present on the continent, and not expected back for 
some time) I have to acknowledge the receipt of your letter of 
the 21st instant, and in accordance with your request have for- 
warded to your address, by the City of Dublin Company’s packet, 
a small parcel, containing a specimen of the brass composition 
referred to, and also of the cast iron preserved by it; the latter 
is part of the hinge of a large cylinder used as a valve to admit 
the ingress of sea water into a mill-dam or reservoir; the brass 
is a part of the bush with which the interior surface of the hinge 


ACTION OF WATER ON IRON. 297 


was lined. The bolt or pin for connecting the valve to the cy- 
linder is of wrought iron, which, as well as the cast iron, was 
found in a perfect state. I have also sent a piece of a cast-iron 
clough paddle, taken out of one of the dock sluices. When 
first taken up it was quite in a soft state, capable of being easily 
cut with a knife; but by exposure to the atmosphere has again 
become hard. 
“I am, Sir, your obedient servant, 
** GILBERT CUMMINS. 
“To Mr. Robert Mallet.” 


With this fragment, weighing only about 500 grains, we made 
a few experiments, and shortly wrote again to Mr. Cummins, 
requesting a larger supply of the brass, and replies to certain 
questions respecting its influence, as in annexed copy:— 


“Mr. Gitpert CuMMINS, 

‘¢ Sir,—In reply to yours of the 23rd instant, Professor Davy 
and myself return you our thanks for your attention, and for 
the specimens of altered cast iron and the brass, &c. just re- 
ceived. The specimen of brass is quite sufficient to enable us 
to determine its composition, but insufficient to enable us to 
institute some comparative experiments as to the precise condi- 
tions of its preservative power. For this purpose it would be 
necessary to have five or six pounds of the brass, the value of 
which, should that stand in the way, we are quite ready to pay; 
we therefore hope to receive it by the same conveyance which 
brought the former specimens. We would also desire replies 
to the following questions in your next— 

“1st. Is the brass—brass proper or gun metal, viz.—made 
with zinc or tin, and what, about, are its proportions ? 

“© 2nd. How long has it been in use as a preserver of cast 
iron, and to what purposes chiefly applied ? 

«3rd. How has the brass been chiefly applied? has it been 
cast into or round the cast iron preserved, at a temperature of 
fusion, or merely placed in contact at a common temperature ? 

“4th. Have its preservative effects been uniform, or have there 
been exceptions, and if so, under what conditions ? 

** 5th. Has its preservative influence been found as effective 
when the iron was exposed to ‘wet and dry,’ or akout the level 
of ordinary spring tides, as when always immersed in sea water? 

* 6th. Has cast iron in the neighbourhood of the brass, but 
not actually shielded or covered up from the sea water, been as 
well protected as when covered; for instance, would the pin of 
a hinge in a brass socket be better protected than the parts of 
the iron hinge outside the socket ? 


298 EIGHTH REPORT=1838. 


“7th. Are cast and wrought iron equally well protected ? 

«8th. Has it been tried in fresh water? ss 

“The favour of your replies as early as convenient to these 
queries will be esteemed by us.” 

To which we received the following reply :— 


“ Dock Yard, Liverpool, 27th April, 1838. -_ 
*¢ Sir,—I am in receipt of yours of the 25th instant, the con- . 
tents of which I have communicated to Mr. Hartley, sen., who 
has directed me to inform you, that he has only a small portion 
of the brass left that was attached to the cylinder that first 
caused his attention to the preservative properties of that metal ; 
and with regard to the series of questions put by you, I am de- 
sired to say, that during his son’s absence his other avocations 
are such as not to afford time or opportunity of properly attend- 
ing thereto. 
“Tam, Sir, your obedient servant, 


“ GILBERT CUMMINS. 
“To Mr. Robert Mallet.’ 


We hence were precluded from any information or assistance 
from Mr. Hartley, and were about giving up all hope of expe- 
rimenting on the identical brass stated to have been used at 
Liverpool for protection, when we were unexpectedly favoured 
by Professor Kane with a piece of this brass weighing about 
two pounds, which he stated had been personally handed to him 
by Mr. Jesse Hartley; with these the following selection of 
experiments made by the writer, from amongst many others 
made by Professor Davy and himself, may be stated with their 
results. 

103. When a piece of cast iron was placed in a glass vessel 
of sea water with a piece of this brass laid in close contact with 
its upper side, the iron was rapidly attacked, the brass remain- 
ing bright, and rust soon deposited in large quantity. 

104. An equal sized piece broken from the same specimen of 
cast iron, and exposed in similar circumstances to sea water 
alone, was much less acted upon by it. 

105. Two pieces of wrought iron similarly treated produced 
similar results. 

106. Specimens of cast iron and of wrought iron similarly 
treated, with and without the presence of the brass, produced 
similar results, as above, in fresh water, but more slowly. 

107. Where the surfaces of the brass and iron were in close 
contact, the iron remained nearly bright ; but it did so likewise 
when a piece of plate-glass was substituted for the brass, or 


ACTION OF WATER ON IRON. 299 


when wood, mica, paper, or another piece of the same iron took 
its place. 

108. The larger was the proportion of the brass present to 
the quantity of iron exposed, the faster the latter corroded. 

109. When the brass was attached by solder to the iron, 
whether cast or wrought, the action was the same, with in- 
creased energy, provided the solder (composed of lead and tin) 
Was not immersed in the fluid. When it was, so the results 
were anomalous, corrosion being retarded at first, and after- 
wards accelerated, apparently from a change of electric relation 
between the metals, as in Van Beek’s experiments before 
noticed. 

110. When a cylinder of brass, in composition the same as 
Mr. Hartley’s, was cast round a turned cylinder of wrought iron 
at its fusing temperature, the iron on exposure to sea water was 
rapidly acted upon, and carbonates of lime and magnesia were 
deposited upon the brass, which remained bright. 

111. Corrosion in all cases commenced at the moment of 
immersion, and continued without change for periods of nearly 
two months. 

112. When cast or wrought iron was exposed to sea water or 
fresh in the same vessel with a surface of this brass, but without 
contact, but each communicating by a gold-soldered platina wire 
outside the fluid, corrosion took place of the iron more rapidly 
than when similar pieces were exposed without the presence of 
the brass. 

113. No modification of alloy in the brass within the limits 
of brass or gun metal seemed to produce any very remarkable 
change in the increased rate of corrosion of iron by its presence, 
nor did the results differ materially whether brass proper, viz. 
zinc and copper, were used, or Mr. Hartley’s brass, which is, 
in fact, impure gun metal, or copper and tin. 

114. As the proportion of zinc, however, in the brass in- 
creased, a tendency to preservation should be manifested, and 
conversely as the copper predominated, increased corrosion 
would be expected. This view has suggested a very curious 
branch of investigation now in progress, as to the changes of 
electrical relations to a third metal of definite atomic alloys of 
two other metals, whereof one is in a positive, and the other in 
a negative electrical relation to the former. 

115. These results are sufficient to prove incontestably, that 
brass or gun metal have no protective power over iron what- 
ever, but, on the contrary, greatly promote its corrosion in sea 
or fresh water, and, as we also found, in diluted acids. 

116. But as practical instances often come more home to the 


Wine 


300 EIGHTH REPORT—1838. 


practical man than any experiments made on a small scale, it 
so happens that I am enabled to present an actual instance from 
the Dublin Docks of cast iron deeply acted on and corroded in 
a period of eighteen years, though in close contact with brass. 
This is a portion of a sluice, situated between high and low 
water, made eighteen years since by the firm to which I belong, 
and lately obliged to be removed and replaced with a new one, . 
in company with several others, from the deep corrosion and 
softening it had undergone. 

The brass was here a facing riveted to the cast-iron sluice all 
round, to make it water tight. The composition of this brass 
differs from Mr. Hartley’s only in containing some more zinc, 
of which his contains but a very small quantity, which by ana- 
logy and according to Mr. Hartley’s own view is ail in its fa- 
vour. Here, then, is an experiment of eighteen years’ duration, 
which results in showing that brass has had no protective power 
in the tidal water of the River Liffey. 

117. It appeared worth while to make a quantitative analysis 
of Mr. Hartley’s brass and of this from the Dublin Docks, both 
for the purpose of comparison, and to see if they were atomic 
compounds or mere accidental mixtures with approximations to 
atomic constitution, as is generally the case in brass used for 
engineering purposes, which is produced by remelting. I ac- 
cordingly analyzed a fragment of the first specimen of Mr. Hart- 
ley’s brass, sent us direct from Liverpool, and also of the Dub- 
lin Dock brass, and lastly, that given us by Dr. Kane. The 
method adopted with all was the following, which differs in 
some respects from the modes usually recommended for the 
analysis of brass, and which are incapable of giving results ap- 
proaching correctness. 

Ist. A given weight of brass was dissolved with heat, con- 
tinually agitating in strong nitric acid, which was boiled nearly 
to dryness, diluted with water, and the stannic acid separated, 
washed, ignited, and weighed. 

2nd. The solution and washings evaporated nearly to dryness, 
sulphuric acid added, evaporation continued to dryness, water 
added, and sulphate lead, separated, ignited, and weighed. 

3rd. The solution being acid, treated with sulphuretted hy- 
drogen, and precipitate washed in water impregnated with the 
same ; the CuS—redissolved in aqua regia, with heat, again 
precipitated hot with caustic potass washed with hot water, ig- 
nited, burning filter and weighed. 

4th. The solution and washings concentrated, and pure am- 
monia added in excess, and the Fe,O, separated and weighed. 

5th. Bicarbonate potass added to the filtered solution, boiled 


ACTION OF WATER ON IRON. 301 


briskly to dryness, avoiding spattering, redissolved in water, 
and precipitate of ZnO. separated, ignited, and weighed warm. 
6th. The solution tested for remains of zinc by bihydro-sul- 
phuret ammonia. 
118. 24°80 grains of the brass received from Liverpool through 
Mr. Gilbert Cummins, analyzed in this way, gave the following 
results, reduced to per cent. : 


Tin = 12°012 
Lead = 0°266 
Copper = 79°750 
Bron =) 2" 137 
Zinc = 4°786 
Loss = 0°049 

100-000 


119. 42°085 grains of the brass from the Dublin Docks gave 
the following composition, also reduced to per cent. : 


Tin = 0°807 
Lead = 4°062 
Iron = 0°879 
Copper = 65°890 = 2 atoms Cu 
Ziic = 28'288 = 1 atom Zn 


Luss = 00:074 


100°000 


120. I analyzed 41°705 grains of t!.e specimen of Mr. Hart- 
ley’s brass given us by Dr. Kane, with the follewing results, 
which present a larger amount of loss than I could have wished, 
arising from my having been several times delayed in comple- 
ting the process by unavoidable business.—It gaye, reduced to 
per cent., 


Tin = 4°5294 
Lead = 13'051 
Troms. “=: .1°743 
Zinc = 8:639 
Copper = 67°233 
Loss = 4°810 

100°C00 


It is hence obvious that all these brasses are chance mixtures, 
and that the Dublin Dock brass contains the most zine, and 
comes nearest to atomic constitution; and hence might have 
been expected, on Mr. Hartley’s hypothesis, to have most ef- 


1 iil 


302 EIGHTH REPORT—1838. 


fectually preserved the iron it was in contact with. It is still 
more remarkable, however, how great the discrepancy in consti-. 
tution of the two specimens of Liverpool brags is, the latter 
containing an enormous proportion of lead. 

121. It is not difficult to imagine that the mistake of Mr. 
Hartley has arisen from neglect in observing that which Pro-: 
fessor E. Davy has first pointed out, namely, that iron, or other — 
metals, in its relation to water are preserved from corrosion by 
covering surfaces, although the water insinuates itself between. 
Nor does it appear difficult to account for this result. It would 
appear to be a case of slow or retarded chemical action by the 
opposition of capillary forces of the same class as slow action, 
through Becquerel’s clay plugs or diaphragms, in which, when 
once the first portion of air, combined with the fluid between 
the surfaces in contact, is decomposed and taken up, the chemi- 
cal affinity of the iron, or similar metals, for it, is counteracted 
by the capillarity of the flat tube formed by the opposed sur- 
faces which it is unable to overcome, so as to draw in fresh air 
to the fluid within, already exhausted of it. 

122. Indeed, if Mr. Hartley be reported rightly, he is stated 
to have mentioned that ‘‘soil,”’ mad I suppose, lay on the sluices 
said to have been preserved, and which had to be removed prior 
to their examination; if so, there is little wonder they should 
not have sustained corrosion.— Liverpool Journal. 

123. Another, and an extremely probable reason for the mis- 
take, may have been the supposed preservative surfaces being 
often smeared with oil or grease, which, for a considerable time, 
resists the action of sea or fresh water, and protects the metal 
on which it lies. Indeed, if we could get an air and water-tight 
covering which would remain so, no further protector for im- 
mersed or moistened metals need be sought for. 

124. Accordingly, Mr. Arthur Aikin suggested the applica- 
tion of melted caoutchouc, with or without admixture of oil of 
turpentine, as a varnish to preserve iron and steel, &c., from 
corrosion, so far back as 1821.—Gill’s Tech. Rep. vol. i. p. 55. 
And Dumas has proposed the employment of caoutchouc in so- 
lution as a varnish to the shot and shells in the French arsenals 
(Comptes Rendus, 1836. p. 373); but Payen states that this had 
been tried by the municipality of Grenoble in the year 1834, and 
found useless after a short period. 

125. During the experiments already detailed it seemed just 
possible that Mr. Hartley’s might be yet a concealed case of 
Professor Scheenbein’s anomaly of passive iron, or of Dr. An- 
drew’s inactive bismuth, and the writer was just about com- 
mencing some experiments with a view of elucidating this, when 


ACTION OF WATER ON IRON. 303 


he received the Bibliotheque Universelle, published in February 
last, containing an article by Professor Schcenbein on the very 
subject. In this he shows, as indeed he had previously done ina 
letter to Dr. Faraday in the Lond. & Edinb. Philosophical Maga~ 
zine for December last, that he, Schcenbein, “had already demon- 
strated, Ist. That iron only comports itself passively as the anode 
in relation to the oxygen disengaged by the current in aqueous 
solutions, which contain alone oxygenized compounds, as oxacids, 
oxide, oxysalts, &c.; 2nd. That the state of chemical indifference 
of iron can only be obtained with respect to oxygen; and, 3rd. 
That this metal acts in its ordinary way when it is plunged as an 
anode into aqueous solutions of the hydracids of the chlorides, 
bromides, iodides, fluorides, or sulphurets ; in fact, in solutions 
of combinations whose negative element has a great affinity to 
iron. In these cases the oxygen resulting from the electro-che- 
mical decomposition of the water combines with the iron in the 
same way as the chlorine or iodine disengaged under like cir- 
cumstances. Hence,’’ continues Schoenbein, “as the substances 
which are in solution in sea water are for the most part electro- 
lytes which do not contain oxygen as a constituent, it is impos- 
sible, after the facts above stated, that iron as an anode can be 
indifferent chemically, in relation to sea water ; but, on the con- 
trary, this metal must.combine with the oxygen, chlorine, &c. 
disengaged by the current.” 

Scheenbein then states the result of an experiment he made 
directly with sea water, by plunging an iron wire connected with 
the positive pole of a pile into it, thereby closing the circuit ; no 
oxygen was evolved at the iron, which was oxidized, in strict 
accordance with his general principle. He then proceeds to 
show, that assuming Mr. Hartley’s view to be right, it involves 
an initial absurdity or contradiction in principle; and finally 
concludes, that the observation of Mr. Hartley must be con- 
sidered as doubly anomalous, namely, in relation to common 
and acknowledged electro-chemical laws, and also to those spe- 
cial ones developed by himself. 

126. The anomaly, however, may now be considered simply 
as an error, but one of a very serious character, apparently from 
the extent to which its consequences seem to have been wrought 
out in the application stated to have been made of brass as pro- 
tectors to all the work of the Liverpool Docks, which, unless 
removed, must be attended with the rapid decay and destruc- 
tion of all the iron it is connected with. I have also understood 
that, acting on this presumptive protection, the Liverpool chain- 
cable makers now supply gun-metal pins to their cable shackles, 
at intervals of a few fathoms, by way and under the name of 


304 EIGHTH REPORT—1838. 


** preservers ;”” a more destructive practice can scarcely be con- 
ceived, or one more fatally applied. From these circumstances, 
and lest these mischievous results should be extended elsewhere, 
it has been deemed right thus at length to refute it, which I 
conceive is fully done by Schoenbein’s, Professor Davy’s, and 
my own experiments. 

127. To recur again for a moment to the subject of the boxes . 
of specimens of cast iron sunk for experiment, it was stated 
that they were divided into separate cells for each kind of iron 
by veneers of varnished oak. The reason of this arrangement, 
and a deduction which has grown out of it, and is likely to prove 
important as affording a mode of protecting cast and wrought 
iron, remain to be stated. It having been early remarked that 
the harder irons, whether cast or wrought, were acted on much 
more slowly than the softer and more carbonaceous ones, it 
appeared not impossible that if several different sorts were in- 
closed in electrical continuity in the same box, grave errors 
might be introduced into our results by the iron least acted on 
standing in a negative relation to those more rapidly corroded, 
and increasing the action of the sea or other water upon them, 
and at the same time being themselves preserved to a certain 
extent. 

128. By a few preliminary experiments with the galvano- 
meter, this was found to be a correct view,—it was found that 
of any two different irons, the harder was always in a negative 
relation to the softer, which was positive to it, and hence the 
separation of every specimen became necessary in order to eli~ 
minate this source of error. 

129. This at once suggested to the writer the possibility of 
preserving the hard gray cast iron and the wrought iron, &c., 
in common use, by the application of protectors formed of the 
seftest and most highly carburetted cast iron attainable ; and as 
the conversion of this latter into plumbago, to a great extent, 
did not seem materially to alter its electrical relation to gray or 
white cast iron, or to wrought iron, it seemed probable that it 
might afford an electro-chemical protector superior in many re- 
spects even to zinc. With this view experiments are now in 
progress, and so far are decisively in favour of the method. 

130. The intensity of current produced by soft and hard cast 
iron is much greater than would have been anticipated. When 
two small bars, each 4 in. long, by 0°5 in. wide, by 0°25 thick, 
one of soft black and the other of hard gray cast iron, were both 
broken in two, and an iron wire soldered to each half, on im- 
mersing the two halves of either one piece in common water 
the needle of a Melloni’s galvanometer was scarcely disturbed ; 


ACTION OF WATER ON IRON. 305 


it oscillated about 2°; but when one half of each of the two 
original pieces, i e. the black and the gray, were immersed, the 
needles deviated at once from 78° to 80°, and on adding a single 
drop of hydrochloric acid, flew round. 

131. This action in common water or sea water always showed 
the softer iron positive to the other, and continued constant and 
unchanged in an experiment continued for some days. 

132. When two pieces of cast iron, such as the above, were 
immersed in dilute hydrochloric acid, tied together and in con- 
tact, the harder one remained quite bright and untouched be- 
fore and after the acid was saturated, while the softer was rapidly 
blackened and dissolved ; neither was any gas evolved from the 
negative piece, unless the acid was concentrated. 

133. The subject is not in a state to do more now than state 
the principle in view, and that so far as experiments have yet 
gone, it is likely to add a new if not a better mode of protecting 
iron to those already known; if successful, its application to 
engineering structures will afford many facilities of execution, 
and be attended with much greater economy than any process 
in which zinc is used possibly can. 

134. It already suggests to the engineer the importance of 
preserving uniformity of texture and of chemical composition 
in all parts of his structures of iron, in order that one part may 
not accelerate the destruction of the other. It also shows the 
necessity, when wrought iron (which is negative to all but chilled 
cast iron) is applied in contact with cast iron, of allowing extra 
substance in the latter to meet the increased corrosion produced 
by the wrought iron at the points of contact, and it explains 
why the vital injury is so often sustained in works in cast iron 
of this metal being first eaten away round the bolt holes, as for 
instance, in the air-pumps and condensers of marine engines, 
where the parts of the work are secured together ; and it further 
suggests, that where the sides of these bolt holes in the cast 
iron can be chilled or cast on an iron core, as is often practica- 
ble in such cases, while the bolt will slightly suffer, the cast 
iron round it will be preserved. On a future occasion I hope 
to lay the results of this branch of the investigation before the 
Association. 

135. M. Payen’s observations as to the power of alkaline 
waters to protect iron from rust, though seldom applicable, are 
worthy of further investigation, and an attempt to discover their 
rationale. It has very long been known that lime in powder, or 
limewater, possesses a decided power of this sort, and both are 
in use amongst workmen. 

Cases may be found in practice where solutions of an alkali 


306 EIGHTH REPORT—1838. 


or alkaline earth would be admissible and valuable if found 

effective preservers of iron; for instance, lime-water might 

readily replace the bilge-water in steamers, whose action is at 

present so destructive to the holding-down bolts, blow-off pipes 

and cocks, boiler bottoms, coal bunkers, &c., and to the de- 

composition of which in a great degree the peculiarly offensive 

smell of the bilge-water of steamers is owing. There is no rea-° 
son to assume that dilute lime-water would have any injurious 

action on the timbers of the ship. 

136. Dr. Andrews’ and Scheenbein’s experiments, however, 
in which a metal becomes capable of rendering passive or of 
protecting in certain cases another, although itself not acted 
on, give hope that protectors of this kind may yet be found and 
practically applied to iron ; and hence it is in this direction that 
our efforts should be bent with most energy in seeking to pre- 
serve metals from oxidation, namely, to obtain a mode of elec- 
tro-chemical protection, such that, while the metal shall be 
preserved, the protector shall not be chemically acted on, and 
whose protection shall he invariable. 

137. In illustration of this I may adduce a very interesting 
experiment of Becquerel and Dumas (Comptes Rendus, 6th Feb. 
1837): “ Having taken a flask half filled with distilled water, in 
which was dissolved ;3, of potass, they plunged into it a slip 
of perfectly polished iron, and another of gold; to each was fixed 
a wire of the same metal passing through the cork. The flask 
was sealed with all possible care to prevent the access of air. 
Seyenteen months afterwards the iron preserved all its bril- 
liancy, no tubercles had formed on it, and every thing indicated 
that it had undergone no appreciable alteration.”’ 

When the gold and iron wires were placed in communication 
with a multiplier with a short coil, an immediate deviation of 
35° was produced, and the magnetic needle having oscillated 
awhile, came to rest again at zero. On interrupting and again 
re-establishing the communications 7¢ remained motionless, but 
on leaving the circuit open for a quarter of an hour, and again 
closing it, the needle deviated 25°, and after remaining inter- 
rupted for half an hour, the deviation amounted to 35° again. 

The experiment was repeated, and always with accordant re- 
sults. The current produced is then the result of a discharge 
like that of a Leyden phial. 

Thus, when the iron is in contact with the alkaline water, the 
metal takes by degrees a charge of negative electricity, and the 
water a charge of positive electricity, as if there had been a 
chemical reaction between them. (De la Rive in fact considers 
that it is due to a chemical action, though excessively slow.) 


ACTION OF WATER ON IRON. 807 


These two electricities, notwithstanding their reciprocal attrac- 
tion, remain in equilibrium at the surface of contact, which they 
are not able to break, and they only recombine when we esta- 
blish the communication between the iron and the solution by 
means of a wire of gold or platina. Hence it results that the 
iron rendered constantly negative is found in the least fayoura- 
ble state for combining with the oxygen of the air present in 
the solution. 

' It is unnecessary here to pursue the extract into the rationale 
and objections thereto discussed by the authors, as I merely wish 
to indicate the class of experiments which are the most valua- 
ble as regards our subject. Others very analogous, in which 
anthracite, plumbago, and sesquioxide of manganese are the 
agents, are to be found in Becquerel’s fifth volume of his Fraité 
de I’ Electricité. 

138. The subject, of which I have thus given I fear a very 
imperfect sketch, is a wide and important one, and many care- 
ful experiments are wanting to complete our knowledge of it. 
The following especially are desiderata immediately applicable 
to the engineer and also to the chemist. 

Ist. A series of experiments to determine the rate of pro- 
gression of corrosion in sea water and fresh, at increasing 
depths, from 0 to say 10 fathoms. 

2nd. A comparative series for this reaction at the various 
temperatures of the sea and of rivers, &c. known to be found 
within the the range of our inhabited climates. 

3rd. A determination of the nature and amount of air con- 
tained in sea water at various depths, as recommended by M. 
Biot to the officers of the “ Bonite.”’ 

4th. A set of comparative experiments on the action of sea 
water, diluted with various known proportions of fresh, as at 
the mouths of tidal rivers. 

5th. Experiments are wanting as to the effects of the pre- 
sence of animal matters in a state of putrid fermentation in sea 
and river water, in modifying their action on iron, as in rivers, 
&c. receiving the sewerage of cities. 

6th. Determinations of the amount and nature of the plum- 
bago produced from various makes of iron, its precise compo- 
sition, and the conditions of its heating or not spontaneously, 
with the results of this action. 

A careful repetition of many of the experiments on the action 
of pure water, and of air and water on iron, is also needed, the 
results of former experiments being neither satisfactory nor 
uniform. 


A paper of some novelty on this subject has just appeared in 


308 EIGHTH REPORT—1838. 


the Bibliotheque Universelle for June and July, 1838, by Profes- 
sor Bonsdorf of Helsingfors. In this the author studies in ge- 
neral the action of various metals on air and water, under the 
following conditions :— 

1st. In air perfectly dry and free from carbonic acid. 

2nd. In air saturated with vapour of water, but free from 

carbonic acid. 
3rd. In air containing both the latter. 
4th. In contact with liquid water and air, both free from, and 
also containing carbonic acid. 

He states that in the first condition no metal oxidates but po- 
tassium and sodium. That in the second case no metal oxidates 
but arsenic and lead; in particular, that zinc, iron, and bismuth 
do not oxidate, and that a gentle heat increases the action on 
the first two. The author also brings forward some new views 
on the subject of the deposit of moisture on metallic surfaces in 
certain conditions, which, however, do not seem quite correct. 

7th. Experiments would also be desirable as to whether mag- 
netism affects the rate or form of corrosion of iron, and hence, 
whether position as to meridian has any thing to do with the 
durability of engineering works in iron. 

8th. Experiments upon the suitability of various protecting 
paints and varnishes, and the modes of their application to works 
exposed to air and moisture, would be very valuable, giving pre- 
ference to those which, with other obvious properties, dry soon- 
est after rain, and, under given circumstances, cause the least 
deposit of dew. Upon this point Bonsdorf’s paper above alluded 
to may be consulted. 

9th. A comparative set of experiments would be useful also 
showing, under like circumstances, the effect of corrosion of sea 
water, and of its mechanical abrasion by this fluid in motion, or 
of the difference of action on iron in still sea water and in a tide- 
way. 

10th. It would be exceedingly important also, as an element 
of this investigation, as well as useful to the mechanic, to obtain 
a correct measure of the resistance to abrasion of various makes 
of iron. This has been attempted by Mr. Fairbairn, unsuccess- 
fully, by means of grinding on a stone a piece of weighed iron, 
of given surface and under a given pressure, for a known time, 
and noting the loss of weight. The most likely means of ar- 
riving at this will probably be by making wheels of the various 
irons to be tried, turned on the face and fitted on to steel axles, 
suspending these in a swinging frame, and causing them to re- 
volve for a length of time against the faces of other turned 
wheels, all of one sort of iron, say tyred with No, 1 Welsh bar 


q 


ACTION OF WATER ON IRON. 309 


iron (our standard), and pressed together by known weights. 
The loss of weight sustained by the wheels would then indicate 
their respective ratios of abrasion, the loose axles being, pre- 
viously to weighing, taken out so as to eliminate their wear from 
that of the face of the wheel. 

This method and the probability of its giving correct results 
have been suggested to me by the uniformity with which the 
wheels of railway carriages wear when tyred with the same iron. 
Railway experience also shows that the resistance to abrasion 
in rails of wrought iron is to that of cast iron as 15:4. 
(Wood on Railways.) 

139. In conclusion, I have to regret that my friend Professor 
Davy’s public avocations have hitherto prevented his devoting 
more of his attention and great experimental skill to this sub- 
ject, which, while it has been entrusted to us conjointly, would, 
{ am certain, in his hands have found an abler reporter. 

Our thanks also are due to the several public bodies and pri- 
vate individuals to whose assistance we are indebted in making 
our experiments.—To the Board of Public Works and the Bal- 
last Corporation of the Port of Dublin we are under obligation, 
not only for personal assistance, but for freely placing their 
stores in Kingstown Harbour and the Port of Dublin at our 
disposal. 


Norte. 


Since the foregoing report was sent to press it has been con- 
sidered unnecessary to print the tables of experiments on the 
great scale referred to therein at length in this volume, in as 
much as at present they necessarily consist more of data than 
of results, the latter demanding the lapse of time for their col- 
lection. It has been therefore determined at present merely 
to give a synoptic view of those tables of experiments in 
progress. 

These experimental tables at present contain the following 
data respecting the specimens of iron submitted to trial, viz. 


3 | “4 S ro) Ss Be | : ‘ 
oS I ed og Ma he os o wo a 
2\a g/Se |S8_.|28/2|ES/ES:/3 | Sch | 88 
&o | fod o mee | GR | a) Sa | Se8 |o, | s8e] 2 
Cs | ase | e841 SSS) Ss /o}cun | 8h | le) ess | ace 
— ~~. " Ks 

ie Pens, o28g 28s 22 S o Zea os Moe | Sue 
Zo oo of & is] So MQ |e oO 
| eck] Sa | MeO | Saye] Sh) see |e 5G} eer 
Kip a | Se oo Bo | Se | ges S BES = 
ia) 3S.) Beka pas Be 3 a] as 


The whole series of experiments in progress on the great 
scale is contained in five separate boxes, each containing seve- 
VOL. vil. 1838. x 


310 EIGHTH REPORT—1838. 


ral classes, each of which again consists of numerous individual 
specimens of iron, and are arranged as follows: 

Box, No. I.—Sunk in the clear sea water of Kingstown 
Harbour, and containing :— 

Class, No. 1.—Welsh cast iron. Experiments, No. 1 to 13 
inclusive, 2. e. 13 specimens, different. 

Class, No. 2.—Irish cast irons. Experiments, 14 to 17. 

Class, No. 3.—Staffordshire and Shropshire cast irons. 
Experiments, 18 to 25. 

Class, No. 4.—Scotch cast irons. Experiments, 26 to 57. 

Class, No. 5.—The standard bar of wrought iron. 

Class, No. 6.—Scotch cast iron, cast in green sand, and also 
chilled. 

Class, No. 7.—Welsh cast iron, cast in green sand, and also 
chilled. 

Class, No. 8.—Staffordshire cast iron, cast in green sand, 
and also chilled. 

Class, No. 9.—Irish cast iron, cast in green sand, and also 
chilled. 

Class, No. 10.—Mixed cast irons, various —Scotch and 
Welsh, Irish and Welsh, &c. &c. &c. 

Class, No. 11.—Cast iron used by Messrs. Hodgkinson and 
Fairbairn in their experiments, viz. Scotch, Welsh, Derby- 
shire, Yorkshire, &c. &c. &c. 

Class, No. 12.—Mixed cast iron, suitable for fine finishing 
in machinery, with the “skin” removed entirely by the planing 
machine. 

Class, No. 13.—Hard gray mixed irons, protected by various 
known paints and varnishes, viz. caoutchouc varnish, copal, 
mastic, turpentine, asphaltum, white-lead paint, soft cement 
(wax and tallow), Swedish tar, coal tar laid on hot, drying oil. 

Box, No. IJ.—Sunk in the foul sea water at the mouth of 
the Kingstown sewer. 

Box, No. IIJ.—Sunk in clear sea water, at temperatures 
varying from 115° to 125° Fahr., in the Dublin and Kingstown 
Railway Company’s hot baths at Salt Hill. 

Box, No. [V.—Sunk in the foul water of the river Liffey, 
within the tidal limits, opposite the Poddle river. 

Box, No. V.—Sunk in the fresh water of the river Liffey, 
within the premises of the Royal Hospital, Kilmainham. 

All these boxes, viz. II., III., [V., and V., contain classes 
of specimens co-ordinating with those before stated as con- 
tained in No. I., consisting in all of about one hundred and 
sixty separate and different specimens. 

It is intended to take up these boxes at determinate intervals 


a ~ 


ACTION OF WATER ON IRON. 311 


and examine the reaction which may have taken place; when 
this has been done, it is purposed to give, in addition to the 
‘foregoing data, the following information, with such other in 
addition as may hereafter appear desirable. 

Ist. The weight of each specimen when taken up after an 
interval of twelve months, again after two years, and again, 
perhaps, after a longer period. 

2nd. Loss of weight when cleared from adherent plumbago, 
and weight of the latter when dry. 

3rd. Loss of weight per unit of surface. 

4th. Loss of weight per unit of surface as referred to the 
standard bar as unity. 

5th. Uniformity or otherwise of corrosion and its depth. 

6th. Amount of water absorbed by the iron, if any. 

7th. Chemical properties of the plumbago, e. g. if it ignite 
spontaneously, &c. &c. 

8th. Physical properties of the iron if altered. 

9th. Relative preservative effects of the various varnishes or 
coverings, if any. 

As the giving the information under the second head above 
will obviously render it possible that the reaction on the speci- 
mens may be greater the second and subsequent years than it 
would have been if the plumbago were not removed, means are 
taken to compare the effects of water, &c. on iron in the same 
times and circumstances as above, when the coat of plumbago 
is periodically removed, and when it remains untouched for the 
whole period of experiment. 


5a 


312 EIGHTH REPORT.—1838. 


The following Notice of Experiments on the ultimate Trans- 
verse Strength of Cast Iron made at Arigna Works, Co. 
Leitrim, Ireland, at Messrs. Bramah and Robinson's, 29th 
May, 1837, ts appended to the preceding Report. 


No. of | Mark or Mixture of | Deflection 5 a Ob . 
Exper. Iron used. in ins. 1000. a's servations. 
om 
1 No.1, Arigna pig 0-472 220 
2 No.2, ditto .... 0°555 240 | Maximum strength. 
3 of No. 1, pig. . : 
{ i of No. 2, pig. . \ bore Ao 
4 of No. 1, pig. . : bs 
; { i of old scraps. ; \ Mt see 
4 of No. 2, pig. . 
+ { i of old scraps. . } on ao 
4 of No.1, pig.. 5 
- { 3 of old seraps. . bo 4767 252 
4 of No.2, pig.. : 
7 { 3 of old scraps. . \ sisi! ‘ae 
+ of No.1, pig. . . 
8 { 3 of old seraps. . \ 0384 Lig 
1 of No. 2, pig. . : 
= { 2 of old scraps. ' \ eed \ 192 


Note.—The size of the bars used was 1:5 inch square by 
ft. : in. long. The distance between the supports was 3 ft. 

inch. 

The comparative breaking weights in column the fourth, 
multiplied by 12, will give the absolute weight in pounds which 
broke the bars. 


er 


ON INORGANIC AND ORGANIC SUBSTANCES. 313 


Notice of Experiments in Progress, at the desire of the British 
Association, on the Action of a Heat of 212° Fahr. when 
long continued, on Inorganic and Organic Substances. By 


Rosert Maret, M.R.LA. 


THE original object of these experiments has been to try how 
far it is possible to form many mineral substances which we 
either have not formed in the laboratory, or which have only 
hitherto been produced by the dry method. 

Many circumstances concur with the few scattered experi- 
ments which have been made on this subject in causing us to 
suppose that this may frequently be effected by the long-con- 
tinued action of boiling water or steam, or both, on the consti- 
tuents of the mineral to be formed. 

These may be presented to the action of these agents either 
in a nascent state, as in silex and earths, or oxides recently pre- 
cipitated, without being dried and mixed in the atomic propor- 
tions required to constitute a given mineral if combined; or 
the mineral may be formed by the mutual decomposition and 
recombination of other bodies, more or less difficultly soluble 
in boiling water. Attention has been directed to both methods, 
and indications are not wanting to give hopes of success in 
both. It has been, for instance, some time known, that chal- 
cedony may be formed by the prolonged action of a boiling 
temperature upon gelatinized silica; while, on the other hand, 
it can be equally well formed by the decomposition of certain 
kinds of glass by the same means as remarked by the late Dr. 
Turner. Indeed, the extreme facility with which almost every 
kind of glass decomposes, under the continued action of boil- 
ing water, has greatly retarded these experiments. None has 
been found to answer the purpose but the hard Bohemian 
glass, (which is objectionable in point of expense,) and green 


_ bottle glass; the latter imperfectly. 


The minerals as yet chosen for experiment have been chiefly 
hydrates, of which the following may serve as a type; the 
production of these has been attempted by direct combination 
of their constituents with excess of water. 

Formula adopted. 

Chalcedony or Opal. . . . Sg+HO 

Lenzinite .......A+S+HO 

Miriblapite: c. eRe or Ay Sek 

Cymolite ....... A+8,+HO 

Terre de Reigate. . . . . A+S,+ 


314 EIGHTH REPORT—1838. 


Formula adopted. 
Mesotype ....-- -- 3AS+Na8;+ 2 
Prehnites, o> 0.0.) 2 saeu es aoe AS, Cacao 


2 
Steatite =. ©. SS a 2 Mas, +4 
Chabasie ....+. .. 3AS,+ CaS, +6 
Amalcime “°° 5° oS AS ter oa gE ING EA 
Harmotome. . .... . 4AS8S,4+ BaS,+6 
asillmite’: 9 ees ss OAs ES KO. eee 


Various uniaxal and biaxal micas, and some metallic sulphurets 
and sulpho-salts, have also been attempted by way of double 
decomposition. 

The substances to be tried, when mixed and covered with 
water, are sealed in Bohemian glass tubes, numbered and ex- 
posed to steam in a box between two low-pressure boilers, in 
one or the other of which steam is always up. 

Specimens of peat, of lignin, of coal, and other analogous 
organic bodies, have also been exposed in various ways, in the 
expectation that some light may be thrown upon the formation 
of coal and bitumens; and various supposed insoluble crystal- 
lized native minerals have also been exposed immersed in boiling 
water, in order to determine what its action, if any, may be on 
their crystals, and what effect may result from the dissolved mat- 
ter. Various woods have been placed in contact with gelatinized 
silex and its solutions, in the hope of slowly forming silicifica- 
tions similar to those from Antigua, &c. 

These experiments, it is conceived, will connect themselves 
in a very interesting point of view with those in progress under 
Mr. Vernon Harcourt’s superintendence upon the action of a 
much higher but indefinite temperature upon mineral bodies. 
There is every probability that very many of the minerals in 
the crust of the earth, especially the crystallized ones, have 
been formed at a comparatively low temperature. Quartz is 
daily deposited from the water of the Geysers, and has been 
found in a soft and pasty state elsewhere.—(Beudant Traité.) 
Malachite has been found in a similar state. Vauquelin found 
stalactitic quartz, (Ann. de Chim. xxi.). Crystals of quartz have 
been found in the United States, containing anthracite, and 
one containing a liquid with a piece of coal floating in it; and 
Mr. Haig found hard crystals of quartz in a bottle of Saratoga 
water, which had stood many years, (Quart. Jour. xv.). The 
globules of fluid found in amethyst, chrysoberyl, topaz, fluor 
spar, &c. &c., a fluid found by Dr. Brewster to be volatile at 
75° Fahr., (Edin. Phil. Jour.); the existence of bitumen in 


C000 090 


H 
H 
H 
H 
H 
H 


oe a ee 


—— 


PROGRESS IN SPECIAL RESEARCHES. 315 


basalt, serpentine, greenstone, mica, and many other minerals 
discovered by Mr. Knox (Phil. Jour.), and of fire damp in the 
vesicles of sal gem by Dumas; all these indicate the compa- 
rative low temperature at which the formation of many mine- 
rals has probably proceeded. 

Coal too has been found in Scotland converted into plumbago 
by the proximity of a dyke, yet at such a distance that its com- 
municated heat must have been extremely low. On the other 
hand, facts are not wanting to indicate the powerful effects of 
water and a moderate heat in decomposing and changing or- 
ganic or organized bodies, as, for instance, the changes re- 
marked by Perkins in the oil of his high-pressure steam engine, 
and very many similar known to the organic chemist. 

Again the analytical chemist is familiar with abundant cases 
of the direct combination under favourable circumstances—of 
oxides with oxides, earths with earths, salts with salts, &c., to 
prove the likelihood of minerals being formed by synthesis 
without further decomposition resulting, than loss of consti- 
tutional water; as the combination of alumina and magnesia 
when precipitated together, giving a compound when ignited 
of A/;+ Mg, or colourless spinell, as remarked by Chenevix. 

These scattered facts are sufficient to show that the experi- 
ments here indicated, while they belong to chemistry and mi- 
neralogy, abound in interest to the geologist. The experiments | 
have not been sufficiently long in operation to yield definite re- 


sults. 


Provisional Reports and Notices of Progress in Special Re- 
searches, entrusted to Committees and Individuals. 


PHYSICAL SECTION. 


Professor Forbes contributed a notice of the experiments he 
has been some time prosecuting into the Temperature of the 
Earth at different depths, and in different sorts of rock. The 
results will be laid before a future meeting of the Association. 

Sir J. Robison and Mr. J. S. Russell reported the progress 
of their investigations on Waves. As this subject has been 
again entrusted to the further examination of the Committee, 
it is thought proper to defer the publication of the results already 
obtained till the Committee shall present their complete report. 

‘Mr. Baily reported that the Committee appointed to repre- 
sent to government the importance of reducing the Greenwich 
observations of the moon, had waited on the Chancellor of the 
Exchequer, and that the sum of 2000/. had been appropriated 


316 EIGHTH REPORT—1838. 


for that purpose, which was placed at the disposal of the As- 
tronomer Royal, who had undertaken to superintend the re- 
ductions. z 

Mr. Baily reported that the reduction of the stars intended to 
form the enlarged Catalogue of the Royal Astronomical Society 
was in progress; that a small portion only of the original sum 
appropriated had been expended ; but that, in all probability, - 
the whole would be required in the course of the ensuing year. 

Mr. Baily reported that the reduction of the stars in the His- 
toire Céleste, &c., was in progress ; that a small portion only of 
the sum appropriated had at present been expended; but that 
about half the amount would be required. 

Mr. Baily added, that he had made repeated application to 
the Secretary of the Bureau des Longitudes for the corrected 
copy of the Histoire Céleste gratuitously offered by that Board 
for the use of the computers ; but that he had not yet received 
any answer to such applications. 


Report of the Committee for the Liverpool Observatory. 


The Committee, after carefully examining the local circum- 
stances of the port of Liverpool, and arranging the plan which 
seemed most expedient for the establishment of an Observatory 
at Liverpool, laid it before the local authorities, who approved 
of the proposed arrangement, and expressed their readiness to 
carry it into effect as soon as the necessary powers could be 
obtained from Parliament. 


CHEMICAL SECTION. 


Apparatus for the Detection and Measurement of Gases pre- 
sent in minute quantity in Atmospheric Air. By Wu. WEstT. 


Mr. West produced and reported verbally upon his apparatus 
for the above purpose, for the construction of which the Asso- 
ciation had, in a former year, voted the sum of 20/. By the ac- 
tion of a spiral spring in front of the drum or cylinder of Cros- 
ley’s gasometer, a partial vacuum is produced, to fill which the 
air presses from without, and in its passage is conducted through 
several two-necked bottles filled with liquids fitted to combine 
with and detain the gases sought, as lime-water for carbonic 
acid, &c. The same gasometer registers the quantity of air 
thus deprived of the accidental and variable gas, while the 
quantity of gas separated is found by calculation from the pre- 
cipitate formed in the bottles. The apparatus had been con- 


PROGRESS IN SPECIAL RESEARCHES. 317 


structed too recently to admit of any results being obtained 
beyond preliminary trials, which promised well, both as to effi- 
ciency and accuracy. 


Information was furnished of the progress made by Professor 
Liebig in the preparation of his report on Organic Analysis. 

Professor Johnston read a preliminary report on Inorganic 
Analysis. 


GroLocy AnD GroGrapny. 
The progress made by M. Agassiz in developing the Fossil 
Ichthyology of Great Britain was stated. 


Natura Hisrory. 

Sir W. Jardine, Bart., presented a report on the Salmonidz of 
Scotland, and expressed his desire to continue the investiga- 
tion. The full report will consequently appear hereafter. 

Mr. Gray communicated a preliminary notice on the subject 
of the Perforation of Rocks by Mollusca. 

Mr. Jenyns stated, that the Committee on preserving animal 
and vegetable substances in a moist state were in operation. 

The commencement of Mr. Gould’s Essay on the Caprimul- 
gidze was communicated. 

Mr. Vigors stated, that considerable progress had been made 
by the Committee on the Irish Fauna. 


MEDICAL ScIENCE. 

The London Committee on the Sounds of the Heart stated 
the circumstances which prevented the preparation of their re- 
port, and announced that it will be ready at the meeting in 1839. 

“The Committee have been engaged almost daily for several 
hours during the months of June and July, in prosecuting the 
researches for which they were appointed, and have obtained 
many interesting results, particularly in relation to the sounds 
of the heart and arteries as signs of disease. These results were 
to be presented at the present Meeting of the Association; but 
the death of a colleague having prevented the member who was 
to draw up the report from completing it, the Committee are 
obliged to postpone it to the next meeting, when they trust 
that it will be made still more worthy of the attention of the 
Medical Section of the British Association.” 

_ Dr. Williams expressed his hope of being able to present a 
report on the Physiology of the Lungs and Bronchi in 1839. 
VOL. VII. 1838. Y 


318 EIGHTH REPORT—1838. 


Dr. Carson stated, that owing to the small number of cases 
of lung disease in animals which had occurred in-the Zoological 
Gardens of Liverpool in the winter of 1837-8, the Committee 
on that subject had not been enabled to make a report to the 
Newcastle Meeting, but intended to do so at the Birmingham 
Meeting. ) 


Appendix to a Report on the Variations of the Magnetic In- 
tensity (printed in vol. vi.). By Major E, Sainz, F.RS., 


Se. 


In reference to the report on the Variations of the Magnetic 
Intensity, which the British Association have done me the ho- 
nour to print in their last volume, I wish to communicate the 
results of the observations made by Captain Duperrey in his 
voyage of circumnavigation in the Coquille, in 1822—1825, 
which I have received in a private communication from that 
distinguished officer and magnetic observer. The Section will 
learn with pleasure the satisfactory accord of these observa- 
tions with those of Captains De Freycinet and Fitz Roy, pub- 
lished in my report. When in compliance with the wishes of 
the Association, I first entertained the purpose of collecting in 
one body the observations of intensity made by different ob- 
servers in all parts of the globe, so far as they are comparable 
with each other, one of my first steps was to write to Captain 
Duperrey to solicit the communication of any intensity results 
which he might have obtained. I find, by the letter which I 
have received, that Captain Duperrey did kindly comply with 
my request; but, unfortunately, the packet which must have 
contained the particulars of his observations has never reached 
me. The letter which I have received contains a notice, both 
of the results he obtained, and of the mode in which they were 
observed. Had I possessed this information at the time my 
report was printed, I should on every account have rejoiced to 
have embodied it in the report: and I am anxious to avail my- 
self of this opportunity of doing what may yet be done to sup- 
ply the omission. Captain Duperrey’s observations were made 
with a horizontal needle, which, from accidental circumstances, 
was not observed with prior to his departure from France. 
The usual test of the permanency of the magnetism of the 
needle, viz. its vibration at the same station, at the commence- 
ment and at the close of the series, was, therefore, omitted in 
this case. In the absence of this, which is the most conclusive 
test, Captain Duperrey has estimated the loss which his needle 


VARIATIONS OF THE MAGNETIC INTENSITY. 319 


may have sustained, by comparing its rate of vibration at Paris 
on his return, with its rate at a station in Peru, in the line of 
no dip, in which comparison he has assumed the relation of the 
force at that station to the force ai Paris to be as 1 to 1:3482. 
The loss of magnetism sustained by the needle on this estima- 
tion was altogether inconsiderable. The times of vibration at 
four other stations at which this needle was employed, cor- 
rected for temperature and arc, give the following values of 
the total intensity. 


Payiaeosoo.. 5° 6S... 278°50E. . . | 1-024 
ia sas Oe eS  DAO 4a  O79 
Port Jackson..,33. 52) 4 6 15b12 . 1617 
Isle of France «.: 295) Disomd icbRBLS YS Oo ISI 


These determinations are inserted in a map engraved in 1832, 
referred to in a paper read by M. Duperrey to the Academy 
of Sciences at Paris in 1833, entitled, ‘‘ Considérations sur le 
Magnetisme Terrestre.” Captain Duperrey notices, that at two 
other stations, viz. Talcahuano and St. Catherine’s, he observed 
the times of vibration of a dipping needle, the poles of which 
were reversed at each station, in the usual manner, for the ob- 
servation of the dip; and that the results derived from the vi- 
bration of this needle, presuming it to have received, on every 
occasion when the poles were changed, an equal magnetic 
charge, correspond in a remarkable manner—as indeed they 
do,—with the subsequent observations of Captains King and 
Lutke; but Captain Duperrey, of course, attaches to these 
determinations no independent value, and therefore I need not 
notice them further. Captain Duperrey has also communicated 
to me three results obtained at stations in France in 1834, with 
one of M. Hansteen’s needles, made, as it appears, with very 
great care, and with every necessary precaution. These re- 
sults are, for 
Lat. Long. W. Paris. 

resin ait. PAR 2a G50 * oo 1865 

Wandevenvers® (45:18). 6°35... 1363 

Orleans). Oe Uaioe O-26--. Bd 


I may take this opportunity also of adverting to the observa- 
tions of Professor Bache and other gentlemen of the United 
States, which were not included in my report. These obser- 
vations were made at New York, and in the adjoining states; 
and Mr. Bache is now engaged in connecting them with Eu- 
rope, and, consequently, with the general body of the intensity 
observations. Until this comparison is complete, which it will 
not be until Mr. Bache returns to the United States, the ob- 


aa 


320 EIGHTH REPORT—1838. 


servations referred to serve to determine the value of the mag- 
netic force at the stations at which they are made, relatively to 
each other, but not relatively to other parts of the globe; and 
they were not, therefore, available for my report. The Ame- 
rican observations were made with magnetic needles inclosed 
in a vacuum apparatus, which Mr. Bache had devised, with the » 
view of avoiding some of the anomalies occasionally experienced 
by other observers. They were made with extreme care, and 
were remarkable for minute attention to all those circumstances 
which conduce to the accuracy of the results. 


END OF THE REPORTS. 


of 


NOTICES 
AND 
ABSTRACTS OF COMMUNICATIONS 
10 THE 


BRITISH ASSOCIATION 


FOR THE 
ADVANCEMENT OF SCIENCE, 
AT THE 


NEWCASTLE MEETING, AUGUST, 1838. 


ADVERTISEMENT. 


Tue Epirors of the following Notices consider themselves responsible 


only for the fidelity with which the views of the Authors are abs- — 


tracted. 


Pa 


CONTENTS. 


aa 


NOTICES AND ABSTRACTS OF MISCELLANEOUS 


COMMUNICATIONS TO THE SECTIONS. 
MATHEMATICS AND PHYSICS. 


Page 
Mr. Cuarues Graves on a General Geometric Method ..........s.ssseeeeees “i 
Sir W. R. Hamixton on the Propagation of Light i vacuo ........sesesevece 2 
Sir W. R. Hamixton on the Propagation of Light in Crystals ............ fawn 
Professor Powett on some Points connected with the Theory of Light.... 6 
Sir D. Brewster on an Ocular Parallax in Vision, and on the Law of Vi- 
sible Direction ...... Ue ea Uy koe SARL SN co Olea es ca bab asawetc anil 7 
Sir D. Brewster on a New Phenomenon of Colour in certain specimens 
OL HUGS Paley weiss asia diets sianeae an ctenlenehine clea. ules a antesiels an eerena= san 10 
Sir D. Brewsrer’s Account of certain New Phenomena of Diffraction.... 12 
Sir D. Brewsrer’s Account of an Analogous Series of New Phenomena of 
Diffraction when produced by a Transparent Diffracting Body........... « lz 
Sir D. Brewster on the Combined Action of Grooved Metallic and Trans- 
parent Surfaces upon Light .........sscsscosenecnseccsnenecsssacscsscssnceecsons 13 
Sir D. Brewster on a new kind of Polarity in Homogeneous Light ...... 13 
Sir D. Brewster on some Preparations of the Eye by Mr. Clay Wallace, 
of New York ......0c0.06 Patents ne eeselele eissitaln sfeia aplalsaiotsatbeleite Ses sinless aeitaeeasited sis sos 14 
Sir J. F. W. Herscuex on the Structure of the Vitreous Humour of the 
[Dive 8a) SMES <a /ioan 45 --onnua- Pare RO ne, SERA cennnobe -adeeranineoe doce riper sosoes 15 
Professor Wuratstone on Binocular Vision; and on the Stereoscope, an 
instrument for illustrating its phenomena. ............sccesesevescsresececoeces 16 
Sir Joun F. W. Herscuex’s Observations on Stars and Nebule at the Cape 
Pol Good, MOpelh <secsdetedhds suse sanitivaesidetsen aries suhanedeaieencnkenadannacseaa 17 
Sir Joun F. W. Herscuer on Halley’s Comet ..........cccsecececsccecsceceres 19 
Sir Tuomas M. Briszane on the Difference of Longitude between London 
and Edinburgh........ {or eeande in aaae dee or nating nose GaP ora ce no pecube ApecconsGe oe . 20 
Mr. G. B. Arry on the means 1s adopted for ‘correcting the Local Magnetic 
Action of the Compass in Iron Steam-ships .........+.. me daats eaiaeiamnion iste te 21 
Lieut.-Colonel Rrrp’s Statement of the Progress made towards developing 
the Law of Storms; and of what seems further desirable to be done, to 
advance our knowledge of the subject ......scsssecssecsesssecseeseeseverseens 21 
Professor A. D. Bacun’s Note on the Effect of Deflected Currents of Air 
on the Quantity of Rain collected by a Rain-gauge .........+sseseeseereee 25 
Dr. Wittram Sir on the Variations in the pee of Rain which falls 
in different Parts of the Earth............ meet eae soles oeidale staamidastenieider as sake 27 
Professor Forzes’s Notice of a Brine Spring emitting Carbonic Acid Gas.. 28 
Dr. Dauseny on the Climate of North America............ eodwectaneeamanaes 29 
Rev. J. Watson on the Helm Wind of Crossfell ............0sessseesessecsens 33 
Mr. Hopexinson on the Temperatures observed in certain MinesinCheshire 34 
Mr. Dent’s Facts relating to the Effects of Temperature on the Regulators 
of ‘Time-keepers; and description of some recent improvements in Pen- 
dulums, with Observations, and Tabulated Experiments ...... an ccewer oe 35 
Sir Joun Rosison’s Notice of a cheap and portable Barometrical Instru- 
ment proposed for the use of Travellers in Mountainous Districts ...... 37 
The Rev. Professor Tempte Cuevaiier’s Tables intended to facilitate the 
computation of Heights by the Barometer ........ dedsiae agi ego go.mer ae eladaee 38 
a2 


iv CONTENTS. 
CHEMISTRY. = 
Page 

Extracts from a Letter addressed by Dr. Hare to the Chemical Section 

of the British Association for the Advancement of Science ...........0+0 
Dr. Tuomas Tuomson’s Observations on the Foreign Substances in Iron.. 41 
Dr. Tuomas Tuomson on the Sugar in Urine of Diabetes.............s0ses00 43 . 
Dr. THomas THOMSON On Galaetin .........ceccssccscee seccscerecsccncecscseceecs 46 
Dr. Tuomas Tuomson’s Notice respecting the native Diarseniate of Lead... 46 
Dr. T. Tuomson and Mr. T. Ricuarpson on Emulsin ...........eseeseeeeeeees 48 
Mr. Tuomas Ricuarpson’s Examination of Sphene .........:ssececseveeeeeeee 49 
Mr. H. L. Parrinson on a New Process for the Extraction of Silver from 

Lia « cvapesnvevedeentemetae tee erakiigs coe «vineliansalton couse ante ce tee eed Rae ameear 50 
Dr. Gotprne Brrp’s Observations on some of the Products obtained by the 

Action of Nitric Acid on Alcohol .........ssscseceseeececercnsnseensuseseeneeees 55 
Dr. Gotpine Brrn’s Notice respecting the Artificial Formation of a Basic 

Chloride of Copper bysVoltate: Influence. .i.o010.6: sieves 04 ates ovevtassctenweed 56 


Dr. Gotpine Brrp's Notice respecting the Deposition of Metallic Copper 
from its Solutions by slow Voltaic Action at a point equidistant from 
the Metallic Surfaces! Uevacsorsere-seresticavaeestece css verectsteceou tennee deena 57 
Professor Jounston on a new Compound of Sulphate of Lime with Water 59 
Professor Jounston on a new Compound of Bicyanide with Binoxide of 
Mercury csccecesscereceecsonsccsscaccscescecscecceesesccesseesesessecsseseacseese 59 
Prof. Jounston on some “supposed Exceptions to the Law of Isomorphism 59 
Professor Jonnston on the Origin of Petroleum, and on the Nature of 


the Petroleum from Whitehaven.....cccsccscsscccevccccvcccssccsesccssccccccess 60 
Professor Jounston on Middletonite and some other Mineral Substances 

Of Organic Origin.......sssssessccssscrecccsccsesceecscescuaesanscseuccecceseseoes 60 
Professor Jounston on the Resin of Gamboge (Gambodie Acid) and its 

Compounds ......ssssesecsessssessnccesscecscccnccaeceuessesaceueeseeseeeseuesee Feo 60 
Mr. R. Puitiies on a Blue PISMENGM aeevetseereaater és «cls aeaveer start secnsccer 00 
Mr. C. T. Coaruursz on the Blue Pigment of Dr. Traill.. woalajorewe seed Fo asidee ne 61 
Mr. R. Matter on a new case of the Chemical Action of Light in the Déeos 

loration of Recent Solutions of Caustic Potass of Commerce......... aieeten Ok 
Mr. Scanuan’s Observations on the Constitution of the Commercial Carbo- 

MateloLMATNMOMNIats dices ceces sec cuoes ohodc ces vaciesenueceescaseeatereemnseeeals assed’ 68 
Mr. Scanzan on the Blackening of Nitrate of Silver by Light..............+ 63 


Rev. T. Extey on the Specific Gravities of Nitrogen, Oxygen, Hydrogen, 
and Chlorine; and also of the Vapours of Carbon, a ele pin” 


and Phosphorus ....+..csesceceecesseseceeseeseseens edivicuw ardent enocs svssueactene 64 
Rev. T. Extey on Chemical Combinations ‘produced i in virtue of the pre- 
sence of other bodies which still remain .......ssesseceeeseeerecsserseeseecees 68 


Mr. Joun Samuet Dawes on an Improvement i in the Manufacture of Iron, 
by the Application of Gas obtained from the decomposition of Water... 68 
Dr. Anprews on the Influence of Voltaic Combination on Chemical Action 69 
Mr. Rosert Appams on the Construction of Apparatus for solidifying Car- 
bonic Acid, and on the elastic Force of Carbonic Acid Gas in contact 


with the liquid form of the Acid, at different Temperatures..........++006 70 
Mr. Witi1aAm HerapatuH on a New Process for Tanning........scsecceeeees 71 
Mr. Wittr1am West on some New Salts of Mercury .........sseceeseereeeeeene 72 


Mr. Wittram Mauenam on a New Compound of Carbon and Hydrogen.. 72 

Mr. Witt1am Maveuam on a Mode of obtaining an Increase of Atmo- 
spheric Pressure, and on an Attempt to liquefy Hydrogen and Oxygen 
Gases, with accompanying ApparatuS.........s.cccsceeceeeeeecenes eee Oe « 73 

Mr. Joun Murray on the Water of the Dead Sea......... pevececccccavesves 73 


CONTENTS. Vv 
Page 
Lieut. Morrison’s Observations and Experiments made upon an Instru- 
ment termed a Magnet-Electrometer ........sesesssosscsseecesnseveneesreneces 74 
Mr. Tuos. E. Buackwatt on the Production of Crystals of Silver............ 74 
GEOLOGY. 
Mr. Joun Buppte’s Observations on the Newcastle Coal-field.............+. 74 
Mr. D. Mixye on the Berwick and North Durham Coal Fields............... 76 
Mr. Nicuoxtas Woop on the Red Sandstone of the Tweed and Carlisle...... 78 
Mr. H.'T. M. Witruam’s Account of Rolled Stones found in the main Coal 
Seam of Cockfield Fell Colliery .........:.:scscsssecescsescncseesaececseceneens 79 
Mr. T. Sopwirn on Sections of the Mountain Limestone Formation in 
Alston Moor, exhibiting the general uniformity of the several beds...... 79 
Mr. J. B. Juxzs on the Position of the Rocks along the South Boundary of 
the Penine Chain ...........cscseceeevees Sonpse) 500 sAbgomaadcaseobodee: sevsdseccwes //fG 
Mr. R.I. Murcutson on the Silurian System of Strata .............0.000e - 80 
Mr. R. Grirritx on the Geological Structure of the South of Ireland .... 81 
Capt. Portiocx on a small Tract of Silurian Rocks in the County of Tyrone 84 
Account of the Footsteps of the Cheirotherium and five or six smaller Ani- 
mals in the Stone Quarries of Storeton Hill, near Liverpool, communi- 
cated by the Natural History of Liverpool.............sesesee0e Ketaeopobosee oe 85 
Mr. Oram on a Plan of cementing together Small Coal and Coal Dust for 
Fuel .........0006 Higa) GogbhinodSne So-thiSaE donee nnist doa saHaos cain adanannarHoasrndociaec 85 
Mr. Lone’s Description of a Cave at Cheddar, Somersetshire, in which Hu- 
man as well as Animal Bones have been lately found .............eceeeee. 85 
Mr. Josuua Triwmer on the Discovery of the Northern or Diluvial Drift 
containing I'ragments of Marine Shells covering the remains of Terres- 
trial Mammalia in Cefin Cave .........scceccccsscsenscscascscoscnseecescscescees 86 
Mr. James Smiru on the Shells of the Newer Pleiocene Deposits .......... 87 
Mr. C. Lyext on Vertical Lines of Flint, traversing Horizontal Strata of 
Chalk, near Norwich .............. REDE OAH oQgoE SORE aCBee Dotesuccstocacemtnede 87 
Mr. Joun Lerruart on the Stratification of Rocks ...... SMB sopacdsonbeneaen 88 
Mr. Joun Leiruarr on Faults, and Anticlinal and Synclinal Axes......... 89 
Mr. Rosert Were Fox on the Production of a Horizontal Vein of Carbo- 
nate of Zinc by means of Voltaic Agency ...........-scseceessesseesceceececs 90 
Sir D. Brewster on the Structure of the Fossil Teeth of the Sauroid Fishes 90 
Dr. Dauzeny on the Geology and Thermal Springs of North America ... 91 
Mr. Ausren’s Considerations on Geological Evidence and Inferences...... 93 
Mr. T. W. Wess on Lunar Volcanos .........scsscsecsesecescterees SensiisnscsSers 93 
Mr. Tuomas Sorwirn on the Construction of Geological Models......... oe 94 
Rey. G. Youne on the Antiquity of Organic Remains ..........sscesseseeenes 95 
Dr. G. H. Adams on Peat Bogs .........s..seeeeseeee sHdonssceebasbenpacrshecco ne 95 
GEOGRAPHY. 
Professor Von Barr’s Recent Intelligence on the Frozen Soil of Siberia... 6 
Prof. Barr’s Sketch of the recent Russian lxpeditions to Novaia Zemlia.. 96 
Captain Wasuineton’s brief Account of a Mandingo, native of Nyani- 
Mari, on the River Gambia, in Western Africa ......ccs.ccecsesesecececes 97 
Captain WasuincTon on the recent Expeditions to the Antarctic Seas ... 97 
Captain Wasuincton’s Summary Account of the various Government 
Surveys in Europe, illustrated by specimens of the Maps of England, 
France, Austria, Saxony, Tuscany, &c. &¢. .........cecccseseccceseceescsees 98 
Lieut.-Col. VeLasquez pz Leon on the recent Government Map of Mexico 98 


Major Jervis’s Sketch of the Progress and Present State of the Trigono- 
metrical Survey in India 


vi CONTENTS. 


Page 
Captain W. Aten on the Construction of a Map of the Western portion 
of Central Africa, showing the probability of the River Tchadda being 


the outlet, ofthe Waake! Pchad ); 20, Aes fives il eseedesidecersa vatwlececessecvesbee 99 
Mr. J. B. Pentuanp on the recently-determined Position of the City of 

GEZCOME PEL, Sacnccsccucdaccccoeencachenasbens arascnasesumetccarnecen cre acsscetame 99 
Lieutenant Lyncu on the recent Ascent of the River Euphrates ............ 99 

ZOOLOGY. 

Mr. J. Hinpmarsu on the Wild Cattle of Chillingham Park .............. . 100 
Lieut.-Colonel Syxes on a rare Animal from South America ............ ee. 104 
Rey. L. Jenyns on certain Species of Sorex ........sscseeceeeres ApEARGSO HE Oke 104 
Professor OWEN on Marsupiata ..sccccesscescereceeeecenceeece ence deko etch . 105 
Dr dé Ricmanpsonponeeoucheu cl ats. ..acc ces acacscwavecsteescnsesccscucnaeseniee 105 
Mr. Joun Hancocx’s Remarks on the Greenland and Iceland Falcons .,. 106 
Mr. Artuur STrickbANnD on the Ardea Alba........cecscceeseccecccecenssnesees 106 


Mr. A. SrricKLanp on a species of Scyllium taken on the Yorkshire Coast 107 
Mr. T. Actis on the Toes of the African Ostrich, and the Number of Pha- 


langes in the Toes of other Birds...........sesseeeeeseeeeeeseecneeas tescecwence 107 
Dr. Epwarp Cuaruton on Tetrao Rakelhahn .........ccsecescceeccceccetcecce 107 
Mr. Evwarp Bacxnouss, Notice of the Annual Appearance on the Durham 

Coast ofisome of the Lestris tribe. scccccuctacecessacsascenessascenaescesenewepa 108 
Mr. W. Yarrett on a New Species of Smelt from the Isle of Bute......... 108 
Dr. Ricnarp PARNELL on some new and rare British Fishes ............0.. 109 


Dr. P. D. Hanpysrb£ on the Sternoptixinez, a family of Osseous Fishes... 110 
Messrs. W. H. Cuarxe and Joun Mortimer on a Fish with Four Eyes... 110 


Mr. J. E. Gray on a new British Shell ....... ene cesediesbascasscaresveaeeauaanes 110 
Mr. J. E. Gray on the Formation of Angular ipties on vie Shells oF cer- 

tain Mollusca. Ee re ene arene cGiachne cas ciaenarn es dotcom dccowacs eh ceiee anneateeeneeeee 11 
Mr. J. E. Gray’s Notice of the Wombat..........ssccsecescconscecs secctescnesaat 111 
Mr. J. E. Gray on the Boring of Pholades...........cscessecseoecececeecsceences 111 
Mr. E. Forses on the Distribution of Terrestrial Pulmonifera in Europe... 112 
Rey. F. W. Horr’s Remarks on the Modern Classification of Insects ...... 113 
Rev. F. W. Hope on the Noxious Insects which have this year (1838) se- 

riously injured the Apple Trees and Hops ......ssscssessesseseseeeeeenceeees 113 
Mr. J. A. Turner on a new Species of Goliathus and some Lucani, from 

the GoastiotsA fica Menack cous ne ceenck acces sees decnscnecadce sete sasedaeeCumeatysnne 113 
Mr. T. P. Teave on the Gemmiferous Bodies and Vermiform Filaments of 

DA CLIN EEO eee rasa sue uc ocetees sa cesdadde!aesnue sect cecemsoctsanscsauanenndaaraVanceuavesl 113 
Mr. G. B. Sowrersy on certain Monstrosities of the Genus Encrinus ...... 115 
Professor EnRENBERG’s Notice of Microscopical Discoveries............+08+- 116 

BOTANY. 

Professor Morren on the Production of Vanilla in Europe ............000008 116 
Mr. Cuartes C. Bazineton on the Botany of the Channel Islands ........ nila 
Capt. J. C. Coox on the Genera Pinus and Abies ..........0.c0cscscccscccentons 117 
Mr. G. B. Sowersy on Lycopodium Lepidophyllum...............scseeeeeeee 119 
Rev. W. Hincks on Vegetable IVIGN SELOSIUIEN es -acsnenoadecneast maser sons seers 120 
Mr. Wattacs’s Account of an Inosculation observed in two Trees ......... 120 


MEDICAL SCIENCE. 


Dr. Bownine’s Gbservations on Plague and Quarantine, made during a 


TERM CHO 1 PRB MLATE cy. iddisceines -picemndthes eokseedaseRe  snmeb ccikneonindnnnai’ ainda 120 
Mr. Goopsir on the Origin and subsequent Development of the Human 


Meethise. «creas colada piecee aa ace de uc cae a GUase emaraalsteeb a albtembiscls alaials aluteraielara et aale sateen 121 


: 


CONTENTS. 


Dr. Spirrau’s Experiments and Observations on the Cause of the Sounds of 
RANG fo vevieleeiny viubiaat Wescsidehia saw aus ddA Gee ka abas havand schbe(beieeliudes 
Dr. A. T. Tuomson on the Medicinal and Poisonous Properties of some of 
the Iodides 


POOP e aT EERE ERE He SHEESH EOE HEED ESE EE EEE OEE EE HEE SOE EEESEE ESE EEEreene 


eee eee ee eee ee ee ee er rs 


oe Teer e eer errr rrr rry Peereecaceeeses eee 


Dr. Crawrorp on a Case of Anthracosis in a Lead Miner 


Cee esoccercssesessccsees eee 


meseoevce 


Fee em eee seat seers as eeseeneseee 


Page 


122 


133 
134 
134 


135 


150 


150 
152 


153 
154 
154 
154 
155 


156 


156 
157 


viii CONTENTS. 
Page 
Mr. T. Mottey on a Suspension Bridge over the Avon, Tiverton............ 157 
Mr. J. Price on an Improved Method of constructing Railways ....sccceeee 158 
Mr. Hatt’s Machine for raising Water by an Hydraulic Belt ...... couslenane 158 
Mr. Samupa on Cliff’s Dry Gas Meter.......ssssseseesssecseesseeeeees ssc tence «. 158 
Mr. Joseru Garnett on anew Day and Night Telegraph .. vs woe edo 
Mr. Hawrnorn on an Improved Method of working the Valves of a Loco- 
motive Engine ...... sacratiuecusddesedvecedas died cddeddsceatedeaddchiclsic cover emer: 160- 
Mr. W. Fairzaren on the Application of Machinery to the Manufacture of 
Steam-Engine Boilers, and other Vessels of Wrought Iron or Copper, 
subject to Pressure ...cccssesee seecsccscceerecescscencescees sunseeseessesesansce 160 
Mr. J. Price on a Steam-engine Boiler .......csececsseoscsssecececeeceesens cbiatiod 162 
Mr. S. Rowzey’s New Rotatory Steam-Engine ..............+ Uestesep ees seceee 162 
Mr. W. Greener’s Remarks on the Consiruction of Steam-Boilers...... .-. 162 
Mr. Mavte on a Substitute for the Forcing Pump in supplying Steam- 
Boilers eace teresa temetecdenatc estes saceadeesests odiac hoe senesmecdereNescm w. 163 
Mr. Joun Scorr Russetx’s Notices on the Resistance of ‘Water’ <.:.cscscse. 163 
Mr. J. T. Hawxrys on Methods of Filtering Water ............ Baccacenoncace 163 
Mr. Dosson on a Method of making Bricks of any required Colour......... 163 
Mr. Fourness on Coal-Mine Ventilation............sesescseessserececesseveeees .. 163 
Mr. JosepH Guynn on the Water-works of Newcastle-on-Tyne .........4.. 164 
STATISTICS. 
Mr. Carcitt on Educational Statistics of Newcastle..........sseceeeesseeenee 165 
Mr. D. H. Witson on the Church and apes ees in All Saints’ Parish, 
Newcastle --sccsrsssssassecceseseptcedasenecs)isarcvencasp¢-ncoms -ssuessanamsdieaee 166 
Mr. Joun Steruens’s Return of Prisoners coming under the cognizance 
of the Police in Newcastle, from the 2nd of October, 1837, to the 2nd 
Of August, 1838 .icscceccosecereneenscceccnscussencsonseeceseseseusessceneoners 166 
Rev. J. M‘AtisteEr’s Statistical Notices of the Asylum for the Blind lately 
established at Newcastle-upon-Tyne .....cecececsesesceesserecevassenees .» 167 
Mr. Hinpmarsu on the State of Agriculture and the condition of the Agri- 
cultural Labourers of the Northern Division of Northumberland......... 167 
Mr. W. H. Cuartron’s Statistical Report of the Parish of Bellingham in 
Northumberland ..........scceseecccsesceesssseeeees aseeeeasnaeustie Sonennaen a 168 
Mr. P. M‘Dowat on the Statistics of Ramsbottom: \s..cvssscesoceveuescabee 168 
Mr. W. L. Wuarron’s Statistical Tables of the Engines, Ventilation, 
Screens, Sales, &c.; and Pitmen; and the Strata of Nine principal 
Collieries in the County of Durham : the first eight being situated on the 
East or “ Dip” Side of the great Durham Coal-field ...........sseeseseseees 169 
Rev. H. L. Jones’s Series of Statistical Illustrations of the principal Uni- 
versities of Great Britain and Ireland .........scsessececscececececececeeacecees 170 
Mr, W. R. Rawson’s Description of the “ London Fire Engine Establish- 
ment,” and of the Number, Extent, and Causes of the Fires in the Me- 
tropolis and its Vicinity, during the Five Years from 1833 to 1837...... 170 
Mr. Kawson’s Abstract of Report of the Railway Commissioners of Ireland 171 
Mr. W. Fexxrn’s Abstract of Statistics respecting the Working Classes in 
Hyde, Cheshire.........scossessssceevevesreenescsseneeseesseeeeesssseseueeseseceane 172 
Mr. T. Wirson’s Short Account of the Darton Collieries’ Club.........0s0..+ 173 
Mr. G. R. Porrer’s Statistical View of the recent Progress and present 
Amount of Mining Industry in France, drawn from the Official Reports 
of the “ Direction Générale des Ponts et Chaussées et des Mines” ...... 174 
Colonel Syxes on the Statistics of Vitality in Cadiz .........cscecasseneeeneees 174 
Mr. Harz on an Outline for Subjects for Statistical Inquiries ............... 177 
Mr. Jerrries Kinestey’s Criminal Returns of the Empire ........ sade ent 


NOTICES AND ABSTRACTS 


OF 


MISCELLANEOUS COMMUNICATIONS 


TO THE SECTIONS. 


MATHEMATICS AND PHYSICS. 


On a General Geometric Method. By Cuar.es Graves, F.7.C.D. 


