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Full text of "Report of the British Association for the Advancement of Science"

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REPORT 



NINETEENTH MEETING 




BRITISH ASSOCIATION 



ADVANCEMENT OF SCIENCE; 



HELD AT BIRMINGHAM IN SEPTEMBER 1S49. 



LONDON: 

JOHN MURRAY, ALBEMARLE STREET. 

1850. 



PRINTED BY RICHARD AND JOHN E. TAYLOR, 
RED LION COURT, FLEET STREET. 





CONTENTS. 



Page 

Objects and Rules of the Association v 

Places of Meeting and Officers from commencement viii 

Table of Council from commencement x 

Treasurer's Account xii 

Officers and Council xiv 

Officers of Sectional Committees xv 

Corresponding Members xvi 

Report of Council to the General Committee xvi 

Recommendations for Additional Reports and Researches in Science xix 

Synopsis of Money Grants , xxi 

Arrangement of the General Meetings xxvii 

Address of the President , xxix 



REPORTS OF RESEARCHES IN SCIENCE. 

A Catalogue of Observations of Luminous Meteors ; continued from 
the Reports of the British Association for 1848. By the Rev. 
Baden Powell, M.A., F.R.S. &c., Savilian Professor of Geometry, 
Oxford , 1 

Notice of Nebulae lately observed in -4h a.. Six-feet Reflector. By the 
Earl of Rosse, Pres. R.S 53 

On the Influence of Carbonic Acid Gas on the health of Plants, espe- 
cially of those allied to the Fossil Remains found in the Coal For- 
mation. By Prof. Charles G. B. Daubeny, M.D., F.R.S. &c 56 

Report on the Heat of Combination. By Thomas Andrews, M.D., 
F.R.S., M.R.LA 63 



IV CONTEXTS. 

Page 

Report of the Committee oil the Registration of the Periodic Phsenomena 
of Plants and Animals, consisting of Edwin Lankester, M.D., Mr. 
R. Taylor, ]Mr. W. Thompson, Rev. L. Jenyns, Prof. Henslow, 
Mr. A. Henfrey, Sir VV. C. Trevelyan, Bart, and Mr. Peach. ... 78 

Ninth Report of a Committee, consisting of H. E. Strickland, Prof. 
Daubeny, Prof. Henslow and Prof. Lindley, appointed to con- 
tinue their Experiments on the Growth and Vitality of Seeds 78 

Report concerning the Observatory of the British Association at Kew, 
from Aug. 9, 1848 to Sept. 12, 184'9. By Francis Ronalds, 
F.R.S., Honorary Superintendent 80 

Report on the Experimental Inquiry conducted at the request of the Bri- 
tish Association, on Railway Bar Corrosion. By Robert Mallet, 
INI.R.I.A., Mem. Inst. C.E 88 

Report on the Discussion of the Electrical Observations at Kew. By 
William Radcliff Birt 113 



OBJECTS AND RULES 

OF 

THE ASSOCIATION. 

OBJECTS. 

The 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 tiie intercourse of those 
who cultivate Science in different parts of the British Empire, with one an- 
other, and with foreign philosophers,-to obtain a more general attention to 
the objects of Science, and a removal of any disadvantages of a public kind 
which impede its progress. 

RULES. 

ADMISSION OF MEMBERS AND ASSOCIATES. 

All Persons who have attended the first Meeting shall be entitled to be- 
come Members of the Association, upon subscnbmg an obligation to con- 
form to its Rules. , r.1 1 1 • 1 c 

The Fellows and Members of Chartered Literary and Philosophical bo- 
cieties publishing Transactions, in the British Empire, shall be entitled, m 
like manner, to become Members of the Association. . ^ . - 

The Officers and Members of the Councils, or Managing Commilte^es, ot 
Philosophical Institutions, shall be entitled, in like manner, to become Mem- 
bers of the Association. i j . -^ ri -i 
All Members of a Philosophical Institution recommended by its ^.ouncU 
or Managing Committee, shall be entitled, in like manner, to become Mem- 
bers of the Association. .,..,111/-. i 
Persons not belonging to such Institutions shall be elected by the Genera 
Committee or Council, to become Life Members of the Association, Annua 
Subscribers, or Associates for the year, subject to the approval of a General 
Meeting. 

COMPOSITIONS, SUBSCRIPTIONS, AND PRIVILEGES. 

Life Members shall pay, on admission, the sum of Ten Pounds. They 
shall receive gratuitously the Reports of the Association which may be pub- 
lished after the date of such payment. They are eligible to all the offices 
of the Association. , c t^ t> a 

Annual Subscribers shall pay, on admission, the sum of Two 1 ounds, 
and in each following year the sum of One Pound. I hey shall receive 
gratuitously the Reports of the Association for the year of their admission 
and for the years in which they continue to pay without tnternussion their 
Annual Subscription. By omitting to pay this Subscription in any part.cu- 
lar year, Members of this class (Annual Subscribers) lose for that and all 
future years the privilege of receiving the volumes of the Association gratis : 
"but they may resume their Membership and other privileges at any sub- 
sequent Meeting of the Association, paying on each such occasion the sum ot 
One Pound. They are eligible to all the Offices ot the Association. 



Vi RULES OF THE ASSOCIATION. 

Associates for the year shall pay on admission the sum of One Pound. 
They shall not receive gratu'iloushj the Reports of tiie Association, nor be 
eligible to serve on Committees, or to hold any office. 

The Association consists of the following classes : — 

1. Life Members admitted from 1831 to 1845 inclusive, who have paid 
on admission Five Pounds as a composition. 

2. Life Members who in 1846, or in subsequent years, have paid on ad- 
mission Ten Pounds as a composition. 

3. Annual Members admitted from 1831 to 1839 inclusive, subject to the 
payment of One Pound annually. [May resume their Membership after in- 
termission of Annual Payment.] 

4. Annual Members admitted in any year since 18S9, subject to the pay- 
ment of Two Pounds for the first year, and One Pound in each following 
year. [May resume their Membership after intermission of Annual Pay- 
ment.] 

5. Associates for the year, subject to the payment of One Pound. 

6. Corresponding Members nominated by the Council. 

And the Members and Associates will be entitled to receive the annual 
volume of Reports, gratis, or to purchase it at reduced (or Members') price, 
according to the following specification, viz. : — 

1. Gratis. — Old Life Members who have paid Five Pounds as a compo- 

sition for Annual Payments, and previous to 1845 a further 
sum of Two Pounds as a Book Subscription, or, since 1845 a 
further sum of Five Pounds. 

New Life Members who have paid Ten Pounds as a com- 
position. 

Annual Members who have not intermitted their Annual Sub- 
scription. 

2. /// reduced or Members' Prices. — Old Life Members who have paid 

Five Pounds as a composition for Annual Payments, but no 
further sum as a Book Subscription. 

Annual Members, who have intermitted their Annual Subscrip- 
tion. 

Associates for the year. [Privilege confined to the volume for 
that year only.] 
Subscriptions shall be received by the Treasurer or Secretaries. 

MEETINGS. 

The Association sliall meet annually, for one week, or longer. The place 
of each Meeting shall be appointed by the General Committee at the pre- 
vious Meeting ; and the Arrangements for it shall be entrusted to the Offi- 
cers 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 au- 
thors of Reports in the Transactions of the Association. 

2. Members who have communicated any Paper to a Philosophical Society, 
which has been printed in its Transactions, and which relates to such subjects 
as are taken into consideration at the Sectional Meetings of the Association. 



RULES OF THE ASSOCIATION. Vll 

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

4. Office-bearers for the time being, or Delegates, not exceeding 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 desired, and who 
are specially nominated m writing for the meeting of the year by the Presi- 
dent 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. 

SECTIONAI, COMMITTEES. 

The General Committee shall appoint, at each Meeting, Committees, con- 
sisting severally of the Members most conversant 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, 

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

COMMITTEE OF RECOMMENDATIONS. 

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

All Recommendations of Grants of Money, Requests for Special Re- 
searches, and Reports on Scientific Subjects, shall be submitted to the Com- 
mittee of Recommendations, and not taken into consideration by the General 
Committee, unless previously recommended by the Committee of Recom- 
mendations. 

LOCAL COMMITTEES. 

Local Committees shall be formed by the Officers of the Association to 
assist in making arrangements for the Meetings. 

Local Committees shall liave 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 Secretaries, 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 Committee. 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. 




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MEMBERS OF COUNCIL. 



II. Table showing the Names of Members of the British Association who 
have served on the Council in former years. 

Acland, Sir Thomas D., Bart., M.P., F.R.S. 
Acland, Professor H. W., B.M., F.R.S. 



Adamson, John, Esq., F.L.S. 
Adarc, Edwin, Viscount, M.P., F.R.S. 
Airy,G. B., D.C.L., F.R.S., Astronomer Royal. 
Ainslie, Rev. Gilbert, D.D., Master of Pem- 
broke Hall, Cambridge. 
Ansted, Professor D. T., M.A., F.R S. 
Arnott, Neil, M.D., F.R.S. 
Ashburton, William Binsjham, Lord, D.C.L. 
Babbage, Charles, Esq., F.R.S. 
Babington, C. C, Esq., F.L.S. 
Bailv, Francis, Esq., F.R.S. 
Barker, George, Esq., F.R.S. 
Bengough, George, Esq. 
Bentham, George, Esq., F.L.S. 
Bigge, Charles, Esq. 
Blakiston, Pevton, M.D., F.R.S. 
Brewster, SirDavid, K.H., LL.D., F.R.S. 
Breadalbane, John, Marquis of, K.T., F.R.S. 
Brisbane, Lieut.-General Sir Thomas M., 

Bart., K.C.B., G.C.H., D.C.L., F.R.S. 
Brown, Robert, D.C.L., F.R.S., President of 

the Linnean Society. 
Brunei, Sir M. L, F.R.S. 
Buckland, Veiy Rev. William, D.D., Deau of 

Westminster, F.R.S. 
Burlington, William, Earl of, JLA., F.R.S., 
Cliancellor of the University of London. 
Bute, John, Marquis of, K.T. 
Carlisle, George William Frederick, Earl of, 

F.G.S. 
Carson, Rev. Joseph. 
Cathcart, Lieut.-General, Earl of, K.C.B., 

F.R.S.E. 
Chalmers, Rev. T., D.D., late Professor of 

Divinity, Edinburgh. 
Chance, James, Esq. 

Chester, John Graham, D.D., Lord Bishop of. 
Christie, Professor S. H., M.A., Sec. R.S. 
Clare, Peter, Esq., F.R.A.S. 
Clark, Rev. Professor, M.D., F.R.S. (Cam- 
bridge). 
Clark, Henry, ]\LD. 
Clark, G. T., Esq. 
Clear, WilUam, Esq. 

Gierke, Major Shadwell, K.IL, R.E., F.R.S. 
Clift, William, Esq., F.R.S. 
Colquhoun, J. C, Esq., ALP. 
Conybeare,Verv Rev.W. D., Dean of Llandaff, 

M.A., F.R.S. 
Corrie, John, Esq., F.R.S. 
Currie, William Wallace, Esq. 
Dalton, John, D.C.L., F.R.S. 
Daniell, Professor J. F., F.R.S. 
Dartmouth, WiUiam, Earl of, D.C.L., F.R.S. 
Darwin, Charles, Esq., F.R.S. 
Daubeny, Professor Charles G. B., M.D,, 

F.R.S. 
De la Beche, Sir Ilenrj- T., F.R.S., Director- 
General of the Geological Survey of the 
United Kingdom. 
Dillwyn, Lewis W., Esq., F.R.S. 



Driiikwater, J. E., Esq. 

Durham, Edward Maltby, D.D., Lord Bishop 

of, F.R.S. 
Egerton, Sir Philip de M. Grev, Bart., F.R.S. 
Eliot, Lord, M.P. 
Ellesmere, Francis, Earl of, F.G.S. 
Estcourt, T. G. B., D.C.L. 
Faraday, Professor, D.C.L., F.R.S. 
Fitzwilliam, Charles WilUam, Earl, D.C.L., 

F.R.S. 
Fleming, W., M.D. 
Fletcher, Bell, M.D. 
Forbes, Charles, Esq. 
Forbes, Professor Edward, F.R.S. 
Forbes, Professor J. D., F.R.S. 
Fox, Robert Were, Esq., F.R.S. 
Gilbert, Davics, D.C.L., F.R.S. 
Graham, Professor Thomas, ALA., F.R.S. 
Gray, John E., Esq., F.R.S. 
Grav, Jonathan, Esq. 
Gray, William, jun., Esq., F.G.S. 
Green, Professor Joseph Henrv, F.R.S. 
Greenough, G. B., Esq., F.R.S". 
Grove, W. R., Esq., F.R.S. 
Hallam, Heurv, Esq., M,k., F.R.S. 
Hamilton, W. J., Esq., Sec.G.S. 
Hamilton, Sir William R., Astronomer Royal 

of Ireland, M.R.LA. 
llarcourt. Rev. William Vernon, M.A., F.R.S. 
Hardwicke, Charles Philip, Earl of, F.R.S. 
Harford, J. S., D.C.L., F.R.S. 
Harris, Sir W. Snow, F.R.S. 
Harrowby, The Earl of. 
Hatfeild, William, Esq., F.G.S. 
Henslow, Rev. Professor, M.A., F.L.S. 
Henry, W. C, M.D., F.R.S. 
Herbert, Hon. and Very Rev. William, late 

Dean of Manchester, LL.D., F.L.S. 
Herschel,Sir John F.W.,Bart., D.C.L., F.R.S. 
Heywood, Sir Benjamin, Bart., F.R.S. 
Hevwood, James, Esq., M.P., F.R.S. 
Hodgkin, Thomas, M.D. 
Hodgkinson, Professor Eaton, F.R.S. 
Hodgson, Joseph, Esq., F.R.S. 
Hooker, Sir WilUam J., LL.D., F.R.S. 
Hope, Rev. F. W,, M.A., F.R.S. 
Hopkins, WilUam, Esq., M.A., F.R.S. 
Horner, Leonard, Esq., F.R.S., F.G.S. 
Hovendcn, V. F., Esq., M.A. 
Hutton, Robert, Esq., F.G.S. 
Hutton, WiUiam, Esq., F.G.S. 
Ibbetson, Capt. L. L. Boscawen, K.R.E., 

L)glis,'sirRobertH.,Bart.,D.C.L.,M.P.,F.R.S. 

Jameson, Professor R., F.R.S. 

Jenyns, Rev. Leonard, F.L.S. 

Jerrard, H. B., Esq. 

Johnston, Professor J. F. W., M.A., F.R.S. 

Keleher, William, Esq. 

Lardner, Rev. Dr. 

Lee, Robert, M.D., F.R.S. 

Lausdowne, Henry, Marquis of, D.C.L., F.R.S. 

Latham, R. G., M.D., F.R.S. 






MEMBERS OF COUNCIL. 



Lefevre, Right Hon. Charles Shaw, Speaker 

of the House of Commons. 
Lemon, Sir Charles, Bart., M.P., F.R.S. 
Liddell, Andrew, Esq. 
Lindley, Professor, Ph.D., F.R.S. 
Listowel, The Earl of. 
Lloyd, Rev. Bartholomew, D.D., late Provost 

of Trinity College, Dublin. 
Lloyd, Rev. Professor, D.D., Provost of 

Trinity College, Dublin, F.R.S. 
Lubbock, Sir John W., Bart., M.A., F.R.S. 
Lubv, Rev. Thomas. 
Lyell, Sir Charles, M.A., F.R.S. 
MacCuUagh, Professor, D.C.L., M.R.LA. 
Macfarlane, The Very Rev. Pri)icipal. 
MacLeay, William Sharp, Esq., F.L.S. 
IMacNeill, Professor Sir John, F.R.S. 
Meynell, Thomas, Jun., Esq., F.L.S. 
Miller, Professor W. H., M.A., F.R.S. 
Moillet, J. L., Esq. 
Moggridge, Matthew, Esq. 
Moody, T. H. C, Esq. 
Moodv, T. F., Esq. 
Morlev, The Earl of. 
Moseley, Rev. Heniy, M.A., F.R.S. 
Mount-Edgecumbe, Ernest Augustus, Earl of. 
Murchison, Sir Roderick L, G.C.S., F.R.S. 
Neill, Patrick, M.D., F.R.S.E. 
Nicol, D., M.D. 
Nicol, Rev. J. P., LL.D. 
Northumberland, Hugh,Duke of, K.G., M.A., 

F.R.S. 
Northampton, Spencer Joshua Alwj'ne, Mar- 
quis of, V.P.R.S. 
Norvrich, Edward Stanley, D.D., F.R.S., late 

Lord Bishop of. 
Ormerod, G. W., Esq., F.G.S. 
Orpen, Thomas Herbert, M.D. 
Owen, Professor Richard, M.D., F.R.S. 
Oxford, Samuel Wilberforce, D.D., Lord 

Bishop of, F.R.S., F.G.S. 
Osier, FoUett, Esq. 
Palmerston, Viscount, G.C.B., M.P. 
Peacock, Very Rev. George, D.D., Dean of 

Ely, F.R.S. 
Peel, Rt. Hon. Sur Robert, Bart., M.P., 

D.C.L., F.R.S. 
Pendarves, E., Esq., F.R.S. 
Phillips, Professor John, F.R.S. 
Porter, G. R., Esq. 
Powell, Rev. Professor, M.A., F.R.S. 
Prichard, J. C, M.D., F.R.S. 
Ramsay, Professor \V., M.A. 
Rennie, George, Esq., V.P.&Treas.R.S. 
Rennie, Sir John, F.R.S. 
Richardson, Sir John, M.D., F.R.S. 
Ritchie, Rev. Professor, LL.D., F.R.S. 
Robinson, Rev. J., D.D. 



Robinson, Rev. T. R.,D.D., M.R.LA. 

Robison, Sir John, late Sec.R.S.Edin. 

Roche, James, Esq. 

Roget, Peter Mark, M.D., F.R.S. 

Ross, Capt. Sir James C, R.N., F.R.S. 

Rosse, William, Earl of, M.R.LA., President 

of the Roval Society. 
Royle, Professor John F., M.D., F.R.S. 
Russell, James, Esq. 
Sabine, Lieut.- Colonel Edward, R.A., For. 

Sec.R.S. 
Sanders, WiUiam, Esq., F.G.S. 
San don. Lord. 

Scoresby, Rev. W., D.D., F.R.S. 
Sedgwick, Rev. Professor, M.A., F.R.S. 
Selby, Prideaux John, Esq., F.R.S.E. 
Smith, Lieut. -Colonel C. Hamilton, F.R.S. 
Staunton, Sir George T., Bart., M.P., D.C.L., 

F.R.S. 
St. David's, Connop Thirlwall, D.D., Lord 

Bishop of. 
Stevelly, Professor John, LL.D. 
Strang, John, Esq. 
Strickland, H. E., Esq., F.G.S. 
Sykes, Lieut.-Colonel W. H., F.R.S. 
S\Tnons, B, P., D.D., late Vice-Chancellor of 

the University of Oxford. 
Talbot, W. H. Fox, Esq., M.A., F.R.S. 
Tayler, Rev. J. J. 
Taylor, John, Esq., F.R.S. 
Taylor, Richard, jun., Esq., F.G.S. 
Thompson, William, Esq., F.L.S. 
Tindal, Captain, R.N. 
Traill, J. S., M.D. 
Turner, Edward, M.D., F.R.S. 
Turner, Samuel, Esq., F.R.S., F.G.S. 
Turner, Rev. W. 
Vigors, N. A., D.C.L., F.L.S. 
Vivian, J. H., M.P., F.R.S. 
Walker, James, Esq., F.R.S. 
Walker, Joseph N., Esq., F.G.S. 
Walker, Rev. Robert, M.A., F.R.S. 
Warburton, Henry, Esq., M.A., M.P., F.R.S. 
Washington, Captain, R.N. 
West, William, Esq., F.R.S. 
Wharncliffe, John Stuart, Lord, F.R.S. 
Wheatstone, Professor, F.R.S. 
Whewell, Rev. William, D.D., F.R.S., Master 

of Trinity College, Cambridge. 
Williams, Professor Charles J.B.,M.D.,F.R.S. 
Willis, Rev. Professor, JLA., F.R.S. 
Wills, William. 

Winchester, Jokn, Marquis of. 
Woollcombe, Henry, Esq., F.S.A. 
Wrotteslev, John, Lord, M.A., F.R.S. 
Yarrell, WilUam, Esq., F.L.S. 
Yarborough, The Earl of, D.C.L. 
Yates, James, Esq., M.A., F.R.S. 



BRITISH ASSOCIATION FOR THE 



THE GENERAL TREASURER'S ACCOUNT from 8th of August 

RECEIPTS. 

£ s. d. £ s. d. 

Life Compositions at Swansea 30 

Annual Subscriptions at Swansea and since 150 

Associates' at Swansea 376 

Ladies' Tickets at Swansea .-.•• 197 

Book Compositions 6 

Dividends on Stock 116 10 1 

Saleof Stock (£1000 three per cent. Consols) 917 9 2 

From Sale of Publications : — 

Of the 2nd volume 7 2 

3rd „ 1 8 

4th , 14 4 

5th „ 13 2 

6th „ 2 2 11 

7th , 2 6 

8th „ 3 4 

9th 1 18 

10th 3 7 6 

11th „ 1 19 11 

12th „ 3 9 

13th 5 12 

]4th „ 5 4 

15th „ 15 10 

16th „ 80 

17th , 6 

British Association's Catalogue of Stars 28 1 10 

Lalande's Catalogue of Stars 9 8 2 

Lacaille's Catalogue of Stars 1 16 5 

Lithograph Signatures 15 



168 3 6 



£1961 2 9 



JAMES HEYWOOD, 1 

G. R. PORTER, )■ Auditors. 

J. W. GILBART, J 



ADVANCEMENT OF SCIENCE. 