Mr. Graves was led to the views he was about to explain, from ob- 
serving the use in the doctrine of Conic Sections of a theorem given 
by M. Chasles, in his “ Histoire de la Géométrie,” viz., that “the en- 
harmonic relation of four lines drawn from four fixed points in a conic 
section, to any fifth point in the curve, will remain invariable.’ Mr. 
Graves explained the term “enharmonic relation,” as employed by 
M. Chasles, to mean the ratio of Sin. (a, d), Sin. (6, c) to Sin. (a, b) 
Sin. (¢, d); a, b,c, and d, being right lines diverging from the same point. 
He insisted on the importance of M. Chasles’s theorem, as a kind of 
geometrical characteristic of the conic sections, defining them like an 
equation ; and showed how it might be advantageously applied in the 
determination of loci, and also in the invention, proof, and generaliza- 
tion of theorems relating to the conic sections. In ascertaining whether 
the plane curve described by a point, subject to a certain condition, is 
a curve of the second degree or not, the general method that suggests 
itself is, to find four particular positions of the point, and to draw from 
these points right lines to any fifth point in the locus. If the enhar- 
monic relation of these four lines be invariable, the curve will be a 
conic section, and not otherwise. Among several exemplifications of 
this method, Mr. Graves discussed the problem of finding the locus of 
the centres of all the conic sections passing through four given points. 
The middle points of the sides of the quadrilateral, at whose angles are 
the given points, being evidently situated on the locus, it was sufficient - 
to show that the enharmonic relation of lines drawn from them to any 
VOL. vil. 1838. fem a 


2 EIGHTH REPORT—1838. 


other point in it was constant; and this follows immediately from a 
theorem announced by Mr. Graves, viz., that “the enharmonic relation 
of four diameters of a central conic section, is the same as that of their 
four conjugates.” In order to connect this mode of investigation with 
the ordinary algebraic method, Mr. Graves formed the equation of a 
conic section passing through the four points (2', 0), (—2"', 0), (0, y'), 


(0,—y"), (the axes of the co-ordinates being made to pass through the . 


points, ) and finding only the co-efficient of xy to remain indeterminate, 
he establishes the following equation between this co-efficient B, and (7) 
the enharmonic relation of four lines drawn from any point in the locus 
aly!" + ay —B 
aly! ds a i B 
deduced some elegant consequences, and pointed out the readiness with 
which M. Chasles’s theorem serves to group together, and to prove 
other very general ones ; such, for instance, as that of Pascal, relating 
to irregular hexagons, inscribed in conic sections, of which it furnishes 
by far the shortest and most elegant proof yet obtained. He concluded 
with the expression of a wish, that mathematicians would not disdain 
to employ the resources of geometry combined with analytic methods 
in the treatment of conic sections, many valuable properties of which 
have been lost sight of by those who seem to consider the study use- 
ful only as an exercise in the application of algebra to geometry. 


to the four given points, 7 = From this Mr. Graves 


A paper was read by Charles Ball, Esq., of Christ’s College, Cam- 
bridge, “On the meaning of the Arithmetical Symbols for Zero and 
Unity, when used in General Symbolical Algebra.” 


On the Propagation of Light in vacuo. By Professor Sir W. R. 
Hami.tTon, F.R.S. 


The object of this communication was to advance the state of our 
knowledge respecting the law which regulates the attractions or repul- 
sions of the particles of the ether on each other. The general differential 
equations of motion of any system of attracting or repelling points 
being reducible to the form 


ax 
ae =S.m,Azx f(r), (1.) 
the equations of minute vibration are of the form 


ce = S.m, (Az. f(r) + Av.df(r)), (2.) 


of (7) =f" (7) er, (3.) 
A 


Se AO KS got A a eo, (4.) 
ae Tr ite 


in which 


and 


EE EE 


> 


TRANSACTIONS OF THE SECTIONS. 2 


A mode of satisfying the differential equations (2), and at the same 
time of representing a large class of the phenomena of light, is to as- 
sume, 


Paige 09 2 uonst, 4: eos: Sse esate heed (5.) 


es 
in which &, n’, ¢° are constants, depending on the extent and direction 
of vibration: a, 6, c, are the cosines of the inclinations of the direction 
of propagation of a plane wave to the positive semi-axes of x,y, 2; v 
is the velocity of propagation of that wave, and X is the length of an 
undulation; and z is the semicircumference of a circle, of which the 
radius is unity. With this assumption (5.), and with a natural and 
obvious supposition respecting a certain symmetry of arrangement in 
the ether, causing the sums of odd powers to vanish, it is permitted to 


substitute in (2.) the expressions 


doa Qrv 

—_—s = WF 4 ¥ 

dt? i x ) a | (6.) 

Ada = — vers. A 0.32, Gs 
in which A@= — "7 (qx +bAy + Az); (8.) 


and thus arises a system of conditions of the form 
ZU Nee ves A 2? 4, 
ECE) Ss om8. LF) +A F1)| vers. a0 


+ mS. 52 2Y 1 (7) vers. A 


he Ss = fevers. A 8 (9.) 


T- , 
the masses m‘ of the etherial particles, being supposed each = m, 


Three conditions of this form (9.) exist for every particle, and deter- 


mine, in general, for any given values of a, b, c, X, that is, for any 
given direction of propagation, and any given length of wave, the value 
of v, and the ratios of &, n, 2, that is, the velocity of propagation of 
the wave, and the direction of vibration of the particle. Accordingly, 
with some slight differences of notation, they have been proposed for 
this purpose by Cauchy, and adopted by other mathematicians. Sup- 
pose now, for simplicity, that the plane wave is vertical, so thate =o; 
and let, at first, the direction of its propagation coincide with the posi- 
tive semi-axis of x, sO that 6 also vanishes, and a is = }. Then, for 
transversal vibrations, the expression for the square of the velocity of 
propagation is 


v= ()ms {F() + ASS (0) | vere, 22 A, (10.) 


which appears to extend not only to the interplanetary spaces, but also 
to all ordinary transparent media, and contains, for them, the theore- 
B2 


4 EKIGHTH REPORT—1838. 


tical law of dispersion, which was first discovered by Cauchy, namely, 
the expression 
C= A Ane Aa kt eee (11.) 
in which 
(2 7)%m s{ ; r? — Az? ,, Le 
SS > =— A r2i+2, N 
Ai=193.4..(i+2) NS alias se OF: at#+2, (12.) 


But, in order that this law may agree with the phenomena, it is es-- 
sential that the series (11.) should be convergent, even in its earliest 
terms; and this consideration enables us to exclude the supposition 
which has occurred to some mathematicians, that the particles of the 
ether attract each other with forces which are inversely as the squares 
of the distances between them. For if we suppose rf (7) = r—?, and 
therefore f(r) = r—3, f’ (r) = — 3 r.—4, we shall have 


=4 ee.” {— -—3 —5 I 
A, 2 984<@i+) © na on see 


Axrit?; (13.) 


and by extending the summation to particles, distant by several times 
the length of an undulation from the particle which they are supposed 
to attract, these sums (13.) become extremely large, and the terms of 
the series (11.) diverge very rapidly at first, though they always finish 
by converging. In fact, if we conceive a sphere, whose radius = 2 A 
=n times the length of an undulation (7 being a large multiplier), 
and whose centre is at the attracted particle ; and if we consider only 
the combined effect of the actions of all the particles within this sphere, 
we may, as a good approximation, convert each sum (18.) into a triple 
definite integral, and thus obtain, for the general term of the series 
(11.), the expression 


(1) Apo = 


(—1)4armn2nw (27 nj? (14) 

(Zit 5)  ° 1.2.3... (27 + 3)’ ; 
e being the mean interval between any two adjacent particles of 
the ether, so that the number of such particles contained in any 


4 3 73 


$6 


sphere of radius 7, is nearly = , if r be a large multiple of e. 


And hence we find, by taking the sum of all these terms (14.), the ex- 


pression ‘ be 
2m cos.2 7 2 sin. 277 
faa a pe eS ee ee Ne : 

: 7 €8 {3+ (2am)? Gear} (15.) 
so that, by taking the limit to which v2 tends, when is taken greater 
and greater, we get at last as a near approximation 


_ Am 
Tiere (16.) 


v2 


and 
RL, [ore a7.) 


v m1 


TRANSACTIONS OF THE SECTIONS. 5 


But » expresses the time of oscillation of any one vibrating particle ; 
v 


this time would therefore be nearly constant, if the particles attracted 
each other according to the law of the inverse square of the distance ; 
and consequently this law is inadmissible, as being incompatible with 
the law of dispersion. It had appeared to Sir William Hamilton im- 
portant to reproduce these results, though he remarked that they 
agree substantially with those of Cauchy, because the law of the in- 
verse square was one which naturally offered itself to the mind, and 
had, in fact, been proposed by at least one mathematician of high 
talent. There was, however, another law which had great claims on 
.the attention of mathematicians, as having been proposed by Cauchy 
to represent the phenomena of the propagation of the light 7m vacuo, 
namely, the law of a repulsive action, proportional inversely to the 
fourth power, or to the square of the square of the distance. M. 
Cauchy had, indeed, supposed that this law might hold good only for 
small distances, but in examining into its admissibility, it appeared 
fair to treat it as extending to all the neighbouring particles which act 
on any one. But against this law also, Sir William Hamilton brought 
forward objections, which were founded partly on algebraical, and 
partly on numerical calculations, and which appeared to him decisive. 
The spirit of these objections consisted in showing that the law in 

question would give too great a preponderance to the effect of the 
immediately adjacent particles, and would thereby produce irregu- 
larities which are not observed to exist. In particular, if it be supposed 
that 

S.rt Ag? =S.7r' Ay?= S.ri A 2%, 

S.riAat=S.ridyt=S.ria 24, 

S.riAatAy? =S.riAyAz?=S8.ri Az? Az, 


and also, in (5.), that e = 0, a = 6, and that d is much greater than e, 
it is found that the two values v? and v? of the square of the velocity 
v, corresponding to vertical and to horizontal but transversal vibra- 
tions, are connected by the relation 


being expressed as follows : 
oe = Ss (sr [os dale ry, 


3 —3 =f 
va S(r —5r Ant); 
8 - 
In conclusion, he offered reasons for believing that the law of 
action of the particles of the ether on each other resembles more the 
Jaw which Poisson has in one of his memoirs proposed as likely to 


6 EIGHTH REPORT—1838. 


express the mutual action of the particles of ordinary and solid bodies, 
being perhaps of some such form as the following :— 


(ey -(5)" 
f(r) Ss = aw. BS Paneer ayes (18.) 
b and 6, being each greater than unity, and g, g,, h, h, being some large 


positive numbers, while a and a, are constant and positive multipliers, - 


and e is, as before, the mean or average interval between two adjacent 
particles. With such a law there would be a nearly constant repulsion, 


if a be greater than a,, and if g be less than g,, as long as aa is sensi- 
€ 


bly less than unity; but the force would rapidly change, as the distance 
r approached to g e, and would then become a nearly constant attraction, 
until r became nearly = g,e ; it would then diminish rapidly, and soon 
become insensible. Sir William Hamilton did not, however, intend to 
exclude the hypothesis, that the function rf (7) may contain several 
alternations of such repulsive and attractive terms,—much less did he 
deny that at great distances it may reduce itself to the law of the in- 
verse square. 


On the Propagation of Light in Crystals. By Prof. Sir W. R. 
Hamitton, F.R.S. 


By continuing to modify the analysis of M. Cauchy in the manner 
already explained, he had succeeded in deducing, more satisfactorily 
than had in his opinion been done before, from dynamical principles, 
a large and important class of the phenomena of light in crystals ; 
though much still remained to be done before it could be said that a 
perfect theory of light was obtained. He had employed, for the pur- 
poses of calculation, the supposition that the arrangement of the parti- 
cles of the ether in a crystal differs from an exactly cubical arrangement 
only by very small displacements, caused by the action of the particles of 
the crystalline body ; and had attended only to those indirect or reflex 
effects of the latter particles which are owing to the disturbances which 
they produce in the arrangement of the former particles: but he did 
not mean to assert that he had established any strong physical pro- 
bability for this being the true modus operandi in crystals, though 
he thought the hypothesis had explained so much already that it de- 
served to be still further developed. 


On some Points connected with the Theory of Light. By Professor 
Powe tL, F.R.S. 


At the last meeting, the author dwelt on the importance of extending 
observations on the refractive indices for the standard rays to more 
highly dispersive media. In prosecuting these inquiries, he has to re- 


Bde tos 


TRANSACTIONS OF THE SECTIONS. 7 


port that a prism of chromate of lead, owing to the nature of the sub- 
stance, will not enable him to determine the indices, as the whole spec- 
trum is confused, no lines visible, and the violet end totally absorbed. 

In the identification of certain of the standard rays of Fraunhofer 
some discrepancy appeared to exist between different representations. 
The author’s attention is now directed to this point, among others 
connected with a more accurate repetition of his former approximate 
determinations of refractive indices, on which he is now engaged. 

He wishes also to draw attention to questions connected with the 
application of photometry to the theory ; especially to that referring to 
the power of the eye to judge of the equalization of lights, and the in- 
fluence which the illumination of one space has upon that of another in 
juxtaposition. To show how great the uncertainty is, the following 
very simple experiment may be referred to. On receiving the rays of 
a candle on a white screen, and intercepting a portion of them by a 
clear plate of glass, the eye can recognise no difference in the illumi- 
nation of the covered part. Yet, from both the first and second sur- 
faces of the glass, there is a copious reflection. 

With regard to the mathematical theory, he alludes to the important 
researches of Mr. Tovey, especially those on elliptic polarization. All 
the preceding investigations for integrating the differential equations for 
waves, including the dispersion, have proceeded on the supposition that 
certain terms vanish. This appears essential to the general solution. 
Mr. Tovey has, however, shown, that if those terms do not vanish, we 
have still a particular solution: and this applies to the case of light 
elliptically polarized. This case is absolutely excluded in the former 
investigations, which are therefore imperfect. The author has endea- 
voured to clear up some points connected with this inquiry. Upon the 
evanescence or non-evanescence of these terms simply depends the el- 
liptie, circular, or rectilinear character of the vibrations. Corresponding 
to these mathematical conditions, are those of the arrangement of the 
ztherial molecules in the medium, or part of the medium, where the 
polarization is communicated. He has pointed out the connexion be- 
tween these views and the investigations of Prof. Maccullagh, in which 
that gentleman connects with certain equations of motion the elliptic 
polarization in quartz, by which Mr. Airy had explained the results 
and laws of M. Biot. 


On an Ocular Parallax in Vision, and on the Law of Visible Diree- 
tion. By Sir D. Brewster, K.H., F.R.S. 


The honour of suggesting or illustrating the law of visible direction 
belongs, said Sir David Brewster, to Dechales, Porterfield, and Reid. 
D’Alembert, in his “ Doutes sur différentes questions d’Optique*,” 
maintains that the action of light upon the retina is conformable to the 


* Opuscules Mathématiques, tom. i. p. 266, 268, 


8 EIGHTH REPORT—1838. 


Jaws of mechanics ; and he adds, that it is difficult to conceive how the 
object could be seen in any other direction than that of a line perpen- 
dicular to the curvature of the retina, at the point where it is really ex- 
cited. He then proceeds to investigate mathematically how the ap- 
parent magnitudes of objects would be affected, on the two suppositions, 
that the line of visible direction coincided with the refracted ray, or 
with a line perpendicular to the retina, at the point where the refracted 
ray fell upon it. On the first supposition, he finds that the apparent 
magnitude of small objects would be increased about 1-13th or 1—16th, 
if the anterior surface of the crystalline is supposed to have a radius of 
six lines in place of four. On the second supposition, namely, that 
of Porterfield and Reid, he finds that the apparent magnitude of objects 
would be increased nearly one-third, which, as he remarks, being con- 
trary to experience, we cannot suppose that vision is thus performed, 
however natural the supposition may appear. ‘“ According to what 
line then,” he continues, “do we perceive objects or visible points, 
which are not placed in the optic axis? This is a point which it ap- 
pears very difficult to determine exactly and rigorously. However, as 
experience proves that objects of small extent, which are within the 
range of our eyes, do not appear sensibly greater than they are in 
reality, it follows, that the visible point, which sends a ray to the cornea, 
is seen sensibly in its place, and, consequently, this visible point is seen 
sensibly in the direction of a line joining the point itself and its image 
on the retina. But why is this the case? It is a fact which I will not 
undertake to explain*.” This abandonment of the inquiry will appear 
the more remarkable, when we consider the assumptions from which 
D’Alembert has deduced the preceding results. He takes for granted 
the dimensions of the eye as given by Petit and Jurin ; and he assumes 
Jurin’s Index of Refraction for the human crystalline lens, though it is 
almost exactly the same as that of an ox, as given by Hawksbee. These, 
indeed, were the best data he could procure; but he should have inquired 
if the most probable law of visible direction was compatible with any 
other dimensions of the eye, and any other refractive powers of the hu- 
mouts, which were within the limits of probability; and, above all, he 
ought to have examined experimentally the truth of his fundamental 
assumption, that visible points are really seen in their true places when 
they are not in the axis of vision. In submitting this assumption to 
experiment, I had no difficulty in ascertaining that there exists an ocular 
parallax, and that this parallax is the measure of the deviation of the 
visible from the real direction of objects. It is nothing in the axis of 
the eye, and increases as the visible point is more and more distant from 
that axis ; and hence it follows, that during the motion of the eye, when 
the head is immoveable, visible objects do not appear absolutely fixed, 
and have an apparent magnitude greater than their real magnitude. 
We are, consequently, not entitled to reject any law of visible direction, 
on the ground of its giving a position to visible points, and a magnitude 


* Opuscules Mathématiques, tom. i. p. 27. 


TRANSACTIONS OF THE SECTIONS. 9 


to visible objects, different from their true position and magnitude. 
Having removed this difficulty, I proceeded to examine the other data 
upon which D’Alembert reasoned. According to the anatomy of the 
eye which he adopted, the centre of curvature of the retina, which he 
supposes to be spherical, (as he does the eye-ball,) is equidistant from 
the extremity of the axis, or the foramen ovale, and the centre of the 
crystalline lens. This, however, is far from being the case. M. Dutour, 
M. Maurice, a recent and able writer on vision, and, which is of more 
consequence, Dr. Thomas Young, have all made the centre of curva- 
ture of the retina, at the bottom of the eye, coincident with the centre 
of the spherical surface of the cornea ; and this centre, in place of being 
almost half way between the apex of the posterior surface of the lens 
and the foramen ovale, is actually almost in contact with that apex. The 
dissections of Dr. Knox, and of Mr. Clay Wallace, of New York, give 
results conformable with those of Dr. Young; and almost all these 
authors regard the human eye as a spheroid. When we add to these 
considerations the fact that the refractive power of the crystalline lens 
assumed by D’Alembert is nearly triple of what it really is, we have no 
scruple in concluding that the results of his calculations are inadmissible. 
Assuming, then, the most correct anatomy of the eye, namely, that 
according to which the cornea and the bottom of the retina have the 
same centre of curvature, it is very clear that if there was no crystalline 
lens, pencils incident perpendicularly upon the cornea will pass through 
this common centre, and fall perpendicularly upon the retina. Hence, 
in this case, the line of visible direction will coincide with the line of 
real direction, and also with the incident and refracted ray, and will 
likewise pass through the centre of curvature of the retina. Now, the 
refractions at the surfaces of the crystalline are exceedingly small, and 
at moderate inclinations to the axis the deviations from the preceding 
law are very minute. At an inclination of 30°, a line perpendicular to 
the point of impression on the retina passes through the common centre 
already referred to, and does not deviate from the line of real visible 
direction more than half a degree, a quantity too small to interfere with 
the purposes of vision. At greater inclinations to the axis of the eye, 
the deviation of course increases ; but as there is no such thing as di- 
stinct vision out of the axis, and as the indistinctness increases with the 
inclination of the incident ray, it is impossible to ascertain by ordinary 
observation that such a deviation exists. Hence, the mechanical prin- 
ciple of D’Alembert, and the law of Dr. Reid, are substantially true. 
If the retina is spheroidal, the centre of visible direction will shift its 
place along the axis of vision, and will correspond to the points where 
lines perpendicular to the surface of the spheroid cut its lesser axis. 
As the Almighty has not made the eye achromatic, because it was un- 
necessary, so he has, in the same wise economy of his power, not given 
it the property of seeing visible points in their real directions. 


10 EIGHTH REPORT—1838. 


On a New Phenomenon of Colour in certain specimens of Fluor Spar. 
By Sir D. Brewster. Z 


Mineralogists have long ago observed, in certain varieties of fluor 
spar, a beautiful blue colour, different from that which is seen by trans- 
mitted light. Haiiy noticed this property in some of the fluor spars 
from Derbyshire. Succeeding mineralogists, however, have confounded. 
this colour with the ordinary tints of the spar, and, so far as the author ~ 
knows, its nature and origin have not been successfully investigated. In 
describing a species of dichroism, noticed by Dr. Prout* in the purpu- 
rates of ammonia and potash, Sir John Herschelt ascribes the reflected 
green light to “some peculiar conformation of the green surfaces, pro- 
ducing what may be best termed a superficial colour, or one analogous 
to the colour of thin plates, and striated or dotted surfaces.” And he 
adds—* A remarkable example of such superficial colour, differing 
from the transmitted tints, is met with in the green fluor of Alston 
Moor, which on its surfaces, whether natural or artificial, exhibits, in 
certain lights, a deep blue tint, not to be removed by any polishing.” 
As the phenomenon which Sir D. Brewster had studied in the Derby- 
shire fluors was clearly one of internal structure, he was led to sup- 
pose that the superficial colour seen by Sir John Herschel on the 
Alston Moor specimens, belonged to another class of phenomena; but 
having attempted in vain to communicate the blue colour of the Alston 
Moor crystals to wax or isinglass, he is disposed to believe that the 
two phenomena are identical. In the fluors from Derbyshire, which 
consist of differently coloured strata parallel to the faces of the cube, 
the blue colour is most powerfully developed in the purplish brown or 
bluish brown strata, in a less degree in the greenish strata, and scarcely, 
if at all. in those layers which are colourless by transmitted light. In 
the first of these cases, the blue colour may be distinctly seen emanating 
from the interior of the crystal, when it is held in the common light of 
day. In the sun’s light the colour is still more brilliant; but the effect 
may be greatly increased by covering the greater part of the crystal 
with black wax, or by immersing it in a trough of glass covered ex- 
ternally with wax, and containing an oil of nearly the same refractive 
power as the spar. If there are fissures within the crystal, they will 
greatly influence the effect of the experiment, by reflecting to the eye 
the transmitted light. In order, however, to witness this experiment 
in all its beauty, and to have ocular evidence of its nature and charac- 
ter, a beam of condensed solar light should be transmitted through the 
crystal, as shown in the annexed figure, where L L is the condensing 
lens, F its focus, and m Nn the system of differently coloured layers, tra- 
versed by the cone of refracted rays. The first layer of spar reflects 
in all directions an intensely blue light; the two adjacent layers (sepa- 
rated by a thin layer which reflects blue light) reflect a light nearly 
white; the next layer gives a blue of exceeding brilliancy; and so on 
with the other layers, till the cone reaches the brown central nucleus, 
which also reflects a rich blue tint, though inferior to that of one of 


* Phil. Trans. 1818, p. 424. + Treatise on Light, sec. 1076. 


TRANSACTIONS OF THE SECTIONS. Il 


the preceding layers. In the green fluor of Alston Moor there are 
also different layers, some of which are pink, and some of different 
shades of green ; but the different shades of blue which they give out 
under exposure to strong light, are not so strikingly contrasted as in 
the Derbyshire specimens. As the blue colour now described is re- 
flected from surfaces within the spar, and as it does not occur in all 


specimens, nor in every part of the same crystal, it must be produced 
by extraneous matter of a different refractive power from the spar, in- 
troduced between the molecules of the crystal during its formation. 
That the blue colour is not produced by shallow cavities or minute 
‘pores, as in some of the opals, is inferred from the perfect transparency 
of the specimens in which it occurs, and from the fact that the same 
reflected tints are found in fluids, particularly the juices of plants ex- 
tracted by alcohol, and in several artificial glasses, particularly in those 
of a pink and orange colour, the former of which give a blue and the 
latter a green colour. Having found that some of the dichroitic colours 
in doubly refracting crystals were discharged by heat, it occurred to the 
author that the blue tints in fluor spar might suffer a similar change, 
and might even be connected with the phosphorescence of the mineral. 
He therefore exposed two pieces, one of the Derbyshire and one of the 
Alston Moor fluor, to a considerable heat. Both of them gave out a 
blue phosphorescence, similar to that of the reflected tint, and much of 
the natural colour of the fragments was discharged by the heat. In 
both specimens the blue reflected tint was greatly diminished. In an- 
other specimen of the Alston Moor fluor, it appeared to be wholly re- 
moved ; but in a third, taken from the solid angle of the cube, the 
blue tint still appeared, though with an impaired brilliancy. It is pos- 


12 EIGHTH REPORT—1838. 


sible, that a very intense heat might discharge the blue tint altogether, 
but it is difficult to obtain satisfactory results with a mineral which de- 
crepitates by the action of heat, and thus prevents the observer from 
comparing the tints under circumstances exactly the same. 


An Account of certain New Phenomena of Diffraction. 
By Sir D. Brewster. 


The phenomena of the inflexion or the diffraction of light observed 
by Sir Isaac Newton, Fresnel, and others, were those which are visible 
at a greater or less distance behind the diffracting body, and according 
to the undulatory theory they are produced by the secondary waves 
which fall converging on the points where the fringes appear within and 
without the geometrical shadow. These fringes are all calculable by a 
formula given by Fresnel, depending on the relation of the two quan- 
tities a and 6, a being the distance of the place where the fringes are 
formed from the diffracting body, and 6 the distance of the diffracting 
body from the point from which the beam of light diverges. In the 
phenomena hitherto studied, the quantity a is always positive. The 
new phenomena discovered and described by Sir David Brewster are 
those in which a is negative ; and they may be represented by a formula 
differing from Fresnel’s only in the sign of a. These new phenomena 
are rendered visible by bringing lenses of different foci in contact with 
the diffracting body, and the fringes seen in any case are those belong- 
ing to a value of —a equal to the focal distance of the lens. The fringes 
are in this case produced by the secondary waves, which proceed 
diverging from the main wave, from a point between the diffracting body 
and the luminous centre, whose distance from the former is a. When 
—a is equal to 6, the fringes are formed in parallel rays ; and when the 
diffracting body is placed between the lens and the eye, they are formed 
in converging rays. Hence, in studying these phenomena, we may use 
a telescope with a micrometer, and obtain accurate measures. These 
phenomena were illustrated by diagrams. 


An Account of an Analogous Series of New Phenomena of Diffrac- 
tion when produced by a Transparent Diffracting Body. By Sir 
D. BREWSTER. 


These phenomena, when carefully produced by the various methods 
which he explained, exhibited a series of splendidly coloured bands of 
light, sometimes perfectly symmetrical and sometimes unsymmetrical, 
accordingly as the diffracting body was regular or irregular in its section; 
and the author remarked, that an instrument could thus be constructed 
for giving new patterns of ribands of all forms and colours. The theory 
of the phenomena he considered quite simple and obvious, but he stated 
that a comparison of the results of theory and experiment would be 
difficult, from the difficulty of ascertaining the exact form of the dif- 
fracting body. 


TRANSACTIONS OF THE SECTIONS. 13 


On the Combined Action of Grooved Metallic and Transparent Sur- 
faces upon Light. By Sir D. Brewster. 


The phenomena described in this paper, discovered by the author, 
were altogether new and of a very remarkable description. The spectra, 
produced by the methods which were explained to the meeting, were 
covered with bands like those produced by the action of nitrous gas 
upon the spectrum, and the phenomena varied with the distance of the 
grooves, with the relation of the dark and luminous intervals, and with 
the inclination of the incident ray. Sir David Brewster described 
analogous phenomena and others of a remarkable character when the 
grooves were made in ¢ransparent surfaces; and he explained to the 
Section the manner in which he conceived the phenomena were pro- 
duced, on the principles of interference. 


On a New Kind of Polarity in Homogeneous Light. 
By Sir D. BrewsTeEr. 


At the last meeting of the Association Sir D. Brewster communi- 
cated an account of a new property of light, which did not admit of 
any explanation. Since that time he has had oceasion to repeat and 
vary the experiments; and having found the same property exhibited 
in a series of analogous though different phenomena, he has no hesi- 
tation in considering this property of light as indicating a new species 
of polarity in the simple elements of light, whether polarized or unpo- 
larized. In the original experiment, two pencils of perfectly ho- 
mogeneous light, emanating from the same part of a well-formed 
spectrum, interfered after one of them had been retarded by trans- 
mission through a thin plate of glass. The fringes were exceedingly 
black, but no phenomena of colour were visible. He was anxious to 
observe what would take place when the retarded pencil passed through 


the edges of various plates differing very little in thickness, so that dif- 


ferent parts of it suffered different degrees of retardation, for the pre- 
ceding experiment entitled him to expect a series of overlapping bands 
and lines of different sizes. In making such an experiment, however, 
he encountered great difficulties, and he failed in every attempt to com- 
bine such a series of thin edges. He had recourse therefore to lami- 
nated crystals, and in an accidental cleavage of sulphate of lime he ob- 
tained the desired combination of edges. “Upon looking through this 
plate at a perfect spectrum, in the manner described in my former com- 
munication, I was surprised to observe a splendid series of bands and 
lines crossing the whole spectrum, and shifting their place and changing 
their character by the slightest inclinations of the plate. But what sur- 
prised me most was to perceive that the spectrum exhibited the same 
phenomena as if it had been acted upon by absorbing media, so that 
we have here dark lines and the effects of local absorptions produced 
by the interference of an unretarded pencil with other pencils, proceed- 
ing in the same path with different degrees of retardation. The bear- 
ing of this unexpected result upon some of the most obscure questions 


14 EIGHTH REPORT—1838. 


in physical optics, I may have another opportunity of explaining. At 
present, I beg the attention of the meeting to another part of the ex- 
periment. We have seen that the effects of interference are distinctly 
developed in a certain position of the retarding plates. This position, 
when the effects are most distinct, is that in which the edges of the 
plates are turned towards the red end of the spectrum and are parallel 
to its fixed lines. If we give the plates a motion of rotation in their 
own plane, the bands and lines and the phenomena of absorption be-' 
come less and less distinct as the angle between the edges of the plates 
and the lines of the spectrum increases. When this angle is 90° the 
bands disappear altogether, and during the next 90° of rotation they 
continue invisible. At 270° of azimuth they begin to reappear, and 
attain their maximum distinctness at 360°, when they have returned to 
their original position. Here then we have certain phenomena of in- 
terference, and also of absorption, distinctly exhibited when the least 
refrangible side of the retarded ray is towards the most refrangible 
side of the spectrum, or towards the most refrangible side of the unre- 
tarded ray ; while the same phenomena disappear altogether when the 
most refrangible side of the retarded ray is towards the least refrangible 
side of the unretarded ray ; and between these two opposite positions 
we have phenomena of an intermediate character. Hence I conclude, 
that the different sides of the rays of homogeneous light have different 
properties when they are separated by prismatic refraction or by the 
diffraction of grooved surfaces or gratings,—that is, these rays have po- 
larity. When light is rendered as homogeneous as possible by absorp- 
tion, or when it is emitted in the most homogeneous state by certain 
coloured flames, it exhibits none of the indications of polarity above 
mentioned. The reason of this is, that the more or less refrangible 
sides of the rays lie in every direction, but as soon as these sides are 
arranged in the same direction by prismatic refraction or by diffraction, 
the light displays the same properties as if it had originally formed part 
of a spectrum.” 


On some Preparations of the Eye by Mr. Clay Wallace, of New 
York. By Sir D. Brewster. 


Sir David Brewster laid before the Section a series of beautiful pre- 
parations of the eye made by Mr. Clay Wallace, an able oculist in 
New York, calculated to establish some important points in the theory 
of vision. Mr. Clay Wallace, he stated, considers that he has discovered 
the apparatus by which the eye is adjusted to different distances. This 
adjustment is, he conceives, effected in two ways. In eyes which have 
spherical lenses it is produced by a falciform, or hook-shaped muscle, 
attached only to one side of the lens, which by its contraction brings 
the crystalline lens nearer the retina. In this case, it is obvious that 
the lens will have a slight motion of rotation, and that the diameter, 
which was in the axis of vision previous to the contraction of the mus- 
cle, will be moved out of that axis after the adjustment, so that at dif- 


eR 


TRANSACTIONS OF THE SECTIONS. 15 


ferent distances of the lens from the retina different diameters of it will! 
be placed in the axis of vision. As the diameters of a sphere are all 
equal and similar, Mr. Clay Wallace considered that vision would be 
equally perfect along the different diameters of the lens, brought by 
rotation into the axis of vision. Sir David Brewster, however, remarked 
that he had never found among his numerous examinations of the lenses 
of fishes any which are perfectly spherical, as they were all either 
oblate or prolate spheroids, so that along the different diameters of the 
solid lens the vision would not be similarly performed. But, inde- 
pendent of this circumstance, he stated that in every solid lens there 
was only one line or axis in which vision could be perfectly distinct, 
namely, the axis of the optical figure, or series of positive and negative 
luminous sectors, which are seen by the analysis of polarized light. 
Along every other diameter the optical action of the lens is not sym- 
metrical. When the lens is not a sphere, but lenticular, as in the 
human eye or in the eyes of most quadrupeds, Mr. Clay Wallace con- 
siders that the apparatus for adjustment is the ciliary processes, to 
which this office had been previously ascribed, though not on the same 
scientific grounds as those discovered by Mr. Wallace. One of the 
most important results of Mr. Wallace’s dissections is the discovery of 
Sibres in the retina. These fibres may be rendered distinctly visible. 
They diverge from the base of the optic nerve, and surround the fora- 
men ovale of Soemmerring at the extremity of the eye. Sir John Her- 
schel had supposed such fibres to be requisite in the explanation of 
the theory of vision, and it is therefore doubly interesting to find that 
they have been actually discovered. 


On the Structure of the Vitreous Humour of the Eye of a Shark. 
By Sir J. W. F. Herscuetr, Bart. 


Sir J. Herschel states, that while crossing the Atlantic on his return 
from the Cape, a shark was caught in lat. 2° N. and long. about 20° W. 
Having procured the eyes, which were very large, and extracted the 
crystalline lenses, the vitreous humour of each, in its capsule, presented 
the usual appearance of a very clear, transparent, gelatinous mass, of 
little consistency, but yet forming, very distinctly, a connected and 
continuous body, easily separable from every other part. Wishing to 
examine it more narrowly, it was laid to drain on blotting-paper; and, 
as this grew saturated, more was applied, till it became apparent that 
the supply of watery liquid was much too great to be accounted for by 
adhering water or aqueous humour. “ Becoming curious to know to 
what extent the drainage might go, and expecting to find that, by car- 
rying it to its limit, a gelatinous principle of much higher consistency 
might be insulated, I pierced it in various directions with a pointed in- 


'strument. At every thrust a flow of liquid, somewhat ropy, but de- 


eidedly not gelatinous, emanated ; and, by suspending it on a fork, and 
stabbing it in all directions with another, this liquid flowed so abun- 


16 EIGHTH REPORT—1838. 


dantly, as to lead me to conclude that the gelatinous appearance of this 
humour, in its natural state, is a mere illusion, and that, in fact, it con- 
sisted of a liquid no way gelatinous, inclosed in a structure of trans- 
parent and, consequently, invisible cells. The vitreous humour of the 
other eye, insulated as far as possible, was therefore placed in a saucer, 
and beaten up with a fork, in the manner of an egg beaten up for culi- 
nary purposes. By this operation, the whole was resolved into a clear 
watery liquid, in which delicate membranous flocks could be perceived,” 
and drawn out from the water in thready filaments, on the end of the 
fork. From this experiment, it is clear that the vitreous humour (so 
ealled) of this fish is no jelly, but simply a clear liquid, inclosed in some 
close cellular structure of transparent membranous bags, which, by 
their obstruction to the free movements of the contained liquid, imitate 
the gelatinous state.” 


On Binocular Vision ; and on the Stereoscope, an instrument for illus- 
trating its phenomena. By Professor WHEATSTONE. 


Professor Wheatstone stated that, at the last meeting of the Royal 
Society, he had presented the first of a series of papers on the phe- 
nomena of vision, in the investigation of which subject he had been 
for some years engaged. On the present occasion he proposed merely 
to state so much as would enable him to explain the experiments which 
the apparatus on the table was intended to exhibit. This apparatus he 
called a Stereoscope, from its property of presenting to the mind the 
perfect resemblances of solid objects. To understand the principles on 
which it was constructed, he explained the circumstances which enable 
us to distinguish an object in relief from its representation on a plane 
surface; he showed that when a solid object, a cube for instance, was 
placed at a short distance before the eyes, its projections on the two 
retin form two dissimilar pictures, which in some cases are so different, 
that even the eye of an artist would with difficulty recognise them as 
representations of the same object ; notwithstanding this dissimilarity 
of the two pictures, the object is seen single; and hence it is evident 
that the mind perceives the object in relief, im consequence of the 
simultaneous perception of the two monocular pictures. He next 
showed, that if the object were thus drawn, first as it appears to the 
right eye, and then as it appears to the left eye, and those two pictures 
be presented one to each retina, in such manner that they fall on the 
parts as the projections from the object itself would, the mind perceives 
a form in relief, which is the perfect counterpart of the object from 
which the drawings have been taken: the illusion is so perfect, that no 
effort of the imagination can induce the observer to suppose it to be a 
picture on a plane surface. Professor Wheatstone described various 
modes by which the two monocular pictures might be made to fall on 
similar parts of the two retine ; but he gave the preference to a method 
which may be understood by the annexed diagram. 


ia 


TRANSACTIONS OF THE SECTIONS. 17 


e é are the two eyes of the observer placed before two 
plane mirrors, inclined to each other at an angle of 
. 90°; the axes of the eyes converge to a point c; the 
\ pictures pp’ are so placed on sliding panels, that 
\.| their reflected images may he adjusted to appear at 
ae the place of convergence of the optic axis; it is ob- 
F ? vious, then, that the pictures on the retinz will be 
precisely the same as if they proceeded from a real object placed at e. 
In this manner may solid geometrical forms, crystals, flowers, busts, 
architectural models, &c. be represented with perfect fidelity, as if the 
objects themselves were before the eyes. The law of visible direction, 
which is universally true, for all cases of monocular vision, may, Pro- 
fessor Wheatstone stated, be extended to binocular vision, by the 
following rule: That every point of an object of three dimensions is 
seen at the intersection of the two lines of visible direction, in which 
that point is seen by each eye singly. 


Observations on Stars and Nebule at the Cape of Good Hope. 
By Sir Joun F. W. Herscuer, Bart. F.RS., Se. 


The notice of these observations laid before the Section reduced 
itself to the following heads : 

Reduced Observations of 1232 Nebulz and clusters of Stars, made 
in the years 1834, 5, 6, 7, 8, at the Cape of Good Hope, with the 
twenty-feet Reflector. 

Reduced Observations of 1192 Double Stars of the Southern He- 
misphere. 

Micrometrical Measures of 407 principal Double Stars of the South- 
ern Hemisphere, made at the Cape of Good Hope, with a seven-feet 
Achromatic Equatorial Telescope. 

A List of the Approximate Places of fifteen Planetary and Annular 
Nebulz of the Southern Hemisphere, discovered with the twenty-feet 
Reflector. 

Drawings illustrative of the Appearance and Structure of three 
principal Nebulz in the Southern Hemisphere. 

The observations in the first two of these communications form parts 
of two catalogues of southern nebulz and double stars respectively, 
which comprehend the chief results of the author's astronomical obser- 
vations at the Cape. They are complete only as far as the first nine 
hours in right ascension. In the other hours, only a few of the objects 
which occur are added, being the results of a partial and very incom- 
plete reduction of the observations in those hours. Sir John Herschel 
considered it probable, that when the reduction of his observations 
shall enable him to complete these catalogues, the total number of ob- 
jects contained in them will be nearly doubled. The first catalogue 
contains all the nebule and clusters comprised in the two Magellanie 
clouds, which are very. numerous. Each reduced observation ex- 
presses the mean right ascension and north polar distance of the 

VOL. VII. 1838. Cc 


18 EIGHTH REPORT—1838. 


object for the beginning of 1830, together with a description (in ab- 
breviated language), more or less detailed, ofits appearance and phy- 
sical peculiarities—as to size, degree of brightness, condensation, &e. 
The observations of double stars in the second catalogue express the 
mean place for the epoch above named—the angle of position of the 
stars with the meridian, as micrometrically measured at the time of 
observation—the estimated distance, and the magnitude assigned to 
each star, together with a column of remarks, in which peculiarities of 
colour or other phenomena are noted. The micrometrical measures in 
the third paper were taken with the same achromatic and micrometer, 
and are arranged in precisely the same manner as the former similar 
observations made by the author, which have been printed in the Trans- 
actions of the Astronomical Society. Among the principal double 
stars in this work occur, a Centauri, a Crucis, y Centauri, y Lupi, 
p Lupi, x Lupi, 6 Hydr, e Chameleontis, y Piscis Volantis, y Coron 
Australis, &e. Of these, the measures therein stated afford unequi- 
vocal evidence of rotation in several of the double stars, among which 
may be particularized a Centauri, 3 Hydra, y Coron, and 7 Lupi. 
In the case of a Centauri, the diminution of distance, even within the 
comparatively short period of observation, is remarkable; and the 
author stated verbally, that on examining the catalogue of the Astro- 
nomical Society, that of Captain Johnson, and the Paramatta Cata- 
logue, in all which the places of the two stars are given separately, 
he finds this diminution of distance fully borne out, and regularly pro- 
gressive; from which he is led to conclude, that in no great number 
of years from the present time (fifteen or twenty), the stars may be 
expected to appear in contact, or to be actually occulted one by the 
other, as has recently been observed to happen to y Virginis. The 
fourth of these communications is a list of the planetary and annular 
nebule of the Southern Hemisphere, which have been detected by Sir 
J. Herschel in his sweeps. They are arranged in order of R.A., and 
numbered. Among these, several are somewhat elongated, and offer 
the appearance of being double. One of them (No. 7) is of a fine 
blue colour, and being particularly well defined, has exactly the aspect 
of a blue planet. No. 4 is a very bright and considerably large elliptic 
disc of uniform light, on which, but excentric, is placed a pretty large 
star. Several are very small; No. 15, in particular, is not more than 
3" or 4’ in diameter. Many of them occur in crowded parts of the 
Milky Way, with not fewer than 80 or 100 stars in the field of view at 
the same time.—The drawings above mentioned were copies of much 
more elaborate originals, and were produced merely as specimens se- 
lected from a greater collection, illustrative of three of the most singu- 
larly constituted nebule in the Southern Hemisphere, viz. 6 Orionis, 
n Argus, and 30 Doradus. Sir John Herschel gave several examples 
from the voluminous tables of the manner of registering the observa- 
tions respecting each star, double star, clusters, and nebule; he also 
explained how, by the contrivance of a small achromatic collimator 
placed inside of his great sweeping telescope, he was able to obtain 
nearly the same precision in his observations as was to be had in fixed 


TRANSACTIONS OF THE SECTIONS. 19 


observatories: although, from the ropes and wooden frame with which 
it was mounted, it was subjected to great hygrometic and pyrometric 
changes of form and position. These changes, however, by equally 
affecting the cross of the collimator, and the object itself, were readily 
detected and corrected. 


On Halley's Comet. By Sir Joun F. W. Herscuet, Bart. 
FERS. §¢. 


“ One of the most interesting series of observations of a miscella- 
neous kind I had to make at the Cape of Good Hope, was that of 
Halley’s comet.—I saw the comet for the first time after its perihelion 
passage on the night of the 25th of January. Mr. Maclear saw it on 
the 24th. From this time we both observed it regularly. Its appear- 
ance was that of a round, well-defined disk, having near its centre a 
very small bright object exactly like a small comet, and surrounded by 
a faint nebula. This nebula in two or three more nights was absorbed 
into the disc, and disappeared entirely. Meanwhile, the disc itself di- 
lated with extraordinary rapidity; and by examining its diameter at 
every favourable opportunity, and laying down the measures by a pro- 
jected curve, I found the curve to be very nearly a straight line, indi- 
cating a uniform rate of increase; and by tracing back this line to its 
intersection with the axis, I was led, at the time, to this very singular 
conclusion, viz. that on the 21st of January, at 2h. p.m., the disc must 
have been a point—or ought to have had no magnitude at all! in other 
words, at that precise epoch some very remarkable change in the phy- 
sical condition of the comet must have commenced. So far all was 
speculation. But in entire harmony with it is the following fact 
communicated to me no longer ago than last month by the venerable 
Olbers, whom I visited in my passage through Bremen, and who was 
so good as to show me a letter he had just received from M. Bogus- 
lawski, Professor of Astronomy at Breslau, in which he states that he 
had actually procured an observation of that comet on the night of the 
2lst of January. In that observation it appeared as a star of the sixth 
magnitude—a bright concentrated point, which showed no disc, with 
a magnifying power of 140! And that it actually was the comet, and 
no star, he satisfied himself, by turning his telescope the next night on 
that point where he had seen it. It was gone! Moreover, he had 
taken care to secure, by actual observation, the place of the star he 
observed ; that place agreed to exact precision with his computation ; 
that star was the comet, in short. Now, I think this observation every 
way remarkable. First, it is remarkable for the fact, that M. Bogus- 
lawski was able to observe it at all on the 2ist. This could not have 
been done, had he not been able to direct his telescope point blank on 
the spot, by calculation, since it would have been impossible in any 
other way to have known it from a star. And, in fact, it was this 
very thing which caused Mr. Maclear and myself to miss procuring 
earlier observations. I am sure that I must often have swept, with a 
night-glass, over the very spot where it stood in the mornings before 

c 2 


20 EIGHTH REPORT—1838. 


sunrise; and never was astonishment greater than mine at seeing it 
riding high in the sky, broadly visible to the naked eye, when pointed 
out to me by a notice from Mr. Maclear, who saw it with no less 
amazement on the 24th. The next remarkable feature is the enor- 
mously rapid rate of dilatation of the dise and the absorption into it of 
all trace of the surrounding nebula. Another, is the interior cometic 
nucleus. All these phenomena, while they contradict every other hy- 


pothesis that has ever been advanced, so far as I can see, are quite in 


accordance with a theory on the subject which I suggested on the oe- 
casion of some observations of Biela’s comet,—a theory which sets out 
from the analogy of the precipitation of mists and dews from a state of 
transparent vapour on the abstraction cf heat. It appears to me that 
the nucleus and grosser parts of the comet must have been entirely 
evaporated during its perihelion, and reprecipitated during its recess 
from the sun, as it came into a colder region; and that the first mo- 
ment of this precipitation was precisely that which I have pointed out 
as the limit of the existence of the disc, viz. on the 21st of January, at 
2h. p.M., or perhaps an hour or two later.” 


On the Difference of Longitude between London and Edinburgh. By 
Str Tuomas M. Briszane, F.R.S. 

Having observed the surprising accuracy with which the difference 
of longitudes of London and Paris had been obtained by Mr. Dent’s 
chronometers, Sir Thomas Brisbane applied to that gentleman, who, 
with great liberality, furnished for the purpose of the experiments 
twelve of his valuable chronometers. With these, the differences of 
longitude of London, Edinburgh, and Mukerstoun were taken; and by 
a mean of all the observations taken in going to the latter station and 
in returning, they were found to differ only by five one-hundredths of 
asecond. He exhibited to the Section the following table. 


Difference of Longitudes. 


Chrono- 


meters. Mean of 
Going. Returning. Going and 
Returning. 
2 mM. iS. m. S&S. m. S&. 
A 2 40.14 | 2 39.10 | 2 39.62 | —0.16 Minimum difference. 
B ses O9L08) | esc OOKG0) Peco’ OOO” 
C -- 39.85 |... 39.52 |... 39.68 
D -. 39.68 |... 39:96 |... 39.82 
E -- 39.66 |... 39.89 |... 39.78 
F -» 40:33 |a.. 39:92 | 3.2 40:12 
G + 39.48 |... 39.95 |... 39.72 | +0.34 Maximum difference. 
H ITO ewe 40135 ecey G9L96 
I -- 39.99 |... 39.59 |... 39.79 
K -. 40.03 |... 39.68 |... 39.86 
L SUELO Alfacte OUcsa nese OOS: 
M - 39.52 |... 39.75 |... 39.64 
Means | 2 39.83 | 2 39.74 | 2 39.78 


——$—$—$<—$—$—————— eee et 


TRANSACTIONS OF THE SECTIONS. 21 


On the means adopted for correcting the Local Magnetic Action of the 
Compass in Iron Steam-ships By G. B. Airy, F.R.S., Astrono- 
mer Royal. (In a letter to Rev. Prof. Whewell.) 


In this communication, the author states some of the principal results 
of a series of observations and experiments (made at the request of the 
Admiralty) for correcting the local magnetic action on the compass in 
the steam-ship the Rainbow. 

“ The compass was placed in four different stations near the deck, 
and in four stations about 13 feet above the deck ; and for each of these 
the ship was turned round, and the disturbance observed in many posi- 
tions. The disturbances even at the upper stations were great, but at 
all the lower stations they were very great, and at the station next the 
stern they were enormous. The whole amount there was 100° (from 
— 50° to + 50°); and on one occasion, in turning the vessel about 
94°, the needle moved 74° in the opposite direction. I should have 
perhaps found some difficulty in reducing these to laws if I had not 
made some observations of the horizontal intensity at the four lower 
stations in different positions of the ship. From these I was able to 
infer the separate amounts of disturbance due to the permanent mag- 
netism of the ship and to the induced magnetism, and to construct cor- 
rectors. These correctors I tried yesterday, completely at the sternmost 
station, and imperfectly at two others. The correction at the sternmost 
station was (speaking generally) complete ; the extreme of deviation, 
which formerly exceeded 100°, did not, with the corrector, exceed 1° 
At the other stations I had not leisure to adjust the apparatus: but I 
fully expect to-morrow to produce the same accordance atthem. This 
result is, I should think, important in a practical sense. Some theo- 
retical results which I did not anticipate are also obtained. At the stern 
position, the disturbance is produced almost entirely by the permanent 
magnetism, the inductive magnetism producing only s+ of the whole 
effect. Going towards the head, the effect of the permanent magnetism 
diminishes, and that of the inductive magnetism increases, till the latter 
produces about 4 of the whole effect. The resolved part of the per- 
manent magnetism transverse to the ship varies little (increasing 
somewhat towards the head): the part longitudinal to the ship decreases 
rapidly from the stern to the head (where it is less than the transverse 
part). * “G, B. Arry.” 


A Statement of the Progress made towards developing the Law of 
Storms ; and of what scems further desirable to be done, to ad- 
vance our knowledge of the subject. By Lieut.-Colonel Reiv, Royal 
Engineers. 


Having been ordered, in the course of military duty, to the West 
Indies in 1831, the author arrived at Barbadoes immediately after the 


* A memoir containing the full investigation of this subject has been presented to 
the Royal Society, and is expected to appear in the forthcoming volume of the Philo- 
sophical Transactions. 


eee 


22 EIGHTH REPORT—1838. 


great hurricane of that year, which, in the short space of seven hours, 
killed upwards of 1400 persons on that island alone. He was for two 
years and a half daily employed as an engineer officer, amidst the 
ruined buildings, and was thus naturally led to the consideration of the 
phenomena of hurricanes, and earnestly sought for every species of 
information which could give a clue to explain them. 

The first reasonable explanation met with was given in a small 
pamphlet, extracted from the American Journal of Science, written by 
W. C. Redfield, of New York. 

The gradual progress made in our acquaintance with the subject of 
storms is not uninteresting. The north-east storms on the coast of 
America had attracted the attention of Franklin. One of these storms 
preventing his observing an eclipse of the moon in Philadelphia, he 
was much surprised to find that the eclipse had been visible at Boston, 
which town is north-east of Philadelphia: this was a circumstance not 
to be lost on such an inquiring mind as Franklin’s. By examination 
he ascertained that this north-east storm came from the south-west ; but 
he died before he had made the next step in this investigation. 

Colonel Capper, of the East India Company’s Service, after having 
studied meteorological subjects for twenty years in the Madras terri- 
tory, wrote a work on the winds and monsoons in 1801. He states his 
belief that hurricanes will be found to be great whirlwinds, and that 
the place of a ship in these whirlwinds may be ascertained; for, the 
nearer to the vortex, the faster will the wind veer; and subsequent 
inquiries prove that Colonel Capper was right in this opinion. 

Mr. Redfield, following up the observations of Franklin, probably 
without knowing those of Colonel Capper, ascertained that whilst the 
north-east storms were blowing on the shore of America, the wind, 
with equal violence, was blowing a south-west storm in the Atlantic. 
Tracking Franklin’s storms from the southward, he found throughout 
their course that the wind on opposite sides blew in opposite directions ; 
and that, in fact, they were progressive whirlwinds, their manner of re- 
volving being always in the same direction. By combining observations 
on the barometer with the progressive movement of storms, Mr. Red- 
field appears to have given the first satisfactory explanation of its rise 
and fall in stormy weather, and Colonel Reid’s observations confirm his 
views. 

The first step taken by the author, in furtherance of this inquiry, 
was to project maps on a large scale, in order to lay down Mr. Red- 
field’s observations, and thus to be better able to form a judgment on 
the mode of action of the atmosphere. 

These maps, which have now been engraved for publication in a 
separate work, were laid before the Association. The wind is marked 
on them by arrows. On the right-hand side of the circles the arrows 
will be observed to be flying from the south ; on the left-hand, coming 
back from the north. 

The field of inquiry which this opens can be but merely indicated 
here ; to proceed in a satisfactory manner with the inquiry, the study 
being a new one, requires that the proofs be exhibited step by step. 


TRANSACTIONS OF THE SECTIONS. 93 


The inferences drawn from the facts appear very important, and the 
further pursuit of the investigation well deserving attention. 

The manner in which Colonel Reid has followed it up has been by 
procuring the actual log-books of ships, and combining their inform- 
ation with what could be obtained on land, so as to compare simulta- 
neous observations over extended tracts. On Chart VII. were repre- 
sented thirty-five ships in the same storm, the tracks of several cross- 
ing the storm’s path, and the wind as reported by the ships corroborated 
by the reports from the land. 

The observations of ships possess this great advantage for meteoro- 
logical research, that merchant log-books report the weather every two 
hours, and ships of war have hourly observations always kept up. 

After tracing a variety of storms in north latitudes, the author was 
struck with the apparent regularity with which they appear to pass to 
the North Pole; and was thence led to suppose, from analogy, that 
storms in south latitude would be found to revolve in a precisely con- 
trary direction to that which they take in the northern hemisphere. 
Earnestly seeking for facts to ascertain if this were really the case, he 
had obtained much information to confirm the truth of the opinion 
before he was at all aware that Mr. Redfield had conjectured the same 
thing, without, however, having himself traced any storms in south 
latitude. Chart VIII. represents the course of a storm productive of 
very disastrous consequences, encountered by the East India fleet, under 
convoy, in 1809, and it is strikingly illustrative of this important fact. 

If storms obey fixed laws, and we can ascertain what those laws are, 
the knowledge of them must be highly useful to navigation; but to 
apply the principles practically, requires that seamen should study and 
understand them. The problem so long desired to be solved, viz. on 
which side to lay to a ship in a storm, Colonel Reid trusts is now ex- 
plained. ” 

By watching the mode of veering of the wind, the portion of a storm 
into which a ship is falling may be ascertained. The object required 
is, that the wind, in veering, shall veer aft instead of ahead ; and that 
a vessel shall come up instead of having to break off. To accomplish 
this the ship must be laid on opposite tacks, on opposite sides of a 
storm. but the limits of this notice render it impossible to attempt an 
explanation in detail. 

The researches which have been carried into the southern hemi- 
sphere afford a very interesting explanation of the observations of 
Capt. King, in his sailing directions for the southern extremity of Ame- 


_ rica, namely, that the rise and fall of the barometer in storms corre- 


spond with the rise and fall in high northern latitudes; east and west 
remaining the same, but north and south changing places. 

Five connected storms which occurred in 1837, and followed each 
other in close succession, possess an interest altogether new, for they 
give us a clue to explain the variable winds. Since these whirlwinds 
revolve by an invariable law, and always in the same direction, every 
new storm changes the wind. Thus the hurricane of the middle of 
August 1837, traced on Chart VII., had hardly passed towards the 


24 EIGHTH REPORT—1838. 


Azores, with the wind in the southern portion of it blowing violently 
at the west, when another storm, coming from the south, and bringing 
up the ship Castries with it, at the rate of seven or eight knots an hour, 
reversed the wind to east. 

The storms expanding in size, and diminishing in force, as they pro- 
ceed towards the poles, and the meridians at the same time approaching 
each other, gales become huddled together; and hence, apparently, 
the true cause of the very complicated nature of the winds in the lati- 
tude of our own country. 

Since great storms in high latitudes often extend over a circular 
space of 1000 miles, the length and breadth of the British Islands afford 
far too limited a sphere for their study. Nations should unite to study 
the laws of atmospheric changes. By exchanging the observations 
made at the light-houses of different countries, reports would be ob- 
tained along the coasts of the whole civilized world. If the merchant 
log-books, instead of being destroyed, which is often the case at pre- 
sent, were preserved in depots, each great commercial port keeping 
its own, they would greatly assist in giving information, by simulta- 
neous observations on the sea and along the coast. The meteorolo- 
gical reports within the interior of different countries should, after the 
same manner, be exchanged, and we should then soon be enabled to 
trace the tracks of storms over almost the entire surface of the globe. 

(The author then alluded to certain electro-magnetic phenomena, 
which offer close analogies to the phenomena of revolving storms.) 

During his investigation of the law of storms Colonel Reid endea- 
voured also to ascertain the laws by which water-spouts revolve. After 
many fruitless researches, he obtained at length two satisfactory in- 
stances, one of which is from Captain Beechey. It is remarkable, that 
in these two instances, which occur in opposite hemispheres, the revo- 
lations are in opposite directions, but both in the contrary direction 
to great storms. The double cones in water-spouts, one pointing up- 
wards from the sea, the other downwards from the clouds, peculiarly 
mark these phenomena, and we ought to observe whether the cloud 
above, and the sea below, revolve in the same directions with each other. 
To ascertain their electrical state would be also highly interesting, and 
this perhaps may not be impracticable, for the great hydrographer and 
navigator Horsburgh actually put his ship through small phenomena of 
this description, in order to examine them. 

Colonel Keid notices the apparent accordance of the force of storms 
with the law of magnetic intensity, as exhibited by Major Sabine’s re- 
port to the Association. It is frequently remarked, with astonishment, 
that no storms oecur at St. Helena; the degree of magnetic intensity 
there is nearly the lowest yet ascertained on the globe. Major Sabine’s 
isodynamic lines to express less than unity are only marked there, and 
they appear, as it were, to mark the true Pacific Ocean of the world. 
The lines of greatest intensity, on the contrary, seem to correspond 
with the localities of typhoons and hurricanes, for we find the meridian 
of the American Magnetic Pole passing not far from the Caribbean 
Sea, and that of the Siberian pole through the China Sea. 


ay 


- >. 
ae: 


TRANSACTIONS OF THE SECTIONS. 25 


The author then notices the performance of Mr. Whewell’s and Mr. 
Osler’s anemometers, and observes, “It is very desirable that these 
beautiful instruments should be placed beyond the limits of our own 
island, particularly in the West Indies and at the Cape of Good Hope, 
where they may measure the force of such a gale as no canvass can 
withstand ; that which forces a ship to bare poles. 

“It is not only to measure the wind’s greatest force that it is desi- 
rable these anemometers should be multiplied and placed in different 
localities, but that we may try, through their means, to learn something 
more of the gusts and squalls which always occur during storms.” 


Note on the Effect of Deflected Currents of Air on the Quantity of 
fain collected by a Rain-gauge. By Professor A. D. Bacue, of 
Philadelphia. 


The experiments referred to grew out of a report made at the request 
of the British Association, on the quantity of rain collected at different 
heights, which was presented at the Cambridge meeting of the Associa- 
tion by Professor Phillips and Mr. William Gray, jun. Professor Rogers 
was then present, and at his instance the author commenced a series of 
observations about the close of the year 1833. Philadelphia, from the 
extent of the plain on which it stands, is a good locality for such a pur- 
pose. The observations were at first made by gauges placed at three 
different heights. One of these stations was the top of a tower for- 
merly used for making shot. The height of the tower is 162 feet. A 
second was near the ground within the inclosure about the tower, and 
the intermediate one was the roof of the university. The author’s at- 
tention was ultimately fixed upon the fact that the effect of eddy winds 
upon the phenomena observed, was by no means a secondary one in 
amount, and that he could not hope to deduce a law, nor to thruw any 
light on the nature of the phenomena, until this disturbing action was 
got rid of. He has therefore thought that it might be useful to those 
who may undertake similar experiments, to submit some of the evi- 


_ dence of the effects which he attributes to deflected currents of air. 


The observations on this point were chiefly made at the upper station, 
on the top of the tower. The tower is square in its section, and the 
alternate sides are nearly parallel and perpendicular to the meridian. 
At the roof the horizontal section is about twelve feet on a side, and a 
parapet wall, cut like a battlement, surrounds it. At first, one gauge 
was placed at the N.W. angle of the tower, rising about six inches 
above the parapet wall; subsequently, a gauge for collecting snow was 
placed at the S.W. angle; and ultimately, four gauges, besides the ori- 
ginal one, were placed at the four corners of the tower, upon the para- 
pet wall, above which they rose about ten inches. The rain gauges 
consisted of an inverted cone, with a cylindrical rim, about five inches 
in diameter, attached to the base, and a small aperture near the vertex ; 
this fastened tightly upon a vessel serving as a reservoir. The snow 
gauges were frustums of upright cones, the upper section being nearly 


s te 


26 EIGHTH REPORT—1838. 


four inches in diameter. The water was measured in a glass tube, in 
which one-thousandth of an inch of rain fallen was measurable. When 
the snow gauges became useless, they were used as rain gauges, by at- 
taching a funnel to them, or were finally replaced by rain gauges simi- 
lar to those described. The quantity of water collected was measured 
after each rain, and the direction of the wind during the rain was fre- 
quently noted. To illustrate the effects which are attributed to cur--_ 
rents of air deflected by the tower, Professor Bache has taken from the 
journal of the latter months of observation the records of the quanti- 
ties of rain collected by four similar gauges, placed at the four angles 
of the tower, under different circumstances as to the direction of the 
wind. These are selected so as to present, as far as possible, a case of 
rain with each principal direction of the wind. 


Angle of the Tower at which the | Relative Quantities at 


Date, Wind. Gauge was placed. different Angles, 
N.E. S.E. S.W. | N.W. | N.E.| S.E.| S.W. N.W. 
Rain in Inches. 

July 26 N. 0-552 | 0-760 | 0°749 | 0°583 | 1:00) 1°37) 1°35) 1-05 
Aug. 6 N.E. 0°311 | 0°378 | 0°607 | 0°491 | 1-00) 1°21} 2:08) 1°58 
July 15] E.& N. by E. | 0°912 | 1-398 | 1-868 | 1°715 | 1-60} 1-53) 2:04) 1-88 
April 13 | N.E., S.E., SW. | 1°316 | 1°186 | 1°568 | 1-670 | 1-10} 1-00} 1-31) 1°40 
Aug. 26 S. & $.S.E. 0°407 | 0°253 | 0-241 | 0°391 | 1-68) 1 04) 1-00) 1-62 
June 19 | W.S.W. & S.S.W. | 0°389 | 0°285 | 0°252 | 0°198 | 1-96] 1-43) 1-26) 1-00 
Sept. 1 W. 0°302 | 0°328 | 0°202 | 07141 | 2-14] 2-32) 1-43) 1-00 
Sept. 5 W.N.W., N. 0°638 | 0°731 | 0°429 | 0-679 | 1-48} 1-70) 1-00) 1-58 


On this table the author remarks,—1. That it illustrates the very 
great differences between the quantities of rain collected at the different 
angles of the tower. In one extreme case the quantity collected at the 
S.E. angle was 23 times that at the N.W. angle. 2. That, in general, 
the gauges to leeward received more rain than those to windward. 
Thus, with a north wind, the gauges at the S.E. and S.W. angles re- 
ceived more rain than those at the N.E. and N.W. angles. With a 
N.E. wind the gauge at the S.W. corner of the tower received the most 
rain. In the case given in the table, the ratio of the quantities is nearly 
2-1 to 1. With an easterly wind the N.E. and S.E. gauges received 
less than the N.W. and S.W. With a south-easterly wind the S.E. 
gauge received the least, and the N.W. the greatest quantity of rain, 
and so on, nearly in the order stated in the general remark. 3. As the 
more considerable rains accompany certain winds, it is not to be ex- 
pected that averages of any number of observations exposed to such 
errors will lead to an accurate result of the quantity of rain falling at 
a certain height above the surface. In fact, the averages froma period 
of nine months do not agree nearly so well as those from the selected 
specimens in the table. These give ratios of 1, 1:19, 1°24, and 1°20, 


TRANSACTIONS OF THE SECTIONS. 27 


for the quantities at the different angles ; while the former-mentioned 
averages at the N.E. and S.W. angles are nearly as one to one and a half. 
4. The connexion between the direction of the wind and these effects 
is easily made out ; but without an anemometer this is not possible for 
that of the force. “I have found, however,” observes the author, 
“in the case of the N.E. wind, which most frequently attends our 
greatest rains, considerable differences, even with a moderate wind 
amounting, for example, as high as a ratio of one and a half to one. 
Having seen that I could not hope for accurate results by these ar- 
rangements, I next tried the effect of elevating the gauge upon a high 
pole, as was done by Professor Phillips and Mr. Gray with the gauge 
on the top of York Minster. The differences that appeared in this case 
were very trifling indeed: thus, on the 26th of August, when the N.E. 
and S.W. gauges upon the parapet wall gave quantities in the ratio of 
1 to 1°68, those six feet above the parapet gave 1 to 1:08; with a more 
moderate wind the quanties were more nearly the same.” 

The author proposes to resume this inquiry with reference to the ge- 
neral question on his return to America. (See Reports of the Asso- 
ciation, Vols. II. III. IV. for the researches conducted during three years 
at York.) 


On the Variations in the Quantity of Rain which falls in different 
Parts of the Earth. By Witu1am Smita, LL.D. 


Effects so very local, as shown by rain-gauges, at short distances 
apart in our own island, must arise, Dr. Smith imagines, from local 
causes. The general remark, that much less rain falls on the eastern 
than on the western side of England, stands confirmed by the tables ; 
and as at Edinburgh there fall only 22 inches, and in Dublin 22-2, it 
seems likely to hold in other parts. The local variations in the quan- 


tities of rain in England are, however, very great ; and in a short table 


of sixteen local averages, from 67 inches at Keswick, down to 22°7 
at South Lambeth, the half of them on the western side of England 
are by far the highest; but the comparatively small quantities of rain 
at Bristol and Chatsworth not according with this generalization, and one 
place on the eastern coast being even higher than these, and higher than 
Liverpool, this generalization, Dr. Smith conceived, required to be 
modified. More local causes seemed requisite to account for the ob- 
served facts; and Dr. Smith imagined that they are to be found in the 
nature of the surrounding country, that is, in the physical differences of 
the vicinity of each place, and not altogether in the track of the most 
rainy winds. 

In confirmation of this opinion, meteorological registers were quoted 
to show that, although westerly and southerly winds blow at London 
101 days more than the drier easterly or northerly winds, yet London 
is the least rainy place in Britain, except Edinburgh, which averages 
seven tenths lower than South Lambeth. The cause of much rain de- 
pends not, therefore, he conceived, wholly on the prevalence of westerly 


28 EIGHTH REPORT—1838. 


winds ; but, in part at least, on the humidity of the neighbouring re- 
gions. The westerly winds, before they reach London, pass over a great 
extent of high and dry land; and, consequently, there’is, at the level of 
the chalk hills (600 to 800 feet high), a dry atmosphere over London. 
Bristol, having 52 inches less rain than Liverpool, and nearly seven 
inches less than Manchester, is surrounded by high and dry hills of 
limestone; and Chatsworth, having 4 inches less than Bristol, is also,. 
except on the eastern side, surrounded by very high and dry hills. Dr. © 
Smith illustrated this part of his argument by reference to other places. 
Manchester, having 36:1 inches, is not far west of the high and damp 
hills of millstone grit, which here form the summit ridge of England ; 
but about Lancaster, the width of wet-topped hills increases, so that 
vapour from these, the southern swampy shore, and of the tides and 
sands of Morecambe bay, may account for 39°7 at Lancaster. Townly, 
high, and in the vicinity of bog-topped hills, has 41-5; Grisdale, West- 
morland, 52°3; and Kendal 539; the latter, perhaps, partly from the 
hills, and partly from Lancaster sands and adjacent marshes; but Kes- 
wick averages 67 inches. This, perhaps, is the greatest quantity of rain 
which falls at any one place in England, and is perliaps to be accounted 
for by the peculiar situation of Keswick, at the meeting of four valleys, 
which intersect a group of very high mountains, and near to swampy 
ground, and large pieces of water, on which the winds have great in- 
fluence in raising vapour, which the cold sides of the mountains rapidly 
condense. These hill tops, as well as those of millstone grit, have a 
covering of peat, which holds water like a sponge. 


Notice of a Brine Spring emitting Carbonic Acid Gas. By Professor 
Forses, #.R.S. (dn a Letter to Prof. Phillips.) 


The letter of Prof. Forbes noticed a remarkable spring, about a mile 
from Kissingen, Bavaria, which had occupied much of his attention, and 
of which he will probably at a future time draw up a more detailed ac- 
count *. It is a brine spring, having 3 per cent. of salt, rising in a bore, 
325 Bavarian feet deep, in red sandstone; but the author understands 
that the water flows at about 200 feet in depth. Its temperature is never 
less than 65°; the mean temperature of springs near being only 50° to 
52°. It discharges carbonic acid gas in volumes almost unexampled, 
keeping the water, in a shaft eight feet diameter, in a state resembling 

turbulent ebullition. The enormous supply of gas has led to its use in 
gas baths, for which purpose it is carried off by a tube connected with 
a huge inverted funnel, which rests upon the water. J¢ contains scarcely 
a trace of nitrogen. It is conducted into chambers properly prepared, 
and thence into baths, in which it lies by its weight, and is used as water 
would be. But the most remarkable feature still remains to be noticed. 
About five or six times a day the discharge of gas suddenly stops; ina 
few seconds the surface of the well is calm. The flow of water, amount- 


* This account has been published in the Edinburgh Philosophical Journal, 1839. 


TRANSACTIONS OF THE SECTIONS. 29 


ing to forty cubic feet per minute, also stops, or rather becomes negative, 
for the water recedes in the shaft even when the pumps commonly used 
to extract the brine «lo not work, and the water subsides during fifteen 
or twenty minutes. It then Hows again, the water appearing first and 
suddenly, the gas gradually increasing in quantity, till, after three quar- 
ters of an hour, the shaft is full as at first. The state of greatest dis- 
charge continues with little variation for three or four hours, but by no 
means with absolute regularity. It is also affected by various circum- 
stances, apparently extraneous ; this has gone on with little variation 
since the bore was made in 1822. Within a short distance is a bore 554 
Bavarian feet deep, which exhibits somewhat similar phenomena. Alto- 
gether, Prof. Forbes considers that the salt spring at Kissingen is the 
most singular phenomenon of its kind in Europe except the Geysers. 


On the Climate of North America. By Dr. Davuseny, Professor of 
Chemistry and Botany, Oxford. 


The principal object of this communication was to invite the atten- 
tion of meteorologists to the present state of our knowledge with 
respect to the climate of the North American continent. With this 
view the professor laid before the Section the following general table, 
which comprehends all the observations on this subject that he had been 
able to collect during his late visit to the United States and Canada. 

The best observations made in Canada are those of Mr. M‘Cord, of 
Montreal, who has procured from England excellent instruments, and 
has spared no pains in arriving at accurate results. 

From his statement, it would seem as if there had been a sensible 
deterioration in the climate of that part of Canada since 1830, for the 


mean of that year was .........-.. 47-8 
OL TSS Warr. a2 46°38 
S32 hie bee 447 
Ise) ey ote 44°8 
183402. -/'. 45°0 
1835 ...... 42°9 
ASS 2-5 28 40°43 
1837 41°22 


And a tendency in the same direction may perhaps be detected in the 
observations recorded at Fort Diamond, above Quebec. 


Temp. 
For in 1830 ...... 41:00 Fahr. 
Bet HEM < ge nie OOO 35 
By OOS as aos 35°50 sy, 
Saal Sie 1S)) eee - 36°91 |; 
ah iss cr 36°87, 
Se ESS OMe sk: 33°41 ,, 
ME SOON! ss sc 35°82, 


30 EIGHTH REPORT—1838. 


It would be interesting to find out, whether this reduction of tem- 
perature indicated a permanent change in the climate of Canada, or 
whether the years noticed constitute the coldest portion of a cycle of 
longer duration, and consquently give a result below the actual mean. 
Dr. Daubeny remarks, that the position selected for meteorological 
observations at Quebec is so elevated and exposed that it does not 


fairly represent the mean temperature of the neighbourhood. In the - 


United States the best observations made are those carried on at the 
several academies in the state of New York, under the direction of the 
state government. The author has quoted a sufficient number of 
these to convey a notion of the climate of that portion of the Union, 
and the “ Annual Report of the Regents of the University of the State 
of New York” for the remainder. The mean temperature of Phila- 
delphia cannot yet be regarded as settled, though good observations 
have been carried on for the last three years by Captain Mordecai. 
These have been quoted in preference to others of longer date 
reported by Mr. J. Young, stated by him to have been deduced from 
twenty years observations, as the mean obtained by the latter (58°4) is 
so much above that of places lying to the south (Washington and 
Richmond for instance), that we are driven to suppose that the spot 
selected must have been an unsuitable one. 


_ ewe = Serre 


i Ss 


TRANSACTIONS OF THE SECTIONS. 31 


Table of the comparative Temperature of various places in the continent of 
North America, from N. Lat. 46° to 24°, compiled from various sources. 


ee) Sa} Ck ly) | se.) Ce 
so. _| @ [egies | Ee. 
s PoEs Locality and 3 = pe Bs q gs 3 ee for 
g ig gos Geographical situation. | 2 2 |2o/,88) BES gia en ais 
& |e5S¢ Sil AS Le oh ee ges ; 
aS 23} se ao 
Le =} < 
7] 7 Of 
(| E. {Cape Diamond, Que- 46-50 71-10| 330| 37-66/8 years, viz.|Mr. Watt. 
bec, Lower Canada 1829to1836 
W. |Fort Brady, near the| 46-39] 84- 5| 595 | 41-37] Not stated |Lovell’s Re- 
46th 4 Falls of St. Mary, gister, quoted 
Michigan State by Darby 
| (View of the 
L Unit. States). 
45th E. |Montreal, Lower Ca-| 45-30] 73-35]......| 44°20/8 years, viz./Mr. M‘Cord. 
nada 1830to1837 
(| W. |Fort Howard,S. extre-| 44-40) 87- 2/ 600 | 44-50] Not stated |Lovell’s Re- 
mity of Green Bay, gister, quoted 
Michigan by Darby. 
W. {Fort Snelling, near the] 44-53| 93-15] 780] 45° 0| Not stated (Ditto. 
44th junction of the St. 
Peter’s and Missis- 
sippi rivers 
- {Fort Sullivan, East-| 44-44|67-111)...... 42°44) Not stated |Ditto. 
L port, Maine 
{| E. {Dartmouth Coll. Ha-| 43-45] 72-29]...... 40° 6/2 years, viz.|VermontChro- 
nover, New Hamp- 1835 & 1836) nicle. 
shire 
E. |Dover, New Hamp-| 43-20] 69-12]......| 42° 8} 1 year, viz. |A. Tufts. 
shire 1836 
43rd E. |Concord, New Hamp-| 43-20] 70-29)...... 42° 4) 1 year, viz. |J. Farmer. 
shire 1836 
E. |Portsmouth, New] 43: 5} 70°46)...... 45: 8! Not stated |Mellish’s de- 
Hampshire scription. 
W. |Rochester, New York} 43-08] 77-10] 506| 47-26|5 years, viz.|Regents of 
State 1830, 33, | the Univer- 
34, 35, 36| sity of New 
York. 
[| W. |Lewiston near Buffalo, 42°50] 79-20)...... 48°35)6 years, viz.|Ditto. 
New York State 1831to1836 
W. Albany, New York) 42-39] 73-20]......| 48°56 1] years, viz.|Ditto. 
> State 1826 to 1836 
42nd E. |Cambridge, near Bos-| 42-25] 71: 0] 0 |52:36| 2 years |Humboldt on 
ton, State of Mas- Isothermal 
sachusetts lines. 
W. |Detroit, State of Mi-| 42-30) 82-50)...... 47- 4! 1 year, viz. |Mellish’s de- 
chigan 1818 scription. 


Newport —_ Harbour,| 41-30] 71-25} 0 | 51-02] Not stated Lovell. 
Rhode Island 

Council Bluffs’, above} 41-25] 95-50! 800 50°82} Not stated |Ditto. 
the mouths of Platte 

River, Missouri 


ae 


32 EIGHTH REPORT—1838. 
e o g 
eg male 
_ fees ¢ [ge |e8 | es. 
3s |FSds 2 a Sata sles ol ice toa as 
BSE Gea tne Lat ati 3 | 2 |selecs| 828 | theanncxat 
& |-3 =. 5] Geographical situation, a1 tw 1s oo Ses e annexe 
ad iZons 3 Pad) strc fetiai ts) son statement. 
a = 4 Se pre fons sag 
Ao 22lae a? 
a < 


(| E. |New York Harbour... 40-42 73°20 0 | 52°82} Not stated |Ditto. 
|| W. {Fort Columbus, near| 40-82) 80°20)...... 54° 2/1 year, 1820)Mellish. 
40th 4 Eee Pensyl- 
E. |Germantown, near] 40°03} 75: 0O)...... 52°37/10 years,viz.|R. Haines. 
Philadelphia 1819to 1828 
E. |Philadelaphia......... 39°56] 75°10) 0 | 52°52) Not stated |Humboldt, fr. 


comparing 
the observa- 
tions of Rush 


and Legare. 

DitioWeecessostcasastees|teecce cesceni| re ---| 50°67] 1836-7-8 |Captain Mor- 

39th decai, journal 
( 


of the Frank- 

lin Institute. 
E. |Baltimore.......... eeee.| 39°17] 77° 0} O | 53° 0)8 years, viz.|L. Bruntz. 
1817to1824 
W. |Cincinnati.............| 39°07| 84°50] 500] 54° 0/8 years, viz.|Drake, View o 
1806to 1813} Cincinnati. 
E. |Washington City,.....|38°50| 77: 2| 0 |57-09/8 years, viz.|Rev. R. Little. 
W 


f 1821t0 1827 
38th St. Louis, State of] 38°36] 90°40] 550|55- 2|7 years, viz.|Dr. Drake. 
Missouri 1829 to 1836 
W. |N. Harmony, Indiana} 38°11) 86°50] 340 | 56°69)3 years, viz./Dr. Tront. 
: 1826-7-8 
37th E. |Richmond, Virginia... 37°04] 77°50)...... 56°81}14 years, viz.|Chevallier. 
1824 to 1837 


34th E. . |Smithville, mouth of| 34° 0) 78° 0 | 58°88} Not stated |D. Lovell. 
Cape Fear River, 


North Carolina 
E. |Charleston, South Ca-| 32°44] 80°20) 0 | 58°80/18 years, viz.|Drayton, View 
39nd rolina 175Qto01759| of South Ca- 
rolina, 
DiGtOSs elo sp cee exeea well cgreesd|ieeseee)|nemane 60°18} Not stated |Dr. Lovell. 
W. |Natchez, State of Mis-| 31°28) 91°45] 180| 64°76} 4 years j|Dunbar. 
sissippi 
31st W.  |Jessup Cantonment,| 31°30} 94° 0} 150 | 68°31] Not stated |Dr. Lovell. 
near Sabine River, 
Louisiana 
W. |Baton Rouge, Louis-| 30°26] 91°40}..... -| 68°07] Not stated |Ditto. 
soe jana 
W. |Pensacola, W. Florida} 30°24] 87°40)...... 68°77| Not stated |Ditto. 
W. |New Orleans, Louis-| 29°57/90- 8]......| 66° 0/1 year, viz. |Professor 
jana 1836 Barton. 
29th E. |St. Augustine, E.coast] 29°50) 81°50] 0 | 72°23] Not stated |Dr. Lovell. 
of Florida 


24th E. |Key, West Florida...| 24°33] 82°20) 0 | 76° 6/6 years, viz.|Whitehead, 
; 1830to 1835} collector o: 


customs. 


phe 


TRANSACTIONS OF THE SECTIONS. 33 


On the Helm Wind of Crossfell. By the Rev. J. WATSON. 


Helm Wind is a local name of uncertain origin, but generally sup- 
posed to be derived from the cloud that, like a cap or helmet, is often 
seen on the tops of the mountains. It is specially applied to a very violent 
wind, blowing frequently from some easterly point of the compass, but 
mostly due east, at the west side of the mountains known by the name 
of the Crossfell range, and confined both in length and breadth to the 
space contained between the Helm and Helm Bar, hereafter described. 
Along the top ridge of the mountains, and extending from three or 
four to sixteen or eighteen miles each way, north and south, from the 
highest point, is often seen a large long roll of clouds; the western 
front clearly defined and quite separated from any other cloud on that 
side; it is at times above the mountain, sometimes rests on its top, but 
most frequently descends a considerable way down its side ; this is called 
the Helm. In opposition to this, and at a variable distance towards 
the west, is another cloud with its eastern edge as clearly defined as 
the Helm, and at the same height: this is called the Bar or Burr; the - 
space between the Helm and the Bar is the limit of the wind. The 
distance between the Helm and Bar varies as the Bar advances or 


_recedes from the Helm; this is sometimes not more than half a mile, 


sometimes three or four miles, and occasionally the Bar seems to 
coincide with the horizon, or it disperses and there is zo Bar, and then 
there is a general east wind extending over all the country westward. 
However violent the wind be between the Helm and the Bar, it extends 
no farther; on the west side of the Bar there is either no wind or it 
blows in a contrary direction, that is, from the west, or from various 
points in sudden and strong gusts, when the Bar advances so far as to 
unite with the Helm; if the Bar disperses, the wind ceases. Neither the 
Helm nor Bar are separate or detached clouds, but may be rather said 
to be the bold, clearly defined fronts of bodies of clouds extending east- 
ward behind the Helm, and westward from the Bar. The clouds forming 
the Helm and Bar cannot perhaps strictly be said to be-parallel; the 
ope®# space between them may rather be called a very flat ellipse, 
in which the transverse diameter varies from eight or ten to twenty-five 
or thirty miles, and the conjugate from half a mile to four or five miles : 
they appear always united at the ends. 

This wind is very irregular, but most frequent from the end of Sep- 
tember to the month of May; it seldom occurs in the summer months ; 
there was one this year, 1838, on the 2nd of July, and there have been 
more in the last two years than in the preceding six. Sometimes, 
when the atmosphere is quite settled, not a breath of wind stirring, 
and hardly a cloud to be seen, a small but well-known cloud appears 
on the summit, extends itself to the north and south—the “‘ Helm is 
on,” and in a few minutes blowing furiously, sufficient to break trees, 
overthrow stacks of grain, throw a person from his horse, or overturn 
a horse and cart. The Helm at times seems violently agitated, and on 
ascending the fell and entering it there is little wind, and this some- 
times not in the direction of the wind below: one may, in fact, be in 

VOL. VII. 1838. D 


(Peed 


34 EIGHTH REPORT—1838. 


the Helm for a whole day without being aware of the wind on the west. 
The Helm appears sometimes to run or pour off from the highest 
part, each way towards the north and south points of the junction of 
the Helm and Bar, and there to be piled up in great masses; occa- 
sionally a Helm forms and goes off without a blast. The open space 
between the Helm and Bar is clear of clouds, with the exception of small 
pieces breaking off now and then from the Helm and driving rapidly 
over to the Bar ; through this open space is often seen a higher stratum 
of clouds quite at rest. 

Most mountainous countries, particularly where the mountains ter- 
minate abruptly, seem liable to sudden gusts of wind, such as oceur at 
the Cape of Good Hope, in Switzerland, and among the lakes in our 
own country; but the Helm wind differs from all in respect to the Bar, 
and that within the space described it blows continually ; it has been 
known to blow for nine days together, the Bar advancing or receding, 
or continuing stationary for a day. When heard and felt for the first 
time it does not seem so very extraordinary; but when we find it 
blowing and roaring morning, noon, and night, for days together, it 
makes a strong impression on the mind, and we are compelled to ac- 
knowledge that it is one of the most singular phenomena of meteorology. 
Its sound is peculiar, and when once known is easily distinguished from 
that of ordinary winds; it cannot be heard more than three or four 
miles beyond its limit, but by persons who have stood within the wind 
or near it, it has been compared to the noise made by the sea in a vio- 
lent storm, or that of a large cotton mill when all the machinery is 
going. It is seldom accompanied by rain within the open space, and 
never continues long after it begins to rain heavily; in spring, it is 
most frequent after rain. The country subject to it is very healthy, 
but the wind does great injury to vegetation, as it batters the grain, 
grass, and the leaves of trees till they are quite black. Various hypo- 
theses have been suggested to account for this phenomenon; one of 
the most plausible assumes that the air is cooled by its gradual ascent 
from the east coast, and on reaching the summit of the mountains, 
rushes with great force down the western escarpment into a lower and 
warmer region. In opposition to this it is stated, that the valley of the 
Tyne, where the Helm wind is not felt, is not much higher than that 
of the Eden ; and secondly, the wind does not extend farther west than 
where the Bar is vertical, and this is not very often so far as the Eden. 
The cause, Mr. Watson thinks, must be sought for in that region of 
the atmosphere, extending from 800 to about 5000 feet above the 
earth’s surface. : 


On the Temperatures observed in certain Mines in Cheshire. By 
Eaton Hopcxinson, Esq. 


(The results will be given hereafter in combination with the account 
of other experiments. ) 


TRANSACTIONS OF THE SECTIONS. 35 


Facts relating to the Eijfects of Temperature on the Regulators of Time- 
keepers ; and description of some recent improvements in Pendulums, 
with Observations, and Tabulated Experiments. By Epwarp JouHN 
Dent, F.RB.A.S. 


The subjects contained in Mr. Dent’s paper may be arranged under 
three heads. 

Ist. The continuation of an inquiry into the compound effect of 

. variable temperature upon the regulating machinery of Time- 
keepers, the commencement of which had been laid before the 
Association some years before. 

2nd. A description of improvements in mercurial pendulums, princi- 

pally with a view of making them portable. 

3rd. Improvements in the suspension of pendulums in general; and 

incidental remarks connected with the subject. 

In all estimates of the effect of variable temperature upon the regu- 
lating part of timekeepers, made for the purpose of ascertaining the 
necessary amount of compensation, it had generally been assumed 
that the effect was confined to an alteration of length in a part of the 
regulator. Mr. Dent, having long felt that this view of the subject was 
insufficient to account for facts which his daily practice brought be- 
fore him, at length commenced a series of experiments with a view to 
a more complete and consistent explanation of them; and, in 1833, at 
the meeting of the Association in Cambridge, he endeavoured to show 
that the effect of variable temperature upon the balance-springs of 
chronometers might be resolved into two distinct portions: viz. the 
ene, long known, which produces the variation of length; and an- 
other, which had hitherto escaped attention, affecting the elasticity of the 
spring. 

PMT. Dent afterwards extended the inquiry to the pendulums of clocks, 

and succeeded in separating and determining the respective amounts of 
effect which changes of temperature produce upon the elasticity of the 
spring and the length of the rod. The details of this subsequent in- 
quiry, with descriptions of the apparatus invented and used for the pur- 
pose, were described at length. As an illustration, the following ex- 
periment is taken from amongst many others :— 

A clock provided with a spring-pendulum, and adjusted to keep cor- 
rect time at an ordinary temperature, was found, when the temperature 
was maintained at 48° Fahr. higher, to lose twelve seconds in twenty- 
four hours. 

Mr. Dent attempts to demonstrate by experiment that eight parts 
and a half only of this difference belong to the effect of elongation in 
the rod, and the remaining one and a half are produced by a decrease 
of elasticity in the spring. 

From the epoch of the introduction of tke mercurial cistern to the 
present time, this admirable modification of the pendulum has remained 
nearly in the state in which it was left by its inventor. 

The mercurial pendulum cannot even now be filled and transported 
in a state proper to be immediately attached to a timekeeper ; conse- 

D2 


36 EIGHTI! REPORT—1838. 


quently in the case of the transport of clocks with this description of 
pendulum to great distances, either this part of the machine (which re- 
gulates the whole) must be placed in inexperienced hands, to be filled 
with mercury and to have the column adjusted to the exact length re- 
quired for compensation, or a workman must accompany the clock and 
set it in action. The expense of the latter process constitutes, gene- 
rally, a very serious objection. i 

The pendulum cistern being made of glass, is liable to fracture, and, 
on account of the risk which attends the boiling the mercury within 
it, to drive off the air, this process is never attempted. It is very pos- 
sible to give to a glass vessel, externally, a form mathematically correct, 
but the case is very different when similar accuracy is required for the 
interior. The glass cistern, therefore, never receives a perfect figure, 
and the mercurial column it contains cannot be a regular cylinder. This © 
condition, combined with the irregularity of expansion which glass is pe- 
culiarly liable to from its compound nature, renders measurement and 
calculation with regard to the column, so vague and deceptive that they 
are never employed. 

In order to meet these serious obstacles to the satisfactory and ex- 
tensive use of this valuable instrument Mr. Dent has recommended the 
substitution of cast-iron for glass in the cistern. 

Mercury and cast-iron are quite as little disposed to amalgamate as 
mercury and glass; and iron is a material, compared with glass, which 
is more simple in its nature, and more obedient to the workman. It is 
susceptible of the most perfect forms, which it will maintain with very 
little liability to alteration, and is quite proof against numerous acci- 
dents that would be fatal to glass. ‘The expansion of iron by heat being 
also uniform and well known, it is evident that, in the cast-iron cistern, 
we may have a vessel of a known, regular, and permanent figure, or, if 
not strictly permanent, one whose changes and their laws we are acquaint- 
ed with. Calculation may, therefore, be used in anticipating results, with- 
out any fear of its widely differing from experiment. 

Further,—in a cistern of cast-iron, the mercury may be boiled at any 
time. The clockmaker may do it himself when he first puts the machine 
together,—he may adjust the column,—he may then hermetically seal 
it, and despatch the pendulum to the most distant countries with the ad- 
justment so perfect that it may be instantly attached to the wheel-work 
by any workman capable of setting the clock upon its supports. If, at 
a subsequent period, minute portions of air have, from any cause, again 
mingled with the mercury, and rendered the pendulum susceptible of 
barometric changes, the air may be again driven off with the greatest 
facility, by repeating the process of boiling, without removing the mer- 
cury from the cistern. 

Mr. Dent has accompanied the introduction of cast-iron in the cistern 
with several other alterations which have all the same intention of im- 
proving this kind of pendulum. Among others, he has removed en- 
tirely the metal stirrup, or frame, which carried the cistern, and has at- 
tached the latter to the rod ;—he has prolonged the rod, and plunged 
it into the mercury, nearly to the bottom of the cistern ;—a condition evi- 


TRANSACTIONS OF THE SECTIONS. 37 


dently favourable to uniformity of temperature in the rod and mercury, 
&e. &e. 

All strain or warp of the spring, in the final suspension of the pendu- 
lum, can be avoided. Tke pendulum being first suspended freely, is 
left until; by the cessation of its action, it arrives at its own line of rest 
in every direction, particularly in that which passes through the plane of 
the spring. The fixing-piece is then brought to it and the whole per- 
manently attached together. 

The line of the flexure of the spring can be determined and preserved. 
Usually, the exact position of this line is, within certain limits, left to’ 
accident, and is, from several causes, continually changing its position ; 
consequently, the pendulum is simultaneously varying in length. Er- 
rors in rate, often attributed to other causes, are the necessary conse- 
quence. 


Notice of a cheap and portable Barometrical Instrument proposed for 
the use of Travellers in Mountainous Districts. By Sir Joun 
Rosison, Sec. R.S.L., &e. 


The instrument is a glass tube about 0°25 of an inch in diameter, 
and about 14 inches long, with a small bulb like that of a thermometer 
blown on the upper end. The stem of the tube has been graduated by 
divisions made experimentally by the instrument-maker in the follow- 
ing manner. On a day when the barometer stood at 30 inches, and 
the temperature of the air was 62°, it was placed in the receiver of an 
air-pump, and when the rarefaction allowed the barometer of the 
pump to fall to 29 inches, the instrument was lowered until the open 
end of the tube became immersed in a cup of water, over which it had 
been suspended by a thread and wire passing through a stuffing-box. 
On allowing the atmosphere to enter the receiver, the water was pressed. 
up the tube until the density of the air corresponding to 30 inches 
was restored, and the height of the fluid was carefully marked. The 
instrument was a second time suspended in the air-pump receiver, and 
the exhaustion was repeated until the barometer gauge indicated 28 
inches, the immersion in the cup having been made as formerly ; the 
air rushed in, and the graduation of the tube corresponding to 28 
inches was accomplished. By continuing this process, the graduation 
of the stem was carried on as far as was thought requisite, (the inter- 
mediate divisions having been made in a similar manner,) when the in- 
strument became ready for use. 

Tt is obvious, that in this manner a traveller arriving at a station in 


the midst of mountains, and having with him a number of such tubes, 


would only require to send messengers to their summits with one or 
more of these tubes and a tin case containing water, for the purpose of 
giving him the means of determining their heights with considerable 
accuracy. Each messenger, carrying with him the empty glass tubes, 
is to be instructed to insert their open ends in his flask of water when 
he shall have reached the summit, and to bring them down again. 


38 EIGHTH REPORT—1838. 


Having done so, the air in the bulb and tube having become rarified 
to the tension of that on the top of the mountain, is compressed by the 
water which the increased pressure of the atmosphere as he descends 
forces into the tube, so that when he returns to the place where the 
barometer is at $0 inches, the height of the fluid will indicate the 
height at which the barometer would have stood on the summit of the 
elevation. If the barometer be not exactly at that height, a correction 
may be applied. 

If the temperature and degree of moisture of the air in the tube on 
the mountain and at the lower station were alike, no further correction 
would be requisite: but just as in the case of the barometer so with 
this instrument; for minute accuracy, a thermometer and hygrometer 
should accompany it, and be simultaneously observed, so as to permit 
the application of the usual corrections. 

In many cases precisely equal temperatures may be obtained at the 
upper and lower stations by keeping the tin case supplied with water, 
melting snow, or ice. 

In a general and rapid survey of a country, such instruments would 
possess value from their portability and cheapness. 


Tables intended to facilitate the computation of Heights by the Barometer. 
By the Rev. Tempre Curvariier, B.D., Professor of Mathematics 
in the University of Durham. 


In these tables, the correction for the temperature for the air is 
computed, so that the difference of elevation of two stations, in feet, 
is at once found by taking the difference of two numbers correspond- 
ing with the heights of the column of mercury at the two stations, and 
the mean temperatures of the air. The table is constructed for differ- 
ences of one-tenth of an inch in the barometer, the proportionate varia- 
tion for hundredths and thousandths of an inch being readily found 
by an accompanying table of proportional parts. 

A table is given for the correction for the difference of temperature 
of the mercury. 


Mr. J. S. Russell described a magnetic instrument invented by Mr. 
Watt, of Lasswade, which, according to the experience of the inventor, 
appeared to take positions corresponding to the direction of the wind. 


\ dee wen 
_ 
a? 


TRANSACTIONS OF THE SECTIONS... 


Os 
ae] 


CHEMISTRY. 


Extracts from a Letter addressed by Dr. Hare, of Philadelphia, to the 
Chemical Section of the British Associution for the Advancement of 
Science. 


“ Since July last, when I had the honour of addressing you through 
your venerable and distinguished president Dr. Dalton, I have made 
some additional observations and attained some farther results, of 
which a brief notice may, I trust, be deemed worthy of attention. 

“T have, by improvements in my process for fusing platina, suc- 
ceeded in reducing twenty-five ounces of that metal to a state so liquid, 
that the containing cavity not being sufficiently capacious, about two 
ounces overflowed it, leaving a mass of twenty three ounces. I repeat, 
that I see no difficulty in extending the power of my apparatus to the 
fusion of much larger masses. 

“ When nitric acid (or sulphuric acid and a nitrate) is employed to: 
generate ether by reaction with alcohol, there must be an excess of 
two atoms of oxygen for each atom of the hyponitrous acid which en- 
ters into combination. This excess involves not only the consumption 
of a large proportion of alcohol, but also gives rise to several acids and 
to some volatile and acrid liquids. 

“Tt occurred to me, that for the production of pure hyponitrous 
ether, a hyponitrite should be used. The result has fully realized my 
expectations. 

“ By subjecting hyponitrite of potash or soda to alcohol and diluted 
sulphuric acid, I have obtained a species of ether which differs from 
that usually known as nitrous, or nitric ether, in being sweeter to the 
taste, more bland to the smell, and in being more volatile. It boils 
below 65° F., and produces by its spontaneous evaporation a tempera- 
ture of 15°. On contact with the finger or tongue, it hisses as water 
does with red-hot iron. After being made to boil, if allowed to stand 
for some time at a temperature below its boiling point, ebullition may 
be renewed in it apparently at a temperature lower than that at which 
it had ceased. Possibly this apparent ebullition arises from the partial 
resolution of the liquid into an aériform etherial fluid, which escapes 
both during the distillation of the liquid ether and after it has ceased, 
even at a temperature below freezing. This aériform product has been 
found partially condensible by pressure into a yellow liquid, which 
when allowed to escape into the mouth or nose, produced an impression 
like that of the liquid ether. I conjecture that it consists of nitric ox- 
ide, so directed to a portion of the liquid ether as to prevent the wonted 
reaction of this gas with atmospheric oxygen. Hence it does not pro- 
duce red fumes on being mingled with air. 

“Towards the close of the ordinary process for the evolution of 
Sweet spirits of nitre, a volatile acrid liquid is created, which affects 
the eyes and nose like mustard or horse-radish. It is probable, however, 


- " wee 


40 EIGHTH REPORT—1838. 


that this is in part due to the presence of chloride of sodium, as I have 
reason to suspect the acrid liquid to be chlorocyanic_ether. 

“ Quick lime, when the new ether, as it first comes over, is distilled 
from it, becomes imbued with an essential oil, which it yields to hydric 
ether. This oil may be afterwards isolated by the spontaneous evapo- 
ration of its solvent. It has a mixed odour, partly agreeable, partly 
unpleasant. From the affinity between its odour and that of common 
nitrous ether, I suspect that it is one of the impurities which exist in 
that compound. 

« The new ether is obtained in the highest degree of purity, though 
in quantity less, by introducing the materials refrigerated by snow and 
salt into a strong, well-ground, stoppered bottle. After some time the 
ether will form a supernatant stratum, which may be separated by de- 
cantation. Any acid having a stronger affinity for the alkaline base 
than the hyponitrous acid, will of course answer to generate this ether. 
Acetic acid not only extricates, but appears to combine with it, form- 
ing apparently a hyponitro-acetic ether. 

“IT observed some years ago, that when olefiant gas is inflamed with 
an inadequate supply of oxygen, carbon is deposited, and the resulting 
gas occupies double the space of the mixture before explosion. Of 
this I conceive I have discovered the explanation. By a great number 
of experiments performed with the aid of my barometer-gauge, eudio- 
meter, and other instruments, I have ascertained, that if, during the 
explosion of the gaseous elements of water, any gaseous or volatile in- 
flammatory matter be present, instead of condensing there will be a 
permanent gas, formed by the union of the nascent water with the in- 
flammable matter. Thus, two volumes of oxygen with four of hydro- 
gen and one of olefiant gas, give six volumes of permanent gas, which 
burns like light carburetted hydrogen. The same quantity of the pure 
hydrogen and oxygen with half a volume of hydric ether, give on the 
average the same residue. One volume of the new ether, under like 
circumstances, produced five volumes of gas. 

« An analogous product is obtained when the same aqueous elements 
are inflamed in the presence of an essential oil. With oil of turpentine, 
a gas was obtained weighing per hundred cubic inches 16,5; grains, 
which is nearly half the gravity of light carburetted hydrogen. The 
gas obtained from olefiant gas, or from ether, on the average weighed, 
for the same bulk, 18,4, grains: this leaves no doubt of its being 
chiefly constituted of the water, as the olefiant gas which I used 
weighed per hundred cubic inches only 3035 grains ; if per se expanded 
into six volumes, it could have weighed only one sixth of that weight, 
or little over five grains per hundred cubic inches. 

«« With a volume of the new ether, six volumes of the mixture of 
hydrogen and oxygen gave on the average about five residual volumes. 

“The gases thus created do not contain carbonic acid, and, when ge- 
nerated from olefiant gas, appear to yield the same quantity of carbon 
and hydrogen as the gas affords before expansion. : 

« These facts point out a source of error in experiments for ana- 


~<a) 
ie 


Pe 


TRANSACTIONS OF THE SECTIONS. 4] 


lyzing gaseous mixtures by ignition with oxygen or hydrogen, in which 
the consequent condensation is appealed to as a basis for an estimate. 
It appears that the resulting water may form gaseous products with any 
volatile matter which may be present. It is in this way, as I conceive, 
that olefiant gas, when inflamed as above mentioned with a quantity of 
oxygen inadequate to saturate it, is expanded into a residual gas larger 
than that of the mixture before ignition. 
“J remain, gentlemen, with high esteem, your co-labourer, 
“ Ropert HARE.” 


Some Observations on the Foreign Substances in Iron. By Tuomas 
Tuomson, M.D. F.R.S., &c., Prof. of Chemistry, Glasgow. 


The great difference which exists between different specimens of 
iron is generally known. The best Swedish iron when compared with 
British iron, even of the best quality, in point of strength is as 4 to 3. 
A Swedish wire of a diameter of about ;4th of an inch supports a 
weight of 450 Ibs. without breaking, while the utmost weight that a 
wire of British iron of the same diameter can bear is 350 lbs. Iron 
from the mine of Dannemora in Sweden makes excellent steel; while 
British iron is so ill adapted for the purpose that it is hardly ever con- 
verted into steel, and never into good steel. Dr. Thomson thought it 
likely that their differences were owing to something in the British 
iron which injured its quality and which was wanting in Swedish iron. 
The results of some analyses made by Dr. Thomson do not entirely 
clear up the question ; but they present some important information 
on the peculiarities of iron. The following is the statement of the ex- 
periments. 

“T selected, as best suited to the object which I had in view, the 
best Dannemora iron, which is all used for conversion into steel, com- 
mon Welsh iron, which is hardly capable of being converted into steel, 
and Lowmoor iron from Yorkshire*. Mr. Buthray, a very intelligent 
steel-maker and iron-smelter in the neighbourhood of Glasgow, was 
kind enough to supply the specimens, so as to ensure their coming 
from the places stated. 

“ The first remarkable difference in these three specimens is their 
specific gravity. It was as follows: 


Best Dannemorairon . . . . 79125 
WGowmoor iron. . 2 .¢):.°. 773519 
IWrelshorrom 2), sels cae oF A059 


These differences are much greater than I expected to find: perhaps it 
will be more intelligible if I state them as follows: 


“ If the specific gravity of Dannemora iron be reckoned. 1000 
the Lowmoor iron willbe . 929 
the; Welsh iron: «2... « «939° 


5 Dr. Thomson was informed that this iron from Lowmoor was smelted with char-’ 
coal. 


, rape ae 


42 EIGHTH REPORT—1838. 


or Lowmoor iron is about 7 per cent. and Welsh iron 6 per cent. lighter 
than the best Dannemora iron. : 

“To analyze Dannemora iron I dissolved 100 grains of it in muriatic 
acid, evaporated the solution to dryness in a gentle heat, and redis- 
solved the residue in water slightly acidulated with muriatic acid. 
There remained undissolved a gray-coloured matter, which was tho- 
roughly washed, and dried at a temperature of 300°. It weighed 0°32. 
gr. or very nearly one-third of a grain. Being ignited in a platinum cru- 
cible, the weight was reduced to 0:06 gr. of a gray matter, which, 
examined before the blow-pipe, proved to be silica very slightly tinged 
with iron. The 0°26 gr. lost by ignition was probably carbon; for a 
temperature of 300° was doubtless sufficient to drive off all the water 
which might at first have been present. 

“ The muriatic acid solution was mixed with nitric acid and boiled for 
several hours in a flask, to peroxidize the iron. When cold, the excess of 
acid was neutralized as exactly as possible by carbonate of soda, taking 
care that no precipitate fell. It was then raised to the boiling point 
and thrown upon a filter. The whole peroxide of iron which it con- 
tains is retained upon the filter, and must be well washed with hot wa- 
ter. At first the water passes through the filter quite colourless ; but 
when most of the common salt is washed out the oxide of iron begins 
to pass also. ‘To prevent this we must wash it with water containing 
sal ammoniac Cissolved in it: this salt not only prevents the oxide of 
iron from passing, but the solution of it speedily replaces the common 
salt in the oxide, and thus enables us to wash it much more speedily 
and completely than we otherwise could do. The oxide being washed, 
dried, and ignited, weighed 142-23 grains, equivalent to 99°56 grains 
of iron. 

* The solution thus freed from iron was evaporated to dryness by a 
gentle heat: the residue redissolved completely in water, showing the 
absence of phosphate or arseniate of iron. The solution being mixed 
with carbonate of soda, a white powder fell, weighing after ignition 
0:07 grains. It was brownish red, and being fused with carbonate of 
soda it exhibited the well-known characters of red oxide of manganese. 
It was equivalent to 0:05 grain of manganese. According to this 
analysis, the constituents of Dannemora iron are 


IO Met, eye o> oO), on ERE: 
Cahors iss 1°. 4 ena eo 
Manganese... |. .« . 0°05 
SUUCOM ccc deca, O03 
99°90 

“Thus almost the only foreign matter in Dannemora iron is carbon, 
which cannot be injurious as far as steel-making is concerned ; for the 
manganese and silicon together amount only to 8 parts in the ten | 
thousand, or not so much as the >,/,5th part, which could not affect 

the quality to any great amount. 
«“ In the Lowmoor iron ] found no carbon; the only foreign bodies 


Spee 


> mm 
‘ast 
se 
\ 


TRANSACTIONS OF THE SECTIONS. 43. 


were manganese and silicon; the former to the extent of nearly 2 per 
cent., and the latter almost to that of ;,55th part: the analysis gaye 
Tronyieiys toh ert 298060 
Manganese . . . .  1°868 
Silicon . . . . . 0:090 
100.018 
“In the Welsh iron the quantity of manganese was small, but, owing 
to an accident, I did not separate it from the iron. The silicon was 
sensibly the same as in the Lowmoor iron. But in the Welsh iron I 
found another substance, phosphorus, to the amount of nearly a half 
per cent.; this substance is entirely wanting in the Dannemora and 
Lowmoor irons. The constituents of Welsh iron were 


Tron, with some manganese . 99°498 
Phespnormis- pj) 2). 0s fel se ALT 
PUNE tieat artic fic) fe)! se OBS 
100°000 
The presence of phosphorus is probably the reason why Welsh iron is 
too brittle to be converted into steel. 

“JT hardly think that these analyses enable us to account for the 
striking difference in the specific gravity of these three irons. I rather 
ascribe this difference to a mechanical cause; the Dannemora iron has 
probably been exposed to longer hammering or rolling than either of 
the British specimens. If this be so, it will in some measure explain 
its greater strength, for the strength of iron, ceteris paribus, is well 
known to increase with the degree of hammering to which it has been 
subjected.” 


On the Sugar in Urine of Diabetes. By Tuomas Tuomson, M.D. 
F-.RS., Professor of Chemistry, Glasgow. 


“ Though the existence of sugar in the urine of persons labouring 
under the disease called diabetes mellitus, has been known for more 
than a century and a half, having been discovered by Dr. Willis, who 
died in the year 1678, and though it has been frequeiitly extracted 
from such urine and exhibited in a state of purity, the author was not 
aware that experiments requisite to determine its nature had been 
made. After noticing the statement of Dr. Prout (Phil. Trans. 1827), 
that such sugar contained gr. 36 to 40 per cent. of carbon, and gr. 60 
to 64 per cent. water; Dr. Thomsen described the results of some ex- 
periments which he had recently undertaken to remove the uncertainty 
which appeared to involve the subject.” 

By evaporation, and subsequent digestion in alcohol, the sugar was 
obtained white, and by re-solution in boiling alcohol and slow cooling, 
acicular crystals were obtained. Specific gravity, when simply dried 
in air, 1378; heated to fusion (which takes place at 239°) the specific 
gravity becomes 1°4.23, while that of common sugar is 1°56, and that 


44 EIGHTH REPORT—1838. 


of sugar of grapes is stated by Prout at 1°5. Diabetic sugar dissolves 
without limit in boiling water, and at 62° in its own bulk of water. 

By analysis with oxide of copper, the constitution of this sugar was 
found to be 


Carbon...... 37:23 or 12 atoms = 9:00 or per cent. 38°09 

Hydrogen.... 7:07 WSs ake 1i625..ae 6°88 

Oxygen...... 55°70 ES. liess 13 e 55°03 
100°00 23°625 100°00 


Starch sugar, according to Dr. Prout, is composed of 


Carbon...... 12 atoms 9 
Hydrogen... 14%.) 1475 

OXyEEN. <j... 14 .. 140 

24°75 

differing from diabetic sugar by an additional atom of water. 


Pure crystallized sugar, according to the analysis of Liebig in 1834, 
is composed of 


Carbon...... 12 atoms 9 

Hydrogen,... 11 .. LS75 

Oxygen... -.. PN PLES 
21°375 


By uniting the diabetic sugar with oxide of lead, it was found to 
have combined with three atoms of oxide of lead, and to have lost three 
atoms of water, constituting a trisaccharate of lead, composed of 


Carbon.... 12 atoms = 
Hydrogen... 10 .. = 1°25 
Oxygen:,. «. 10 = 


Oxide of lead 3 .. = 42:00 


In this combination the diabetic sugar is therefore exactly isomeric 
with common sugar, in its combination with two atoms of oxide of lead, 
as determined by Berzelius. 

From. the yellowish-brown solution which had yielded the trisaccha- 
rate of lead the addition of alcohol caused a flocky precipitate to fall, 
which appeared, on analysis of a small quantity, to be disaecharate of 
lead, containing 


Supers fe A. 0°56 


Bede pilend re (0'Gk or nearly two atoms of lead to one of sugar; 


1-20 
and Dr. Thomson supposes from some trials he made that the sugar in 
this combination had lost two atoms of water, so as to be composed of 


a : 


TRANSACTIONS OF THE SECTIONS. 45 


Carbon, 12atoms= 9 
Hydrogen,11 .. = 1°375 
Oxygen 11 = 11° 


21375 


but the analysis requires repetition on a larger scale before any definite 
conclusion on this particular subject can be drawn. 

It appears from the facts stated in this paper that there are three 
species of sugar distinguished from each other by the quantity of wa- 
ter which they retain when heated to as high a temperature as they 
can bear without decomposition ; viz. common sugar, which may be 
deprived of one atom of water by combining with oxide of lead ; dia- 
betic sugar, which may in like manner be deprived of three atoms of 
water; and starch sugar, which by analogy may be presumed to be 
capable of losing four atoms: so that all the species would, under 
these conditions, become isomeric with anhydrous common sugar. 

If these views have any solidity, it would appear that sugar, like 
phosphoric acid, has in all cases the same constitution, and that the 
three states of it depend upon the quantity of water and probably of 
other bases with which it is disposed to combine. 

Common sugar combines with one atom of water, diabetic sugar 
with three, and starch sugar with four. There is doubtless a fourth 
variety of sugar, not yet discovered, capable of uniting with two atoms 
of water. 

All the three species are capable of undergoing fermentation and of 
being resolved into 4 atoms carbonic acid and two atoms alcohol. 


4, atoms carbonic acid.... Ct? Os 
2 atoms aleohol ........ Cs H!2 Ot 


ce Ae OR 


Starch sugar has an excess of 2 atoms of water and diabetes sugar 
of 1 atom ; while common sugar requires an atom of water to undergo 
the decomposition. 

Dr. Thomson had previously mentioned that 39°65 grains of diabetes 
sugar dried in vacuo over sulphuric acid, when exposed for 24 hours 
to the heat of a steam-bath, lost 3°35 grains of moisture, and were of 
course reduced to 36°3 grains. 

But 36:3 : 3°35 :: 23°625 : 2°18. 

It follows from this, that diabetes sugar dried over sulphuric acid is 
deprived of two atoms of water when exposed to the heat of a steam- 
bath or to 212°. The diabetes sugar, therefore, when in crystals, is 
composed of 


12 atoms carbon = 9 

15 atoms hydrogen = 1°875 

15 atoms oxygen = 15° 
25°875 


al or ae ie 


46 EIGHTH REPORT—1838. 


So that the atomic weight of the crystals of this sugar is 25°875, and 
it can be deprived of 5 atoms of water by combining it with oxide of 
lead. 

Dr. Thomson then noticed a crystallized sugar obtained from diabetic 
urine by Mr. Macgregor of Glasgow, by Ambrosiané and Maitland 
from the serum of blood in diabetes, and by himself in urine in a case 
of diabetes, 1827. This sugar was in 4-sided prisms of 110° and 70°, 
white, translucent, sweetish, soluble in alcohol. This is believed by 
Dr. Thomson to be a fourth kind of sugar, but having been interrupted 
in his experiments upon it he recommends the subject to the attention 
of chemists. 


On Galactin. By Tuomas Tuomson, M.D., F.R.S., Professor of 
Chemistry, Glasgow. 


This is a substance which constitutes the principal ingredient in the 
sap of the Cow-tree, or Galactodendron utile of South America, which 
is used as a substitute for cream. The sap, on standing, throws up a 
white matter, soluble in boiling alcohol, but deposited as that liquid 
cools. When well washed and dried, in vacuo, over sulphuric acid, it 
constitutes galactin. It is yellow, translucent, brittle, has a resinous 
aspect, and is tasteless. It is insoluble in water, but becomes white 
and soft by imbibing that liquid. It is soluble in alcohol and ether. 
This white compound becomes soft and ductile at 60°; at 117° it is 
still solid, but at 137° it is liquid. Abundance of aqueous vapour is 
driven off, but the galactin does not become translucent and yellow till 
kept some time at 170°. The specific gravity of pure galactin is 0°969. 
It dissolves readily in oil of turpentine and olive oil. It does not com- 
bine with potash, nor form a soap. Its constituents are— 


6 atoms carbon = 4°5, or per cent. 72 
Giessen: hydrogen = O°75 ....sccee seen 12 
MV Gacorce Oxygen = DP ean ecstene 16 

6°25 100 


being isomeric with Brazil wax, which does not, according to Mr. 
Brande, form a soap with potash. 


Notice respecting the native Diarseniate of Lead. By Tuomas Tuom- 
son, M.D., F.R.S., Professor of Chemistry, Glasgow. 


During the last meeting of the British Association at Liverpool, a 
mineral dealer from Cumberland exposed a collection of North of 
England minerals for sale. Among others there was one labeled vana- 
diate of lead, from Caldbeck fell. On examining it, Dr. Thomson 
thought that it differed too much, both in its colour and lustre, from 
the true vanadiate of lead, of which he had been in possession for 
some years, to be that mineral; and, upon comparing it with the vana- 
diate in his cabinet, this suspicion was confirmed. 


pte an’ Sls 
eo. 
nr 
—_—” ms 


TRANSACTIONS OF THE SECTIONS. 47 


The Caldbeck fell mineral was in botryoidal concretions, upon 
quartz. When examined by the microscope many of the nodules had 
the aspect of cylinders. 

Colour honey yellow, similar to that of the Cornish arseniate of lead, 
first described and analyzed by Mr. Gregor, but lighter, and much less 
translucent. 

The lustre is resinous, and it has much greater brilliancy than speci- 
mens of vanadiate of lead. 

The hardness is not easily determined, from the shape of the no- 
dules. Calcareous spar was not seratched by rubbing them against it 
while selenite was scratched by them with great facility. The specific 
gravity by two different trials was.7-272. This specific gravity is 
decisive that the mineral is not vanadiate of lead, for the specific gra- 
vity of native crystals of vanadiate is only 6°663. The specific gravity 
of Cornish arseniate of lead is still lower, being 6°41. 

When exposed to a red heat on platinum foil it undergoes no altera- 
tion, except becoming a shade lighter in colour. Before the blow-pipe 
on platinum it melts into a transparent globule, which assumes nearly 
its original appearance on cooling, and does not crystallize like phos- 
phate of lead. On charcoal it gives out abundance of arsenical fumes, 
when acted on by the blow-pipe, and a globule of metallic lead is ob- 
tained. 

It was analyzed twice in Dr. Thomson’s laboratory, with every at- 
tention to accuracy, by Mr. Stenhouse. During the first analysis he 
suspected the presence of a minute quantity of phosphoric acid; but 
he did not succeed in separating it from the arsenic, and of course the 
actual existence of this acid in the mineral is still problematical. The 
quantity is certainly very minute, and cannot amount to so much as 
half per cent., otherwise it would have been separable from the arsenic 
acid. 

The two analyses were very similar: the following are the consti- 
tuents as determined by the second analysis, which Mr. Stenhouse 
considers as most to be depended on : 

Chlorine. : 3 ~ 246 
Lead f : : prema fe) 
Arsenic acid : : ees 20: 
Protoxide of lead : - 70°14 
Peroxide of iron : =f ZO 
Volatile matter . : - 1:00 
100°1 

The moisture and peroxide of iron are obviously accidental impuri- 
ties. The chloride of lead in 100 grains of the mineral amounts to 
about half an atom, the arsenic acid to 24 atoms, and the oxide of lead 
to 5 atoms. If we abstract the chloride of lead, which exists in nearly 
the same proportion in phosphate of lead, vanadiate of lead, and arse- 
niate of lead, as in this mineral, the constituents are 1 atom arsenic acid, 
and 2 atoms protoxide of lead. It is therefore a diarseniate of lead, 
constituting a new species of lead ore, which has been met with 


48 EIGHTH REPORT—1838. 


the first time in Cumberland at Caldbeck fell. The author's spe- 
cimen of this mineral exhibits a deposit of yellow.phosphate of lead 
upon another side of the mass of quartz, upon which the diarseniate 
has been deposited. 


On Emulsin. By Dr. T. Tuomson and T. Ricuarpson. 


Some years ago Robiquet and Boutron Charlard showed that volatile 
oils of bitter almonds and prussic acid, which are obtained by the di- 
stillation of bitter almonds, do not exist naturally in almonds but re- 
sult from the process. They further ascertained that when milk of 
bitter almonds, formed by triturating almonds with water in a mortar, 
is treated with strong boiling alcohol, white crystals are deposited, on 
cooling, which separate in larger quantity by concentration. To this 
substance they gave the name of Amygdalin. Liebig and Wéohler have 
determined this body to be an amide of amygdalic acid, represented 
by the following formula: 


Ng Cyo Hs Oo + Hy Op 


Subsequently, the investigation was continued by Wohler and Liebig, 
who observed that when a solution of amygdalin is brought in contact 
with a milk of sweet almonds, a most remarkable and peculiar action 
takes place; prussic acid and oil of bitter almonds are formed, as in 
the instance already mentioned, When mi!k of bitter almonds is distilled 
without the artificial addition of amygdalin, besides prussic acid and 
oil of bitter almonds, there is also formed sugar, which may be de- 
composed by fermentation. The solution after the termination of the 
fermenting process affords a strong acid reaction which is not produced 
by acetic acid or any other volatile acid. When alcohol is added and 
the solution concentrated, thick white flocks are precipitated which 
obviously contain no emulsin, because when dissolved in water they 
have no action upon amygdalin. From these properties the flocks 
would appear to be gum. 

The phenomena exhibited in the reaction described, which have 
been termed Catalytic by Berzelius, resemble in a great measure those 
which take place in fermentation; and their investigation promises to 
throw great light upon some of the most important processes of the 
vegetable and animal ceconomy. With the view of assisting in the 
elucidation of the subject, the authors have commenced with the ex- 
aiination of the essential ingredient of the milk of sweet almonds which 
has been termed emulsin. 

The process by which this substance was obtained was as follows, 
Sweet almonds were triturated in a mortar and small portions of water 
were gradually added until a milky fluid was obtained. This fluid was 
mixed with four times its volume of ether and frequently agitated so 
as to effect an intimate mixture. A clear fluid gradually separated at. 
the bottom of the stoppered bottle in which the experiment was made, 
which in the course of three weeks was drawn off by means of.a syphon. 
This fluid was passed through a filter, and to one-half of the clear so- 


TRANSACTIONS OF THE SECTIONS. 49 


lution a large quantity of alcohol was added; a copious precipitation 
of white flocks ensued; these were emudsin. From the other half the 
emulsin was separated by bringing the solution to the boiling point, 
when it precipitated in flocky coagula. The emulsin precipitated by 
alcohol was carefully washed with alcohol, and then dried over sulphu- 
ric acid in the vacuum of an air-pump, to avoid the effects of heat. In 
this state it possessed the following characters: it is a white powder, 
destitute of taste and smell, soluble in water, insoluble in aleohol and 
ether. When submitted to analysis in the usual way, the following 
results were obtained : 


I. +3485 ¢rns. gave ‘6180grns. CO, and -244.5grns. He O. 
Il. -3625grns. gave *6365 grns. COg and *2505 grns. He O. 


The relation of the carbon and azote, as determined by experiment, 
was 6 CO,:1N or 3C:1N. From these data, which the authors 
would desire to state only with diffidence till better confirmed, the 
following composition may be deduced : 


I. Il. 
C. 49°025 48°555 
N. 18-910 18-742 
H. 7°788 7077 
O. 24277 25°026 
100-000 100°000 


The fact of the existence of the substance operated on in the almonds 
appears to be established by its acting on amygdalin in the same man- 
ner as the milk of almonds in the case alluded to in the commencement 
of the paper. After numerous trials with various re-agents, its most 
distinguished character was elicited by the phenomena exhibited when 
boiled with barytes. During the whole of the boiling, which was con- 
tinued for above six hours, ammonia was slowly and continuously dis- 
engaged. Through the solution a current of carbonic acid was passed 
and the whole filtered ; the clear solution was evaporated to dryness, 
and the residual salt, which contained a large quantity of barytes, pos- 
sessed a strongly bitter taste, leading to the conclusion that emulsin 
is an amide, and that the salt formed by the action of barytes is a com- 
pound of barytes with an acid which it is proposed to term emulsie 
acid. From this fact the authors are inclined to infer that fibrin, ge- 
latin, casein, &c., are all amides. 


Examination of Sphene. By Tuomas Richarpson. 


The author having been supplied with two specimens of sphene by 
Mr. Hutton, of Newcastle, submitted them to analysis. One of these, 
from Arendahl, in Norway, possessed a specific gravity of 3-425 :—co- 
lour, light brownish yellow ;—translucent ;—brittle ;—fracture uneven; 
—lustre vitreous, inclining to resinous. The mineral was fused with 
carbonate of soda, and the fused mass digested in the cold with dilute 

VOL. VII, 1838, E 


50 EIGHTH REPORT—1838. 


muriatic acid.. Caustic ammonia was added, and the precipitate 
separated by filtration. The precipitate was washed with cold di- 
stilled water, and in this state was exposed to the air for about six weeks 
without the application of heat, when it appeared quite dry. The 
solution and washings from the precipitate were carefully evaporated 
to dryness, but on digesting the same with water everything redissolved, 
showing that all the silica had been precipitated by the ammonia. 
The solution, after being gently heated, was mixed with oxalate of am- - 
monia, and the precipitated salt of lime thrown on a filter. The dry 
precipitate obtained by ammonia was digested in the cold with con- 
centrated muriatic acid, and the insoluble portion, after the ordinary 
washing and ignition, weighed. The titanic acid was precipitated from 
the filtered solution after being gently warmed by caustic ammonia, of 
which reagent an excess was carefully avoided. The specific gravity 
of the second specimen was 3°5128 ; hardness, 6°75;—lustre, resinous; 
—colour, cinnamon - brown ;—cross fracture, granular and uneven ;— 
opaque, but translucent in thin plates. Before the blowpipe alone on 
charcoal, it became white, but did not fuse. With carbonate of soda 
in the oxidizing flame it fused into an orange bead. Its locality is not 
known. The following is the composition of the two specimens :— 

UNC oie ti hal > 31°05 29°35 

Titanic Acid .... 43°90 42°60 

TMG Jaleate + «o'er ee 24°90 


and the formula, 


3 (Ca O, 2 TiO,) + 2 (CaO, 2 Si O;). 


On a New Process for the Extraction of Silver from Lead. 
By H. L. Parrinson. 


The object of this communication was to lay before the Association 
an account of a discovery made by the author some time ago, the ap- 
plication of which to practice constitutes a new process in the arts, and 
forms an important improvement in the extraction of silver from lead. 

Adopting the estimate of Mr. J. Taylor, in 1828*, that the quantity 
of lead raised annually in England and Wales amounts to 45,500 tons, 
the author states that it all contains silver, in variable proportions, but 
with so much of constancy in the proportion of silver in the lead ore of 
each vein, that it is easy to arrive at a tolerably accurate knowledge of 
the quantity of silver contained in the lead of each district. 

Of 22,000 tons of lead yielded in the district of Alston Moor, it is 
believed that 16,000 tons contain silver at the rate of from 6 to 12 oz. 
per ton, and 6000 from 31 to 6 oz. per ton—the average being about 5. 


* See Records of Mining for that year; also Reports of the British Association, 
vol. v., for an estimate, by Mr, J. Taylor, of the quantity of lead raised in Great Bri- 
tain in 1835, 


TRANSACTIONS OF THE SECTIONS. 51 


4700 tons from Swaledale, and Wharfdale, Pateley Bridge, &c. yield 
on an average only 2 oz. per ton. The lead of Derbyshire and Shrop- 
shire, 4800 tons, from 1 oz. to 14 0z. only. The lead of Cornwall and 
Devon, 2000 tons, is rich in silver, so as to yield on an average 20 to 
30 oz. per ton; half of that from Flintshire and Denbighshire, contains 
from 44 to 64 oz., and the other half 9 or 10 oz. 

The ordinary process of cupellation or refining*, consists in the 
oxidation of the lead, kept at a red heat, and traversed by a current of 
air; the silver remains nearly pure; the oxide of lead is either re- 
duced, or sold as litharge. The cost of this process and the waste of 
lead are so considerable, that with lead at the price of 20/. the ton 
from 6 to 8 oz. of silver are required to barely cover the whole charge 
against the operation. About 18,000 tons of the whole quantity raised 
in England and Wales are supposed to undergo the refining process ; 
and the waste of lead upon the whole quantity would amount to 1000 
tons. Where the lead before refining was impure, with admixture of 
other metals, its quality is improved by the process, sometimes to the 
value of 10s. a ton; but this is only the case in small quantities. 

The desirableness of some more economical mode of extracting silver 
from lead has been long obvious to those conversant with that branch 
of our national industry; and Mr. Pattinson had for some years been 
engaged in occasional experiments on the subject. Among these, he 
describes the attempts which he vainly made to separate the lead from 
the silver by distillation and long-continued fusion. 

Various other experiments were tried by the author, both in the dry 
way and by the application of liquid menstrua, all of which were un- 
successful; but during their prosecution in the month of January 1829, 
he required lead in a state of powder, and to obtain it, adopted the 
mode of stirring a portion of melted lead in a crucible, until it cooled 
below its point of fusion, by which the metal is obtained in a state of 
minute subdivision. In doing this he was struck with the circumstance, 
that as the lead cooled down to nearly its fusing point, little particles 
of solid lead made their appearance, like small crystals, among the li- 
quid lead, gradually increasing in quantity as the temperature fell. 
After observing this phenomenon once or twice, he began to conceive 
that possibly some difference might be found in the proportions of sil- 
ver held by the part that crystallized, and the part that remained liquid. 
Accordingly, he divided a small quantity of lead into two portions, 
by melting it in a crucible, and allowing it to cool very slowly with con- 
stant stirring until a considerable quantity crystallized, as already men- 
_ tioned ; from which the remainder, while still fluid, was poured off: an 
equal weight of each was then submitted to cupellation, when the button 
of silver from the liquid lead was found to be very much larger than 
that from the crystallized lead; proving that argentiferous fluid lead 
suffers a portion of silver to escape from it, under certain circumstances, 
in the act of becoming solid. 


__* See Mr. Sadler’s Essay in Nicholson’s Journal, vol. xv., and Mr, Pattinson’s paper 
in Neweastle Transactions, yol, xi. pt. I, 


EQ 


Peres SO 


52 EIGHTH REPORT—1838. 


The lead used in the original experiment was what is considered rich 
in silver; it contained 40 oz. 15 dwts. 8 grs. per ton, and was divided 
into a crystallized portion, found to contain 25 oz. 4. dwts. 21 grs., and a 
fluid portion, holding 79 oz. 11 dwts. 12 grs. per ton; the latter being ne- 
cessarily much smaller than the former in quantity. The experiment 
was repeated a great number of times upon lead of every variety as to 
proportion of silver, with the same general result ; but being always per- 
formed in a crucible upon small quantities of lead, which of necessity © 
cooled quickly, the crystallized portion was never entirely deprived of 
its silver, nor indeed reduced below two or three ounces per ton. 

It was not until the spring of the year 1833 that the author was con- 
veniently circumstanced to proceed in applying to practice the principle 
he had developed; but at that time his attention was again directed to 
the subject, and he began by providing large pots of cast iron, in each 
of which he could melt together and crystallize several tons of lead. All 
the phenomena of crystallization in the large way were speedily observed, 
which, with the mode of conducting the operation adopted then and since 
continued without alteration, may be thus briefly described. Four or 
five tons of lead being melted in one of the pots, the metal was carefully 
freed, by skimming, from all dirt or oxide, and its surface made quite 
clean ;-it was then suffered to cool very slowly, care being taken to 
break off and mix with the fluid mass, from time to time, any portion 
that might congeal on the sides of the pot: when the temperature had 
fallen sufficiently, small solid particles or crystals began to form, princi- 
pally upon the surface of the melted mass. These, if suffered to remain, 
would have cohered together and formed a solid crust; but being con~ 
tinually struck, and the whole body of metal kept in motion by constant 
stirring, they sunk down to the bottom of the pan, and soon appeared 
in considerable quantity. By means of a perforated iron ladle, the ery- 
stals were taken out of the pan from time to time as they formed, and 
placed in another pot, the liquid lead being drained out of them as much 
as possible, and suffered to flow back into the original pot. In this way 
the operation was conducted until two-thirds or three-fourths of the ori- 
ginal lead was crystallized and withdrawn from the pot. The author 
now found, as before, that the crystals always contained much less silver 
than the lead from which they were formed ; but still he did not succeed _ 
by one or even by two crystallizations, when operating with lead con- | 
taining eight ounces of silver per ton, in making them sufficiently poor: 
for instance, a pot filled with 8 ounce lead would yield at first crystals 
holding from 1 to 2 ounces of silver; in a little time, as the lead in 
the pot became richer by receiving silver from the previously formed 
erystals, it yielded crystals of 2 to 3 ounces; and the crystals became 
progressively richer, until, in the end, the original lead was divided into 
three parts of crystalized lead holding about 4 ounces, and one part li- 
quid lead holding about 20 ounces per ton. Upon the lead of 4 ounces, 
as well as upon the lead of 20 ouuces, the operation might evidently be 
repeated without limit, until the crystals became nearly free from silver 
on the one hand, and the liquid lead exceedingly rich on the other; but 
this seemed to involve so much labour and delay, that the author was 


TRANSACTIONS OF THE SECTIONS. 53 


most desirous of finding a mode by which the object could be accom- 
plished at once. Conceiving that the crystals would be rendered poorer 
if more thoroughly drained from the liquid lead, he adopted the plan of 
exposing them, after removal from the pot to a cautiously regulated 
heat in the chamber of a reverberatory furnace, so as to melt out from 
among them a further portion of liquid lead; and in this way he suc- 
ceeded in obtaining at one operation from original lead holding 12 
ounces of silver per ton, four parts of poor lead containing not more than 
2 of an ounce per ton, and one part of rich lead containing 50 ounces 
per ton, or thereabouts. This was effected at a moderate expense, and 
with a very inconsiderable loss of lead; and the new process thus ar- 
rived at, which he called the process of separation, was immediately 
adopted and carried on in this way for some time at different lead-works 
in the kingdom. 

The exposure of the crystals a second time to heat, required, how- 
ever, a peculiar and rather expensive apparatus, and was found somewhat 
difficult to get managed properly, for the workmen could not always keep 
the furnace in which it was performed at the exact temperature neces- 
sary for the operation ; and it often happened that, by the application 
of too much heat, the crystals were melted entirely without being drained 
of their richer Jead ; besides, the lead exposed to heat in its crystallized 
state was oxidized rapidly, and the subsequent reduction of the oxide 
occasioned some loss of metal. These objections to the draining pro- 
cess induced the author to recommend in preference the simple plan of 
repeated crystallization, which has been everywhere adopted, and now 
constitutes the process of separation ; experience and practice have gra- 
dually rendered it easy and perfect, and it has become an established 
operation among the arts of this country. 

The apparatus required for the separating process is exceedingly sim- 
ple, and consists merely of a number of nearly hemispherical iron pots, 
each capable of holding about five tons of lead, the size for which is about 
4 ft. diameter and 2 ft. 3 in. deep ; one or two smaller pots, 18 in. diameter 
by 2 ft. deep, are required for the purpose of holding melted lead, in 
which the perforated iron ladles are to be occasionally dipped to keep 
them hot; and another pot, about 2 ft. 10 in. diameter by 1 ft. 10 in. 
deep, for melting the ultimate poor lead to be cast into pieces. These, 
with a few perforated iron ladles 15 in. diameter, and 5 in. deep, and 
one or two whole ladles of lesser size for casting the melted lead 
into pigs, are the principal articles required. The large pots are to be 
placed side by side in a line, each with a separate fire-place, (upon 
which there must be an ash-pit door as well as a fire door, ) and also with 
a separate flue and damper, so that the draught under each pot can be 
entirely stopped by closing the flue with its damper, and the heat of the 
fire-place in some measure retained by shutting the ash-pit door. Above 
the centre of this line of pots, at the height of six or eight feet, it is con- 
venient to have a small iron railway, with a frame or carriage on four 
wheels to move backwards and forwards the whole length of the range 
of pots, from which is to depend a chain, terminated by a hook at the 
bottom, and reaching to nearly the top of the pots. This is for the 


54 EIGHTH REPORT—1838. 


purpose of more easily conveying the ladles filled with crystals from 
pot to pot. : 

All this being provided, one of the large pots is filled with lead, con- 
taining silver, say 10 oz. per ton, and after it is melted and skimmed, 
the fire is withdrawn, the damper put down, and the ash-pit door 
closed, when it cools and crystallizes as already described. Crystals, 
as they are formed, are laded out into the second pot until about three- 
quarters of the whole have been removed, which will contain about 5 © 
ounces of silver per ton: upon this the operation is repeated, giving lead 
2 ounces; and by a third crystallization, there is obtained from this, 
poor lead, holding not more than 10 to 15 dwts. of silver per ton, 
which is cast into pieces for sale as separated lead. The rich lead, on 
the other hand, is collected and repeatedly crystallized, until it is made 
to contain 200 or 300 ounces per ton, after which the silver is extracted 
by cupellation. In working, the different pots at each stage are filled 
up always with lead of the same content of silver before beginning to 
crystallize, and a greater or less amount of crystals taken out, as the 
operator may think fit, in which respect the practice differs almost at 
every establishment ; but the process is so very simple and the mode 
of proceeding so obvious, that it is unnecessary to give a more minute 
detail. : 

By operating in the way described, it is evident that but a very small 
portion of lead is made to undergo the process of cupellation, not more 
than one twentieth part, when 10 ounces of lead is enriched to 200 
ounces by repeated crystallization ; and as the loss by separation has 
not been found to exceed a 250th part of the whole lead, the loss by 
the joint processes becomes ;y of og + g45, or about one part in 
120. The expense of separation is something less than that of cupel- 
lation, so that by the reduction of expense and the reduction of loss of 
lead, the extraction of silver is so far economized that 3 ounces per 
ton will now fully cover the whole charge. 

By this reduction of the cost of extracting the silver, a// the lead of 
Alston Moor (22,000 tons), Devon, Cornwall, and West Cumberland 
(2000), and the lead of North Wales (12,000), making a total of 
36,000 tons per annum, can now be made to yield up its silver with ad- 
vantage, so that on the very low average of 6 ounces per ton, at least 
54,000 ounces of silver per annum are gained by the arts. There may 
also be safely estimated a reduction of the loss of lead on the 18,000 
tons generally refined by cupellation of at least 300 tons. The lead 
obtained by separation is much improved in quality, being more soft 
and ductile than ordinary lead. 

It only remains to consider, how it happens that lead in the act of 
consolidation gives up a portion of its silver to the surrounding and 
still fluid lead ; and the most simple view of the matter is, undoubtedly, 
that it is an instance of true crystallization, in which the homogeneous 
particles of lead are drawn together by virtue of their molecular at- 
traction, to the exclusion of the foreign body, silver. On examining 
the crystals, it is true, no trace of regular form can be perceived ; but 
this could searcely be expected, from their being so much agitated and 


- 


TRANSACTIONS OF THE SECTIONS. 55 


broken at the instant of their production: if, however, a pot in the act 
of crystallizing is suffered to remain at rest a few moments until a 
crust forms on its surface, on carefully withdrawing a portion of this 
crust, it is found on its under side to exhibit a distinctly crystalline ap- 
pearance, proving that the solid particles, which are merely this crust 
broken to pieces, are the result of a rapid crystallization. 

This reasoning the author endeavoured to confirm by illustrations 
drawn from other chemical processes, and mentioned experiment to 
ascertain the degree in which, by a cautiously regulated heat, silver 
may be separated from lead by the process of eliquation. Pieces of 
lead were most cautiously heated till a few drops of fused metal oozed 
out from their pores; this was found to be slightly richer in silver than 
the original mass. In these experiments, as in the draining of the cry- 
stals, the separation is effected by the difference of fusibility between 
pure lead and lead containing silver, aided, no doubt, by the tendency 
of pure lead, in that state of semi-fluidity, to assume a crystalline form. 


Observations on some of the Products obtained by the Action of Nitric 
Acid on Alcohol. By Gourvine Birv, M.D., F.L.S., GS, c., 
Lecturer on Natural Philosophy at Guy's Hospital, London, &c. 


In this paper the author alluded more particularly to the nature of 
the substances produced simultaneously with hyponitrous ether during 
the preparation of the spiritus etheris nitrici of the London Pharma- 
copeia, which products have been usually stated to be malic, oxalic, 
acetic, and carbonic acids, together with a substance mentioned by 
Thenard as “ trés facile A charbonner,” in addition to the hyponitrous 
ether (4C,5H,O+N,30). Taking advantage of the residue left 
after preparing a large quantity of sp. eth. nit. in the pharmaceutical 
laboratory of Guy’s Hospital, Dr. Bird instituted a series of experi- 
ments enumerated in his paper, from which he was induced to believe 
that oxalic acid was by no means a necessary product, and that it is 
not generated until aldehyd begins to appear in the distilled fluid. As 
the paper is published entire in the Philosophical Magazine for this 
year, it is unnecessary to do more than give the result of Dr. Bird’s 
investigations : 

1. That in the preparation of sp. etheris nitrici, as long as the latter, 
with alcohol only, distils over, no oxalic acid is produced ; an acid ap- 
parently identical with the oxalhydric alone appearing in the retort. 

2. That on continuing the distillation beyond this point, the free 
nitric acid in the retort acting on the oxalhydric acid, generates oxalic 
acid. ° 

3. That during the action of nitric acid on alcohol in the cold, as in 
Dr. Black’s process for the preparation of hyponitrous ether, acetic 
acid is produced, instead of, or in addition to, oxalhydric acid. 

4, That aldehyd is, as has been long known, produced by the action 
of nitric acid on alcohol, but that it is not formed in any quantity, or at 


cae SOT 


56 EIGHTH REPORT—1838. 


least does not appear in the distilled fluid until the formation of hypo- 
nitrous ether has nearly or altogether ceased. a 

5. That the production of aldehyd and oxalic acids are nearly si- 
multaneous; and that both these appear to result from the secondary 
action of nitric acid upon products formed in the earlier stages of the 
operation. 

6. That the erystals long known as “es cristaux de Hierne” formed _ 
when the distillation is protracted until red fumes appear, are oxalic 
acid, notwithstanding their remarkable micaceous form ; and that the 
‘‘ substance trés facile 4 charbonner” of Thenard is probably aldehyd, 
which, from its behaviour with alkalies, might apparently merit that 
character. 


Notice respecting the Artificial Formation of a Basie Chloride of Cop- 
per by Voltaic Influence. By Gouvine Binv, M.D., Se. 


Becquerel has proved that a homogeneous metallic surface exposed 
to the action of a given fluid will assume a state of electric tension, 
provided that the fluid in which it is immersed is of different degrees 
of concentration in two different layers, so that the plate may become 
unequally acted upon at two different points. The crystallization of 
protoxide of copper by the immersion of a plate of that metal in a so- 
lution of its nitrate, some of the black oxide being placed in the lower 
part of the vessel, affords a familiar example of this circumstance. But 
if the fluid remains homogeneous, guoad its degree of concentration, 
no action, so far as electricity is concerned, ensues, unless one portion 
of the metallic surface immersed is in a condition which enables it to be 
more readily acted on than the other. This may be effected by partial 
and superficial oxidation, by roughening or burnishing part of the me- 
tallic surface, or by the induction of that peculiar passive state which 
Schénbein has shown to exist in some metals under certain circum- 
stances. 

If a plate of metallic copper is made the negative electrode of a single 
pair, acting on a solution of copper, crystallization of the latter metal, 
often in delicate, rosette-like patches, if the current is weak, ensues. 
This deposition generally takes place at the lower part of the metallic 
plate, leaving the upper one smooth and free from crystals. A plate 
thus prepared is in a condition to assume two different electric states 
on immersion in a homogeneous fluid, in consequence of the delicate 
crystals of metallic copper undergoing oxidation more readily than the 
smooth part of the plate. Such a piece of metal was immersed in a so- 
lution of common salt during three months in a dark closet; on ex- 
amining the plate at the end of that time, the smooth portion, on which 
no metallic crystals had been deposited, was found tarnished and covered 
with blackish patches, without any perceptible roughening of the sur- 
face. The lower portion of the same plate on which the copper had 
crystallized had undergone a very interesting change, the metallic 
crystals having become replaced by an infinite number of hemispheri- 


TRANSACTIONS OF THE SECTIONS. 57 


cal patches from a mere point to the size of a large pin’s head, of a rich 
green colour, of a somewhat velvety or satiny lustre. On breaking 
some of the crystals. they were found to be radiated like zoolite, without 
any metallic nucleus, and firmly adhering to the copper on which they 
were deposited. The crystals were insoluble in water, did not effervesce 
with sulphuric or nitric acids, in which they were with difficulty solu- 
ble, the solution being at first brownish, and readily becoming green by 
exposure to the air: their solution, in dilute nitric acid, precipitated 
nitrate of silver. These hemispheric-radiated crystals are therefore re- 
garded by Dr. Bird as a basic chloride, probably resembling the native 
tribasic chloride. This, however, he has not yet had an opportunity of 
proving by direct analysis. 

The theory of the formation of these crystals appears to be very 
simple. On immersing the copper plate into the brine, its electricity 
became disturbed, and two states of electric tension were assumed, the 
smooth and polished part becoming the negative, and the rough and 
crystalline portion the positive electrode of a simple voltaic circle. The 
chloride of sodium becoming decomposed, the chlorine uniting with 
the crystalline surface of the positive electrode, the soda being at first 
set free, although probably almost immediately after re-acting on the 
newly-formed copper salt, and thus reducing it to the state of basic 
chloride, the crystalline deposition resulted from the slowness of the 
action, as in Becquerel’s experiments. 


Notice respecting the Deposition of Metallic Copper from its Solutions by 
slow Voltaic Action at a point equidistant from the Metallic Surfaces. 
By Go.vine Birp, M.D., §e. Se. 


At the last meeting of the Association Dr. Bird presented some re- 
marks on the possibility of reducing metallic bases on surfaces not in 
contact with the electrode*. During the past year he has varied his 
experiments, chiefly with a view to the prevention of any source of 
fallacy connected with accidental metallic contact; and, although 
he has repeatedly succeeded in reducing metals on, or in the cen- 
tre of masses of earthy substances, as plaster of Paris or clay, he 
has never yet obtained metallic deposits in a fluid intermediate be- 
tween electrodes when these substances were absent. An interesting 
modification of the apparatus, described at Liverpool, has been con- 
trived by Mr. Sandall, chemical assistant at St. Thomas’s hospital, 
whilst engaged in constructing a voltaic battery on Prof. Daniell’s ar- 
rangement, but in which the membranes should be replaced by cylin- 
ders of sulphate of lime. This gentleman carried on his experiments 
during this summer, and Dr. Golding Bird requested him to break up 
the masses of plaster that had been used in his arrangement, for the 
purpose of ascertaining whether any deposition of metallic copper had 
taken place at any part not in connexion with the metallic surfaces, as 


* See vol. vi., p. 45. 


ad {oe aa 


58 EIGHTH REPORT—1838. 


he considered these results would go far to support or refute the opi- 
nions he had hazarded on this subject. e 

The results of these experiments were uniform ; they differed from 
Dr. Bird’s in one remarkable circumstance, viz. that the copper, instead 
of being deposited in a crystalline form, was in nodular or tubercular 
masses (a specimen was exhibited to the Section). When the plaster of 
Paris diaphragm, which of course was vertical, was carefully made, and. 
one side of ajar thus divided was filled with water, and the other with 
a solution of sulphate of copper, no intermixture of fluids was evident 
even at the end of a month. On placing in the solution of sulphate 
of copper, at a certain distance from the vertical partition, a mass of 
copper pyrites, connected by a copper ribbon with a piece of zine im- 
mersed in the water in the other cell, voltaic action slowly commenced. 
At the end of a few days the water in the zinc cell became acid, bub- 
bles of hydrogen gradually appeared, and were slowly evolved, whilst 
the copper pyrites slowly assumed the iridescent appearance of peacock- 
ore described by Mr. Fox: in a month the apparatus was dismounted ; 
no trace of sulphate of copper was found in the water cell, and neither 
the zine nor the mass of pyrites had touched the plaster diaphragm. 
On removing the latter, a copious deposition of firmly adherent me- 
tallic copper, in a nodular or almost stalagmitic form, was found on that 
surface which had been exposed to the metallic solution; and, on 
breaking the mass of plaster transversely, numerous delicate veins of 
copper appeared permeating it in every direction. This experiment is 
considered by Dr. Bird to be less liable to sources of fallacy, and 
much less exceptionable than those described by him last year; for, 
not only is all metallic contact with the plaster diaphragm carefully 
avoided, but the very form of the reduced copper would afford an ar- 
gument against. its being furnished by portions shooting off from the 
negative electrode, on the beautifully iridescent surface of which, 
moreover, no trace of reduced copper had appeared. 


Arrangement of the Apparatus. 


A is a conical earthen vessel, in which the 
plaster diaphragm B is carefully fitted. 

C. The cell filled with water, and contain- 
ing a piece of zinc metallically connected with 
a mass of native copper pyrites, placed in the 
cell D, which is filled with a solution of sul- 
phate of copper. On the surface of B, where 
the irregularities E are sketched, is the cop- 
per deposited in a nodular form, and con- 
nected apparently with delicate metallic veins 
traversing B in every direction. 


TRANSACTIONS OF THE SECTIONS. 59 


On a new Compound of Sulphate of Lime with Water. 
By Prof. Jounston, F.R.S. 


This compound is represented by 2Ca S + H, and occurs in masses 

_ of a minute radiated structure, in minute cylindrical crystals, and in 
large six-sided prisms. It is formed as a sediment in the boiler of a 
steam engine at the Team Colliery, near Newcastle. The boiler is 
worked under an average pressure of about two atmospheres. (See the 


Lond. and Ed. Phil. Mag. for Nov. 1838.) 


On a new Compound of Bicyanide with Binoxide of Mercury. 
By Prof. Jounston, F.RS. 


When dilute hydrocyanic acid is digested on red oxide of mercury 
in excess, a white nearly insoluble compound is formed, which may be 
separated from any soluble bicyanide which may be present in the su- 
pernatant liquid by collecting it on the filter. Boiling water dissolves 
the new compound, and leaves the excess of oxide of mercury. On 
cooling, the salt is, in a great measure, deposited on the sides and bot- 
tom of the vessel in minute, pure, white, transparent, prismatic needles. 
This salt is anhydrous, its solution has an alkaline reaction, and it con- 
sists of equal atoms of the two mercurial compounds, or it is (HyCy, 
+ HyO,). When heated in a tube, it decomposes with a slight deto- 
nation, giving off carbonic acid, nitrogen, cyanogen, and metallic mer- 
cury, leaving a black residue ( para-cyanogen). Neutralized by nitric 
acid, it gives a beautiful salt in long, delicate, quadrangular prisms, 
which are represented by HyCy, + (HyO, + 3 NO,), and are very 
soluble in water. It gives also with acetic acid, a crystalline compound, 
in which the quantity of acid appears to exist in a still smaller propor- 
tion. With acid nitrate of silver, it gives Wohler’s salt (HgCy, + 


AgN = 4H), nitrate of mercury remaining in solution. With neutral 
nitrate of silver and various other salts, it gives crystalline compounds. 


On some supposed Exceptions to the Law of Isomorphism. 
By Prof. Jounston, F.RS. 