£ 


s. 


d. 


9 


7 


10 


287 


1 


9 


644 


6 


8 


500 









ISiS (at Swansea) to 12th of September 1849 (at Birmingham). 

PAYMENTS. 

£ 8. d. 

To Balance brought on from last Account 

For Sundry Printing, Advertising, Expenses of the Meeting at 
Swansea, and Sundry Disbursements made by the General 

and Local Treasurers 

Printing, &c. the 16th vol. (17th Report) 

Salaries, Assistant General Secretary and Accountant, 18 months 
Paid by order of Committees on Account of Grants for Scientific 
purposes : — 

Electrical Observations at Kev? 50 

Vitality of Seeds 5 8 1 

Acid on the Growth of Plants 5 

Registration of Periodical Phsenomena 10 

Bills on Account of Anemometrical Observations 13 9 

Maintaining the Establishment at Kew Observatory ; — 

Balance of Grant of 1847 20 15 7 

Part of Grant of 1848 55 6 10 

Balance in the Banker's hands 335 13 4 

Ditto in General and Local Treasurers' hands 24 13 8 



83 17 1 



76 2 5 




£1961 2 9 



OFFICERS AND COUNCIL. 



OFFICERS AND COUNCIL, 1849-50, 



Trustees (}}erma}ienl).—i:\v Roderick Impey Murcliison, G.C.S'.S., F.R.S. 
John Taylor, Esq., F.R.S. The Very Rev. George Peacock, D.D., Dean 
of Ely, F.R.S. 

President.— The Rev. T. Romney Robinson, D.D., M.R.I.A., F.R.A.S. 

Vice-Presidents. — The Earl of Harro'-vby. The Lord Bishop of Manchester. 
The Lord Wrotteslev, F.R.S. The Right Hon. Sir Robert Peel, Bart., D.C.L., 
F.R.S. Sir David 'Brewster, LL.D., F.R.S. Charles Darwin, Esq., M.A., 
F.R.S. M. Faraday, Esq., D.C.L., F.R.S. Rev. Robert Willis, M.A., F.R.S. 

President Elect.— Sir David Brewster, K.H., D.C.L., LL.D., F.R.S., 
V.P.R.S.E. 

Vice-Presidents Elect.— The Rt. Hon. The Lord Provost of Edinburgh. 
The Earl of Cathcart, K.C.B., F.R.S.E. The Earl of Rosebery, K.T., 
D.C.L., F.R.S. Right Hon. David Boyle, Lord Justice Genera], F.R.S.E. 
General Sir Thomas M. Brisbane, Bart., K.C.B., G.C.H., D.C.L., F.R.S., 
Pres. R.S.E. The Very Rev. John Lee, D.D., V.P.R.S.E., Principal of the 
University of Edinburgh. W. P. Alison, M.D., V.P.R.S.E., Prof, of the 
Practice of Physic in the University of Edinburgh. James D. Forbes, F.R.S., 
Sec. R.S.E., Professor of Natural Philosophy in the University of Edinburgh. 

General Secretaries. — Lieut. -Col. Sabine, R.A., For. Sec. R.S., Woolwich. 
John F. Royle, M.D., F.R.S., Prof, of Botany in King's College, London. 

Assistant General Secretary. — John Phillips, Esq., F.R.S., York. 
General Treasurer. — John Taylor, Esq., F.R.S., 6 Queen Street Place, 
Upper Thames Street, London. 

Local Secretaries. — Rev. Philip Kelland, A.M., Professor of Mathematics 
in the University of Edinburgh. John H. Balfour, M.D., Professor of Botany 
in the University of Edinburgh. James Tod, Esq., F.R.S.E., Secretary to 
the Society of Arts for Scotland. 

Local Treasurer. — William Brand, Esq. 

Council. — Professor Ansted. Sir H. T. De la Beche. Sir P. G. Egerton, 
Bart. Prof. E. Forbes. Prof. T. Graham. W. R. Grove, Esq. J. P. Gassiot, 
Esq. W^, J. Hamilton, Esq. James Hey wood, Esq. W. Hopkins, Esq. 
Leonard Horner, Esq. Robert Hulton, Esq. Capt. Ibbetson. Dr. R. G. 
Latham. Sir Charles Lemon, Bart. Sir Charles Lyell. Vice-Admiral Sir 
C. Malcolm. Prof. Owen. G. R. Porter, Esq. Col. Reid. F. Ronalds, Esq. 
J. Scott Russell, Esq. William Spence, Esq. Lieut. -Co!. Sykes. Prof. 
Wheatstone. Rev. Prof. Willis. 

Local Treasurers. — W. Gray, Esq., York. Rev. E. Hill, Oxford. 
C. C. Babington, Esq., Cambridge. William Brand, Esq., Edinburgh. 
J. H. Orpen, LL.D., Dublin. Professor Ramsay, Glasgow. William San- 
ders, Esq., Bristol. G. W. Ormerod, Esq., Manchester. James Russell, 
Esq., Birmingham. J. Sadleir Moody, Esq., Southampton. John Gwyn 
Jeffreys, Esq., Swansea. 

Auditors. — James Heywood, Esq. G. R. Porter, Esq. J. W. Gilbart, Esq. 



OFFICERS OF SECTIONAL COMMITTEES. XV 

OFFICERS OF SECTIONAL COMMITTEES AT THE 
BIRMINGHAM MEETING. 

SECTION A. MATHEMATICAL AND PHYSICAL SCIENCE. 

President. — William Hopkins, Esq., F.R.S. 

Vice-Presidents.— Hev. E. H. Giffbrd. Sir W. S. Harris, F.R.S. J. C. 
Adams, Esq., F.R.S. The Dean of Ely, F.R.S. 

Secretaries. — Professor Stevelly. G. G. Stokes, M.A. W. Ridout Wills, 
Esq. 

SECTION B. — CHEMICAL SCIENCE, INCLUDING ITS APPLICATION TO 
AGRICULTURE AND THE ARTS. 

President.— John Percy, Esq., M.D., F.R.S. 

Vice-Presidents. — Professor Ajijohn, M.R.I. A. Professor Graham, F.R.S. 
Richard Phillips, Esq., F.R.S. Dr. Miller, F.R.S. Dr. Andrews, F.R.S. 
John P. Gassiot, Esq., F.R.S. 

Secretaries. — George Shaw, Esq. Robert Hunt, Esq. 

SECTION C. GEOLOGY AND PHYSICAL GEOGRAPHY. 

President Sir Charles Lyell, F.R.S., Pres. G.S. 

Vice-Presidents.— Sir H. T. De la Beche, C.B., F.R.S, Rev. A. Sedg- 
wick, F.R.S., Professor of Geology, Cambridge. The Very Rev. the Dean 
of VVestminster, F.R.S. Leonard Horner, Esq., F.R.S. Sir Roderick I. 
Murchison, F.R.S. &c. (for Geography). 

Secretaries. — J. Beete Jukes, Esq., F.G.S. Professor A. C. Ramsay, 
F.R.S. Professor Oldham, F.R.S. 

SECTION D. ZOOLOGY AND BOTANY, INCLUDING PHYSIOLOGY. 

President. — Wm. Spence, Esq., F.R.S. 

Vice-Presidents. — J. Hodgson, Esq., F.R.S. J. Gwyn Jeffreys, Esq., 
F.R.S. Professor H. Wentworth Acland, F.R.S. Dr. Roget, F.R.S. C. 
C. Babington, Esq., F.R.S. Professor E. Forbes, F.R.S. Professor W. 
P. Alison, M.D. R. Fowler, M.D., F.R.S. 

Secretaries. — Dr. Lankester, F.R.S. Dr. Russell. 

SUBSECTION OF ETHNOLOGY. 

Vice-Presidents. — Sir Charles Malcolm. Dr. Hodgkin. 
Secretary. — Dr. R. G. Latham, F.R.S. 

SECTION F. STATISTICS. 

President. — Lord Lyttleton. 

Vice-Presidents — Col. Sykes, F.R.S. G. R. Porter, Esq., F.R.S. Da- 
venport Hill, Esq, James Heywood, Esq., M.P., F.R.S. 

Secretaries. — Professor Hancock. Dr. Finch. F. G. P. Neison, Esq. 

SECTION O. — MECHANICAL SCIENCE, 

President. — Robert Stephenson, Esq., M.P., F.R.S. 
Vice-Presidents.~U. Wollaston Blake, Esq., F.R.S. William Fairbairn, 
Esq. Follett Osier, Esq. Thomas Webster, Esq., F.R.S. 
Secretaries William P. Marshall, Esq. Charles Manby, Esq. 



REPORT — 1849. 



CORRESPONDING MEMBERS. 



Professor Agassiz, Cambridge, Mas- 
saclnisetts. 

M. Arago, Paris. 

Dr. A. D. Bache, Philadelphia. 

Professor H. von Boguslawski, Bres- 
lau. 

Monsieur Boutigny (d'Evreux), Paris. 

Professor Braschmann, Moscow. 

Chevalier Bunsen. 

Charles Buonaparte, Prince of Canino. 

M. De la Rive, Geneva. 

Professor Dove, Berlin. 

Professor Dumas, Paris. 

Dr. J. Milne-Edwards, Paris. 

Professor Ehrenberg, Berlin. 

Dr. Eisenlohr, Carlsruhe. 

Professor Encke, Berlin. 

Dr. A. Erman, Berlin. 

Professor Esmark, Christiania. 

Professor G. Forchhamrner, Copen- 
hagen. 

M. Frisian!, Milan. 

Professor Henry, Princeton, United 
States. 

Baron Alexander von Humboldt, 
Berlin. 

M. Jacobi, St. Petersburg. 

Professor Jacobi, Konigsberg. 



Professor Kreil, Prague. 

M. Kupffer, St. Petersburg. 

Dr. Langberg, Christiania. 

M. Leverrier, Paris. 

Baron de Selys-Longchamps, Liege. 

Dr. Lamont, Munich. 

Baron von Liebig, Giessen. 

Professor Link, Berlin. 

Professor Matteucci, Pisa. 

Professor von Middendorff, St. Pe- 
tersburg. 

Professor Nilsson, Sweden. 

Dr. Qilrsted, Copenhagen. 

Chevalier Plana, Turin. 

M. Quetelet, Brussels. 

Professor Pliicker, Bonn. 

Professor C. Ritter, Berlin. 

Professor H. D.Rogers, Philadelphia. 

Professor H. Rose, Berlin- 
Professor Schumacher, Altona. 

Baron Senftenberg, Bohemia. 

Dr. Siljestrom, Stockholm. 

M. Struve of St. Petersburg. 

Dr. Svanberg, Stockholm. 

Dr. Van der Hoven, Leyden. 

Baron Sartorius von Waltershausen, 
Gotha. 

Professor Wartmann, Lausanne. 



Report of the Proceedings of the Council in 1848-49, as presented 

TO THE General Committee at Birmingham, Wednesday, September 

12, 1849. 

1, With reference to the subjects referred to the Council by the General 
Committee assembled at Swansea, the Council have to report — 

1st. That they communicated the recommendation of the General Com- 
mittee, for the continuance of the Magnetical and Meteorological Observa- 
tory at Toronto to the 31st of December, 1850, to Lord John Russell, 
through the President, the Marquis of Northampton. They have the plea- 
sure of stating that the Observatory has been continued. 

2nd. Pursuant to the request of the General Committee, the Council have 
taken into consideration the expediency of inserting in the Rules of the 
British Association a paragraph to the effect that those gentlemen who have 
held the office of President of the Association should subsequently be ex- 
officio members of the Council ; and the Council now recommend that a 
paragraph to that effect should be inserted in the Rules of the Association. 

3rd. The sum of 100/., placed by the General Committee at the disposal 
of the Council for the disbursements connected with the Kew Observatory, 
has sufficed, under Mr. Ronalds's general superintendence, for the mainte- 
nance of the Observatory in the past year as a depository for the books and 
instruments belonging to the Association ; and also for the preparation of 
the self-registering magnetical instruments, on Mr. Ronalds's plan, for the 



REPORT OF THE COUXCiL. XVH 

Toronto Colonial Observatory. Mr. Birt lias completed the reduction and 
discussion of the series of electrical observations made at Kew ; and Mr. 
Ronalds has drawn up a Report describing the modifications and improve- 
ments which he has introduced in the self-registering apparatus during the 
last year. Both these Reports will be read to Section A. preparatory to a 
consideration of any further recommendation which it may appear desirable 
to make for the continued maintenance of the Observatory. In connexion 
with this subject, the Council liave great pleasure in announcing to the 
General Committee, that Her Majesty's Government, on the joint application 
of the Marquis of Northampton and Sir John Herschel, have granted to 
Mr. Ronalds a pecuniary recompense of £250 for the invention of his method 
of constructing self-registering magnetical and meteorological apparatus. It 
will be recollected by many members of the General Committee that the 
subject of self-registering instruments was discussed at the meeting of the 
British Association at Cambridge, in 1845, upon the application for a grant 
of money from the funds of the Association to enable Mr. Ronalds to com- 
plete an apparatus for that purpose at Kew ; and that a recommendation 
was made on that occasion by the Association to Government — which recom- 
mendation was concurred in by the President and Council of the Royal 
Society — of the expediency of encouraging, by specific pecuniary rewards, 
the improvement of self-recording magnetical and meteorological apparatus. 
As the grant to Mr. Ronalds has been made in consequence of that 
original recommendation and the favourable reply that was returned to it, 
and as the apparatus itself has been constructed, and its successful operation 
shown at the Observatory of the Association, of which Mr. Ronalds is the 
Honorary Superintendent, the Council have deemed it proper to make this 
formal, and as they are sure acceptable, announcement of the favourable 
reception which has been given to the application on Mr. Ronalds's behalf; 
but they are glad, at the same time, to take the opportunity of expressing 
the satisfaction with which they have learned that the ingenious invention of 
Mr. Brooke, for similar purposes, has also received a pecuniary recompense 
from the Government. 

II. The Council regret that they are still unable to announce the publica- 
tion either of Professor Edward Forbes's Researches in the ^gean Sea, or 
of the Mountjoy Observations, for which purposes grants of public money 
have- been sanctioned by Her Majesty's Government at the recommendation 
of the British Association. 

III. The Council have added the following names to the list of Corre- 
sponding Members of the British Association: — 

Professor Pliicker of Bonn. 

Dr. Siljestrom of Stockholm, 

Prof. H. D. Rogers of Philadelphia. 

IV. Prof. Dove, of Berlin, Corresponding Member of the British Asso- 
ciation, having offered to supply the Association with as many copies as 
might be desired of his Maps of the Monthly Isothermal Lines of the Globe, 
founded upon the Temperature Tables printed in the volume of the Reports 
of the British Association for 1848, which maps have been partly engraved 
and partly lithographed at the expense of the Royal Academy of Sciences 
at Berlin, the Council directed that Prof. Dove should be requested to supply 
the Association with 500 copies, on the understanding that the Association 
should pay for the paper and for taking off the impressions ; and that the 
copies thus furnished should be sold, under the direction of the oflficers, to 
Members of the Association at cost price, with the translation of a report 

1819. c 



Xvlii REPORT — 1849. 

from Prof. Dove, explanatory of the Maps and of the more obvious conclu- 
sions deduced from them. The Maps have been completed, but from acci- 
dental circumstances the packet containing the first 200 copies, prepared for 
the Association, has not yet been despatclied from Berlin, and cannot be 
expected to reach England until after the Meeting at Birmingham is over ; 
but copies of the Maps and Report will be forwarded immediately they 
arrive to Members who may be desirous of purchasing them, and who give 
their names for that purpose in the Reception Room. The cost of each 
copy will be 5s. for the three Maps. 

V. The Council has directed that the following additions should be made 
to the Regulations, according to which the volumes of the Reports are 
distributed to the Members : — 

1. That Members who have formerly paid £5 as a life composition, and 
shall at any future time pay an additional sum of £5, shall be entitled to 
receive (gratis) the volumes of the Transactions which shall be published 
after the date of such additional payments. 

2. That Members shall have the opportunity of purchasing any of the 
already published volumes of the Association, of which more than 100 copies 
remain, at half the price at which the volumes were issued to the public. 

VI. Tlie Council have great pleasure in submitting to the General Com- 
mittee tiie following list of invitations, from which the General Committee 
will have to select the place of meeting of the Association in 1850, 

a. Invitations received at Swansea by the General Committee, and which 
stood over after the selection of Birmingham, 1849 : — 

From Ipswich, for 1849; signed by the High Sheriff, the Bishop of 

Norwich, and eighty gentlemen of the Eastern Counties. 
From Bath, for 1850 ; signed by the Mayor. 
From Derby, for 1850. 

6. Invitations received since the Swansea Meeting and communicated to 
the Council : — 

From Edinburgh, for 1850; from the Lord Provost, Magistrates and 

Council ; from the Senatus Academicus; and from the Royal Society of 

Edinburgh. 
From Belfast for 1850 or 1851; from the Town Council; the Royal 

Academical Institution ; the Natural History and Philosophical Society; 

and from the Harbour Commissioners. 
From Manchester, for 1852 ; from the Royal Institution: the Geological 

Society; the Natural History Society ; the School of Design ; and the 

Mechanics' Institution. 
From Hull, for an early meeting ; from the Literr.ry and Philosophical 

Institution, 
. VII. The Council have received and submit to the General Committee 
the following letter from Lieut, -Col. Sabine : — 

" To the President and Council of the British Association. 

" Gentlemen, — I beg leave to acquaint you that it is my intention, at the 
Meeting of the Association at Birmingham, to resign into the hands of the 
General Commtttec the office of General Secretary, with which I have been 
honoured, by annual re-election, for ten successive years. 

" I have formed this determination, not from any occurrence which has 
rendered me less willing than heretofore, to undertake the duties and 
responsibilities of that office, or to make the sacrilice of time, convenience, 
and of other interests which it requires ; nor from a fear that the kindness 
and indulgence with which my endeavours to discharge its duties have been 



REPORT OF THE COUNCIL. XIX 

regarded by the General Committee, by the Council, and by the Members 
of the Association generally, is in any danger of being exhausted ; but from 
the opinion which I entertain that, as a general principle, the disadvantages 
of such offices being held by the same individual for several years outweigh 
the advantages, — and that in my own particular case it is safer to act on the 
general principle than to fancy myself an exception to it. 

" I am aware that in Societies in which, as in the British Association, the 
Presidency is held but for a single year, it may be desirable that the next 
principal executive officer should be more permanent than when tlie Presi- 
dency is held for a longer period. But the office of General Secretary of 
the British Association for the Advancement of Science is one which confers 
lionour and distinction on the individual who holds it, not only in Britain, 
but in all countries where science is enjoyed or its advancement desired; 
and as such it may justly be regarded as an object of reasonable ambition. 
When the Meeting at Birmingham shall have concluded, I shall have com- 
pleted a cycle of ten years, and I consider that the time will then be fully 
arrived when, with propriety as regards myself, and with a due consideration 
of the interests of others, and pre-eminently those of the Association itself, 
T may resign the trust with which I have been honoured, into the hands 
from which I received it. 

" I have thought it my duty to give you this early intimation of my inten- 
tion, as it will probably be considered right that the recommendation of my 
successor should proceed from the Council. 

" I have, &c., 

" Edward Sabine." 



Recommendations adopted by the General Committee at the 
Birmingham Meeting in September 184 9. 

Involving Application to Government. 

That an application be made to Her Majesty's Government, to establish 
a Reflector not less than 3 feet in diameter, at the Observatory at the Cape 
of Good Hope, and to make such additions to the staff of the Observatory 
as may be necessary for its eftbctual working ; and that the President be 
requested to communicate with Lord Rosse, Sir J. Herschel, the Astronomer 
Royal, Sir T. Brisbane, and Dr. Lloyd, on the subject, and to obtain the 
concurrence in the application, of the Royal and Astronomical Societies of 
London, the Royal Society of Edinburgh, and the Royal Irish Academy. 

That an application be made to the Master-General of the Ordnance, to 
have the Levels of the Ordnance Survey of Ireland connected to the Mean 
SeaLevel, as deduced by Mr. Airy (Astronomer Royal) from the Tide Obser- 
vations round that Island ; and that the President, Trustees and Officers of 
the British Association, and the President of the Royal and Geological So- 
cieties of London, and the Royal Irish Academy, be requested to make this 
application. 

That application be made to the Master-General of the Ordnance, to have 
the British Arc of the Meridian published in its full extent, and that the 
President, Trustees and Officers of the British Association, the Royal So- 
cieties of London and Edinburgh, the Royal Irish Academy, and the Royal 
Astronomical Society, be requested to make such application. 

That the Members of the British Association who are also Members of 
the Legislature, be requested to act as a permanent Committee, to watch over 
the interests of Science, and to inspect the various measures from time to time 
introduced into Parliament likely to affect such interests ; and that the Mar- 



XX REPORT — 1849, 

quis of Noitliampton, Lord Rosse, Lord Wrottesley, Lord Adare, M.P., 
Sir Pliilip Egerton, M.P., and Sir C. Lemon, M.P., be requested to organize 
such Connmittee. 