In this paper the author endeavoured to show, that if the chemical 
analyses and crystalline measurements of certain groups of substances 
are to be depended on, the law indicated by previous researches, that like 
forms indicate like formule, is not universally true. The paper does 
not admit of abridgement, but may be consulted in the Lond. and Ed. 
Phil. Mag. for Dec., 1838. See also Reports of the British Association, 
Vol. VI, p. 173, et seq. 


i el? ae 


60 EIGHTH REPORT—1838. . 


On the Origin of Petroleum, and on the Nature of the Petroleum from 
Whitehaven. By Prof. Jounston, F.R.S. 


The author stated that petroleum was obtained in considerable quan- 
tity from the mass overlying the three several seams of coal which 
are worked in the neighbourhood of Whitehaven. This petroleum he 
found to agree in nearly all its characters with that of Rangoon. -In 
thickness, colour, smell, and especially in the products of distillation 
alone, and with water, the two varieties agreed; and as there can be 
no doubt of the origin of the one variety—that it has been volatilized 
from the coal into the bed which covers it, and from which it now ex- 
udes—the author of the paper considered it to be almost certain that 
the wells of Rangoon must derive their supplies from subjacent beds of 
coal, and that deposits of combustible matter are to be looked for 
wherever similar sources of petroleum are met with. 


On Middletonite and some other Mineral Substances of Organic 
Origin. By Prof. Jounston, F.RS. 


The name Middletonite is given by the author to a yellow resinous 
substance found in the body of the coal at the Middleton Collieries, 
near Leeds, and in other parts of the Yorkshire and the Staffordshire 
coal fields. It is represented by the formula C,, H,, O, and is chiefly 
interesting as being in all probability the resin of certain trees of the 
carboniferous epoch, more or less altered. 


Of the Resin of Gamboge (Gambodie Acid) and its Compounds. 
By Prof. Jounston, RS. 


Prof. Johnston stated that this acid resin is represented approximately 
by the formula C, H, O, and that it forms three classes of salts, repre- 
sented respectively by 

RO + 5(C, H, O) 
RO + 10(C, H, o} 
RO + 15 (C, H; O 

This resin he also stated to be distinguished from all other known 
resins by dissolving in dilute caustic ammonia, forming a solution 
which may be diluted with any quantity of water, and which throws 
down gambodiates from ammoniacal solutions of magnesia, of the oxides 
of copper, zinc, silver, manganese, and the other metallic oxides which 
dissolve in dilute ammonia. No other resin is known to be capable of — 
giving salts from aqueous solutions. : 


On a Blue Pigment. By R. Puruirs, F.R.S., §e. 


During the meeting of the Association at Liverpool, Professor Traill 
exhibited to the chemical section a fine blue pigment prepared by add- 


TRANSACTIONS OF THE SECTIONS. 61 


ing a solution of ferrocyanide of potassium to one of chloride of anti- 
mony; at the request of the Professor, Mr. R. Phillips undertook to 
examine the pigment in question, and has communicated the following 
observations. 

** Having by me some chloride of antimony, which I employ on or- 
dinary occasions, I added to it some ferrocyanide of potassium, and im- 
mediately produced the blue precipitate. This solution had, however, 
a very slight yellow tint, and remembering that Professor Clarke had 
shown me that hydrochloric acid very much deepens the colour of 
perchloride of iron, I suspected its presence ; I therefore prepared some 
chloride of antimony from hydrochloric acid, and a protoxide which I 
believed to be pure. I obtained a perfect colourless solution, and in 
this no blue precipitate was formed by ferrocyanide of potassium. 

“ To show that the chloride of antimony, which I first employed, 
contained peroxide of iron, I decomposed a portion of it by the addi- 
tion of water; the solution gave a much deeper blue precipitate than 
before, while the oxychloride of antimony, re-dissolved in hydrochloric 
acid, gave scarcely any blue tint whatever; and the slight one which 
it did yield was evidently owing to the adhesion of a small portion of 
peroxide of iron precipitated with it ; for, again precipitating with water 
and dissolving in hydrochloric acid, this minute portion of peroxide of 
iron was almost entirely removed. 

“Tt is therefore evident, that the blue pigment is merely Prussian 
blue, largely diluted and rendered pale by ferrocyanide of antimony.” 

The author again adverts to the curious fact, already alluded to as 
pointed out to him by Professor Clarke, of the colour imparted to hy- 
drochloric acid by perchloride of iron. A few drops of the perchloride 
were rendered perfectly colourless by half an ounce of water, while 
three ounces of colourless hydrochloric acid acquired a considerable 
yellow tint by the addition of a similar quantity of the perchloride. 


On the Blue Pigment of Dr. Traill. By C. T, CoAtuure. 


Mr. Coathupe stated other experiments which confirm the conclusion 
of Mr. R. Phillips, that the colour in question could not be produced 
from pure chloride of antimony. 


A new case of the Chemical Action of Light in the Decoloration of 
Recent Solutions of Caustic Potass of Commerce. By R. MALLET, 


The author of this paper has examined chemically a large number 
of specimens of commercial caustic potass, with a view to determine 
the reality of the cause usually assigned to the deep green colour 
of its aqueous solutions, namely, the presence of manganese, in the 
state of manganesiate of potass. The colour of these solutions gra- 
dually fades in close or open vessels, and in light or darkness, an effect 
which has been ascribed, as above, to their containing mineral ca- 


> =. | 
4 « gc 


62 EIGHTH REPORT—1838. 


meleon. On careful analysis, however, the author has assured himself 
that manganese does not occur as a constituent of caustic potass, and 
that its aqueous solutions owe their colour, and the change of their 
colour, to the presence of protoxide and proto-chloride of iron in solu- 
tion; the former being held so by the presence of chloride of potas- 
sium. These, by taking up oxygen (probably from the air combined 
with the water), become further oxydized and gradually precipitate in 
combination, leaving the solution colourless, and giving rise to a new 
compound of sesquioxide and sesquichloride of iron, consisting, by the 
author's analysis, of 10 atoms of the former and one of the latter body, 
or 


(Fe, Cl,) + 10 (Fe, O,). 


It is anhydrous. Having observed that these changes took ies 
at very different rates in bottles of variously coloured glass, the 
author commenced a series of experiments on the relative effects of 
light transmitted to the solution through various media, and has found 
and recorded in ruled sheets, by curves, the results of observations 
made every two hours. In these curves, the ordinates represent time, 
and the abscissee the rate of chemical change, as marked by certain 
changes of colour. 

Means were taken to prevent inequality of temperature, or of inten- 
sity of light, in each solution exposed to a coloured ray, and some of 
the results arrived at are given in the subjoined table. 


Time of perfect 


Mode of exposure to light. Aeaniine 
Violet glass, exposed to air .......++++++e+- 30 hours. 
Violet; glass, cloged i) :a.ccs:h: aigls)sidin's9s +33 + iin iohina tee BO. cst 
Flint glass, colourless, exposed to air ........ 80... 
mini (ils os LOLI ce aps Soh ino te hi Sa fat sae Ap aap 
s oieah ‘ody of CUO, SeelahiciseceAaleksy nee 170. san 
3 .. blue gar MeveraRetEN Rises Sleeve sicisiemel OS 2 aie 
-. orange hee hee = watt, citabareeae 190). oa 
ee ree a ee ectess eenteg soda 200 
Green glass, by oxide BERD a wy wholly unchanged in 
Do. Bristol bright metal.......... colour in 200 hours. 


The rate of progressive sebionae for different rays at different pe- 
riods is very various. 

The result as to green glass agrees with Mrs. Somerville’s experi- 
ments. Ink, which Sir John Herchel found transmitted white light 
unaltered, was used to reduce all the coloured media to the same illu- 
minating power, and immersion in water to preserve the temperature 
constant. 

The author conceives that this is the first attempt that has been 
made to reduce the phenomena of the chemical action of light to nu- 
merical registration, and suggested the importance of the subject, 
upon which so little was known, and in which the observed cases were 
so few. 


ie 


TRANSACTIONS OF THE SECTIONS. 63 


Observations on the Constitution of the Commercial Carbonate of Am- 
monia. By Mr. ScANLAN. 


Having occasion some months ago to make a quantity of the “ So- 
lution of Sesquicarbonate of Ammonia,” of the London Pharmacopeeia, 
the author found, (without knowing that Dr. Dalton had done so be- 
fore,) by pouring successively small portions of pure water on large 
quantities of the salt, that saturated solutions were obtained, success- 
ively decreasing in specific gravity, and smelling less and less of 
ammonia, till all the salt was dissolved. He agrees with Dr. Dalton 
in opinion, that the commercial carbonate of ammonia is not a homo- 
geneous salt, not a sesquicarbonate of ammonia, but a mixture of car- 
bonate and bicarbonate, of which the former is first dissolved by the 
water. The irregular masses of salt which remain still retain, almost 
exactly, their original form and dimensions—they are, in point of fact, 
skeletons of the original mass, but consist solely of a congeries of cry- 
stals of bicarbonate of ammonia, from the interstices of which carbo- 
nate of ammonia has been removed by the solvent power of the water, 
if we do not proceed so far as to dissolve all. What takes place here, 
may be likened, in some measure, to the case in which the gelatin is 
removed from bone by water, leaving the phosphate of lime. Inde- 
pendently of showing the true nature of the salt, this is of some im- 
portance, as it affords us a very ready mode of preparing bicarbonate 
of ammonia without the waste, which occurs by exposure of the com- 
mercial salt in powder to the air, or without the trouble of transmitting 
a current of carbonic acid gas through its solution, as directed by the 
Dublin Pharmacopeeia. Indeed, the latter method is both troublesome 
and wasteful, for it is difficult to evaporate a solution of bicarbonate of 
ammonia without decomposition. Mr. Scanlan has found that water at 
90° or 100° decomposes bicarbonate of ammonia, setting carbonic acid 
at liberty. 


On the Blackening of Nitrate of Silver by Light. By Mr. Scantan. 


Nitrate of silver was recommended many years ago, by Dr. John 
Davy, as a test of the presence of organic matter in distilled waters. 
He showed, that if nitrate of silver in solution be added to perfectly 
pure water, it is not altered by exposure to direct sunshine; but if the 
water contain a trace of organic matter, it will become blackened. 
Mr. Fergusson, some years ago, when he had the management of the 
chemical laboratory belonging to the Dublin Apothecaries Company, 
informed Mr. Scanlan, that perfectly pure nitrate of silver is not 
blackened by long exposure to direct sunlight, but it is believed that 
he never gave further publicity to this fact than mentioning it to his 
chemical friends in Dublin at the time. In consequence of some 
observations upon the blackening of this salt, made by Dr. Aldridge, 
of Dublin, in his review of Mr. Phillips’s translation of the London 
Pharmacopeeia, Mr. Scanlan was led to make the following experiment 
upon the subject;—He took two cylinders of perfectly pure fused 


64 EIGHTH REPORT—1838. 


nitrate of silver, immediately they were cast, from the mould, and 
wrapped one of them in paper, in the usual way that this substance is 
found in the shops; the other cylinder was transferred to a glass tube, 
and sealed up hermetically, by means of the blow-pipe, without being 
suffered to come in contact with organic bodies: it was pushed from 
the mould into the tube by means of a glass rod. After a lapse of 
three days, the paper was removed from the first, and it was then 
sealed up in a tube, in a similar manner to the other. The two tubes 
were now exposed to the direct rays of the sun, and in halfan hour the 
nitrate of silver that had lain in contact with paper was blackened, while 
that in the other tube was not altered by six weeks constant exposure. 
The whole amount of blackening of the cylinder that had been papered 
was produced in the half hour. Nitrate of silver, free from organized 
matter, is sometimes blackened by exposure to the air; but this may be 
owing to the presence perhaps of sulphuretted hydrogen, accidentally 


present. Atmospheric air too is, perhaps, seldom free from organic 
matter. 


———— ey 


On the Specific Gravities of Nitrogen, Oxygen, Hydrogen, and Chlo- 
rine; and also of the Vapours of Carbon, Sulphur, Arsenic, and 
Phosphorus. By the Rev. T. Extry, M.A. 


The author of this communication first shows the bearing of his new 
theory of physics on questions relating to the combination of atoms, 
which he classes according to their supposed absolute forces and rela- 
tive spheres of repulsion. Among the consequences of this theory the 
author mentions the deduction, that “ equal volumes contain equal 
numbers of atoms,” and proceeds to show the application of tlus to the 
construction of a general table of specific gravities for chemical com- 
pounds in the gaseous form. Taking the specific gravity of air as 
unity, he shows, from comparison of the best experimental results, that 


the following specific gravities may be depended on within minute 


errors :— 


Nitrogen. . 35-36ths. Carbon* . ¢ ° 10-12ths. 
Oxygen ° ° 10-9ths. Sulphurt . ‘ 60-9ths. 
Hydrogen . ‘ 10-144ths. Arsenict . . . 104. 
Chlorine ‘ : 23. Phosphorus § . 43. 


Now these numbers, being compared with the atomic weights of the 
substances, lead to the following simple rule for determining specific 
gravities in all gaseous bodies :—Multiply the sum of the atomic 
weights of the atoms of a single group by 712, (the specifie gravity of 
hydrogen), the product is the specific gravity required. By this rule 
the following table was calculated :— 


* The number for carbon is inferred from its gaseous combinations. 

+ It is by calculation only 2°, but the author explains this difference by supposing 
the sulphur vapour to exist in single groups of three atoms each, and gives reasons 
for thinking this probable. 

+ By calculation 5}; supposed to consist of single groups of to atoms each. 

§ By calculation 22; supposed to consist of single groups of ¢wo atoms each, 


catia 


Name. Composition, ta I 

a> 

a 

I, COHESIVE COMBINA- 
TION. 

A. Carbonic Oxide ssssecsssee-|O | © sescseecscsnscessseenees 14 

’ 2. Nitric Oxide ........eeeeees On [UNivevanehs vassenee yeseaece|alith 
| 3+ Muriatic Acid .......00000. ClaliElg ssexcekta gas ceeveeeeee| 1835 
: 4, Hydrobromic Acid.........|Br | H Mii deeds .-| 402 
| 5. Hydriodie Acid ............ erltivestsexstercsnes naga 633 
| G. Fluoric Acid ..........0005 BD vit vag css enes ar eee 9} 
| 7. Sulphuret of Mercury...... Si] Hes He. sccsconseeses 773 
8. Common Air .........602./0 | N| N| NN...) 142 

Il. SINGLE GROUPS, 

9. Cyanogen secressecceoresees NC or N (Cy) Nu... eeeeeee 26 
{10. Chloride of Sulphur ...... C1S or Cl (S3) Cl......... 68 
t 11. Chloride of Mercury ...... Cl Hg or Cl (Hgg) Cl .../136 
‘ j12. Bromide of Mercury ...... Br Hg or Br (Hg,) Br ...|180 
\13. Iodide of Mercury .........|[Hg, or I (Hgo) I «ss. 226 
‘14. Fluoboric Acid .........+.- FB or F (Bg) F csssseseeees 34 
15. Nitrous Acid ....s..s.s00+0- Oz N or N (04) N vevseeeee 46 
116. Peroxide of Hydrogen ...|HO, or H (02) H ....... iy 
py. Persulphuret of Hydrogen |HS, or H (Sj) H ......... 33 
'{18. E. Davy’s Carb. of Hydro.|HC, or H (C2) H ......... 13 
i] 9. Faraday’s Carb, of Hydro.’ |Hg Cg <....,...ssscaseessenese 39 
‘20. Olefiant Gas ............008 H.C or H, C, H......eeeeee 14 


M4. Naphthaline ............6+. Hg (Coaagcseresusncncossocsas 64 

25. Petrolenc.......cccesseeeee exs[ tig) Cafiensebesaedesacconcnes oa 128 

G. Camphene ..........0cce000s Hg Cy .sseeee tenercevoveeen +s] 68 

7. Oil of Turpentine ....... ga Liai@e stxphcaseeecatacccesceas| SO 

ydrocarb. of Chlorine ...|H, C1C, or H, C1C, H ...| 50 

29. Arsenious Acid ............ As; Oy or O, OAs:, 0 «..1200 

30. Chloride of Silicon......... Cl, Si, or Cl, Si, Cl ......| 88 

31. Fluosilicic Acid .........4.. F, Si, or F, Si, F  ......0e. 52 
H32, Aikarsin ... ....,...0:00+000|Hg Cy As, or Hy C, Hy As, 

| Py Oi>isesanverves soveeseee[ 106 

III, DOUBLE GROUPS. 
I53, Water Mipwanadecetveicediees ofH (O) Heweseseeee Sadoorssass 9 
‘YoL. Vil. 1838, F 


f 
| 
i) » 


TRANSACTIONS OF THE SECTIONS. 


Sp. gr. 
By Cal. 


1:8055 
4°7222 
9°4444 
12°5 
15°6944 
2°3611 
371944 
1°1805 
22916 
9027 
2°7083 
9722 
1-9444 
2°9166 
2°8472 
4°4444 
8°8888 
4°7222 
5°5555 
3°4722 
13°8888 
61111 
3°6111 


73611 


Air= 1, 
By Expt. 


1°8064 
4-70 
9-439 
12°362 
15°67 
273622 
371764 


} 


65 


A Table of Chemical Compounds in the Gaseous Form. 


Authority, 


Berzelius. 

Davy; Thomson. 
Thomson. 
Turner, 

Gay Lussac. 


Dumas. 
The unit. 


Gay Lussac. 


Dumas. 
Mitscherlich. 
Ditto. 

Ditto. 
Thomson. 
Gay Lussac. 


these are decomposed by a 
degree of heat below the 
boiling point, 


9027 |E. Davy. 


2°776 
9709 
191 
3°0555 
2°833 
4°528 
9°415 
4:767 
5°0130 
374434 
13°6695 
5-939 
3°600 


6°516 


*6235 


Faraday. 
Thomson. 
Faraday. 
Ditto. 
Saussure. 
Dumas. 
Boussingault. 
Dumas, 

Gay Lussac. 
Ditto. 
Mitscherlich. 
Dumas. 
Thomson. 


Bunsen, 


Gay Lussac. 


66 


EIGHTH REPORT—1838. 


Table continued. 


Name. Composition, Be I 
55 

34. Sulphuretted Hydrogen...|H (S) H ..cscccesseseeseeeees 1 
35. Carburetted Hydrogen ...|H (C) H....s.esseseesseeees 7 
36. Telluretted Hydrogen...... As (Qe) MELA tao eecesasteaccesss 33 
37. Selenuretted Hydrogen ...|H (Se) He. ccsssssssesseeeees 41 
38. Inflble. Phosphtted. Hyd. |H (P) H ...seseeseesseseecoes 17 
39. Carbonic Acid......... Deere OM (ONO) odeancataxsedescb sees] 22 
40. Sulphurous Acid...... TNS UICONOS) SG) sdeccsceqcccsdasbdese 32 
41. Deutoxide of Chlorine ...|O0 (Cl) O.....seccsecsseeesoee 34 
42. Protoxide of Chlorine .../C1(O) Cl ......... pudataee 44 
43, Bichloride of Sulphur ...|Cl (S) Cl....c.seseeseeneees e-| 52 
44, Bichloride of Carbon...... CU (C)\WGU acc nearctecsas one 42 
45. Chloride of Manganese ...|Cl (Mn) Cl.......... cre Re 64 
46. Chloride of Selenium ...... Cl (Se) Cl ......... sas cakes 76 
47. Borochloric Acid ......... KSC) lye. <casayencsapyesses 44 
48. Chlorocyanic Acid ......... NICO CGT GaBeRrecetR rE Coro: 31 
49, Hydrocyanic Acid ..,...... DMC) Ete sctsaasacurtsn teaser 133 
50. Bisulphuret of Carbon ...)S (C) S serseeeereesees at ay 38 
51. Nitrous Oxide .......+++++ Srcl (ON creascnsantdenes wase's |b 22 
52. Protochloride of Mercury |Hg (Cl) Hg ...seeceseeeeee 118 
53. Protobromide of Mercury |Hg (Br) Hg .....seeeeecees 140 
54. Bromide of Sulphur ...... Wa (GS) Eph caccesessseskeqtes aes 96 
55. Sulphuric Acid ......sseee COMER Wi eoctrence 40 
56. Selenic Acid ..seereeseeeeee O (SeO) O....... nev gue cages 64 
57. Phosphuretted Hydrogen |H (PH) H ......sseseeesesees 173 
58. Arsenuretted Hydrogen...|H (AsH) H  ...cessesseseee 393 
59. AMMONIAr se erereesensereees H (NH) EH... ccsceces sense «|. 83 
60. Chloride of Phosphorus ...|Cl (PC1) Cl......... sudveneer| S710) 
61. Chloride of Arsenic ......|C1 (As Cl) Cl.........se0e. 92 
62. Sesquichloride of Carbon |Cl (CCl) Cl......20. EAC 60 
63. Chlorocarbonic Acid ...... Cl (CO) Cl......... Secepane 50 
64. Light Carburetted Hydr. |H (CHa) H.......s-.0- Perel be bts 
65. Perchloride of Tin ...... gacl@li (em Gls) Clieeeevcauesneas 130 
66. Perchloride of Titanium.../Cl (Ti Clg) Cl.......eceereee 98 
Gy: Chilaraltiwscsstesaessseessases Cl (Cl C, HO) CL......... 743 
68. Infl. Gas of Dr. Thomson |Cl (C1 CH) Cl ......ee00--| 61 
69. Chloroform ...cecresseseeeees Cl (Cl CH) Cl...ccsecceeeees 603 
70. Muriatic Methyline ...... ED (Gl CH) Fy cevececccsccons 253 
71. Sesquiodide of Arsenic .../I (As3) I,.....+00-+. eacaetere 


Sp. gr. 
By Cal. 


1:1805 

4861 
2:2916 
2°8472 
11805 
15277 
2°2222 
2°3611 
3°0555 


36111 
29166 
4:4444 
512777 
3°0555 
2°1527 

9375 
26388 
15277 
81944 
9-72.22 
6°6666 
27777 
44444 
12152 
2:7430 

5902 
48611 
6°3888 
41666 
3-4722 

“5555 
9:0277 
6°8055 
51736 
4:2361 
4:2013 


1:7708 


240 |16°666 |15°64 


Air = 1; 
By Expt. 


Authority. 


1:1912 |Thenard. 
‘490 |Dumas. 
2:292 |Brande. 


Rose. . 
Thenard. 
Thomson. 
Thenard. 

Gay Lussac. 
Dumas. 


1:1935 
1523 
2-221 
2°346 
3:0 
3°67 


3°942 
2°153 


Dumas. 
Ditto. 

‘9385 |Thenard. 
2°6447 |Gay Lussac. 
1:5269 |Thomson. 
8:204 |Mitscherlich. 
9665 |Ditto. 
3°0 Mitscherlich. 
1°214 
2°695 

5967 
4°875 
6°295 


Dumas. 

Ditto. 

Biot & Arago. 
Dumas. 

Ditto. 


3°472 
5550 
91997 
6°836 
50 
41757 
4:2 
1°736 


Henry. 
Thomson, 
Dumas. 
Ditto. 

Ditto. 
Thomson. 
Dumas. 
Ditto. 
Mitscherlich, 


TRANSACTIONS OF THE SECTIONS. 67 


Table continued. 


! bn Sil Sp. gr. | Air=1. r 

I Name. Composition, ss By Cal. | By Expt. Authority. 
i] 

\yo. Witwig ACid «....cesceoseee... BY TORY | reenter 54/375 | 3°75 (Henry. 

73 Hyponitrous Acid ......... Wil Oa MN ec teecgcatave e.| 38 | 2°6388] 2°6388 pune from No. 

‘W74. Pyroxylic Spirit ...c..0.--. MY (EOC) Hesoyscscl tases. 16 | 1-1111| 1-115 |Brande. 

75. Pyroacetic Spitit........... H, C (H, OC) Hy C ...... 29 | 20138] 2019 [Dumas. 

76. Protohydrate of Methyline . C (H, C) HO ......... 23 | 1:5972| 1:60 |Dumas, 

77. Sugar Anhydrous .......-. H, C (0, C) Hy C....... «| 36 | 2°5 Solid. 

MBB, Alcohol s.0s..c.f..ceesees H, C (H, 0) Hy C ........| 23 | 1:5972| 1°6133 |Gay Lussac. 
79. Mercaptan .....ssscseccesees H, C (H, 8S) Hy C......... 31 | 21527} 2°326 |Bunsen. 
A Ghai F550... Sande HAC) (By C) He O..degy208 21 | 1-4583| 1458 |Henry. 

81. Muriatic Ether ............ H, C (Cl H) H, C......... 325] 2°2569| 2°219 |Gay Lussac. 
82. Hydriodic Ether.....,....... H, C (1H) Hy C....ecseeeee 773| 53819 | 5°4749 |Ditto. 
[83. Aldehyd .......scsseeceeees PILG) (OR iE oS <crseaty< sans 22 | 1-5277| 1532 |Liebig. 
'|84. Acetic Acid............cc0008 H, C (C, 03) Hy C ......] 50 | 3°4722| 3:067 |Dumas. 
BP RION CL ch ccccenssiscocsesetex H, C,(H, O) Hy Cy ...... 37 | 2°5694| 2°5860 |Gay Lussac. 
Bir CUE be vcveictssbecensceaes Hg Cy (C) Hy Cg saseeeees 34 | 2°3611} 2°385 |Dumas. 

\87. Oxalic Bther .......c000. H, Cy (Hy 04 Cz) Hy C, | 73 | 5-0964| 5-087  |Ditto. 
88. Carbonic Ether ............ H, Cy (Hy 03 C) Hy Cy...| 59 | 4:0972| 4-243 |Ettling. 
(89. Gnanthic Ether ............ Hy Cy (Hag O3 C14) Hy Cy /150 [10-4166 |10°4769 |\Delachamps. 
190. Benzoic Acid ......... jane Gs Or) ds C; | H.C 
} (CO3) Hy C....0cccncseees 60 | 4°1666| 4:27 |Dumas. 
I j1. Benzoic Acid, concentrat. |H, C; (H, i O;) Hy C, 120 | 8°3333 | 8°352 interred from 85 
} and 95. 
92 2. Paranaphthaline ..........+. By @> (1 |G) Hype an: 96 | 6°6666| 6-741 |Dumas. 

}]93. Camphor........sseseccceeeee Hg Cs (O) Hg Cy .wsseneee 76 | 5:2777| 5:29 |Ditto. 

94, eke ee H, 5 (A, ae H, C, | Hy 
i C (C, 03) Hy Co... 433] 3:0208| 3:067 |Ditto. 
5. aia BieHeteecee< a, she-=s H, C, (H, O) H, C.—H, 
Cz (Hy 03 C1) Hy Cy...| 783| 5°4513| 5-419 |Ditto. 
6. Nitric Ether ...... dtage tit H, C, CH, 0) H, C,| N 
, (OWNING SA he vecoootne: 373| 2°6041| 2-627 |Ditto. 
97. Sulphur Vapour ......004.4-|S3 see. Pee taetiet estes -».| 96 | 6:6666| 6:648 |Mitscherlich. 
98. Phosphorus Vapour ......|Py sessssseseeees Ea Rsk aden 64 | 4:4444]| 4-327 |Ditto. 
99. Arsenic Vapour .........++. COE I eR atts hs assnwips 152 |10°5555 |10-362 |Ditto. 


68 BIGHTH REPORT—1838. 


On Chemical Combinations produced in virtue of the presence of other 
bodies which still remain. By Rev. T. Extry, M.A. 


Mr. Exley points out in this paper the application of his theory to 
the explanation of those cases in chemistry where powerful affinities 
between bodies are brought into activity by means of other substances 
which are present and continue to exercise the same energies. Berze- . 
lius attributes this to a peculiar force, which he calls catalytic, and Mr. 
Exley takes four examples to show how these phenomena receive an ex- 
planation in conformity with his general view of atomic centres of force. 

The first case is that of the combination of hydrogen and oxygen, 
effected by the presence of clean platinum. ‘“ Since metals are simple 
bodies and dense solids, the theory recognises their atoms as having 
small spheres of repulsion, and those of platinum must be very small 
because of the great density of the metal: hence, the atmosphere of 
ethereal matter belonging to this metal is very dense, being more dense 
as the square of the radius of the sphere of repulsion is less and as the 
atomic weight is greater. For this reason the oxygen can approach ex- 
tremely near to the atoms of platinum, and yet not combine with them 
by reason of that dense atmosphere ; and the hydrogen being drawn 
close on them the reunion in question occurs, the generated steam 
escapes, heat is evolved, and the process advances till ignition is pro- 
duced.” , 

The author examines in succession three other cases of supposed 
peculiar actions, and explains them on the principles of his theory : 

The conversion of starch into sugar by the action of a weak solu- 
tion of sulphuric acid. 

The conversion of sugar into alcohol by the action of barm. 

The conversion of alcohol into ether by the action of sulphuric 
acid. 


On an Improvement in the Manufacture of Tron, by the Application of 
Gas obtained from the decomposition of Water. By Joun SAMUEL 
Dawes, of Bromford and Oldbury Ironworks, near Birmingham. 


Mr. Dawes has attempted to obtain a heating effect approaching in 
intensity to that which is produced by the oxy-hydrogen blow-pipe, but 
upon a scale sufficiently large to be available in the smelting of iron. 

Hydrogen gas, in addition to its great inflammability, exhibits, when 
applied to the above purpose, a purifying property in a high degree, so 
that the most sulphurous materials may be used with advantage, and 
metal of good quality be produced. There can be little doubt (Mr. 
Dawes thinks) as to the value of hydrogen thus applied ; the question 
would rather be, Can the gas be obtained at a sufficiently cheap rate so 
as to make the use of it profitable ? This, he thinks, may now be con- 
fidently answered in the affirmative. The method of proceeding is as 
follows. Jets of steam are made to pass through red-hot cast-iron 
pipes filled with small coke or charcoal ; (the riddlings from the coke 
hearth answer the purpose, and are of little value ;) decomposition 


BS ty 


TRANSACTIONS OF THE SECTIONS. 69 


immediately takes place. The carbon of the coke combines with the 
oxygen of the steam, forming, in the first instance, carbonic acid, 
which, by passing on through a further portion of the red-hot carbon, 
is converted into carbonic oxide; the hydrogen gas, together with the 
oxide before-mentioned, is applied to the furnace by means of a jet 
inserted within the blast-pipe tongue; the pressure upon the gas, of 
course, being equal to that upon the blast. The pipes require to be 
replenished with the brays about every twelve hours, which is con- 
veniently effected by means of a plug fitted to the top of each of them. 
At first some diffficulty arose from destruction of the pipes; but as 
the melting point of cast-iron is so much higher than the temperature 
required to decompose water, it was evident that the cause of the mis- 
chief lay in the construction of the heating furnace. This ha8 been 
remedied, and the apparatus seems now to be very durable. The pre- 
sent one at Oldbury has been in operation for some months, and the 
pipes are apparently little the worse for wear. The quantity of fuel 
required to keep them hot is from twelve to fifteen cwt. of small coal 
for twelve hours ; and as the steam is obtained from the engine-boilers, 
and the fireman of the hot-air apparatus has time enough to attend to 
it, the expense, with the exception of wear and tear, is a mere trifle. 
The wear and tear, in every probability, will be very moderate, and 
Mr. Dawes has sufficient reason to conclude that the cost will not be 


‘more than three or four shillings for every hundred thousand feet of 


gas, every foot of which is, of course, equivalent to a certain quantity 
of fuel. Various experiments have now shown not only that the qua- 
lity of the iron is very much improved by this process, but that the 
producing power of the furnace, at the same time, has greatly increased. 
In conclusion, Mr. Dawes observes, that any advantages it may be 
found to possess in the smelting of iron must be equally valuable in 
the reduction of other metals. 


On the Influence of Voltaic Combination on Chemical Action. 
By Dr. ANDREWS. 


In dilute sulphuric acid, composed of one atom of the dry acid and 
eight atoms of water, the solution of distilled zinc is permanently acce- 
lerated, by connecting it with a plate of platina, immersed in the same 
liquid, so as to form a voltaic combination. In acid, containing seven 
atoms of water, the ordinary action is at first increased, and afterwards 
rather diminished by contact with platina. But when zinc is heated in 
acid, containing less than this quantity of water, the connexion with 
platina transfers the evolution of gas, from the surface of the positive 
to that of the negative metal, and at the same time diminishes its 
quantity, and consequently retards the rate of solution of the zine. 
The formation of a galvanic circle exerts, therefore, a reverse effect on 
the solution of zinc in sulphuric acid containing more or less than 
seven atoms of water. The principal circumstances which influence 
these results are the adhesion of the hydrogen gas to the surface of the 


70 EIGHTH REPORT—1838. 


zinc ; the formation of sulphate of zine, which is greatly facilitated by 
the presence of seven atoms of water in union with each atom of acid 
(that being the number of atoms of water of crystallization contained 
in it); and, lastly, the proper action of the voltaic circle, which tends 
to diminish the solution of the zinc. In dilute acid, the first circum- 
stance retards the action on the zinc alone, and the second facilitates 
its solution ; then the platina surface enables the hydrogen to escape. . 
But in the stronger acid, the voltaic association impedes the solution 
of the zine, partly from the evolution of gas being transferred to the 
platina, and thus the saturated liquid being allowed to accumulate 
around the zine plate, and partly from the real effect of the galvanic 
combination. That the proper tendency of a voltaic circle is, to dimi- 
nish the chemical action of the solution on the electro-positive metal, 
the author endeavoured to show, from the consideration, that in or- 
dinary solution the electricities thus developed have only an indefi- 
nitely small portion of liquid to traverse, while in voltaic solution their 
reunion can only be effected by passing across a column of variable ex- 
tent, and composed of an imperfectly conducting substance. And, as 
the action is greater the nearer the plates are to each other, that action 
ought to attain a maximum when the distance between the plates 
vanishes, provided this condition could actually be realized. 


On the Construction of Apparatus for solidifying Carbonic Acid, and 
on the Elastie Force of Carbonic Acid Gas in contact with the liquid 
form of the Acid, at different Temperatures. By Ropert ADDAMS. 


Mr. Addams prefaced the communication by adverting to the ori- 
ginal production of liquid carbonic acid by Dr. Faraday, in 1823, and 
also to the solidification of the acid by M. Thilorier, and then exhibited 
three kinds of instruments which he (Mr. Addams) had employed for 
the reduction of the gas into the liquid and solid forms. The first 
mode was mechanical, in which powerful hydraulic pumps were used 
to force gas from one vessel into a second, by filling the first with 
water, saline solutions, oil, or mercury; and in this apparatus a 
“ gauge of observation” was attached, in order to see when the vessel 
was filled. The second kind of apparatus is a modification of that in- 
vented and used by Thilorier. The third includes the mechanical and 
the chemical methods, and by which, as stated, a saving of a large 
quantity of acid formed in the generator is effected; whereas by the 
arrangements of Thilorier’s plan, two parts in three are suffered to rush 
into the atmosphere, and are lost. With this set of instruments are 
used two gauges of observation,—one to show when the generator is 
filled with water by the pumps, and consequently all the free carbonic 
acid forced into the receiver ; and the other to determine the quantity 
of liquid acid in the receiver. Mr. Addams likewise exhibited other in- 
struments for drawing off and distilling liquid carbonic acid from one 
vessel into another, and mentioned some experiments which were in 
progress, and especially the action of potassium on liquid carbonic 


TRANSACTIONS OF THE SECTIONS. 71 


acid,—an action which indicated no decomposition of the real acid, 
but such as implied the presence of water, or a hydrous acid. A table 
of the elastic force or tension of the gas, over the liquid carbonic acid, 
was shown, for each ten degrees of the thermometer, beginning at 
zero, and terminating with 150 degrees. The following are some of 
the results :— 


.inch, | Atmospheres of 
Degrees. | lb. per sq. inch Lblbe each: 


0 279-9 18:06 
10 300- 20: 
30 398-1 26°54 
32 413-4 27°56 
50 520:05 34:67 

100 934:8 62:32 
150 1495-65 99-71 


Mr. Addams announced his intention of examining the pressure at 
higher temperatures, up to that of boiling water, and above ; and as- 
serted his belief that carbonic acid may be profitably employed as an 
agent of motion—a substitute for steam,—not directly, as had been 
already tried by Mr. Brunel, but indirectly, and as a means to circulate 
or reciprocate other fluids. The solidification of the acid was shown, 
and the freezing of pounds of mercury in a few minutes, by the cooling 
influence which the solid acid exercises in passing again to the gaseous 
state, 


—— 


On a New Process for Tanning. By WittrAM HERAPATH. 


The author, after noticing the impediments to a perfect accomplish- 
ment of the three great objects of the tanner, viz. to make the skins of 
animals insoluble, imputrescible, and impermeable to water, describes a 
new process, by which these objects are accomplished at a less cost 
than that of the old methods. In the ordinary process, the harder 
fibres of the skin are perfectly tanned; but the gelatine, which, if re- 
tained, would be of the greatest value in rendering leather imperme- 
able to water, disappears from the product, or is seen as an injurious 
yellow coat on the surface. In reasoning on the difficulties experienced 
by tanners, Mr. Herapath was brought to the conclusion that they were 
occasioned by the force of capillary attraction; and finding that the or- 
dinary modes of applying pressure, handling, &c. were expensive and in- 
sufficient, he determined to try the effect of rolling the hides, connected 

together as an endless band. 

“ Tf I wish to tan one hundred hides a week, I should have eight pits, 
over each of which would be affixed a pair of rollers; the upper ones 
to be loaded by weights fixed on their levers. For each pit fifty hides 
or butts would be made into an endless band by ligatures of twine ; 
upon introducing each band between a, pair of rollers, each hide would 
be in succession pulled from the bottom of the pit, squeezed by the 


72 EIGHTH REPORT—1838. 


rollers, and then returned again into the pit for a fresh supply 
of tanning liquor; such liquor becomes exhausted, about two degrees 
of the barktrometer, in twenty-four hours, when it is pumped to 
the next pit backwards of the series ; and, by the time it arrives at the 
last pit, (eight days,) it will have lost from 16 to 20 degrees by the 
same instrument. The eight pairs of rollers require one-horse power 


to work them, and two boys of 2s. 6d. a week each to superintend . 


them; when two bands or one hundred hides will be taken off weekly, 
as one month is sufficient for them to be on the rollers. They are now 
laid by in strong solutions for another month, when they are found to be 
completely tanned; weighing 10 per cent. more than if they had been 
operated upon in the cld way, while the leather has more soft elasti- 
city, and is ten times more impervious to water. 

“ The levers are loaded according to the state of tannage, and the 
liquors are changed once a day, making twenty-four changes in the 
whole, which is about one-fourth of the number formerly used.” 

The author entered into a minute statement of facts to prove the 
practical advantages of the process thus briefly described, in respect of 
cheapness, expedition, quick return of capital, and quality of the pro- 
duct. 


On some New Salts of Mercury. By Witi1am West, Leeds. 


This paper describes the composition and properties of some salts, 
composed of bicyanide of mercury, with the haloid salts of potassium. 

As these salts had, without Mr. West’s knowledge, been previously 
formed by other chemists, it is unnecessary to detail his experiments, 
which confirm former researches as to their composition. The author 
observed that the pearly lustre of some of these crystals, especially those 
from the bromide, was such that they might probably be employed in 
place of the scales of the Bleak, for the manufacture of artificial pearls, 


On a New Compound of Carbon and Hydrogen. By WiL11AM 
Mavucuam, Lecturer on Chemistry at the Royal Gallery of Practi- 
cal Science, London. 


The compound in question is produced when. the electrodes of a vol- 
taic battery are armed with charcoal points, and these points introduced 
into a vessel of distilled water. The points should be attached to the 
copper-wire electrodes by means of platinum wires. On bringing the 
charcoal points together under the water, so as to produce the elec- 
trical spark with as little interruption as possible, the water undergoes 
decomposition, carbonic oxide is produced, and a compound, not pre- 
viously noticed, consisting of carbon and hydrogen, is at the same time 
formed. Neither hydrogen nor oxygen gases are obtained as happens 
when the action is electrolytic. 

The compound under consideration is of an oily nature ; it imparts 


a: 


- 


TRANSACTIONS OF THE SECTIONS. 73 


a very peculiar and unpleasant odour to the water, which becomes im- 
pregnated with it as it is formed ; when kept for some time the liquid 
loses its odour, and there is a precipitate of carbonaceous matter. This 
spontaneous change takes place whether the liquid be exposed to the 
air or kept in a stoppered phial. 


On a Mode of obtaining an Increase of Atmospheric Pressure, and on 
an Attempt to liquefy Hydrogen and Oxygen Gases, with accom- 
panying Apparatus. By Witt1am Mavueuan, Lecturer on Che- 
mistry, Royal Gallery of Practical Science, London. 


The apparatus consists of a strong glass tube, bent in the form of the 
letter U, having a platinum wire attached to a brass cap passing into each 
leg. The glass tube is ground at each end, and the ground surface of 
the brass cap is held down by means of screws, a collar of leather being 
interposed to make the whole air-tight. Water being introduced into 
the tube, and the tube closed, the wires are to be attached to the elec- 
trodes of a sustaining battery. The water then undergoes decomposi- 
tion, and the oxygen and hydrogen gases evolved are retained in the 
tube, the pressure on the gases being increased in proportion to the 
time the action is going on. 

The pressure thus obtained may be carried to such an extent as to 
burst the strongest glass tubes that have yet been employed in the ex- 
periment. 

By making the experiment with the assistance of cold, the author of 
the paper anticipates that both hydrogen and oxygen may be liquefied. 

The tube is not to be completely filled with water, and it will be ne- 
cessary to have the water slightly acidulated with sulphuric acid. 

Should we not be able to succeed in liquefying hydrogen, oxygen, 
&c., we have, nevertheless, a mode of obtaining increased gaseous press- 
ure, which, with a slight modification of the apparatus, that will readily 
suggest itself to those experienced in manipulation, will enable us to 
liquefy those bodies which pass from the aériform to the liquid state at 
comparatively low pressures. The same process may also be rendered 
available for other purposes, where increased pressure becomes re- 
quisite. 


— —_—_— 


On the Water of the Dead Sea. By Joun Murray, F.L.S. Se. 


Having had an opportunity of examining chemically the waters of the 
Dead Sea, the author discovered several substances which he supposes 
to have escaped the attention of those chemists who have already sub- 
mitted them to analysis. He described the effect of many re-agents in 
testing the constitution of the water, which exhibited, after repose, 
strong signs of sulphuretted hydrogen. There was no trace of iron. In 
addition 1o lime, magnesia, sulphur, &c., the substances which the au- 
thor supposes himself to have been the first to detect in this celebrated 


74 EIGHTH REPORT—1838. 


water are, iodine, boracie acid, ammonia, silica; selenium. He also 
found bromine. The waters of the Jordan are strongly contrasted with 
those of the Dead Sea; for they yielded to Mr. Murray only minute 
traces of lime and magnesia and muriate of soda. 


Observations ant Experiments made upon an Instrument termed a 
Magnet-Electrometer. By Lieut. Morrison, RN. 


In this communication Lieut. Morrison repeats the assurance that in 
the instrument of his invention the magnet deflects to the east when 
the air is posttively electrified, and to the west when negatively elec- 
trified. 

He also states the results of some examinations of the action of the 
instrument, made to determine the validity of an opinion which had 
been advanced, that the deflections in this instrument depend on the 
hygrometric state of the suspending string. The author declares that 
the same phenomena happen when a fine silver wire is used instead of 
the string. 


On the Production of Crystals of Silver. By Tuos. E. BLAcKWALL. 


Having observed nearly two years since in his writing-desk, some 
small crystals of silver which were firmly fixed upon a green substance 
like malachite, the author inferred, from seeing also a piece of brass in 
his desk, which fitted to the green mass, that there had been galvanic 
action generated by the zinc and copper of the brass, and that by its 
influence the nitrate of silver had been decomposed, and thus the silver 
crystals formed. 

He describes experiments which he had instituted to test the truth 
of this view, and mentions the production of very similar crystals by 
the aid of corresponding metallic combinations. 


GEOLOGY. 
Observations on the Newcastle Coal-field. By Joun Buppwe, F.G.S. 


This elaborate memoir, comprising a detailed account of the most 
interesting phenomena of the coal formation round Neweastle, was di- 
vided into several portions, entitled, 


Observations on the Newcastle coal-field. 
Strata of the Newcastle coal-field. 

Description of the sections of the seams of coal. 
Foreign substances in coal. 

Hitches and troubles. 

Dykes and faults. 


TRANSACTIONS OF THE SECTIONS. 75 


Numerous coloured sections, drawn to a large scale, and geological 
maps, were exhibited in illustration of the statements in the memoir. 
It has been found impracticable, without the aid of engravings from 
these beautiful and valuable drawings, to convey any proper notion, 
within moderate limits, of the mass of curious facts made known by 
this communication. It appears, indeed, the less necessary to attempt 
an analysis of Mr. Buddle’s Essay, since it is understood that the 
author proposes to communicate it to the Natural History Society of 
Northumberland, Durham, and Newcastle on-Tyne, to whose Trans- 
actions he has previously consigned several important sections of the 
strata of the Newcastle coal-field. The following passages are ex- 
tracted from the first section of the memoir. 

“ On referring to the line of the crop of the coal, and the line of the 
axis of the general dip of the strata, it would appear that this field of 
coal, so far as it has hitherto been explored, although traversed by 
various undulations and large faults, forms only a portion of an im- 
mense trough or basin, the south-western, western, and northern mar- 
gins of which we have yet only been able to trace. But as the strata, 
so far as they have yet been explored, in the line of the dip under the 
magnesian limestone, are conformable, there is reason to conclude that 
the seams of coal extend far under the German Ocean before they 
rise at the opposite margin of the basin, if that should be their form, 
or are cut off by the extension of the magnesian limestone. 

“ A great many seams of coal are found in this extensive district, 
but they differ in number, character, quality, and thickness, in its 
several portions, and it is seldom that more than five of workable 
thickness co-exist, and it frequently happens that not more than one 
or two occur in the same locality. In Monkwearmouth colliery, for 
example, we find 31 seams of coal sunk through in a depth of 264 

_ fathoms 4 feet 9 inches, containing an aggregate thickness of 47 feet 
2 inches of coal, (including the foreign substances with which the 
several seams are interstratified, ) only one of which has yet been found 
of workable thickness and merchantable quality. Those seams vary 
in thickness from an inch and a half to 6 feet 2 inches and a half. In 
Backworth Colliery 283 beds have been sunk and bored through within 
a depth of 206 fathoms 0 feet 11 inches from the surface, comprising 
45 seams of coal, of the aggregate thickness of 60 feet 1 inch, inclu- 
ding the foreign substances with which the coal is interstratified. Of 
these seams only two or three can be considered of workable thickness 
at the present era.” 

It appears that the coal seams of the Newcastle district are very 
variable in respect of the presence and thickness of interstratified shales 

and sandstone called “ bands.” The most remarkable of these lies in 

the High Main coal, and is called the “ Heworth Band,” from the 
place of its first discovery. The direction of its Northern edge is 
about N. 80° E. by compass. From Felling Colliery, towards the 

N.E., it traverses Walker, Hebburn, Bewick, Perey Main, and Colling- 

wood collieries, to the outcrop of the seam near North Shields ; and in 
| the S.W. direction from Felling Colliery, it passes through Sheriff 


76 EIGHTH REPORT—1838. 


Hill, Team, Urpeth, Stanley, South Moor, and Lanchester Common 
Collieries, probably to the outcrop of the coal in that direction. 

“ This band first shows itself as a mere parting in the coal; gene- 
rally at about 10 inches above the Black-band, which is incidental to 
the seam. By almost imperceptible degrees it goes on increasing till 
it reaches the thickness of 3 inches, and becomes a confirmed slate 
band of a dark gray colour. A little before it attains this thickness, a 
three-inch layer of coarse ‘ brassy coal,’ (coal mixed with iron pyrites), 
appears at the bottom of the under division of the seam, separating it 
from the bottom coal; and it is worthy of remark, that this layer of 
‘ brassy’ coal almost invariably accompanies the Heworth Band. From 
3 inches in thickness the band goes on thickening more rapidly to 12 
inches, after which it goes on in a still more rapid ratio to 10 and 12 
feet; finally dividing and destroying the seam as it goes southward.” 

«“ When the band approaches the thickness of 12 inches, it changes 
to a much lighter hue, and inereases in hardness; and as it goes on 
thickening it becomes arenaceous, and finally passes into a stratum of 
sandstone, 7 fathoms thick, in one of the pits of Washington Colliery, 
while in another of the pits of the same colliery, it forms a variety of 
beds of sandstone and gray and black metal stone.” 

Considering the extent of the Newcastle coal-field, but few whin 
dykes occur, as only three or four of any considerable magnitude have 
yet been discovered. These are the Coaly Hill, the Hamsterly Com- 
mon or Hett Dyke, the Cockfield Fell Dyke, and the Acklington Dyke. 
The first of these dykes is the subject of a notice of Mr. Buddle in the 
Transactions of the Natural History Society of Northumberland, Dur- 
ham, and Newcastle on Tyne, (vol. i.,) and it is remarkable for its 
undulatory character and its limited vertical depth. In fact, levels 
have been driven across the presumed plane of its fissure, both above 
and below the really existing vertical mass of whin-rock ; of this Mr. 
Buddle furnishes ample proof from colliery workings, which also dis- 
close the curious vertical divisions which exist in the dyke. 

The dislocations of the strata called ‘slip dykes,’ or ‘ faults,’ are 
infinitely more numerous than whin dykes in the great coal-fields of 
the Tyne and Wear, All the principal faults and whin dykes were 
represented by Mr. Buddle on a map, and minutely described in the 
paper from documents of the most undoubted accuracy. Accurate 
sections illustrating these phenomena, were drawn on a magnificent 
scale, and have been copied in a reduced form for publication along 
with the original memoir, which is expected to appear in the Newcastle 
Transactions, already rich in contributions to the geology of the coal 
formation of the Tyne and Wear, from the stores gathered in Mr. Bud- 
dle’s extensive mining experience. 


On the Berwick and North Durham Coal Fields. 
By D. Minne, F.R.SLE. 


The strata of the Berwick and North Durham coal field consist of 


ore ST Te Per ae 


Sate y si 


TRANSACTIONS OF THE SECTIONS. a7 


sandstones, limestones, coal, and the strata usually existing in all coal 
fields. They underlie the millstone grit rocks which crop out at Ale- 
mouth, and they overlie thick beds of a red conglomerate, accompanied 
by slaty red sandstones, which rest on the Lammermuir Hills towards 
the north, and on the Cheviot towards the west. There are altogether 
fourteen beds of workable coal, the thickest of which contain about six 
feet of pure coal. There are seven beds of marine limestone, each on 
an average fifteen feet thick. This coal field is intersected by four 
greenstone dykes, all of which run in a direction E. and W., and all of 
which become thinner towards the west; two of them run severally 
about eight miles. The Kyloe hills consist of greenstone, which is 
stratified, and forms part of the whin sill that runs through Northum- 
berland. ‘The strata are in the form of a basin, having been elevated 
on two sides by the porphyry of Lamberton and Cheviot hills. But the 
phenomena of the district afford clear evidence that there have been 
two periods when the porphyry was ejected, one of these periods being 
before the deposition of the stratified rocks, and the other after the de- 
position. This evidence is afforded by the conglomerate under the coal- 
measures, which in many places contains fragments of the Lamberton 
and Cheviot porphyries,—and by the verticality of these coal-measures 
in other places where they are in contact with the porphyry. The 
slips or dislocations caused by these convulsions were pointed out and 
described, with reference to a map and sections. The direction of these 
slips was stated to be generally coincident with the dip and rise of the 
strata, so that where the strata dip the same way continuously over a 
great extent of country, they are all parallel ; and where they are inthe 
form of a basin, they converge to the trough of it. 

It was mentioned, that organic remains of various kinds were found 
in the strata of the district. Remains of fish, and of the same species 
that occur in the Lothian coal fields, viz. the Megalichthys and the 
Gyracanthus, occur in an impure limestone that forms the roof of the 
lowest workable coal, which limestone contains also terrestrial plants 
and bivalve shells, resembling the Sanguinolaria. Lower down in the 
series, and near what was probably the shore of the sea in which these 


_ strata were deposited, the shales and sandstones exhibit broken frag- 


ments of Coniferee and other plants having Serpule and Modiole at- 


tached to them. The workable beds of limestone are filled with all the 


marine shells usually characteristic of the carboniferous limestones. 
The superficial deposits consist. of bowlder clay which immediately 


covers the rocks, and is filled with blocks of grauwacke, basalt, and 
granite, clearly showing that it has come from the westward. This 
_ bowlder clay is covered by sand, which in some places is sixty feet deep 


and is continuous for many miles. Over this lies fine brick clay ; and 
above the sand is a covering of gravel. It would appear from this, 
that a sea had probably existed in the district, at the bottom of which 
the bowlder clay, by some violent cause, had been spread, that a long 
period of tranquillity thereafter prevailed, when at length the sea re- 
tired, whereby gravel was spread over its bottom, and the existing 


_ yalleys (which ave all east and west in direction) were scooped out. 


78 EIGHTH REPORT—1838. 


On the Red Sandstone, of the Tweed and Carlisle. By NicnoLas 
Woon, F.GLS. 


The author, referring to his memoir in the Transactions of the Natural 
History Society of Newcastle, described the inclined beds of red sand-. 
stone which rise out from under the mountain-limestone seriés on the 
sea coast, about a mile south of the Tweed. He stated his belief that 
these beds flatten towards the west, so as to form the great deposit of red 
sandstone of the Tweed, and supported this opinion by a section from — 
Berwick to the porphyritic hills of the Cheviot range near Barmouth. 
In the line of this section the relation of the red sandstone in ques- 
tion to subjacent coal-beds and overlying shales of the limestone series 
is clearly seen, and the flattening of the strata previously alluded to is 
witnessed at many points. The most conclusive evidence on this subject 
is obtained at the coal-workings on the south side of the Tweed. Near 
their junction with the porphyritic rocks south of Barmouth, the red 
sandstones assume inclined, vertical, or even reversed positions.—From 
all his inquiries Mr. Wood infers that the beds of red sandstone of the 
Tweed are referable to the series lying immediately below the moun- 
tain limestone and reposing upon the old red sandstone. 

The second part of the paper was illustrated by a section on the line 
of the north side of the ‘Great Dyke’ from the sea-side at Cullercoats 
‘near Newcastle to Croglin-fell in Cumberland, showing the position of 
the detached western coal-fields of Stublick, Hartley Burn, Midge- 
holme, &c. From Midgeholme the strata rise rapidly west, so that the 
limestone rocks come to the day, and one included coal seam is worked 
in Tindal-fell, and at Talkin, and crops out on the escarpment of Crog- 
lin-fell. Below this coal-bed appears a series of limestones, the ‘ whin 
sill,” a second layer of basalt, limestones and sandstones, and, in some 
of the deep ravines, beds of red sandstone lying underneath the lime- 
stones. 

The author compares with this mighty escarpment of the carboniferous 
limestone, thus based on red sandstone, the analogous and probably con- 
temporaneous section of Tweeddale, and further declares his conviction 
that the vale of the Eden as well as the vale of the Tweed rests on red 
sandstones, which rise from beneath the escarpments of limestone. In 
support of this opinion he states that the red sandstones of Cumber- 
land and the Tweed are very similar, and that they occupy precisely 
the same relative geographical position to the series of neighbouring 
mountain limestones. 

The coal of Sanquhar and Cannoby was noticed in connexion with 
this subject ; and regarding the latter, the author affirms it to be worked 
under limestones and red sandstones, and that extensive beds of red 
sandstone oyerlie this coal formation, and stretch from thence to the 
Solway Firth, while the coal strata are cut off on the north against the 
transition rocks. Mr. Wood entertains little doubt that the coal series 
of Dumfries-shire is to be placed on the same parallel as that of Ber- 
wickshire. 

The opinions thus advanced and supported were compared with the 


TRANSACTIONS OF THE SECTIONS. 79 


statements of other geologists, who have generally adopted with regard 
to one of the points discussed a different inference, as the sandstone of 
the Eden and the plain of Carlisle is by most writers ranked with new 
red sandstone. 


An Account of Rolled Stones found in the main Coal Seam of 
Cockfield Fell Colliery. By H.T.M.Wirnam, F.GS. 


Specimens of rolled stones, and a fragment of quartz, were exhibited 
and Mr. Witham stated them to have been found in the main coal seam 
of Cockfield-fell colliery, in a portion of which they are of frequent oc- 
eurrence. This portion is comprised in about 3 acres on the north side 
of the trap dyke, which does not seem to have influenced the position 
of the stones, as these are found in many instances at a distance of 400 
yards from it, and occasionally at greater distances. Similar specimens 
have been also met with on the south of the dyke as far as the outcrop 
of the coal. In the coal which is altered by the dyke for about 25 yards 
on each side, only one solitary specimen has been found, though they 
are abundant in the solid coal adjacent. A specimen has been also 
found at St. Helen’s Colliery, two miles to the north-east. 


On Sections of the Mountain Limestone Formation in Alston Moor, 
exhibiting the general uniformity of the several beds. By T. Sop- 
with, F.G.S. 


Mr. Sopwith stated that these sections form a portion of illustrations 
of the stratification across the island from the German Ocean at Sun- 
derland to the Irish Sea at Whitehaven, which could not be fully com- 
pleted in time for the present Meeting, but are now in progress for a 
subsequent meeting of the British Association. This series of sections 
will comprise the coal district of the county of Durham, by Mr. Bud- 
dle; the lead mine district, by Mr. Sopwith; the Cumbrian group of 
mountains, by Professor Sedgwick ; and the Whitehaven coal field, by 
Mr. Williamson Peile. The sections exhibited showed the succession 
and relative thickness of the several strata, and comprised comparative 
sections of the strata in the manor of Alston Moor, and of. the work- 
ings of several mines. 


On the Position of the Rocks along the South Boundary of the Penine 
Chain. By J. B. Juxes, F.GS. 


In this communication the calcareous strata of Derbyshire, which 
form the lower part of the whole Penine chain of mountains, are de- 
seribed at length; the superincumbent limestone shale and millstone 
grit are traced ; and the coal formation of Derbyshire is noticed both as 
to its mineral composition and relations to the new red sandstone series 


a 


80 EIGHTH REPORT—1838._ 


above. The memoir includes also a description of the Pottery coal- 
field, which fills a long trough from Biddulph to Lane End, on a syn- 
clinal axis from north to south. 

After a minute examination of many cases of disturbed stratification, 


the author states that, upon the most general view of the position of the. 


carboniferous system, in this district, it is perceived to be one great 
arched elevation on an axis from north to south, having also a gradual 
slope to the south. This great elevation is made up of many minor 
undulations, the higher parts of the middle of the arch being stripped 
off, and the inferior beds exposed to view. On every side, as soon as 
the beds descend to a sufficiently low level, they are masked from fur- 
ther observation by beds of the new red sandstone. 

Mr. Jukes describes minutely the proofs of the gradual attenuation 
of the magnesian limestone in its course to the South near Nottingham, 
till it dwindles to one yard in thickness, and is lost under the westward 
range of red and white sandstone which borders the Nottinghamshire 
and Derbyshire coal-field on its south side. 

Connected with this superposition of the red sandstones on coal, 
(themselves covered by the red and white clays which constitute the 
upper part of the red formation) is a point of great practical import- 
ance, viz. the extent to which coal may be reasonably looked for be- 
neath these red rocks. 

Among other evidence bearing on this question Mr. Jukes describes 
the narrow extensions and peculiar aspect of the red sandstone in the vi- 
cinity of Ashbourne ; notices the physical configuration of the country 
along the junction line of the red formation and the coal strata, which 
in places indicates a great depression of the latter, and the production 
of valleys in it anterior to the deposition of new red sandstone. He 
states, finally, that it is probable that a large part of South Derbyshire 
and the adjacent district is composed of the rocks belonging to the 
lower part of the carboniferous system, covered by the new red sand- 
stone; that the north point of the Leicestershire coal-field must be 
looked upon as the connecting link between the coal-fields of Derby- 
shire on the one hand, and of the north of Staffordshire on the other ; 
that the present break between them was caused in part by denuding 
forces acting before the new red sandstone period; and, consequently, 
that any mining operations in the south of Derbyshire in search of coal 
are unlikely to be attended with success. 


On the Silurian System of Strata. By R.1. Murcutsoy, 
F.RS., GS, §¢. 


Mr. Murchison exhibited to the Section the finished geological map, 
plates, and sections, prepared in illustration of his work on the Silurian 
System, and described the principles on which the map and the other 
illustrations were constructed and coloured. He also noticed the pro- 
bable extent of this system of strata in the British Islands, on the con- 
tinent of Europe, and other foreign localities. 


* ae Pi 
. . 


TRANSACTIONS OF THE SECTIONS. 81 


On the Geological Structure of the South of Ireland. 
By R. Grirritu, F.GLS. 


Mr. Griffith exhibited his new Geological Map of Ireland, which had 
been constructed at the Ordnance Survey Office, Dublin, by Lieute- 
nant Larcom, under the direction of Colonel Colby, of the Royal 
Engineers. 

Having briefly alluded to the geology of Ireland generally, and the 
principle which had been adopted in colouring the map, Mr. Griffith 
proceeded to illustrate the geological structure of the southern counties 
by the description of the sections, one of which commenced in the 
granite district of Mount Leinster in the county of Carlow, and ex- 
tended in a line nearly parallel to the south-east coast through the 
counties of Kilkenny, Waterford, and Cork, crossing the valley of the 
river Suir, at Carrick-on-Suir, passing over the summit of the Mona- 
vullagh mountains in the county of Waterford, crossing the valleys of 
the river Blackwater at Lismore, the Bride at Tallow, and the Lee at 
Cork Harbour, and terminated at Cork Head on the south coast of 
the county of Cork. 

The second section extended from Brandon Head in the county of 
Kerry in a south-eastern direction, crossing the summits of Cahirconree 
and Carrawntoohil mountains, the valleys of Kenmare and Bantry, and 
terminated at Gally Head, also on the south coast of the county of 
Cork. 

_ According to Mr. Griffith’s views, the structure of the south-east of 
Ireland, commencing at Mount Leinster in the county of Carlow, and 
following the order of superposition, consists of a base of granite, on 
which rest strata of a rock intermediate between mica slate and clay 
slate. To the south and west of Killeen Hill, clay slate extends to the 
base of the conglomerate ridge of the county of Kilkenny, where at 
Coolnahay Hill, in the line of section, beds of coarse-grained red con- 
glomerate, composed of rounded fragments of quartz, cemented by a 
brown or reddish brown arenaceous paste, are observed to rest wncon- 
formably on the clay slate, which dips to the south at an angle of about 
60° from the horizon, while the conglomerate beds dip nearly to the 
same point at an angle of about 20° from the horizon. These conglo- 
merate beds are identical-in position and composition with those which 
underlie the carboniferous limestone to the north of Hook Head, and 
in other parts of the county of Wexford, which are universally admitted 
to belong to the old red sandstone series, and, like those of Coolnahay 


Hill, rest unconformably on old clay slate. 


The thickness of the conglomerate at Coolnahay may be about 300 

feet. It is succeeded by beds of coarse-grained quartzose slate, and 
occasionally of red quartz rock. 
_ The same succession may be tracec as far as the river Suir, where 
the red beds are succeeded in a contormable position by strata of yel- 
lowish white arenaceous quartz rock, and these again by beds of greenish 
gray imperfect clay slate, which latter: rock alternates with the lower 
beds of the carboniferous limestone of the valley of the river Suir, 

VOL, VII. 1838, G 


82 EIGHTH REPORT—1838. 4 


In this valley the strata of the carboniferous limestone form a syn- 
clinal depression, the beds to the north of the river dipping south, and 
those lying south of it dipping to the north. 

On the-south side of the Suir, the strata which have already been 
described are observed resting in the same order of succession on the. 
extensive clay-slate district of the county of Waterford, in which are 
situated the important slate quarries of Glenpatrick and other localities. 

Proceeding to the southward from the clay-slate district of Water- 
ford, the line of section crosses the summit of the Monavullagh moun- 
tains, which consist of a vast accumulation of conglomerate similar to 
that already described, and forming an escarpment nearly perpen- 
dicular for an elevation of about 500 feet; the strata dip to the south 
at an angle of 10° from the horizon. As in the cases mentioned be- 
fore, this conglomerate is succeeded by coarse red slate and quartz 
rock, but in descending towards the river Blackwater, near to Lismore, 
we find beds of roofing slate interstratified with the quartz rock, and it 
is to be observed generally, that the roofing slate occurs only in the 
upper portion of the red slate series. 

Approaching the Blackwater, the clay slate is succeeded in a con- 
formable position by yellowish white sandstone and sandstone slate, 
which in many localities is found to contain casts of Calamites, and 
apparently of some varieties of Stigmaria, and these again, as in the 
valley of the river Suir, by the greenish gray imperfect clay slate, 
which alternates with the limestone of the valley of the river Black- 
water. This valley, like that of the Suir, is connected with the ad- 
mitted carboniferous limestone district of the counties of Cork, Tippé- 
rary, &c. 

The whole of the limestone beds of the river Blackwater at Lismore, 
dip to the south, but not at equal angles from the horizon; on the 
north side of the valley the angle of inclination does not exceed 20°, 
while in the middle and southern side it amounts to 80° or 85°, but 
still the inclination is to the south. 

Proceeding to the southward beyond the limestone boundary, we 
find greenish gray clay slate and yellowish sandstone similar to those 
already described on the north side, inclining to the south at an angle 
of about 85° from the horizon. Judging from the position of the strata 
alone, these schistose and arenaceous beds might be supposed to be 
superior, instead of inferior to the limestone. But arguing from the 
analogy afforded by other localities in the south of Ireland, there can 
be no hesitation in admitting that the strata are here contorted. 

Contortions are frequently observable on the sea coast and in many 
precipices and quarries in the interior of the country, and although, 
when seen at the surface, the strata everywhere dip towards the south, 
still these strata present a series of convolutions, frequently on a small 
scale, both sides of which incline to the southward, though usually at 
different angles. This peculiarity is general throughout the southern 
counties, and is alike observable in the transition slate, the limestone 
series and the culmiferous strata,—a circumstance which shows the 
necessity of extreme caution in making calculations as to the probable 


TRANSACTIONS OF THE SECTIONS. 83 


thickness of any formation, founded solely on the persistence of the 
dip of the strata towards any particular point. 

To the south of Lismore a low ridge intervenes between the valleys 
of the river Blackwater and the river Bride at Tallow. This ridge is 
composed of coarse red slate, and occasionally rather fine-grained 
greenish gray clay slate. The strata for the most part dip to the 
south, but in the centre of the ridge they form an anticlinal axis. 
Approaching the valley of the Bride at Tallow, we again meet with 
yellowish white sandstone beds containing Calamites similar to those of 
the valley of the Blackwater, and also greenish gray imperfect slate, 
which, as before, is succeeded by the limestone; here the calcareous 
strata form a regular trough, those on the north side dipping to the 
south, and on the south side to the north, beyond which we have the 
usual succession of strata which are interposed between the red schistose 
beds and the limestone. 

Proceeding to the southward, the section crosses the barony of 
Barrymore in the county of Cork, which forms the base of the lime- 
stone trough of the valley of Middleton and Youghal, and thence con- 
tinues to its southern termination at Cork Head. Within this space 
a succession of strata similar to that already described, is repeated 
three times; first we have the red quartzose slate ridge of the barony 
of Barrymore, succeeded by the limestone trough of the valley of Mid- 
dleton and Youghal; next the low red quartzose ridge of Great Island 
in the harbour of Cork, succeeded by the limestone of that harbour, 
Carrigaline, &c.; and lastly, the red quartzose ridge of Hoddersfield, 
which is succeeded on the south side by the blackish gray carboni- 
ferous slate which forms so characteristic a feature along the south 
coast of the county of Cork. This blackish gray slate appears to be 
similar to the greenish gray slate of the valleys of the Suir, the Black- 
water, and the Bride; it underlies the limestone of the valleys of Mid- 
dleton and of Cork Harbour, where it contains small Orthocerata in great 
abundance, and in some localities it contains Calamites. Approaching 
the limestone of Cork Harbour at Rosslillan, Renniskeddy, &c. the 
slate assumes a gray colour, is interstratified with limestone, and con- 
tains numerous fossils belonging to the carboniferous series, identical 
with those which occur in a similar position at Killinamack, in the 
- county of Waterford, close to Knocklotty Bridge, over the river Suir. 
On the evidence of the sections thus briefly described, Mr. Griffith 
grounds his conclusion, that the limestones of the valley of the Bride, 
Cork Harbour, &c. belong to the same geological series as those of the 
Blackwater and the Suir, which are connected with the great car- 
boniferous limestone field of Ireland, and this inference from the ob- 
served position of the rocks is stated to be confirmed by the evidence 
at present collected from organic remains, 

In respect to the section of the strata near the western coast of the 
counties of Kerry and Cork, already mentioned, which was also exhi- 
bited by Mr. Griffith, similar proofs respecting the order of super- 
position of the strata were brought forward to show that the limestone 
of Killarney, Kenmare, and Bantry belongs to the carboniferous, and 

G2 


84 EIGHTH REPORT—1838., i 


not to the transition series ; and also that the red conglomerate beds 
of Cahirconree, and Carrantoohill mountains, together with the coarse 
red slate of which Tornies and Glena mountains at Killarney are com- 
posed, belong to the old red sandstone series. 


It is to be observed, that the schistose strata belonging to the se-. 


condary formations of the south of Ireland are much more compact than 
those of the northern districts, and hence we find the quartzy slates 
and sandstones of the old red sandstone series have assumed the form 
of coarse clay slates and quartzy rocks ; and also the dark gray car- 
boniferous slates of the south of the county of Cork, which contain 
Orthocerata, Calamites, &c., have assumed the character and fissile struc- 
ture of ordinary roofing clay slate; and several extensive slate quarries 
have been opened in different parts of the district, but these slates are 
not found to be of a durable nature. 


On a small Tract of Silurian Rocks in the County of Tyrone. By 
Captain Porttiock, F.G.S. 


Captain Portlock remarked that he first recorded the existence in 
the County of Tyrone of rocks of the Silurian system, in the 1st volume 
of the Ordnance Survey Memoir of the County of Derry, and that he 
considers this to be the first authenticated case of their occurrence in 
Ireland, though there is little doubt that they also exist in Kerry and 
other counties. The tract in question is small, extending only over a 
few miles of surface in the eastern portion of Tyrone; it rests upon 
granitic and other primary crystalline rocks, and is succeeded by rocks 
partly belonging to the old red sandstone, and partly to the carbonife- 
rous system, by which it is completely detached from other rocks of a 
similar epoch. Apparently it has been raised up from its original level 
by the intrusion or eruption of the granitic mass, a movement which 
must have occurred prior to the deposition of the more recent rocks, as 
they exhibit no appearance of disturbance. The portion of the Silu- 
rian system, here exhibited, appears capable of sub-division. The lower 
or gritty slate is manifestly a fragmentary rock, and remarkable for 
containing great numbers of a brachiopodous bivalve, which is either 
identical with, or very similar to, Orthis grandis of Murchison. Above 
this is a black, smooth schist, occasionally slightly caleareous, and some- 
times thinly laminated by calcareous spar. This is the depository of the 
Graptolites (Zomatoceras, Bronn), which are abundant. 

The upper part of the Silurian district is a more decided slate, and 
abounds in Trilobites of the genera, Calymene, Asaphus, Cryptolithus, 
(Green,) Trinucleus, (Llwyd and Murchison). Jilenus? perovalis, 
Murchison, and what Captain Portlock is inclined to believe the true 
Isotelus, besides some species of doubtful genera. This district will be 
fully illustrated in one of the earliest forthcoming parts of the Ordnance 
Memoir, and these and other fossils, such as Orthocerata, Bellerophon, 
Lingula, ete. figured. 


tae) 
, 
- 
, 


An Account of the Footsteps of the Cheirotherium and five or siz smaller 
Animals in the Stone Quarries of Storeton Hill, near Liverpool, 
communicated by the Natural History Society of Liverpool, through 
Dr. Buckland. 


These footsteps were first noticed, in June last, by Mr. Cunningham 
and Mr. Tomkinson, who have taken means to preserve specimens in 
the Museum of the Natural History Society of Liverpool. Dr. Buck- 
land haying visited the quarries last week, confirmed the accuracy of 
the statements contained in the present communication. He found 
nearly all the circamstances identical with those attending the footsteps 
of similar animals discovered at Hildberghausen in Saxony, three years 
ago, in a bed of white stone belonging to the new red sandstone forma- 
tion. The most remarkable of these footsteps are those of the hind-feet 
of the Cheirotherium, which nearly resemble the form of a large man’s 
hand ; the fore-feet of this animal have made much smaller impres- 
sions: other footsteps of four or five smaller animals are found on the 
same slabs with those of the Cheirotherium; they are apparently the 
tracks of small aquatic and land tortoises. (A further account has 
been communicated to the Geological Society since the meeting at 
Newcastle.—See Geological Proceedings, vol. iii, No. 59.) 


TRANSACTIONS OF THE SECTIONS. 85 


Dr. Buckland exhibited and explained enlarged sections copied from 
Cotta’s recently published sections, showing granite and syenite over- 
lying strata of the chalk formation at Hohnstein, Oberau, and Wein- 
bohla in Saxony ; and laid on the table Mr. Cotta’s Memoir in which 
they are described. 


On a Plan of Cementing together Small Coal and Coal Dust for Fuel. 
By Mr. Oram. 


Dr. Buckland stated the object of this plan to be the rendering these 
substances available for economical purposes, by moulding them into 
the form of bricks; and stated the results of trials made by Mr. Oram, 
at Woolwich, to test the efficiency of this substance, when it appeared 
that in working a 10-horse pumping engine, 750lbs. of this prepared 
fuel were equivalent to 1128lbs. of Wylam Main coal. 

1046lbs. of large Welsh coal. 
988lbs. of Pontop coal. 
and to 680lbs. of a compound of the small coal, an- 
thracite, and coke. These experiments were made under the inspec- 
tion of P. Ewart, Esq. 


Description of a Cave at Cheddar, Somersetshire, in which Human as 
well as Animal Bones have been lately found. By Mr. Lone. 


After noticing the circumstances which led to the discovery of the 
bones, the author describes the cave. 


86 EIGHTH REPORT—1838. _ 


The cave is situated on the summit of the range of the Mendip, in 
limestone rock, and the entrance to it is from the flat surface, not from 
any broken chasm in the declivity of the rocks. This is generally the 
case with the other bone caves hitherto discovered in these hills, all of 
which are in the like strata of rock. The fissure of rock by which the » 
cave was entered is about thirty feet in depth, a perpendicular descent ; 
thence bearing to the west, is the opening which leads into the cave; 
from general appearances, and from what was afterwards discovered, 
this does not appear to have been the original entrance to the cave, 
and most likely was made for the purpose of admitting light and air. 
On entering the cave from this opening, the visitor finds himself in a 
lofty but not very large chamber, about sixty or seventy feet in height ; 
from this cave there is an arched way into another smaller chamber, 
and from thence an ascending path leads towards the plain surface of 
the rock; this passage was undoubtedly the original entrance. 