Involving Grants of Money, 

Sir John F. W. Herschel having reported that the Meteorological Obser- 
vations made at Kew are peculiarly valuable, and likely to produce the most 
important results, the Committee resolved that the sum of £250 be voted for 
the continuance of that establishment for the ensuing year ; and that the 
sum be placed at the disposal of the Council, to whom the requisite arrange- 
ments are entrusted. 

That three standard Barometers and other Meteorological Instruments be 
sent out to the British Consul- General at the Azore Islands, with the view 
of encouraging that gentleman (Mr. C. Hunt) to pursue his Meteorological 
Observations at tiie several Islands at which he has British Vice-Consuls ; 
and that Colonel Reid, Colonel Sabine, Sir W. S. Harris, and Professor 
Phillips be a Committee for carrying out the above objects, with the sum of 
£25 at their disposal for the purpose. 

Dr. Percy and Professor Miller, — To continue Researches on Crystalline 
Slags, with £10 at their disposal. 

Dr. Schunck. — To continue Investigations on Colouring Matters, with £5 
at his disposal. 

Dr. Smith (Manchester). — To continue Investigations on the Air and 
\Yater of Towns, with £5 at his disposal. 

R. Mallet, Esq., Rev. Dr. Robinson, Rev. Prof. Lloyd, and Prof. Oldham. — 
To determine by Instruments the Elements of the Transit of Natural and 
Artificial Earthquake Waves, with £50 at their disposal. 

Dr. Lankester, Professor Owen, and Mr. R. Taylor. — On Periodical 
Phaenomena of Animals and Vegetables, with £10 at tlieir disposal. 

Mr. Strickland, Dr. Daubeny, Professor Liiidley, Professor Henslow. — 
On Vitality of Seeds, with £6 at their disposal. 

Professor E. Forbes and a Committee. — To procure a Report on British 
Annelida, with £10 at their disposal. 

Not involving Grants of Money, or Applications to Government. 

That Professor Powell's Communication on Meteors be printed among 
the Reports, and be continued from time to time. 

That a Committee be appointed for each Section, consisting of the Pre- 
sident of the Section, with two other Members to be named by him (and the 
General and Assistant General Secretaries ix officio), for the purpose of 
revising theRecommendations which have from time to time been sanctioned 
by the Association, on subjects which are taken into consideration by the Sec- 
tion, respectively, and of reporting to the Council the steps which, in their 
opinion, should now be taken to give them the effect which Science requires. 

That the Council be authorized to institute such steps as appear requisite 
to carry out this object. 

That Meteorologists should be invited to communicate as they occur, to 
the Association, through the Assistant General Secretary, any Abnormal or 
other Meteorological Phaenomena of interest observed by them. 

That a Committee, consisting of Lord Adare, Dr. Robinson, Professor 
Forbes, Colonel Sabine, Colonel Reid, Professor Powell, Professor Challis, 
Sir J. Lubbock, Professor Chevalier, Mr. Birt, Mr. A. Smith, Mr. J. A. 
Brown, and Professor Phillips, with power to add to their number, be ap- 
pointed to consider the best mode of promoting the observation of Luminous 
Meteors and Auroras ; and tliat observers be requested to communicate with 
Professor Powell on Meteors, and with Professor Phillips on Auroras. 



RESEARCHES IN SCIENCE. XXI 

That a Committee, composed of Sir H. T. De la Beclie, Sir W. Hooker, 
Dr. Daubeny, Mr. Henfrey, and Mr. Hunt, be requested to continue their 
investigations on the action of Carbonic Acid on the growth of ferns. 

That Mr. R. Hunt be requested to furnish to the next Meeting a Report 
on the present state of our knowledge of the Chemical Action of the Solar 
Radiations. 

That Mr. Mallet be requested to complete his Report on the Statical and 
Dynamical effects of Earthquakes. 

That Professor E. Forbes, Dr. Playfair, and Dr. Carpenter, be requested 
to report on the Perforating Apparatus of Mollusca. 

That the subject of Luminosity in Living Animals be recommended to the 
attention of Naturalists, with a view to determine the causes of such lumi- 
nosity, the circumstances, the species of animals which possess it, and the 
state of knowledge on the subject ; and that Mr. Darwin be requested to 
collect and receive observations on the subject. 

That Mr. Henfrey be requested to report on the Hybridism of Plants. 

That G. R. Porter, Esq., Colonel Sykes, Mr. Tooke, Professor Longfield, 
Mr. Lawson, and Professor Hancock, be requested to prepare a Report on 
the State and Progress of Statistics. 

That the Communication of Lord Rosse, on Nebulae, be printed entire 
among the Reports. 

That Mr. Nasmyth be requested to prepare a Report on the Use and Re- 
lative value of the Hydrocarbons as a Lubricating Material ; and that Dr. 
Playfair be requested to co-operate with him. 

That it be recommended to the Council to consider of tlie propriety of 
reducing the number of copies to be printed of the next volume, and that 
the Council be authorized to arrange for the proper distribution of- the un- 
sold copies of previously published volumes. 

Synopsis of Grants of Money apirropriated to Scientific Objects by the 
General Committee at the Birmingham Meeting in September 1849, 
with the Name of the Member, who alone or as the First of a 
Committee, is entitled to draw for the Money. 

Kew Observatory. £ s. d. 

At the disposal of the Council for defraying Expenses 250 

Mathematical and Physical Science. 
Reid, Colonel — Meteorological Observations at the Azore 

Islands 25 

Chemical Science. 

Percy, Dr. — Researches on Crystalline Slags 10 

ScHUNCK, Dr. — Investigations on Colouring Matters 5 

Smith, Dr. — Investigations on the Air and Water of Towns ... 500 

Geology. 
Mallet, R. — To determine by instruments the Elements of the 

Transit of Natural and Artificial Earthquake Waves .... 50 

Natural History, 

Strickland, H. E. — Vitality of Seeds 6 

LANKESTER,Dr. — Periodical Phasnomena of Animals and Vege- 
tables 10 

Forbes, Prof. E. — Report on British Annelida 10 

Total of Grants £371 



REPORT — 1849. 



General Statement of Sums which have been paid on Account of Grants for 
Scientific Purposes. 



1834. 



Tide Discussions 



£ 
20 







1835. 

Tide Discussions 62 

BritishFossil Ichthyology 105 

£167 



1836. 
Tide Discussions .... 163 
BritishFossil Ichthyology 105 
Thermometiic Observa- 
tions, &c 50 

Experiments on long- 
continued Heat .... 17 1 

Rain Gauges 9 13 

Refraction Experiments 15 

Lunar Nutation 00 

Thermometers 15 6 

£43l~U 



1837. 
Tide Discussions 284 



1 



Chemical Constants 



24 13 




Lunar Nutation 70 

Observations on Waves. 100 12 

Tides at Bristol 150 

Meteorology and Subter- 
ranean Temperature . 89 5 
VitrificationExperiments 150 
Heart Experiments. .. . 8 4 
Barometric Observations 30 
Barometers 11 



Ij 



1838. 

Tide Discussions 29 

British Fossil Fishes . . 100 
Meteorological Observa- 
tions and Anemometer 

(construction) 100 

Cast Iron (strengtii of) . 60 
Animal and Vegetable 
Substances (preserva- 
tion of) 19 



£918 14 6 



1 10 



Carried forward £308 1 10 



£ «. d. 
Brought forward 308 110 

Railway Constants .... 41 12 10 

Bristol Tides 50 

Growth of Plants .... 

Mud in Rivers 

Education Committee . 

Heart Experiments. . . 

Land and Sea Level . 

Subterranean Tempera 
ture 

Steam-vessels 100 

Meteorological Commit- 
tee 31 9 5 

Thermometers 16 4 



75 








3 


6 


6 


50 








5 


3 





267 


8 


7 



8 6 



1839. 
Fossil Ichthyology .... 110 
Meteorological Observa- 
tions at Plymouth . . 63 
Mechanism of Waves . . 144 

Bristol Tides '■iH 

Meteorology and Subter- 
ranean Temperature . 21 
VitrificationExperiments 9 
Cast Iron Experiments. 100 
Railway Constants .... 28 
Land and Sea Level . . 274 
Steam-Vessels' Engines. 100 
Stars in Histoire Celeste 331 

Stars in Lacaille 11 

Stars in R.A.S. Catalogue 
Animal Secretions .... 
Steam-engines in Corn 

wall 

Atmospheric Air 16 

Cast and Wrought Iron. 40 
Heat on Organic Bodies 5 
Gases on Solar Spec- 
trum 22 

Hourly Meteorological 
Observations, Inver- 
ness and Kingussie . . 49 

Fossil Reptiles 118 

Mining Statistics 50 

£\bQ5 



10 



50 



£956 12 2 







10 





2 





18 


6 


11 





4 


7 








7 


2 


1 


4 








18 


6 








16 


6 


10 











1 






















7 


8 


2 


9 








11 






GENEBAIi STATEMENT. 



& s. d. 



1840. 








Bristol Tides 


100 








Subterranean Tempera- 








ture c 


13 
18 


13 
19 


fi 


Heart Experiments. . . . 





Lungs Experiments . . 


8 


13 





Tide Discussions 


50 








Land and Sea Level . . 


6 


11 


1 


Stars (Histoire Celeste) 


242 


10 





Stars (Lacaille) 


4 


15 





Stars (Catalogue) .... 


264 








Atmospheric Air 


15 


15 







10 








Heat on Organic Bodies 


7 








MeteorologicalObserva- 








tions 


52 


17 


(\ 


Foreign- Scientific Me- 




moirs 


112 
100 


1 




^^ 


Working Population . . 





School Statistics 


50 








Forms of Vessels .... 


184 


7 





Chemical and Electrical 








Phenomena 


40 








Meteorological Observa- 








tions at Plymouth . . 


80 








Magnetical Observations 


185 


13 


9 


£1546 


16 


4 



1841. 

Observations on Waves. 30 
Meteorologyand Subter- 
ranean Temperature . 8 8 

Actinometers 10 

Earthquake Shocks .. 17 7 

Acrid Poisons 6 

Veins and Absorbents. . 3 

Mud in Rivers 5 

Marine Zoology 15 12 

Skeleton Maps 20 

Mountain Barometers. . 6 18 

Stars (Histoire Celeste). 185 

Stars (Lacaille) 79 5 

Stars (Nomenclature of) 17 19 

Stars (Catalogue of) . . 40 

Water on Iron 50 

MeteorologicalObserva- 

tions at Inverness . . 20 
Meteorological Observa- 
tions (reduction of).. 25 

Carried forward £539 10 



£, s. d- 

Brought forward 539 10 8 

Fossil Reptiles 50 

Foreign Memoirs .... 62 
Railway Sections .... 38 1 6 
Forms of Vessels .... 193 12 
Meteorological Observa- 
tions at Plymouth . . 55 
Magnetical Observations 61 18 8 
Fishes of the Old Red 

Sandstone 100 

Tides at Leith 50 

Anemometer at Edin- 
burgh 69 1 10 

Tabulating Observations 9 6 3 

Races of Men 5 

Radiate Animals. .... . 200 

£1235 10 11 

1842. 
Dynamometric Instru- 
ments 113 11 2 

Anoplura Britanniae .. 52 12 

Tides at Bristol 59 8 

Gases on Light 30 14 7 

Chronometers 26 17 6 

Marine Zoology 1 5 

British Fossil Mammalia 100 

Statistics of Education. . 20 
Marine Steam-vessels' 

Engines 28 

Stars (Histoire Celeste) 59 
Stars (British Associa- 
tion Catalogue of) ..110 

Railway Sections 161 10 

British Belemnites .... 50 
Fossil Reptiles (publica- 
tion of Report) 210 

Forms of Vessels. ...... 180 

Gal vanic Experiments on 

Rocks 5 8 6 

Meteorological Experi- 
ments at Plymouth. . 68 
Constant Indicator and 
Dynamometric Instru- 
ments 90 

Force of Wind 10 

Light on Growth of Seeds 8 

Vital Statistics 50 

Vegetative Power of 

Seeds 8 1 11 

Carried forward £1442 8 8 



XXIV 



REPORT — 1849. 















12 


8 









£ s. d. 

Brought forward 1442 8 8 
Questions on Human 

Race 7 9 

£1449 17 8 

1843. 

Revision of the Nomen- 
clature of Stars .... 2 

Reduction of Stars, Bri- 
tish Association Cata- 
logue 25 

Anomalous Tides, Frith 
of Forth 120 

Hourly Meteorological 
Observations at Kin- 
gussie and Inverness 77 

Meteorological Observa- 
tions at Plymouth . . 55 

Whewell's Meteorolo- 
gical Anemometer at 
Plymouth 10 

Meteorological Observa- 
tions, Osier's Anemo- 
meter at Plymouth . . 

Reduction of Meteorolo- 
gical Observations . . 

Meteorological Instru- 
ments and Gratuities 

Construction of Anemo- 
meter at Inverness . . 

Magnetic Co-operation . 

Meteorological Recorder 
for Kew Observatory 

Action of Gases on Light 

Establishment at Kew 
Observatory, Wages, 
Repairs, Furniture and 
Sundries . .' 133 

Experiments by Captive 
Balloons 81 

Oxidation of the Rails 
of Railways 20 

Publication of Report on 
Fossil Reptiles .... 40 

Coloured Drawings of 
Railway Sections. ... 147 

Registration of Earth- 
quake Shocks 30 

Report on Zoological 
Nomenclature 10 



20 








30 








39 


6 





5(i 


12 


2 


10 


8 


10 


50 








18 


16 


1 





£ 


s. 


d. 


Brought forward 


977 


6 


7 


Uncovering Lower Red 








Sandstone near Man- 








chester 


4 


4 


6 


Vegetative Power of 










5 


3 


8 


Marine Testacea (Habits 




of) 


10 








Marine Zoology 

Marine Zoology 


10 
2 



14 



11 


Preparation of Report 
on British Fossil Mam- 










100 
20 









Physiological operations 
of Medicinal Agents 





Vital Statistics 


36 


5 


8 


Additional Experiments 
on theForms of Vessels 


70 








Additional Experiments 








on theForms of Vessels 


100 








Reduction of Observa- 








tions on the Forms of 








Vessels 


100 








Morin's Instrument and 








Constant Indicator . . 


69 


14 


10 


Experiments on the 
Strength of Materials 


60 








£1565 


10 


_2 



Carried forward £977 



4 


7 


8 

















18 


3 














6 


7 



1844. 

Meteorological O bserva- 
tions at Kingussie and 
Inverness 12 

Con)pletingObservations 

at Plymouth 35 

Magnetic and Meteoro- 
logical Co-operation. . 25 8 4 

Publication of the Bri- 
tish Association Cata- 
logue of Stars ^5 

Observations on Tides 
on the East Coast of 
Scotland 1 00 

Revision of the Nomen- 
clature of Stars.. 1842 2 9 6 

Maintaining the Esta- 
blishment in Kew Ob- 



servatory 

Instruments for Kew Ob- 



117 17 



servatory 56 7 3 

Carried forward £384 2 4 



GENERAL STATEMENT. 



XXV 



10 



15 



100 



23 



£ 
Brought forward 384 

Influence of light on 
Plants 

Subterraneous Tempera- 
ture in Ireland 

Coloured Drawings of 
Railway Sections. . . . 

Investigation of Fossil 
Fishes of the Lower 
Tertiary Strata .... 

Registering the Shocks 
of Earthquakes, 1842 

Researches into the 
Structure of Fossil 
Shells 

Radiata and Mollusca of 
the JEgean and Red 
Seas 1842 

Geographical distribu- 
tions of Marine Zo- 
ology 1842 

Marine Zoology of De- 
von and Cornwall .. 10 

Marine Zoology of Corfu 10 

Experiments on the Vi- 
tality of Seeds 9 

Experiments on the Vi- 
tality of Seeds. . 1842 8 

Researches on Exotic 
Anoplura 15 

Experiments on the 
Strength of Materials 100 

Completing Experiments 
on the Forms of Ships 100 

Inquiries into Asphyxia 10 

Investigations on the in- 
ternal Constitution of 
Metals 

Constant Indicator and 
Morin's Instrument, 
1842 



s. 
2 


d. 

4 














17 


6 








11 


10 



20 



100 



10 







3 

7 3 











50 



10 3 6 

£981 12 8 

1845. 

Publication of the Britisli 
Association Catalogue 
of Stars 351 14 G 

Meteorological Observa- 
tions at Inverness .. 30 18 11 

Magnetic and Meteoro- 
logical Co-operation IG 16 8 

Carried forward £399 10 1 



20 








10 








2 





7 


7 









£ s. d. 
Brought forward 399 10 1 

Meteorological Instru- 
ments at Edinburgh 18 11 9 

Reduction of Anemome- 
trical Observations at 
Plymouth 25 

Electrical Experiments 

at Kew Observatory 43 17 8 

Maintaining the Esta- 
blishment in Kew Ob- 
servatory 149 15 

For Kreil's Barometro- 

graph 25 

Gases from Iron Fur- 
naces 50 

Experiments on the Ac- 

tinograph 15 

Microscopic Structure of 
Shells 

Exotic Anoplura . . 1843 

Vitality of Seeds. .1843 

Vitality of Seeds. . 1844 

Marine Zoology of Corn- 
wall 10 

Physiological Action of 

Medicines 20 

Statistics of Sickness and 

Mortality in York . . 20 

Registration of Earth- 
quake Shocks . . 184 3 15 14 8 
£831 9 9 

1846. 

British Association Ca- 
talogue of Stars, 1844 211 15 

Fossil Fishes of the Lon- 
don Clay 100 

Computation of theGaus- 
sian Constants for 1839 50 

Maintaining the Esta- 
blishment at Kew Ob- 
servatory 146 16 

Experiments on the 
Strength of Materials 

Researches in Asphyxia 

Examination of Fossil 
Shells 

Vitality of Seeds.. 1844 

Vitality of Seeds. . 1845 

Marine Zoology of Corn- 
wall 

Carried forward £605 15 10 











60 





I 6 16 


2 


10 





2 15 


10 


7 12 


3 


10 






REPORT 1849. 



11 



£ s, d. 
Brought forward 605 15 10 

Marine Zoology of Bri- 
tain 10 

Exotic Anoplura. . 184i 25 

Expenses attendingAne- 
mometers 

Anemometers' Repairs . 

Researches on Atmo- 
spheric Waves .... 

Captive Balloons . . 1 SPL 

Varieties of the Human 
Race 1844 

Statistics of Sickness and 
Mortality at York . . 



3 3 
8 ly 



7 6 3 



. 12 

£685 16 



1847. 

Computation of theGaus- 

sian Constants fori 839 50 

HabitsofMarineAnimals 10 

Physiological Action of 

Medicines 20 

Marine Zoology of Corn- 
wall ." 10 

Researches on Atmo- 
spheric Waves 6 9 3 

Vitality of Seeds 4 7 7 

Maintaining the Esta- 
blishment at Kew Ob- 
servatory 107 8 6 

£•208 5 I 



£ s, d. 
1848. 

Maintaining the Esta- 
blishment at Kew Ob- 
servatory 171 15 11 

Researches on Atmo- 
spheric Waves .... 3 10 9 

Vitality of Seeds 9 15 

Completionof Catalogues 

of Stars 70 

On Colouring Matters . 5 

On Growth of Plants . . 15 

£S75 1 8 



1849. 

Electrical Observations 

at Kew Observatory 50 

Maintaining Establish- 
ment at ditto ...... 76 

Vitality of Seeds 5 

On Growth of Plants. . 5 

Registration of Periodi- 
cal Phasnomena .... 

Bill on account of Ane- 
mometrical Observa- 
tions 



2 5 
8 1 




10 



. 13 9 
£159 19 G 



Extracts from Resolutions of the General Committee, 

Committees and individuals, to whom grants of money for scientific pur- 
poses have been entrusted, are required to present to each following meeting 
of the Association a Report of the progress which has been made ; with a 
statement of the sums which have been expended, and the balance which 
remains disjiosable on each grant. 

Grants of pecuniary aid for scientific purposes from the funds of the As- 
sociation expire at the ensuing meeting, unless it shall appear by a Report 
that the Recommendations have been acted on, or a continuation of them be 
ordered by the General Committee. 

In each Committee, the Member first named is the person entitled to call 
on the Treasurer, John Taylor, Esq., 6 Queen Street Place, Upper Thames 
Street, London, for such portion of the sum granted as may from time to 
time be required. 

In grants of money to Committees, the Association does not contemplate 
the payment of personal expenses to the Members. 

In all cases where additional grants of money are made for the continua- 
tion of Researches at the cost of the Association, the sum named shall be 
deemed to include, as a part of the amount, the specified balance which may 
remain unpaid on the former grant for the same object. 



i 



GENERAL STATEMENT. XXVU 

General Meetings (in the Town Hall). 

On Wednesday, September ]2tli, at 8 p.m., the late President, The 
Marquis of Northampton, V.P.R.S., resigned his Office to the Rev. T. R. 
Robinson, D.D., M.R.I. A., who took the Chair at the General Meeting, and 
delivered an Address, for which see p. xxix. 