The bones were found in a detritus of soft mud or diluvium, as is the 
case in all the other ossiferous caves of this district, and so circum- 
stanced as to be defended from the pressure of soil above, and excluded 
from the air. The human bones were found beneath the animal bones, 
so far as the cave has hitherto been searched; a few remains of foxes 
and sheep were found at the head of the cave, but the bones to which 
attention was particularly drawn, were found in a mass, in quite a sepa- 
rate position, and easily distinguished from those of a more recent date. 
“In searching in the cave,” says Mr. Long, “I found some bones im- 
bedded in stalactite, as also one almost forming part (as it might be 
termed) of a rocky substance. It was the work of many hours to 
clear away the soil and rock to obtain any specimens of the bones, but 
I was successful in finding both human and animal bones, having been 
accompanied by the individual who had been most active in the former 
search. In the first instance there were about nine human sculls found 
together, with a large quantity of human bones, and with them were 
the bones of bear, deer, ox, and horse. By comparison with the bones 
in Mr. Beard’s extraordinary collection at Banwell, they are exactly 
similar and apparently of the same era. Some of the bones and sculls 
fell to pieces and crumbled to dust on being exposed to the air.” 


On the Discovery of the Northern or Diluvial Drift containing Frag- 
ments of Marine Shells covering the remains of Terrestrial Mam- 
malia in Cefn Cave. By Josuua Trimmer, £.G.S. 


Mr. Trimmer’s attention being drawn to the investigation of diluvial 
phenomena in North Wales by the discovery of marine shells of exist- 
ing species near the summit of Mael Tryfan in Caernarvonshire, which 
is 1392 feet above the sea, he has become impressed with a growing 
conviction that the detrital deposits of North Wales were suddenly 
spread over pre-existing land, and not gradually accumulated beneath 
the sea. The evidence on this subject he has presented to the Geolo- 
gical Society, Dublin. In the present communication he deseribes the 


TRANSACTIONS OF THE SECTIONS. 87 


occurrence of marine remains covering the bones of land animals in 
Cefn Cave, in Denbighshire, on which he has also presented a memoir 
to the same society. 

The principal deposit of bones lies dedow the level of the entrance, 
and beneath one if not more than one crust of stalagmite. The bones 
in this lower deposit are accompanied by rounded pebbles of grauwacke, 
slate, and limestone. The surface of the wpper mass of marl, with an- 
gular pieces of limestone and bones, is covered by a deposit of sand, 
divided by a few inches of finely laminated marl, and in this sand, the 
total thickness of which, including the marl, does not exceed 18 inches, 
are fragments of marine shells. These fragments are small and not 
very numerous, but they are not smaller than a considerable portion of 
the fragments dispersed through the northern drift which covers the 
surface of the neighbouring country. At the extremity of the exca- 
vations in the cave, this sand is covered by a thin film of stalagmite. 
No marine remains were found in any other part of the cave, nor were 
any perforations of lithodomous shells seen on the sides. ; 


On the Shells of the Newer Pleiocene Deposits. By JAMES SMITH, 
F..G.S., of Jordan Hill. 


The author communicated the result of a comparison made by him 
between the marine shells found in elevated stratified deposits belong- 
ing to the newer pleiocene tertiary formation of the British Islands, 
with those now existing in the adjoining seas. Out of 176 species, 92 
per cent. were recent, and 8 per cent. extinct or unknown. 


On Vertical Lines of Flint, traversing Horizontal Strata of Chalk, 
near Norwich, By C. Lyex1, P.RS., GS. 


It has long been known that near Norwich the horizontal beds of 
flint nodules in the white chalk are crossed by perpendicular rows 
of much larger flints, often several yards in height. ‘These larger and 
vertical flints are provincially called potstones, and are the same as 
those which occur in the chalk of Ireland, and are described by Dr. 
Buckland under the name of paramoudra. Ata place called the Grove’s 
End House, near Horsted, about six miles from Norwich, an excava- 
tion has been made, from 15 to 20 yards wide, and nearly half a mile 
in length, through 26 feet of white chalk, covered by strata of sand, 
loam, and shelly gravel, about 20 feet thick. In the chalk thus in- 
tersected, the rows of potstones are remarkable for their number and 
continuity ; it is affirmed by those who for more than twenty years 
haye superintended the cutting of the canal, that every row of upright 
flints has been found to extend from the top to the bottom of the 
chalk, so far as the excavation has been carried downwards. The 
rows occur at irregular distances from each other, usually from 20 to 


88 EIGHTH REPORT—1838. | 


30 feet apart, and they are not portions of continuous siliceous beds 
in a vertical position, but piles of single flints running through the 
chalk, like so many wooden stakes driven into mud. Few of the sepa- 
rate flints are symmetrical, but some are pear-shaped. They are very 
unequal in size—usually from a foot to three feet in their longest dia- 
meter. At the point of intersection between a row of potstones and 
one of the horizontal beds of flints, there is no mutual interruption 
or shifting, but they are united as if both were formed at one time. 
Each potstone is not siliceous throughout, like the nodules of flint in 
the horizontal beds, but contains invariably within it a cylindrical 
nucleus of chalk, which, when deprived of its siliceous envelope, has 
the form and smooth surface of a tree when stripped of its bark. This 
internal mass of chalk is much harder than the ordinary chalk sur- 
rounding the flints, and does not fall to pieces when exposed to frost: 
it penetrates the flinty covering at the top and bottom of each potstone. 
A ventriculite was observed in the chalky nucleus in one instance. 
The author concluded by inviting those geologists who resided near 
Norwich to examine these phenomena more minutely ; and adverting 
to the late discoveries of Ehrenberg, declared his expectation that the 
origin both of the vertical and horizontal masses of fiint would be 
found to be intimately connected with the fossil remains of Infusoria, 
sponges, and other organic beings. 


On the Stratification of Rocks. By Joun LEITHART. 


The strata in Alston Moor, to which Mr. Leithart’s personal obser- 
vations have been chiefly confined, consist of numerous alternations of 
limestone, argillaceous shale or ‘plate,’ and sandstone. The definite 
order in which these rocks succeed one another, the variety of inclina- 
tions which they present, the phenomena of faults which interrupt the 
continuity of the strata, and other facts, appeared to the author inex- 
plicable as the result of deposition from water, followed by elevatory 
action or the influence of heat. 

Being engaged in the study of galvanism, he remarked that many 
other substances besides metals would, when piled in alternate layers, 
develop electrical action, and became impressed with the opinion that 
the stratified rocks might be likened to a galvanic battery, and that the 
peculiar appearances above noticed might receive an explanation upon 
this supposition, provided there was a communication across the enor- 
mous ‘pile’ of rock: such a communication is made, the author thinks, 
by mineral veins. 

Upon this hypothesis he proceeds to show the probability that mixed 
sediments would be re-arranged by the electrical action into alternating 
distinct zones or strata, and confirms his reasoning by the result of 
direct experiments. In the first of these, a battery of 28 cylindrical 
plates of copper and zine was used, but the author finds 18 or 20 pairs 
answer better. The copper plates had about 9 and the zine plates 
about 6 square inches of surface. They were placed in jars, containing 


TRANSACTIONS OF THE SECTIONS. 89 


a mixture of 59 parts water and 1 part muriaticacid. The substances 
submitted to experiment were limestone and sandstone, mixed and re- 
duced to fine powder and made into a paste with water. This mixture 
was put in a glass tube half an inch in diameter; the ends of the tubes 
were closed by metallic discs united to the connecting wires of the 
battery ; and thus the mixed sediment was interposed in the line of 
the electrical currents. The result was a decided appearance of stra- 
tification, and a strong cementation of the mass. 

In all the subsequent experiments the author endeavoured to imitate 
nature by a more slow electrical action, and employed only spring water 
as an exciting fluid. 

In a mixture of limestone and shale the former was invariably re- 
arranged on the zinc or negative end of the battery, and the shale on 


. the other. Ina mixture of limestone, sandstone, and shale, the same 


result occurred, the sandstone grains remaining in the middle, and 
being of the three the most consolidated. By adding to the small battery 
by which limestone and shale had been stratified the influence of 
another of equal force, the stratification became waved; by adding a 
greater electrical force, the materials collected at the upper end were 
seen to be displaced and carried irregularly through the other parts of 
the mass in thin veniform portions. The author considers these ex- 
periments strongly confirmatory of his hypothesis. 

Several tubes filled with the substances named, and answering in the 
arrangement of them to the description given by Mr. Leithart, were 
exhibited to the geological section, and the author was prepared to re- 
peat his experiments for the satisfaction of the members. He remarks 
that dises of tin and silver answer best for closing the glass tubes. 


On Faults, and Anticlinal and Synclinal Axes. By J oHN LEITHART. 


It is the opinion of the author, that these remarkable interruptions 
to the symmetrical arrangement of the earth’s strata are not to be ex- 
plained as the consequence of real changes in level of the surface of 


' the earth, but as the result of electro-dynamic agency in the interior, 


operating through the mass of the rocks. The truth of this opinion 
he attempts to demonstrate by comparing the real phenomena of faults 
and axes of displacement of the strata, with the effects of electrical 
action predicted upon the following suppositions :— 
1.—That electrical currents circulate in the earth; 
2.—That faults, veins, &c. are the chief channels by which the elec- 
trical equilibrium between the surface and interior of the earth 
is maintained ; 
3.—That the stratification of the rocks forming the earth’s crust is 
the result of the electro-polar action of these currents ; 
4.—That each stratum possesses its own peculiar electric condition 
and. currents. 


90 EIGHTH REPORT—1838._ 


On the Production of a Horizontal Vein of Carbonate of Zine by 
means of Voltaic Agency. By Ropert Were Fox. 


In this experiment a quantity of finely pulverised slate was mixed-up 
in an earthenware vessel with a strong solution of common salt, and 
allowed to subside and form a bed, resting on a plate of zine, which 
had been previously placed at the bottom of the vessel. A plate of 
copper, connected by a wire of the same metal with the zinc, was then 
placed horizontally on the bed, which was about 14 inch in thickness ; 
the whole being covered by salt water. On taking out the contents of 
the vessel, several months afterwards, a well-defined vein of carbonate 
of zine, about =4th of an inch thick, was found in the bed, in nearly a 
horizontal position. This vein occurred rather nearer to the copper 
than the zine plate, and extended over several inches of surface. It 
was sufficiently hard to admit of its being taken out of the bed in 
plates, and many parts of it would scratch glass, in consequence of mi- 
nute portions of quartz having been inclosed therein. The carbonic 
acid was doubtless derived from the atmosphere, and the flat or hori- 
zontal position of the vein may be ascribed to the perpendicular direc- 
tion of the voltaic action ; because, in other experiments, in which si- 
milarly moistened clay was placed between vertical plates of copper and 
zine, similar veins were formed in a perpendicular direction. The veins 
were of different kinds when different metallic solutions were employed, 
and the effect was generally most satisfactory when a constant battery 
of several pairs was used. 

In many instances, when copper was present in the solution, the car- 
bonates of zinc and copper were found in the mass of clay, occurring 
together in the same vein, not mixed, but in parallel plates, side by side, 
the copper being on the side of the vein nearest the zine plate, and the 
zine on the side nearest the copper plate. ‘This definite arrangement is 
too constant to be referred to any other cause than voltaic agency, and 
its resemblance to some of the phenomena of mineral veins is very 
striking. The most marked of these results have been obtained by 
T. Jordan, of Falmouth, by the long-continued action of a constant 
battery of several pairs of cylinders on clay moistened by a solution of 
sulphate of copper. 


On the Structure of the Fossil Teeth of the Sauroid Fishes. 
By Sir D. Brewster, K.H. 


The fossil teeth to which this notice refers were found imbedded in 
coal from Inverkeithing, in the county of Fife. They were deeply 
fluted at the base, but had no hollow cone within, like those figured by 
Dr. Buckland, in his Bridgewater Treatise, and discovered by Dr. 
Hibbert in the limestone of Burdie-house. 

Tn all the teeth which Sir D. Brewster has examined, the interior was 
filled up with a yellowish brown mineralized substance, having in the 
centre of the section or the axis of the tooth a white substance of the 


- 


same character. The surface of fracture was partially covered with a 
number of small and exceedingly thin scales, almost perfectly transpa- 
rent. They adhered to the brown matter with such tenacity that it was 
difficult to detach them for the purpose of examination by the micro- 
scope. Within the fluted base of one of the teeth, the white and brown 
substances are united together very irregularly, and in some places are 
combined with a third substance of a coaly nature, which burns without 
flame or smell, upon a heated iron. The enamel is in many places 
finely preserved. It has a yellowish transparency, and exhibits a sort 
of ramified structure both by reflected and transmitted’ light, the re- 
flected tints having in some places a sort of nacreous lustre. 

During the examination of the brown substance by which the cavity 
of the tooth is filled, the author noticed something like a veined struc- 
ture ; and upon a narrower inspection succeeded in tracing a regular 
Structure in every part of it, exactly similar to that of a nodule of 
agate. The brown substance, which consists of bituminous and calca- 
reous matter, seems to have been deposited and indurated in successive 
layers concentric with one mould of enamel, by which they were in- 
closed. The annexed sketch, on a magnified scale, will convey some 
idea of this structure, which Sir D. Brewster found more or less di- 
stinctly developed in every tooth. Upon subsequently examining the 
fossil teeth of Burdie-house, deposited by Dr. Hibbert in the Museum 
of the Royal Society of Edinburgh, the author perceived distinct traces 


of the same structure in one or two which presented fractures capable 
of displaying it. 


TRANSACTIONS OF THE SECTIONS. 91 


On the Geology and Thermal Springs of North America. By Dr. 
Davseny, Professor of Chemistry and Botany, Oxford. 


In this communication the author gave a rapid sketch of the mineral 
structure and direction of the mountain chains in North America, with 
a view of explaining the position which the thermal springs in the 
Same country occupy, with reference to the adjacent rocks. 

He then proceeded to describe the thermal springs themselves 
ons he had visited in the course of his visit to the western hemi- 

phere. 4 


ist. In the mountain region of Virginia, west of the Blue Ridge, 


92 EIGHTH REPORT—1838. 


occur two groups of thermal waters: the first, called the Warm 
Spring, possessing a temperature of 96° Fahr.; the second, the Hot 
Spring, having one of 102°. Both emitted copious bubbles of air, 
which by analysis were found to consist as follows :— 


Caen Nitrogen.| Oxygen. 


: Ladies’ Bath ...| 11 98 2 
Peon ine ey SEE { Gentleman's Bath 8 96 4 
From the-HotSpring®. -¢ 2.22 )) 0.2" ok 6 94: 6 


Both these groups lie at a distance one from the other of about 3 
miles, in a valley running nearly N. and S., which occurs exactly at the 
part at which Professor Rogers, of Virginia, has placed the anticlinal 
axis of this part of the Alleghany chain. The same series of rocks is 
in fact repeated immediately to the east and west of the Springs, and 
assumes a nearly vertical position in both cases. 

2nd. In the state of New York, at Lebanon, west of Albany, is a 
thermal spring, possessing the temperature of 73°, and emitting bub- 
bles of gas which consisted of nitrogen 89°4, oxygen 10°6, without a 
trace of carbonic acid. It occurs near the junction of talcose slate 
with highly inclined beds of limestone, belonging to the Transition or 
Silurian system, and there are traces of a fault near it. 

The carbonated springs of Ballston and Saratoga are not in general 
regarded as thermal, but the temperature of one of those of Ballston 
was found to be 50°5, of the other 49°5; whilst at Saratoga, the New 
Congress Spring and Hamilton Spring both had a temperature of 494, 
and Congress Spring one of 51°. Now the mean temperature of Sche- 
nectady, the nearest point to these springs at which a meteorological 
register has been kept, is stated to be only 46°20. The gas given out 
by both these groups of springs was of the same quality, consisting 
chiefly of carbonic acid, but containing also a small residuary portion 
of air, in which nitrogen existed in larger quantity than in the atmo- 
sphere. 

a In the state of Arkansas, near the river Wachita, between the 
34th and 35th parallels of latitude, and 16 degrees of longitude west of 
Washington, occurs a group of thermal springs, varying in temperature 
from 148° to 118° of Fahr., and emitting bubbles of gas which were 
found to consist of carbonic acid 4, nitrogen 92°4, oxygen 7-6. They 
gush out from the junction of clay slate with quartz rock, both belong- 
ing to the primary chain of the Ozark mountains. 

The professor concluded by pointing out the correspondence between 
the phenomena of these springs, both as regards the composition of the 
gases emitted, and their position amongst rocks that had been sub- 
jected to violent action in their immediate neighbourhood, with those 
which he had deduced in his report on mineral waters, published in the 
Transactions of the British Association for 1836, from a survey of the 
mineral waters existing in various parts of Europe. 


TRANSACTIONS OF THE SECTIONS. 93 


Considerations on Geological Evidence and Inferences. By R. C. 
Austen, F.G.S. 


The object of this communication was to examine the soundness and 
applicability of certain geological inferences, regarding the ancient 
land and sea, which have been freely adopted, sometimes in a general 
sense, upon local and limited data, insufficiently compared (the author 
thinks) with the laws of existing nature. The subjects discussed were 
the geographical areas over which particular mineral characters extend, 
and the degree in which the conformity of such characters is to be 
esteemed evidence of contemporaneous deposition; the succession of 
organic life in the ancient land and sea, and the contemporaneity of 
identical species in unconnected deposits and distant quarters of the 
globe ; and ancient climate. The investigation does not admit of con- 
densation, but the following are among the author's conclusions : — 
1.—The identification of strata by zoological characters can never 
be done, except over very limited areas ; a few degrees of lati- 
tude must always have brought about a perfect change. 

2.—Along the same line longitudinally analogy does not allow us to 
expect a much wider range of the same animal or vegetable 
forms. 
3.—Organic remains offer no proof whatever that the distant depo- 
sits are contemporaneous, but rather are proofs to the contrary ; 
viz. that contemporaneous deposits, in situations removed from 
each other, can never have had zoological characters in common. 

4.—Mineralogical character is only evidence as to a certain condition 
of water, under which the deposit was formed. Nor is inclined 
stratification a necessary consequence of disturbance, as some 
of the beds of recent stratified sandstone in Devon and Corn- 
wall have been deposited at high angles. 


On Lunar Volcanos. By T. W.Wezs. 


The author, after showing the inadequacy of some of the grounds 
upon which the activity of lunar volcanos is often maintained, states 
the result of particular observations which appear to him to support 
the conclusion. 

“Tt is obvious,” he observes, “that either the formation of new craters, 
or the enlargement of those previously existing, would afford convincing 
proof of the continuance of explosive or eruptive action: and having 
examined several portions of the moon with an excellent achromatic 
telescope of five-feet by Tully, with the express view of detecting any 
appearances of the kind, I think I am enabled to assert that both the 
one and the other of these changes have taken place since the observa- 
tions of Schroter at the close of the last century.” 

The general result is, that craters apparently of recent origin, and 
not to be found in Schréter’s plates, are now equally conspicuous with 


« 


94 * EIGHTH REPORT—1838, 

those which he has delineated, and in situations where it is hardly con- 
ceivable that he could have overlooked them; and that in other places 
those which he has represented now exhibit a difference in magnitude 
which cannot well be explained by any supposition of accidental haste 
or inaccuracy. The charts of Lohrmann unfortunately do not contain 
those portions of the lunar surface in which Mr. Webb conceives these 
alterations to have taken place; but he had the pleasure of finding 
several of his observations confirmed by the beautiful Mappa Seleno- 
graphica of Messrs. Beer and Madler ; and he expresses a hope that a 
more extended and accurate investigation may, in the course of a few 
years, not only bring to light the progress of many interesting changes, 
but may even enable us to form some inferences as to the nature and 
mode of action of that power which has produced such extensive and 
multiplied revolutions upon the lunar surface. 


—— 


On the Construction of Geological Models. By Tuomas Sorwitu, 
F.GS 


Next to the actual inspection of any object, a model is the most per- 
fect means of conveying a clear idea of the general appearance and 
construction of the object which it represents; and in some cases a 
model exhibits and explains details which either cannot be grasped at 
once by the eye in the real object, or which are hidden from actual in- 
spection, as in the case of the geological structure of the earth, or the 
interior of mines. 

Some difficulty, however, has been found in conveying to ordinary 
workmen such a knowledge of geological or mining details, as shall 
enable them to execute a work of so much intricacy as these subjects 
usually present. The following method was pursued in the construc- 
tion of a model of Dean Forest, and it is equally applicable to any geo- 
logical model of a district. 

Being in possession of an accurate plan and sections of the district, 
derived from surveys which he had made for the Commissioners of 
Woods and Forests in 1834, Mr. Sopwith divided the tract of country, 
comprehending about thirty-six square miles, by two series of parallel 
lines intersecting each other at the distance of a mile from each other, 
A vertical section was then prepared, corresponding with each of these 
lines. These several sections were drawn upon thin pieces of wood, 
which were united together by being what workmen term half lapped, 
forming a skeleton model of vertical sections. After having been united, 
the sections were taken separately, and cut into portions corresponding 
with the contour of the several layers of strata to be represented, the 
corresponding points of intersection having been previously marked 
with figures. These respective portions are again united, to form the 
exterior boundary or vertical edge of a square mile of rocks. The in- 
terior of each of these squares is filled with wood, and carved so as to 


. 


TRANSACTIONS OF THE SECTIONS. ~ 95 


coincide with its boundary edges. Any intermediate portion of the 
square may be ascertained by inserting a slip of wood cut to any known 
section ; and in this manner the dislocations of strata, or any other phe- 
nomena, may be at once delineated, so as to enable the workmen to 
execute it in the model. By this means a connexion is at once esta- 
blished between the scientific drawings of the geologist and the opera- 
tions of a common workman. 

The contour of the surface is obtained partly by the upper edge of 
the section or slips of wood already described, and partly by the use of 
a gauge or graduated pencil sliding in a frame, and acting in the same 
manner as the gauge used by sculptors in transferring dimensions from 
a east to a block of marble. 

This method of constructing geological models was illustrated by 
several examples. 


On the Structure of the Teeth. By Professor OwEn. (See Medical 
Science.) 


On the Antiquity of Organic Remains. By the Rev.G. Youne, D.D. 


In this communication Mr. Young opposed the inferences generally 
admitted among geologists, as to the high antiquity of the stratified 
rocks, and the successive eras of existence of the organic remains of ~ 
plants and animals imbedded in them. He endeavoured to show that 
the production of the phenomena observed was possible in less time, 
and with fewer changes in the condition of the globe, than modern 
writers commonly admit. 


—_—_— —_—_— 


On Peat Bogs. By G. H. Apams, M.D, 


From a microscopic observation of the substance of fresh and old 
peat, the author described the gradual growth of the~vegetable mass, 
and its conversion into condensed peat. To render peat bogs fit for 
agricultural purposes, the author proposes to take off the upper part, 
and to burn it in large smouldering heaps, using the ashes as manure 
for the subjacent peat surface. He also notices the practice of sprin- 
kling diluted sulphuric acid over and through heaps of the surface-cut 
peat, thus ‘souring’ the peat and rendering it of considerable value as 
manure. 


96 EIGHTH REPORT—1838. 


4 


GEOGRAPHY. 


Recent Intelligence on the Frozen Soil of Siberia. By Professor Von 
Barr, of St. Petersburgh. Communicated by W. R. HAMILTON, 
Esq. President of the Royal Geographical Society of London. 


It may be remembered that M. Baer has on a former occasion de- 
seribed a well, nearly 400 feet deep, at Yakitsk in Siberia, in which 
the temperature of the soil at the bottom was found to be about the 
freezing point ;—and the object of the present communication is to ex- 
plain the measures taken by the Imperial Academy of Sciences at St. 
Petersburgh fully to investigate this point, to ascertain precisely, not 
only the law which regulates the temperature of the ground to the 
depth which is affected by the periodical change of summer and winter, 
but also the influence of the external air in penetrating into the sides 
of the well or shaft at Yakatsk; and, finally, to ascertain the depth 
which the summer heats generally reach. 

The experiments recommended for this purpose are, to introduce 
pairs of self-registering thermometers into the side of the well at the 
several depths of 1, 3, 5, 10, 20, 50, 100, 150, &e. to 350 feet; the 
thermometers to remain a whole year, and to be examined daily. M. 
Baer also points out the importance for physical geography, to ascer- 
tain the thickness of perpetually frozen ground in countries whose mean 
temperature is considerably below the freezing point; for if, as at 
Yakitsk, the ground never thaws at a depth of from 300 to 400 feet, 
all the small streams where superficial waters only are kept in a fluid 
state in the summer, must be in the winter entirely waterless ; and vice 
versd, we may conclude, that all rivers which do not come from the 
south, and whose course is entirely within those countries which pre- 
serve perpetual ground-ice, and yet do not cease to flow in the winter, 
must receive their waters from greater depths than those which remain 
in a frozen state. This circumstance is not devoid of interest in the 
theory of the formation of springs. Professor Baer also states that he 
is collecting materials to ascertain the southern limit of perpetual 
ground-ice ; and concludes with an appeal to Great Britain, whose ex- 
tensive possessions in North America afford so ample a field for 
experiment, to furnish a similar series of observations in the western 
hemisphere. 


Sketch of the recent Russian Expeditions to Novaia Zemlia—By 
Professor BAER. 


The object of this sketch was briefly to enumerate the different ex- 
peditions sent out by the Russian government, in order to illustrate a 
map of Novaia Zemlia, in which the outline of the islands is marked as 
represented in our most modern maps, and its actual outline as it is 
now known to exist; whence it appears that more than half the eastern 
portion of the land must be obliterated from our maps. 


TRANSACTIONS OF THE SECTIONS. 97 


Many curious details also were given with respect to the vegetation 
and climate of these regions, whose mean temperature appears to be 
that of the freezing point. 


A brief Account of a Mandingo, native of Nydéni-Mart, on the River 
Gambia, in Western Africa. By Captain Wasuincrton, R. N. 


Although the special object of our inquiries, as geographers, is the 
surface of the earth we inhabit, yet, observes the author of this notice, 
it may be permitted to pause for a moment in our more ordinary re- 
searches for the purpose of contemplating a native of one of the little- 
known regions of western Africa, and to mark the vicissitudes in the 
life of a Mandingo, who in his native village had been in company 
with Mungo Park, one of the first and best of our African travellers, 
and successively to notice him as a slave, a soldier in the British army, 
a freeman, and, finally as about to return to the house of his fathers, 
and to impart to his countrymen some few of the blessings of civiliza- 
tion which he may have acquired during an absence of more than a 
quarter of a century from the land of his birth. 
It were needless here to enter into any detail of the life of Mo- 
hamed-u Sisei ; suffice it to observe, that the chief points of geographi- 
cal interest are, that we have been enabled to obtain from him some 
itineraries in the country of Senegambia, noting places not to be 
found in our maps, but more especially a vocabulary of more than 
2000 words and phrases in the Mandingo tongue; and when we con- 
sider how extensively diffused is this language, perhaps the most so 
of any of the thirty-six families of language into which authors have 
classified the 115 languages (not dialects) of Africa, and that hitherto 
a vocabulary of about 400 words is all that we possessed of it, it may 
perhaps be admitted that this native of the Gambia has not offered an 
unprofitable subject of geographical inquiry. 


On the recent Expeditions to the Antarctie Seas. By Captain 
WasuinecrTon, R. JN. 


This paper was illustrated by a South Circumpolar Chart on a large 
_ seale, showing the tracks of all former navigators to these seas, from 
_ Dirk Gherritz, in 1599, to M. d’Urville, in 1838, including those of 
Tasman, in 1642; Cook, in 1773; Bellingshausen, in 1820; Weddell, 
in 1822; Briscoe, in 1831: and exhibiting a vast basin, nearly equal 
in extent to the Atlantic Ocean, unexplored by any ship, British or 
_ foreign. The writer pointed out that the ice in these regions was far 
_ from stationary ; that Bellingshausen had sailed through a large space 
_ within the parallel of 60°, where Briscoe found ice that he could not 
_ penetrate; that where D’Urville had lately found barriers of field-ice, 
_ Weddell, in 1822, had advanced without difficulty to the latitude of 
_ ‘744°, or within 16 degrees of the pole; and that it was evident from 
the accounts of all former navigators, that there was no physical 
VOL. vil. 1838. H 


98 EIGHTH REPORT—1838. 


obstacle to reaching a high south latitude, or, at any rate, of ascertain- 
ing those spots which theory pointed out as the positions where, with 
any degree of probability, the southern magnetic poles will be found. 
The paper also mentioned the expedition to the South Seas, which has 
just left this country, fitted out by several merchants, but chiefly under 
_ the direction of that spirited individual, Mr. Enderby, whose orders 
were to proceed in search of southern land, and to endeavour to attain as 
high a south latitude as practicable; and concluded with an earnest 
appeal to the British Association, that the glorious work of discovery 
begun by our distinguished countryman, Cook, might not be left in- 
complete. Europe, the author observed, looks to this country to solve 
the problem of Terrestrial Magnetism in the southern hemisphere,—. 
and unanimously points to that individual who has already planted the 
“red cross of England” on one of the northern magnetic poles, as 
the officer best fitted to be the leader of an expedition sent out for 
such a service. 


A Summary Account of the various Government Surveys in Europe, 
illustrated by specimens of the Maps of England, France, Austria, 
Saxony, Tuscany, $c. §e. By Captain Wasuincton, R. N. 


On the recent Government-map of Mexico. By Lieutenant-Colonel 
VELASQUEZ DE LEON. 


A brief notice was given of a map of the state of Mexico which has 
been constructed within the last few years. The sites of the coal 
mines near Chilpanzingo, about 100 miles south of Mexico, the iron 
mines of Amilpas, and the tin mines of Acambay, near the north- 
western frontier, were specified. 


Sketch of the Progress and Present State of the Trigonometrical Survey 
in India. By Major Jervis, Surveyor- General. 


The author of this paper first gave a rapid but comprehensive sketch 
of the physical geography of India, noting its coast line, its elevated 
table lands, and the mountainous region of the Himalaya; he then 
drew attention to the origin, in 1759, and to the progress, of the mea- 
surement of the great meridional are of 1320 geographical miles in 
length, extending from Cape Comorin on the south, to the foot of the 
Himalaya, and effected by Colonels Lambton and Everest ; and con- 
cluded by an appeal to the British Association, that through their 
recommendation the future progress of that survey should be conducted 
in accordance with the present state of science in this country, and in 
a manner worthy of the munificent liberality of the East India Com- 
pany, by whose orders this great national work has been undertaken 
and carried into execution. 


a 


TRANSACTIONS OF THE SECTIONS. 99 


On the Construction of a Map of the Western portion of Central Africa, 
showing the probability of the River Tchadda being the outlet of the 
Lake Tchad. By Captain W. Auten, R. N. 


In this paper, the author gave a summary of the reasons, derived 
from Arabic as well as modern authorities, and from his own personal 
experience on the river Quorra, as to the possibility if not probability 
of the course of the river Tchadda having been mistaken ; and that in- 
stead of flowing from west to east, as represented by Denham, that it 
flows from east to west and joins the rivers Shary and Quorra, thereby 
affording water communication to the interior of central Africa. 


On the recently-determined Position of the City of Cuzco in Peru. 
By J. B. Pentiann, Esq. A. M. Consul: n Bolivia. Communicated 
by Captain BEaurort, Royal Navy, Hydrographer to the Ad- 
miralty. 

We learn from this brief notice that the position of the ancient tem- 
ple of the Sun at Cuzco is in 13°30'55" south latitude, 72° 4' 10! 
west longitude, differing full 45 miles from its position in our present 
maps; and that it stands at an elevation of 11,380 feet above the level 
of the sea. Mr. Pentland has also determined the positions of all 
principal places between La Paz and Cuzco, and of the western shores 
of the great inter-alpine lake of Titicaca. 


On the recent Ascent of the River Euphrates. By Lieutenant Lyncu. 
Communicated by Lieutenant-Colonel Cursney, Royal Artillery. 


This letter, dated Hit, June 1, 1838, described the facility with 
which the steamer had ascended the river from Basrah to that place. 
Between Hillah and Hit, it speaks of a broad, deep, and beautiful 
stream, in some of the bends nearly a mile wide ; the country extremely 
fertile; the crops of corn abundant, and just reaped; the population of 
Arabs along the banks extensive, and apparently happy, welcoming 
the approach of the steamer with shouting and dancing, and supplying 
their want of fuel with great readiness and cordiality. The produc- 
tions of the country, as wool, naphtha, bitumen, ghi (or butter), tallow, 
corn in abundance, and horses of the finest breed, are mentioned as 
easy to be obtained, and in large quantities; and the letter concludes 
with an expression of the writer’s conviction that a profitable trade 
might easily be established; and, after the experience he has had of the 
river, that there are no physical obstacles to its free navigation with 
properly constructed vessels. 

An explanation was then given of maps which were exhibited, and 
particularly of that showing the line of levels carried between the 
Mediterranean at Iskenderan, and the river Euphrates at Birehjik, 
whence it appears that the city of Antioch is situated 300 feet above the 
sea; the town of Birehjik, 628 feet ; and the highest point between the 
sea and the river rises 1720 feet above the Mediterranean, 

H@ 


i 


100 EIGHTH REPORT—1838. 


ZOOLOGY. 


On the Wild Cattle of Chillingham Park. By J. HtnpMarsn, of 
Alnwick. : 


The author stated that he had been obligingly assisted in his present 
attempt to give an account of the wild cattle of Chillingham, by the 
following communication from their noble proprietor : 


“ Grosvenor Square, 8th June, 1838. — 

* Sir,—Some time since I promised to put down upon paper what- 
ever I knew as to the origin, or thought most deserving of notice, in 
respect to the habits and peculiarities of the wild cattle at Chillingham. 
I now proceed to redeem my promise, begging pardon for the delay. 
In the first place, I must premise that our information as to their origin 
is very scanty; all that we know and believe in respect to it rests in 
great measure on conjecture, supported, however, by certain facts and 
reasonings, which lead us to believe in their ancient origin, not so much 
from any direct evidence, as from the improbability of any hypothesis 
ascribing to them a more recent date. I remember an old gardener of 
the name of Moscrop, who died about thirty years ago, at the age of 
perhaps eighty, who used to tell of what his father had told him as hap- 
pening to him, when a boy, relative to these wild cattle, which were 
then spoken of as wild cattle, and with the same sort of curiosity as 
exists with regard to them at the present day. In my father’s and grand- 
father’s time we know that the same obscurity as to their origin pre- 
vailed ; and if we suppose (as was no doubt the case) that there were 
old persons in their time capable of carrying back their recollections 
to the conversation still antecedent to them, this enables us at once to 
look back to a very considerable period, during which no greater know- 
ledge existed as to their origin than at the present time. It is fair, 
however, to say, that I know of no document in which they are men- 
tioned at any past period. Any reasoning, however, that might be 
built on their not being so noticed, would equally apply to the want 
of evidence of that which would be more easily remembered or recol- 
lected—the fact of their recent introduction. The probability is, that 
they were the ancient breed of the island, inclosed long since within 
the boundary of the park. Sir Walter Scott rather particularly sup- 
poses that they are the descendants of those which inhabited the Great 
Caledonian Forest, extending from the Tweed to Glasgow, at the two 
extremities of which, namely, Chillingham and Hamilton, they are 
found. 

“J must observe, however, that those of Hamilton, if ever they were 
of the same breed, have much degenerated. 

“The park of Chillingham is a very ancient one. By a copy of the 
endowment of the vicarage, extracted from the records of Durham, 
and referring to a period certainly as early as the reign of King John, 
about which time, viz. 1220, the church of Chillingham was built, the 


TRANSACTIONS OF THE SECTIONS. 101 


vicar of Chillingham was, by an agreement with Robert de Muschamp, 
to be allowed as much timber as he wanted for repairs, of the best oak 
out of the Great Wood of Chillingham, the remains of which were ex- 
tant in the time of my grandfather. The more ancient part of the 
castle also appears to have been built in the next reign, that of Henry 
IIL, since which it has been held, without interruption, by the family 
of Grey. At what period, or by what process, the park became in- 
closed, it is impossible to say; but it was closely bounded by the do- 
mains of the Percies on the one side, and by the Hibburnes on the 
other, the latter of whom had been seated there since the time of King 
John; and as the chief branch of the Greys always made Chillingham 
their principal residence, until it passed into the hands of Lord Ossul- 
ston, by his marriage with the daughter and heiress of Ford Lord Grey, 
it is reasonable to suppose that, in order to secure their cattle, wild and 
tame, they had recourse to an inclosure probably at an early period. 
It is said there are some other places in which a similar breed is found : 
Lyme Park, in Cheshire ; Hamilton, as I before mentioned ; and Chart- 
ley Park (Lord Ferrers). The first I have not seen, but they are de- 
scribed as of a different colour, and different in every respect. ‘Those 
at Hamilton, or rather Chatelherault, I have seen, and they in no de- 
gree resemble those at Chillingham. They have no beauty, no marks 
of high breeding, no wild habits, being kept, when I saw them, in a 
sort of paddock; and I could hear no history or tradition about them, 
which entitled them to be called wild cattle. Those at Chartley Park, 
on the contrary, closely resemble ours in every particular; in their 
colour, except some small difference in the colour of their ears—their 
size—general appearance; and, as well as I could collect, in their 
habits. This was a very ancient park, belonging formerly to Deve- 
reux, Earl of Essex, who built the bridge on the Trent, to communi- 
cate with his chace at Channock and Beaudesert, then belonging to 
him; and the belief is, that these cattle had been there from time im- 
memorial. With respect to their habits, it is probable that you will 
learn more from Cole, who has now been park-keeper at Chillingham 
for many years, than from any information J can give. I can mention, 
however, some particulars. They have, in the first place, pre-emi- 
nently, all the characteristics of wild animals, with some peculiarities 
that are sometimes very curious and amusing. They hide their young, 
feed in the night, basking or sleeping during the day; they are fierce 
when pressed, but, generally speaking, very timorous, moving off on 
the appearance of any one, even at a great distance. Yet this varies 
very much in different seasons of the year, according to the manner 
in which they are approached. In summer, I have been for several 
weeks at a time without getting a sight of them, they, on the slightest 
appearance of any one, retiring into a wood, which serves them as a 
sanctuary. On the other hand, in winter, when coming down for food 
into the inner park, and being in contact with the people, they will let 
you almost come among them, particularly if on horseback. But then 
they have also a thousand peculiarities. They will be feeding some- 
times quietly, when, if any one appear suddenly near them, particu- 


102 EIGHTH REPORT—1838. 


larly coming down the wind, they will be struck with a sudden panic, 
and gallop off, running one after another, and never stopping till they 
get into their sanctuary. It is observable of them as of red deer, that 
they have a peculiar faculty of taking advantage of the irregularities 
of the ground, so that on being disturbed, they may traverse the whole 
park, and yet you hardly get a sight of them. Their usual mode of 
retreat is to get up slowly, set off in a walk, then a trot, and seldom 
begin to gallop till they have put the ground between you and them 
in the manner that I have described. In form, they are beautifully 
shaped, short legs, straight back, horns of very fine texture, thin skin, 
so that some of the bulls appear of a cream colour; and they have a 
peculiar ery, more like that of a wild beast than that of ordinary cattle. 
With all the marks of high breeding, they have also some of its defects. 
They are bad breeders, and are much subject to the rush, a complaint 
common to animals bred in and in, which is unquestionably the case 
with these as long as we have any account of them. When they come 
down into the lower part of the park, which they do at stated hours, 
they move like a regiment of cavalry in single files, the bulls leading 
the van, as in retreat it is the bulls that bring up the rear. Lord Os- 
sulston was witness to a curious way in which they took possession, as 
it were, of some new pasture recently laid open to them. It was in 
the evening about sunset. They began by lining the front of a small 
wood, which seemed quite alive with them, when all of a sudden they 
made a dash forward altogether in a line, and charging close by him 
across the plain, they then spread out, and after a little time began 
feeding. Of their tenacity of life the following is an instance. An old 
bull being to be killed, one of the keepers had proceeded to separate 
him from the rest of the herd, which were feeding in the outer park. 
This the bull resenting, and having been frustrated in several attempts 
to join them by the keeper's interposing, (the latter doing it incautious- 
ly,) the bull made a rush at him and got him down; he then tossed 
him three several times, and afterwards knelt down upon him, and 
broke several of his ribs. There being no other person present but a 
boy, the only assistance that could be given him was, by letting loose 
a deer-hound belonging to Lord Ossulston, which immediately attacked 
the bull, and by biting his heels drew him off the man and eventually 
saved his life. The bull, however, never left the keeper, but kept con- 
tinually watching and returning to him, giving him a toss from time to 
time. In this state of things, and while the dog with singular sagacity 
and courage was holding the bull at bay, a messenger came up to the 
castle, when all the gentlemen came out with their rifles, and com- 
menced a fire upon the bull, principally by a steady good marksman 
from behind a fence at the distance of twenty-five yards; but it was 
not till six or seven balls had actually entered the head of the animal, 
(one of them passing in at the eye,) that he at last fell. During the 
whole time he never flinched nor changed his ground, merely shaking 
his head as he received the several shots. Many more stories might 
be told of hair-breadth escapes, accidents of sundry kinds, and an end- 
less variety of peculiar habits observable in these animals, as more or 


= 


TRANSACTIONS OF THE SECTIONS. 103 


less in all animals existing in a wild state: but, I think I have recapi- 
tulated nearly all that my memory suggests to me, as most deserving 
of notice; and will only add, that if you continue in the intention of 
preparing a paper to be read before the approaching Scientific Asso- 
ciation at Newcastle, on this subject, you are welcome to append this 
letter to it, as containing all the information I am able to give.—I have 
the pleasure, &c., ) 
“ TANKERVILLE. 


“To J. Hindmarsh, Esq.” 


In addition to this letter, Mr. Hindmarsh communicated some in- 
formation collected from Mr. Cole, the keeper, and from his own ob- 
servation. There are about eighty in the herd, comprising twenty-five 
bulls, forty cows, and fifteen steers, of various ages. The eyes, eye- 
lashes, and tips of the horns alone are black, the muzzle is brown, 
the inside of the ears red or brown, and all the rest of the animal 
white. Even the bulls have no manes, but a little coarse hair on their 
neck. They fight for supremacy, until a few of the most powerful 
subdue the others, and the mastery is no longer disputed. When two 
bulls are separated by accident, they fight when they meet, although 
friendly before, and do so till they become friends again. The cows 
commence breeding at three years old ; the calves suckle nine months ; 
they conceal their calves for a week or ten days after they are born, 
suckling them two or three times a day. The late Mr. Bailey, of Chil- 
lingham, found a calf, two or three days old, very poor and weak. On 
stroking it, it retired a few paces, and then bolted at him with all its 
force ; he stepped out of its way, and it fell down, when the whole flock 
came to its rescue, and forced him to retreat. They do not often die 
from disease, but they are seldom allowed to live more than eight or 
nine years, at which period “they begin to go back.” When slaugh- 
tered, they weigh from 38 to 42 stones. One was caught and kept, 
and became as tame as the domestic ox, and thrived as well as any 
short-horned steer could do, and, in its prime, was computed to weigh 
65 stone. They are shy in summer, but tame in winter, and will eat 
hay from a fold, although they will not taste turnips. When one of 
the herd becomes weak or feeble, the rest set upon it and gore it to 
death. At the end of the last century similar cattle existed at Burton 
Constable, Yorkshire, and at Dunnlary, in Dumfries-shire, but these 
are now extinct. 

The author quoted a passage from Boetius, which, allowing for a 
little colouring, described these animals very well, except in the non- 
existence of a mane. The cattle at Dunnlary had black ears, but in 
all other points resembled those of Chillingham; and this may be ac- 
counted for by a statement of Bewick, that about forty years ago some 
of the animals had black ears at Chillingham, and were shot by the 
keeper. On the whole, the author was inclined to think these animals 
the survivors of the Caledonian cattle, which undoubtedly extended 
through the northern provinces of England; and that, under the pro- 


104 EIGHTH REPORT—1838. 


tection of the owners of Chillingham, they had escaped the general 
destruction consequent on the advancement of civilization, in the 
country. 


On a rare Animal from South America. By Lieut.-Colonel Syxes, 


The animal in question was described by Azara as Canis jubatus ; 
but the description given by Azara himself led the author to suppose 
it ought not to be placed in that genus. It differed from the dog tribe 
in its nocturnal and solitary habits: it had a long mane, its tail was - 
thicker and more bushy, the head flatter, the eyes smaller, the nose 
sharper, and the whole animal more bulky than the dog tribe. If it 
differed from the dog, it differed more from the fox and wolf; and he pro- 
posed to refer it to the genus hyzna, or, if this could not be admitted, he 
would make it a distinct genus, which would then be the representative 
of the hyzna tribe in America, which we must suppose possessed some 
analogue of that tribe in the old world. Colonel Sykes also exhibited 
the skin of a European Felis, which Temminck names Felis pardina, 
and states is known as the lynx of Portugal: it is not, however, known 
by this name amongst London furriers. 


On certain Species of Sorex. By Rev. L. Jenyns, F.LS. 


The Rey. L. Jenyns exhibited a series of specimens of the square-tailed 
shrew (Sorex tetragonurus, Herm.) and pointed out the distinguishing 
characters between it and the common shrew (S. rusticus, Jen.). He 
also exhibited a specimen of the chestnut shrew (S. castaneus, Jen.) 
which he had formerly considered as a mere variety of the S. tetrago- 
nurus, but of which he had now seen three individuals, and which he 
was satisfied deserved to rank as a distinct species. It is principally 
characterized by the bright chestnut colour of the upper parts, though 
there are other differences in the tail and in the form of the cranium. 
It was observed generally that the characters of the cranium were 
found of great assistance in determining the several species of this ge- 
nus.—Mr. Jenyns also exhibited two undeseribed species of the genus 
Cimez as restricted by entomologists of the present day. One of these, 
which has been alluded to by Latreille, though never characterized, 
was found inhabiting in great numbers the nests of the common house 
martin. The other was taken from a Pipistrelle Bat. It was proposed 
to call these two species C. hirundinis and C. pipistrelli. At the same 
time the peculiar characters were pointed out, by which each was di- 
stinguished from the other, as well as from the C. /ectularius of authors, 
or common Bed-bug. 


TRANSACTIONS OF THE SECTIONS. 105 


On Marsupiata. By Professor Owrn, FBS. Sc. 


Mr. Owen briefly stated the results he had come to in the course of 
his investigation of these animals, under the three following heads: 
first, the zoology of Marsupiata; secondly, their relation to other 
Mammalia; and, thirdly, the peculiarities of their reproductive econo- 
my. 1. With regard to their zoological characters, they present as 
many forms, and as varied habits, as all the Carnivora put together. 
In their kind of food they are very various. Some are entirely car- 
nivorous, as those of New Holland. Some are insectivorous, like the 
Orycteropus and Myrmecophaga, among the other Mammalia. A spe- 
cies of these is described by Captain King, as having a divided hoof like 
the Ruminantia. Some of them are arboreous, as the Didelphes and 
Perameles. Many of the Marsupiata are strictly herbivorous, as the 
Kangaroo-rat, &e. Mr. Owen thought, however, with all the varieties 
of character and habit presented by these animals that they had been 
too largely subdivided by zoologists. 2. In regard to their relation to 
other animals, he was of opinion, that they ought to be considered 
as one group; for although they differed greatly in some respects, 
still they agreed in so many remarkable points, that they could not be 
consistently separated. Of these points the most remarkable were the 
development of the hind legs; the existence of the marsupial bag; the 
circulatory apparatus being less perfect than in the rest of Mammalia, 
the blood being returned to the heart by two veins, as in the hearts of 
reptiles and birds; and in the hemispheres of the brain, which are not 
united by a corpus callosum. In this last respect, they are like the 
oviparous division of vertebrate animals, a fact first pointed out by 
Mr. Owen ; having the same relation to Mammalia, that the Batrachians 
have to the Ophidian, Saurian, and Chelonian divisions of reptiles. 3. 
The reproductive economy of these animals was slightly touched upon. 
It had been supposed, that the young were produced by budding from 
the marsupial pouch ; but this was now proved to be erroneous, and the 
first stages of their uterine growth were known to be like that of other 
Mammalia. 

Mr. Owen then entered into some geological account of these animals. 
Dr. Buckland had found the jaw of an animal in the Stonesfield strata, 
which, from a peculiar mark only seen in the jaw of Marsupiata, could 
be well identified, and proved to be analogous to the present genus 
Opossum, or Didelphis. Major Mitchell has in his collection a large 

_ number of bones belonging to extinct genera of Marsupiata. From the 

jaw of one of these animals, there is reason to conclude, that its pos- 
sessor must have been double the size of any species of kangaroo ex- 
isting at the present time. 


On Pouched Rats. By J. Ricuarvson, M.D., F.R.S., §e. 


Dr. Richardson exhibited four very distinct species of American 
pouched rats, or gophers, belonging to the genus Geomys. 


< ; 


106 EIGHTH REPORT—1838. 


Remarks on the Greenland and Iceland Falcons. By Joun Hancock. 


On the question of the specific identity or difference of these birds, 
Mr. Hancock, in opposition to some English writers, has arrived at the 
conclusion that they are truly distinct. This opinion he has formed 
from an examination of many individuals of the Iceland and Greenland 
birds, his attention having been first awakened to the subject by a sight 
of two individuals brought from Iceland in 1833 by Mr. G. C. Atkinson. 
Besides various other specimens, minutely described by Mr. Hancock, 
he was fortunate enough to be furnished, by the exertions of Mr. W. 
Procter, who visited Iceland last year, with an opportunity of inspeeting 
a ‘brood’ of five Iceland falcons, viz. the parents and three young 
ones, which Mr. Procter shot on the same crag. 

On comparing the male, female, and young of these gray Iceland 
birds with the corresponding white falcons of Greenland, the differences 
became manifest, and Mr. Hancock endeavoured to show, by an investi- 
gation of other allied species, that the supposition of continual change 
of plumage, after maturity, by which it has been attempted to account 
for these differences, is not tenable. Mr. Hancock does not admit a 
white variety of the Iceland falcon, and thinks it doubtful whether this 
bird inhabits Greenland; while the white bird of Greenland is rare in 
Iceland, except during winter and on the northern parts of the island. 

The author concluded his communication by a minute comparative 
description of the two birds. The following are characters of the ma- 
ture plumage :— 

Faleo Islandicus——Ground of the upper plumage, a dark lead or 
mouse colour, barred and spotted with cream colour; ground of 
the under parts, buff, marked with streaks, heart-shaped spots, and 
bars of dark mouse colour; wings reaching to within about 14 | 
inch of the end of the tail. Dimensions.—Adult male: length, 
1 foot 9+ inches ; extent of wings, 3 feet LO+, inches. Female: 
length, 1 foot 11 inches; extent of wings, 4 feet 2 inches; like 
the male, but darker. (The young have the bars on the middle 
two tail feathers discontinuous.) 

Falco Grenlandicus, Linn.—Ground of the plumage, pure white ; 
upper parts elegantly marked with arrow-shaped spots of a dark 
gray ; under parts and head streaked with the same ; wings reach- 
ing to within 2 inches of the end of the tail, second primary longest. 
Dimensions — Adult male: 1 foot 9 inches. Female: length, 1 
foot 11 inches; extent of wings, 3 feet 10 inches; like the male, 
but with more dark in the plumage. In some individuals the bill 
has two processes in the upper mandible. (The young have the 
bars on the middle two tail feathers continuous.) 


On the Ardea Alba. By AntHuR STRICKLAND. 


Mr. Strickland stated, that this bird had been unjustly excluded from 
the catalogue of occasional visitors to this country by late authors, as 
he could prove on unquestionable authority, that it had been killed of 


, * 
ve i 
3 


: TRANSACTIONS OF THE SECTIONS. 107 


late years in more cases than one. The first instance was twelve or 
thirteen years ago: a bird of this species was seen for some weeks about 
Hornsea Moor in the East Riding of Yorkshire; it was some time after 
presented to the author, in whose collection it is at present, in perfect 
preservation. Another, in full summer plumage, was killed by a la- 
bourer in the fields of James Hall, Esq., of Scorborough, near Beverley, 

about three years ago, and is now in the possession of that gentleman. 
Another specimen of this bird is in the collection of Mr. Foljambe, of 
Osberton, with a label on the case, stating it to have been killed near 
that place. A careful examination of these specimens will, Mr. Strick- 
Jand has no doubt, prove that this bird is properly separated from the 
large egret of North America, which has been frequently placed in our 
collections forthe British species. 


On a species of Scyllium, taken on the Yorkshire Coast. By ARTHUR 
STRICKLAND. 


Mr. Strickland described a large fish of this genus, which had been 
caught in Bridlington Bay on the 11th August, 1838. 


— 


On the Toes of the African Ostrich, and the number of Phalanges in 
the Toes of other Birds. By T. Auuts. 


__ The author’s attention was directed to this subject by Dr. Riley, of 
Bristol, who had stated at one of the meetings of the British Association, 
that he had found the rudiments of a third toe in the ostrich. Neither 
in the specimens which he has piaced in the Museum at York, nor in 
one that he obtained lately, for the express purpose of looking for this 
‘rudimentary toe, has he been able to discover any thing like this third 
“member of the foot. He further stated, that Cuvier had given the 
“number of the phalanges of the toes wrong in the following birds. In 
the cassowary, which has three toes, the real numbers of the phalanges 
are three, four, and five. In the ostrich, four and five. The Capri- 
“tmulgus has the outer and middle toe, having four phalanges each. The 
swift has only three phalanges, except in the hallux. The humming- 
bird has the full number of phalanges in all its toes. 


A. 
i On Tetrao Rakelhahn. By Evwarp Cuaruton, M.D. 


__ Dr. Charlton, in this communication, described the appearance of two 
‘individuals of the species or variety of Tetrao above named, and assigned 
the reasons which induce him to believe that it is a hybrid between the 
_Tetrao urogallus and Tetrao tetriz. In favour of this opinion he 
“quotes Bechstein and Nillson, though on the other side Temminck de- 
scribes the bird as a distinct species. Mr. Charlton stated that he found 
the Norwegian peasantry perfectly aware of the existence of this hybrid, 
giving to it the name of ‘ Rockelhanar.’ 


108 EIGHTH REPORT—1838. 


Notice of the Annual Appearance on the Durham Coast of some of the 
Lestris tribe. By Epwarp BackHouse. 


The author stated, from observations made during a series of years, 
while occasionally residing in the neighbourhood of the Tees’ mouth, 
that the Lestris Richardsonii is the earliest of the genus in its appear- 
ance on these shores when on its southern migration. 

The young birds seem usually to arrive in the beginning of Septem- 
ber, and in the middle of the same month the adults, accompanied by 
the young of the Lestris Pomarinus, make their appearance, generally 
continuing for about three weeks, when they are succeeded in the mid- 
dle of October by the mature Pomarine Skuas; these, as far as Mr. 
Backhouse has been able to discover, continue for the like space of 
three weeks and then disappear. 

He last year met with Lestris Pomarinus in its mature state in con- 
siderable abundance off Hartlepool and the Tees’ mouth. 

Early in the autumn of 1836, while at the same place, he obtained 
one of the Lestris tribe which materially ciffered from any he had be- 
fore met with. 

This specimen is in the immature plumage, very much resembling 
in its markings the young of Z. Pomarinus. In size and proportions 
it nearly approaches LZ. parasiticus; and having recently compared it 
with a nearly mature specimen of Z. parasiticus, also shot on the coast 
of Durham, now in the collection of Mr. John Hancock of Newcastle, 
he is induced to conclude it to be the young of that bird. 

Its admeasurements are as under, viz. :— 


Length front bat to tall Hiroe Se eG ells na od 17 inches. 
Expanded wings . . 32 

Elongated tail feathers, rounded at the end, project $ths of an inch. 
Bill, from forehead to ay nearly 1 inch. 
Length’ of tarst) S00 Gs Tied Salah. ahs Pez0 13 inch. 


He also stated that ZL. cataractes was met with, though rarely, on 
this coast. 

The paper was accompanied ail drawings and stuffed specimens of 
the various species. 


On a New Species of Smelt from the Isle of Bute. 
By W. Yarrec1, F.L.S. 


In the month of November, 1837, Mr. Yarrell received from W. 
Ewing, Esq., of St. Vincent Street, Glasgow, a specimen of a smelt, 
which was at the first glance so obviously different from our well-known 
and esteemed favourite, as at once to claim for it the title of a distinct 
species ; and the specimen was the more interesting from the circum- | 
stance that this fish is not only new to our own country, but is also. 
entirely new to ichthyology, no second species of the genus Osmerus — 
having hitherto been made known. 

The gentleman just named passed part of the summer of 1837 near 


TRANSACTIONS OF THE SECTIONS. 109 


Rothsay in the isle of Bute, and the fish in question was brought to 
him by a fisherman, who stated that he caught it on a hand-line in the 
bay of Rothsay about 200 yards from the shore, in twelve-fathom wa- 
ter; that it was, though well known, but rarely seen; that specimens 
varied from 62 to 8 inches in length; that they were full of roe in 
June, and when first caught the cucumber-like smell was very apparent. 

Mr. Yarrell thus describes the characters of this new species of Osme- 
rus, for comparison with the common smelt :—In the new fish the jaws 
are of equal length, without teeth upon either, but there are four long 
teeth upon the tongue ; the eye very large; the upper surface of the head 
convex ; the form of the operculum circular ; the dorsal fin commencing 
half-way between the point of the nose and the anterior edge of the adi- 
pose fin; the anterior edge of the adipose fin is at the end of the second 
third of the space between the dorsal fin and the end of the fleshy por- 
tion of the tail, while the ventral fins, which are in the middle of the 
whole length of the head and body in both species, are, by the proxi- 
mity of the first dorsal fin to the head in the new smelt, brought in a 
vertical line underneath the posterior edge of the first dorsal fin; the 
anal fin, like the adipose fin above it, commences much nearer the tail 
than in the common species ; the ends of the caudal rays not tipped with 
black. The numbers of the various fin rays are as follows :— 


D. Bien Ve 1 AEROS 
Osmerus vulgaris...» 11 11 8 15 19 
New species. ...... 11 14 812 12 19 


The form of the body is elongated and slender ; the lateral line straight ; 
above it the colour of the body is of a pale yellowish green; below it 
is a broad longitudinal stripe of bright silvery white, passing, by a shade 
of yellowish olive, to an iridescent silvery white on the belly. 

To identify this species with the locality from which it was derived, 
Mr. Yarrell proposes to distinguish it by the name of the Smelt of the 
Hebrides—Osmerus Hebridicus. 


On some new and rare British Fishes. By Ricuarp PARNELL, 
M.D. PRS LE. 


The author exhibited a large collection of British fishes, and read 
notes upon their specific characters and synonymy, which he proposed 
to embody in a work devoted to the Natural History of Fishes*. The 
species most copiously illustrated by Dr. Parnell’s observations, were 
Motella cimbria of Linnzeus, Pagellus acarine, Raia chagrinea, hitherto 
seen by very few naturalists, and Raia intermedia, which he thinks has 
not been previously described. 

- Besides various other interesting fishes, Dr. Parnell exhibited to the 
Section a dish of white bait (Clupea alba) which had been caught the 
preceding day in the Frith of Forth, and were recognized by Mr. Yar- 


f 5 The Natural History of the Fishes of the Forth, This interesting work is pub- 
shed. 


* 


110 , EIGHTH REPORT—1838, 


rell and other Ichthyologists present as identical with the fish of the 
Thames. 


Mr. Forbes stated, that he had lately taken off the Isle of Man two 
specimens of the lancelot. 


On the Sternoptixinee, a Family of Osseous Fishes. By P. D. 
Hanpysive, M.D., F.R.S.E., of Edinburgh. 


After giving a sketch of the history of this family, and especially- of 
the genus Sternoptix, Dr. Handyside entered into a minute description 
of a new species, which he proposed to call S. eelebes, distinguishing it 
from S. Hermani and S. Olfersii, to which it most nearly approached. 
He considered these three fishes to form a distinct group or sub-family 
of Salmonidz. 


Ona Fish with Four Eyes. By W.H.CiAarke and Joun Mortimer. 


In this communication the authors state, that at Fort Amsterdam 
(Surinam) shoals of small fishes appear periodically, having four di- 
stinect organs of vision. They observed that the water of the river, or 
rather estuary, on which the fort is built, was blackened for miles along its 
margin by innumerable multitudes of these fishes, which were followed 
by scarlet flamingos. The description given of these fishes agrees in 
several points with the character of the Anableps*, the only fish known 
to naturalists which, by the double pupils of its eyes, may deserve the 
title of tessarophthalmoid, proposed by the authors for the little fishes 
they observed. It is, however, stated in the paper, that the eyes of 
these fishes are really four, separated in two pairs by a transverse horny 
protuberance, and separately moveable. A drawing in pencil accom- 
panied the communication. 


— —_—_. 


On a new British Shell. By J.E.Gray, F.RS., §e. 


The shell in question had been discovered by Miss Isabella Mark in 
the stomach of a haddock taken on the coast of Northumberland, and 
it was believed had not hitherto been described. Mr. Gray proposed 
to make of it a new genus, which he would call Neara, and which 
would be peculiar for the slender produced form of the under edge, 
and the large size of the lateral teeth. He stated, that he knew 
two species belonging to the same genus, one from China figured by 
Chemnitz, and called Anatina rostrata, by Lamark ; and the other from 
the Adriatic, described and figured by Olivier, under the name of 
Tellina cuspidata, and that he was not certain, without comparison, that 
the British species was distinct from the latter. Mr. Gray also ex- 
hibited a very splendid specimen of Balanus scoticus, attached to a 


* Cobitis anableps, Zinn.; Anableps tetrophthalmus, Bloch, 


TRANSACTIONS OF THE SECTIONS. 111 


species of Fusus, which had been obtained from the museum of Mr. 
Fryer. 


On the Formation of Angular Lines on the Shells of certain Mollusca. 
By J. E. Gray, F.RS., ge. 


The annular marks, and those in the direction of the growth of the 
shell, and in the substance of the shell itself, are easily explained by 
the increased or diminished degree of activity of the secreting surface 
of the mantle. But the coloured angular lines are not so easily ex- 
plained. Mr. Gray supposed that the colouring of the shell was the 
consequence of glandular secretion ; that, as the shell increased in size, 
there was a tendency to divergence in the glands. He stated, that it 
frequently happened in the progress of growth, that these glands were 
obliterated, and the immediate consequence of this obliteration was the 
production of a new gland: this gland was double, and, as it had a 
tendency to diverge, it formed two angular lines which proceeded to a 
certain distance, when it met with a gland formed in a similar way to 
itself, and, on meeting, it became obliterated: after this obliteration, a 
new double gland was formed, which proceeded in the same mode as 
the first, and thus produced the angular coloured lines apparent on so 
many shells. 


Notice of the Wombat. By J. E. Gray, F.R.S., §e. 


Mr. Gray stated, that in the Museum of the Natural History Society, 
was the wombat which was sent by Bass to Bewick, and from which 


- he took his original description: from a misprint, this specimen was 


said to have more teeth than it really has; and, on this account, Illiger 
having seen a specimen of the wombat, supposed this must be another 
genus, and named this one in his work, Amblotis wombattus. The con- 
dition, too, of this specimen assisted in the mistake, for, having been 
originally kept in spirit, it had lost its true colour. 


On the Boring of Pholades. By J. E. Gray, F.RS., &c. 


A difference of opinion prevails as to whether the action of these 
animals in excavating the rocks in which they are found is chemical 
or mechanical. At one time Mr. Gray was inclined to think it was 
the former; however, he had lately an opportunity of remarking the 
action of these animals in the chalk at Brighton, and he now believed 
it to be mechanical. He then exhibited several specimens of chalk 
which had been bored by the pholas, and pointed out some circular 
grooves which were made in their interior by spines on the outside of 
the shell, as well as a central impression produced by an elongation of 
the shell to a point at its inferior surface. He stated that the animal 
did not occupy the whole of the cavity it made, but the upper part 
only. Why he had formerly supposed the action of these animals on 


112 LIGHTH REPORT—1838. 


the rocks to be chemical was, that the patella was known to bore; and 
this would be impossible by the action of its flat shell. There was a 
little annelide, called Diplotis, which made elongated cavities in rocks. 
Now this animal had no shell, and its action must of course be 
chemical. 


On the Distribution of Terrestrial Pulmonifera in Europe. 
By Epwarp Forsss, F.L.S. 


For the purpose of stimulating zoologists to the investigation of the 


distribution of the terrestrial and fluviatile Mollusea in Great Britain, | 


and the collection of data for that object, Mr. Forbes presented a 
sketch of the laws which apparently regulate the distribution of ter- 
restrial Pulmonifera in Europe. ‘“ At present,” he observes, “the ma- 
terials are few for such an investigation, and most of the published ca- 
talogues are almost unavailable from the authors not having guarded 
against certain sources of fallacy.” These Mr. Forbes points out in 
order that they may be avoided in future. 

Instead of the political and artificial divisions for which European 
local catalogues are published, the author proposes to consider the dis- 
tribution of terrestrial Mollusca according to natural districts, and pre- 
sents the following classification as suited to Europe : 

Ist district. The greater part of Scandinavia, Iceland, the north of 
Russia, Scotland, probably Ireland, and the greater part of England. 

2nd district. Germany (except Austria), the south of Sweden and 
Denmark, the south of England, northern and central France, the chief 
part of Switzerland. 


3rd district. The peninsula of Spain and Portugal, the south of ,— 


France, the west of Italy, the western Mediterranean Isles, Africa, Bar- 
bary States, the Canaries. : 

4th district. Dalmatia, Wallachia, Turkey, Greece, the eastern Me- 
diterranean Isles, Asia Minor, Syria. 

5th district. Southern and eastern Russia, as far as Caucasus, ex- 
tending into Asia in Georgia. 

6th district. Austria, Styria, Croatia, Carniola, appear, by. their 
peculiar conchological products, to be in this point of view a separate 
district. 

“ Each of these great divisions has a conchological character of its 
own; in some certain genera prevail, in others certain species ; these 
divisions may be regarded as climates, and the Flora of each will be 
found to correspond in its distribution with the Fauna.” 

The author pointed out certain defects in the ordinary form of local 
catalogues, and suggested the introduction of notices of the soil, rock, 
frequency of occurrence, influences on distribution, variations of form, 
&c., and proposed a series of queries relating to Mollusca in furtherance 
of his general object. 


OO ae 


aa 


TRANSACTIONS OF THE SECTIONS. 113 


Remarks on the Modern Classification of Insects. 
By Rev. F. W. Horst, F.R.S. 


The following is an outline of the communication :—1st. That mo- 
dern entomologists, in their arrangements, have attended almost en- 
tirely to external organization. 2ndly. Internal organization has only 
been partially attended to: the alimentary canal, on which much stress 
is placed, cannot be considered as a criterion of an animal or a vege- 
table feeder, and is ill-adapted for the classification of insects. 3rdly. 
No uniform principle of arrangement has been entirely carried out: 
all have been interfered with by the introduction of other principles of 
secondary and minor importance. 4thly. It is only from increased 
attention to the Nervous System that we can expect a more natural 
system than what exists at present.—The author illustrated his posi- 
tions by extensive tables of genera. 


On the Noxious Insects which have this year (1838) seriously injured 
the Apple Trees and Hops. By the Rev. ¥. W. Hors, F.R.S. 


Mr. Hope described the Aphides as unusually destructive to various 
species of plants. An insect named ZVipula Tritict has appeared in 
great abundance in some parts of the counties of Hereford, Worcester, 
Gloucester, and Salop. From an examination of various samples of 
wheat submitted to Mr. Hope, it appears that the damage done by the 
Tipula is less than in previous years. 


Mr. Wailes and Mr. Charles Adamson exhibited the two sexes of the 
rare insect Psalidognathus Friendii, found in the-interior of a decayed 
palm tree in South America. 


On a new Species of Goliathus and some Lucani, from the Coast of 
Africa. By J. A. TURNER. 

The goliathus belongs, it was stated, to the genus constituted by the 
Rey. F. W. Hope, under the title of Dicronorhina. Some other la- 
mellicorn beetles were exhibited, especially two splendid Lucani, all 
from Southern Africa. 


a ed 


On the Gemmiferous Bodies and Vermiform Filaments of Actinie. 
By T. P. TEALE. 


The author stated, that as great differences of opinion existed amongst 
zoologists as to the nature of the gemmiform bodies and vermiform 
appendages of Actiniz, he had undertaken their investigation. Some 
general remarks on the structure of Actinize were premised, the author 
pointing out, by means of a large diagram, the various directions of the 
muscular septa, some lining the cavity and supporting the stomach of 

VOL. VII. 1838. I 


ie 


114 EIGHTH REPORT—1838. 


the animal, whilst others more delicate terminated in a mesentery, sup- 
porting the gemmiferous bodies, or what has been erroneously called 
the ovary. The division of the stomach into two lateral parts, giving 
to the whole animal a bilateral symmetry, was pointed out. 

The Gemmiferous bodies are about 200 in number, and appear as 
elongated masses attached along the inner border of most of the leaf- 
lets. Each is composed of several horizontal folds or plaits, which, 
when carefully unfolded, may, by the assistance of a lens, be seen to 
consist of two delicate layers of membrane, enveloping one closely 
compacted layer of gemmules. After enveloping the gemmules, the 
membranous layers become placed in opposition, and form the mesen- 
tery, by which the gemmiferous body is attached to the leaflet. The 
gemmules are round, except in an advanced stage of development, 
when their outline becomes interrupted by the pressure of neighbour- 
ing gemmules. A well-marked central depression may also be seen 
indicating the situation of the oral aperture, but without tentacula ; 
when of large size, they form considerable depressions in the gem- 
miform bodies, protruding before them their delicate investing mem- 
brane. In this state, they are readily detached by the point of a 
needle. ‘Their size is nearly uniform, except a few small ones, scat- 
tered very generally amongst the whole. There is no gradation in size 
amongst them, as if they successively arrived at maturity, as imagined 
by Dr. Spix. Some of the gemmules are, however, less developed than 
others ; and at the same season of the year, it is not uncommon to find 
individuals with the gemmules in very different stages of development, 
and this is not limited to any particular season. The colour of the 
gemmules varies considerably. The Vermiform Filaments.—They are 
attached by a delicate mesentery to the internal border of each gem- 
miferous body; they are formed of numerous convolutions extending 
from the superior to the inferior part of the gemmiferous body. They 
are of a milk-white colour, about as thick as a horse-hair, extremely 
soft, yielding readily to pressure with a needle. Superiorly, the fila- 
ments are very minute, so that their origin cannot be detected. In- 
feriorly, they are of larger size and less convoluted, passing in a simple 
wavy line to the stomach, where they terminate. During life, these 
filaments exhibit a distinct vermicular motion, even after removal from 
the animal. On removing some from the animal, and placing them in 
sea-water, they exhibited considerable locomotive power, which lasted 
for some time, when their outline became obscured, and in twenty-four 
hours nothing remained but a whitish floceulent substance. This struc- 
ture is best seen in its living state. In fresh water it decomposes in 
half an hour, but in proof spirit less rapidly. The author has succeeded 
in preserving it best by spreading the filament and its mesentery 
upon glass, upon which they may be dried. The function of these 
filaments is involved in obscurity. By many, they have been regarded 
as oviducts, but this the author thinks is very improbable, both from 
the minuteness of their terminations, the size of the gemmules, and the 
fact of ova never having been detected in them. In fact, the repro- 
duction of Actiniz must be looked upon as a strictly internal gemmi- _ 


7 


meen ae we 


TRANSACTIONS OF THE SECTIONS. 115 


parous process, in which the gemmules, when sufficiently matured, burst 
their envelope, and become lodged in the interseptal spaces, where they 
are exposed to the access and continued supplies of sea-water, the grand 
stimulus to their future development. In the absence of any direct 
evidence as to the nature of ihe vermiform filaments, the author sus- 
pects that they are elongated follicular glands, analogous to the sali- 
vary, pancreatic, and hepatic follicles of animals a little higher in the 
seale of organization, supplying secretions subservient to the digestive 
process. 


A drawing was exhibited, and a description given, of a new species 
of Ascaris, discovered by Dr. Bellingham, which he called A. alata. 
The distinctive character of this species was, that its posterior extre- 
mity was larger than its anterior. 


—— 


On certain Monstrosities of the Genus Encrinus. By G. B. 
Sowersy, F.L.S. 

Mr. Sowerby’s immediate object was to point out certain monstrosi- 
ties to which the Anerinus moniliformis is subject, which chiefly af- 
fect the arms. The plates of the pelvis (Miller) are also affected in 
number and somewhat in form. 

The radiaria are usually divided by five, i.e. the normal number of 
plates of the pelvis is five ; though there are not wanting instances of 
genera whose pelvis consists of only three plates: we shall, however, 
find that even these return to the normal number (Pentatrematites), for 
they have five scapulars, ten intercostals, &c. In Hncrinus the normal 
number of pelvic plates is five, the costals five, and the scapulars five ; 
these are then usually divided, so that there are usually ten arms setting 


_ off from the five scapulars. One of the monstrosities in question has 


only nine arms, though it has five plates to the pelvis, five costals, and 


five scapulars ; in this instance one of the scapulars only has produced 


one arm, the other four having produced the usual number. Another 
of the monstrosities has eleven arms, though this also has only the nor- 


_ mal number of pelvic plates, costals, and scapulars; one of these last 


sends off three arms. Another has eleven arms, arising from an in- 
creased number of pelvic, costal, and scapular plates, one of the scapu- 
lars sending off only one arm, the remaining five sending off two each. 
Another specimen has twelve arms, arising from six pelvic plates, six 
costals, and six scapulars ; in this instance, though each scapular sends 
off two arms, one pair of pelvic plates, costals, and scapulars is uni- 
formly smaller than the other three pairs. Another individual, the last 
instance mentioned of monstrosities in the number of arms, has thirteen, 
which arise from six pelvic plates, six costals, and six scapulars, one of 
these latter sending off three arms. 

The author has observed two circumstances which induce him to be- 
lieve it probable that Miller might be correct in his surmise that the 


animals were soft when living ;—1, when two portions of vertebral co- 


rg 


116 EIGHTH REPORT—1838. 


lumns have been pressed together, each has taken a corresponding im- 
pression from the other; 2, the great variety in the form and promi- 
nence of the tubercles on the joints of the arms. In some instances 
these joints are nearly free from tubercles; different parts of the same 
individual vary in this respect: some have very prominent and accu- 
mulated tubercles; in others these tubercles are extremely irregular. 
This cannot be taken as positive proof of their having been soft, but 
may nevertheless be regarded as confirming Miller’s opinion. 


Notice of Microscopical Discoveries. By Professor EURENBERG, 


In this extemporaneous address the learned Professor stated, that he 
had the honour of exhibiting before the Section as much as he had 
been able to effect of his great work on microscopic forms of life,—a 
work which, he observed, he should never complete, as the subject was 
inexhaustible, but that he should continue to extend it, as far as oppor- 
tunity would allow. After explaining many of the subjects represented 
in the engravings, he submitted to the inspection of the members pre- 
sent a bottle of the material, collected in considerable quantity in the 
vicinity of Lake Lettnaggsjon, in Sweden, to which the inhabitants of 
the district give the name of Bergmehl, or mountain meal. This earth, 
which resembles fine flour, has long been celebrated for its nutritious 
qualities, and was found, on examination, to be entirely composed of 
the shells of microscopic animalcules. The Professor also explained 
some circumstances to be observed in studying the interior structure 
of microscopic animalcula. 