On Thursday, September 13th, the power of Mr. Gassiot's Battery in ex- 
citing Light and Heat was exhibited, and Dr. Faraday added some explana- 
tion of the Phaenomena. 

On Monday, September 17th, the Rev. Prof. Willis, M.A., F.R.S., gave a 
Discourse and exhibited Working Models, to illustrate the result of some 
recent Experiments on the Transit of different Weights with varying Velo- 
cities on Railways. 

On Wednesday, September 19th, the concluding General Meeting of the 
Association was held, when the Proceedings of the General Committee, and 
the grants of money for scientific purposes were explained to the Members. 

The Meeting was then adjourned to Edinburgh in August 1850*. 
* The Meeting is appointed to take place on Wednesday, 31st July. 



ADDRESS 

BY 

The Rev. THOMAS ROMNEY ROBINSON, D.D., 
M.RJ.A., F.R.A.S. 



Gentlemen, — If 1 thought only of myself, the embarrassment which in 
taking the place to which you have called me I feel, would be much increased 
by the way in which my predecessor has spoken of me. Hitherto it has 
been filled by men illustrious in the senate or the field, heads of the societies 
which are the centres of our scientific life, and lodestars of the great insti- 
tutions which have been through many ages the guides of our nation in the 
progress of intellectual cultivation. Against such men, if I weigh myself, I 
know how much I shall be found wanting. But I trust I may be permitted 
to regard myself as the type of a humbler but not useless class, for whom 
this Association was especially devised, and whom it enables to add their 
tribute to swell the general store. For it is not like the forbidden ground 
of romance, a region where heroes only can tread ; it is not a mere instru- 
ment for collecting into a focus the light of the suns of the intellectual sky. 
It is rather like those machines which unite the power of many ; singly weak, 
but achieving by the union works which would overtask the strength of the 
mightiest individual. In one thing only I will venture to take to myself as 
not unmerited, the praise of Lord Northampton. In zeal for the welfare of 
this Association, in intense interest for the accomplishment of its objects I 
yield to none ; and if these may suffice, I hope I shall not be found unworthy 
of the trust you repose in me. 

Yet, it is no common responsibility with which you have charged me ; for 
this Association is one of the great powers which the altering phases of the 
world have called into action. But a few years since it could not have 
existed ; and even now some persons are found imable to appreciate its 



XXX REPORT — 1849. 

results or understand its purpose. In fact, as the invention of a new machine 
or process of manufacture is evidence that the old is becoming inadequate to 
meet the demand which it formerly satisfied; so the feelings which have so 
successfully called into being our Association here, and similar institutions 
abroad, maybe regarded as a proof that the existing agencies fo r the develop- 
ment of scientific knowledge were becoming unequal to their work, and that 
some higher power must be sought, of energy commensurate to the increasing 
pressure. Such a power, I think, it is now certain that we afford. It is 
possible that the form of this great experiment may receive some modifica- 
tion ; for example, that it may involve a yet wider application of the mighty 
principle on which it is based, and become a union not only of persons but 
of institutions. But we have established beyond doubt that it is a trial in 
the right direction, — that its principle is the true one, the principle of Asso- 
ciation. It may perhaps seem trivial to attach importance to such an asser- 
tion ; in commercial enterprise, in manufactures, in politics its truth is 
universally confessed ; what then is there new in applying it to science ? 
Nothing, assuredly : in fact science, at least physical science, owes to it almost 
its very existence, and certainly its progress ; and the wonder is that none 
seem to have fully comprehended this before the founders of the British 
Association. Observe, that though physical science is of recent birth, physical 
knowledge has been an object of desire from the very origin of our race. 
Some have followed it for the sake of the powers which it conferred ; and 
some from the high instinct which reveals to a noble mind the beauty and 
majesty of such pursuits. In the first glimmer of history, the astronomy of 
the Assyrian Magi looms through the darkness ; the geometry which might 
have been its champion and guide appears in no feeble development even 
in the fabulous antiquity of India. The sepulchres of Etruria and Egypt, 
the palaces of Nineveh, are giving up to us relics of art that imply in high 
perfection the existence of that practical chemistry which was transmitted to 
us through their Arabian successors. When we look at the marvellous archi- 
tecture of the middle ages, we find a mastery of the principles of equilibrium 
and pressure, that fills the mind capable of appreciating it with delight beyond 
even what its surpassing beauty inspires ; and we know from the writings of 
Roger Bacon and Kircher that many facts of experimental physics were cur- 
rent in the cloister. The elements were in existence, but some power was 
wanting which could combine them into a body and give it life. That power 
was free, open, honest association. Not intellectual energy or acuteness : 
the Greeks possessed that to an extent never perhaps equalled by any other 
people ; but they were made incapable of steady union for any purpose, by 
the strange elements of repulsion which seemed inherent in their nature and 



I 



ADDRESS. XXXI 

split their philosophers into sects, their nation into fragments. Elsewhere 
the separation was still wider ; the priestly casts of old, the conventional 
clergy and masonic societies of more recent times, could not coalesce with 
the rest of the world in the union which I hold to be essential to the growth 
of science. Therefore, however extensive their knowledge (and they knew 
more than is generally supposed) it never ripened into general principles ; 
it even became corrupt in the dull stagnation of the mystery in which it was 
buried, — an instrument of superstition or imposture, a delusion to its pos- 
sessors themselves. Astronomy became astrology,— chemistry, alchemy — 
natural philosophy, magic. Brewster has shown how the concave mirror 
brought up an apparition when it was needed, and Boutigny has revealed how 
the repulsive energies of heat ministered to the iniquity of the ordeal. But 
this period of isolated labour, under which the intellectual domain of our 
race lay so long fallow, closed at last ; and the principle of association re- 
vealed itself, at one of the epochs of that movement which from time to time 
stirs up the region of mind, as those of geology do the earth at the com- 
mencement of some great formation. To borrow from that science an illustra- 
tion, — the reign of reptiles and monsters gave way to higher beings that 
soared in the sky ; the dominion of Aristotle and the schoolmen disappeared 
before the age of Copernicus, Kepler, Galileo, and Bacon. From the fifteenth 
century downwards we find the philosophers of Europe beginning to be 
worthy of that name, lovers of knowledge. Instead of wrapping up their 
discoveries in secrecy, using them as a means of influence over the ignorant, 
or brooding on them as food for haughty self-love; we find them forming a 
brotherhood of knowledge, — eager to communicate their inventions, applying 
to each other for instruction, and even disputing among themselves the 
honour of priority in successful research. If the Florentine astronomer 
still envelopes in cipher his observations of Venus and Saturn, it is lest a 
rival should anticipate what was necessary to perfect his discovery : — while 
the Monk of Oxford hides in a similar veil his knowledge of gunpowder to 
exalt himself in the opinion of the world, yet keep his secret. The step in 
advance was wide, and the onward progress was rapid. It is not merely 
that each discovery, which is thus freely communicated, becomes an imperish* 
able addition to the treasury of human knowledge, but it is also a source of 
others, more numerous as it is more widely diffused,— like a syngenesious 
flower, whose winged seeds would produce little if confined to the neigh- 
bourhood of their parent, but bear a thousand-fold when scattered over the 
land. He who first finds a physical fact or principle often fails to trace it to 
its full extent : pre-occupied by some particular object of research, led by 
special views, he looks at it with reference to them alone, — and were he 



XXXli REPORT — 1849. 

sole labourer in the mine, much of its wealth would be lost : it may be too 
vast to be explored by the power of one mind, or within the limits of one 
life ; or it may require aids and appliances which solitary individuals do not 
possess : to say nothing of what is still more important, — the increase of 
energy which flows from the sympathy and admiration of a multitude. It 
is not too much to say, that the progress of mankind in science during the 
two centuries to which I refer, far exceeded what had been made during the 
fifty-six that preceded them : yet the force which impelled it was only par- 
tially and imperfectly exerted, and it was soon felt to be capable of far wider 
application. In this stage of its action the principle of association had ope- 
rated on only a few mighty spirits whom the sense of kindred pursuits and 
powers linked together ; but from whom their very transcendence kept their 
humbler fellows at a reverential distance. It was necessary that these also 
should be included in its bond : — and the age of Societies began. By con- 
densing into a multitude of local centres the activity which was weakened in 
its diffusion, that privilege of labouring to extend the boundaries of know- 
ledge, which had been the glory of a chosen few, was extended to a multitude ; 
societies devoted to this object arose in different co\mtries, varying in con- 
stitution and form, but all emanating from the same necessity of bringing 
united exertion to bear on what every passing year showed to be among 
the noblest objects of human existence. And in this they were eminently 
successful: — strong in numbers, they were stronger in local concentration; 
their definite and permanent organization was a source of life and power ; and 
the visible results of their activity were manifest to the world. In many in- 
stances they acquired a legal and corporate existence, which gave them a 
hold on general opinion and even on governments ; their pecuniary resources 
and moral weight afforded them the means of researches beyond the reach 
of ordinary inquirers ; and their exclusive character, whether limited by 
election or by appointment, by making it an object of ambition to belong to 
them, gained for their pursuits a popularity which their intrinsic worth might 
not so soon have won. A still more — perhaps their most — important feature 
is the principle of systematic publication, the value of which has gone on 
increasing to the present hour, and cannot be overrated. Their Transactions 
gave to the world not merely casual observations, which might otherwise 
have perished, but elaborate investigations, which probably would never 
have found a publisher in the ordinary course of trade, — perhaps never have 
been undertaken had not this channel been open to their authors. It would 
be foreign to my purpose, even were it possible, to give you an account of 
the philosophical societies which have flourished, not merely in Europe, but 
in some of the most distant regions which her sons have reached as colonists 



ADDRESS. XXXIU 

or conquerors. A tlescription of them would nil volumes,— a record cf 
their proceedings would be the history of scientific progress for the last two 
centuries : — I might say of science itself, for, in fact, they began with Newton, 
and he stands like the sun in Heaven ; all is luminous after he has risen, 
all before darkness or twilight. Yet, while rendering to them the praise 
which their services have so well deserved, we must not forget that as they 
were called into existence to meet a state of things which has passed away, 
so the altered condition of the human mind requires from them now a very 
different class of function from those which they discharged at first ; and that 
circumstances may occur in which they may retard instead of advancing the 
progress of knowledge. That which I referred to as an original element of 
their power is of this number, — their restricted and local character ; their 
very nature requires that they be placed in large towns or cities, and they 
cannot multiply their members beyond narrow limits. This was not injurious 
as long as a single room in a tavern was sufficient to hold all the philosophers 
of the metropolis, or the means of experiment and instruction were scarcely 
accessible out of its precincts. It is far otherwise now, — when we count 
more thousands, and those, too, of higher standard in the ranks of science, 
than units could be reckoned at the beginning of last century, and when every 
day adds to their number. No possible extension of the great societies can 
meet this, even were they disposed to make it, — which I believe they are 
not. On the contrary, there is among them a tendency to limit their ad- 
missions to men of high fame and proved attainments, and thus, in some 
degree, form an Aristocracy of Science, What, then, is to become of the 
rest?— are they to form provincial societies similarly organized? This, it 
seems to me, is but a retrograde step ; a violation of the great principle to 
which we owe our advance, — a breaking up into fragments of the energy 
which it should be the aim of all our efforts to associate into one mighty unity ; 
and however valuable such societies areas auxiliaries, unless it be found pos- 
sible to link them, by some principle of federation, unto our great body, with- 
out interfering with their self-government and independence, I feel that much 
of the good which they are capable of effecting must be lost. Secondly, the 
increasing vastness of the field which we have to cultivate surpasses the 
powers of any single body of labourers. Look, for instance, at the most 
I illustrious of all, the Royal Society. At first, as we see from its Transac- 

I j tions, it was a mere collector of detached facts and observations, and for 

I I them took even a wider range than is attempted by all our Sections ; it 
! I collected too, with but little discrimination :: — in that dawning of information it 
\\ was not always possible to distinguish a pebble from a pearl. It soon,how- 

I ever, became fastidious ; for it reached the point when it became more im- 
184.9. d 



XXXIV REPORT — 1849. 

portant to class and interpret than to collect, and the latter part of its office 
became subordinate to the other. By degrees, as its accumulating duties 
began to surpass its powers, we find dissatisfaction appearing, and complaints 
that particular branches of science are neglected to favour others not so im- 
portant. At last, the necessity of a division of work becomes apparent ; a 
society splits off to devote itself to geology, — another to astronomy, — others 
to various branches of Natural History, — while the parent, like Trembley's 
hydra, is more active and powerful than before this division. That this 
process has increased our knowledge a hundred-fold, will not be disputed 
by any who have watched its progress during the last thirty years ; and yet 
it can scarcely be denied that, besides the chance of exciting hostile feelings 
between rival societies, it is open to another objection. The different 
branches of science cannot well be isolated ; each depends on many others. 
Geology presses into its service not merely its special subject, but also the 
Geometry of Hopkins, the Botany of Lindley, and the Zoography of Owen 
and Agassiz. Astronomy must not only track the unseen with Adams and 
Le Verrier, or fathom the abysses of the sky with Herschel and Rosse, — it 
must also visit the workshops of the machinist with Airy and Struve. And 
so of the rest ; they cannot be disunited : and therefore it is evident that some 
system must be found, which, while it leaves unfettered the whole special 
organization of each Society, shall yet combine their exertions, not merely 
with each other, but also with the great and ever-increasing multitude of 
fellow-labourers beyond their precincts. Therefore it was not merely a 
happy thought of the good and wise men who were the founders of the 
British Association which led to its existence; this, or something equivalent, 
was a necessary result of the expansion of that principle whose course I have 
been tracing, and which must, ere long, have found some other development 
had they not turned it in this direction. It leaves untouched all that was 
previously available, and merely adds what experience had shown to be 
deficient. Thus we do not interfere in any way with any Society ; on the 
contrary, we identify ourselves with them as far as possible. We admit, as 
of right, the members of all chartered Societies that publish Transactions 
throughout our empire ; the officers and councils of philosophical institutions, 
and all their members who are recommended by those councils ; and our 
governing power, or General Committee, is almost entirely derived from the 
same source, — it is chiefly composed of " members who have printed papers 
in the Transactions of any philosophical society, or of delegates from such 
societies or philosophical institutions." We withdraw nothing from their 
Transactions ; our reports are of a totally different character ; on the con- 
trary, we assist them ; for many of the most valuable communications, which 



ADDRESS. XXXV 

those publications contain in latter years, have originated in tlie proceedings 
of our Sections. Yet, though we have so much in common with them, it 
would be a gross error to confound us with them, or to imagine that any 
increase of their activity or any change in their management could supersede 
Our Office. Not the least important part of it refers to persons entirely un- 
connected with them, persons who have struggled after knowledge in dif- 
ficulty and obscurity, whose diffidence would shrink from the distinction 
belonging to such connection, or even who, without any scientific acquire- 
ments, have yet a reverence for them, a perception of their worth. Such 
we can count by thousands ; and every one of them, I am confident, has 
been profited by the influence which we have exerted on his mind. We 
have gone still further, and admitted ladies as Associates ; exciting the 
surprise and perhaps scorn of those who think women fit only for household 
cares or showy accomplishments ; and we have done well ; for without re- 
ferring to Mrs. Somerville, Mrs. Marcet, or others whom I would name 
were they not present, I have myself known some whose proficiency in 
several of our departments might have put many an F.R.S. to shame, who 
were not to be surpassed in all the graces of their sex, and were perfect in 
all the relations of domestic life. Man cannot ascend in the scale of intel- 
lectual power unless woman rises with him. Another advantage which we 
possess above stationary societies is, our mobility ; we can pursue our labours 
wherever much is to be learnt or many are to be taught. From the Uni- 
versities, the seats of abstract science, we have ranged to the mighty emporia 
of GreatBritain, to the treasure-houses of its mineral and melallurgic wealth, 
to the marvellous palaces of its industrial art ; and at every step of our 
progress, even the most highly gifted and richly stored among us have learned 
new facts, seen opening before them new lines of thought, and met new men. 
It is a glorious discipline, the very one which Homer attributes to the wisest 
of his heroes : noWtSv avOpwTro)!/ 'ilev aarea KUi voov eyvu). And let us hope, 
that, in the expressive imagery of the New Atlantis, we also may be " dowry 
men " and " merchants of light ; " that they whose seats become the marts of 
our intellectual commerce may receive in it their share df the illumination 
which we seek ; and that by imparting to them new ideas, by correcting 
error, by opening to them more fully the laws which rule those elemental 
powers that serve them in works of microscopic beauty or giant might — we 
may endow them with gifts which shall both increase the reward of their 
own industry and enterprise, and augment the prosperity and glory of our 
country. 

Our Association has been tried during eighteen years, and with a success 
which has exceeded by far what its most ardent friends had ventured to 

d2 



XXXvi REPORT — 1849. 

anticipate. It would of course be unreasonable to expect that its career 
should be at all times equally brilliant, or that an institution, whose roots 
spread into every part of the realm, and every order of its people, can be 
free from the fluctuations by which their prosperity is ruffled. It must also be 
borne in mind, that if we adhere, as I trust we ever shall do, to our rule of 
assembling wherever we are called by the interests of science, we must oc- 
casionally visit remote and unattractive localities, where the difficulties of 
access, and the want of accommodation will discourage many from attending. 
But yet we can truly assert, that in each of these eighteen years — and 
assuredly this nineteenth will be no exception — it has added largely to our 
knowledge, and in no respect fallen short of the objects contemplated by its 
founders. These were, as stated to the original meeting at York, " to pro- 
mote the intercourse of the cultivators of science with each other, and with 
foreign philosophers ;" "to give a stronger impulse, and more systematic 
direction to scientific inquiry ; " " to obtain a greater degree of national 
attention to the objects of science, and a removal of the disadvantages which 
impede its progress." 

Let me request your attention for a few moments respecting each of these. 
The first of them may perhaps be undervalued by some, or rated merely as 
an intellectual luxury. Even at that low estimate, it is above price ; but it 
is of far higher import. If to visit the field of some high deed — to stand 
before the sepulchre of the illustrious dead — can fill the mind with lofty 
aspirations, and lift it to the noblest emprise, how much more shall it kindle 
in the actual presence of one of those great beings who are raised up by our 
Heavenly Father to be the lights of our race ! Who could stand before 
Bessel without feeling how genius is exalted by industry ! What a lesson of 
truth and decision was written on the brow of Dalton ! But our close inter- 
course with each other is still more precious, from its tendency to check some 
evil elements of our nature. For instance, the bitter disputations and petty 
hostility, which have too often disgraced the records of science, and made its 
followers contemptible. The most irritable man must feel less disposed to 
apply violent language, or attribute unworthy motives to one whom he has 
met in kindly intercourse, and whose character he has appreciated, than 
when he encounters a perfect stranger in the arena of the press ; or if lie 
have offended, how many opportunities of atonement and reconciliation are 
offered by a reunion like this ! Accordingly, this fault has nearly disap- 
peared ; and when traces of it occur, it is only in persons who have not 
fully entered into the spirit of our Association. Nor is it less powerful 
to avert a still greater danger — the greatest, in fact, which besets our pur- 
suits — that of self-esteem. The true philosopher does not incur it : he 



I 



ADDRESS. XXXVll 

knows too well the proportion between his ignorance and his knowledge ; 
but if there be any who, from being the wonder of a limited circle, or from 
exaggerating the difficulty of his own attainments, is disposed to exalt him- 
self above his peers, let him visit us, and I will answer for his cure. There 
is not a man on earth who could try the experiment without finding supe- 
riors in some of our departments, and scarcely any who would not find an 
equal in that of which he is vain. 

As to our foreign visitors, I need not take the trouble of proving what 
you all feel : the attracting them to our shores — the having the opportunity 
of knowing such men as Arago and CErsted, Ritter, Encke or Struve, Bache 
or Henry — of strengthening by the ties of friendship that brotherhood of 
science, to which I have already referred as of such importance — that alone 
would be worth an Association to obtain it. Even on this, the first night of 
our meeting, we are honoured by several distinguished guests. On another 
occasion 1 shall express to them our acknowledgement of the honour with 
which their presence graces us ; but now shall refer only to one — the Che- 
valier Bunsen — in answer to any who may suppose that an attachment to any 
of the various branches of science, in which he is so highly gifted, unfits a 
man for the most energetic discharge of the active duties of publicJife. 

In the second object — " to give a stronger impulse and more systematic di- 
rection to scientific inquiry " — we have not been less successful. The very 
excitement connected with our meetings, is itself such an impulse, and a most 
powerful one. Those of our members who have long been known as the 
chief ornaments of our great philosophical societies — devoted to science, and 
rich in its triumphs — feel it as fully now as when first they joined us. At 
each new occurrence they seem to find a renovation of enthusiasm — a flow of 
hope, an increase of resolution among us — which send them with fresh 
strength to resume their labours ; and will be present to them in the hours 
of despondency and gloom, which at times cloud even the firmest spirits, like a 
beam of light. Nor is our spell less potent on those yet untried in the race, 
who come forward to communicate the first fruits of their research — the truth 
which has rewarded their solitary toil. To such, the approbation, the kind 
advice, the affectionate warning of their more renowned companions, is like 
a horoscope that stamps the future course of life ; more powerful even than 
the applause of the multitude, who rejoice at the success of one unknown, and 
are encouraged by it to similar exertion. But still more precious is the ex- 
citement of plunging into this mighty flow of intellect, to one whose lot is like 
mine, cast remote from the resorts of science — with few or none near him to 
understand or value his pursuits ; nothing but his own fixity of resolve to 
disperse the listlessness which thus gathers on the mind and clogs its wing. 



xxxviii REPORT— 1849. 