Mr. Trevelyan exhibited a young living specimen from Rome, of the 
Coluber natriz of Italian authors, but evidently differing from the En- 
glish species so called; also a specimen in spirits of Polyodon foliwm 
of North America, a small collection of Neapolitan insects, and speci- 
mens, gathered by him in the island of Elba in 1837, of an Urtica, pro- 
bably an undescribed species. 


BOTANY. 


On the Production of Vanilla in Europe. By Professor Morren, 
of Liege. 

The Professor commenced by stating, that some difficulty at present 
existed in determining the species from which the vanilla of commerce 
was produced, but the Vanilla planifolia would produce it. This plant 
does not naturally produce odoriferous fruit ; but Mons. Morren had 
succeeded in obtaining, for two years running, fruits as large and odo- 
riferous as those of commerce. The author remarked, that the culti- 
vation of this plant might be now attempted in our intertropical colo- 
nies, with the application of the principles of modern botanical science, 


—~ 


TRANSACTIONS OF THE SECTIONS. 117 


and that this substance might be obtained at a much lower price than 
at present. The author thought the cultivation-of the vanilla plant 
could not take place in the British isles. In order to obtain good fruit, 
the plant should be allowed to grow five or six years; the fruit is not 
in proportion to the flowers; and the older, the larger, and the more 
branches the plant possessed, the better is its fruit. Exposure to the 
sun is not necessary for the maturation of the fruit; shade, heat, and 
humidity being the three conditions necessary for the flowers. The 
stigma of the plant is supplied with a peculiar appendage, which covers 
over the stigmatic surface in the form of a veil, and this requires to be 
lifted up before the artificial impregnation of the plant can take place. 
The author went into several particulars necessary to be attended to for 
the successful cultivation of the plant. 


On the Botany of the Channel Islands. By Cuarves C. BABincron, 
MA, PLS., §e. 


In this communication the author mentioned the discovery of the 
following eight plants in these islands in addition to those noticed at 
the Liverpool Meeting, namely, 


Ranunculus ophioglossifolius, Ononis reclinata, 
Orchis laxiflora, Potamogeion plantagineus, 
Linaria pelisseriana, Carex puncetata, 


Myriophylium alterniflorum, and Polygala oxyptera. 
He said that twenty species existed in the islands which had not as yet 
been noticed in Britain, and announced his intention of publishing an 
outline of their Flora in a few months. 


On the Genera Pinus and Abies. By Capt. J.C. Coox, RN. 


The author commenced by stating, that not less than seventy species 
of Pinus and Abies had been lately introduced into this country. The 
distribution of these throughout the world he divided into five groups: 
—l. Those of Old America, which included the United States, the 
Mississippi and Canada, with Labrador. 2. Those growing between 
the Pacific and Atlantic Oceans, in the district known by the name of 
the Rocky Mountains, and which might appropriately be called the 
“Douglas Group.” 3. The uplands of Mexico. 4. The Himalaya 
Mountains. 5. Europe. The first group contains about twenty spe- 
cies, none of which can be said to produce more than second-rate 
timber. They are fine trees in their native forests, but degenerate in 


Europe. 2. The “Douglas Group.” Of these there are about fifteen 
' Species, possessing all the qualifications for good timber, at the same 


time that they are evergreens, and grow quickly; and from the pre- 
sent condition of the young plants in England, the most sanguine an- 
ticipations of their successful culture in this country may be enter- 
tained. At present, however, little positive information had been ob- 


tained with regard to this group. 3. The species from Mexico are at 


118 EIGHTH REPORT—1838. 


present few in number; and too little information about them is pos- 
sessed to warrant any conjectures as to their worth. 4. Those in the 
Himalaya range are also few, and for the most part little known. Some 
of them may probably become naturalized in this country. The Adbzes 
Webbiana is a gigantic tree, but has not perfectly stood the last winter. 
Abies Morinda stood the winter very well. Both species are propagated 
by cuttings. 5. The European series is the most valuable. In this group 
the quality of the species is, as nearly as possible, in a direct ratio to 
the ability of the tree to resist cold; all the best species being found 
in an extreme northern latitude, or in an equivalent situation on moun- 
tains in the south ; no valuable species at all being found on the 
shores of the Mediterranean or the Baltic. The highest place in the 
European series is assigned to the Pinus cembra and P. uncinata, both 
of which grow in their respective Alpine and Pyrenean forests, above 
the P. sylvestris, or Scotch fir, and both excel it in the quality of the 
timber. The Pinus sylvestris is next, and its range is from the Arctic 
circle to the Sierra da Guadarama, in Spain. The next tree in the 
series may be considered P. Laricio, which grows in the mountains of 
Corsica, at rather a higher elevation, and in lat. 43°, and does not de- 
scend to the level of the Mediterranean. With this, both in latitude 
and elevation, is associated P. Hispanica, although in most respects it 
differs from other pines. Its range is from 39° to 43° N. lat., at the 
foot of the highest Pyrenees. These two species form about a middle 
zone in the European pinal vegetation, and their timber is found to 
occupy about a middle rank in quality, being superior to those below, 
and inferior to those above it in its range. The next species is Pinus 
pinaster, whose northern habitat is the Sierra da Guadarama, and 
ranges immediately under Pinus sylvestris; it is not so good a tree 
as might be supposed from its range, as it grows in sultry valleys and 
situations unfavourable for the production of timber. The Pinus pinea 
(Stone pine) has a timber nearly allied to the P. pinaster, its most 
northern habitat being in Old Castile, where it occurs in great quan- 
tity; and although it reaches a medium altitude, it is, like the last, 
found growing on sultry flats, as those of Andalusia, &c. The last of 
this series is the Pinus Halepensis, of which three varieties are known, 
which clothe the shores of the Mediterranean, on both sides, through- 
out its whole extent. 

The species of Abies do not admit of the same extended observation, 
the series being less in number and extent.. The European species are 
certainly inferior to those of Pinus. The A. excelsa is the hardiest, and 
resists a damp soil probably better than Pinus sylvestris. The A. pec- 
tinata is found much further south than the last, which extends no fur- 
ther than Savoy, whilst this is found in the Pyrenees and Navarre, and 
a variety has been observed in Cephalonia; and no doubt great use 
could be made of it in our own culture. The larch, although in some 
respects an anomaly in the genus, follows the same rules. Its southern 
site is the highest part of the Apennines in Piedmont, and its northward 
range is very great, but is never found at a low elevation. The Pinus 
austriaca probably belongs to this group, but the author knows little of 


TRANSACTIONS OF THE SECTIONS. 119 


it at present ; as also Pinus tawrica, which grows in the Crimea. ‘The 
cultivation of the hardier and more valuable species of these genera 
was strongly recommended from the results of the experiments of the 
Duke of Athol, who had found that timber of sufficiently good quality 
for the ordinary consumption of the navy might be grown at 1-140th 
the expense of oak, taking into consideration the rental of the land, 
and the ground occupied, besides the vast value given to the land by the 
fertilizing properties of the larch. The author estimated that 100,000 
acres of waste, taken from the Grampian hills, for the growth of larch, 
would, in two generations, not only supply all the ordinary wants of 
the country, but enable us to export the timber. In the west and 
south of England the Pinus Laricio and P. Hispanica would proba- 
bly succeed best ; the cedar of Lebanon might also be tried in these 
districts. He also recommended the larch to be cultivated by the 
proprietors of cold clay land in the north of England, as a means of 
improving the land by the deposition of its spicule, the trees being 
kept open for the admission of sheep for fifteen or twenty years, when 
the trees being gradually thinned, open woodland would be formed, 
the soil of which would be good. No other species of tree should be 
mixed, as the larch is recommended merely as a fructifier or amelior- 
ator of the soil. 


On Lycopodium Lepidophyllum. By G. B. Sowrrsy, F.L.S. 


Upon instituting a comparison between specimens in his posses- 
sion and the description and figures of Hooker, in his Jcones Planta- 
rum, t. 162, 163, Mr. Sowerby found them to agree so nearly that he 
has no doubt these specimens belong to Lycopodium lepidophyllum : but 
there are some points of difference. 

The first point of difference is in the disposition of the stalks, as 
Hooker calls them, or rather of the stalk as it appears in Mr. Sowerby’s 
plant; for Hooker says of his Lycop. lepidophyllum, “ caulibus plurimis, 
cespitosis, stellatim dispositis;’ whereas in Mr. Sowerby’s plant the 
stalk is spiral and very much branched. 

The next point of difference, and this must indeed be regarded as a 
very trifling one, is in the form of the stipules, which Hooker describes 
as “folio subsimilibus;” whereas in the specimens and in Hooker's 
figure they appear to be more pointed than the leaves. 

The third and last point of difference is in the form of the fructifying 
_ spikes, which Hooker describes in his plant as “ acute triquetris ;” while 
in Mr. Sowerby’s plant they are four-sided and acute-edged. 

Hooker says, “ This plant in South America has long enjoyed such a 
celebrity, from its remarkable hygrometric property, that specimens 
form an article of commerce between Mexico and Peru. Like the 
Anastatica Hierochuntica, or famous Rose of Jericho, in a dried state, 
the stems and branches are incurved, so that the whole plant forms an 
elastic ball ; on being moistened, the stems and branches spread out ho- 
rizontally, and this experiment may be repeatedly performed.” 


4 


120 EIGHTH REPORT—1838. 


One of Mr. Sowerby’s specimens was presented to him by Mr. 
Cuming, who gave an equal weight in gold for the specimen which he 
furnished to Sir W. Jackson Hooker. 


On Vegetable Monstrosities. By the Rev. W. Hixcxs. 


The author made some introductory remarks on the importance of 
the study of monstrosities, and concluded by a distribution of them 
into five classes:—1. Cases of coherence and adherence of parts not 
usually united, or of separation of those which are ordinarily connected. 
2. Anomalies depending on the comparative development of parts of 
one circle. 3. Anomalous transformations of organs. 4. Monstrous 
exuberances of growth, by which the number of parts is altered, inde- 
pendently of transformation, the number of circles of parts is increased, 
or the axis irregularly extended. 5. Anomalous abortions or suppres- 
sions of parts usually present in the species. Among the monstrosities 
produced belonging to the first class, were a specimen of Convallaria 
multiflora, in which the two lowermost leaves cohered by their edges 
into a sort of bag, which considerably obstructed the growth of the 
stem; a specimen of Yulipa Gesnertana, in which the leaf on the 
stem, folding round it, had cohered by its edges, so as completely to 
inclose the flower-bud, which, as it enlarged, carried up the upper part 
of the leaf, like the calyptra of a moss, or the calyx of Escholzia, and 
some adherent flowers, of which a specimen of Salpiglossis straminea 
was remarkable for the complete union of two flowers, so as to have 
but one calyx and corolla each, with a double number of parts. In 
the third class, a specimen was exhibited of Campanula rapunculus, 
with the bell-shaped corolla transformed into five additional stamens ; 
and one of Lilium longiflorum, with the stamens partially transformed 
into pistils, a stigma being produced at the extremity of each, whilst 
an imperfect anther was borne lower on the filament. Various other 
examples were produced in the several classes, which cannot be parti- 
cularly noticed. 


An Account of an Inosculation observed in two Trees. By Mr. 
WALLACE. 


MEDICAL SCIENCE. 


Observations on Plague and Quarantine, made during a residence in the 
East. By Dr. Bowrinc. 


The opinions and practices of the people of eastern regions much 
exposed to the ravages of the plague were narrated by Dr. Bowring, 
who drew from his observations the conclusion that plague was not 


TRANSACTIONS OF THE SECTIONS. 121 


contagious, and that quarantine laws were of no avail in checking its 
progress. 

The following information was communicated to Dr. Bowring, by a 
physician of long experience, in answer to a series of direct queries. 
The plague is indigenous in Egypt, never entirely absent, never im- 
ported ; it frequently occurs spontaneously, and cordons afford no se- 
curity against its diffusion. While contact very frequently does not 
produce it, and it is not occasioned by linen which has been exposed 
to the infection; the most cautious often suffer from it. Free ventila- 
tion is effective in checking the disease, and when a number of per- 
sons exposed to its influence remove from the infected spot, the mor- 
tality amongst them becomes much diminished. 


On the Origin and subsequent Development of the Human Teeth. By 
Mr. Goopsir. 


The author has observed dentition commence by the formation of 
what he denominates the primitive dental groove, on the floor of which 
the rudiments of the pulps of the milk teeth appear as globular or co- 
nical papille ; septa afterwards pass from the outer to the inner side of 
the groove, between the papillz, and thus each of the latter becomes 
situated in an open-mouthed follicle, which is the primitive condition of 
the future sac. After the formation of the milk follicles, the lips of the 
groove still remain prominent ; and when in this condition Mr. Goodsir 
denominates it the secondary groove. The rudiments of the ten anterior 
permanent teeth appear as little depressions in the secondary groove, 
internal to the mouths of the milk follicles. The papille of the milk 
teeth now begin to be moulded into the form of pulps, a change which 
is synchronous with the closure of the mouths of the follicles by two or 
more lamin, which agree in number, shape, and position with the cut- 
ting edges and tubercles of the future teeth. The lips and walls of the 
secondary groove now adhere, except in the situations of the ten de- 
pressions for the permanent teeth, and for a small extent posteriorly on 
each side, where a portion of the primitive dental groove remains in 
its original condition. In this portion the papille and follicle of the 
first large molar tooth appear, and, after it closes over, the lips of the 
secondary groove above it adhere, but not the walls; so that there is 


in this situation a cavity which produces the sacs of the two posterior 


_ permanent molars. ‘The first large grinder may, therefore, be con- 


sidered in some measure a milk tooth. The author observes, that den- 
tition begins, and is always in advance, in the upper jaw, except in the 
case of the incisive teeth, which, although they appear first, are later 
in coming to perfection. This he explains by the tardy development 
of the lateral elements of the intermaxillary system. ‘The author di- 
vides dentition into three stages. The first is one with which the au- 
thor states anatomists have hitherto been unacquainted,—viz. the folli- 
cular. The second and third they are familiar with—the saccular and 
the eruptive. From his researches, he concludes that the human teeth 


a 


122 EIGHTH REPORT—1838. 


originate from mucous membrane, that the permanent teeth have no 
connexion with the deciduous set, and that the sac and pulps must be 
referred to the class of organs denominated bulbs. He anticipates the 
discovery of the follicular stage in the dentition of all animals, and if 
so, that it will explain the varying and complicated forms of the pulp 
and sacs. ; 


Experiments and Observations on the Cause of the Sounds of Respiration. 
By Dr. SpirTau. 


The object of this communication was to show that the theory of 
Laennec, in regard to the cause of the respiratory sounds,—viz. that 
all those known by the terms vesicular, bronchial, tracheal, as well as 
cavernous and amphoric respiratory murmurs, are caused by the fric- 
tion of the air against the parietes of the air cells, bronchial tubes, tra- 
chea, and of cavities of different dimensions,—has never been proved ; 
that the few experiments which have been advanced in support of 
it, are far from establishing the conclusions which have been deduced 
from them; and that it is highly probable that, according to the theory 
of M. Beau*, these sounds either owe their existence to, or are in part 
produced or modified by, the transmission or reverberation of a sound 
which takes place in the superior respiratory passages, and which has 
been termed by M. Beau the “guttural” respiratory sound. In sup- 
port of the first theory, it was observed, that the best and almost the 
only experiment was that of Magendie, in which air was blown into 
the lungs by means of a pair of bellows, and sounds, resembling 
the respiratory murmur, were perceived; from which M. Magendie 
drew the conclusion, that because air passed to and from the lungs 
during this experiment, as well as during respiration, therefore the re- 
spiratory sounds are produced by the friction of the air against the pa- 
rietes of the bronchial tubes and air cells of the lungs. It was stated 
that the similarity between the sound produced by a pair of bellows 
and the guttural sound was admitted by Laennec; and that it was also 
observed that a similar sound could be produced by blowing air through 
almost any tube; differing in tone and degree according to the diame- 
ter or shape of the opening in the tube, the force with which the air 
is made to issue from it, and the nature of the materials of which it is 
composed. The experiments of M. Beau, in support of his particular 
theory, it was noticed, were open to objections, and did not seem to 
bear out very clearly the conclusions at which he arrives; which may 
perhaps account for the neglect his view of the subject has met with. 
For the purpose of obviating these difficulties, and showing in a more 
distinct manner the probable truth of this theory, to a certain extent at 
least, several experiments were devised by Dr. Spittal. In these ex- 
periments xo stream of air was allowed to pass through those parts 
which were the subject of observation; they were only allowed to be- 
come, and remain, distended with air; while, at the same time, the 


* Archives Générales, Paris, 1834. 


| 
: 


TRANSACTIONS OF THE SECTIONS. 123 


sound produced by the issuing of the air from an air-condensing ap- 
paratus, or from the mouth,—which very nearly resembled that of the 
bellows, and the guttural respiratory sound,—was observed to have 
passed freely, in one experiment, throughout an artery of eighteen 
inches in length, and to be perceived very nearly, if not quite, as loud 
in this as in another artery connected with it, and through which a 
current of air passed. In another experiment, in which the lungs of 
a lamb were used, sounds analogous to the tracheal, bronchial, and 
vesicular respiratory murmurs were distinctly perceived, although no 
current of air passed along the air tubes or cells; and in the case of 
a bladder attached to one of the great bifurcations of the trachea, 
a sound louder than that in the bronchial tubes was perceived, when 
the former was contracted to about an inch and a half or two inches 
in diameter; feebler when larger, and assuming, as its size was in- 
creased, a gentle, shrill, ringing, amphoric character. Dr. Spittal’s 
experiments were not advanced to prove that the guttural sound, or 
that which takes place in the superior respiratory passages, is the only 
source of the respiratory murmurs ; but to show that in all probability 
it exerts a considerable influence, if not in producing, at least in modi- 
fying, the different respiratory sounds, known as the vesicular, bron- 
chial, tracheal, cavernous, and amphoric respiratory murmurs, all of 
which have hitherto been explained according to the views of Laennec. 


On the Medicinal and Poisonous Properties of some of the Iodides. By 
, Dr. A. T. THomson. 


____The principal preparation whose action was detailed was the iodide 
_ ofarsenic. Different modes of preparation were pointed out, the cha- 
_ racters of the substance described, and specimens exhibited. The ac- 
- tion of this medicine in very minute doses, namely, from one-eighth to 
_ one-third of a grain, was stated to have proved peculiarly serviceable 
in lepra vulgaris, and chronic impetigo. A case of numerous tumours 
resembling carcinoma, dispersed under the skin, especially that over the 
mamme and in the axille, was found to yield to its continued action, 
and it was found equally successful in a more decided case of incipient 
carcinoma. Its action as a poison when given in an overdose was mi- 
_ nutely detailed in a series of experiments on dogs; the effects being 
very similar to those of arsenious acid. Coloured drawings of the 
morbid effects of this substance on the alimentary canal were exhibited. 
When injected into a vein, its effect was to destroy life, by destroying 
the irritability of the heart. 


> 


: On the Placental Soufie. By Dr. Apams. 


The author detailed some remarkable stethoscopic phenomena occa- 
sionally heard in connexion with placental souffle. 


124 EIGHTH REPORT—1838. 


Experimental Investigation into the Functions of the Eighth Pair of 
Nerves. By Dr. J. Ret. 


This communication was a continuation of the paper which the au- 
thor laid before the last meeting of the Association, and was chiefly 
confined to the functions of the gastric and pulmonary branches of the 
nervus vagus. 

From a great number of experiments upon the effects of division of 
the nervus vagus, it was observed that no dyspnoea was induced, if a 
sufficient quantity of air reached the lungs, and that the only constant 
and invariable effect of division of both vagi nerves was a great dimi- 
nution in the frequency of the respiratory movements. Though the 
nervus vagus is, however, the principal exciter of the respiratory move- 
ments, it is not the sole nerve which transmits to the medulla oblon- 
gata the impressions which excite the movements of respiration ; for in 
several experiments performed to ascertain this point, the respiratory 
movements continued (though much diminished in frequency) after 
the removal of the hemispheres of the cerebrum and the lobes of the 
cerebellum, and the division of the vagi and recurrent nerves. Dr. Reid 
believes that all the morbid changes observed in the lungs after death 
are to be explained by the effects of the diminished frequency of re- 
spiration. 

Several experiments were related to prove that digestion is not neces- 
sarily arrested after division of the vagi. These appeared satisfactory 
to Drs. Alison, Knox, and others who witnessed them. 

Experiments were related to prove that narcotic poisons produce 
their deleterious effects as rapidly when injected into the stomach after 
the division of the vagi as when these nerves are left entire. 

Experir.ents were brought forward to show that division of the vagi 
nerves previous to the introduction of a poisonous dose of arsenic into 
the system, does not arrest the usual mucous and watery secretions 
from the inner surface of the stomach and intestines. 

The results of a great number of observations were stated to prove 
that the contraction of the pupil, and the half-closed state of the eye- 
lids, which accompany section of the vagi in those animals in which 
the sympathetic is intimately conjoined with the vagus, are not the re- 
sult of the inflammation of the conjunctiva, but are independent of this 
circumstance. 


On the Beneficial Effects of Mercurial Action rapidly induced, more espe- 
cially in certain forms of Neuralgic Disease. By T. M. GREENHOw, 
one of the Surgeons to the Newcastle Infirmary. 


The purpose of this paper is to show the greater safety and efficiency, 
in many forms of disease, of introducing into the system such quanti- 
ties of calomel combined with opium, in repeated doses, as will secure 
the early production of the specific action of this medicine, as evinced 
by tenderness of the gums. 


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TRANSACTIONS OF THE SECTIONS. 125 


The author maintains that in various diseases, and more especially in 
severe neuralgic complaints, characterised by acute paroxysms of suf- 
fering of a periodic character, the efficacy of this method of employing 
mercury is found strikingly beneficial. 

Two cases of this description of disease were adduced by the author 


in proof of the correctness of his views. 


On the Functions of the Rete Mucosum and Pigmentum Nigrum, in the 
Dark Races of Mankind. By R. M. Grover. 


The paper of Sir Everard Home, published in the Philosophical 
Transactions for 1821, is the first attempt to investigate the subject ex- 
perimentally.. This author attributed the power of resisting the solar 
heat, manifested by the dark races, to a property possessed by dark 
surfaces of destroying the scorching and blistering effects of the solar 
rays on the skin. ‘Thus, according to him, were a black and a white 
skin exposed to the same degree of solar heat, the former should rise 
to the higher temperature, yet inflame the least. 

Mr. Glover endeavoured to prove, that the experiments of Sir Eve- 
rard Home are incorrect ; and that a black surface does not only rise to 
a higher temperature than a white one under the sun’s rays, but also 
scorches and blisters the skin in a greater degree. He further attempts 
to show experimentally that the scorching and blistering effects of white 
and black surfaces are precisely in the ratio of their powers of absorb- 
ing heat, a conclusion which is entirely opposed to the opinion of Sir 
Everard Home, who supposed that the rays of luminous caloric can 
blister the skin in a degree greater than what is accounted for by the 
quantity of heat contained in them. 

But although the skin of the black may absorb more heat than the 
skin of the white man, and although we are unable to explain the su- 
perior tolerance of heat by the possessor of the former in the mode 
adopted by Sir Everard Home, yet it is established that the organiza- 
tion of the inhabitant of the tropic, and especially of the negro, is pe- 
culiarly fitted to enable him to perspire freely on the application to him 
of the stimulus of heat ; while in the adaptation of his system to respond 
to this stimulus, and in the cooling effects of perspiration, which are 
shown by many experiments, must be sought the mode in which he is 
protected from the heat. 

The dark-coloured skin, the author is also of opinion, must radiate 
at night very freely ; this agrees with the well-known fact that negroes 
are exceedingly chilly in the nights of the tropics. 


Remarks on the Skull of Eugene Aram. By Dr. Incuts. 


In this communication the author endeavoured first to substantiate 
the fact that the skull produced was really taken from the body of Eu- 


- 


126 EIGHTH REPORT—1838. 


gene Aram ; secondly, that the development of the mental faculties, 
as indicated by the skull, corresponded remarkably with the character 
of Aram as recorded in history. 


On the Chemical Analysis of the Liquor Amnii. -By Dr. G. O. ReEs, 
F.G.S., &c. 


The author related his experiments on four specimens of the fluid 
procured from different individuals, all drawn off at 74 months of utero- 
gestation. The specific gravities varied from 1:0070 to 1:0086, the 
proportion of solid contents being much the same in each specimen: 
the solid ingredients varied, however, in relative proportion. Urea was 
found in all the specimens, the other ingredients being albumen, fatty 
matter, lactates, alkaline chloride, traces of sulphate, carbonate, and 
phosphate of lime, with oxide of iron. 


On Mr. Farr’s Law of Recovery and Mortality in Cholera. By Ropert 
D. Tuomson, M.D. 


The principal facts elicited are the following: 

1. The probability of recovery can be determined at every stage of 
disease by a simple tabular construction. 

2. The mean future duration can be determined at any given point. 

3. The rate of mortality, deduced day by day, shows that the fatality 
increases up to a given point, then becomes stationary, and afterwards 
decreases, according to a determined law. The rate of mortality attains 
its maximum at different periods in different diseases: in cholera it is 
at its maximum in twenty-two hours (eighteen to twenty-four hours) ; 
in small-pox in ten to fifteen days; in phthisis pulmonalis in six to nine 
months. When the disease has attained its acme and begins to decline, 
the rate of mortality on any day being given, the rate of mortality on 
any future day can be calculated, and vice versd. In cholera the rate 
of mortality declines nearly 12 per cent. daily, from the 4th to the 30th 
day: in its course the diagram describes a regular curve, which will 
represent in space what takes place in time. The rate of decrease va- 
ries in small-pox, but the variation is regulated by a certain law. 

4. The mortality no doubt increases according to a determined rate ; 
but in cholera it attains its maximum so rapidly, that the law of in- 
crease cannot yet be determined. The rate must be determined at four 
or five equal periods in succession before the law of its changes can be 
ascertained: this has not yet been done in any disease. 

5. The rate of recovery, like the rate of mortality, follows a pre- 
scribed rule: it increases according to a determined law, which has to 
a certain extent been determined in cholera and small-pox. 

For the purpose of this investigation, the cases of each disease should 
be recorded in the following form: 


TRANSACTIONS OF THE SECTIONS. 127 


CHOLERA EPIDEMICA. 


Age. | Date of Attack.| Date of Termination. Duration. 


——— 


1837. 
Edward Evans | 30 | June 21. | Died, June 21. 5 hours. 


Sarah Mills ...| 25 | June 22. | Recovered, June 26. | 4 days. 


Care should be taken to fix distinctly the time of invasion and the 
time of recovery, whether it imply the time when the patient can first 
digest food, or resume his ordinary occupation. The time of death is 
easily determined. The cases of small-pox and cholera comprehend all 
the diseases to which they give rise, or which follow in the same unin- 
terrupted series of morbid phenomena. The nature of the consecutive 
diseases should be recorded. The author is anxious to impress strongly 
upon every practitioner the utility of this simple registry of diseases, fol- 
lowing them from the beginning to the end of their course. The results 
already obtained prove that the harvest will be rich: they show the ad- 
vantage too of extended observations, carried on by numerous obser- 
vers, on a uniform plan. No one person could have observed 900 cases 
of cholera, and the law could not have been deduced from a small num- 
ber of observations. ; 

Several practical inferences are suggested by this investigation. 

1. It demonstrates the important fact, that pathological phenomena 
are as regular in their course as physical phenomena observed in inor- 
ganic matter; and that the instruments of physical investigation are 
applicable to medicine: for, after due allowance has been made for 
errors of observation and the limited number of cases, it will be found 
that the facts can be as exactly expressed by formulz, as any facts in 
the province of natural philosophy. 

2. A new field will be opened to the mathematician, and many inter- 
esting problems will arise for solution when accurate observations have 
been collected. If the abstract sciences are every day descending to 
practical applications, the empirical arts are also rapidly rising into the 
region of knowledge. 


On Sleep, and an Apparatus for promoting Artificial Respiration. By 
Joun Dauztet, M.D. 


In an essay on sleep drawn up in 1833, which constitutes the first 
part of this communication, the author directed particular attention to 
the dependence of this state on the feeling of fatigue in the muscles of 
respiration. The effects which follow this feeling are, diminished ac- 
tion of the organs and function of respiration ; diminished action of the 
organs and function of circulation; diminished supply of arterial blood 
in a given time to the brain; and, finally, sleep as an immediate conse- 
quence of the latter condition, In the subsequent part of the paper, 


128 EIGHTH REPORT—1838. 


Dr. Dalziel describes an apparatus for ascertaining the practicability 
of promoting artificial respiration, as a remedial means in certain states 
of the system. 

Some time ago it occurred to the author, that certain diseases, accom- 
panied with depression, might be mitigated, and other depressed states 
of the system effectually remedied, by immersing the limbs and trunk 
of the body in air which should be alternately rarefied and recon- 
densed, at the same time allowing the patient to inhale the air of the 
external atmosphere ; the rarefaction and recondensation to correspond 
with the motions of inspiration and expiration respectively. By this 
means, it was expected the function of respiration might be directly sup- 
ported and the general system invigorated. Inspiration being assumed 
to be the more laborious part of the process of respiration, and expira- 
tion to require little or no effort, it is the former part of the process that 
in depressing affections requires assistance. 

The degree of assistance which might in these cases be afforded, could, 
Dr. Dalziel supposed, be tested by experiments on persons in health, 
with apparatus of very simple construction. That which he made use 
of consisted of an air-tight box, large enough to contain the person to 
be experimented on (the head and neck excepted,) in a sitting posture, 
and a pair of circular bellows inside, which were used as a forcing air- 
pump. The bellows were worked from without by a piston rod, and 
the air which at every stroke they discharged was prevented by a valve 
from returning. In the side of the box were two small convex windows; 
one for the admission of light, the other for allowing an attendant to 
inspect the surface of the body during the experiment. 

When, by this apparatus, the pressure of the air was, to a certain extent, 
removed from the parietes of the chest, the feelings of exertion and re- 
pose attending respectively on inspiration and expiration were completely 
interchanged. The comparatively heavy air of the external atmosphere, 
which the person breathed, rushed along the air-passages and distended 
the chest without effort. There was a prevailing disposition to inspire. 
When the respiratory muscles were relaxed, the chest remained perma- 
nently distended, and a sensation of fulness of this cavity was distinctly 
experienced. Expiration on the other hand became difficult and labo- 
rious. The feeling in the chest attendant on the effort was analogous 
to that which is experienced in ordinary circumstances during inspira- 
tion, while supporting with the hands a heavy weight upon the breast, 
and attempting to elevate it. The voice in the mean time became so 
weak as to be almost inaudible. 

In order to produce the results above-stated, the air contained in the 
box was rarefied by abstraction of about one-nineteenth of its volume. 

Dr. Dalziel suggested the application of this apparatus in all diseases 
and affections of the system in which the functions of respiration and 
circulation require to be roused or supported. 

A model of more refined apparatus to perform the same effects, and 
several testimonials respecting the period of the invention, (1832,) were 
presented to the Section. 


TRANSACTIONS OF THE SECTIONS, 129 


On an Improved Acoustic Instrument. By Dr. Yr..oxy, F.RS. 


This communication was illustrated by a model of the instrument 
which Dr. Yelloly proposed for the purpose of assisting in cases of 
partial deafness. Allusion was made to the very defective nature of our 
__ present instruments, both as to utility and conveniency, and the import- 
_ ance of appointing some experimental investigation on the subject *. 


_ On the Action of various Substances on the Animal Economy, when 
4 injected into the Veins. By J. BuaKe. 


The author described a number of experiments with various sub- 
stances, and their effect on the vascular system, as measured by an in- 
strument which he termed a Hemadynameter, formed by a glass tube, - 
bent at an angle. One limb of this tube being attached to a scale, 
allows of measuring the height to which a column of mercury is raised 
by the action of the current of blood in the artery, into which the ex- 
tremity of the other branch is introduced. The substances introduced, 
in solution, into the veins, were divided into three classes according to 
their effects. In the first were those which produced death, by directly 
acting on the contractility of the heart, amongst which were nitrate of 
potassa, arseniate of potassa, sub-carbonate of soda, biniodide of arsenic, 
oxalic acid, and solution of galls; all these acted locally on the heart, 
and agreed in effecting a change in the colour of the blood, turning it 
black, probably by forming definite combinations with its constituents. 
A remarkable difference was observable in the effects produced by the 
same substances when absorbed from the stomach. In the second class 
_ were those substances which acted directly on the nervous system ; 
such were strychnia, hydrocyanic acid, and conia, And in the third 
were those producing death by affecting the capillary circulation ; such 
__ were tobacco, euphorbium, and digitalis. The last two classes of sub- 
_ stances did not produce any change on the composition of the blood. 
_ Several other substances were experimented with, not falling under 
_ the above classes, such as morphia and cantharides, the effects of 
Which were the same, and nitric acid: when the latter was injected 
into the vein, the column of mercury in the instrument fell from seven 
inches to one ; and after death, the right side of the heart was distended 
with solid blood. 


Se 


On an Improved Stethoscope. By A.B. Granvitie, MD. 


By this invention the patient may be examined without the necessity 

of his rising, and the necessity of having the practitioner’s head im- 

_ mediately parallel to the part examined is avoided. ‘These advantages 
are effected by the addition of a half ball-and-socket joint attached to 


* A recommendation to this effect was adopted by the General Committee. 
VOL. vit. 1838. K 


130 EIGHTH REPORT—1838. 


the ear-piece, which of course becomes moveable to a greater or less 
angle with the cylinder, as circumstances may require. 


Mr. Baird detailed a case of successful excision of the elbow joint. 
The patient was presented to the Section, and considerable motion was 
shown to exist in the joint; so much so, as to enable him to pursue his 
ordinary occupation in a glass manufactory. 


ee 


On Fractures. By T. M. Greennow. 


In illustration of this communication a model of a new sling fracture 
bed was introduced, applicable to every fracture in the lower extre- 
mity, but peculiarly adapted to the treatment of compound fractures 
of the femur. The following advantages were attainable by this ap- 
paratus :—Ist, Ease of position; 2nd, Easy and gradual extension by 
means of a screw at the termination, beyond the heel of the patient, 
whose action was connected with the ancle joint and instep; 3rd, Fa- 
cility of examining and dressing the limb in cases of compound frac- 
ture, without disturbing the fractured ends; 4th, The freedom of slight 
motion enjoyed in such a way as to be of no injury to the process of 
reparation. Mr. Greenhow detailed some interesting cases treated with 
this apparatus, demonstrating its peculiar advantages. 


Case of Anthracosis in a Lead Miner. By Dr. CRawrorp. 


The attention of the profession was first drawn to the subject of an- 
thracosis, or black infiltration of the lungs, in 1831, by the late Dr. 
James C. Gregory, and subsequently other cases have been published 
in the Edinburgh Medical and Surgical Journal. 

Dr. William Thomson, of Edinburgh, has also published a paper, in 
the London Medico-Chirurgical Transactions for 1836, on black ex- 
pectoration and black matter on the lungs. 

The subjects of all the cases made public have been either coal- 
miners or moulders in iron work, whose occupations have seemed to 
give countenance to the opinion that the disease originated either from 
the inhalation of coal-dust, gun-powder smoke, lamp smoke, choke 
damp, or the impure air of mines, consisting of a mixture of carbonic 
acid gas and the atmospheric air. In some of these cases there was, 
during life, dark-coloured expectoration with evidence of serious orga- 
nic disease of the lungs, e. g. phthisis; in others, there was bronchites, 
without expectoration of this dark matter; in a third class there were 
bronchites and emphyseura of the lungs, likewise without the dark- 
coloured matter; and in the fourth and last class there was found, after 
death, the black matter, no symptom nor sign of chest affection of any 
kind having been present during life, 


TRANSACTIONS OF THE SECTIONS. 131 


The author presented a short report of a case which disproved the 
opinion that this deposit is found only in coal miners and moulders in 
iron work. The individual was William Ritson, et. 77, many years 
inmate of the Tynemouth Union Workhouse. He had been employed 
from an early period of life as a lead miner, continuing at the employ- 
ment till within ten or twelve years of his death. During the middle 
period of his life he had been at sea for five years. 


On the Amount of Air required for Respiration. By Dr. D.B. Retv. 


From a very extensive series of experiments made upon the respira- 
tion of upwards of a hundred individuals, who placed themselves suc- 
cessively in an apparatus for this purpose; from trials made upon greater 
numbers yarying from 3 to 234, in apartments specially constructed 
for the purpose ; and from observations made under his direction in the 
House of Commons every day that Parliament had met during the 
last two sessions; Dr. Reid contended that the amount of air usually 
allowed for respiration, in public buildings and private dwelling-houses, 
was far below the standard required for sustaining either the bodily or 
intellectual faculties in health and vigour. He remarked that great 
errors in estimates upon this point had arisen from a variety of causes ; 
more especially— 

1. From the extreme difficulty of calculating and regulating pre- 
cisely the supply of air in apartments constructed in the usual manner. 

2. From the supply of air having been determined hitherto not by 
precise experiments upon the person, but from calculations, which, 
from the state of science, are at present necessarily imperfect. 

3. From the amount of air required to sustain the functions of the 
skin, and to facilitate by gaseous diffusion the removal of the matter of 
insensible perspiration having been in a great measure overlooked. 

_ 4, From neglecting the influence which even an excessively minute 
quantity of some gaseous and volatile substances diffused through the 
atmosphere may exert in gradually undermining the system. 

Dr. Reid’s communication contained a variety of details in reference 

_ to the constitutional peculiarities of different individuals in respect to 

air, and he contended that they differed as much in this respect as in 

reference to food and drink, exercise, temperature, clothing, &c. 

? In adverting to the influence of heat, light, and electricity, he brought 

_ forward a number of instances showing that the effect of light upon 

_ the human constitution is as important in its action as in the power it 

is known to possess upon the vegetable kingdom, and referred more 

particularly to a case pointed out by Sir James Wylie, in one of the 
est barracks, where there were THREE cases of disease among the 
soldiers whose apartments looked to a dark and dull court, for onE 
among those who were necessarily exposed to a bright light, the tem- 
perature, food, clothing, and discipline, being precisely the same. 
In concluding, Dr. Reid contended, 1. That the supply of air should 
KZ 


ed 


+ 


Definer 


132 EIGHTH REPORT—1838. 


amount at least to eight or ten cubic feet per minute in an aimelgnere 
at ordinary temperatur es. 

2. That the amount of supply should inerease greatly with the 
temperature. In the House of Commons he had never given less than 
thirty cubic feet for each individual when very crowded, and on one 
occasion he had supplied sixty cubic feet for each member for three 
weeks successively. 

3. That the same attention should be paid to the moisture in the air 
as to the temperature, and that the hygrometer is as indispensable in 
providing a proper atmosphere as the thermometer and anemometer : 
5000 feet of moist surface were used at the House of Commons. 

4. That the air may be filtered from suspended impurities, and in 
many local situations others may be separated with extreme facility. 

5. That from the pernicious effects of minute quantities of impuri- 
ties acting for a long period, it is desirable in providing artificial light 
to exclude hermetically from every apartment all the products of com- 
bustion. 


On the Modus Operandi of Nitrate of Silver as a Caustic and Thera- 
peutic Agent. By Rozserr D. Toomson, M.D. 


When a solution of animal matter, (for example, a solution of what is 
usually termed albumen, obtained from the eggs of birds,) is added to 
a solution of nitrate of silver, white coagula are immediately preci- 
pitated resembling chloride of silver, but differing on closer inspec- 
tion, as under the microscope, considerably from the latter salt. When 
the precipitation is induced in considerable quantity, the upper portion 
of the deposit soon begins to turn darker coloured, and gradually as- 
sumes a brownish appearance. ‘The lower portion of the precipitate, 
however, still retains its original aspect with the addition of bands of 
dark matter, which traverse it in different directions. In addition to 
this we observe, that it becomes matted together and has a stringy 
consistence approaching to that observed in the incipient formation of 
the mucous membrane. Having added an excess of animal matter to 
the nitrate of silver solution, the author threw the precipitate on a filter 
and washed it repeatedly with distilled water. On testing the liquid 
with a solution of the animal matter no precipitation ensued, demon- 
strating that nitrate of silver in its original form no longer existed in 
the solution, but had been entirely removed, or at least its properties 
obscured, in consequence of the addition of the animal matter. To de- 
termine, however, whether any silver existed in the fluid, the latter was 


evaporated on the sand bath. The solution gradually became dark- — 


coloured, and the evaporating basin in which the experiment was made 
was coated at the upper surface of the fluid with a brown deposit. On 


the total evaporation of the solution, a brown glazed-looking matter — 
covered the bottom of the vessel, which, on exposure in the cold, gra- — 


dually absorbed moisture from the atmosphere, and was readily seraped 


TRANSACTIONS OF THE SECTIONS. 133 


off from the vessel in the form of a moist powder. These experiments 
show that there are two compounds of albumen and nitrate of silver, 
one of which is insoluble and the other soluble in water—the one being 
an acid and the other a basic compound. The author proceeded to 
state the result of his endeavours to ascertain the operation of nitrate 
of silver upon the animal economy. After numerous experiments 
upon the secretions of the mucous membranes of the cesophagus, 
stomach, &c., he found that precisely similar compounds are formed 
by these fiuids,—a circumstance which admits of ready explanation, if 
we consider these fluids as merely solutions of some modification of al- 
bumen. The same compounds are formed by bringing the nitrate of 
silver in contact with the cutis, which is generally considered to con- 
sist of gelatin, although it possesses most of the properties of albumen. 
Until, however, we know what albumen is and are acquainted more 
accurately with the nature of the causes which give rise to its modifi- 
cations, it will be in vain to attempt to assign any definite composition 
to these compounds ; we can only study their physical and chemical 
properties ; but this we can do most efficiently so as to render the facts 
of great importance in a therapeutic point of view. From the facts 
ascertained by the author in respect to the compounds of animal mat- 
ter and nitrate of silver, he has drawn the following conclusions :— 

1. That nitrate of silver acts as a caustic by combining with the ani- 
mal matter of the textures to which it is applied, probably in definite 
proportions. The compounds are partly soluble and partly insoluble in 
water, which renders them readily separable from the surface on which 
they are produced. Cauterization is, therefore, the removal of a por- 
tion of organized matter by chemical means. 

9. When nitrate of silver is taken into the stomach, chemical com- 
pounds of a similar nature are formed with solid matter dissolved in 
the secretions, and with the food contained in that organ. Hence, no 
nitrate of silver can ever reach the blood as nitrate of silver. 

3. The author pointed out the importance of studying the action of 
these compounds upon the constitution, and the fallacy of supposing 
that nitrate of silver can act per se upon the animal ceconomy. 


Observations upon Uterine Hemorrhage and Practical Hints on the 
best mode of arresting it. By R. Torsock. 


After noticing the circumstances attending uterine hemorrhage, the 
difficulty of sometimes restraining it, and the remedial means devised 
and recommended by the best writers, Mr. Torbock described an in- 
strument which he had invented and employed with success in cases of 
_ this nature. The instrument for this purpose is simply an India-rub- 
ber bag, so prepared that it may be greatly distended. When introduced 
into the vagina (or even into the uterus if necessary), it will, by its 
perfect adaptation, preclude the possibility of blood escaping, and torm 
_an effectual plug. Cases were detailed in support of this statement. 


alt 


On the oceurrence of Crystals in the Human Intestines. By 
O. B. Bettincuam, M.D. 


The author prefaced a description of the circumstances attending a 
case of this nature by a short review of the previous observations of 
Ehrenberg, who found microscopical crystals in the meconium; Schon- 
bein, who found small crystals in the intestinal discharges of typhus 
patients, and imagined they might be considered as a diagnostic of ty- 
phus ; and Miller, who detected them in persons that died of various 
disorders. 

Dr. Bellingham’s case was that of an individual (male), et. about 40, 
who died of pleuropneumonia and gastritis, in St. Vincent’s Hospital, 
Dublin, after being admitted only a few days. On examining the in- 
testinal canal, the contents of the colon were found to be very fluid, 
and of a lighter colour than usual. Suspended in the contents were 
numerous small hard parts, which proved to be crystals, somewhat less 
than the third of a line in length. Their colour was white (superfici- 

.ally yellowish), their form a slender four-sided prism, terminated by 
four-sided pyramids. On analysis, Dr. Apjohn found them to be com- 
posed of phosphate of ammonia and magnesia, or the triple phosphate. 
They were found only in the colon. 

The author remarks, that the ammoniaco-magnesian phosphate found 
in the urinary bladder is usually formed in short three-sided prisms, 
terminated by three or six-sided pyramids. 

The composition of the crystals found by Schonbein was very differ- 
ent from these, consisting chiefly of phosphate of lime, some sulphate 
of lime, and a salt of soda, and presented the appearance of rhombs or 
rhombic prisms. In one case, however, he found four-sided prisms, and 
Dr. Bellingham remarks, that the triple phosphate has been frequently 
noticed in the intestinal secretions of quadrupeds, as by Fourcroy, 
Vauquelin, and Marcet. 


134 EIGHTH REPORT—1838. 


On Abscess of the Lungs. By Tuomas Barnes, M.D. 


Regarding the frequency of this disease, a difference appears between 
the statements of ancient and modern medical authorities, the former 
affirming it to be of common occurrence, the latter uniformly asserting 
its rarity. The formation of an abscess in the lung being now con- 
sidered so very rare, Dr. Barnes thought a brief account of two cases 
which lately occurred to himself worthy the attention of the Meeting. 

The first case was of a gentleman 40 years of age; his disease ori- 
ginated in influenza (Feb. 1837). He was of a sound and healthy con- 
stitution, without any predisposition to phthisis or pulmonary disease, 
and in Aug. 1838 he had recovered ; but the symptoms he had suffered 
left no doubt in the minds of Dr. Barnes, Dr. Headlam, and Mr. Ed- 
monson of the true nature of the disease. ' 

The second case is that of a stone-mason, aged 45, whose illness 
commenced on the 28th March, 1838, and was attributed by himself to 


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: 
a 


TRANSACTIONS OF THE SECTIONS. 135 


working in warm rooms, and throwing off his clothes when heated. 
His disease proved fatal on the 18th May. 

The symptoms of treatment of each case, and the post mortem exa- 
mination of the latter by Dr. Elliot, were fully described. 


On’the Structure of Teeth, and the resemblance of Ivory to Bone, as 
illustrated by microscopical examination of the Teeth of Man, and of 
various existing and extinct Animals. By Professor Owrn, F.RS. 


Mr. Owen commenced by showing, that he had availed himself of 
the advantage afforded by the British Association, viz. that in the com- 
munications brought before a sectional committee, a fuller and more 
detailed retrospect of the progressive steps which have led to any re- 
markable discovery, is not only permissible, but peculiarly congenial to 
its general views and objects; and he therefore entered into a full de- 
tail of the recent investigations, especially those of Purkinje, Muller, 
and Retzius, on the intimate structure of the teeth, and particularly 
dwelt on the discoveries of the latter author, as regarded the structure 
of the human tooth. After describing the mode of arrangement of the 
particles of the earthy salts, which characterizes true bone, Professor 
Owen proceeded to state, that until a very recent period the analogy 
of tooth to bone was supposed to extend no further than related to the 
chemical composition of the hardening material, while the arrangement 
of this earthy constituent, as well as its mode of deposition during the 
growth of the entire tooth, were considered to be wholly different from 
that of bone, and to agree with the mode of growth of hair, and other 
so-called extra-vascular parts, with which teeth in general closely cor- 
respond in their vital properties. He observed, that the supposed 
proofs of the laminated structure of teeth, derived from the appear- 
ances presented by the teeth of growing animals, fed alternately with 
madder and ordinary food, and by those which often occur during 
the progress of decomposition of certain teeth, which are then resolved 
into a series of concentric or superimposed laminz, were equally ap- 
plicable to true bone, and were quite unavailable in illustrating the 
point under consideration; and that the appearances presented by the 
superficies of vertical sections of teeth, viewed with the naked eye or a 
low magnifying power, were due, not to the intervals of separate and 
superimposed lamelle, but to the different refractions of light, caused 
by the parallel undulations or alternations of structure of minute tubes 
proceeding in a contrary direction to the supposed lamelle. This ap- 
parent lamellated structure, however, is not constant, nor equally plain 
in different teeth ; on the contrary, the fractured surface, or the polished 
section of the human and many other teeth, presents a silky or irides- 
cent lustre, which has attracted the attention of several anatomists. Pro- 
fessor Owen observed, that Malpighi, in whose works may be detected 
the germs of several important anatomical truths, which have subse- 
quently been matured and established, conceived that the teeth were 
composed of minute fibres reticularly interwoven ; and Leewenhoek, in 


136 EIGHTH REPORT—1838. 


1683, had discovered that the apparent fibres of tooth were, in reality, 
minute tubes. The tubular structure of ivory was rediscovered by 
Purkinje and Fraenkel, in 1835, and the disposition of the tubes is ac- 
curately described and figured by them in the different kinds of human 
teeth. In these descriptions the tubes are spoken of according to their 
prima facie appearance as fibres, but their true nature is explained in dif- 
ferent passages of the work*. Purkinje and Fraenkel also added to 
Dental Anatomy several new and interesting facts relating tothe structure 
of the enamel, pointing out more especially the form and characteristic 
transverse striz of the component crystals: and, lastly, they determined 
the true osseous nature of that distinct layer of substance which had 
been previously known to surround the fang in the teeth of man, and 
which they once observed to be continued upon the enamel of a hu- 
man incisor. This observation, Mr. Owen proceeded to state, he had 
confirmed, and he exhibited several sections of the simple teeth of the 
Mammalia in which both the ivory and enamel were invested by a layer 
of osseous substance, identical in its structure with the cement which 
enters more abundantly into the composition of the compound teeth of 
the Herbivora. 

The interesting experiments of Professor Muller, on the nature and 
contents of the dental tubuli were then noticed; and, lastly, a con- 
densed analysis was given of the laborious and accurate microscopical 
observations of Professor Retzius, as related in the original Swedish 
memoir of that author on the structure of teeth. Besides confirming 
the fact, that the ivory or bony constituent of a human tooth consists of 
minute tubes lodged in a transparent medium, disposed in a radiated 
arrangement, with the lines proceeding in a direction perpendicular to 
the superficies of the tooth, Professor Retzius has more particularly 
observed and described the dichotomous branching of the primary 
tubes; the minuter ramuli sent off throughout the course of the main 
tubes into the clear interspaces ; the calcigerous cells with which those 
fine branches communicate; the terminal ramifications of the tubuli, and 
their anastomoses with each other, and with calcigerous cells at the 
superficies of the ivory or bony part of the tooth. Professor Owen also 
discussed the opinion advanced by Professor Retzius, as to the function 
of this elaborate contexture of branched and anastomosing tubes and 
cells, in conveying, by capillary attraction, a slow current of nutritive 
or preservative fluid, through the entire substance of the tooth ; which 
fluid might be derived either from the superficies of the pulp in the 
internal cavity of the tooth, or from the corpuscles or cells of the ex- 
ternal layer of cortical substance or ca@mentum,—with the tubes ra- 
diating from which corpuscles, the fine terminal tubes of the ivory 
anastomose. Professor Owen concluded the critical portion of his com- 
munication, by explaining the views entertained by Professor Retzius 
on the analogy subsisting between tooth and bone, which analogy he 
then proceeded to illustrate by his own observations on the structure 
of recent and fossil teeth. 


*® De Penitiori Dentium Humanorum Structura Observationes. Vratislavie, 1835. 


* 
4 


oF De 


TRANSACTIONS OF THE SECTIONS. 137 


With respect to the component structures of a tooth, Professor Owen 
commenced by observing, that in addition to those usually described 
and admitted, there were other substances entering into the composi- 
tion of teeth, and presenting microscopic characters equally distinct 
both from ivory, enamel, and cement, and from true bone, and as easily 
recognisable. 

One of these substances was characterized by being traversed through- 
out by numerous coarse canals, filled with a highly vascular medulla or 
pulp, sometimes anastomosing reticularly,—sometimes diverging, and 
frequently branching,—sometimes disposed nearly parallel with one an- 
other, and presenting more or fewer dichotomous divisions. The canals 
in many cases are surrounded by concentric lamellz, and thus resemble 
very closely the Haversian canals of true bone; but the calcigerous 
tubes which everywhere radiate from them are relatively much larger. 
The highly-organized tooth-substance just described differs from true 
osseous substance, and from the camentum, in the absence of the 
Purkingian corpuscles or cells. This structure is exemplified in the 
teeth of many fishes and of some of the Edentate Mammalia. 

Another component substance of tooth more closely resembles true 
bone and cement, inasmuch as the Purkingian cells are abundantly 
scattered through it; it differs, however, in the greater number and 
close parallel arrangement of the medullary canals. This structure is 
exhibited in the teeth of the Megatherium, Mylodon, and other extinct 
Edentata. 

Mr. Owen then proceeded to describe the modifications of the above- 
mentioned dental substances in the teeth of different classes of the ver- 
tebrate animals, of which the following examples are selected. 

Ist. Teeth of Fishes—With respect to this class, although the low- 
est of the vertebrate series, their teeth present in general the most 
highly organized condition, approximating most closely to the vascular 
character of true bone, and being in many species fixed by anchylosis 
or continuity of substance with the bones supporting them. 

It was in the teeth of fishes that, in recent times, the tubular struc- 
ture had been first recognised. Cuvier*, e. g- describes them as pre- 
senting three different structures, of which one kind (es composées) 
are formed of an infinity of tubes, all united and terminated by a com- 
mon covering of enamel; of this kind he instances the tesselated teeth 
(dents en forme de pavé), as those of Rays. 

Dr. Born also describes what he terms the “ fibrous teeth of fishes,” 
as being composed of hollow fibres}, and he compares these hollow 
fibres, or tubes, to those which enter into the composition of the teeth 
of the Orycteropus, &c. 

The tubes here spoken of, as well as those mentioned by Cuvier, are 
sufficiently large to be distinguished by the naked eye; they do not, 


_ however, form the constituent texture of the teeth instanced, but only 


the coarser part of that texture. They contain a vascular medulla, 


* Lecons d’Anat. Comp. 2d ed. tom. iii. p. 209. 
7 Heusinger’s Zeitschrift, B.i. p.184, “ Die Faserzihne bestehen in ihrem Innern 
aus hohlen Fasern,” &c. 


et 


138 EIGHTH REPORT—1838. 


and are the centres from which the true calcigerous tubes radiate, and 
they are, therefore, analogous to the simple pulp-canal of the human 
incisor, which, with its radiating microscopic ealcigerous tubes, may be 
compared to a single medullary canal with its corresponding microsco- 
pie radiating tubes in the Rays, Orycteropus, &e. 

Myliobatis —A longitudinal section of a single“dental plate, viewed 
by a low power of an inch focus, exhibits at its base a coarse network 
of large irregular canals, filled with a vascular medullary pulp. From 
this network smaller medullary canals proceed in a slightly-diverging 
course, subdividing dichotomously with interspaces equal to six or eight 
of their own diameters. In a transverse section of the tooth, seen under 
the same power, the area of the medullary canals is seen to present ge- 
nerally an elliptical form, from which radiating calcigerous tubes are 
faintly perceptible. Each canal and its series of tubes is surrounded 
by a line of generally an hexagonal form, and which constitutes the 
boundary between contiguous canals and tubes, the whole tooth being 
thus composed of an aggregate of simple elongated, commonly six-sided 
prismatic teeth, placed vertically to the grinding surface. A section 
through the roots of the tooth shows that these parts are occupied by a 
network of irregular canals, which anastomose by arched branches 
with the network of the contiguous root, and these with the network 
of coarser tubes which occupy the basis of the tooth for an extent ex- 
ceeding the length of the root itself. 

With a higher power, ;1,th inch focus, the calcigerous tubes are seen 
to radiate in all directions from the medullary canals, and are sent off 
throughout the whole course of the canal. The tubes are short, wavy, 
richly arborescent, and form numerous anastomoses with each other. 
The transverse sections of the tooth show that the area of each medul- 
lary canal has been filled up or diminished by the deposition of a 
series of concentric lamelle. 

The ramification of the tubes in this tooth presents the same general 
character as those of Acrodus, but they are shorter, and each group in 
the transverse section is separated from the contiguous one by the re- 
gular boundary lines above-mentioned, which distinguish the teeth of 
the Myliobatis from those of the Acrodus, Psammodus, Cestracion, or 
any of the shark tribe. The tooth of the Oryeteropus is that which 
has the nearest resemblance to the tooth of the Myliobatis. 

Acrodus nobilis—The crushing teeth of this extinct genus are com- 
posed of two substances, viz. a thin external almost colourless layer, 
which represents the enamel, and an amber-coloured coarser ivory 
composing the body of the tooth, and continuous with and passing into 
the coarse cellular bony basis and support of the tooth. Microscopic 
sections of this tooth afford the most beautiful appearances, and, per- 
haps, the most instructive illustration of the relation of ivory to bone. 
The body of the tooth consists of groups of beautifully branched and 
irregularly wavy medullary canals imbedded in a clear matrix. These 
canals are surrounded by concentric strata, and closely resemble the 
canals of Havers in true bone. The calcigerous tubes, which radiate 
from the medullary canals, have a graceful undulatory course and are 


TRANSACTIONS OF THE SECTIONS. 139 


much branched; but towards the periphery of the tooth, the ramifiea 
tubes are all directed, as in true ivory, at right angles to the superfi- 
cies, and thus constitute a regular layer of calcigerous tubes, disposed 
so as to offer the greatest resistance to pressure. This layer is equal 
in thickness to about one-fifteenth part of the vertical diameter of the 
thickest part of the tooth. 

The finest or terminal branches of this peripheral layer of tubes, I 
have traced in various places into what at first sight appears to be the 
enamel. Undera magnifying power of 400 diameters, however, this out- 
ermost layer is seen to be composed of extremely minute tubes, >p5 th of 
a line in diameter’; they are branched like the coarser tubes of the body of 
the tooth; irregularly wavy in their course; having a general tendency 
to an arrangement at right angles to the superficies, but inextricably 
interwoven, and connected anastomotically together, so as to require a 
strong light to penetrate even the thinnest section, and render their 
structure and arrangement visible. The continuation of these finer 
superficial tubes, with the coarser tubes of the body of the tooth, is best 
observed by changing the focus, which brings the transitional tubes at 
different depths in the section into view. Insome parts of the section, 
a medullary or Haversian canal is displayed longitudinally ; and the 
parallel lines of the surrounding concentric strata on each side are ex- 
hibited. The canal maintains a general uniform diameter, but slightly 
dilates where it divides or sends off a cross branch to communicate 
with the adjoining canals. These canals commence from the large cells 
of the bone of the base, and pass into the substance of the tooth to- 
wards its periphery; communicate by transverse canals, but. all ulti- 
mately terminate in bundles of the wavy ramified calcigerous tubes of 
the body of the tooth. I conclude that the coarser canals were occu- 
pied by a vascular pulp in the living animal, and that the fine terminal 
tubes were the seat of the salts of lime. The silex occupying the lon- 
gitudinal canals and coarser tubes, has received a dark stain, probably 
from the colouring matter of the vascular pulp,—but the finer tubes, 
from the want of this difference of colour, are in many parts obscurely 
visible, if at all. They are discernible in some situations crossing the 
concentric lamelle at right angles to the central canal. The chief dif- 
ference between the appearance presented by the Haversian canals of 
the tooth of Acrodus, and those in true bone, is in the absence of the 
cells or corpuscles. These are apparent only at the base of the tooth— 
irregular in size and form, very minute, and appearing like simple gra- 
nules without radiating lines. The character of the main or coarser 
canals and calcigerous tubes of the ivory of the tooth of Acrodus, re- 
poses on their undulating course, their rapid diminution and branching, 


and the moderately acute angles at which the branches are given off, 


except at the circumference of the tooth, where they run nearly parallel 
to each other. In other parts they closely resemble the branching of 
trees. The line of demarcation between the coarser and finer ivory is 
formed by a series of small cells of a similar granular appearance to 
those at the base, in which many of the finer branches of the coarse 
ivory terminate, and from which the minute tubes of the enamel-like 


140 EIGHTH REPORT—1838. 


ivory commence. The superficies of the tooth is slightly. punctated, 
but the depressions do not correspond with the mouths of tubes, but 
with the interspaces of whole groups of the coarser tubes. 

Psammodus.—A transverse section of the tooth of this genus pre- 
sents the appearance, under a moderate magnifying power, as if it were 
composed of close-set coarse tubes, the arez of which were thus ex- 

osed. Such a scction, viewed with a power of 400 diameters, shows 
that these tubes are surrounded by concentric lamella, exactly as the 
Haversian canals; and that these lamelle, and the clear interspace, 
which is generally equal to the thickness of the lamella, are permeated 
by minute irregularly disposed tubes, which anastomose in the clear 
interspace, and open into extremely minute cells, scattered in the same 
part. A longitudinal section of the same tooth shows the whole course 
of the canals; they run nearly perpendicularly to the convex super- 
ficies of the tooth, and, consequently, incline outwards at the sides of 
the section. They lie nearly parallel with each other, with interspaces 
equal to from 6 to 8 times their own diameter, and branch dichoto- 
mously once or twice in their course. Each canal is surrounded by 
concentric layers of a dark colour, encroaching upon one-third of the 
interspace, which thus presents two dark streaks and one intermediate 
right line: the whole of these interspaces is perforated by the irregular 
wavy, branched, anastomosing calcigerous tubes. The terminations of 
the canals near the periphery of the tooth are slightly dilated, and give 
off in every direction calcigerous tubes corresponding to those in the 
interspace of the canals. The structure of the tooth of Psammodus 
differs from that of Acrodus in the greater number and more parallel 
course of the canals, their fewer branches, and want of anastomoses, 
and in the absence of a distinct external enamel-like layer of very fine 
tubes. 

Ptychodus latissimus.—The structure of this tooth has a close affinity 
to that of Psammodus: it is composed of Haversian canals and cal- 
cigerous tubes proceeding therefrom. The base of the tooth is com- 
posed of close-set and irregular canals, and is very opaque: the canals 
emerge from this part half-way to the grinding surface, to which they 
proceed perpendicularly. They differ from those of the Psammodus 
in being wider, more close-set, and more branched,—the branches 
being given off at more open angles, and the terminal ones being larger 
in proportion to the trunks. The papillose surface of the tooth is com- 
posed of the terminations of the inextricably interwoven fine calci- 
gerous tubes given off from the terminations of the canals. The inter- 
spaces of the canals are also occupied by the same minute anastomosing 
reticulate tube-work. Numerous minute calcigerous cells are also 
present in the interspaces. There is a clear substance coating the 
grinding surface of the tooth, in which neither tubes nor any definite 
structure could be detected, though, from analogy, such doubtless 
exist. The darker substance, forming the concentric lamella around 
the canals, occupies the same proportion of their interspace as in the 
Psammodus. 

Chimera—The tooth of this fish appears, when a section of it is 


TRANSACTIONS OF THE SECTIONS. 141 


viewed with the naked eye, to be composed of a close-set series of pa- 
rallel coarse tubes, dividing dichotomously, and united together here 
and there by short transverse arches with the convexity towards the 
grinding surface. The diameter of the interspaces of these canals is 
generally equal to between two and three diameters of their arez. 

Viewed by a higher power, the tubes are seen to be immediately 
surrounded by a clear amber-coloured substance, analogous to that 
which forms the concentric layers around the canals, which I have 
compared to those described by Havers in true bone. 

Under a power of 400, the large canals are seen to send off from 
every part of their course numerous minute tubes, generally at right 
angles, to the medullary canals; these tubes run irregularly, ramify, 
and anastomose in the interspaces of the medullary canals, and form a 
coarse matting or plexus of tubes, the number of which sometimes 
quite intercepts the light. 

In the teeth of the genus Lamna, a number of medullary canals are 
continued from the short and small pulp-cavity at the base of the tooth, 
which ramify and anastomose, so as to form a beautiful reticulate 
arrangement of tubes, very similar to a network of capillary vessels, 
throughout the whole substance of the tooth: they ultimately termi- 
nate in a flattened sinus, which seems to extend over the whole tooth 
at a very short distance from its superficies. The whole of. the super- 
ficial part of the tooth is occupied by minute calcigerous tubes, which 
proceed in a wavy course, generally at right angles to the external 
surface; they ramify, and their terminal branches anastomose, and 
many of them terminate in a stratum of calcigerous cells, situated be- 
tween the body of the tooth and what appears to be the outer stratum 
of enamel. In this stratum, however, there are evident traces of a 
series of much finer tubes, continued from the preceding layer of cells, 
which proves that this is not true enamel, but a fine kind of ivory, like 
that in the tooth of the sloth and megatherium. The coarse reticulate 
eanals in the body of the tooth are surrounded by concentric layers, 
traversed by the calcigerous tubes which are everywhere given off at 
right angles from the larger canals; these canals are occupied, in the 
recent fish, by a sanguineous medulla, closely resembling that which 
fills the medullary cells of the coarse bone, to which the base of the 
tooth is anchylosed, and with which cells the anastomosing reticulate 


_ eanals of the tooth are directly continuous. 


Carcharias Megalodon—'he calcigerous tubes at the superficies of 
this tooth are disposed in groups which, with an insufficient magnifying 
power, appear like single coarse tubes, but with a higher power, are 
seen to be composed of congeries of parallel tubes, apparently twisted 
together. ‘The interspaces are nearly equal to the diameter of these 
curious fasciculi: they are occupied by more seattered tubes, and by 
short oblique or transverse anastomosing branches. At one part of a 
section of this tooth, the peripheral coarse sinus or canal, which always 
runs parallel with the superficies, gave off an infinite number of minute 
tubes, which formed a plexus, (or plexiform stratum,) and from the 
outer part of this plexus, the tubes above described passed, at right 


142 EIGHTH REPORT—1838. 


angles, to the surface. In the longitudinal section of this tooth, the 
twisted appearance, above described, of the peripheral calcigerous tubes, 
was seen to be due to the number of side branches given off at an 
acute angle to the main tube. At the apex the tubes radiate, and sud- 
denly diverge to proceed transversely to the sides. In the bedy of the 
tooth the main canals are surrounded by concentric lamelle, traversed 
by radiating and anastomosing calcigerous tubes, which form a fine net- 
work in the interspaces. 

Dictyodus, a sphyrenoid genus——The body of the conical maxillary 
teeth of this fossil species presents a beautiful assemblage of medullary 
canals, having a general parallel course from the basis to the apex, divi- 
ding and subdividing as they approach the latter, with interspaces gene- 
rally equal to three or four of their own diameters, and anastomosing by 
short branches crossing the interspaces, and thus intercepting quadran- 
gular, sub-elliptical, pentagonal, or hexagonal spaces, elongated in the 
axis of the tooth, but becoming shorter as they approach the apex, 
which presents the appearance of a coarse irregular lace-work. The 
interior of some of the larger canals is occupied with a granular matter. 

I have been able to detect the fine calcigerous tubes only at the cir- 
cumference of the tooth radiating from the peripheral side of the su- 
perficial canal into the clear enamel-like coating of the tooth. ‘They 
immediately begin to ramify at acute angles. 

The larger canals are continued directly from the coarse medullary 
cells at the bony base of the tooth: the longitudinal ones are mostly 
larger than the transverse or oblique short anastomosing canals. This 
tooth resembles in general structure that of the Anarrhichas Lupus. 

The round pharyngeal teeth of the extinct genus Spherodus are 
anchylosed to a bone of a cellular structure. The body of the tooth 
consists of coarse tubes, which arise insensibly from the basis, where 
they have a dianieter of s4,,;th of an inch, and proceed directly and 
perpendicularly to the surface of the tooth. The characteristics of 
these tubes are, first, that they are so closely arranged together, that ~ 
only one-fourth of their own diameter intervenes between them at their 
origins. Secondly, they present the appearance of a closely-twisted 
bundle of smaller tubes, and begin immediately to give off short and 
somewhat coarse branches at very acute angles; these branches increase 
in number, and the trunks proportionally diminish, until they have 
traversed two-thirds of the vertical diameter of the tooth ; they resolve 
themselves into fasciculi of extremely minute twigs, which interlace 
together, and in many places dilate into, or communicate with, nu- 
merous minute calcigerous cells, and form so dense a layer as to inter- 
cept the light, excepting towards the circumference of the tooth, and 
consequently at the two extremities of the section, where only the 
structure above described is visible. Several small twigs pass beyond 
this plexus into the clear enamel-like outer layer of the tooth, in some 
parts of which traces are perceptible of a plexus of still more minute 
tubes, or strie, which gradually diminished until they escaped the 
highest magnifying power employed in this examination. 

Lepidotus—The pharyngeal teeth of some of the species of this 


; TRANSACTIONS OF THE SECTIONS. 143 


genus, e.g. Lepid. Fittoni, correspond so closely in size and form with 
those of the preceding genus, (Spherodus, ) as not to be distinguishable 
from them but by a comparison of their microscopie structure. They 
are composed of fasciculate tubes continued directly from the cells of 
the osseous base, radiating, with a direction vertical to the surface of 
the tooth, and giving off branches, at an acute angle, from their very 
commencement: thus far the general character of the texture of the 
tooth is the same; but the fine branches into which the fasciculate 
tubes resolve themselves, diverge at a much more open angle from the 
main trunk, are spread out more widely, have a more wavy course, and 
present the appearance of corn beaten down with heavy rain. These 
five terminal branches are inextricably interwoven, and present the ap- 
pearance of numerous anastomoses, but do not ferm so dense a structure 
as to intercept the light, as is the case in the teeth of Spherodus. 

Gyrodus.—In the pharyngeal teeth of this genus, the tendency to 
the structure of the dense ivory of the teeth of the higher vertebrata, 
which is obvious in the teeth of Spherodus and Lepidotus, is carried 
on to a close correspondence. The base of the tooth is excavated by 
a large and simple pulp-cavity, presenting a quadrate figure in a ver- 
tical section of the tooth; this cavity is immediately continuous with 
the large cells and reticulate canals of the bony base. The body of 
the tooth consists of close-set minute calcigerous tubes, having a dia- 
meter of 74,th of a line at their origin, radiating in a direct line, but 
with a minute and regularly undulating course, and a gradually dimi- 
nishing diameter to the superficies: the lateral tubes pass horizontally, 
those continued from the summit of the pulp-cavity vertically, to the 

_ grinding surface. They give off very regular, but extremely minute 
branches, which are lost in the clear and dense enamel-like superficial 
layer of the tooth. 

Barbel. Pharyngeal tooth.—In this tooth the structure character- 
istic of the ivory of the simple mammalian tooth is beautifully dis- 
played. The cavity of the pulp is single, elongated and narrow, and 
the tubes radiate to the surface of the tooth at right angles to that sur- 
face, and chiefly, therefore at right angles to the axis of the tooth. 
The tubes are minute and numerous, beautifully and regularly undu- 
lating, seldom dividing, and then dichotomously, each branch proceed- 
ing nearly in the direction of the trunk. A detached fossil pharyngeal 
tooth of this kind would be distinguishable from a mammalian carni- 
vorous tooth of similar form by the circumstance, that in the tooth of 
the fish the pulp-cavity beecmes directly continuous with the coarse cells 
and medullary canals of the bone with which it is anchylosed ; the base 

_ of the tooth is not diminished to a fang, and the calcigerous tubes are 
larger and more irregular the closer they are to the base of the tooth. 

The large conical carnivorous teeth of the extinct genera Holopty- 
ehus and Megalichthys present a similar grade of structure to that of 
the pharyngeal tooth above described. The whole body of the tooth is 
here composed of minute close-set calcigerous tubes, having a diameter 
of + 55th of a line in diameter, with interspaces of nearly twice that 
diameter, The calcigerous tubes have a minutely undulated course, 


q 


144 EIGHTH REPORT—1838. 


and pass in nearly a straight line from the internal to the external sur- 
face of the tooth: the pulp-cavity extends about half-way through the 
body of the tooth, and has a narrow elliptic transverse section; it be- 
comes gradually smaller at the base of the tooth, and there branches 
out into several processes, which are continued into the cylindrical 
processes of the dental substance, which are imbedded, like so many 
piles, in the coarse osseous texture of the jaw. It is this peculiar mode 
of fixation of the tooth to the jaw-bone that would serve at once to 
distinguish the tooth of Holoptychus from that of any saurian or mam- 
miferous species which it might resemble in external form. 

In not any of the teeth of fishes above described was there, an-ex- 
ternal covering of enamel, presenting the characteristic trausversely- 
striated prismatic crystalline structure which distinguishes the enamel 
of the higher Vertebrata. In all cases, where structure could: be de- 
tected in the dense exterior layer representing the enamel, it presented 
the organized tubular character, differing from the subjacent ivory 
only in the more minute size of the tubes. 

Of the teeth of reptiles, Prof. Owen described those of several genera, 
recent and fossil. In the Sharp-nosed Alligator ( Crocodilus acutus), 
the exposed part of the tooth is covered with true enamel, and that part 
which is lodged in the socket is coated with a layer of cementum. ‘The 
tubuli are very fine, not exceeding at the widest part ;,55th of a line. 
With a low magnifying power they appear to radiate in straight lines 
from the cavitas pulpi to the superficies of the tooth, proceeding at 
right angles to that surface: under a higher power, they are seen to 
be slightly undulating, and to have interspaces equal to five times their 
own diameters. The main tubes begin to divide soon after their origin, 
and the branches diverge from each other; these send off numerous 
finer ramuli, which are generally turned towards the root: these ter-~ 
minate or dilate, in many places, into calcigerous cells, which form 
numerous layers, generally arranged parallel with the contour of the 
cavity of the pulp, and most numerous at the circumference of the 
ivory. It is to these layers of calcigerous cells, and to the parallel cur- 
vatures of the tubes, that the apparent laminated structure is seen to 
be due, when sections of these teeth are examined with a low magnifying 
power. A thin membrane lines the cavity of the pulp of even the oldest 
teeth. ; 

The fossil teeth of the extinct Reptiles reveal an equally complicated 
structure. The fang of the fluted teeth of the Jchthyosaurus is covered 
with a thick layer of cementum, which fills the interstices of the 
grooves. The tubuli of the ivory-constituent are extremely minute ; 
they resemble in their arrangement and ramification those of the cro- 
codile, but the undulations are more numerous and more marked. 