To him you are as an oasis to the travellers in the Desert, whose palms and 
fountains make him forget the waste which he has left, and store him for 
another journey with the means of life. But we not only give this impulse, 
we also guide it ; and by guiding it, sustain and increase its strength, as well 
as by removing the difficulties which resist it. A small part of what we 
have thus accomplished you find in the volumes which we have published ; 
the most important, as I already stated, is to be found in the Transactions of 
various Societies or in separate works. Let me select a few instances, for 
rapid notice, as time will fail for more. To begin with the science to which 
I myself am specially devoted — Astronomy : it has been above all others 
patronized by nations and individuals ; in our own country a Society of high 
fame and influence has been established for its advancement ; and yet it has 
remained for us to render it services of no common order, which I may be 
permitted to explain in some detail. In it, as in many other physical sciences, 
the observation of facts is merely the crude ore, which must be sorted, and 
sifted and passed through the furnace to make it yield the metal which we 
seek. The mere task of making the observations is generally a pleasure ; 
but it is far otherwise with the subsequent process. The arithmetical opera- 
tions whjch it requires, demand much more time and involve much more 
labour ; that, too, rather intellectual, and involving at every step liabilities 
to error. Take a simple instance : you have determined with minute pre- 
cision the apparent place of a star in the sky — if you stop then, you have 
done nothing. The place you have obtained is not the true one : the atmo- 
sphere has bent the line of sight ; while the light travels down your telescope 
you and it have been moving ; and the sky-marks by which you map the star 
are themselves disturbed by various and complicated motions. For all these 
you must allow ; but to do so requires, on j^n average, even in the most im- 
proved method of modern times, the writing of 400 figures and the perfonn- 
ance of 50 arithmetical operations. But the numbers themselves employed 
are the result of other complicated operations ; nearly half are constant for 
the same star, but an equal number have relation to the sun and moon, and 
therefore vary from day to day. Were these also to be calculated, it would 
add an equal amount of work. But even this is insufficient, for we must 
compare what we thus obtain with the results of former astronomers ; and 
this also cannot be done without bringing them together by the same arith- 
metic talisman ; so that were the whole to be performed by the one calcu- 
lator, I have found that, however expert he may be, he must expend an hour 
at least in obtaining each result. Now, from most of this drudgery in the 
case of more than 8000 stars, he is relieved by the Catalogue which the 
Association has given to the world. It contains for each the constants already 



ADDRESS. XXXIX 

noticed ; and gives the prompt and easy means of making the comparison ; 
so easy, that probably before its epocli, 1850, is past, every one of those 
places will have been verified in the sky. Such an undertaking could have 
been effected only by such a power as ours, which could at once engage the 
services of such men as Baily, Herschel, Stratford and their fellow-laboui-ers, 
and devote to the inferior part of the work an expenditure exceeding 2000/. 
In fact, had we done nothing else, I say fearlessly that this work alone would 
have secured us an enduring claim on the gratitude of science. Let me here 
remark, that there are many other departments in which we could render 
most important service by the mere collection of the Constants that belong 
to them ; as we have done in this case and in that of terrestrial magnetism. 
Constants are the framework of knowledge, the concentration of power ; 
they belong peculiarly to our domain, and were marked out as such long 
since ; but though unfortunately this work was not executed by that power- 
ful mind to whom we entrusted it, I hope the subject will not be forgotten, 
I might tell you of the theory of the tides, which Laplace might well style 
•' the most thorny of problems," but of the greatest interest to a nation 

" Whose march is o'er the mountain wave, 
Whose home is on the deep." 

I might tell you of light thrown on it by observations obtained by our influ- 
ence, reduced at our expense, and unravelled by one worthy of going be- 
yond the steps of Newton and Bernouilli. To the same philosopher we owe 
the execution of another important task, — the determination of the plane which 
marks the level of the sea unvarying with the changes of the tide ; a precious 
gift, as but for it in a few years the absolute levels of our great national sur- 
veys would have become a delusion. In Ireland, for example, they referred 
to the low'water of spring-tides ; a mark which could not be recovered, as 
it varies both with time and place. I know not whether this has been yet 
corrected, but I trust it soon will, as Airy's observations afford the data. It 
would be tedious to tell you all of this kind that we have effected ; and I 
leave the subject, with a reference to one more example, — the investigation 
of the motion and nature of waves which we owe to Mr. Scott Russell. 
These lead by an unexpected line to one far more interesting in a practical 
view, the resistance and the form of ships. On this subject it appears that 
valuable information has been collected for us ; and it cannot but be matter 
of regret that materials obtained at so great an expenditure of money (more 
than 1000/.), of labour and thought should remain unavailable, especially 
considering the present imperfect condition of naval architecture in reference 
to science. In many instances we have aided inquiries of inestimable value, 



xl REPORT — 1849. 

though we (lid not originate them: — as the Fossil Icththyology of Agassiz, 
and those of Owen on Fossil Reptiles and Mammalia, which perhaps but for 
us would never have been completed ; and in fine I may mention as an ap- 
proximative measure of the impulse which we have given to science, that we 
have expended in this way 15,000/. Observe, too, that to this must be 
added whatever is the pecuniary value of the labours of those members of 
tiie Association who have given us their services. That all is gratuitous ; 
and if you consider who many of them are, you will find it not easy to assign 
its price. But I regard as even more conducive to the advancement of 
science, another part of our labours, peculiarly our own, — I mean the reports 
which place before us the actual boundaries of our knowledge. Much intel- 
lectual energy is wasted in inventing what is already known ; much spent on 
objects comparatively unimportant for want of a due estimate of their worth, 
many walks untrodden because it is supposed they have been sufficiently ex- 
plored. For all this a remedy is found in those admirable surveys, so many 
of which are found in our volumes ; they are as it were a " taking stock " of 
our intellectual wealth, and tell us how much of it is real, bow much doubt- 
ful, how much wanting. Whether we consider those which embrace a whole 
science, as those of Airy on astronomy or Forbes on meteorology, — or those 
which include some one of its divisions, as those of Sabine on terrestrial 
magnetism, Lloyd on physical optics, Rennie on hydraulics, those by the 
Dean of Ely and his compeers on parts of mathematical analysis, or those of 
Owen and his fellow-labourers in natural history, with a multitude of others, 
— it is scarcely possible to over-estimate their worth. You find there con- 
densed into a few pages the essence of many volumes ; the chaos of clashing 
statements and conflicting opinions reduced to harmony and order ; truth 
winnowed from error, facts from conjecture. They place within the reach 
of the most secluded student, a treasure of certain information which it 
would be hard for him to obtain, even had he access to the libraries and in- 
stitutions of the metropolis ; and even to the mind that is best stored they 
save time,— and time is power. Such reports we shall I trust continue to 
receive in increasing numbers ; and as long as we do, we prosper, for they 
are the surest index, though not the most showy, of our usefulness. 

I have left myself but little space to consider how far we have fulfilled the 
third of our objects — " to obtain a greater degree of national attention to the 
objects of science." Most assuredly it was needful ; for nowhere in the ci- 
vilized world is less honour paid by a nation to science, though nowhere is 
national prosperity more connected with its progress, nowhere are heavier 
penalties paid for its neglect. I do not now refer to the remarkable fact that in 
Britain alone, men whose scientific fame fills all Europe were seldom thought 



ADDRESS. Xli 

worthy of any honorary distinction by their government. As it relates to 
themselves, this is of no importance ; but it is of deep concern to the honour 
of this country. The true votary of science loves it for itself: in its posses- 
sion he has a higher honour, a nobler decoration than tnan can give. He 
does not require to be bribed to follow it by titles or ribbons, — the baits for 
meaner spirits, the lure to lower achievements. But he knows that though 
he despises such gauds, those who bestow them hold them precious ; and 
they serve him as a scale, by which he finds that great men once placed a 
Herschel or a Brewster nearly on a level with a third-rate soldier, or the an- 
nual magistrate of some town that might be honoured with a royal visit. 
Nor do I refer to the miserable oeconomy which permitted such men as Ivory 
and Dalton (to speak only of the dead) to waste, in the drudgery of earning 
a precarious subsistence, the years, the powers, the hopes which could have 
borne light into the remotest and darkest recesses of the realms of inquiry ; 
though it does contrast painfully with the munificent provision which repub- 
lican France, and despotic Russia, heap on such men when they can find them. 
Both these spring from the same root, — the gross ignorance in this depart- 
ment of intellect, which up to the beginning of this Association, and long after- 
wards, prevailed in the land. The industrial classes of our countrymen were 
wont to rely in their pursuits on the unenlightened dexterity and empirical 
success which resulted from experience, and to scoff at the idea of learning 
anything useful from a mere theorist ; those, whom wealth and independence 
permitted to choose, seldom sought employment or pleasure in this unfashion- 
able region, their education, though the best then current, having given them 
very little cognizance of what it might contain. And to ascend still higher, 
even to the executive and legislative bodies, they "cared still less for science ;" 
the tension of political life engrossed all their faculties : they disliked philo- 
sophers as meddlers, or despised them as dreamers. The head of a great 
military department once said that he hated scientific officers ! Any one of 
his engineers might have told him that more money had been wasted, and 
lives lost in that department, from sheer ignorance of science, than any one 
could think of without shame and sorrow. The question which I know to 
have been asked by another in " high places," though milder in expression, 
was not less scornful — " Of what use is science ? " He who asked it ought 
to have known better. Whatever tends to raise man above low and sensual 
pursuits — whatever to lead him from the partial and present to the general 
and the future — whatever to exalt in his mind the dominion of order and the 
supremacy of truth, — that must be useful to the individual, useful to the na- 
tion. Even had he been incapable of rising above the gross measure of pe- 
cuniary value, he ought to have been able to give a mighty answer to his own 



Jtlii REPORT — 1849. 

inquiry. There is not a single element of our commercial prosperity in which 
the vivifying power of science might not be felt, in which the loss arising from 
want of that certainty of action which mere unenlightened practice can never 
•attain, does not readi an amount which, if stated in figures, would astound the 
most thoughtless. For instance, the causes which in our great cities hasten 
the death and debase and embitter the life of so many, have at last been 
forced by chemists and physiologists on the notice of the public, Look at 
Dr. Smith's report on tlie air and water of towns, in this volume ; and when 
we think that the victims of the deadly influences which are there revealed 
are chiefly found among the people whose industry is the foundation of our 
greatness, — that every year cut off from the life of each of these is so much 
subtracted from, national wealth, — even were all moral sense or religious 
feeling dead in us, we must confess that the knowledge which is caipable of 
^verting them " is of use." And the ships that bear the treasures produced 
by this industry through the world are lost to a fearful amount — nearly three 
daily. What are they worth — ship, cargo, men? and most of them perish 
from want of nautical science or from unscientific construction. How many 
men have been ruined by searching for minerals, when the merest smattering 
of geology would have dispelled their delusion ! On the other hand, the 
agricultural produce of our islands might be doubled by a more perfect ap- 
plication of the principles of botany and chemistry. The manufacture of iron 
has been augmented sixfold by the use of the puddling furnace and the hot" 
blast — both gifts of theory. How gigantic a result is this, without reference 
to the increase in the thousand arts of which this immense supply of that 
most precious of metals is the exponent! The splendid machinery in which 
we excel the world owes its present perfection to mechanicians who are con- 
spicuous in Qur Sections, to impulses given by philosophers like Willis or 
Babbage. Nay, the steam-engine itself, your immortal townsman's great 
conquest, — that earthly fate to which now seems to be committed the weaving 
of the world's destiny,— that itself was a pure induction of science: — and 
beyond that I need not go. But we live in better times ; for no statesman 
now would be so imprudent as to ask such a question, even were there any 
so unfortunate as to think it, which I trust there are not. And this change 
we, the British Association, have in no small degree helped to produce. We 
have carried far and wide through the land the light which before beamed 
only from a few scattered points ; if our meteor-like presence be short it is 
also bright ; and as the meteor is remembered when the stationary lamp is 
unheeded, so I trust that of the tens of thousands who have felt our influence, 
few will forget the impression which it made on them, and fewer fail to feel 
that this impression ennobled and exalted their understanding. It is evident 



i 



ADDRESS. XlUi 

that science now has a far more powerful hold on public opinion than when 
we began our course. No other proof is needed of this than the fact that 
many new branches of it are finding their way into the course of University 
instruction. Without referring to the recent changes in those of this island, 
I rejoice to say that in my own — that of Dublin — within the last year che- 
mistry, thermotics, electro-magnetism, and others, have been made a portion 
of the under-graduatQ course ; while one of our own valued members has 
introduced into primary schools a manual of zoology, of which the spirit is 
as good !(s the substance is attractive. But there is another evidence, not 
less satisfactory in reference to this our third object, and I name it with 
pleasure, — the prompt and liberal attention which our government now pays 
to the requests of the Association. It is true that we have never applied to 
it except for matters of paramount importance and unquestionable useful- 
ness ; but in times past it would have been no easy matter to force a con- 
viction of this on the guardians of the Treasury ; and we may therefore feel 
assured, not only that they personally take an interest in what we bring be- 
fore themi but also that the whole nation aympathisses with us ; for some of 
these concessions are of no ordinary magnitude. The completion of the 
Ordnance survey of Scotland — the enlarging the scale of part, perhaps all, 
of that of England— and the adding lines of level to that of Ireland after it 
was apparently completed — are very formidable items in a budget. At our 
demands, the observatories from which such splendid additions have been 
made to our knowledge of magnetism and meteorology have been establislied 
far and wide throughout our dominions : — a precious gift, not only for itself, 
but for what it has produced. The example was followed, on their usual 
princely scale, at four stations by the East India Company (always, be it said, 
munificent patrons of science), and still more extensively by Russia-^with 
what success must be fresh in the memory of those who were present at the 
Magnetic Congress. We obtained the antarctic expedition of Ross, so fertile 
in its geographic fruit— so invaluable for the wide extension which it gave to 
the domain of terrestrial magnetism. We procured the expenditure of large 
sums for the reduQtipn of the Greenwich lunar observations, and for publish- 
ing the Catalogues of Lacaille and Lalande, — and much more which I need 
not recite. Yet — and we well may reckon it a sign of progress — not a single 
voice has been raised in opposition to these grants. It seems as if our 
country recognized in us its scientific representatives-^ — as if we were like the 
Saxon prototype of its great council : its Witena-Gemot — its assembly of 
the Wise. 

And may we deserve that name ; for let me remind you that science is not 
necessarily wisdom* To know, is not the sole nor even the highest office of 



Xliv REPORT — 1849. 

the intellect ; and it loses all its glory unless it act in furtherance of the great 
end of man's life. That end is, as both reason and revelation unite in telling 
us, to acquire the feelings and habits that will lead us to love and seek what 
is good in all its forms, and guide us by following its traces to the first Great 
Cause of all, where only we find it pure and unclouded. If science be culti- 
vated in congruity with this, it is the most precious possession we can have — 
the most divine endowment. But if it be perverted to minister to any wicked 
or icrnoble purpose — if it even be permitted to take too absolute a hold of the 
mind, or overshadow that which should be paramount over all, the perception 
of ri^ht, the sense of Duty — if it does not increase in us the consciousness 
of an Almighty and All-beneficent presence, — it lowers instead of raising us 
in the great scale of existence. This, however, it can never do but by our 
fault. All its tendencies are heavenward ; every new fact which it reveals 
is a ray from the origin of light, which leads us to its source. If any think 
otherwise, their knowledge is imperfect, or their understanding warped, or 
darkened by their passions. The book of nature is, like that of revelation, 
written by God, and therefore cannot contradict it ; both we are unable to read 
through all their extent, and therefore should neither wonder nor be alarmed 
if at times we miss the pages which reconcile any seeming inconsistence. In 
both, too, we may fail to interpret rightly that which is recorded ; but be as- 
sured, if we search them in quest of truth alone, each will bear witness to the 
other, — and physical knowledge, instead of being hostile to religion, will be 
found its most powerful ally, its most useful servant. Many, I know, think 
otherwise ; and because attempts have occasionally been made to draw from 
astronomy, from geology, from the modes of the growth and formation of 
animals and plants, arguments against the divine origin of the sacred Scrip- 
ture, or even to substitute for the creative will of an intelligent first cause the 
blind and casual evolution of some agency of a material system, they would 
reject their study as fraught with danger. In this I must express my deep 
conviction that they do injury to that very cause which they think they are 
serving. 

Time will not let me touch further on the cavils and errors in question ; 
and besides they have been often fully answered. I will only say, that I am 
here surrounded by many, matchless in the sciences which are supposed so 
dangerous, and not less conspicuous for truth and piety. If they find no 
discord between faith and knowledge, why should you or any suppose it to 
exist ? On the contrary, they cannot be well separated. We must know 
that God is, before we can confess Him ; we must know that He is wise and 
powerful before we can trust in Him, — that He is good- before we can love 
Him. All these attributes, the study of His works had made known before 



ADDRESS. Hv 

He gave that more perfect knowledge of himself with which we are blessed. 
Among the Semitic tribes his names betoken exalted nature and resistless 
power ; among the Hellenic races ihey denote his wisdom ; but that which 
we inherit from our northern ancestors denotes his goodness. All these the 
more perfect researches of modern science bring out in ever.increasing splen- 
dour ; and I cannot conceive anything that more effectually brings home to 
the mind the absolute omnipresence of the Deity than high physical know- 
ledge. I fear I have too long trespassed on your patience, yet let me point 
out to you a few examples. What can fill us with an overwhelming sense of 
His infinite wisdom like the telescope ? As you sound with it the fathomless 
abyss of stars, till all measure of distances seems to fail and imagination alone 
gauges the distance ; yet even there as here is the same divine harmony of 
forces, the same perfect conservation of systems, which the being able to trace 
in the pages of Newton or Laplace makes us feel as if we were more than 
men. If it is such a triumph of intellect to trace this law of the universe, 
how transcendent must that Greatest over all be, in which it and many like 
it, have their existence ! That instrument tells us that the globe which we 
inhabit is but a speck, the existence of which cannot be perceived beyond our 
system. Can we then hope that in this immensity of worlds we shall not be 
overlooked? The microscope will answer. If the telescope lead to one verge 
of infinity, t^ brings us to ihe other ; and shows us that down in the very twi- 
light of visibility the living points which it discloses are fashioned with the 
most finished perfection, — that the most marvellous contrivances minister to 
their preservation and their enjoyment, — that as nothing is too vast for the 
Creator's control, so nothing is too minute or trifling for His care. At every 
turn the philosopher meets facts which show that man's Creator is also his 
Father, — things which seem to contain a special provision for his use and his 
happiness : but I will take only two, from their special relation to this very 
district. Is it possible to consider the properties which distinguish iron from 
other metals without a conviction that those qualities were given to it that it 
might be useful to man, whatever other purposes might be answered by them ? 
That it should be ductile and plastic while influenced by heat, capable of being 
welded, and yet by a slight chemical change capable of adamantine hardness, 
— and that the metal which alone possesses properties so precious should be 
the most abundant of all, — must seem, as it is, a miracle of bounty. And 
not less marvellous is the prescient kindness which stored up in your coal- 
fields the exuberant vegetation of the ancient world, under circumstances 
which preserved this precious magazine of wealth and power, not merely till 
He had placed on earth beings who would use it, but even to a late period 
of their existence, lest the element that was to develope to the utmost their 



Xlvi REPORT — 1849. 

civilization and energy might be wasted or abused. But I must conclude 
with this summary of all which I. would wish to impress on your minds — 
that the more we know His works the nearer we are to Him. Such know- 
ledge pleases Him; it is bright and holy, it is our purest happiness here, and 
will assuredly follow us into another life if rightly sought in this. May He 
guide us in its pursuit ; and in particular, may this meeting which I have 
attempted to open in His name, be successful and prosperous, so that in 
future years they who follow me in this high office may refer to it as one to 
be remembered with unmixed satisfaction. 



I 



REPORTS 



ON 



THE STATE OF SCIENCE. 



A Catalogue of Observations of Luminous Meteors; continued from 
the Reports of the British Association for 1848. By the Rev. 
Baden Powell, M,A., F.R.S. ^c, Savilian Professor of Geo- 
metry, Oxford. 

In endeavouring to carry on the design of collecting in one record the obser- 
vations of Luminous Meteors made in all parts of the world, commenced last 
year under the auspices of the British Association, I have received valuable 
aid from the communications with which I have been favoured by various cor- 
respondents ; among whom I cannot omit to acknoM'ledge my most particular 
obligations to Dr. Buist of Bombay, and, for by far the most extensive series 
of observations (both of his own, and collected from several friends), to 
E. J. Lowe, Esq. I have also occasionally derived other important materials 
from several journals. The following Catalogue, besides observations of a 
date subsequent to the conclusion of my former list, fills up some of its de- 
fects by observations contemporaneous with it, and others belonging to former 
years. I have also been enabled to prefix some notice of still earlier phaeno- 
mena of this class. 

In ordinary cases the original statement has been entered in the Catalogue 
with only slight verbal abridgements : but where there is a description of any 
physical appearance I have alw'ays retained the words of the author ; and in 
cases where there seemed to be any peculiarity, the original document at 
length is given in the Appendix. The time is usually no more than the com- 
mon clock time, unless otherwise stated : but in all Mr. Lowe's observations 
it is Greenwich Mean Time. 