In the Zgwanodon, the ivory is composed of close-set tubes, radiating 
in a wavy course from the cavitas pulpi to the superficies: each tube 
is also minutely undulating. They are coarser than those of the Ich- 
thyosaurus; and the ivory further differs in the presence of large me- 
dullary canals, which are seen here and there radiating from the cavity 
of the pulp, and traversing the dense ivory. Ress 


LE eae 


TRANSACTIONS OF THE SECTIONS. 145 


In the class Mammalia the teeth of the animals belonging to the 
order cailed Edentata by Cuvier, present the nearest resemblance to 
the vascular and organized structures above described in the teeth of 
cartilaginous fishes. The close resemblance, in this respect, between 
the teeth of Orycteropus and Mylobatis has already been alluded to, 
but their outward form and mode of attachment are widely different. 
The teeth of Orycteropus present the form either of a simple cylinder, 
or of two joined laterally together. In these, as in the tesselated teeth 
of the Rays, Cuvier had recognised a tubular structure ; but the tubes 

- described by that great anatomist were merely the medullary or pulp- 
canals which run parallel with the axis of the tooth, at regular distances 
from each other. These visible medullary canals, which are widest at 
the base of the tooth, diminish at first rapidly, and afterwards very 
gradually in diameter, and some of them divide dichotomously in their 
course from the base to the grinding-surface of the tooth. Throughout 
their course they send off at right angles and from every part of their 
circumference the true calcigerous dental tubes. These tubes, at their 
origin are 73,th of a line in diameter, but quickly diminish, as they pro- 
ceed in a wavy course to the interspace which divides them from the 

contiguous medullary canals and their systems of calcigerous tubes : the 
tubes give off numerous branches, which form, near the boundary space, 

a moss-like reticulation of extremely fine tubes. Nearly the whole ex- 

tent of the medullary canal is occupied with a vascular pulp, and its 
parietes near the base is likewise surrounded with a thin vascular cap- 
sule ; the whole tooth is in fact composed of a closely-packed congeries 

__ of slender prismatic elongated miniature simple teeth, each of which is 

j provided with its pulp and capsule, its medullary cavity, and its radiated 

series of calcigerous tubes. The capsule of each component prismatic 
oth becomes ossified at a little distance from the base of the tooth. 

__A transverse section of the whole compound tooth above this part pre- 

_ sents a series of hexagonal, pentagonal, or tetragonal groups of cal- 

_ cigerous tubes radiating from an elliptical space occupied by a vaseular 

pulp, and separated from each other by a thin boundary line of bone 
or cementum, characterized by the presence of Purkingian corpuscles. 

a The vascular pulp, likewise, becomes ossified near the grinding-surface 

of the tooth, and consequently a transverse section taken near this part 
_ presents the centres of the radiation of the calcigerous tubes filled up 
_ with bone or cementum. 

_ Bradypus didactylus—The substance in the tooth of this species 

_ which corresponds to the true ivory forms only a very thin layer, situ- 

ated near the superficies of the tooth ; the central yellowish substance 

_ of the tooth presents a number of coarse canals, about one-tenth of a 
line in diameter ; these radiate in a beautiful manner from the upper 
_ part of the pulp-cavity, those in the middle proceeding parallel to the 
- axis of the tooth, those at the circumference curving outwards. These 
_ canals are unequal, presenting partial dilatations, which, however, are 

_ sometimes, though rarely, discernible in the tubuli of human teeth; 

they give off numerous tortuous branches of different sizes, and these 
open into very distinct calcigerous cells scattered about the interspaces 

| VOL. vil. 1838. L 


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146 EIGHTH REPORT—1838. 


of the coarser canals. The fine crust of ivory above mentioned is 
formed by minute tubes directly continued from the finer ramifications 
of the large canals of the central substance, and terminated in plexus of 
still finer tubes, which at length escape the highest magnifying powers. 
The fang, or inserted part of the tooth, of the sloth is coated with a 
_ayer of erusta petrosa, which is characterized by large canals and abun- 
dant Purkingian corpuscles. There is no enamel in the composition of 
these teeth or of those of any of the existing Edentata. 
Megatherium.—Microscopiec examinations of the structure of the 
teoth of this extinct mammifer have undeceived me with respect to its 
conformation ; the thin dense layer between the crusta petrosa and- the 
internal substance composing the body of the tooth is not enamel, but 
a layer of ivory composed, like the dense ivory of the teeth of other 
Mammalia, of minute tubes having a parallel course at right angles to 
the surface, and minutely undulating in that course, and corresponding 
with the thin cylinder of true ivory in the tooth of the sloth. The cen- 
tral part of the body of the tooth consists of a coarser ivory, much 
resembling the teeth of Psammodus or Myliobatis, among fishes. It is 
traversed by large medullary canals parallel to each other and to the 
finer ivory tubes, having angular interspaces equal to one and a half 
diameter of their own area, and generally anastomosing in pairs by a 
loop whose convexity is close to the origin of the fine ivory tubes, as if 
each pair so joined was composed of one reflected canal. Some, how- 
ever, are continued across the fine ivory, and anastomose with the corre- 
sponding canals of the cementum; the interspaces of the coarse ivory 
tubes appear at first view granular, but they are principally occupied 
by reticular branches given off from the canals: some of these anasto- 
mosing branches are seen coming off from the concavity of the loops, 
and retrograding. Numerous minute cells are scattered about the ter- 
minal loops of the medullary canals of the coarser ivory. The origin 
of the fine ivory tubes is from the convexity of the peripheral loops of 
the above medullary canals. The ivory tubes are separated by inter- 
spaces equal to one and a half their own diameter; they divide and 
subdivide, growing smaller and more wavy towards the periphery or 
camentum ; here their terminal branches assume a bent direction, and 
form anastomoses, dilate into small cells, and many are clearly seen to 
become continuous with the radiating fibres or tubes of the corpuscles 
of the contiguous cementum. The cement is traversed by large canals 
running, like the canals of the coarse ivory, parallel to each other and 
to the course of the fine ivory tubes, with interspaces of about five times 
their own diameter, occasionally, but rarely, dividing dichotomously,— 
in which case the branches usually anastomose and form loops with the 
convexities towards and close to the outer layer of fine calcigerous 
cells, in which the fine ivory tubes terminate. The cement differs 
from the coarse ivory in the fewer number of canals, and more espe- 
cially by the presence of the bone corpuscles or radiated cells in the 
interspaces of the canals. The irregular tortuous fine tubes forming a 
network in the interspaces, and especially those proceeding from the 
convexities of the loops, are much more distinct than the correspond- 


TRANSACTIONS OF THE SECTIONS. 147 


ing tubes in the coarse ivory. The primary branches of the canals go 
off generally at right angles. In a few places I have distinctly seen 
the large canals of the cementum traversing the substance of the fine 
ivory to anastomose with those of the central coarse ivory. 

We have thus, then, in the tooth of the Megatherium, an unequivo- 

_ cal example of a course of nourishment of the teeth distinct from and 

_ superadded to that which proceeds from the surface of the pulp and 
the cavity of the fang in which it is lodged, viz. by a direct communi- 
cation between the vascular canals of the external organized cementum 
and the tubuli of the ivory. etzius observes of the human tooth, that 
«the fine tubes of the cementum enter into immediate communications 

_ with the cells and tubes of the ivory, so that this part can obtain from 
without the requisite humours after the central pulp has almost ceased 
to exist.” In the Megatherium, however, those anastomoses have not 
to perform a vicarious office, since the pulp maintains its full size and 
functional activity during the whole period of the animal’s existence. 

It relates to the higher organized condition, and doubtless to the higher 
vitality of the entire grinder in that extinct species. 

The views entertained by Cuvier of the affinity of Megatherium to 
Bradypus, derive full confirmation from the microscopic investigation 
of its teeth. It needs but to compare the preceding description with 
that published by Retzius of the structure of the teeth of the Armadillo, 
to perceive how much more closely the Megathere resembles the Sloth 
in the structure of its teeth. The Megatherium has ten teeth in the 
upper jaw, five on each side ; differing slightly in form and size, but all 

_ presenting the same characteristic vascular structure as above described. 
_ Thestructure of the coarse central ivory may be compared with that of 
_ which the entire tooth of the Orycteropus is composed, with these dif- 
_ ferences,—first, that the parallel medullary canals and their systems of 
_ ealcigerous tubes are not separated from their neighbours by a layer of 
¥ cementum, and, secondly, that the medullary canals anastomose at their 
_ peripheral extremities. 
_ Toxodon.—The teeth of this extinct animal have an external but in- 
complete investment of enamel, which is deficient for a small extent at 
_ the anterior and posterior surfaces of the tooth; but these parts, as 
_ well as the enamel, are covered with a thin exterior layer of cementum. 
§ The body of the tooth is composed throughout of compact ivory, con- 
_ sisting of minute wavy calcigerous tubes, ;35th of a line in diameter at 
_ their origin, which radiate in directions vertical to the superficies of the 
_ tooth, or of the inflected fold of enamel, from the central pulp-cavity. 
In the discontinuity of the enamel surrounding the ivory of the tooth, 
_the Toxodon differs from all known Pachyderms, and exhibits an ap- 
proach to the Rodentia and Edentata. 
: In the Leopard, the tubuli of the canine teeth are chiefly remarkable 
: for the number of their ramifications, and the beautiful curvatures of 
the same. In the Mole, the main tubes are remarkable for their width 
and shortness; they are as large at their commencement as in the 
human tooth, but soon divide at their extremities into a number of 
smaller branches, which again subdivide, the terminal twigs anasto- 
L 2 


148 EIGHTH REPORT—1838. 


mosing and communicating with minute calcigerous cells immediately 
beneath the enamel. 

The teeth of those orders of Mammalia in which they present the 
usual structure of compact ivory, enamel, and ee@mentum, have been 
described in several genera with so much accuracy. by Professor Reézius, 
that there are few modifications or examples worthy of particular at- 
tention. 

In the simple teeth of the Marsupial animals, the external layer of 
cementum covering the enamelled crown is thicker in many of the 
species than is usually seen. The Phalangers, Koala, and Wombat, 
offer good examples of the superficial layer of cement on the exposed 
crown. It possesses the usual high degree of organization, and abounds 
in the Purkingian cells. 

In the incisors of the Orang-Utan, the main calcigerous tubes of the 
ivory, which radiate from the central cavity of the pulp, are somewhat 
larger than those of man; they present the same primary curvatures, 
but less numerous and less strongly-marked secondary undulations*. 
In the crown of the tooth of the Orang, the dental tubes are chiefly 
branched at their extremities, while towards the apex of the fang the 
main tubes are surrounded by exceedingly fine and close-set branches, 
which subdivide in their course. The nearer the crown, the larger are 
these branches; they are curved, with the concavity towards the pulp. 

In the summary of this series of observations which Professor Owen 
detailed, he observed, that in the human and similarly organized teeth, 
the analogy of ivory to bone, as to texture, was only seen in the ex- 
istence and intercommunication of the minute calcigerous tubes and 


were regarded as analogous to a single enlarged Haversian canal, when 
the cavity of the simple pulp would represent the medullary cavity of 


the canal; while the tubes, with the appearance of laminze occasioned © 


by their undulations, might be deemed equivalent to the concentric la- 
mellz and the calcigerous tubes, which, in bone, traverse these lamelle, 
and radiate from the Haversian canal. In the teeth of many of the 
lower animals, however, and especially that of the extinct Acrodus, 
amongst the cartilaginous fishes, the resemblance of the dental tissue 
to bone was extended to the existence of the characteristic Haversian 


canals in great numbers. The presence of these canals was explained — 


by the progress of the development of these bone-like teeth, as observed 
by Professor Owen in recent cartilaginous fishes. The large pulp, at 
the commencement of the formation of the tooth, had exercised its 
ordinary function in the secretion of a close-set series of calcigerous 


* The primary curvatures Professor Owen explained to be those which belong to 
the general course of the dental tube, and which are seen with a lower power; in 
man they resemble the curves of the Greek Zeta (Z). The secondary curves are mi- 
nute undulations in the whole course of the tube, requiring a high power for their 
perception, and affecting both the main trunks and their branches; these probably 
indicate and are due to the movements of the formative pulp during the deposition of 
the ivory. : 


% 


cells; but that there was no trace of medullary or Haversian canals, — 
with their characteristic concentric laminz, unless the entire tooth — 


TRANSACTIONS OF THE SECTIONS. 149 


tubes, having a general direction perpendicular to the surface of the 
tooth, and closely resembling true ivory. The pulp then, instead of 
continuing to form similar tubular ivory, by adding to the extremities 
of the previously formed tubes, became subdivided, or broken up into 
numerous processes, to which those forming the three fangs of a hu- 
man grinder are analogous. But each process here becomes the centre 
of an active formation of similar branched tubes, radiating in all di- 
rections from that centre, and anastomosing by their peripheral branches 
with those from contiguous centres, or communicating with interposed 
calcigerous cells. The cavities containing the above subdivisions of the 
pulp, like the Haversian canals containing the processes of medulla in 
true bone, have had their area diminished in like manner by the suc- 
cessive formation of a series of concentric lamella, traversed, as in 
true hone, by radiating and minutely ramified calcigerous tubes, com- 
municating with each other and with the minute cells in the inter- 
spaces. ‘The resemblance between the pulp canals of the teeth of 
Acrodus and of the medullary canals of bones, is further exemplified 
in the existence of lateral communications in teeth ; and in function as 
well as structure they may be regarded as being identical. 

With reference to the application of the tubular structure of the 
teeth to the explanation of their pathology, Professor Owen observed, 
that it was a new and fertile field, which would doubtless be replete 
with interesting results, and might suggest some good practical im- 
provements in dental surgery. Ordinary decay of the teeth com- 
menced, in the majority of instances, immediately beneath the enamel, 
in the fine ramifications of the peripheral extremities of the tubes, and 
proceeded in the direction of the main tubes, and, consequently, by 


the most direct route to the cavity of the pulp. The decayed sub- 


stance, in some instances, retains the characteristic tubular structure, 
which is also observable in the animal basis of healthy teeth after the 
artificial removal of the earthy salts. The soft condition of the de- 
cayed portion of a tooth is well known to all dentists; it depends upon 
the removal of the eartliy salts from the containing tubes and cells, in 
which process the decay of teeth essentially consists. The main ob- 
ject of the dentist, in reference to ordinary caries of the teeth, seems, 
therefore, to be, to detect those appearances in the enamel which in- 
dicate the commencement of decay—to break away the enamel, whose 
natural adhesion to the subjacent softened ivory will be found to be 
‘more or less diminished—to remove the softened portion of the ivory 
and fill up the cavity with incorrodible substance. Experience proves, 
what could not be intelligibly explained before the true structure of 
the dental substance was known, viz. that the progress of the decay is 
sometimes thus permanently arrested. Such cases sometimes exhibit 
a thin dense layer of ivory in contact with the stopping, apparently re- 
sulting from an exudation of the calcareous salts from the extremities 
of the tubes divided in the operation. 
In conclusion, Professor Owen passed in general review over the 
structures which he had described in detail. He particularly pointed 
out the important application of the microscopic examination of thin 


150 EIGHTH REPORT—1838. 


slices of fossil teeth to a determination of the natural family, or genus, 
to which such teeth had belonged, when other characters fail, or a 
complete tooth is unattainable. Finally, Mr. Owen remarked, that 
through the endless diversity which the microscopic texture of the 
teeth of different animals presented, the universal. law of the tubular 
structure could be unequivocally traced; and that the general tendency 
of the modifications observable in descending from man to the lower 
classes of the vertebrate animals, was a nearer approximation of the 
substance of the tooth to the vascular and organized texture of bone. 


MECHANICAL SCIENCE. 
On the Use of Wire Ropes in Deep Mines. By Count Aucustus 


BREUNNER. 


There had been introduced into the silver mines of the Hartz Moun- 
tains, about seven years ago, ropes composed of twisted iron wire, as a 
substitute for the flat ropes previously in use. Since that time they 
have been adopted throughout the mines of Hungary and most of those 
in the Austrian dominions, to the almost total exclusion of flat and 
round ropes made of hemp. ‘These iron ropes are of equal strength 
with a hempen rope of four times the weight. One has been in use 
upwards of two years without any perceptible wear, whereas a flat 
rope performing similar work would not have lasted much more than a 
single year. The diameter of the largest rope in ordinary use in the 
deepest mines of Austria is one inch and a half. This rope is com- 
posed of iron wires, each ¢éwo lines in diameter ; five of these are braided 
together into strands, and ¢hree of these strands are twisted tightly into 
arope. Great care is requisite in making the rope that the ends of 
the wires be set deep in the interior of the rope, and that no two ends 
meet near the same part. The strength of these ropes is little less than 
that of a solid iron bar of the same diameter. The usual weight lifted 
is 1000 lbs. The rope on leaving the shaft must be received on a cy- 
linder of not less than eight feet diameter, and be kept well coated with 
tar. There is a saving of about one-third of the power in one case 
mentioned, for four horses with a wire rope are doing the same work 
as six horses with a flat rope. It was suggested by Count Breunner, 
that the substitution of iron ropes for the flat ropes in our deep mines 
and coal-pits would be attended with the same, if not greater ad- 
vantages than have attended their introduction into the mines of the 
Austrian dominions. 


On the Timber Viaducts now in progress on the Newcastle and North 
Shields Railway. By B. Green. 


The object of this paper was to give a description and explanation 
of the principle of constructing timber bridges on a more durable, 


i 


q 


{ 


TRANSACTIONS OF THE SECTIONS. 151 


stronger, and cheaper principle than the timber framing heretofore 
used in this country. 

For this purpose the author exhibited models on a large scale of the 
peculiar ‘lamination’ of the timber in the arches, by which, along 
_ with other advantages, a decided advantage is gained in strength. 
With a model upon this principle for a bridge across the Tyne 
_ 120 feet span, experiments were made in the presence of part of the 
managing directors of the railway, and some scientific persons, which 
_ proved highly satisfactory; for a weight of 250 stone was placed 
upon it, without the slightest deflexion of the arch being perceptible. 
_ This, multiplied by 144, according to the scale of the model, gives 
$4,900 stone, or upwards of 218 tons, as the weight the arch of 120 feet 
would bear without being affected. A great surplus strength was 
_ therefore manifest, to cover all contingencies, and make allowances for 
the increased span and extra dimensions. 

_ The plans and elevations of two viaducts at Ouseburn and Willing- 
ton Dean were laid before the section. The former, at the eastern 
_ suburb of Newcastle, is 920 feet in length and 108 feet in height ; there 
__ are five arches, of 116 feet span each, and two stone arches, at each end, 
of 45 feet span each. These were introduced in order to prevent the 
_ mounds coming too close upon the very steep banks of the ravine. 
_ The latter bridge is 1150 feet long, and consists of seven arches, 120 
feet span each. The height up to the roadway is 82 feet. Stone 
_ arches were not requisite here, as the banks are of a more gradual 
slope. : 
__ The piers and abutments are of stone. Each arm is composed of 
three ribs, formed to the proportionate curve shown on the model. 
Every rib is put together with 3-inch deck deals, in lengths of from 
90 to 45 feet, and two of the deals in width. The first course is 
_ formed of two whole deals in width, and the next of one whole and two 
half deals ; and so on alternately until the whole rib is formed. Each 
_ rib consists of 15 deals in height or thickness, and the ends are butted 
_ one against the other, breaking joint, so that no two of the horizontal 
_ or radiating joints shall come together. The whole are connected with 
_ oak trenails or pins, each of which passes through three of the deals in 
_ thickness. Between every deal a layer of brown paper, dipped in boiling 
_ tar, is laid, to secure the joints from being affected by wet, and so as to 
_ make the timbers bed tightly one upon the other. The ends of each 
_ rib are inserted into large cast iron shoes or sockets, which are first fixed 
_ to the springing stones of the masonry, and secured with long iron bolts, 
_ four to each plate, run in with lead. The three ribs are connected 
_ together with diagonal braces and iron bolts. 
_ The spandrils, formed by the arches, being great, on account of the 
_ Span, the framing is made in proportionate strength. A beam 
_ 14 inches square is fixed about the middle of the spandril, inclining 
_ upwards to the crown of the arch; from which struts are carried, both 
_ above and below it. Those above are perpendicular to the longitudi- 
nal beams of the roadway, and those below are radiating to the centre 
‘ of the arch. 


152. EIGHTH REPORT—1838. 


The longitudinal beams under the roadway are 14 inches square ; 
and transverse joists, 3 feet 6 inches apart, and projecting about 2 feet 
on each side, are laid across to receive the 3-inch planking, which 
is covered with a composition to forma roadway. 

The rails for the locomotive engine and train ‘are raised above the 
planks about 8 inches, on longitudinal beams or sleepers of timber, 
about 12 inches by 6. A strong framed railing is then fixed along 
each side, the length of the bridge, and completes the structure. 

The spandril framing is connected and bound, both to the roadway 
and to the ribs, by means of iron bolts, straps, and keys, in the different 
situations shown on the model. One of the radiating struts in each 
spandril is carried on from the rib to the longitudinal beams, and con- 
nected thereto, and to the masonry, by bolts passing through and run 
down the piers about 8 feet. 

In this system of timber bridge building, the straight trussing in the 
main principle of support is dispensed with ; for the spandril framing 
must not be looked upon as such; it is merely a combination of wood- 
work, to convey the weight coming upon the roadway on to the sim- 
ple curved rib; and all timbers in a state of tension are avoided; for 
when a weight comes upon the roadway, the whole structure under- 
goes compression. 

Mr. Green has also applied this laminating principle to a more durable 
material, viz. iron, and he described the modifications which this appli- 
cation rendered necessary, and the advantages it offered. 


Outline of the Principles of the Oblique Arch. 
By Perer NIcHoLson. 


The oblique arch is an invention of comparatively recent date; but 
the general use of the locomotive engine rendering it urgent to pre- 
serve the most direct line for railways, has caused the general adoption 
of oblique bridges on all the lines of railway now in progress, and — 
it has become a matter of importance that the theory of their con- — 
struction should be fully understood. 

The principles of the oblique arch which the author proposes for 
the guidance of engineers, require that five of the faces of each stone 
be prepared in such a manner that four of them shall recede from _ 
the fifth ; and, when the stones are arranged in courses, the surfaces of 4 
the fifth face shall form one continued cylindric surface, which is the — 
intrados, and the other four surfaces shall form the beds and ends of 2 
the stones on which they join each other. In every course two of the q 

. 
a 


opposite surfaces of the first stone, two of the opposite surfaces of the 
second stone, and so on, shall form two continued surfaces throughout | 
the whole length of each course; and the edge of each of these con- 
tinued surfaces in the intrados shall be a spiral line. If a straight line ~ 
be drawn through any point in one of the spiral lines, perpendicular to 
the axis of the cylinder, the straight line shall coincide with that con- 
tinued surface which is a bed of that course, and the straight line thus 


, 


TRANSACTIONS OF THE SECTIONS. 153 


drawn shall be perpendicular to a plane which is a tangent to the 
curved surface of the cylinder at that point in the spiral line; there- 
fore the straight line thus drawn shall be perpendicular to another 
straight line which isa tangent to the spiral line at that point. 

When the intrados is developed, the spiral lines which form the edges 
of the courses shall be parallel, and their distances shall be equal ; and 
the spiral lines which are the edges of the ends of the stones shall be 
developed in straight lines perpendicular to those lines which are the 
developments of the spirals of the edges of the courses. 

It is evident that each of these spiral lines will have a certain radius 
of curvature, and that this radius of curvature, at any point of the spiral 
line, will be equal to the radius of curvature at any other point in the 
same spiral; and that the radius of curvature at any two given points 
in two spiral lines which have parallel developments, are equal to one 
another. 
Therefore, if two points be taken in a spiral line, and if a straight 
line be drawn from one of them parallel to the axis, and if, through the 
other, the cylinder be cut by a plane perpendicular to the axis, and if 
_ the surface of the cylinder be developed; the development will be a 
right angled triangle, of which the quotient arising, by dividing the 
product of the square of the hypothenuse and the radius of. the cylin- 
_ der by the square of the development of the circular are intercepted 
_ between the spiral and the straight line, will be the radius of curvature 
of that spiral. 
__ By these principles the geometrical construction of an oblique arch 
may be easily made for the use of the workmen, or calculations of all the 
_ parts may be expeditiously and accurately performed by the engineer ; 
it is only necessary to have given the angle of obliquity of the acute- 
_ angled pier, the width of the arch within its abutments, the height of 
the intrados above the level of the springing, the perpendicular distance 
between the planes of the two faces, and the number of arch stones in 
each elevation, in order to construct the arch. 


On an Alteration in the Construction of Wollaston’s Goniometer, by 
which its Portability is increased. By W. H. Mivirr, M.A. 
F.R.S., Fellow and Tutor of St. John’s College, and Professor of 
Mineralogy in the University of Cambridge. 


In this instrument, which has a circle 4-4 inches in diameter, pro- 
_yided with two verniers reading to minutes, the branch which carries 
_ the crystal screws into the end of the inner axle, instead of being in one 
piece with it, as in the usual construction, and is taken out when the 
 Goniometer is put into its case. The distances of the milled heads, by 
which the circle and inner axle are turned, from the collar through 
_ which the axle of the circle passes, are considerably reduced. The 
foot of the instrument is a plate of brass 4°4 inches long, and 1°6 inch 
wide, capable of being fastened, by means of two screws, to one half of 
_ the case, which is provided with three adjustable foot-screws. A mirror 


154 EIGHTH REPORT—1838. 


of dark glass, making an angle of about 40° with the foot of the Go- 
niometer, an improvement which appears to have been invented inde- 
pendently by Mr. Sang and M. Degen, enables the observer to use an 
object seen by reflection for the lower signal. The whole packs into a 
case, the external dimensions of which are 5°5 inches long, 4°9 inches 
wide, and 1°7 inch thick. 


A short Account of a Method by which Engravings on Wood may be 
rendered more useful for the Illustration and Description of Ma- 
chinery. By C. Baspace, F.R.S. 


The principle of this method consists in making one woodcut, which 
represents a plan or projection of any piece of machinery. Several 
stereotype plates are then taken from this block, from each of which 
various parts of the mechanism are cut out, leaving only such parts as 
may be clearly understood together. 

The author illustrated this plan by impressions from several compli- 
cated woodcuts, intended for the description of his calculating engine. 
From one of these originals five stereotype plates had been taken and 
properly prepared. By removing certain parts from two of these 
plates, two different parts of the machine were shown; and by taking 
two other pairs of stereotype plates, each of these separate parts was 
again shown as dissected—one plate containing nothing but the fram- 
ing supporting that part, and the other nothing but its moving parts. — 
The author suggested the employment of this method for colouring 
geological maps. 


On the Odontograph. By Professor Wits, F.R.S. 


Professor Willis described his instrument called the Odontograph, — 
designed for enabling workmen to find at once the centres from which 
the two portions of the tooth are to be struck, so that the teeth may 
work truly together. The position of these centres is pointed out by 
theory, and this instrument may be considered as the practical means — 
of carrying out the theory*. He also described the construction and _ 
use of some scales of measurement invented by Mr. Holtzapfel. 


Description of an Improved Leveling Stave for Subterranean as well — 
as Surface Leveling. By Tuomas Sopwith, F.G.S. 


Of late years, the method of reading the figures of the stave itself, 
instead of using a sliding vane, has been adopted by the most expe- 
rienced engineers and surveyors. 

The staves now exhibited are of this construction. The figures are — 
engraved on copperplate on an enlarged scale, so as to contract in dry- — 
ing to the proper length, which is determined by a very accurate gauge. 


* Reports of British Association, vol. vi. p. 135. 


TRANSACTIONS OF THE SECTIONS. 155 


r. Sopwith described the improvements made by him in the con- 
struction of these staves, and also the use of a stave for subterranean 
leveling, the face of which is protected by a glass shield. It is hinged 
so as to admit of being used in any seam of coal from 8 to 5 feet in 
height; and the same principle may be applied to any greater or less 
extent. Mr. Sopwith stated, that from the experience of himself and 
_ assistants in conducting extensive leveling operations, fully one half 
time is gained, as well as great additional accuracy. 


Description of Instruments to facilitate the Drawing of Objects in Iso- 
: metrical Projection. By Tuomas Sopwitn, £.G.S. 


Mr. Sopwith exhibited several instruments, diagrams, &c., adapted 
to facilitate the process of isometrical projection. The first of these is 
a set of triangular rulers, the angles of which are coincident with the 
angles in the isometrical projection of a cube; and hence they can be 
applied with great ease and rapidity to the delineation of geometrical 
forms in isometrical drawings. 

Isometrical squares and circles engraved on drawing-paper are 
adapted to facilitate this mode of projection. The circles are gradu- 
ated; and hence any angles, whether on a horizontal or vertical plane, 
ean be correctly delineated and subsequently measured. Mr. Sopwith 
illustrated the advantages of this method of drawing by several exam- 
ples of its application to astronomy, to architecture, and to constructive 
designs generally. One remarkable property of isometrical drawings 
was pointed out, viz. that drawings made on a flat surface may have 
other flat surfaces pasted on by an edge, and which will appear in true 
‘projection when turned over upon the edge, and horizontal and vertical 
movements may be thus shown in one drawing ; thus forming what may 
be appropriately termed a picture model. 

_ The Isograph is an entirely new instrument, invented by Mr. Sop- 
with, for transferring plans from orthographical to isometrical projec- 
tion. This is effected by means of a simple mechanical movement. 
The isograph consists of a number of parallel rulers, made of brass or 
ivory, the fiducial edges of which are an inch distant. These rulers 
are fixed at each end by pivots to two brass bars, the centre of each 
Pivot exactly coinciding with the line of each fiducial edge. A brass 
gauge is used to fix this series of rulers so as to form a true geome- 
trical square; and when in this position, the principal lines or points 
are marked off upon the respective edges of the rulers. The instru- 
ment is then moved into a lozenge shape, and a gauge, equal in length 
to one side of the square, is fitted so as to form the shorter diagonal. 
‘Hence the opposite angles of the instrument are respectively 60° and 


_ The Isometrical Protractor, made of brass, is used for the delinea- 
tion of bearings in isometrical projection. A representation of a mi- 
ning district and a plan of Newcastle, drawn isometrically, were exhi- 
bited. : 


156 EIGHTH REPORT—1838. 


On an Improved Method of constructing large Tables or Writing-Ca- 
binets, adapted to save much time, and to secure a systematic arrange- 
ment of a great number and variety of Papers. By Tuomas Sopr- 
wir, £.G.S. 


In the arrangements of official business, in literary and professional 
pursuits, and in conducting «an extensive correspondence, great in- — 
convenience and loss of time result from the want of method conse- 
quent on papers being kept in various drawers, closets, boxes, &c., each 
requiring a separate key. The principle on which the improved wri- 
ting-tables are constructed is intended to obviate this inconvenience. 

Drawings were exhibited, showing various modes of constructing 
large writing-tables and cabinets in such a manner that, by means of a 
single key, the whole of the drawers, closets, &c., are at once opened, — 
and the whole of the partitions, drawers, &c., can be reached by any | 

| 


person writing at the table, without stirring from the seat in front. The 
whole, in like manner, is closed by a spring lock ; and the simplicity 
and strength of the arrangements are such, that the movements are not — 
liable to be deranged. One of the drawings represented a writing-ca- 
binet in Mr. Sopwith’s office, in the upper part of which there are one ~ 
hundred divisions for papers to be assorted, besides drawers for writing 
and drawing materials, and small shelves for colours and mathematical 
instruments. An upright door, hinged at the bottom, falls, when un- 
locked, upon a flat table, and forms a writing-desk; and any papers 
left upon it at the time of its being shut up, are of course ready to be re~ — 
sumed the moment it is opened again. This door is rebated on its three 
edges, so as to overlap the adjoining doors ; and the shutting of this 
door also forces in an iron bar, which fastens the drawers in the lower 
part of the table by a very strong and simple mechanical movement. 

There is also an apparatus for hanging keys upon, so that when any © 
key is removed, a slip of wood, with the name of the key upon it, falls — 
down so as to prevent the door from being closed; and the person 
using the desk is therefore reminded of having forgotten to replace the 4 
key. The facility of reference and arrangement admits of many short — 
periods of time being devoted to study or business which, but for such — 
an arrangement, would be totally lost. 


Suggestions on the practicability and importance of preserving National : 
Mining Records. By Tuomas Sorwirn, F.G.S. f 


The commercial prosperity of Great Britain mainly depends on its 
mineral productions. Whatever tends to promote economy in the | 
working of mines, and to afford increased facilities for the discovery of 
mineral treasures, eminently deserves the attention of every enlightened — 
statesman who regards the future as well as the present welfare of the — 
country. a 

The great value of, and increasing necessity which exists for, a re- _ 
gular system of preserving mining records, has been repeatedly urged — 


- 


- 


3 


TRANSACTIONS OF THE SECTIONS. 157 


by the most eminent and experienced geologists and miners. No such 
_ system has yet been pursued in this country ; and the importance of 
the subject renders it deserving of the attention of the British Associa- 
tion during its meeting in the midst of the mining districts of the north 
of England. 
Mr. Sopwith’s paper proceeds to point out the inconveniences and 
serious loss of capital, and even of human life, resulting from the pre- 
servation of mining records being neglected, and to explain several 
practical details connected with the subject. 


On Improvements in Ship Building. By Mr. Lane. 


Mr. Lang described and exhibited some models illustrative of the 
safety keel, which had been introduced with great success; and men- 
tioned instances in which vessels fitted with these keels had struck and 
come off without sustaining material injury. He then entered into 
some details respecting the proper construction of merchantmen, and 
exhibited some models of the bottoms of merchantmen*. He also ex- 
hibited a method of securing a round-headed rudder, and a model of a 
tube-scuttle to admit light between decks, and which had. been used 
with great success. 


On the Construction of a Railway with Cast-Iron Sleepers, as a Sub- 
stitute for Stone Blocks, and with continuous Timber Bearing. By 
T. Morrey. 


The cast-iron sleepers, which are wedge-shaped and hollow, having 
all their sides inclined inwards towards the under side, are to be laid 
transversely, and the timber is to pass longitudinally through the 
centre, and to be secured by wedges of iron and wood. The sleepers 
are to be six inches apart, and the timber of such a thickness as to 
prevent any perceptible deflexion betwixt the rails. The road is to be 
ballasted up to the top of the sleeper, and the timber to stand out suf- 
ficiently, and to have any approved rail laid upon it. 


_ On a Suspension Bridge over the Avon, Tiverton. By T. Motiry. 


The peculiar feature of this bridge is, that each chain is attached to 
the roadway, and the suspending bars are carried up through each 
chain above it. The length of the bridge is 230 feet, the breadth 14 feet, 

and the cost, including the towers and land abutments, under 24002. 
_ This bridge is superior to the common suspension bridge, in that it is 
more firm, and experiences much less friction, owing to the absence of 
vibration. 


* See Reports of the British Association, vol. vi. p. 135. 


158 EIGHTH REPORT—1838. 


On an Improved Method of constructing Railways. By J. PrRIcE. 


This method consists in fixing rails on a continuous stone base, a. 


groove having been made in the stone to receive a flange or projection 
of the lower side of the rail. The stones and rails are to break joint 
with each other, and the chair by which the rails are to be secured is 
to be made fast to the rail by a bolt, not riveted, but slipped in. The 
chair is to be sunk until the top is level with the top of the stone, and 
fastened to it by two small wooden pins. Any sinking of the road is 
to be obviated by driving wedges of wood underneath the stone until 
it is raised to the required height. The chairs are to be fixed at about 
four feet apart, and to weigh, if of malleable iron, 14 pounds; but if 
of cast iron, 20 pounds: the rail to weigh 50 pounds per yard. 


Machine for raising Water by an Hydraulic Belt. By Mr. HALt. 


In this machine, an endless double woollen band, passing over a roller 
at the surface of the earth, or at the level to which the water is to be 
raised, and under a roller at the lower level, or in the water, is driven 
with a velocity of not less than 1000 feet per minute. The water con- 
tained betwixt the two surfaces of the band is carried up on one side 
and discharged at the top roller by the pressure of the band cn the 
roller, and by centrifugal force. This method has been in practice for 


some time in raising water from a well 140 feet deep in Portman Mar- 


ket, and produces an effect equal to 75 per cent. of the power expend- 
ed, which is 15 per cent. above that of ordinary pumps. This method 
would be exceedingly convenient in deep shafts, as the only limit is the 
length of the band, and many different lifts may be provided. 


On Cliff's Dry Gas Meter. By Mr. Samupa. 


This instrument consists of a pulse glass, that is, two thin glass globes 
united by a tube. These globes are partially filled with alcohol, and 
hermetically sealed when all the air is expelled from their interiot. In 
this state, the application of a very slight degree of heat to one of the — 
globes will cause the alcohol to rise into the other. The pulse glass is 
fixed on an axis, having a balance-weight projected from it, and the 
axis works in bearings on the sides of a chamber through which the 
gas to be measured is made to pass the gasometer in two currents, one 
of which is heated and the other cold. The hot gas is made to enter 
opposite to, and to blow upon the top globe of, the pulse-glass, while — 
the cold gas blows upon the other. The difference of temperature thus 
established between the globes causes the alcohol to rise into the upper — 
one, and the glass turns over on its axis, thus varying its position, and — 
bringing the full globe opposite to the hot stream of gas. This stream, 3 
with the assistance of the cold gas, which condenses the vapour in the 


TRANSACTIONS OF THE SECTIONS. 159 


op globe, repeats the operation, and the speed at which the globes 
oscillate will be precisely in proportion to the quantity of gas which 
has been blown upon them, provided a uniform difference of tempera- 
ture is always maintained between the two streams of gas. The dif- 
_ ference of temperature is established and rendered uniform by a small 

flame of gas, which heats a chamber through which the lower current 
_ of gas has to pass, and the arrangements for securing an equality in 
_ the difference of temperature are very ingenious. The instrument is 
first tested by making a given quantity of gas pass through it, and ob- 
serving the number of oscillations of the pulse-glass. This once esta- 
blished, the instrament registers the quantity passed with extreme 
accuracy. 


Sir John Robison mentioned a circumstance which he considered of 
peculiar importance to the lower orders. Mr. Strutt, of Derby, to 
whom the country owed so much, had some years ago expressed to him 
an opinion, that coal-gas would be found by the lower orders the 
cheapest fuel for cooking. This he had applied; and the whole appa~- 
ratus, which might be considered as the converse of the Davy safety- 
lamp, consisted in fixing a piece of wire-gauze at the extremity of a 
gas-pipe of about six inches in diameter. He referred to the account 
in Loudon’s ‘ Encyclopedia of Cottage Architecture,’ for some valuable 
-remarks and directions on this subject. The wire-gauze was liable to 
_ be destroyed under a long-continued intense heat: this, however, was 
obviated by sprinkling a small quantity of sand upon it. Bulk for 

bulk, gas was more expensive than coal, but the former was more eco- 
tomical and convenient for occasional use and the smaller operations 
in cooking. 


Sir John Robison explained a model of the bucket of a pump in use 
in Sweden, the peculiar feature of which was, that the pressure of the 
sides of the bucket outwards against the pipe is exactly proportional 
_to the load to be raised. This bucket is peculiarly applicable for rai- 
sing foul water. 


On a New Day and Night Telegraph. By JosrpH GARNETT. 


The paper on this subject was accompanied by a model, to exhibit 
the construction and method of working of the telegraph, which it is 
‘proposed should consist of two ladders, about 41 feet long, framed 
together at about 24 inches asunder at the bottom, and 20 at the 
top, so as to constitute the frame for the machinery. There are two 
arms, one at the top, the other about midway up the frame-work, coun- 
_terpoised by weights, and worked by machinery, consisting of 8 bevel 
mitre wheels. At the bottom of the frame-work is a dial plate, with a 
_ pointer, and the workman, in setting the pointer, brings the arm of the 
telegraph into the required corresponding position. 


160 EIGHTH REPORT—1838. 


On an Improved Method of working the Valves of a Locomotive En- 
gine. By Mr. Hawtuorn. 


Professor Willis described the method recently introduced by Mr. — 
Hawthorn, for working the valves of a locomotive without the usual 
eccentrics. The motion is derived at once from the connecting rod, 
by means of a pin placed at the centre of the connecting rod, and giv- — 
ing to a frame a reciprocating motion in a vertical direction at every — 
revolution of the crank. To this frame are attached arms, by which 
motion is communicated to the slides. It is necessary that the slide 
should be open for the admission of the steam into the cylinder, a — 
little before the piston has completed the stroke; this, which is techni- 
cally termed the /ead of the slide, must be provided for with great care, 
so as to correspond with the various speeds of the piston ; this arrange- 
ment cannot be made where eccentrics are used without considerable 
difficulty ; but this is provided for in Mr. Hawthorn’s method by sim- 
ply changing the angle at which the frame is set, an operation which 
can be performed by adjusting a screw. 


On the Application of Machinery to the Manufacture of Steam-Engine 
Boilers, and other Vessels of Wrought Iron or Copper, subject to 
Pressure. By Wm. FairBalrn. 


bat gates came errno nt 


Having described the usual process of hand-riveting, and the im- — 
perfections to which it is subject, the author adverts to the riveting — 
machine, which obviates these defects, and produces sound and perfect 
work. As the time occupied in the process of hand-riveting, allowing 
the rivet to cool, and thus destroying its ductility, is the chief cause of 
all the defects, it is evident that an instrument having a force to com- 
press the rivet within an indefinitely short period must obviate or en- 
tirely remedy these evils. ‘The commencement of the process is the 
same in both methods. Ina circular boiler, such as is represented at 
A, in the annexed figure, the plates having been first bent to the circular 
form, with all the requisite holes punched in them, two rings of plates 
are put together by temporary bolts, and suspended over the machine, 
by three chains, from blocks over the centre of the boiler. These blocks 
are arranged to move backwards and forwards for circular boilers, to 
suit any diameter, and are also made to move crossways for plain flat 
work. Having now placed the boiler so as to inclose the circular por- 
tion of the machine marked 1, (which performs the part of the “ holder- 
on,”) and having brought the rivet-holes in a line with the dies marked 
1 and K, a rivet being previously inserted, and the bent lever c, turnin 
on the centre rR, being lifted up by the power used to work the machine, _ 
—the die 1 is advanced through the fixed head Pp, and the rivet is now — 
compressed with great force against the die k. The faces of the dies — 
have each a circular cavity, when employed in the performance of the — 
usual work, but may be formed so as to give any required shape to the — 
head and point of the rivets. . 


Aa. 
"ty 
- 
5. 


md 


TRANSACTIONS OF THE SECTIONS. 161 


_ From this description it will appear evident that no time is lost ; that 
ho hammering of the rivet takes place after it is cooled, to render it 
brittle: but the action is completed so rapidly, as to leave it in a per- 
_ fectly sound and ductile state. This is a point of the utmost import- 
_ ance, as the joint is so firmly united by the subsequent cooling and 
_ contraction of the rivets as to render the usual precaution of “ caulk- 


xSO9D90C A000 


Wpsent2 0005009000 


almost unnecessary. Caulking is an operation universally adopted 
to prevent leakage, by setting up the edge of the plates upon the seam 
or joint with a hammer and a square-ended tool of cast stecl. 

_ By the use of the machine much time and labour is saved, by the 
itution of instantaneous compression instead of a long series of 
acts. It is applicable to all kinds of circular tubes and boilers, and 
uso to every description of flat and square work. It fixes and com- 
VOL. vil, 1838, M 


162 EIGHTH REPORT—1838. j 


pletes eight rivets of three-fourths of an inch in diameter in a minute, 
with the attendance of two men and two boys to the plates and rivets; _ 
whereas the average work that can be done by two riveters and one 
holder-on and a boy, is 40 three-quarter rivets per hour; the quantity _ 
done in the two cases being 40 to 480, or in the proportion of 1 to 12. 


On a Steam-engine Boiler. By J. Price. 


The author exhibited a model of a steam-engine boiler of 18 horse 
power which is at work daily at the Durham Glass-works, Gateshead, 
and described its peculiar construction and advantages in regard to- 
safety and cheapness. 

He states, that by the construction of the flues the whole of the 
heat is rendered available. Owing to the draught, the dust that accu- 
mulates in the flues is only ten pounds per week. 

There are two cocks in the laggings of the furnace, and three along ~ 
the bottom of the boiler to let off water and sediment when required; _ 
in consequence of which there have only accumulated 294lbs. of thin — 
mud in six weeks, which contains 2 oz. 6} drachms of fine powder. — 
He mentions, as one principal advantage of this boiler, the impossi- _ 
bility that either flues or boiler can collapse. 

A steam safety-valve is applied in the form of a ball in a cup which 
rises from its seat and allows the steam to escape so soon as it comes to 
within one pound of the safety pressure ; it is covered with a cap, which — 
is secured by nuts within the boiler, and cannot be removed or — 
weighted without cooling the boiler: consequently it is beyond the 
reach of the working engineer, who has his own valve to regulate as he 
likes. : 


A New Rotatory Steam-Engine. By 8. Row ey. 


It was stated by Mr. Evans, that the novelty in this construction — 
consisted in the excentric being on the inside. 


4 

Remarks on the Construction of Steam-Boilers. By W. GREENER. : 
Mr. Greener stated his opinion, that the accidents which happen to — 
“steam-boilers are principally due to defect in the material of which — 
they are constructed. He detailed several experiments made on slips 
of iron cut from plates of different quality. He found that slips cut — 
latitudinally from a plate sustained less pressure by 30 per cent. than — 
slips of the same dimensions cut longitudinally ; in some cases the dif, 
ference was much greater. He also had immersed plates in a mixture” 
of sulphuric acid and water, and found that the injury done in twenty- 
four hours varied from 61 to 15 per cent. of the original strength. 
Many boilers will stand so long as the form remains perfect ; but should 


4 


TRANSACTIONS OF THE SECTIONS. 163 


any part, as the crown of the arch, in cylindrical boilers, collapse, an 
accident becomes probable. 


On a Substitute for the Forcing-Pump in supplying Steam-Boilers, 
$e. By Mr. Mavte. 


This was a hollow cock having an orifice, which being uppermost, 
_ the plug became filled with the liquid, and then, being turned half 
_ round by the motion of the piston, the liquid could run into the vessel 
below. 


Notices on the Resistance of Water. By Joun Scott Russe Lt, 
F.RS.E. 


The author, in conjunction with Sir John Robison, being still en- 
_ gaged in researches bearing on this subject, it is deemed unnecessary 
_ to anticipate by partial notices the full Report which is expected from 
_ these gentlemen. 


On Methods of Filtering Water. By J.T. Hawkins. 


In this paper the author detailed the various essentials for a durable 
and simple filter for obtaining pure water. The charcoal must be per- 
fectly well burnt, and kept from exposure to the atmosphere. A test of 
good charcoal is, that when pulverized, it sinks rapidly in water. The 
_ charcoal must be supported on an indestructible material, as a plate of 
burnt clay perforated with holes. The filter may consist of a common 
_ garden-pot, or similar vessel, with holes at the bottom: the lower part 
may be filled with round pebbles, then some smaller pebbles, then some 
coarse sand, and finally a stratum of pounded charcoal, of about three 
_ or four inches in thickness. It is a great mistake to put any material, 
as sand, above the charcoal, with the view of arresting the grosser par- 
_ ticles of impurity, as the sand will quickly stop up, and be impervious 
to water. A filter thus prepared will render water perfectly clear and 
sweet for many years. 


On a Method of making Bricks of any required Colour. 
By Mr. Dosson. 


On Coal-Mine Ventilation. By Mr. Fourness. 


___Models were exhibited and partially explained of a suspension bridge 

of wire, erected over the river Avon, near Bath, by Mr. Dredge. 

A method of Pumping Water from Leaky Vessels at Sea, by Mr. Dal- 

wziell. The machine is worked with a piston, the motion of the vessel 
M 2 


164 EIGHTH REPORT—1838. 


being given by the steam when the vessel is sailing, to paddle-wheels 
on the sides. An instrument for measuring Timber, by J.Smith. 
A peculiar Combination for the Wheel-Work of a Crane, by W. Horner. 


On the Water-works of Newcastle-on-Tyne. By Josrru GLyxy, 
F.RS., M. Inst. C.E., §e. &e. 


In the month of April 1833, Mr. Glynn was requested, by a body of 
gentlemen in Newcastle, to report to them the best means of supplying 
the dense and increasing population of the town with water, the want 
of which was daily becoming more urgent. 

A water company already in existence, incorporated by an act or 
charter of ancient date, claimed a right to all the springs which had 
been or might be discovered for the supply of the town. But as all the 
higher portions of land have been perforated by coal works and quar- 
ries, and the town stands on a hill sloping rapidly to the Tyne, it was 
obvious that from natural springs or from wells an adequate supply 
could not be obtained. In a long course of years the shares of the 
ancient company had fallen into the hands of a few persons not dis- 
posed to invest their money in new and extensive works; their pipes 
were chiefly of wood, with a small portion of leaden pipes, none exceed- 
ing six inches in diameter, and all incapable of bearing much pressure. 
It was therefore necessary to have recourse at once to the river Tyne. 
Recent experiments on the largest scale had shown that the water of 
rivers flowing past populous towns might be applied with advantage to 
the purposes of domestic uses, after being rendered free from impurity 
by artificial filtration. For the lower or filtering station Mr. Glynn 


fixed on a field at the river-side, near Elswick, 514 feet above low- — 


water mark, this elevation lessening the great height to which it was 


requisite to force the filtered water. The upper reservoir, near the — 


Quarry House on the west turnpike road, being at its lowest part 237 


feet above low-water mark, or about 186 feet above the level of the 


works at Elswick. The bottom of this reservoir is level with the arches 


of the crown on the tower of St. Nicholas church above the statues on — 


the corner pinnacles. 

As the town then contained a population, by the latest estimate, 
amounting to 54,000, and about 3500 houses of 10/. and upwards of 
annual value, the number of which was fast. increasing, it was recom- 
mended that the new works should be capable of supplying at least 


400,000 gallons per day of filtered water, and that the upper reservoir 


should contain not less than four days’ water at that rate of consump- 


tion. As the flood-tide brings up a portion of salt water, it is neces-— 
sary that the supply should be raised when the tide is down, and to 4 


pump it in a short time. A steam-engine, having a cylinder 54 inches — 
in diameter, with a stroke of 8 feet, was therefore erected at the works 
at Elswick, with three boilers, any two of which are capable of working — 
the engine, 


i 


TRANSACTIONS OF THE SECTIONS. 165 


The engine works two pumps of different sizes; one of them raises 
the daily supply from the river in three hours, and the other forces it 
in eight hours to the upper reservoir, through a main pipe of 14 inches 
diameter and 1700 yards in length. 

The water when raised from the river is received into “subsidiary 
tanks” of brickwork set in Roman cement, of which there are two, each 
of them containing a day’s supply; by this means it will take 24 hours 
to settle and deposit the earthly particles suspended in it before it be 
suffered to run upon the filtering apparatus, which is a large brick tank, 
containing a series of beds or strata of sand and gravel, resting upon 
brick tunnels set in Roman cement, the uppermost bed being of fine 
sand, the lowest of pebbles. The area of the filter bed is 10,000 square 
feet; the water filters by descent, and is received into the tunnels, 
whence it is forced by the steam-engine through the main pipes a di- 
stance of 1700 yards, to a height of 200 feet to the high reservoir, and 
is thence distributed in cast-iron pipes of various diameter over the 
whole of the town. These works have been completely successful. 
The ancient company have disposed of their charter and their wooden 
pipes to the directors of the Subscription Water Company, who, during 
the meeting at Newcastle, opened their works for the inspection of the 
members of the British Association. 


STATISTICS. 


On Educational Statistics of Newcastle. By Mr. Carctuu. 


From this paper it appears, that of a population of 64,000, and of 
16,000 children between the ages of 5 and 15, there are 7761 or 484 
per cent. of the whole, apparently receiving no education, either real or 
nominal, in schools. In a district of the town, every place of abode 
in which was visited, and the number of children from 3 to 15 years of 
age found to be contained 4352, it appears 444 per cent. were found 
able to read and write: of 736 persons who registered births and 
deaths in all the parishes, 513 could not write, or 41 per cent: of 1264 
persons committed to prison, chiefly for grave offences, during 18 months, 
only 30 could read and write well. A large proportion of the schools 
for the poor were found totally inadequate for the purposes of real edu- 
cation, and the teachers often as ignorant as the scholars. That the inhabi- 
tants of alarge district (26,000), were in general living in astate of misery 
and apparent destitution, though the wages earned by a great part were 
as high as 18s., 21s., 25s., 30s., and even as high as 40s. per week,— 
_ showing the inadequacy of high wages alone to produce the happiness 
arising from order, cleanliness, and mental culture, when improvidence, 
_ drunkenness, &c. &c. retain a hold of the working classes. 


166 


On the Church- and Chapel-room in All Saints’ Parish, Newcastle. By 
D. H. Wixson, in a Letter to A. Nicuor, Esq. 


EIGHTH REPORT—1838. 


NAME. DENOMINATION. /|SEATS. ~. AUTHORITY. 
Church of England Circu- 
All Saints’ .....e.s0+0 Established Church ...| 1400 lar in behalf of Byker 
Chapel of Ease. 
St. Afin’s '......00.. .| Ditto ......+6 a 500 | Ditto. ‘ 
“ Biviass .. Private information, under 
Silver Street ......... Primitive Methodist ...| 900 rather than siuaetheatenib, i 
: - 7 Richardson’s Companion 
Friends’ Meeting ...| QuakerS......sseseeeerees 500 through Newcastle. 
Roman Catholic ...! Roman Catholic ...... 1500 | Ditto. 
Carlisle Street ...... Presbyterian Ditto, 
Bethel — ...ss+ sities Ditto Ditto. 
Walknoll ........+. +..| Ditto Ditto. 
Forster Street «...... Glassites Private information. 
é Richardson’s Companion 
New Road.........+6 Wesleyan Methodist. through Newcastle. 
4 Ditto, but reduced in size 
Ebenezer .......s0000. New Connexion ...... 150 nnn bia report, 
Gibson Street ...... Wesleyan Association -| 1200 | Ditto. 
Stepney Bank ...... Wesleyan Methodist...| 200 | Private information. 
Ballast Hill ......... Primitive Methodist... 150 | Ditto. 
St. Peter’s Quay ... eas a } ...| 500 | Richardson’s Companion. 
St. Lawrence......+.. Wesleyan Methodist...) 150 | Private information. 
Sandgate .......ss.++ Independent ............ 200 | Ditto. 
Sailor’s Bethel, Quay} Various Dissenters ...} 130 | Ditto. 
Trinity Chapel ...... Church of England...) 60 | Ditto. 
10,560 


A Return of Prisoners coming under the cognizance of the Police in 
Newcastle, from the 2nd of October, 1837, to the 2nd of August, 1838. 
By Joun STEPHENS. 


The total number was 2169; of whom 1274 were convicted, 20 ac- 
quitted, and 875 discharged ; but of the number of offenders 267 were 
strangers in the town. There were only 17 cases of manslaughter, 
highway-robbery with violence, burglary, and shop-burglary, and 12 
of these offences were by strangers. Of the rest of the offences, 325 
were for assault, and 617 being drunk and disturbing the public peace, 
and 283 lying insensibly drunk in the streets: so that nearly one-half 
of the offences were for drunkenness. The committals, to the popula- 
tion, were 1 in 275 inhabitants, or 3°4 per cent. Seventy-eight of the 
offenders returned to an honest means of livelihood. 

The offences under the Bye-Laws, Town Improvement Act, Beer 
Acts, &c., independently of the above, were 382 ; of which number 98 
were discharged. In this return the disorderly beer-houses appeared 
to be 30. The total offences therefore are 2551, or 1 in 25:1 inha- 


TRANSACTIONS OF THE SECTIONS. 167 


 bitants, or 4 per cent; but this apparently large proportion of commit- 
tals is equalled in London, where in 1836 every 1 in 24 of the inha- 
bitants, or 4°09 per cent were committed. 


Statistical Notices of the Asylum for the Blind lately established at 
Newcastle-upon-Tyne. By Rev. J. M‘AvisTER. 


Some tables were presented to the meeting, showing the relative 
proportion of the blind and seeing in a particular district of the town, 
from which it appeared that the proportion of blind was greater than in 
any of the late continental returns. 

The author of the paper stated, that the great number of wandering 
blind which frequented some parts of the suburbs, had induced a few 
benevolent individuals, during the last year, to direct their attention to 
some means for improving the condition of this neglected portion of 
the population. An asylum had been opened for a small number of 
blind at first, to test the various modes of instruction. A. competent 
master and matron having been appointed, the inmates were soon en- 
gaged in learning various branches of manufacture suitable to their 
capacities. After the trial of different alphabets, they were now taught 
to read in books from the press of Mr. Alston of Glasgow, the alphabet 
employed being the raised Roman character. This system was on 
many accounts considered preferable to an arbitrary system of typo- 
graphy. 

In the course of his attention to the internal economy of institutions, 
the author has found, that although it is very practicable-to teach those 
born blind to read, yet it is a truly difficult task to teach them to think 
_ accurately. In every passage where a visible image is introduced to 
_ them, the meaning is more or less vitiated; and the integrity of the 
intellect, by indulging a habit of receiving what it cannot understand, 
is sadly endangered, unless a careful and peculiar mental culture ac- 
company all literary instruction. 


On the State of Agriculture and the Condition of the Aricultural La- 
bourers of the Northern Division of Northumberland. By Mr. Hixp- 
MARSH. 


In this paper the author gave an interesting account of the mode of 
_ employing labourers, in the north of Northumberland, by the system 
of bondagers, who are employed by the hinds, and the hinds are them- 
selves in the employment of the farmers. 

(See Statistical Journal, Nov. 1838.) 


_ Dr. Taylor read a paper, communicated by Saxe Bannester, Esq., 
_ on the population of New Zealand. It described the state and condition 
- of the natives, the white residents, the white visitors, and the mixed 


168 EIGHTH REPORT—1838. 


race. This paper also related the laws of New Zealand relating to land, 
and yery minutely detailed the moral, social, and political condition of — 
the white settlers, the progress of commerce, and more especially, the 
exports and imports of the Bay of Islands. 


- 


Statistical Report of the Parish of Bellingham in Northumberland. 
By W. H. Cuaryton. 


This report comprised a detailed reply to the statistical queries put. 
forth by the Society in London. 


(See Statistical Journal for November 1838.) 
The following are extracts :— 


The Population in 1811 was 1232 Increase per cent, 
jade oma 1821 .. 1396 133 
Tbe. ESO]. 1460 4d 


State of Education—Parish of Bellingham. 


Number who could read, 1319. Number who could write, 551, 
Families. Members. ey, / Families. Members. Writers. 
77 461 All. 2 14 All. 
26 99 86 505 1 
54 288 2 62 390 2 
32 201 3 29 196 3 
35 238 4 23 203 4 
25 184 5 6 40 5 
17 152 6 4 41 6 
14 126 a 3 28 7 
7 63 8 I 9 8 
4 45 9 1 14 9 
6 72 10 2 35 10 
1 21 ll 86 528 None. 
11 50 None 
309 2000 309 2000 


On the Statistics of Ramsbottom. By P. M‘Dowatt. 


The following are extracts:—Houses: No. of cottages, 309; with 
good furniture, 294; with bad, 15; with one bedroom, 137 ; with two, 
172. Several of these families numbered from 2 to 13 persons. Fa- 
milies: males, 968; females, 1032;—total 20C0: married, 285; and — 
having no children, 5. No. of widows, 24. Lodgers: males, 50; fe- 
males, 33;—total 83. Ages: above 50, 81; 60, 28; 70, 11; 80, 3. 
Total number who receive wages, 1134. Total number who could 
read, 1319. Total number who could write, 531, 


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170 EIGHTH REPORT—1838. 


A Series of Statistical Illustrations of the principal Universities of Great 


Britain and Ireland. By the Rev. H. L. Jones, M.A. 


These illustrations consisted principally of tables, in which Mr. Jones 
calculated the amount of income derived from the ancient endow- 
ments of the colleges, and from various other sources of revenue, 
the degrees conferred in the Universities, and the number of members 
qualified by their degrees to take a part in the government of the 
Universities. 

At the present time, it appears that the total number of members in 
each of the two great English Universities, of Oxford and Cambridge, 
exceeds 5000, and that the number of resident members in each of these 
Universities is about 1600. 

Mr. Jones states that the total annual expenditure of 1600 members 
amounts to about 480,000/. per annum in Oxford, and about 400,000/. 
per annum in Cambridge. 


A Description of the “ London Fire Engine Establishment,” and of the 
Number, Extent, and Causes of the Fires in the Metropolis and its 
Vicinity, during the Five Years from 1833 to 1837. ByW.R. Rawson. 


It appears that the average annual number of fires during this period 
was 495, the number of alarms from chimneys on fire 108, and the 
number of false alarms 68. 

Of the total number of fires, nearly one third occasion serious damages, 
and in 6 out of 100 instances the buildings were wholly consumed. In 
13 instances, 2 buildings were destroyed by a single fire ; in 4 instances, 
3 buildings ; in 6 instances, 4; in 2 instances, 5; and in 1] instance, 8. 

The number of fires is on the increase, but probably not out of pro- 
portion to the great increase of buildings. 


The number of fires accompanied by loss of human life was 41; the — 


number of lives lost was 57. 

It appears that although the greatest number of fires have occurred in 
December, yet the number from May to October slightly exceeds that 
from October to May. 


Private houses and the dwelling parts of other houses furnished — 


nearly one half of the whole number of fires. Next in frequency were 
sale-shops or offices, victuallers, carpenters, bakers, oil- and colour- 


men, stables, cabinet-makers, tinmen, booksellers, warehouses, hat- — 


makers, &c. The number of fires in the houses of lucifer match-makers 
was considerable. 

The causes of fires have been discovered in four-fifths of the cases. 
Of these causes accidents from candles form by far the largest class, or 
3 in 10 cases; and of these 43 per cent. arose from the setting on fire of 
bed-curtains ; 22 per cent. from the setting on fire of window-curtains, 
and 35 per cent. from other accidents. The next most frequent cause is 
the defective construction or imperfect cleansing of flues, chimneys, and 
stoves, amounting to 22 per cent. of the whole number. The number 
of accidents from gas was 74 per cent., from fire-heat applied to various 


- 
* 
a 
Si 


gr oT 


TRANSACTIONS OF THE SECTIONS. 171 


_ processes 7 per cent., and from linen hung before the fire 8 per cent. 
These are the principal causes. The number of wilful fires was small, 
only | in 64 fires. 

As regards insurance, two-fifths of the houses were wholly uninsured; 
one-third were insured for both building and contents; 11 per cent. 
_ were insured for the building only, and 17 per cent. for the contents 
only. 

During the five years under review only 5 large fires have occurred 
_at which property to the extent of more than 20,000/. has been de- 
stroyed. These were the Houses of Parliament, in October, 1834; a 
fire in Silver-street, Golden-square, in March 1835; that at the Western 
Exchange, in March 1836; that at Fenning’s Wharf, in August of the 
same year; the fire at Davies’ Wharf, in December 1837. The only 
_ large fire this year was at the Royal Exchange, on the 10th of January. 


Abstract of the Report of the Railway Commissioners in Ireland. 
By W. R. Rawson. 


The Commissioners of Railways for Ireland have founded their re- 
- commendations upon the distribution and employment of the population, 
the commerce, traffic, and number of passengers in the various districts, 
_ the facilities which the geological features of the country present, and 
_ the comparative power of the several districts to avail themselves of 
railway communication. 
It appears that the population is most dense in the northern counties; 
‘next in order are the midland counties, east of the Shannon; and then 
the southern counties of Tipperary, Limerick, and parts of Cork and 
Waterford. The population in the north is in the best condition, then 
that in the south; the midland districts nearly resemble the southern, 
but the western is far inferior to either. 
_ The order of the principal towns as regards the amount of their 
traffic, is as follows: Dublin, Cork, Belfast, Limerick, Waterford, 
Galway, &c. Their order as regards the value of imports and exports 
is the following: Belfast, Dublin, Cork, Waterford, Londonderry, 
Newry, Limerick, &c. The returns of the amount of passengers, 
traffic, of postage collected, and of banks, confirm the preponderance 
of Dublin, Cork, Belfast, Limerick, and Waterford. The efforts there- 
fore of the commissioners have been directed to lay down lines of rail- 
way between these towns. The geological features of the country offer 
peculiar facilities for effecting this object, the principal part of the pro- 
_ posed lines being carried through a country of carboniferous limestone, 
the most level and easy formation for such works. 
'__ The commissioners propose two main lines, one to the south from 
Dublin to Cork, throwing off branches to Kilkenny and Limerick, the 
expense of which they estimate at 2,329,000/,, and the annual profit 
at 34 per cent. upon that sum. Connected with this line is a branch 
from Limerick to Waterford, the cost of which is estimated at 400,000/., 
and the annual dividend at 32 per cent. 


72 EIGHTH REPORT—1838. 


The proposed lines in the north are, from Dublin to Cavan, and — 
thence two branches, one to Armagh, to join the line already com- — 
menced to Belfast, and the other in a north westerly direction to Ennis- — 
killen. The cost of these two lines is estimated at 2,015,000/. If this 
line, which will be more expensine than the south, cost 11,000/. a mile, 
the annual return will be 42 per cent. 

It is impossible upon the. present occasion to enter more fully into 
the extensive and important subjects embraced in this report. 1 


Abstract of Statistics respecting the Working Classes in Hyde, Cheshire. 
By W. FELKIN. : 


The township of Hyde contained 830 inhabitants in 1800—upwards ~ 
of 11,000 in 1837. The overseers’ report of expenditure for the — 
latter year was, to 9 resident paupers, 56/. 4s. 10d.; 3 deceased 
paupers, 15/. 2s. 6d.; 3 insane, 20/. 6s. 8d.; 18 paupers ‘living out of — 
the township, 115/. 9s. 10d.; being 207. 3s. 10d. to 18 men and 15 _ 
women (of the latter, 4 widows) ; total, 33 paupers ; added to which, 
expenses for law, and removals, and medicine, 17/7. 16s. 5d.; workhouse, — 
61. 13s. 6d. ; overseer and sundries, 847. 19s. Od.:—making 3167. 12s. 9d. 
total expenses for paupers. 

Population engaged entirely in factory and retail trade, and getting 
the coals they consume; highway rate 750/. for same year. In 1800, © 
the poor rate was 19s., in 1837, 6d. per head, perannum. On examining 
one of the factories (employing 1600 hands), and the dwellings of many — 
of the hands, there was found one public house, and no spirit, beer, or — 
pawn shop; well furnished cottages generally ; a good rate of wages, — 
25s. men, 12s. women, 4s. children; average 12s. 6d. of the whole. 
73 men’s earnings were 78/. 15s. Od. a year. The earnings of 120 fa- 
milies averaged 6s. 103d. including every individual composing them. ; 
Their income was about 1201. a year; 3 felonies had been committed 
in 35 years by those employed in this factory. None had ever been i 
pauperised, nor had pauper relatives living in the town, when the census _ 
took place a few weeks ago. Ten of the workmen possess 46 cottages, — 
rated at 7/. or 8/. each, bought by their savings; and about 300 more 
belong to probably 40 others. ‘These houses are good and substantial 
dwellings. They are fond of music, and cultivate it; no dwelling was 
without a Bible or New Testament, and generally other books and pic=- 
tures. Children well taught and in good schools ; many were seated at_ 
meals both substantial and good. But few gardens or flowers. Intema ; 
perance gradually decreasing ; and though many well-paid families live 
always upon credit, yet prudence, benevolence, and good morals gene- 
rally prevail, not only in these but amongst 4 or 5000 of the surround- 
ing workpeople. 

Other large manufacturing establishments which have been visited, a 
show the excellent influence and effects of wise and economic principles — 
and management upon the happiness of the workpeople and the com~_ 
munity. 


sz 


TRANSACTIONS OF THE SECTIONS. 173 


"i 
_ A Short Account of the Darton Colleries' Club. By T. Witson, FSS. 


The Society thus designated must be considered purely as an expe- 
-riment—as an attempt to ascertain, in certain circumstances, on what 
terms a miner might insure fo himself and his family a certain “ relief 
during any illness that might arise from any accident happening to 
them while at work.” 
The Club was established in February 1833 at Silkstone Colliery, 
near Barnsley, and has since been adopted at the Darton Colleries. The 
subscriptions are deducted from the wages of the men, the allowances 
_have been paid and the accounts kept by the owner of the mine, and 
the meetings have been held at the Colliery ; so that all expenses have 
been avoided, and the funds may be considered as wholly applicable to 
the purposes of relief. 

A member whose wages are less than 7s. a week, pays 6d. on entrance, 
and one halfpenny per week, and receives when ill 3s. 6d. a week so 
long as the illness continues ; all whose wages exceed 7s., pay 1s. on 
entrance, and one penny per week, and receive when ill 7s. a week. 


No. OF SUBSCRIBERS. 
YEARS, |—____________________| Accidents| RECEIPTS, PAYMENTS. 
Minimum, |Maximum.| Average. |Chargeable. 

& PANG ae sal als 

1833 93 125 107 5 24 7 {11 7 | 14 0 

1834 115 232 158 33 41 9 21 24 | 14 0 

1835 197 228 212 52 47 | 3 3 | 40 7 4 

1836 200 243 224 45 52 8 1 | 51 9 6 

1837 217 272 245 53 56 | 12 8 | 72 | 16 0 

1838 262 289 277 22 36 | 12 7 | 11 2 0 
August, ee SE) CS | 

258 | 13 83/208 10 


The surplus fund is now £50 10s. 103d. 

No account of the cause and nature of the accidents was kept previous 
to July 1836, since which time 96 accidents have occurred which have 
_ been chargeable to the Club. Of these, 90 have been reported with 
_ their causes, of which the following is a summary :— 


25 from the roof falling, 
20 from the coal falling, 
19 from corves hurting them, 
6 from falls, 
” from wounds from tools, 
8 from various things falling on them, 
5 from fire damp. 


90 


_ A Letter was read to the Statistical Section, from the Rev. Dr. 
Porter, accompanying a donation of the last Annual Reports of the 
_ Regents of the University of the State of New York. 


174 EIGHTH REPORT—1838. 


A Statistical View of the recent Progress and present Amount of Mining — 
Industry in France, drawn from the Official Reports of the “ Direc- — 
tion Générale des Ponts et Chaussées et des Mines.” By G. R. 
PoRTER. ae ee 
The data from which the reports of the French Mining Engineers 

are drawn are collected under the authority of a law passed by the Le- 

gislative Chambers in 1833; and Mr. Porter draws attention to the 
fact, that the productiveness of mining industry in France has increased 
in a greatly accelerated ratio since that time as compared with previous 
periods, which circumstance he considers is, in part at least, attribu- 
table to the suggestions made to proprietors of mines and works by the 
engineers, a highly educated and intelligent body of men, to whom 
the task of inspection is confided ; and occasion is thence taken to point 
out the desirableness of adopting some system for the collection of 
similar data in this country. The value of the coal, iron, lead, anti- 
mony, copper, manganese, alum, and sulphate of iron produced in 

France, has been increased from 4,230,000/. in 1832 to 6,170,000/. in 

1836, or 45 per cent, while the increase in a like period preceding the 

visits of inspectors amounted only to 12,000/., or very little more than 

a quarter per cent (0°28). 

Coal is produced in thirty of the departments of France. There are 
in these 258 mines in operation, giving employment to 21,913 workmen. 

The quantity raised in 1814 was 665,000 English tons. Double that 
quantity was raised in 1825. In 1832, before the plan of inspection 
was adopted, the produce was 1,600,000, and in 1836 was raised to 
2,500,000 tons. 

There are iron-works in sixty out of the eighty-six departments of 
France. The number of works in 1836 was 894, and of workmen 15,738: 
the product, 303,739 English tons of pig-iron, and 201,691 tons of bar- 
iron, valued at 3,580,000/. Taking into account the further processes 
connected with this branch of industry, the total value created was in 
1836, 4,975,000/., and the workmen were 43,775. In 1824 the quan- 
tity of pig iron made was 194,636. In 1832 (the year preceding in- 
spection), 221,660 tons, and in 1836, 303,739 tons. 

Some further particulars as to the modes of manufacture were given, 
and slight notices of other branches of mining industry. It appears 
that, taken in its full extent, this class of employment gives support to 
273,364 workmen, the value of whose labour is 15,100,000/.; this in- 
cludes the produce of stone-quarries, salt-works, glass-works, pottery, 
and various chemical products having a mineral origin. 


On the Statistics of Vitality in Cadiz. By Colonel Syxes. 
From this elaborate memoir the following are extracts : 
Population.—Cadiz has 4 parishes within the walls and 1 outside, 

and for police and municipal objects it is divided into 12 barriers or 
districts. These barriers comprise a population of 58,525 souls, agree- 
ably to the census of December last, the males being 27,301, and the 
females 31,224. 


TRANSACTIONS OF THE SECTIONS. 175 


Census of Cadiz, as the same stood on the 1st of December, 1837. 


nnn aa el 


Quarters or Parishes. Districts. Males. | Females. Total. 
1 fe Wl las Escuelas . . . 2,306 2,780 5,086 
| No. 1. Santa Cruz 2.DelPopulo .... 2,208 2,235 4,443 
- 3. Dela Merced. . . . 4,203 4,327 8,530 
4,DeSan Carlos .. . 392 510 902 
2. Rosario . 5. De San Francisco . . 1,321 1,375 2,696 
6. Del Correo . .. . 1,749 1,993 3,742 
7. De la Constitucion . . 2,235 2,590 4,825 
3. St. Antonio 8. Del Hercules .. . 2,072 2,842 4,914 
9.Delas Cortes. . . . 1,410 1,927 3,337 
4 10.DelaPalma. ... 2,514 2,519 5,033 
4. St. Lorenzo 11. Del Hospicio. . .. 3,386 3,861 7,247 
12.Dela Libertad . .. 2,833 | 3,709 6,542 
Parish outside of the Walls. 672 556 1,228 
27,301 | 31,224 | 58,525 


From the tables of Burials are deduced the following results, mani- 
festing even in a more marked manner than kn other countries, the 
excess of mortality amongst males, whether adults or children, over 


females. 
Total Annual ‘ 
Deaths. ener Per Cent. of Deaths. 
In 38 years the total deaths were ...... 110,345| 2640 f £51, 51, or linevery 22°13 


inhabitants! 


4°31, or 1 in every 23:2 
85,786) 2523 inhabitants. 


In 34 years, striking out the 4 eer: { 
Tn the 4 years of yellow fever .......+. 24,559| 2903 { 4-96, or 1 in every 20 


Of yellow fever .....sseceeeeseenees 


inhabitants nearly. 
3°98, or 1 in every 25:07 


Average of last 15 years, no yellow 35,007| 2334 


fever ....... paadssthandscMMubneseaead inhabitants. 

For the year 1837-8 ssscsssessesseeerees 2,958| 2958 |{ 3'86,or lin every 25-91 

> inhabitants. 

Children for 38 years...scsssessessesseers 42,554) 1119 | 4.3896, or 1 in every 2°99 

Proportion of children to the whole { 47-08, or Lin every 2:12 
deaths, 1837-8......ccscesceceeeceeees a a 1 deaths. 

For the first 25 years, the deaths of 81,007 35:77, or 1 in every 2°79 
men to the whole deaths..........+. . e deaths. 

Ditto of Women to the whole deaths.) $1,007]... ieee eta every (7 

Ditto of boys to the whole deaths...... 81,007)... pga Seas 

Ditto of girls to the whole deaths ...| 81,007} ... Se pean eve 

For 1837-8, the male deaths to the 4-25, or linevery 23°49 
male population of 27,301 were... oo es males living, 

For 1837-8, the female deaths to the 3:51, or lin every 28°48 
female population of 31,224 were i 4 females living. 

For 1837-8, the deaths of men to the 24-62, or 1 in every 4:06 
whole deaths ......secsseseeseneeeees a ca: deaths, 

For 1837-8, the deaths of women to 28°34, or 1 in every 3°53 
the whole deaths........ssceseseeeves “es il deaths. 