A continuation of communications is earnestly requested, addressed to the 
author at Oxford. 



I. A valuable collection of records of Luminous Meteors and Star-showers 
from ancient chronicles, extending from a.d. 338 to 1223, is given by M. 
Chasles in the Comptes Rendus, March 15, 1841. 

On a comparison of the results, M. Chasles remarks the absence of anj' 
periodical showers in August or November. But in the earlier years there 
appears such a periodicity in February, and afterwards in March and April. 
He conjectures that the meteoric matter may form a ring, the plane of which 
changes continually ; and thus the same matter may in later years have caused 
the occurrence of the November meteors. 

1849. B 



2 REPORT — 1849. 

II. For the following list of Meteorites, which have fallen in Hungary, I am 
indebted to W. W. Smyth, Esq., M.A., Mining Geologist to the Geological 
Survey. 

1559. The first accurately known as to date : 5 pieces of iron of the size 

of a human head, fell near Miskolez. 
1618. Three stones, each of a cwt., fell in Murakoz, of which the Turkish 

Pasha supplied a full account. 
1642. Between Ofeu and Gran. 
1676. In Dalmatia. 
1692. Near Temeswar. 
1717 & 1740. On the Danube. 
1751. In Croatia a meteorite fell in the form of fiery lumps, and sank 18 

feet in the earth. 
1808, 1812, 1814. In the Saros country. The last was a stone of 133 lbs. 

weight. 
1808. May. A meteorite fell at Stannern, near Blansko, in Moravia. (See 

Appendix, No. 1.) 
1816. Near Pest, and in Nagy Banya. 
1818. Near Mehadia, a meteor by which the whole neighbourhood was 

illuminated for 5 minutes. 
1820. In Ocdenburg. 
1833. In the Presburg Aue. 

1833. Nov. 25. At the same place a brilliant meteor with an explosion: 

three meteoric stones found. (See Appendix, No. 1.) 

1834. In Zala. 

1836. At the Plattensee. 

1837 & 1842. Phaenomena of the kind were seen. 



III. Observations of Meteors previous to the Date of the former 
Catalogue. 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1830. 
Feb. 15 


7h io°> P.M. A bright meteor = 
full moon, moved rapidly 
from N.E. to S.W., after 
about 4 seconds vanished, 
leaving a train of light 
slightly wavering. 


Near Birming- 
ham. 


Dr. Hopkins... 


Appendix, No. 15. 


1838. 


7'' 30"' P.M. A bright meteor = 
full moon, btii of singularly 
contorted form — perfectly 
stationary for about 20 
minutes, then gradually dis- 
appeared. 


Palamcottab, 
South India 


Rev. G. Pettit.. 


Appendix, No. 16. 



I 



A CATALOGUE OP OBSERVATIONS OP LUMINOUS METEORS. 3 



Observations of Meteors in 1843 and 184'4, communicated hy Dr. Buist. 
See Appendix, No. 3. 

From the unpublished Reports of the Colaba Magnetic Observatory. 



Date. 


Bombay 
Mean Time. 


Description. 


Magnitude. 


Duration, 


1843. 


h m 






sec. 


Nov. 8 


3 42 a.m.... 


A meteor passed from S.W. to S. 






9 


11 39 p.m.... 


Do. from a little above the horizon to- 
wards W, 






14 


52 a.m.... 

1 37 a.m.... 

3 28 a.m.... 

8 35 p.m.... 
8 41 p.m.... 
8 46 p.m.... 

8 49 p.m.... 
11 27 p.m.... 
11 55 p.m.... 


Do, northward from below the zenith 
Do. from little above the S. horizon to 

the S. horizon. 
Do. by the zenith from N. to S. 
Do. far below zenith from the N. to S. 

horizon. 
Do. a little below zenith. 
Do. another in the same direction. 
Do. another a little below zenith in the 

N.W. 
Do. another in the zenith. 
Do. a little below zenith towards S.W. 
Do. a little above the horizon in the W. 






15.... 


1 45 30'a.m 
1 57 a.m... 

10 22 p.m... 

10 26 p.m.... 

10 33 p.m.... 
10 45 p.m.... 
10 55 p.m.... 


Do. from a Argus to the S.W. 

Do. from Sirius to the E. 

Do. from far below zenith to the S. 

Do, from a little above the horizon to 

the E. 
Do, from a little above the horizon to 

theE. 
Do, from a little above the horizon to 

theS. 
Do, from a little above the horizon to 

the N. 






16.... 


24 a.m.... 
6 37 a.m.... 

10 58 p.m.... 

11 22 p.m.... 

11 37 p.m.... 
11 52 p.m.... 


Do. from Orion towards the E, 

Do, from a little above the horizon to 
N.E, 

Do, from a little above the horizon to- 
wards E, 

Do, from a little above the horizon to- 
wards N, 

Do. from a little below zenith to S.E. 

Do. from far below zenith to S. 






17 


8 24 p.m.... 
10 7 p.m.... 


Do. in the N, 

Do, from a little below zenith towards S, 






20 


8 33 p.m.... 
10 3 p.m.... 


Do. from N.E. to N. 
Do. from S. to S.E. 






1844. 










Nov. 2 


2 49 a.m..,. 


Brilliant meteor from about 15° above 
the S, horizon to it. 


1 


4 


3 


3 52 a.m.... 

4 41 a.m.... 


Small do. to the western horizon from 

a little above it. 
Do. by Ursa Major towards eastern 

horizon. 


5 




4 


2 47 a.m.,.. 


Do. westward from the zenith 


6 






3 39 a.m.... 


Meteor passed to the S. horizon fi-om a 
little above it. 


2 






3 45 a.m.... 


Brilliant do. to the western horizon from 


1 








a little above it. 





b2 



REPORT — 1849. 



Date. 



1844. 
Nov. 4 . 



Bombay 
Mean Time. 



Description. 



10, 



h m 

7 46 p.m... 

9 35 p.m... 

7 56 p.m... 
2 20 a.m.... 
2 32 a.m.. 
2 57 a.m.... 

2 57 30'a.m. 

3 45 a.m.... 

4 46 a.m.... 

10 49 p.m.... 
10 57 p.m.... 



11 22 p.m... 

2 56 a.m... 
4 22 a.m... 
4 24 a.m... 

11 41 p.m... 
11 55 p.m... 

23 a.m... 

1 27 a.m... 

1 40 a.m... 

2 22 a.m... 
2 41 a.m... 

2 47 a.m... 

3 27 a.m.. 
3 42 a.m.. 
3 47 a.m.. 

3 59 a.m.. 

4 46 a.m.. 
7 40 p.m.. 

7 57 p.m.. 

8 27 p.m.. 

8 38 p.m.. 

9 27 p.m.. 
9 32 p.m.. 
1 20 a.ra.. 



Meteor passed in a western direction 

from above the northern horizon. 
Do. in the N.E. towards the N.E. hori- 



Magnitude. 



Duration. 



Do. from the zenith towards the S 

Do. southward 

Brilliant do. northward, from the zenith 

Small do. passed westward 

Meteor south wai-d from the zenith 

Very brilliant do. rapidly from the E. of 

zenith to the S. 
Meteor eastward from a little above 

the N. horizon. 
Do. iu the north, passed towards the N. 

horizon. 
Do. in the N.E. of the 3rd magnitude. 
Two others in the constellation Orion, 
one of the 5th, the other of the 3rd 
magnitude; the latter a shooting 
one. 

Do. in the zenith of the 6tli magnitude ; 
another near Gemini, in the N.E. at 
111" 51" P.M., of the 3rd magnitude. 
Small do. from the Pleiades to the N.. 

Meteor from the zenith to the S 

Brilliant do. westward from a little 
above the Pole-star. 

Meteor iuthe N.E 

Do. in the N.E 

Do. northward from the zenith .... 
Do. to the southern horizon from a little 

above it. 
Small do. to the W. horizon from a 

little above it. 
Brilliant do. from the west of « Orionis 

to S.W. 

Three meteors passed from the north of 
the zenith, one to the west, one to the 
south, and one to the north. 
Four or five meteors were observed 

going to and fro in the zenith. 
Meteor rapidly from far below the zenith 

to N.E. 
Do. followed by another smaller one, 

eastward from zenith. 
Very brilliant do. from Ursa Major to 

the north. 
Meteor from a little above the W. 
horizon to N.V\^ 

Do. from above the horizon to west 

Do. from a little below the zenith to S 
Do. from a little above the North Pole 
star towards the horizon. 

Very small do. fromN. towards W 

Small do. from a little below zenith to 

wards N. 
Meteor from the zenith towards W. .. 

Do. from N. to N.E 

Do. eastward from the zenith 



1 &6 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 5 



Date. 



1844. 
Nov. 10. 



Bombay 
Mean Time. 



h m 

1 25 a.ra... 

1 39 a.m.., 

1 47 a.m.. 

2 50 a.m.. 

2 57 a.m.. 

3 26 a.m.. 

3 39 a.m.. 

3 45 a.m.. 
3 46 a.m.. 

3 55 a.m.. 

4 42 a.m.. 
7 50 p.m.. 



Description. 



Magnitude. 



12. 



11 25 p.m.. 
11 36 p.m., 
11 53 p.m. 

1 37 a.m. 



1 42 a.m.., 

1 51 a.m.. 

2 3 a.m.. 
2 37 a.m.. 

2 47 a.m.. 

2 48 a.m.. 

3 20 a.m.. 

3 38 a.m.. 

4 34 a.m.. 
7 52 p.m. 

10 44 p.m. 

10 56 p.m. 

11 29 p.m. 
1 27 a.m. 



Small meteor westward from a little be- 
low the zenith. 

Do. N.E. from Ursa Major 

Meteor by the E. of Ursa Major to 

E. horizon. 
Do. from a little below the S. horizon to 

theE. 
Brilliant do. E. from Sirius, to Milky 

Way. 
Do. by the E. of Ursa Major to the N.E. 

horizon. 
Meteor rapidly by the W. of Pole- 
star to the N. 
Small do. westward from the zenith 

Do. towards the N 

Meteor near the zenith, and was lost 

near Ursa Major. ] 

Do. from below the zenith, passed to-i 

wards the northern horizon. 
A small meteor appeared in the north, 
very near the zenith, where it was 
lost. 
Two meteors flashed along the zenith.. 
Meteor in the east, passed southward.. 
Do. in the N.E., passed towards the 

horizon. 
Two small meteors were observed in the 
Milky Way, one passing to the E. the 
other to "the W. 
Meteor near a Orionis, passed eastward 

from the Milky Way. 
Brilliant do. from a little above the 
Pole-star to the N. horizon. I 

Small do. eastward from a little below 

the zenith. 
Three small meteors, at the interval of 
minutes, were seen in the Milky Way, 
E. of zenith. 
Meteor passed rapidly from the E. of 

the zenith to it. 
Brilliant do. from Aldebaran towards 

the W. 
Do. northward from r\ Ursa Major 
Meteor northward from a little above 

the Pole-star. 
Do. from the zenith towards the E.,ana 
another from below the zenith to- 
wards the eastern horizon. I 
Two do. successively, one from above 
the horizon westward, and another 
towards the S. 
Small do. in the N.E. by E., a little be- 
low the zenith. 
Do. in the N.E., a little below the 

zenith. 
Meteor in the N.E., a little below the 

zenith. 
Brilliant do. from Canis Minor to the 
S.W. 



Duration. 



5 &6 
5 
5 



3&4 



REPORT — 1849. 



Bombay 
Mean Time. 



h m 

1 42 a.m.... 

1 57 a.m.... 

2 2 a.m..., 
2 20 a.m.... 

2 20 30'a.m 

2 26 a.m... 

2 37 a.m... 

2 46 a.m... 

2 49 a.m..., 

3 00 a.m... 

3 30 a.m... 

3 45 a.m... 

3 49 a.m... 
3 55 a.m... 

3 59 a.m... 

4 20 a.m... 
7 56 p.m... 

10 53 p.m... 

11 17 p.m... 
22 p.m... 
35 a.m... 

48 a.m... 

55 a.m... 

1 32 a.m... 
1 45 a.m... 



Description. 



50 a.m.. 

00 a.m.. 

25 a.m., 

47 a.m.. 

55 a.m., 

25 a.m., 

33 a.m.. 



3 54 a.m., 



7 55 p.m., 
1 28 a.m., 

1 40 a.m. 

1 57 a.m. 

2 55 a.m., 
2 56 a.m.. 



Magnitude. 



Duration. 



Very brilliant meteor from a little above 

Ursa Major to the W. 
Meteor from Cassiopeia to the W. . . 

Small do. near Cassiopeia 

Brilliant do. from the E. of Ursa Major 

to N.E. 
Smaller one from a little below « Eri- 

dani to the S. horizon. 
Small do. from /3 Arietis to the W. 
Meteor from (8 Cassiopeia to the N. 

Do. westward from a Arietis 

Brilliant do. a little below Canis Minor, 

and was lost near Castor. 
Meteor appeared near Auriga, and was 

lost near Pollux. 
Do. southward from the E. of Canis 

Major. 
Small do. in the Milky Way, a little 

above the S. horizon. 

Meteor towards the E. of zenith 

Do. southward from Canis Major 

Do. iu the direction of N. to S. in the E 

Do. from E. towards Ursa Major 

Do. from below the zenith to the S 

horizon. 
Small do. from a little below the zenith 

towards the horizon. 

Do. in the N.E , 

Brilliant do. from the zenith towards W. 
Meteor from a Uttle below the zenith 

eastward. 

Do. from below the zenith to E 

Brilliant do. from below the zenith to- 
wards W. 
Meteor from a little below the zenith 

to the N. 
Do. along Aldebaran towards the E 

horizon. 
Do. from Ursa Major to the N. horizon.. 
Do. in the N. towards the horizon . 

Do. from Aldebaran to the E 

Do. in the N. passed towards Ursa 

Major. 

. Do. from Aldebaran to E 

Do. from the Pleiades towards W. . 
Do. in the N. passed towards the Pleiades 

in a W. direction. 
Three do. successively in the N. ; one 

along Aquila ; one towards Ursa 

Major, and one towards the hori 

zon. 
Meteor towards the eastern horizon .. 
Small do. from « Ursa Major to 

theN. 
Meteor between Aldebaran and Orion 
Do. to a Ursa Major from a little 

above it. 
Do. southward in the Milky Way . 
Do. in the Milky Wav ....v.... 



1,2 & 3 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 



Date. 


Bombay 
Mean Time. 


Description. 


Magnitude. 


Duration. 


1844. 


h ra 






sec. 


Nov. 14 


2 57 a.m.— 


Meteor to « Ursse Majoris from a little 
above it. 


1 






3 25 a.m.... 


Very brilliant do. westward from « Ursse 
Majoris. Its trail of light was visible 
for a second. 


1 


2i 




3 27 a.m.... 


Small do. westward by the S. side of 
Cassiopeia. 


6 






3 46 a.m.... 


Brilliant do. near the Milky Way, and 
was lost near « Eridani. 


1 






3 47 a.m.... 


Two smaller meteors appeared in the 
western side of the Milky Way, and 
were lost near the S. horizon. 


3 






3 48 a.m.... 


Brilliant meteor passed southward from 
the E. 


1 






4 42 a.m.... 


Meteor in the E. towards the hori- 


2 




15 


17 a.m.... 


zon. 
Do. in the S. 








57 a.m.... 


Do. in the W 


5 






1 32 a.m.... 


Do. from a little below Castor to the S. 


3 






1 41 a.m.... 


Brilliant do. from a little above the S.W. 
horizon to it. 


1 






1 46 a.m.... 


Small do. southward from ?; Orionis ... 


6 






1 57 a.m.... 


Very brilliant do. from the E. to the N. 


1 


2 




3 19 a.m.... 


Brilliant do. from a little above the S. 
horizon to it. 


1 


% 




3 31 a.m.... 
3 45 a.m.... 


Meteor westward from tc Arietis. ........ 


1 


2 




Very brilliant do. from a little below « 


1 


H 






Aurigpe towards the S. 








4 42 a.m.... 


Small do. eastward from Ursa Major... 


3 




16 


3 25 a.m.... 


Meteor to the N.W. from a little below 
Canis Major. 


2 






3 32 a.m.... 


Do. to the N. horizon from /3 Ursae 
Minoris. 


3 






3 46 a.m.... 


Do. northward from j3 Ursa Major 


1 






3 47 a.m.... 


Two do. to the eastern horizon from the 
northern side of the Planet Venus. 


1 






4 30 a.m.... 
4 45 a.m.... 


Meteor westward from the E 


3 






Do. from below the zenith to the E. . . . 


3 






8 10 p.m.... 


Do. from theE. towards the S.E. horizon 


3 






8 13 p.m.... 


Do. from the N.E. towards the N. from 
Aldebaran. 


3 




17 


2 38 a.m.... 
2 57 a.m.... 


Do. eastward from Canis Minor 


1 




Do. to the southern horizon from the 


3 








eastern side of a Eridani. 








4 17 a.m.... 


Do. down perpendicularly from Orion... 


1 


1 




4 30 a.m.... 


Do. near the zenith 


3 






4 42 a.m.... 


Do from a little below the zenith to E. 


2 


1 




5 03 a.m.... 


Do. from Venus toward the E. horizon.. 


1 






9 04 p.m.... 


Brilliant do. westward from Cassiopeia.. 


1 


2 


18 


2 27 a.m.... 


Meteor from a little below the zenith 
towards the S. 


2 


i 




2 47 a.m.... 


Do. in the S. towards Canis Major 


2 


i 




2 55 a.m.... 


BrilUant do. from a little above Canis 
Major towards the S. horizon. 


1 


i 




3 47 a.m.... 


Meteor in the S. dropped down towai-ds 
the horizon. 


2 


yf 


19..... 


2 35 a.m.... 


Very briUiant do. rapidly from a little 
above it to the N.E. horizon. 


1 






2 51 a.m.... 


Meteor a little above Ursa Major 


3 





REPORT — 1849. 



Date. 


Bombay 
Mean Time. 


Description. 


Magnitude. 


Dm-ation. 


1844. 


h m 






sec. 


Nov. 19 


2 57 a.m.... 


Meteor eastward from a little below 
Canis Minor, leaving sparks behind 
during its progress for half a second. 


2 






3 45 a.m.... 


Small do. descended from the zenith 
westward. 


5 






4 02 a.m.... 


Meteor westward from a Eridani 


3 




20 


2 21 a.m.... 
4 04 a.m.... 
7 57 p.m.... 


Do. in the E. ...; 


1 
2 

1 




Do. in the S 


Brilliant do. from the Pleiades towards 






the zenith. 








10 00 p.m.... 


Do. from a. Orionis to the S., with a 
little inclination to the W. 


1 




21 


1 30 a.m.... 


Large do. descended to the E. horizon 
from a little above it. 


1 


3 


22 


3 42 a.m.... 


Meteor to a Ursa Minor from the 
N.W. 


2 






4 57 a.m.... 


Do. from Ursa Major towards the E.... 


2 






5 3 a.m.... 


Do. from the Pleiades towards the W. 
horizon. 


3 




23 


3 52 a.m.... 


Do. in the N. near Ursa Minor. 






24 


4 34 a.m.... 


Do. from the S. towards the Pleiades... 


2 






4 47 a.m.... 


Do. from the S. horizon towards Venus.. 


2 






4 55 a.m.... 


Do. from a little below the zenith to- 
wards the E. 


2 




26 


4 48 a.m.... 


Do. in the S. 






27 


7 00 p.m.... 


Do. in the W. towards the horizon 


1 


1 



IV. Supplement to the Table in last Report of the British Association, from 
August 1846 to Juhj 1848. 



Date. 



1846. 
Aug. 8, 9. 

10 .. 

11 ,. 

Sept. (Middle) 



Nov. 8 

8,9 .. 
11 



12, 13, 14, 15 



Description. 



Night cloudy 

Clear interval about midnight ; 

15 meteors from 12'' to P 

32 do. from 1" to 2''. 
Clear, moonlight ; 41 meteors 

fromQHolOMl""; 18inN.W 

quadrant ; 23 in S.E. ; faint 

aurora. 
Numerous shooting stars .. 



Many 

Many ; brilliant . . 
Fall of an aerolite 



Many ; brilliant ; most N.E. and 
S.W. 



Place. 



Newhaven . . "I 
Connecticut J 



Ibid , 



lUyria and 
Dalmatia. 

Milan 

Parma 

Lowell, U.S... 

Parma 



Observer. 



Mr. Herrick 



Id. and Mr. 
Bradley. 



•■•{ 



M. Colla 



M. Mayer 

M. Colla 

Correspondent to 

M. Colla. 
M.CoUa 



Reference. 



Bulletin*, Acad. R. 
Bruxelles, 1847. 
201. 



Ibid. 



Ibid. 139. 

Ibid. 43. 

Ibid. 

Ibid. 

Ibid. 



* Some of the meteors noticed in the Number of the Bulletin here referred to, are the same as 
those recorded in the former Catalogue, and are therefore not here inserted, 



A CATALOGUE OF OBSERVATIONS OP LUMINOUS METEORS. 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1846. 










Nov. 13 


27 between 7" 11"" and 7" 53"". 


Milan 


M. Mayer 


Bull. Acad. R, 
Brux., 1847. 43. 






12, 13... 


During both nights 239 me- 
teors. 


Vienna 


Correspondent to 
M. Mayer 


Ibid. 








Dec. 9 


Many shooting stars 


Parma 


M. Colla 


Ibid. 


10 


Many do 


Ibid 


Id 


Ibid. 


21 

1847. 


A remarkable boUde (morning) 


Ibid 


Id 


Ibid. 






Jan. 10 


Many shooting stars 


Parma 


M. Colla 


Ibid. 268. 


Mar. 11,12,24, 


Many. On the 12th a faint 


Ibid 


Id 


Ibid. 


25 


aurora. 








April 19,20... 
May 26 


Many 


Ibid 


Id 


Ibid. 


lOi" 25"" P.M. A large meteor ; 


Rosehill, Ox- 


Rev. J. Slatter... 


Letter to Professor 




bluish white. Altitude about 


ford. 




Powell. 




12°orl5°in S.E. ; descended 










towards N.E. 








June 17-22... 


Many meteors 


Parma 


M. Colla 


Bull. Acad. R. 
Brux., 1847, 268. 








29 


9^ 48" P.M. ; altitude 52°, azim. 
50° W. A yellow Ught over 


Ibid 


Id. 


Ibid. 








the sky ; then from behind 










clouds a globe of fire de- 










scended slowly in direction 










of meridian, through 20° to- 










wards S, ; disappeared with- 










out noise. Mostly hid by 










clouds ; size could not be 










estimated, but seemed large. 








July 4,5... 
14 


A great number of meteors ... 
S" 45"" A.M. Violent explosions 


Ibid 


Id 


Ibid. 406. 
Appendix, No. 2. 


Hauptmanns- 


Correspondent to 




and a rushing noise ; then a 


dorf, near 


W.W. Smyth, 






narrow black cloud emitting 


and N.E. of 


Esq. 






coruscations ; divided and dis- 


Braunau, 








appeared. A meteorite seen 


Bohemia. 








to fall; imbedded itself 3 










feet deep in the ground. 










Another mass penetrated and 










shattered a house. 








14 


Large meteorite dug up, 14 feet 


Bohemia 


Correspondent to 


British Assoc.1848. 




deep, at See-Loeggen. 




Prof.Bogus- 
lawski. 


AtheniEum, No. 
1087, p. 866. 


22, 23.. 


A great number of meteors ... 


Parma 


M. Colla 


BulI.Acad.R.Brux., 
1847. 406. 






Aug. 9 


Eavlyinthe evening, 10 meteors 
in an hour ; towards mid- 
night, 20 meteors in an 
hour. 


Bruxelles Ob- 
servatory, 


M. Quetelet 


Ibid. 382. 




One remarkable at lO^ 25", 
appeared in Pegasus ; slow ; 


Ibid 


Id 


Ibid. 383. 








visible for 5 seconds; dis- 










appeared in Opbiuchus; no 










defined nucleus, but nebu- 










lous head. Expanded to 










about 30' diam., and so 










dissipated. 










Nine meteors from 9'' 25" to 
lO"" 20" with trains. 


Ghent 


M. Duprez 


Ibid. 




10 


Cloudy at Brussels. From 
9^ 20" to 9^ 55". 28 


AixlaChapelle 


M. Heis 


Ibid. 385. 










meteors. 









10 



REPORT — 1849. 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1847. 










Aug. 10 


Some with trains ; mostly in Via 
Lactea; one moving upwards ; 
20 in i liour. 


Munich ...... 


M. Robiano ...... 


Bull.Acad, R.Brux., 
1847. 386. 


11 


Great numbers ; 30 in an hour ; 
mostlv from N.E. to S.W. 


Brussels 


M. Quetelet 


Ibid. 383. 




From g^ 15°' to 12'' 15°" 66 
meteors ; 27 brilliant, with 


Ghent 


M. Duprez 


Ibid. 






trains looking towards E., or 










22 per hour (in former years 










21 per hour). 2? from N.E. 










to S.W. ; the rest in different 










directions. 










35 in 1 hour ; most towards W. ; 
many red ; some with trains. 


Bruges 


Dr. Forster 


Ibid. 384. 






From gi' to 13'' 30"" 501 ; num- 
ber greater as night advanced. 


AixlaChapelle 


M, Heis 


Ibid. 385. 






Emanating from a point ; JR 










42° ; dec. 55° S. 








7-13, 16, 17, 

23, 24 
Sept. 7 


[■ Great number of meteors. 
Large fire-ball ; bright ; blue ; 


Parma 

Bombay 


iLCoUa 


Ibid. 406. 
Bombay Times, 


A Correspondent 




from N. to S., then turned 






Nov. 1, 1847. 




nearly at right angles. Visible 






Appendix, No. 4 . 




5 or6sec.; then split into frag- 










ments and shower of sparks. 








Oct. 10 


100 in one hour ; maximum 
about 2 A.M., Oct. 11. 


Bruges 


Dr. Forster 


Bull.Acad. R.Brux., 
1847. 404. 




30 


Great numbers of meteors 

Large fire-ball ; nearly hori- 


Parma 


M. Colla 


Ibid. 406. 
Bombay Times, 


Bombay 


A Correspondent 




zontal from E. to W. ; then 






Nov. 7, 1847. 




fell perpendicularly into the 






Appendix, No. 4. 




sea. Very bright ; blue ; train. 








Nov. 13 


Cloudy ; clear interval from lO"" 
to 13'' 58-°. Several hundreds 


Bruges 


Dr. Forster 


Astr. Soc. Notices, 
ix. 37. 






of small meteors, white, with 










trains ; mostly N.N.W. One 










large ; slow ; across zenith 










to S.E. 








Dec. 20 

1848. 


Three meteors 


Ibid 


Id 


Ibid. 








Jan. 27 


S*" P.M. (daylight). Clear sky. 


Buckingham, 


The brother of 


MS. letter from 




A bright meteor passed from 


and at one 


Rev.J.Slatter, 


Rev. J. Slatter to 




S.W. to N.E., between 60° 


mile distant. 


and another 


Prof. Powell. 




and 30° alt. ; pear-shaped ; of 




Observer. 






a silvery whiteness, with a 










train which separated into 










several parts. Visible 3 sees. 








Feb. 15 


1'' P.M. A loud report and rush- 


Negloor, near 


Captain S. Win- 


Bombay Times. 




ing noise ; nothing seen to 


Dharwar, 


gate, Bombay 


Appendix, No. 5. 




fall, but dust rising. Meteo- 


India. 


Engineers. 






rite found several inches 
deep, 
l"" A.M. A large meteor, shaped 
like a kite, larger and 








March 8 


Slough 


Mr. Atkins, Cor- 


MS. letter. 






respondent to 


Appendix, No. 6. 




brighter than the moon, 




SirJ.Herschel. 






passed slowly and nearly ho- 










rizontally from W. to E. in 










the S. It appeared to issue 










from behind the clouds, and 










was lost behind them again. 










Seen also at Bath. 














- 





A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 11 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1848. 










April 6 


Soon after sunset. (V just 


Near Rosehill, 


Rev. J. Slatter... 


MS. letter to Prof. 




visible). A small meteor; 


about two 




Powell. 




very white ; moved from S.E. 


mUes S.E. 








towards S.W., and then fell 


of Oxford. 








nearly perpendicularly. 








12 


gh i5ra p_jj_ ^ meteor about 
the size and colour of An- 


Oxford 


Rev. J. Slatter... 


Ibid. 






tares ; moved slowly nearly 










horizontally along E. ; de- 










scended a little below a. Lyrse, 










and then disappeared. 








18 


After sunset, hardly dark. A 
meteor in S.S.E. appeared to 
ascend a little, and then de- 


Between Ox- 
ford and 
Rosehill. 


Rev. J. Slatter... 


Ibid. 




scended almost perpendi- 
cularly, increasing in bright- 
ness till it disappeared. 








July 13 


lO"" P.M. A bright meteor from 


Stone Easton, 


H. Lawson, Esq., 


MS. letter to Mr. 




S. to W. at about 35° alt. ; 


14 miles 


F.R.S. &c. 


Lowe. 




head " the size of a full-sized 


S.W. of 








cricket-ball ;" cream colour ; 


Bath. 








middle of train purplish red, 
hind part bluish green. 








15 


Ill" P.M. A meteor=star 1st 


Highfield 


E. J. Lowe, Esq. 


MS. list communi- 




mag. ; fell perpendicularly 


House, Not- 




cated to Prof, 




from 24 Camelopardalis (He- 


tingham. 




PoweU. 




velius) through (B.C.) 43 










and 42 Camelopardalis, and 










through (B.C.) 14 Lyrae. 









Note. — Thus far the present Catalogue coincides in time with the latter part of the former. On 
comparing them we may remark — 

1846. Aug. 8, 9, 10. — The observations at Newhaven, U.S., and at Dijon, agree in showing 
numerous meteors. 

Dec. 21. — May the large meteor observed at Nottingham at 9 p.m. be connected with the bolide 
at Dijon " in the morning ?" 

1847. Jan. 10, 11. — Many meteors were observed both at Nottingham and Parma. 
June 21. — Several at Nottingham. 17-22. Many at Parma. 

Aug. 9, 10, 11. — Observations agree at Nottingham, Durham, Oxford, Belgium, and Aix la 
Chapelle. 
Nov. 12, 13. — Observations agree at Durham, Bruges, and Benares. 

1848. April 6. — The same meteor seen by Mr. Symonds and Mr. Slatter. 





V. The Table in Report 184.8, 


continued. 




Date. 


Description. 


Place. 


Observer. 


Reference. 


1848. 
Aug. 1 


10" 25"". Large and brilliant ; 
from near 37 (Hevelius) Ursae 
Majoris, through X Urs. Maj. 
to 21 (B.C.) Leonis Minoris ; 
with a train. 

lO^SO-" to 10" 50-". Several 
small, vrith trains, in An- 
dromeda, Pegasus, and Cas- 
siopeia. 


Highfield 
House, Not- 
tingham. 

Ibid 


E. J. Lowe, Esq. 
Id 


MS. communica- 
tion to Prof. 
Powell. 

Ibid. 







12 


REPORT— 1849. 






Date. 


Description. 


Place. 


Observer. 


Reference. 


1848. 










Aug. 1 


lO*" 51'^. Small, withtrain, from 


Highfield Ho., 


E. J. Lowe, Esq. 


MS. com. to Prof. 




a Androm. to a Pegasi. 


Nottingham. 




Powell. 




Hh 701 3o^ Small, extremely 
rapid ; parallel to horizon 


Ibid 


Id 


Ibid. 












from tail to head of Vulpe- 










cula, with streamers. 










11'' 8"". Small, with streamers ; 
from 10° below Delphinus 


Ibid 


Id 


Ibid. 












through d Antin. ; rapid. 










ll"" 12"°. Small, with streamers, 
perpendicularly down from 


Ibid 


Id 


Ibid. 












S Sagittarii. 










11'' 15">. Bright; red; with 
train, inclined 45° towards 


Ibid 


Id 


Ibid. 












\V. horizon; first seen near 










r Urs. Maj. ; feU to X Urs. 
Maj. 
11'' 41"". Small ; from a Del- 
phini towards S. ; vanished 










Ibid 


Id 


Ibid. 












after moving 14°. 










11'' 42". Small; moved verti- 
cally upwards from a Del- 


Ibid 


Id 


Ibid. 












phini to hind leg of Wolf. 








2 


IC 44"". Brilliant; path in- 
clined at about 45° from a 


Ibid 


Mrs. Lowe 


Ibid. 










Androm. to Triangulum. 










10'' 49"". Parallel to horizon 
from i to T Cygni. 


Ibid 


Id 


Ibid. 










7 


11'' ig-". Slow, from S. towards 
E. at about 45° ; first seen at 
); Antin. and fell slightly to 
E. of /3 Capricorui. 


Ibid 


E. J. Lowe, Esq. 


Ibid. 


9 


From 9'' 45"" p.m. to 11. 25 me- 
teors; from 12'' to 1" 30" 


Paris? 


M. Goujon 


Comptes Rendus, 
1848. ii. 185. 






70. Mostly from N. to S. 










A list of the number seen on~ 










different nights, during a 










part of July and August ; 






Ibid. 




showing a maximum on 
August 9, 10. 


Ibid 


M. CouUier Gra- 






vier. 






During the night of 9, 10, 










414 seen. 










9" P.M. A remarkable numbe 


r Near Hamp- 


Su- R. 11. Schom- 


Athenajum, No. 




of shooting stars, apparently 


ton. 


burgk. 


1085, p. 807. 




lower in the atmosphere thai 










usual ; of a dark red colour 






1 




direction mostly S.E. 










[No meteors on the 8th.] 










9^ P.M. to 9'' SO-". Six small 










meteors, with trains, fol- 










lowing in parallel directions 










from S.E. to S. ; inclined 










at about 30° to S. horizon. 






■ 




Flashes of Ughtning in S. 
9^ 30-". A brilliant flash, or 


St. Leonards, 


Prof. Powell. 






Sussex. 








coruscation, nearly at S. 










point of horizon. 










9'' SS"", A bright meteor from 










S.E. to S. (as before) ; 










another from zenith ; 










nearly parallel. 









A CATALOGUE OP OBSERVATIONS OF LUMINOUS METEORS. 13 



Date. 



Description. 



Place. 



Observer. 



Reference. 



10 



9^ 50™. Small meteor from~| 
S.E. to S. (as before) ; 
another from zenith ; y St. Leonards, 
nearly parallel. j Sussex. 

10". Clouded over 

From 9^'' to IH''. 18 meteors ; Ghent 

most from N.W. to S.E. ; one 

N.E. to S.W. (moonlight). 

ll^" 19"". One large; appeared Ibid., 

near head of Medusa ; moved 

E. ; red ; train of sparks. 

Before 11" p.m. Several small Highfield Ho., 

falling stars. Nottingham 

llh 27"'. One; blue; rapidly Ibid, 

from 3° below a Androm. ; 

parallel to horizon to e Pegasi. 

lit" 29". Red ; shot downwards Ibid., 

at 25° incl. from /3 to X 

Pegasi. 

11'' 34"". Bright; fell rapidly Ibid., 

from 35 (Hevel.) Cassiopeia, 

through 17 Camelopardalis, 

lit" 37™. One through ^3 Pegasi Ihid., 

to Antinous, " in a curious 

curve, which was inverted 

with respect to the horizon, 

towards which it was fall 

ing." (probably convex to the 

horizon ?) 

U'' 52™. One from X to « Dra- Ibid., 

conis ; streamers. 
iP 54™. Two together; one Ibid., 
from X Cephei towards y 
Urs. Min., the other from 
X to J/ Draconis ; streamers 
IP 57™. One from 4° above Ibid., 
Polaris through jj Draconis 
many smaller during the 
evening, with tails. 
Ill- 58™. Bright ; from x Ce- Ibid., 

phei to Lacerta. 
12'' 4™. Two together, perpen- Ibid., 
dicularly downwards ; one 
slightly W. of «, and through 
j3 Urs. Maj.; the other 
1° E. of S, and through 
Urs. Maj. 
12" 5™. Two, both perpendicn- Ibid., 
larly downwards ; 1st through 
y Urs. Maj. ; 2nd from 
Y Cephei. Many smaller. 
11" 41™ P.M. One ; veiy rapid •,jlbid., 

from Shedii to y Cephei. 
11" 44™. One; very rapid ; Ibid., 
from a Cephei through y 
Draconis and j] Herculis. 
Ilk 50"". One ; small ; 5°underilbid. 
Polaris ; rapid ; horizontal. 
Many small ones all night, 
especially in Cepheus, Ursa 
Minor and Draco. 



Prof. Powdl. 



M. Duprez 



Id. 



E. J. Lowe, Esq. 



[d. 



Id. 



Id. 



L'Institut,No.783, 
p. 6. 

Ibid. 



MS. com. to Prof. 

Powell. 
Ibid. 



Id. 



Id. 



Id. 



Id. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 



14 



REPORT— 1849. 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1848. 










Aug. 10 


Cloudy till 111, thence to 12| 


Ghent 


M. Duprez 


L'Institut. No. 783, 




9 meteors ; most from N. to 






p. 6. 




S. ; then cloudy. 










Partially cloudy, fiom 1 2'" to"| 










12'' 45".. 30 'seen through 










clouds ; bluish white, with 










red train. 










Clearer from l*- 41" to 2'' 










41™; 117 seen; perhaps}- 


Aimagh 


Rev. Dr. Robin- 


British Association, 




smaller ones not noticed. 




son and As- 


1848. Sec. Proc, 




Some large and brilliant; 




sistant. 


p. 37. 




motion mostly directed to- 










wards 7] Ophiuchi, nearly 










f N. of the prime vertical. J 










No meteors before 9^ 30™ p.m. 


St. Leonards, 


Prof. Powell. 






then partially clouded. No 


Sussex. 








meteors seen. 








11 

21 


Entirely clouded 


Ibid 


Id 


Ibid. 

MS. communica- 


Ill" 45'". A brilliant caudate 


Highfield 


E. J. Lowe, Esq. 




meteor, larger than Sirius 


House, Not- 




tion to Prof. 




from Delphinus to Al- 


tingham. 




PoweU. 




genib. 










ll*" 47'". A small one from y ' 










Urs. Min., perpendicularly 










downwards. > 
Many smaller ones about | 


Ibid 


Id 


Ibid, 








midniglit. J 








23 


U*" 40'". Bright; perpendicu- 
larly down from 1° N. of 


Ibid 


Id 


Ibid. 








y Urs. Maj. 










Several smaU ones within the 
last few minutes in Draco 


Ibid 


Id 


Ibid. 








Andromeda, Pegasus, anc 










Ursa Minor. 








28 


lO*". Small meteors in Ursa Mi- 
nor and Draco. 


Ibid 


Id 


Ibid. 






29 


Many in Urs. Maj. and Min. ... 
A meteor (no particulars 


Ibid 


Id 


Ibid. 

Comptes Rendns, 
1848. ii. 297. 


Paris 


M. Dubois 




given). 




Sept. I 


7'' 45"". A meteor (no particu- 
lars given). 


Saflfres Cote 
d'Or. 


M. Boucher 


Ibid. 




8'> P.M. Brilliant meteor ; green- 


Brussels 


M. Putzeys 


L'Institut, No. 783, 




ish light ; slow ; nearly hori- 






p. 6. 




zontal, from W. to E. 










" Bright globe of fire," from 
N.W. to N.E. ; sky iUumi- 


Nevers and 
Caen. 


Correspondent to 
Nevers Jour- 


Ibid. 




nated after disappearance. 9^ 




nal. 






the same ? 








4 


gh 59"' p_j^j_ ^ meteor from 


Highfield 


E. J. Lowe, Esq. 


MS. communica- 




about j; Antinoi to tt Sagit- 


House, Not- 


and A. S. H. 


tion to Prof. 




tarii, = 6 times 2/. ; dark 


tingham. 


Lowe, Esq. 


Powell. 




straw-colour, changing to 








pm-ple ; emitted sparks ; fa- 










ded away, leaving a streak of 










blue light 4° in length, and 










25' in breadth, perpendicular 










to horizon ; lasted f rain. 










before it finally vanished ; a 






S 




small falling star crossed in 






1 




same track. 










A CATALOGUE OP OBSKRVATIONS OP LUMINOUS METEORS. 15 



Date, 


Description. 


Place. 


Observer. 


Reference. 


1848. 










Sept. 4 


^h P.M. In the S.S.W. a meteor 


Worthing, 


Alfred H, Lowe, 


Ibid. 




" like a sky-rocket, or rather 


Sussex. 


Esq. 






an oblong piece of fire," first 










blue, then fiery red, emitting 










sparks, continued for 1 or 2 










seconds, and disappeared. 










leaving a blue mark visible 










for many seconds, from Altair 










perpendicularly down. Seen 










also atFecamp, in France, like 










a globe of fire emitting sparks. 










Soon after a small falling star 
moved in the same path. 


Ibid 


Id 


Ibid. 


[Nottingham 




6 


12'' 30". A few falling stars ... 


Highfield Ho., 


E. J. Lowe, Esq. 


MS.commun. 


8 


gh 50"' P.M. A small luminous 


Pisa 


J. Irving, Esq.... 


Letter to Prof. 
Powell, in Ap- 




ball from N.W. to S.E. ; dis- 






sipated 'before reaching the 






pendix, No. 7. 




horizon. 








19 


12''. One from x Draconis to 


Highfield Ho., 


E. J. Lowe, Esq. 


MS. Communica- 




midway between d and i 


Nottingham 




tion. 




Urs. Maj. 








24 


\1^ IS", A caudate meteor= 
1st mag. ; slowly down from 


Ibid 


Iij 


Ibid. 








3° E. of y Urs. Maj. to v// 










Urs. Maj. 








Oct. .■) 


Ijh 27"' P.M. Smallmeteor, from 
a Pegasi through Cassiopeia. 


Ibid 


[d 


Ibid. 








n^ 33". Do. with many red 
sparks ; from 5° below Ca- 


Ibid 


Id 


Ibid. 








pella ; moved 1° and disap- 










peared. 








18 


lO*" 46". During a magnificent 
aurora, a fine caudate meteor 


Ibid 


Id 


Ibid. 








fell through Pegasus Square. 










Several falling stars. 