For 1837-8, the deaths of boys to the 26-83, or 1 in every 3°72 
Whole deaths ...,....eseessesseecerees h ay deaths. 


deaths, 


For 1837-8, the deaths of ae to] 20-25, or 1 in every 4:94 
the whole deaths...ersssssesseessees SAT epee aay { 


176 EIGHTH REPORT—1838. 


The next subject is the Parochial Returns of Births, Deaths, and 
Marriages. 


Average of the Annual Births, Marriages, and Deaths, in the different 
Parishes of Cadiz, from the year 1827 to 1836 inclusive. 


_ BIRTHS. | far. DEATHS. 

———_————_ friages. | ———— 

Boys. | Girls. Men. |Women.| Boys. | Girls. 

Parish of Santa Cruz ........ 250°8 | 238-9 | 127-3 |113°8 | 132:0 | 83:4 | 766 
Parish of the Rosary........+ 1061 | 93-4 | 45-1 | 48:0 | 54:6 | 18:5 | 186 
Parish of St. Antonio ....... 102:4 |103°8 | 55-9 | 90-4 | 83-7 | 16:9 | 19:4 
Parish of St. Lorenzo ....... 258:9 |239°7 | 97-5 |105°8 | 156-4 | 98-6 | 88:4 
Parish of Castrense .........| 29°3 | 28:3 9-1 | 12:9 8:3 46 2-9 

Parish of St. Joseph with- : ie : i : : ‘ 

out the walls ........00. } 21:0 | 185 v7 | 102 95 Mg ue 
Total annual average...| 768°5 | 722-6 | 342°6 | 381-1 | 444-5 | 229-9 | 213-1 


1491-1 825°6 443 
es 
1268°6 
Absolutely buried in the Cemetery.....sssssessesssssereseeee I Oa "2 858 
UY 
2190-2 
EDUCATION. 


Return of the Establishments for Education in Cadiz, distinguishing Day 
Scholars from Boarders and Males from Females, January, 1838. 


ESTABLISHMENTS. DAY SCHOLARS. BOARDERS. 
Colleges, | Schools, Cg Rests 2) Males, | Females. Males. | Females. 
2 Age tse ae 189 mae 81 
. 29 a 2, 1,989 a 12 
tee 43 ae 16 1,030 eee 4 
tes 20 37 167 1 
Total ...|| 2,231 1,197 93 5 
Total ... 2,324 | 1,202 
uY___+,,—_— 
Total Males and Females......... 3,526 


The total number of children attending schools being 6:02 per cent. 
of the population, or one in every 16°51 inhabitants ; and supposing the 
children between 5 and 15 years of age to be 25 per cent. of the popu- 
lation, or 14,631, the per-centage receiving instruction is only 1 in 
4°13, or 24°1 per cent.——a proportion much below the lowest averages 
yet ascertained in England, as Liverpool 47} per cent., and New- 
castle 513 per cent. But the 455 poor children receiving instruction 


TRANSACTIONS OF THE SECTIONS. . 177 


in the Hospicio are to be added, and this will slightly improve the 
averages ; making the number of children educated 27-2 per cent., or 
1 in every 3°70. 


On an Outline for Subjects for Statistical Inquiries. By Mr. Hare, 
President of the Leeds Statistical Society. 


The author observed how much the importance and value of statistical 
societies would be augmented by a strict attention, so far as is practi- 
cable, to uniformity in the designs they have in view, by a general agree- 
ment in reference to the principles on which they are based, the terms 
and numerals employed in their investigations, and the documents ne- 
cessary to their elucidation. 

With a view to the attainment of these desirable objects, Mr. Hare 
has sketched an outline of the subjects of inquiry, comprising a series 
of tables, intended to be filled up by different societies. ¥ 
_ From such tables, of which there are upwards of 120, each town 

where a society is established may have the number and description of 
papers which its peculiar locality may require. 


Criminal Returns of the Empire. By Jerrries KIncsey. 


The author presented, in this communication, a summary of criminal 
_ returns according to the system of fiscal and criminal statistics as pro- 
pounded by himself in the Standard County Book for the treasurers 
of Irelond. The subjects were arranged under the following heads :— 
Statistical references. Population census, 1831. Number of souls to 
the square mile, English. Comparative standard: Carlow, least popu- 
lous county, rated as one crime. Counties in the order of population. 
_ Offences against the person. Offences against property with violence. 
Offences against property without violence. Offences (malicious) 
against property. Offences and forgery against the currency. Offences 
not included in the foregoing. Total of all offences. Deaths. Free 
pardon. Executed. Petty Sessions’ courts. General Sessions’ courts. 
_Assize courts. 

__ The return to these several heads was collected from the Prison 
Reports, Ireland, for 1836; but, seeking to establish a principle, the 
author did not hold himself responsible for the accuracy of the parti- 
-eulars which were stated in the return. 


VOL. Vil. 18538. N 


” 


INDEX I 


TO 
REPORTS ON THE STATE OF SCIENCE. 


Oszsects and Rules of the Asso- 
ciation, v. 

Officers and Council, viii. 

Places of Meeting and Officers from 
commencement, ix. 

Members of Council from commence- 
ment, x. 

Officers of Sectional Committees at 
the Newcastle Meeting, xii. 

Treasurer’s Account, xiv. 

Reports, Researches, and Desiderata, 
Xv. 

Synopsis of sums appropriated to sci- 
entific objects, xxvii. 

Arrangement of the General Evening 
Meetings, xxx. 

Address, by Mr. Murchison, xxxi. 


Anemometer, Whewell’s, observa- 
tions at Devonport made with, 28. 


Bristol and English Channels, ac- 
count of leveling operations be- 
tween the, 11. 

British Islands, magnetic survey of 
the, 49. 

Bunt (Mr.) account of a level line, 

_ measured from the Bristol Channel 
to the English Channel by, 1. 


Committee for the Liverpool Obser- 
vatory, report of the, 316. 

Committee on the sounds of the 
heart, 317. 


Fox (R. W,), magnetic observations 
by, 76, 89, 101, 147. 


Gases present in atmospheric air, de- 
tection and measurement of, 316. 


Harris (W. 8.), account of the pro- 


gress and state of the meteorolo- 
gical observations at Plymouth, 21. 


India, desiderata required in, xxii. 
Ireland, on the magnetic isoclinal 
and isodynamic lines in, 91, 165. 
Iron, on the action of sea and river 

water upon, 253. 


Johnson (Capt.), magnetic observa- 
tions by, 59. 


Lardner (Dr.), report on the deter- 
Mination of the mean numerical 
values of railway constants, 197. 

Leveling staff and vane, sketch of a, 
18. 

Level line, measured from the Bristol 
Channel to the English Channel, 
account of a, 1. 

Lloyd (Prof.) on the magnetic survey 
of Ireland, 91, 165. 

—, magnetic observations in Eng- 
land, 67, 138. 


Magnetic intensity, on the variations 
of the, 318. 

Magnetic survey of Great Britain, 
49. 

Magnetical observations, reeommend- 

ations for, xxii. 

Mallet (R.), report of experiments 
on the action of sea and river wa- 
ter upon cast and wrought iron, 
253. 

— onthe action of heat oninorganic 
and organic substances, 313. 

Meteorological observations at Ply- 
mouth, progress and state of the, 
21. 

Mining records, proposed establish- 
ment of a depository for, xxiii. 

Murchison (R. I.), his address, xxxi. 

wn 2 


180 


Ordnance survey, xxiii. 
Organic and inorganic substances, 
action of heat on, 313. 


Phillips (Prof.), magnetic observa- 
tions by, 70, 144. 

Plymouth, account of the meteorolo- 
gical observations at, 21. 


Railway constants, on, 197. 

Researches, specific, involving appli- 
cations to Government or public 
bodies, xxi. ; involving grants of 
money, Xxiy. 

Researches, special, notices of pro- 
gress in, 315. 

Ross (Capt.), magnetic observations 
by, 74, 86, 116, 148, 157, 174, 
182. 


INDEX II. 


Sabine (Major), memoir on the mag- 
netic isoclinal and isodynamic lines 
in the British Islands, 49. 

on the variations of the mag- 
netic intensity, 318. 

Scotland, magnetic observations in, 
86, 155. 


Tides, report on the discussions of, 19. 


Water, its action on iron, 253. 


West (W.) on the detection and mea- 


surement of gases present in at- 
mospheric air, 316. 

Whewell (Rev. W.), report on a level 
line, measured from the Bristol 
Channel to the English Channel, 1. 

, Teport on the discussions of 

tides, 19. 


INDEX I. 


TO 


MISCELLANEOUS COMMUNICATIONS TO THE 
SECTIONS. 


Asiges and Pinus, on the genera, 
117. 

Abscess of the lungs, on, 134. 

Acid, gambodic, 60. 

Acoustic instrument, improved, 129. 

Acrodus nobilis, the extinct genus, on 
the teeth of, 138. 

Actiniz, on the gemmiferous bodies 
and vermiform filaments of, 113. 

Adams (Dr.) on peat-bogs, 95. 

, on the placental souffle, 123. 

Addams (R.), apparatus for solidify- 
ing carbonic acid, 70. 

Air, the amount required for respira- 
tion, 131. 

Airy (G. B.) on correcting the local 
magnetic action of the compass in 
iron steam-ships, 21. 

Alcohol, on the products obtained by 
the action of nitric acid on, 55. 

Allen. (Capt. W.) on the probability 


of the river Tchadda being the out- 
let of the Jake Tchad, 99. 

Allis (T.) on the toes of the African 
ostrich, 107. 

Alston Moor, on the mountain lime- 
stone formation in, 79. 

America, North, on the climate of, 
29; geology and thermal springs of, 
gl. 


ennai carbonate of, on the con- 
stitution of, 63. 

Andrews (Dr.) on the influence of 
voltaic combination on chemical 
action, 69. 

Anthracosis in a lead miner, case of, 
130. 

Arch, oblique, on the, 152. 

Ardea alba, on the, 106. 

Arsenic, vapour of, specific gravity of, 
64. 

Ascaris alata, 115. 


eats 


INDEX II. 


Atmospheric pressure, ‘mode of ob- 
taining an increase of, 73. 

Austen (R. C.) on geological evidence 
and inferences, 93. 


Babbage We ) on engravings on $i0d, 
154, > 

Babington (C. C.)'on the botany of 
the Channel Islands, 117. 

Bache (Prof.) on the effect of de- 
flected currents of air‘on the quan- 
tity uf rain collected by a rain- 
gauge, 25. 

Backhouse (E.) on the annual ap- 
pearance.on the Durham coast’ of 
some of the Lestris tribe, 108. 

Baer (Prof.) on the frozen soil of Si- 
beria, 96. 

—-, sketch of the Russian expedi- 
tions to Novaia Zemlia, 96. 

Bannester (S.) on the population of 
New Zealand, 167. 

Barbel, on the pharyngeal tooth of 
the, 143. 

Barnes (Dr.) on abscess of the lungs, 
134. 

Barometrical instrument for travellers 
in mountainous districts,:37. 

Bellingham (Dr.) on the occurrence of 
crystals inthe human intestines, 134. 

Berwick coal-field, on the, 76. 

~Bicyanide with binoxide of mercury, 
a new compound of, 59. 

Bird (Dr. G.) on some of the products 

. obtained by the action of nitric acid 
on alcohol, 55. 

on the artificial formation of a 

' basic chloride of copper by voltaic 
influence, 56. 

— on the deposition of metallic 
copper from its solutions, 57. 

Blackwall (T. E.) on the production 

_ + of crystals of silver, 74. . 

_ Blake (J.) on the action of substances 

- injected into the veins, 129. 

Botany, 116. 

_ Bowring (Dr.) on Plagne ‘and ’ qua- 
rantine, 120. 

Brady pus didactylus, 145.'- 

Breunner (Count) on the use‘of wire 
ropes in deep mines, 150. 

Brewster (Sir. D.) on an Beale par- 
allax in vision, and on the law of 
_ visible direction, 7. 

on a new phenomena of colour in 

certain specimens of fluor spar, 10. 


181 


Brewster (Sir D.) on new phenomena 
of diffraction, 12. 

on ‘some’ preparations of’ ‘the 

eye by Mr. Clay Wallace, 14. 

on the ‘combined’ action of 

grooved metallic and oveeperent 

surfaces upon light, 13) 

on a new kind of polarity in ho- 

mogeneous light, 13. 

on the fossil teeth of the Sauroid 
fishes, 90. 

Bridges, oblique, on, 152. 

Bridges oftimber, onconstructing, 150. 

Brine-spring, carbonic acid gas emit- 
ted by a, 28. 

Brisbane (Sir Thos. M.) on the dif- 

’ ference of longitude between Lon- 
don and Edinburgh, 20. 

Buddle (J.) on the Newcastle coal- 
field, 74. 


Cadiz, statistics of vitality in, 174. 

Carbon, specific gravity of the vapour 
of, 64. 

Carbon and hydrogen, a new com- 
pound of, 72. 

Carbonate of ammonia, commercial, 
on the constitution of, 63. 

Carbonic acid, on solidifying, 70. 

Carbonic acid gas emitted by a brine- 
spring, 28. 

Carcharias Megalodon, 141. 

Cargill (Mr.) on educational statistics 
of Newcastle, 165. 

Carlisle; on the red sandstone of,'78. 

Cape of Good Hope, observations on 
stars and nebule at, 17. 

Cattle, wild, of Chillmgham Park, on 
the, 100. 

Caustic potass, chemical action of 
light on, 61. 

Cefn cave, on the remains found in, 87. 

Channel Islands, on the botany of the, 
117. 


Charlton (Dr.) on Tetrao Rakelhahn, 


107. 
Charlton (W. H.), statistics of Bel- 
lingham in Northumberland, 168. 


' Cheddar, Somersetshire, description 


of a cave at, 85. 
Cheirotherium, its footsteps in the 
stone quarries of Storeton Hill, 85. 
Chemical action, influence of voltaic 
combination on, 69. 
Chemical combinations, on, 68. 
Chemistry, 39. 


182 


Cheshire, statistics of the working 
classes in, 172. 

Chevallier (Rev. T.) on the computa- 
tion of heights by the barometer, 38. 

Chillingham Park, on the wild cattle 
of, 100. 

Chimera, on the tooth of the, 140. 

Chloride of copper, basic, artificial 
formation of, 56. 

Chlorine, specific gravity of, 64. 

Cholera, on Mr. Farr’s law of recovery 
and mortality in, 126. 

Clarke (W. H.) on a fish with four 
eyes, 110. 

Classification of insects, on the, 113. 

Cliff’s dry gas meter, on, 158. 

Climate of North America, on the, 29. 

Coal-field of Newcastle, 74. 

of Berwick and North Dur- 
ham, 76. 

Coal gas the cheapest fuel for cooking, 
159, 

Coathupe (C. T.) on the blue pigment 
of Dr. Traill, 61. 

Collieries’ Club of Darton, account of 
the, 173. 

Colour in fluor spar, new phenomena 
of, 10. 

Coluber natrix, 116. 

Comet, Halley’s, 19. 

Cook (J. C.) on the genera Pinus and 
Abies, 117. 

Cooking, coal-gas the cheapest fuel 
for, 159. 

Copper, basic chloride of, its artificial 
formation, 56. 

Copper, metallic, on the deposition 
of, 57. 

Crawford (Dr.) case of anthracosis in 
a lead miner, 130. 

Crystals, on the propagation of light 
in, 6. 

— in the human intestines, 134. 

of silver, on the production of, 74. 

Cuzcoin Peru, position of thecity of, 99. 


Dalziel (Dr.) on sleep, and an appa- 
ratus for promoting artificial respi- 
ration, 127. 

Daubeny (Dr.) on the climate of North 
America, 29. 

on the geology and thermal 
springs of North America, 91. 

Dawes (J. S.) on the manufacture of 
iron, 68. 

Dead Sea, on the water of, 73. 


INDEX [f. 


Deafness, an improved acoustic in- 
strument for, 129. 

Dent (E. J.) onthe effects of tempera- 
ture on the regulators of time- 
keepers, and-improvements in pen- 
dulums, 35. 

Derbyshire, on the position of the 
rocks of the Penine chain in, 79. 
Diabetes, on the sugar of urine of, 43. 

Dictyodus, 142. 

Diffraction, on new phenomena of, 12. . 

, when produced by a transparent 
diffracting body, 12. 

Diluvial drift, containing shells and 
remains of animals, 86. 

Dobson’s (Mr.) method of making 
bricks of any colour, 163. 

Durham, statistics of nine collieries 
in, 169. 

— coal-field, on the, 76. 


Educational statistics of Newcastle, 
165. 

Ehrenberg’s (Prof.) microscopical dis- 
coveries, 116. 

Emulsin, on, 48. 

Encrinus moniliformis, monstrosities 
of, 115. 

Eugene Aram, on the skull of, 125. 

Euphrates, on the recent ascent of 
the, 99. 

Exley (Rev. T.) on the specific gravi- 
ties of nitrogen, oxygen, hydrogen, 
and chlorine, and also of the va- 
pours of carbon, sulphur, arsenic, 
and phosphorus, 64. 

— on chemical-combinations, 68. 

Eye, Mr. Clay Wallace’s preparations 
of the, 14. 

of the shark, structure of the vi- 

treous humour of, 15. 


Fairbairn (W.) on the manufacture of 
steam-engine boilers, 160. 

Falcons of Greenland and Iceland, on 
the, 106. 

Farr (Mr.) on his law of recovery and 
mortality in cholera, 126. 

Felkin (W.), statistics of the working 
classes in Hyde, Cheshire, 172. 

Filtering water, methods of, 163. 

Fish, structure of the teeth of, 137. 

with four eyes, 110. 

Fishes, osseous, 110. 

Fiuor spar, new phenomena of colour. 
in, 10. 


Forbes (Prof.) on a brine-spring emit- 
ting carbonic acid gas, 28. 

_ Forbes (E.) on the terrestrial Pulmo- 
nifera in Europe, 112. 

Fourness (Mr.) on coal-mine ventila- 

i tion, 163. 
Fox (R. W.) on the production of a 
horizontal vein of carbonate of zinc, 
90. 

France, progress and amount of mining 
industry in, 174. 

Fuel, plan for cementing together 
small coal and coal dust for, 85. 


Gamboge, on the resin and compounds 
of, 60. 

Garnett (J.) on a new day and night 
telegraph, 159. 

Gas, olefiant, some experiments on, 
40. 

- Gas meter, on Cliff’s, 158. 

Geography, 96. 

Geological evidence and inferences, 
on, 93. 

Geological models, on the construc- 
tion of, 94. 

Geometric method, general, 1. 

Geology, 74. 

_ Glover (R. M.) on the functions of 
the rete mucosum and: pigmentum 
nigrum, in the dark races of man- 
kind, 125. 

Goodsir (Mr.) on the human teeth, 

; 121. 

Glynn (J.) on the water-works of 
Newcastle-on-Tyne, 164. 

Goliathus, new species of, 113. 

Goniometer, Wollaston’s, on an alter- 

ation in, 153. 

Granville (Dr.) on an improved ste- 

thoscope, 129. 

Graves (C.) on a general geometric 

method, 1. 

Gray (J. E.) on the angular lines on 
-shells of certain mollusca,, 1l. 

— on a new British shell, 110. 

_ ——- on the boring of pholades, 111. 

: on the wombat, 111. 

_ Green (B.) on an improved principle 
inthe constru ction of timber bridges, 
150 

Caster (W.).on the construction of 
steam-boilers, 162. 

: _ Greenhow (T. M.) on the beneficial 

effects of mercurial action rapidly 

induced, 124. 


INDEX II. 


183 


Greenhow (T. M.) on fractures, 130. 
Griffith (R.) on the geological struc- 
ture of the south of Ireland, 81. 
Gyrodus, on the teeth of the genus, 

143. 


Hemadynameter, 129. 

Hall (Mr.) on a machine for raising 
water by an hydraulic belt, 158. 

Halley’s comet, on, 19. 

Hamilton (Sir W. R.) on the propa- 
gation of light im vacuo, 2. 

on the propagation of light in 
crystals, 6. 

Hancock (J.) on the Greenland and 
Iceland falcons, 106. 

Handyside (Dr.) on the Sternoptixi- 
nee, 110. 

Hare (Dr.), some chemical experi- 
ments, by, 39. 

Hare (Mr.) on statistical inquiries, 
Vide 

Hawkins (J. T.) on methods of filter- 
ing water, 163. 

Hawthorn (Mr.) on an improved me- 
thod of working the valves of a lo- 
comotive engine, 160. 

Helm wind, on the, 33. 

Herapath (W.) on a new process for 
tanning, 71. 

Herschel (Sir J. W. F.) on the vi- 
treous humour of the eye of ashark, 
15. 

——., observations on stars and ne- 
bule at the Cape of Good Hope, 
17. 

— on Halley’s comet, 19. 

Hincks (Rev. W.) on vegetable mon- 
strosities, 120. 

Hindmarsh (J.) on the wild cattle of 
Chillingham Park, 100. 

on the condition of the agricul- 
tural labourers of Northumberland, 
167. 

Hodgkinson (E.) on the tempera- 
tures observed in mines in Cheshire, 


34. 

Hope (Rev. F. W.) on the modern 
classification of insects, 113. 

on the noxious insects which in- 
jure the apple trees and hops, 113. 

Hydrogen gas, an attempt to liquefy, 
73. 

Hydrogen, specific gravity of, 64. 

Hydrogen and carbon, a new com- 
pound of, 72. ; 


184 


Hydrogen and oxygen, combination 
of, 68. 


‘Inglis (Dr.) on the skull of Eugene 
Aram, 125. 
Insects, on the modern classification 
of, 113. 
Intestines, human, occurrence of cry- 
stals in, 134. 
Iodides, medicinal and poisonous pro- 
perties of the, 123. 
Ireland, geological structure of the 
southern counties of, 81. 
—, report of the railway commis- 
sioners in, 171. 
Iron, on an improvement in the ma- 
nufacture of, 68. 
, on foreign substances in, 41. 
Isograph, a new instrument, 155. 
Isometrical projection, instruments to 
facilitate the process of, 155. 
protractor, 155. 
Isomorphism, exceptions to the lawof, 
59. 


Jenyns (Rev. L.) on certain species of 
Sorex, 104. 

Jervis (Major) on the trigonometrical 
survey of India, 98. 

Johnston (Prof.) on the origin of pe- 
troleum, 60. 

on the law of isomorphism, 59. 

on a new compound of sulphate 

of lime with water, 59. 

on anew compound of bicyanide 

with binoxide of mercury, 59. 

on Middletonite, 60. 

on the resin of gamboge and its 
compounds, 60. 

Jones (Rev. H. L.), statistics of the 
Universities of Oxford and Cam- 
bridge, 170. 

Jukes (J. B.) on the position of the 
rocks of the Penine chain of Derby- 
shire, 79. 


Kingsley (J.) on criminal returns of 
the empire, 177. 


Lang (Mr.) on improvements in ship- 
building, 157. 

Lead, native diarseniate of, 46. 

——, on the extraction of silver from, 
50. 

Leithart (J.) on the stratification of 
rocks, 88. 


INDEX IT. 


Leithart (J.) on faults, and anticlinal 
and synclinal axes, 89. 

Lepidotus, on the teeth of some of tlie 
species of this genus, 142. 

Leveling stave, an improved, 154. 

Light, on its propagation in vacuo, 2. 

——,, on its propagation in crystals, 6. 

, on some points connected with 

the theory of, 6. 

, action of grooved and trans- 

parent surfaces upon, 13. 

, homogeneous, a new kind of po- 
larity in, 13. 

——., on its chemical action in the de- 
coloration of recent solutions of 
caustic potass, 61. 

——, on the blackening of nitrate of 
silver by, 63. 

Lime, sulphate of, with water, on a 
new compound of, 59. 

Locomotive engine, improved method 
of working the valves of a, 160. 
London and Edinburgh, difference of 

longitude between, 20. 

Long (Mr.), description of a cave at 
Cheddar, 85. 

Longitude between London and Edin- 
burgh, difference of, 20. 

Lunar volcanos, on, 93. 

Lungs, on abscess of the, 134. 

Lycopodium lepidophyllum, on, 119. 

Lyell (C.) on vertical lines of flint, 
& 


Lynch (Lt.) on the recent ascent of 
the river Euphrates, 99. 


McAlister (Rev. J.), statistical notices 
of the blind asylum, 167. 

McDowall (P.) on the statistics of 
Ramsbottom, 168. 

Magnet-clectrometer, experiments on 
a, 74. 

Magnetic action of thecompass in iron 
steam-ships, on correcting, 21. 

Mallet (R.) on the chemical action of 
light in the decoloration of recent 
solutions of caustic potass of com- 
merce, 61. 

Mandingo, brief account of a, 97. 

Marsupiata, on, 105. 

Maule (Mr.) on a substitute for the 
forcing-pump in supplying steam- 
boilers, 163. 

Mathematics and physics, 1. 

Maugham (W.) ona new compound 
of carbon and hydrogen, 72. 


_ Maugham (W.), on obtaining an in- 

crease of atmospheric pressure, 73. 

_ Mechanical science, 150. 

Medical science, 120. 

_ Megatherium, on the structure of the 

tooth of the, 146. 

_ Mercury, binoxide of, and bicyanide, 

_ anew compound of, 59. 

_ Mercury, new salts of, 72. 

Metropolis, on the number of fires in 
the, 170. 

_ Mexico, on the government map of, 

98. 

_ Microscopical discoveries, 116. 

_ Middletonite, on, 60. 

_ Miller (W. H.) on Wollaston’s gonio- 

: meter, 153. 
Milne (D.) on the Berwick and North 

Durham coal-fields, 76. 

_ Mines, on the use of wire ropes in, 
150. 

Mining industry in France, progress 
and amount of, 174. 

Mining records, importance of pre- 

___ serving, 156. 

_ Models exhibited, 163. 

_ Mollusca, on the distaibutinn: of, 112. 

Morren (Prof. ) on the production of 
vanilla in Europe, 116. 

_ Morrison (Lt.) on the magnet-electro- 
meter, 74. - 

Mortimer (J.) on a fish with four 

eyes, 110. 

_ Motella cimbria, of Linnzus, 109. 

Motley (T.) on the construction of a 

' railway with cast-iron sleepers, 

157. 

on a suspension bridge over the 
Avon, 157. 

Murchison (R. I.) on the Silurian sy- 

- stem of strata, 80. 

Murray (J.) on the water of the Dead 

Sea, 73. 

a Myliobatis, on the teeth of the, 138. 


Nerves, on the functions of the eighth 
pair of, 124. 

leweastle, educational statistics of, 
- 165; on the church- and chapel- 
9 room in All Saint’s parish, 166; 
- afreturn of prisoners in, 166; on 
the water-works of, 164 ; statistical 
notices of the blind asylum, 167. 

| Newcastle coal-field, 74. 

| Nicholson (P.) on the oblique arch, 
152.,. 


INDEX II. 


185 


Nitrate of silver, as a caustic and the- 
rapeutic agent, 132. 

, blackened by light, 63. 

Nitric acid, on the products obtained 
by its action on alcohol, 55. 

Nitrogen, on the specific gravity of, 
64. 

Norwich, on vertical lines of flint in 
the chalk near, 87. 

Novaia Zemlia, Russian expeditions 
to, 96. 


Oblique arch, on the, 152. 

Odontograph, on the, 154. 

Oran (Mr.) on cementing small coal 
and coal dust for fuel, 85. 

Organic remains, antiquity of, 95. 

Ostrich, African, on’ the toes of the, 
107. 

Owen (Prof.) on the structure of the 
teeth, 135. 

on Marsupiata, 105. 

Oxygen gas, an attempt to liquefy, 77. 

Bie: and hydrogen, combination of, 

8. 
—, specific gravity of, 64. 


Pagellus acarine, 109. 

Parnell (R.) on some new and rare 
British fishes, 109. 

Pattinson (H. L.) on the extraction of 
silver from lead, 50, 

Peat bogs, on, 95. 

Pendulums, improvements in, 35. 

Pentland (J. B.) on the position of the 
city of Cuzco, 99. 

Petroleum, on the origin of, 60. 

Phillips (R.) on a blue pigment, 60. 

Pholades, on the boring of, 111. 

Phosphorus, specific gravity of the 
vapour of, 64. 

Pigment, blue, on a, 60, 61, 

Pinus and Abies, on the genera, 117. 

Plague and quarantine, on, 120, 

Platinum, the combination of hy- 
drogen and oxygen effected by, 68. 

Polyodon folium, 116. 

Porter (G. R.) on the progress and 
present amount of mining industry 
in France, 174. 

Portlock (Capt.) on the Silurian rocks 
in Tyrone, 84. 


| Potass, caustic, chemical. action of 


light in the decoloration of recent 
solutions of, 61. 


Powell (Prof.) on the theory of light, 6. 


186 


Price (J.) on an improved method of 


constructing railways, 158. 

on. a steam-engine boiler, 162. 

Psalidognathus Friendii, 113. 

Psammodus, on the teeth of the 
genus, 140. 

Ptychodus latissimus, onthe structure 
of the tooth of, 140. 

Pulmonifera, terrestrial, on the distri- 
bution of, 112. 


Raia chagrinea, 109. 

intermedia, 109. 

Railway with cast-iron sleepers, on 
the construction of a, 157. 

Railways, improved method of con- 
structing, 158. 

Rain, variations in the quantity of, 27. 

Rain-gauge, effect of deflected currents 
of air on, 25. 

Ramsbottom, statistics of, 168. 

Rats, pouched, 105. 

Rawson (W. R.) on the number of 
fires in the metropolis, 170. 

———, report of the railway commis- 
sioners in Ireland, 171. 

Rees (Dr. G. O.) on the Liquor 
Amnii, 126. 

Reid (Lt.-Col.) on the law of storms, 


21. 

Reid (Dr. D. B.) on the amount of 
air required for respiration, 131. 
Reid (Dr. J.) on the functions of the 

eighth pair of nerves, 124. 
Reptiles, on the teeth of, 144. 
Resin of gamboge, and its compounds, 


Respiration, amount of air required 
for, 131. 

—~, cause of the sound of, 122. 

——, artificial, apparatus for pro- 
moting, 127. 

Richardson (Dr. J.) on pouched rats, 
105. 

Richardson (T.) on eniulsin, 48. 

——., examination of sphene, 49. 

Robison (Sir J.) on a barometrical 
instrument for travellers in moun- 
tainous districts, 37. 

Rocks, on the stratification of, 88. 

Rowley (S.) on a new rotatory steam- 
engine, 162. 

Russell (J. S.) on the resistance of 
water, 163. 


Salts of mercury, new, 72 


INDEX II. 


Samuda(Mr-.) on Cliff’s dry gas meter, 
158. 

Sauroid fishes, on the fossil teeth of, 
90. 

Scanlan (Mr,) on the constitution of 
the commercial carbonate of am- 
monia, 63. | 

on the blackening of nitrate of 
silver by light, 63. 

Shell, new British, 110. 

Shells of mollusca, on the annular 
marks on, 111. 

Ship building, on improvements in, 
157: 

Siberia, on the frozen soil of, 96. 

Silver, crystals of, on the production 
of, 74. 

, hew process for its extraction 

from lead, 50. 

, nitrate of, blackened by light, 63. 

Silurian system of strata, on the, 80. 

rocks in the county of Tyrone, 


84. 

Sleep, on, 127. 

Smelt, on a new species of, 108. 

Smith (J.) on the shells of the newer 
pleiocene deposits, 87. 

Smith (Dr.W. )on the variations in the 
quantity of rain in different parts of 
the earth, 27. 

Sopwith (T.) on the mountain lime- 
stone formation in Alston Moor,79. 

—— on the construction of geological 
models, 94. 

— on an improved leveling stave, 
154. 

——, description of instruments to fa- 
cilitate the process of isometrical 
projection, 155. 

on improved writing-cabinets, 

156. : 

on the importance of preserving 

national mining records, 156. 2 

Sphene, examination of, 49. 

Spittal (Dr.) on the cause of the sounds 
of respiration, 122. 

Statistics, 165. 

-Steam-boilers, a substitute for the 
forcing-pump in supplying, 163. 
Steam-engine boiler, on a, 162; on 

the manufacture of, 160; on the 
construction of, 162. ¥ 
Steam-ships, iron, on correcting the 
local magnetic action of the compass — 

in, 21. 
Sorex, on certain species of, 104. 


q INDEX 11. 


Sowerby (G. B.) on certain monstro- 


- sities of Encrinus moniliformis, 115. 


on Lycopodium lepidophyllum, 


genus, 142. . 
Stereoscope, Wheatstone’s, 16. 
Sternoptix, on new species of the 
genus, 110. 

Stethoscope, improved, 129. 

Stevens (J.), a return of prisoners in 
Newcastle, from Oct. 2, 1837, to 
Aug. 2, 1838, 166. 

_ Storms, on the law of, 21. 

Strickland (A.) on a species of Scyl- 

 tium, 107. 4 

on the Ardea alba, 106. 

Sugar, diabetic, on, 43. 

_ Sulphate of lime with water, on anew 

compound of, 59. 

Sulphur, specific gravity of the vapour 
of, 64 

Suspension-bridge over the Avon, on 
a, 157. 

_ Sykes (Lt.-Col.) on a rare animal from 

South America, 104. 

on the statistics of vitality in 

Cadiz, 174. 


119. 
| Spherodus, on the teeth of the extinct 


_ Tanning, a new process for, 71. 
_ Tchadda river, the outlet of the lake 
__ Tchad, 99. 

Teale (T. P.) on the gemmiferous 
: bodies and vermiform filaments of 
_ Actinie, 113. 
Teeth, human, origin and development 

of the, 121. 

, on the structure of the, 135. 

, fossil, of the Sauroid fishes, 90. 
_ Telegraph, new, 159. 

Temperature, its effect on the regula- 

tors of time-keepers, 35. 

_ Tetrao Rakelhahn, on, 107. 
_ Thermal springs of North America, 91. 
Thomson (Dr. A. T.) on the medicinal 
and poisonous properties of the io- 

 dides, 123. 

Thomson (Dr. R. D.) on Mr. Farr’s 
law of recovery and mortality in 
cholera, 126, 

— on nitrate-of silver as a caustic 
__and therapeutic agent, 132. 
Thomson (Dr. T.) onthe foreign sub- 

stances in iron, 41. 
on the sugar in urine of diabetes, 


43, 


187 


Thomson (Dr. 1.) on native diar- 
seniate of lead, 46. 

on emulsin, 48. 

Tipula Tritici, 113. 

Torbock(R.), mode of arresting uterine 
hemorrhage, 133. 

Toxodon, 147. 

Trimmer (J.) on diluvial drift con- 
tainingshellsand remains of animals 
in Cefn Cave, 86, 

Turner (J. A.) on a new species of 
goliathus and some Lucani, 113. 


Uterine hemorrhage, mode of arrest- 
ing, 133. 


Vanilla, on its production in Europe, 
116. 

Vegetable monstrosities, on, 120. 

Veins, action of substances injected 
into the, 129. 

Velasquez de Leon (Lt.-Col.) on the 
government-map of Mexico, 98. 
Viaducts of timber, on constructing, 

150. 
Visible direction, on the law of, 7. 
Vision, on an ocular parallax in, 7. 


‘| Volcanos, lunar, 93. 


Voltaic combination, its influence on 
chemical action, 69. 


Wallace (Clay) on some preparationsof 
the eye by, 14. 

Wallace (Mr:) on an inosculation in 
two trees, 120. 
Washington (Capt.), account of a Man- 
dingo, native of Nyani-Mar4, 97. 
—— on expeditions to the Antarctic 
seas, 97. 

, account of the various Govern- 
ment surveys in Europe, 98. 

Water, methods of filtering, 163. 

: Machine for raising it by an 

hydraulic belt, 158. 

of the Dead Sea, chemical exa- 
mination-of, 73. 

Water-works of Newcastle-on-Tyne, 
on the, 164. 

Watson (Rev. J.) on the Helm wind 
of Crossfell, 33. 

Webb (TI. W.) on lunar volcanos, 93. 

West (W.) on some new salts of 
mercury, 72. 

Wharton (W. L.), statistical tables of 
the engines, ventilation, pitmen, &c., 
of nine collieries in Durham, 169. 


188 


Wheatstone (Prof.) on binocular vision, 
and on the stereoscope, 16. 

White bait (Clupea alba) in the Frith 
of Forth, 109. 

Whitehaven, on the petroleum of, 60. 

Willis (Prof.) on the odontograph, 154. 

Wilson (D. H.) on the church- and 
chapel-room in All Saint’s parish, 
Newcastle, 166. 

Wilson (T.), account of the Darton 
Collieries’ Club, 173. 

Witham (H. T. M.) on rolled stones 
found in the coal seam of Cockfield 
Fell Colliery, 79. 

Wollaston’s goniometer, on an alter- 
ation in, 153. 


INDEX II. 


Wombat, on the, 111. 

Wood (N.) on the red sandstone of 
the Tweed and Carlisle, 78. 

Writing-tables, improved, 156. 


Yarrell (W.) on a new species of 
smelt, 108. 

Yelloly (Dr.) on an improved acoustic 
instrument, 129. 

Young (Rev. Dr.) on the antiquity of 
organic remains, 95. Ry: 


Zinc, carbonate of, on the production 
of a horizontal vein of, 90. 
Zoology, 100. 


THE END. 


Printed by Richard and John E. Taylor, Red Lien Court Fleet Strect. 


Lighth report of the Brit.Assoc. tor the advancement of Science 1838, 


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CATALOGUE 


OF THE 


MODELS OF INVENTIONS, 


PRODUCTS OF NATIONAL INDUSTRY, 


&e. &e. 


CONTAINED IN 


THE FIRST EXHIBITION 


OF THE 


NEWCASTLE-UPON-TYNE, 
AUGUST, 1838. 


PRINTED BY JOHN HERNAMAN, 19; GREY-STI 


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4 


AT a MEETING of the General Committee of the 
BritisH ASSOCIATION, held at Liverpool, on the 
16th of September, 1837. 


THE EARL OF BURLINGTON IN THE CHAIR; 


It was moved by Sir D. Brewster, seconded by R. I. Murcuison, 
and carried unanimously,—‘“ That a Committee be appointed to super- 
intend the Exhibition of Mechanical Inventions at Newcastle, viz., 
Sir D. Brewster, Mr. Babbage, Professor Wheatstone, Professor 
Willis, Professor Powell,—Professor Johnston to be the Secretary, with 
power to add to their number.” 

In accordance with this resolution the Secretary, after consulting 
with Sir D. Brewster, Mr. Babbage, and Professor Wheatstone, drew 
up the following circular, and transmitted it to the various manufac- 
turing districts in Great Britain and Ireland : 


BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 
NEWCASTLE MEETING, 1838. 


EXHIBITION OF MODELS, PHILOSOPHICAL INSTRUMENTS, AND PRODUCTS 
OF NATIONAL INDUSTRY. 


It is a subject of regret to many that the facilities afforded by the 
Meetings of the British Association for the Exhibitions of Models, &c. 
have not hitherto been generally known or properly appreciated. The 
general Committee of the Association appointed for this purpose, in 
conjunction with the Local Committee in Newcastle, beg leave, there- 
fore, to call your attention to the opportunity afforded by the meeting 
together of the most eminent men of science, from all parts of the 
kingdom, for making known the merits of inventions, the excellence of 
instruments, and the value of the products of industry in general, and 
to invite you to avail yourself of this opportunity. 

Philosophical instruments—models of inventions, of improvements in 
machinery, of new applications of the mechanical powers, of workings 
in mines, &c.—products of national industry, new, rare, remarkable in 
any respect, or exhibiting the progress of any department of the arts, or 


4 


of the application of scientific principles to their improvement—illus- 
trations of the rise of new arts from new discoveries in science—re- 
markable natura! and artificial productions, especially such as are likely 
to be of use in the arts—interesting geological sections, &e., are among 
the objects it is desirable to exhibit. An accurate description, pointing 


out especially what is considered new or remarkable in it, should ac- _ 


company each specimen. Convenient rooms are provided for their re- 
ception, and, if the owners are not themselves present at the meeting, 
the articles will be returned as may be directed. 

Packages must be addressed (carriage paid) to the local Secretaries, 
or to the assistant general Secretary of the British Association, at the 
Rooms of the Literary and Philosophical Society, Newcastle, and 
should arrive on or before Friday the 10th August, of the present year. 


JAMES F. W. JOHNSTON, Secretary. 
Newcastle, July 1, 1838- 


i 
PLAN OF THE EXHIBITION. 


THE EXHIBITION WILL CONSIST OF TWO PARTS. 


I.—Specimens connected with the Arts and the Developement of 
National Industry. 

A, Locau.—Articles manufactured in the district, showing the nature 
of the products of local industry—the present state of the manu- 
factures—Specimens illustrating the improvement or progress 
of the several branches. 

B. Gunerav.—Products of industry from all parts of the kingdom— 
Specimens illustrating the different steps from the raw material 
to the finished article. 

Raw materials of a less common kind, which are or may be applied 
to useful purposes in the arts—which are used or abundantly pro- 
duced, or may be so, either at home or abroad, and are susceptible 
of beneficial application to industrial purposes. 


11.— Mechanical and Philosophical. 
A.—Models of Machines, or parts of Machines—old, new, or im- 
proved ; or illustrating the gradual progress of invention. 
Models of workings in mines. 


OO 


5 


B.—Philosophical instruments—new, nicely adjusted, or for the pur- 
pose of comparison. 

C.—Remarkable Minerals—interesting Geological Sections—Fossils— 
rare or curious Specimens in any of the branches of Natural 
History. 

N.B. The Exhibition will be open to all Members of the Associa- 
ation and their families, and to all other persons who may have trans- 
mitted any article considered worthy of a place in the collection. 


ST 


Mr. Grainger, to whose liberality the Association is in other re- 
spects so much indebted, having placed an elegant and spacious room 
at the disposal of the local Committee for the purposes of the Exhibi- 
tion ; the objects of interest contained in the following catalogue were 
arranged in it, and access given to the members of the Association on 
Tuesday the 21st of August. 

In future, it would be very desirable to insist on the models, &c. 
being sent in at least one week before the day of meeting of the As- 
sociation, that the Exhibition may be opened before the arrival of the 
strangers. The aid of wood cuts or other illustrations should also be 
employed in order that the list of articles contained in the Exhibition 
may be made as much of a catalogue raisonnée as possible. The delays 
and inconveniences attending the reception and arrangement of the 
specimens in the present Exhibition have prevented the catalogue from 
appearing so soon, or in so complete a form, as on future occasions may 
reasonably be expected. 


JAMES F. W. JOHNSTON, Secretary. 
Newcastle, 24th August, 1838. 


CATALOGUE 


or 


PHILOSOPHICAL INSTRUMENTS, &c. 


MECHANICAL INVENTIONS. 


1. The Pendulous Printing Press—By Thomas Edmonson, 
Milton Station.—This instrument has been invented for the pur- 
pose of dating the tickets given to passengers on the Newcastle 
and Carlisle Railway with facility and despatch. Upwards of 
ten thousand tickets can be printed by it with one supply of ink. 
This is accomplished by means of a ribbon saturated with a pecu- 
liar inking composition, attached to two small rollers, and shift- 
ed by the pressure of the finger against the instrument. The 
impression, which is dry and permanent, is obtained by simply 
putting the ticket into a space left for it in the centre of the press. 

2. Model of a Chair and Rail, with Guard, to prevent Car- 
riages running off Railways, with drawings of a steam boiler, &c. 
By Ralph Rewcastle. 


3. Intermitting Spring. 
—By W. L. Wharton, 
Esq., of Dryburn.—A 
model to prove that the 
flowing water, in all in- 
termitting springs, first 
forms a valve for the ex- 
clusion of the atmos- 
phere, and then a pump 


for forcing out the air 
from the syphon. An intermitting fountain is formed by closing 
the tube T of the cup, (which when filled with water forms the 
valve at the foot of the syphon.) Upon opening T, the water 
flows without intermission. 


4. Stand and Staff 
for a Level—By W. L. 
Wharton, Esq., Dryburn. 
A stand and staff for a 
level, intended to expedite 
the common operations of 
levelling. The axis of the 
= == S : telescope, and the Zeroofan 
SS ascending and also a de- 
scending scale upon the staff, are fixed at one height (5 feet) above 
the ground, and the difference of level of the respective sites of 
the staff and stand is at once ascertained from one or the other 
scale, upon directing the telescope (when adjusted) to the staff. 

5. Safety Coal Gin.—J. G. Wright, Wakefield. 

6. Specimens illustrating the Process of manufacturing 
Needles” by Patent Machinery.—Invented by Mr. Samuel 
Cocker, Porter Works, Sheffield. 

No. 1.—Soft steel wire in lengths for 2 needles. 
2.—Do. pointed on conical files, making 10,000 revolutions per 


~ minute. 
3.—Do. grooved with an indentation for the eye. 
4.—Do. do. and eyed. 
5.—Do. filed, headed, and eyed, by punching. 
6.—Do. filed, headed, drilled, and countersunk. 
7-—Needles made according to the old mode. 
8.—Finished needles (sharps) made by patent machinery. 
9.—Do. . (betweens) do. 

The value of labour from the wire No. 1 to No. 7 (inclusive) would , 
be Is. ld. per thousand. The expence by patent machinery from No. 
1 to No. 5 or 6, inclusive, 1d. per thousand. 

100 patent machines, which would occupy four rooms, each about 
25 yards by 10, will, by the power of a six horse steam engine, be suf- 
ficient to produce 14,000,000 needles per week. 

The fash, made in grooving, is filed off by circular cutters, in the last 
operation of the machine, leaving the needle in the state of No. 5 or 6. 

7. A Specimen of Flooring Deals with Hoop Iron Sliffers.— 
Wm. Holmes, Neweastle.—The advantages of which are—firm- 


9 


ness in the floor, more security against depredation, the iron 
presenting an additional obstruction to the floor being sawn 
through, and the preservation of the strength of the deals in a 
greater degree than by the ordinary wood sliffers. 

8. Sling Fracture Bed—By T. M. Greenhow, Esq. New- 
castle. The sling fracture bed consists of two parts. 1. The 
first part is of the nature of a splint to which the injured limb 
is fixed ; and the several portions of which admit of extension 
by means of screws to accommodate them to the case under 
treatment. 2. The second part is a support by means of which 
the former part of the instrument is slung in an easy position. 
The mode of application will be easily understood on inspection 
of the instrument. The advantages of this plan of treatment 
are—ease and security to the patient, the power of moving toa 
certain degree without hazard of displacement, and facility of 
dressing wounds in cases of compound fractures. 

9. Splint for Fractures of the Lower Extremities—By J. 
Baird, Newcastle. 

10. A Cultivator—By Anthony Hall, Prudhoe.—Model 
one-fourth the working size. With this instrument a man can 
dig one-fifth of an acre per day. 

11. Improved Colliery Bow and Hook, for the prevention of 
accidents, in coal mines, occasioned by corves (in which the coals 
are brought up from the pit) falling from the hooks affixed at 
the end of the rope or chain. The improvement of the Bow con- 
sists in the under surface of it being lozenge shaped, so that not . 
having a flat surface, as is usually the case, the bow cannot rest 
on the point of the hook, and must either slip into the bend of 
the hook at once, or fall off altogether, in either of which cases 
no accident can happen. 

12. Union Joint for Fire Engine Pipes.—By John Gardner, 
Gun-maker, Newcastle-upon-Tyne—When the joint is put to- 
gether the bolt is pressed with the thumb, and the self-acting 
spring prevents the bolt from shifting by any action whatever, 
and when the joint is to be taken asunder the bolt head is pressed 
with the finger and thumb and drawn at the same time, and then 


10 


giving the joint a quarter turn it will come asunder. The put- 
ting together and taking asunder will not take more than a very 
few seconds. It is perfectly tight to air and steam. 

13. Model of a new method of Working the Valves of a Loco- 
motive Engine, by R.and W. Hawthorn, Newcastle-upon-Tyne. 


BOILER. 


leas 
ig 


I 
i] 
m1 i 
émml ae 


ay SS 
Lain, nA SOAS 
Lm a TDAH 
UI TMA NOOO WS RSS 
FATS 


A.—Centre of Slide Rod. B.—Centre of Cylinder. 


The slider ais attached by a pin to the centre of the con- 
necting rod, working in the frame b 6, which gives to the frame 
a reciprocating motion vertically from the connecting rod at 
every revolution of the cranked axle. The upper arm of the 
frame 6 b is conected with the arm d, fixed on the same weigh- 
bar as the double arm ¢, by which the motion is communicated 
to the slide valve by the change rod e. g is the reversing weigh- 
bar, having three arms, // nm fixed upon it. The arm h is moved 
by the rod #, communicating with the reversing handle or lever 
worked by the engineman. / is connected to the change rod e, 
by the bar m, which by moving the reversing handle or lever 
can be changed from one of those pins to the other at the ends 
of the double arm c, and the engine made to go in either di- 
rection required. 

The arm » has a box witha set screw for adjusting its 
length, by which any angle in a few minutes can be given to the 
frame 6 b, which is a very important part in this arrange- 


‘XOd GUA 


11 


ment; as the readiness and simplicity with which the lead can 
be given to the slide valves, to correspond with the various speeds 
and loads the engine may be put to, is a desideratum which 
could not be obtained by eccentrics, without much labour and 
time in loosening and resetting the eccentric wheels. 


14. Dr. Lardner’s Self-Re- 
cording Steam Journal, con- 
structed for the Steam Navi- 
gation Committeeof the British 
Association.—The purpose of 
this apparatus is to register by 
mechanism those several vary- 
ing effects connected with the 
operation of the engines and 
the performance of steam ves- 
sels, on which their efficiency 
depends. It will be attempted 
by means of the present mecha- 
nism to make and preserve 


a constant record from five 
minutes to five minutes, of 


1.—The pressure of steam be- 
tween the slides and the steam 
valve. 


2.—The pressure of steam in 
the boiler. 
3—The state of the vacuum 


in the condensor. 
4.—The part of the stroke at which the steam is cut off when it works 
expansively. 


5.—The quantity of water in the boilers. 
6.—The saltness of the water in the boilers. 
7.—The velocity of the paddle wheels. 
8.—The draft of the vessel. 
9.—The trim of the vessel. 
10.—The rate of the vessel. 
11.—The course of the vessel. 


12 


12.—The apparent force of the wind. 
13.—The apparent direction of the wind. 

The above will be registered by self-acting niechanism, ex- 
cept the eleventh, (the course of the vessel,) the indicator of 
which will require occasional manipulation. 


15. Dr. Lardner’s Self-Registering Steam Guage, or Experi- . 


ments with Locomotive Engines, constructed for the Committee 
of the British Association on Railway Constants.——The purpose 
of this apparatus is to register by self-acting mechanism the 
pressure of steam in the boiler at each point of the road over 
which the engine passes. 

16. Improved Writing Table, by T. Sopwith, F.G.S.—This 
table is so contrived that the whole of the drawers, closets, and 
partitions are fastened by means of a single lock, placed on the 
flap which forms the writing desk. 

17. A beautiful Miniature Working Model of a High Pres- 
sure Steam Engine and Planeing Machine.—By James Frazer, 
Brass-finisher, Newcastle. 

18. Working Model of a Steam Engine with vibrating Pillar, 
made by John Brown and Son, Grey-street, Newcastle. 

19. Model of a Patent Air Engine.—By Crossley & Parkinson. 

20. Model of Hay and Corn Rake—Hutchinson and Swales, 
Agricultural Instrument Makers, Newcastle. 

21. Model of anew Telegraph.—By Dr. Clanny, Sunderland. 
By this Telagraph, either spelling as in short hand or a vocabu- 
lary as in the common Telegraph may be employed; and by 
attaching to it a powerful lamp, it may be rendered as service- 
able by night as by day. The introduction of spelling will 


permit communications to be interchanged in regard to all sub- 


jects, which in respect to meteorology and other scientific sub- 


jects appears very important. 

22. Improved Two-armed Telegraph.—By Joseph Garnett, 
Newcastle.—This model exhibits the construction of the telegraph, 
and the mode of working the arms by a more easy and rapid 
method than the telegraph in common use. 

23. Drawings of the Signals made by means of J. Garnett’s 


ou 


13 


Telegraph._—No. 1, shows the position of the two arms for day ~ 
signals. No. 2, shows the position of the lamps for night signals. 
No. 3, shows the arrangement for effecting the night signals. 

24. Model of a Self Acting Fire Alarm.—Constructed on the 
principle of the expansion of metals by heat, acting on compound 
levers and disengaging a spring, which sets off a bell. 

25. Model of a Self-acting Ventilator—Founded on the same 
principles as the above Fire Alarm, but in this a door or 
aperture is opened or shut by the application of heat. 

26. Model of an Improved Mode of Ship-building, and of a 
new Safety Keel.—By Oliver Laing, Esq. Woolwich. 

27. Model of a Machine for pumping Vessels and extinguish- 
ing Fires on Shipboard.—By J. Dalziel, M.D.—The moving 
power of this machine is derived from the acticn of the water 
on paddle wheels, when the vessel is under way. 

28. Model of Railway formed on continuous Blocks of Stone. 

29. Model of Steam Boiler Copper. 

30. Ditto, Ditto. 

31. Ditto, Ditto. Wood. ‘ 

By Joseph Price, Esq. Gateshead. 

32. Model of a Patent Wind/ass.—By George Straker. 

33. Model of a Force Pump.—By John Lightfoot. 

34. Improved Articulated Stethescope—By Dr. Granville. 

35. Model of an Apparatus for promoting Artificial Respira- 

tion.—By J. Dalziel, M.D. 
; 36. Gas Meter.—By Crossley, with transparent cut back and 
front, shewing its action. 

37. Working Model of another Gas Meter.—By Crossley, 
with three transparent chambers attached to a gas holder. 

38. Telescope exhibiting a new method of Mounting.—By C. 
Garbutt, Gateshead. 

39. Mode of applying the Common Level to the purposes of the 
Transit Instrument.—By the Rev. N. 8. Heineken, Sidmouth. 
The object of this model is to show the application of the com- — 
mon Y level, slightly altered, to the purposes of the transit in- 
strument, so that any clockmaker may construct for himself an 


14 


instrument by which he may ascertain the time for rating his 
clocks with far greater accuracy than by the ordinary means of 
the sun-dial and meridian line—the instrument’ may be con- 
structed at a very trifling cost and made to serve the purposes of 
a level also. 


40. Eye Piece with Cavallo’s Pearl Micrometer.—By the Rev. - 


N.S. Heineken. ‘This is intended to obviate the objections to 
the application of this simple micrometer to the reflecting 
telescope. 

41. New Self-registering Thermometer.—By 
John Brown and Son, Opticians, &c. Grey-street, 


Newcastle-—The construction of this instrument 
¥ will be understood by the annexed diagram; A is 
a glass tube filled with pure spirit of wine; Bisa 
continuation of the same but much smaller, which 
is to be about half full of quicksilver to support 
the spirit in the long tube; upon the quicksilver at 
G is a float supporting the wire C, which wire has a 
knee or bend in it with a small eve, which runs upon 
the fixed wire D, carrying an index or pointer ; Eis 
the scale which must be made experimentally. The 
action of the instrument is obvious. If any change 
takes place in the bulk of the spirit the quicksilver 
is also affected, and with the silver the ivory float G carrying 
the index or pointer, which shews at once the degree of tempera- 
ture upon the scale; this is the simple action of the thermo- 
meter. To make it register, the two light indexes or pointers F 
move upon the wire D, their own friction keeping them where- 
ever they are placed. To set it the pointer F below the thermo- 
meter’s index must be pushed close up to it, and the pointer F 
above, pushed down it; and it is evident that if any change of 
temperature takes place the thermometer’s index will move the 
registering index either above or below, and leave it there, 
thereby shewing the extreme rise and fall of the thermometer in 
any given time. The action of the air upon the quicksilver is 
also provided against. 


15 


42. An improved Marine and Mountain Barometer.—By 
Sir David Milne. 

The construction of this instrument allows it to be used as a Marine 
Barometer. Inthe middle of the tube, or half way down, the bore is 
reduced to the size of an ordinary thermometer bore, in consequence of 
which the mercury is prevented from flowing rapidly and violently into 
the upper part of the tube, when the instrument swings about. The 
open end of the tube through which the atmosphere acts on the mer- 
cury, is so constructed, that the mercury does not run out or escape 
when the instrument is upset. 

43. Patent Safety Spring for Carriages —By Barton.—This 
spring unites greater strength and safety with a much less weight 
of material than is contained in the ordinary carriage spring. 

44. Portable Mercurial Pendulum.—By K.J. Dent, London. 

45. Pneumatic Apparatus.—— By Dr. Clanny.—For extract- 
ing and analysing the air contained in blood, and other fluids, at 
low temperatures by which the possibility of chemical changes 
by the action of heat is prevented.— See Lancet, 23rd Aug. 1834. 

46. Apparatus for receiving blood from the hand in tepid 
water.—By Dr. Clanny. 

47. Apparatus for receiving blood in vacuo.—By Dr. Clanny. 

48. Instruments for crushing Stone in the Bladder—John 
Brown and Son, Grey-street, Newcastle. 

49. A new Chuck for turning Wire into Screws, &c. or for 
holding Drills—By Charles T. Couthope, Bristol. 

50. Hall’s Patent Hydraulic Belt for raising Water. 

A woollen belt is passed over a roller at the top of the shaft and under 
one at the bottom, and by giving the belt a velocity of about 1000 feet 
per minute, the water adheres to the belt, and is brought up and dis- 
charged into a trough by the centrifugal force in passing over the top 
roller. It possesses most important advantages over the pump, and is 
particularly applicable to coal pits, mines, &c. &c. 

1st.—Producing more water with the same power. 
2d.—The economy in cost and repairs. 
3d.—The saving of time during the repairs, &c. 

51. Model of the present House of Commons, illustrating 

the ventilating arrangements introduced by Dr. D. B. Reid. 


16 


The air that supplies the House being properly prepared and purified 
enters either by the ceiling or by the floor, according to the arrangement 
of the valves. The sketch No. 1, illustrates the progress of the air 
from the ceiling to the floor, and No. 2, shows the progress of the air 
when the current is reversed, proceeding from the floor to the ceiling. 

52. Else’s Patent Cylinder for Malt Drying; and Portable 
Kiln for Drying Corn and Seed, by which machine uniformity 
of dryifiz, and the production of any shade of colour in the 
mali con with certainty be effected; and manual labour on the 
kiln is wholly dispensed with. The malt can also be screened 
while drying, and the whole of the malt-dust preserved uninjured. 

53. Drawings of a Planeing Machine—a Self-acting Drit- 
ling Machine—and a Slide Lathe.—By Joseph Whitworth and 
Co. Engineers, Manchester. 


54. Model of Lindley’s Patent Bellows, working in an up- 
right frame, by means of a rack staff, avle, rod, &c. 

It consists of four boards, the second and fourth are fixed and kept a 
certain distance from each other (according to the length of the stroke 
required) by means of pieces of iron, the upper board rises and falls, the 


Ry’ 


third plays between the second and fourth (or bottom board). Between 
the boards are frames of wood to support the leather. Three of the boards 
are so furnished with valves and other apparatus that the machine, when 
covered with leather and fitted up, works like a double acting steam 
cylinder, the space between the two upper boards forming the common 
chamber, whence the air is conveyed through the pipe to the fire. 
Upon the third board going down the air will rush in and fill the space 
between the second and third boards; upon the same board , 7 up 
the air will rush in and fill the space between the third and’ fourth 
boards ; when the rack staff is pulled down the air is forced from be- 
tween the second and third boards into the chamber between the first 
and second boards; when the staff returns the air is driven from be- 
tween the third and fourth boards into the same chamber ; thus, when 
the staff rises or falls the air is forced into the common chamber, by 
which means a middle pipe is supported, and a constant and steady, as 
well as powerful blast is obtained, capable of fusing a bar of iron when 
one end of it is made red hot. 

55. An Odontograph.—By Professor Willis, of Cambridge. 
This instrument is intended for setting out the forms of teeth, 
so that any two wheels of a set may work truly together.—Vide 
Trans. of Civil Engineers. Vol. II. p. 2. 

56. Specimens of Scales of equal parts—By Charles H. 
Holzapffel—These scales are applicable to various purposes of 
engineering, architecture, and general science. 

57. Bates Anaglyptograph for representing relieved sur- 
faces.—By the use of this machine lights and shadows are truly 
represented. 

58. Model of a Life Preserver.—By J. Clark, of York —_ 
To be put on as a short jacket, buttoned and buckled in front ; 
made of jean prepared with caoutchouc and perfectly air tight ; 
on this is another covering of jean, and the whole is inclosed in 
caoutchouc. 


18 


PRODUCTS OF INDUSTRY, ARTS, AND 
MANUFACTURES. 


59. Specimens of Printing in Oil Colours.—By G. Baxter, 
London. 


60. Siw Inch Speculum for Reflecting Telescope.—Cut and 


ground by Joseph Redshaw, tailor, Gateshead. 

61. A Plate of Fine Silver.—Benjamin Johnson, Esq. 

62. Specimens of Colours produced by thin films of Oxide on 
the surface of Metallic Lead.—Benjamin Johnson, Esq. 

63. Plate of Fine Silver.—Locke, Blackett and Co. 

64. Fire Bricks —By T. Carr, Scotswood.—Showing the pre- 
sent state of the manufacture. Also a specimen of raw clay 
as brought out of the mine, same as the bricks are pestle 
tured from. 

65. Printed and Dyed Leather—¥From Jon. Priestman, 
' Low Friar-street, Newcastle. 

66. Specimens of Paper Staining.—From Daniels and Co., 
Newgate-street, Newcastle-upon-Tyne. 

67. Model of a Coal Waggon in Silver.—Messrs. Reid & Son. 

68. Specimen of Silk Waste (Strusa.)—James Holdforth, 
Esq., Leeds. 

About thirty years ago this article was considered of no value 
except for tillage for which it was used by the Italians. Various 
experiments and attempts were at intervals made to apply machi- 
nery to its manufacture, which of late have been so far perfected 
that it can now be wrought into a beautifully fine thread as the 
accompanying sample will shew, and has become an article of 
considerable importance and value. 

69. Specimen of Silk Yarn.—James Holdforth, Esq., Leeds. 

In one ed weight of this there are 150,000 yards, which 
is equal to 854 miles in length. 

70. Sosbtnheies of Flaxes and Yarns, from Messrs. ine and 
Atkinson, Leeds. 

A. the coarsest line yarns we produce. B.a medium quality 
and size. C. The finest ever produced, and we believe to be 


19 


finer than has been ever produced elsewhere, from flax. The 
three sorts of flaxes are what we are generally using, worth from 
A. £40 per ton, B. about £60, and C. £60 to £70. Our finest 
flaxes similar to those the fine hank is produced from, are worth 
£200 per ton. 

71. Specimens of Poplins or Tabinets figured and brocaded. 
By Messrs. Atkinson & Co., Dublin. 

Ist. A splendid Pink and Silver Tissue Poplin same as worn by 
Majesty at her first Drawing-Room. 

2nd. White, Gold, and Green, worked on an improved principle, 
which obtained the highest class premium from the Royal Dublin 
Society, in June, 1838. . 

3rd. Several patterns of Gold and Silver Tissues for Gentlemen’s 
waistcoats. , : 

4th. Furniture Tabouret, which obtained a silver medal from the 
Royal Dublin Society. 

72. Map of the World, by James Wild.—This map is designed 
to show the languages and dialects into which the British and 
Foreign Bible Society have translated the Scriptures. 

73. Geographical Clock, exhibiting Diurnal motion of the 
Earth, &c.—By Geo. R. Taylor, Sunderland. 

74. A Painting on Glass—By Joseph Price, Esq. Gates- 
head. 

75. Specimens of Engraving on Glass—By Joseph Price, 
Esq. Gateshead. 

16. Models ofa Rifle Bullet for Small and Great Guns —By 
Oliver Byrne.—With casts of the barrels. 

77. Prints and Metal Plates, illustrating Woone’s Patent 
Metallic Relief Engravings.—This invention affords an easy and 
expeditious method of obtaining Engravings or Etchings in 
Relief, capable of being printed at the type press in the manner 
of wood engravings. The process employed for this purpose is 
to form a mould from which casts can be taken in metal by 
drawing with a steel point or etcher through a thin composition 
of Plaster of Paris and White Lead, laid on an even plate of 
metal. 


20 


78. Specimens of Patent Encaustic Tiles—By Davis and 
Co. Blackett-street, Newcastle—The improvement exhibited by 
these beautiful tiles consists in their being ground perfectly flat 
before the dssign and glaze are applied. They can be made of 
any size, and are applicable to a great variety of useful purposes. | 

79. Model of a Railroad for facilitating the draught of heavy 
weights up inclined planes in common carts or waggons, and 
drawn by one horse.—By Sir Charles Monteith, Bart. 

80. The Coronation Medal.—By Pistrucci. 

81. Medal to commemorate her Majesty's visit to the City of 
London.—By W. Wyon. 

82. Specimen of the New Coinage-—By W. Wyon. 

83. Stockings knit by Patent Machinery—By Whitworth 
and Co., Manchester. 

* 84. Plate Glass Prism and Polygon, richly cut.—By Robert 
Walter Swinburn, Esq. 

85. Specimens of Raper’s Patent Waterproof Cloth—Depo- 
sited by Mr. William Maugham. 

86. Patent Wire Rope for Standing Rigging—By Mr. 
Andrew Smith, London. 

87. Specimens of a Web of Copper Wire——That numbered 
90, contains 8,100 appertures to the square inch ; and number 
100, 10,000 ditto, ditto—From Wm. Mountain and Sons. 

88. The Brandling Knife-—By John Brown and Son, Grey- 
street, Newcastle. 

89. Flax, Line, and Tow.—Marshall and Co. Leeds.— 
August 8, 1838. 

Price at Leeds per Ton. 


Common ( Antwerp ,% ...£63 ) Producing Line for 20 Leas and 5lbs. 
Flemish Yarn—Tow for 18 Leas and 30 
Flax. Courtrai yy ...£67 Yarn. 


Fine Antwerp | ...£140) Producing Line for 120 Leas and 240 
Flemish Yarn—Tow for 60 Leas and 


Flax. {Courtrai jj ...£160 140 Yarn. 


: 
: 
: 


21 


ARCHITECTURE, BRIDGES, &c. 


90. Timber Bridge—200 feet span, which is the largest span 
in timber that has been attempted in this country.—Kach curved 
under bearer forms an abutment for each pair of struts which 
support the upper bearers, both the upper and under bearers 
are so connected together by the struts and suspending pieces, 


that the framing forms a solid rib, upon which the joists for 


supporting the roadway are sustained, and the whole weight 
of the bridge itself and the weights passing along it, ultimately 
rest upon the abutments. This bridge is intended for turnpike- 
road traffic, but the principle may be applied to any other kind 
of traffic, such as railway traffic, with heavy locomotive engines 
passing at rapid rates. A bridge of two arches, each similar to 
the above, is now about to be erected over the Tweed at 
Norham.—J. Blackmore, Esq. engineer, Newcastle. 

91. Model of Piers for a Suspension Bridge. By J. Green, 
Architect and Engineer.—Proposed to be erected across the 
mouth of the Tyne, in 1827, at the height of 110 feet above 
high water level, and 1,000 feet span. 

92. Model of a Suspension Bridge, in which the suspending 
rods are inclined instead of being vertical as in the usual con- 
struction.—By James Dredge, Esq. Bath. 

93. Model of a Monument—erected in the Westgate Cemetry, 
Newcastle, by Benjamin Green, Architect. 

94. Model of an Arch—120 feet span, by John and Benjamin ~ 
Green, architects, being part of a bridge of five arches, designed. 
in 1834, which obtained the premium offered by the Newcastle and 
Carlisle Railway Company at that time, for crossing the River 
Tyne above Scotswood. This arch is on the same principle as 
the immense viaducts now in progress on the Newcastle and 
North Shields Railway. 

95. Model of a Timber Arch, on a new construction. By 
Messrs. Green, Architects.—In this arch the ribs are put together 
with Dantzic deals, in lengths of from 21 feet to 45 feet, 11 
inches broad, and 34 inches thick, fixed together with oak tree- 
nails. The experiments tried have sufficiently proved the strength 


22 


of such arches, and the durability they possess over other 
wooden bridges arises from the simplicity of their construction. 


SSS SS SS SS 
i 


The model is on a scale of half an inch to the foot. 

A viaduct of 5 arches on this principle is in progress of con- 
struction over Ouseburn, and another at Willington Dean, of 
7 arches, the span of these arches being from 116 to 118 feet, 
and the height of the bridges from 82 to 108 feet. The plans 
and sections are to be seen in the model room. 

96. Model of the Grey Column.—By John & Benjamin Green, 
architects, now erecting at the north end of Grey-street, New- 
castle-—The total height to the top of the figure will be 133 
feet, the diameter of the shaft is 9 feet 11 inches. The order 
is of the Roman Doric, and there is a staircase consisting of 164 
steps to the top of the abacus of the capital, from which there is 
a fine panoramic view of the town and the surrounding country. 

97. Model of a Gothic Cross—designed by Benjamin Green. 

98. Model of a Church—designed by J. Green, Architect. 

99. Model of St. Nicholas’ Steeple, in Newcastle.-—Made by 
Charles M‘Kenzie, Brazier, Newcastle-—Deposited by T. Sop- 
with, Esq. 

100. Model of the New Corn Exchange and other Buildings 
attached thereto, now in progress opposite St. Nicholas’ Church, 
Newcastle.—John and Benjamin Green, architects. 

101. Isometrical Drawing of a proposed New Street in 
Newcastle.—By T. Sopwith, F.G.S. 

102. Drawing of one of Mr. Owen's Communities for the 
Superior or Educated Classes—Deposited by Mr. Owen. 


23 


CHEMICAL PRODUCTS. 


103. Specimens of Prussian Blue and of large Crystals of 
Prussiate of Potash—Thomas Bramwell, Esq., Newcastle.— 


The quantity of these substances manufactured by the sole ~ 


maker on the Tyne is about 110 tons a year. The average price 
is one shilling and a penny per pound—total value, £24,640. 
In 1828 the average price was 5s. per pound. 

104. Specimens illustrating the action of the preserving 
substance employed in Kyan’s patent process.—Deposited by 
Richard Fell—These specimens of fir pit props and calico bags, 
containing pieces of No. 2 canvas, cordage and twine, prepared 
according to the patent process, together with unprepared 
articles of the same description, which had been respectively 
exposed for a lengthened period of time to the same destructive 
agents. 

105. Specimens of Leather, and Model of a Machine, illus- 
trating a new mode of Tanning.—By William Herapath, Esq. 
Bristol.—For an account of this important improvement in the 
art of tanning see the Mechanics’ Magazine for April, 1828. 

Action of Water on Herapath’s Patent Leather. 


@ On thick sole after five hours. 


Do...... after nine hours. 


= eet OX thin sole after nine hours. 


106. Large Crystals of Alum and Soda.—From John Lee 
and Co.—The quantity of Soda annually manufactured on the 
Tyne amounts at present to about 20,000 tons of crystalized at 
£11, and 10,000 of dry at £15 per ton—total value £370,000. 
The price of the two varieties in 1828 was £20 and £25 respec- 
tively. Of Alum about 2,000 tons are manufactured by the 
direct action of Sulphuric Acid on clay. The present price is 
£10 per ton. 


s 


24 


107. Of Soda and Sulphate of Copper—By Messrs. Cook- _. 
son.—About 150 tons of Sulphate of Copper are manufactured 
annually on the Tyne. The price is £35 per ton—total value 
£5,250. : 

108. Specimens of Flint Glass Manufacture. 

109. Ditto Imperial Sheet Glass ( Flint.) 

110. Ditto Pilate Glass. 

111. Ditto Crown Glass. 

112. Ditto Double Crown.—By Joseph Price, Esq. Gates- 
head. 

113. Crystals of Bicarbonate of Soda.—Messrs. Cookson. 

114. Large groups of Crystals of Nitrate of Soda.—Messrs. 
Cookson. 

115. Specimens of artificial Pyrites—George Lowe, Esq. 
London. 

116. Large group of Crystals of Sulphate of Iron.—William 
Caley, Esq.—About 2,000 tons of this salt are annually manu- 
factured on the Tyne. 

117. Eleven Specimens of Bohemian Glass.—Deposited by 
the Rev. John Collinson, Gateshead. 

118. Specimens of Glass and Porcelain.—Deposited by 
Joseph Townsend, Newcastle. 


25 
GEOLOGICAL, &c. 


119. Profile of the Coast and Longitudinal Section of the Coal 
Strata near Whitehaven.—By Williamson Peile, Esq. F.G.S.— 
Exhibiting (on a natural scale) the succession of mountain lime- 
stone, coal strata, lower red sandstone, magnesian limestone, 
and new red sandstone rocks. 

Transverse sections of Whitehaven Colliery on the small 
natural scale of four inches per mile, and— 

Four sections of Whitehaven Colliery, exhibiting the numer- 
ous slip dykes, natural scale 50 yards per mile——Williamson 
‘Peile, Esq., of Whitehaven. 

120. Model of the Town of Whitehaven, and the,Coal Mines 
beneath.—Deposited by W. Peile, Esq. 

121. Model of Dean Forest, in the county of Gloucester.— 
Made for the Honourable Commissioners of Woods and Forests, 
by T. Sopwith, F.G.S. This model is constructed so as to show 
the relative elevation of the principal seams of coal. 

122. Sections of the Strata in Dean Forest.—By T. Sop- 
with, Esq. 

123. Plans and Sections to illustrate the Strata and Mining 
operations in Alston Moor.—By T. Sopwith, F.G.S.—The sec- 
tions exhibit the succession of strata and the whole of the work- 
ings in the lead mines. 

124. Model, illustrating the method of ventilating Coal Mines. 
By John Buddle, Esq. 

125. Miners’ Air-measuring Machine.—By Thomas Elliott, 
Pensher Colliery.—For the purpose of measuring the velocity of 
air in mines at any instant of time, and also for registering its 
mean velocity for any given time. No machine previously in- 
vented for measuring air in mines has been applied to the useful 
and important purpose of registering its mean rate. The coal 
trade meeting of this town presented the inventor with ten 
guineas, as a mark of their approbation of this invention. 

126. Safety Lamp, with Extinguisher —Thomas Bonner, 
Monkwearmouth. 


26 


127. An Instrument for distinguishing Precious Stones and 
Minerals.—By Sir David Brewster, K.H.. F.R3S., &c. &e. 

128. Levelling Staves for taking Surface and Subterranean 
Levels.—By Thomas Sepwith, F.G.S.—The arrangement of the 
springs in these staves admits of their being fixed at any required . 
height, with great ease. 

129. Model of the Workings and mode of Ventilation in 
Monk-Wearmouth Colliery.—By George Elliot, Viewer—This 
model shews the coal in its true position with the faults which 
traverse it on a horizontal scale of 99 feet to an inch, and 12 feet 
vertical to an inch. $ ae 

130. Model of France, in Papier Maché, presenting the in- 
equalities of the mountains.—Deposited by T. Sopwith, Esq. 

131. Model of an Apparatus for Ventilating Coal Mines.— 
By W.. Fourness, Leeds.—This apparatus acts on the principle 
of exhaustion. 

132. 1,600 Specimens of Dried Plants——Mr. Wells, Durham. 


Newcastle-upon-Tyne: Printed by John Hernaman, 19, Grey-Street. 


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