19 


S*". One, from 1° below jj Her- 
culis, horizontally to 1° above 


Ibid 


Id 


Ibid. 








i Herculis. 








21 


ll** ll". One from between the 
Pointers to y Urs. Maj. 


Ibid 


Id 


Ibid. 






22 


Many ; one at 8" 50™ = 1st mag. 
fell through the Wagon in 


Ibid 


Id 


Ibid. 








Urs. Maj. 








27 


10'' 30"". Large and brilliant, 
through Aldebaran down to 


Ibid 


Id 


Ibid. 








Betelgeuse. Many others. 










S^ P.M. Large and white, vrith 
a train; = Venus; passed 


Oxford 


Mr.G.A.Rowell. 


Verbal Statement 
to Prof. Powell. 








through Taurus in a line 










parallel to Aldebaran, anc 










the two adjacent stars, and 










disappeared at a distance 










beyond Aldebaran, nearly = 










that of Aldebaran from the 










next star ; at the same time 










a bright aurora*. 1 







HoTB. — 1848, Sept. 4. — The meteor seen at Nottingham was probably the same with that seen 
at Worthing and Fecamp ; the stars rj Antinoi, Altair (« Aquilae), and n Sagittarii, all lying not 
much out of the same line, passing down to the horizon at the time. 

* See also Phil. Mag. Dec. 1848, calculation by Sir J. Lubbock, and Phil. Mag. March 1849. 



16 



REPORT — 1849. 






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A CATALOGUE OF OBSERVATIONS OP LUMINOUS METEORS. If 



Date. 



13, 14.. 



17 



21 
29 



Description. 



Place. 



Paris ? 



1849. 



ll"" 50"". A fine globe meteor ; 
pale blue; = 5 times If.; 
from TT Pegasito near Delplii- 
nus ; perpendicularly down 
for 30°, when it burst and 
disappeared. 
From 12h 45'" to S^ 15'" a.m 
on the 14th. 10 meteors. 
M. Coulvier Gravier, calcu 
lating on his system, finds the 
horary number below the 
average, 
l** 15°' A.M. A small bolide 
11 •> 12" P.M. A meteor with a 
bright train, moved from 
about 6° or 8° N. of the 
Pleiades through the zenith, 
to about 30° or 35° above 
the horizon, about N.N.W., 
when it disappeared ; in about 
4 seconds a bright rose-co- 
loured aurora had appeared 
during the evening, and at 
this time assumed the ap- 
pearance of beams converging 
towards the zenith. The 
course of the meteor was ex- 
actly along one of these beams. 
During an aurora. A bright 
blue-globe meteor fell from 
CapeUa towards the N. ho- 
rizon, leaving a "stream of 
stars." 
ll*" 4"". A small falling star 
from the cupola of the aurora 
(then situated at 21 Persei), 
to near the W. horizon; 
seemed brighter than usual 
for their size, and very rapid. 
One from zenith through 80° 
in 1^ second. 
During an aurora, four small 
meteors fell into the aurora 
and disappeared, 
igi- 0'" 50'-35. Grantham mean 
time of disappearance. [The 
time taken from transit of /3 
Leonis ; my long. I reckon 
2"' 36' W. from London ; 
but this perhaps 4 or 6 sec. 
too great.] A meteor much 
larger and brighter than 11 
moved nearly horizontally 
about 10° while seen ; mo- 
derate velocity ; colour pale 
rose. Vanished after 1 second, 
almost perpendicularly below 
2/. , and about four times as 
far from 1^. a.& li. from Re- 
gains. No train ; but per 
haps invisible from light. 



Highfield 
House, Not 
tingham. 



Ibid 

Oxford . 



Observer. 



E. J. Lowe, Esq 



M. Coulvier Gra- 



Id 

Mr.G.A.Rowell, 



Mr. Lawson's 
Observatory, 
Bath. 



Ibid. 



Reference. 



MS. 



Comptes Rendus, 
1848. ii. 521. 



Ibid. 

Verbal statement 
to Prof. Powell. 



E. J. Lowe, Esq, 



Rosehill, Ox- 
ford. 

Grantham, 
Lincoln- 
shire. 



Rev. J. Slatter.. 



J. W. Jeans, Esq 



Id. 



MS. 



Ibid. 



Letter to 
Prof. Powell. 

Mr. Lowe's MS. 



18 



REPORT — 1849. 



Date 


Description. 


Place. 


Observer. Reference. 


1848. 










Nov. 30 


IP. A fine caudate meteor 
tlirough y Gemini. 


Highfield Ho., 
Nottingham. 


E. J. Lowe, Esq. 


MS. 


Dec. 13 


ll*". A small falling star near 
Aldebaran. 


Ibid 


Id 


Ibid. 






1849. 










Jan. 28 


8'' 15" P.M. A meteor = twice 


Bath. Obser- 


Mr. and Mrs. 


Ibid. 




Tf. ; blue, with slight train of 


vatory of 


Lowe. 






sparks ; moved slowly ft-om 


H. Lawson, 








Castor to near Regulus. 


Esq. 






Feb. 10 


A bright meteor 


Hid. Ho., Not. 


A.S.H.Lowe.Esq. 
A Correspondent 


Ibid. 


24 


A meteor 


Madras 


Bombay Times. 


28 


IC" 15'" P.M. During an aurora, 
a meteor with train ; lost be- 
hind clouds at about 15° alt. 


RosehiU, Ox. 
ford. 


Rev. J. Slatter... 


MS. 


March 6 


e*" 8"" P.M. A brilliant white 


Mill-yard, 


W.H.Black,Esq. 


Letter to Prof. 




large meteor fell from a little 


Whitechapel, 




Powell. Ap- 




below and S. of the moon. 


London. 




pendix, No. 8. 




and after H sec. exploded 










with a greenish and red flash, 










at about 12° alt. in S.E. 








19 


6^ 30'" P.M. A brilliant green 


Bombay, 


Numerous Ob- 


Bombay Times. 




meteor ; direction N.E. ; ex- 


Poona, Au- 


servers. 


Appendix, 




ploded and separated into 


rungahad. 




No. 9. 




red particles or sparks. 


Sholapoor, 








("Some discrepancies in the "1 


Surat, and 








1 observations at different 


other places. 








■{ places render it proliable ■ 










that two distinct meteors 
I were seen. 
















23 


A small meteor 


Bombay 

Cochin 


A Correspondent 
Id 


lb. lb. No. 9. 


26 


.\ bright meteor = Venus; nu- 
cleus green ; tail red; direc- 


lb. lb. No. 10. 








tion N.W. ; burst into frag- 










ments. 






[July 11, 1849. 


April 4 

10 

13 


A m eteor 


Delhi 


Id 


Bombay Times, 

Ibid. 

Mr. Lowe's MS. 


One large meteorand 2 small... 
A fine meteor, from near Spica 


Ahmednuggur 
Highfield Ho., 


Id 


S. Watson, Esq.. 




Virgiuis to S. horizon. 


Nottingham. 








9^ P.M. Brilliant, with blue 


Bombay and 


Several Obser- 


Bombay Times. 




train from W. to S.E. ; no 


llingolee. 


vers. 


Appendix, No. 




explosion. 






11. 


19? or 26? 


Brilliant ; burst into sparks ... 


Bombay 


A Correspondent 


lb. lb. No. 12. 


30 

20 


Bright; no explosion 


Poona 

Highfield Ho., 


Id 

E. J. Lowe, Esq. 


lb. lb. No. 12. 
MS. 


Ill" P.M. A small falling star, 




downwards from y Librai. 


Nottingham. 








ll"" 15'". Small ; perpendicu- 
larly from Aldebaran ; rapid ; 


Ibid 


Id 


Ibid. 








left streamers. 










11'' 19'". Small; vertically up- 
wards from near fi Lyra;. 


Ibid 


Id 


Ibid. 












IT^ 20'". Small; downwards; 
inclined about 45° from S 


Ibid 


Id 


Ibid. 






Virginis to near £ Crateris. 










11'' 24'". One; from \ Urs. 
Maj. through 37 Leonis 


Ibid 


Id 


Ibid. 








Minor. 










ll'' 25'". One from Dubbe 
to X Urs. Maj. 


Ibid 


Id 


Ibid. 








11'' 27'". One; perpendicularly 
down from Coma Berenicis, 


Ibid 


Id 


Ibid. '\ 












passingslightly to E .of Deneb. 
















i 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 19 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1849. 










April 26 


Lli-Sg'". Small; horizontally 


^ighfield Ho., 


S. J. Lowe, Esq, MS. | 




towards Polaris, from S Dra- 


Nottingham. 








conis to r Draconis ; blue ; 










rapid ; left sparks. 










12''. One, from »j Urs. Maj. 1 
through a Draconis to y Urs. 


bid 


[d 


bid. 












Min. ; yellow; quick. 










12'' 7"'. Small; horizontally] 
from S Draconis to r Dra- 


bid 


[d Ibid. 1 












conis; blue; rapid; left 










sparks. [Same track as that 










at 11'' 59'".] 










12'' 15'". One ; horizontally from 
Atair through S Aquite; 


[bid 


Id 


[bid. 












rapid ; yellow ; left sparks. 








28 


11'' 7'". Small ; just above /3 & 
y Draconis. 


[bid 


Id 


Ibid. 












HI'S'". One, crossed? Draconis. 

8'' P.M. Meteor of elongated 

shape ; brightness = 1st mag.; 


[bid 


Id 


Ibid. 


30 


[jiege 


M. Koninck 


L'Institut,No.808, 








p. 206. 




slow, with train ; descended 










to N W. horizon ; inclined 










at 45°. 






[pendix. No. 12. 




Bright meteor ; no explosion.... 
A meteor • 


Poona 


A Correspondent 
Id 


Bombay Times, Ap- 


May 2 

6 

8 


Bombay 

Karrachee . . . 
Highfield Ho., 


Ibid. 


A meteor 


Id 


lb. July 11, 1849. 
Mr. Lowe's MS. 


9'' 18'" P.M. A globe meteor 


Rev. K.Swann... 




from £ Herculis to (i Lyrae. 


Nottingham. 








[These positions of its path 










were estimated from a Lyrse, 










since the full moon prevented 










smaller stars being seen.] 










Motion slow ; colour red ; 










size and brilliancy about = a 










Lyrae, the moon shining on 










both ; path behind light cirri ; 










no streamers. 








11 


11'' 16™. FalUngstar nearSpica 
Virginis. 


Ibid 


E. J. Lowe, Esq. 


MS. 




11'' 33'". Bright falling star; 
yellow ; small train ; from a 


Ibid 


Id 


Ibid. 












Draconis through % to X 










Draconis. 








13 


10'' 3'". Do. small ; slight train ; 
yellow ; rapid ; from c to be- 


Ibid 


Id 


Ibid. 












tween Capella and /3 Aurigae. 










IP 9'". Do. small ; rapid ; from a 
Draconis to Coma Berenicis. 


Ibid 


Id 


Ibid. 










22 


11'' 11"". Do. small; rapid 
yellow; from Muriackto be- 


Ibid 


Id 


Ibid. 








tween Arcturus and j/ Bootis 








June 13 


12''. Do. = Sirius ; from Algenil 
to a. Arietis. 


Ibid 


A. S. H. Lowe, 

Esq. 


Ibid. 


16 


11" 28'". Do. = 1st mag. ; rapid 
yellow ; from 5° below Po- 
laris, downwards to 20' 
shghtly W. of 42 Camelo 
pardalis. 


Ibid 


E. J. Lowe, Esq 


Ibid. 




IP 32"'.Do. = 3rd mag.; from 
y Urs. Min. to t Urs. Maj. 


[bid 


Id 


Ibid. 








. 


rapid; yellow. 






1 



c 2 



20 



REPORT— 1849. 



Date, 



Description. 



Place. 



Obsener. 



Reference. 



1849. 
June 17 . 



25 



23 



27 



30 



July 4 



10 



16 



1 P g™ 30'. Small falling star ; 
yellow; slow; from 41 Com 
Beren. to 1° W. of i Virginis. 
ll"" 10'". Do. from Arcturus, 
perpendicularly down to r 
Virginis. 
g*" 12'" P.M. A meteor; white 
tinged, slightly orange ; at 
first = 5th mag.; increasing 
in brightness till brighter 
than ^ ; moved E. from near 
j; Aquilje for about 15°, 
and disappeared near t Del- 
phini ; just before disappear- 
ance a fragment detached 
and then others smaller,which 
all followed in same track.. 
lO*" P.M. Very brilliant from S 
to W. ; e.xploded at about 
60° alt., leaving luminous red 
fragments ; about 5 minutes 
after sound heard Uke ord- 
nance. 
11'' 25"". =lst mag. ; yellow; 
rapid from o Arcturi [Bootis] 
passing 1° N. of Arcturus, 
and fading away between r 
and V [Bootis]. 
Uh 26"' 30'. Small ; moved 1' 
horizontally ; 3° above s Vir- 
ginis. 
11" 33'". =2^ ; small train 
yellow ; slowly from a. Ophi- 
uchi towards W., curving 
towards S., through y Her- 
culis and y Serpentis. 
11'' 43°'. = 2/. ; rapidly from 
Kochab, between AJioth and 
Weizar, and faded away near 
C.H. 120 Canis Venatici ; 
path inclined about 50° to 
horizon ; left train of bright 
pale red sparks for ^ sec. 
11* 59"'. =lst mag.; light red 
no train ; slowly from o 
Cygni, down through y Cygni 
to y Equulei. 
11'' 26"' P.M. Small; yellow; 
slow ; from a to % Draconis. 
HI'S*" P.M. Globe meteor=5 
times 2/. ; nearly pale bkie ; 
conical ; slow.without sparks, 
from about ?; Pegasi; through 
a Andromedaj to about 
Piseium. 
Ijh 28'". =twicR 1st mag.; pale 
red, with long train ; rapid 
from (x)^ Cygni to o' Cygni. 
11" 40'". =2nd mag.; blue; 
rapid ; through j3 and a 
Equulei. 



Highfield Ho. 
Nottingham 



Ibid. 



E. J. Lowe, Esq. 
Id 



Obsei-vatory, 
Cambridge, 
U.S. 



Prof. Bond 



MS. 
Ibid. 



American Journals 
Morning Post, 
July 11,1819. 



Kurrachee . . 



Highfield Ho., 
Nottingham. 



tV Correspondent 



E. J. Lowe, Esq. 



Ibid.. 



Ibid. 



Ibid.. 



Ibid. 



Ibid.. 



Ibid 



Ibid.. 



Ibid. 



Id. 



Id. 



V. S. H. Lowe, 
Esq. 



E. J. Lowe, Esq. 
Id 



Bombay Times, 
July 11, 1849. 



MS. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 
Ibid. 



A CATALOGUE OF OBSERVATIONS OP LUMINOUS METEORS. 21 



Date. 



1849. 
July 20 ., 



21 



22 
23 



Description. 



Place. 



121' 4°!^ = 1st mag. ; yellow, Highfield Ho., 

with stream ; slow from Nottingham 

No. 3 Lacertse to y Cassio- 

peiae. 

12'' 12"'. Small, with streamers ; Ibid. 

rapid from i Cassiopeia; ; in 

clined at 45° downwards to 

wards N. 

12'' 16™. Small, with streamers ; Ibid. 

pale red ; rapid from H 6 and 

H 8 Camelopardalis to aPersei. 

12'' 22"". Small ; red, with tail ; Ibid. 

slowly downwards at about 

45° ; from 2° S of hi and 

about the same alt.through3°. 

12'' 32". Small ; no tail ; yel- Ibid. 

low ; rapid ; from /3 Pegasi to 

X Andromedse. 

10'' 54"". Small ; rapid ; through Ibid. 

30' to N. from « Cephei. 
11" 5™. = 2nd mag.; yellow ; Ibid, 
rapidly from (o^, w^ and w^ 
Cephei to a Cephei. 
Ilk 20"". Do. small ; light red ; Ibid, 
rapidly from Delphinus, 
nearly perpendicularly down 
to 7l'Antinoi. 
11" 25"".= lstmag. ; red ; train Ibid., 
of sparks ; rapid ; nearly ho- 
rizontally towards S.W.from 
Dubbe, to 1° below Alioth. 
lib 42m. = 1st mag.; red; Ibid, 
splendid stream of Iight,5° in 
length ; slow ; from \ An 
dromedae to fi Cassiopeiae. 
11" 45"". Sm. ; red , with stream ; Ibid. 

rapidly from /i Cassiopeiae. 
Ill" 47"". Small; yellow, withlbid^. 
tail ; rapid ; inclined at 45'' 
towards S. from d Pegasi to 
fj, Aquarii. 
11'' 49"". = Istmag.; dark green ; 
rapidly inclined at 45°towds. 
S. from K Pegasi to y Aquarii. 
From 9''30"'to 10p.m. 5meteors. Jersey 
10" 37"" P.M. A meteor about Oxford. 
= lst mag.; white, with 
train ; appeared from behind 
buildings ; passed below Arc- 
turus and i] Bootis, parallel 
to the line joining them, and 
at a distance nearly = that 
of those stars from each 
other; disappeared without 
explosion, at a distance below 
and beyond jj Bootis, about 
double its distance from 
which gives (by the U.K.S. 
star map) for the point of 
disappearance aboutRA.200° ; 
Decl. 9° N. 



E. J. Lowe, Esq. 



Observer. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Ibid. 



Reference. 



MS. 



Ibid. 



Ibid. 



Ibid, 



Ibid. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid, 
Ibid. 



Id. 



Rev. J. Slatter. 
Prof. Powell.... 



Ibid. 

[Powell. 
Letter to Prof. 



22 



Date. 

1849. 
July 23 • 



27 



24 



REPORT — 1849. 



i 



Description. 



IC 40"° 309. Small; yellow ; Highfield Ho 

no tail ; rapidly from a Cephei Nottingham. 

to Polaris. 
lOh 42" 30'. Small ; red ; slight Ibid.. 

tail ; rapidly from K Cygni to 

a, Cephei 
lO"* 43'". Small ; from -k Cas- Ibid. 

siopeiae to r] Persei. 
IC' 4.5'". Small; red; tail ; Ibid.. 

rapidly from y Sagittae to y 

Aquilae. 
lO"" 46"'. Small; yellow; no Ibid.. 

tail ; rapidly from t Cassio- 

peise to % Andromedse. 
lO'' 49'". Small ; yellow ; slight Ibid.. 

tail ; rapidly from 40° Dra- 

conis to H 4 Draconis 
ll"" 0"'. Small ; yellow ; no tail; Ibid. 

rapidly from I Cygni to tt 

Pegasi. 
ll"" 7"". Small ; red ; tail ; Ibid.. 

rapidly from /3 Cephei to 

Cephei. I 

U'' 10'" 30'. Fine ; = 1st mag. ; Ibid 

light green ; no tail ; rapidly 

from No. 7 Camelopardalis 

to /3 Aurigae. 
11" 20'". Small, with stream ; Ibid. 

yellow ; rapidly from \ An- 

drom. to 1° below ir Cas- 



Place. 



siopeiae. 
U" 21'". Small ; red; tail; 

rapidlv from a to rj Pegasi. 
11'' 23"' 30'. Small ; yellow ; no 

tail ; rapidly from tt Pegasi 

to -^ Andromedse. 
W" 29'". = 2nd mag. ; red, with 

streamers; slow;fromaCephei 

to 1} Persei. 
llh 31"'. = 1st mag. ; dark red ; 

streamers ; quickly from 

Lacertae to % Andromedae. 
ll"" 32'". = 2nd mag.; yellow; 

no tail ; rapidly from i Cephei 

to 7 Cassiopeice. 
11'' 33"'. Small; yellow; slight 

tail ; rapidlv from a. Cephei 

to H 33 Cygni. 
11'' 34'". Small ; train ; yellow ; 

rapid from j; Cephei to 

Cephei. 
11'' 40'". = 3rd mag. ; red; 

stream ; rapidly from x •'^'^ 

droni. to 56 Pegasi. 
10'' 40'". Small ; rapid ; in the 

line from »; Urs. Maj. to 

r] Eootis ; disappeared a httle 

above the latter. 
11'' 22'" 30'. Small, with tail; 

blue ; rapidly from 43 Came- 
lopardalis to r Urs. Majoris 



Ibid.. 
Ibid., 



Ibid. 



Ibid. 



Ibid.. 



Ibid.. 



Ibid. 



Ibid. 



Oxford. 



E. J. Lowe, Esq. 



Observer. 



Keference. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



Id. 



MS. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 

. Ibid. 



Ibid. 



Ibid. 



liiid. 



Ibid. 



Ibid. 



Ibid. 



Highfield Ho., 
Nottingham. 



Prof. Powell. 



E. J. Lowe, Esq. 



MS. 



A CATALOGUE OP OBSERVATIONS OF LUMINOUS METEORS. 23 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1849. 
July 24 

26 

27 


Ilk 24"' 30'. Small; blue, with 
streamers ; rapidly ; from H 
35 Cassiopeiae to C.H. 155 
Caraelopardalis. 

nh 29"". Yellow i slight stream- 
ers ; rapid ; from y Persei to 
H. 14 Caraelopardalis. 

11'' 37'". = 3rd mag with a con- 
tinuous strealcof blue; rapidly 
from ? Cephei to 3° beyond 
H 43 Cephei. 

11'' 42°'. Small; yellow; no 
tail; swiftly from » Aquarii 
to 71 Antinoi. 

11"' 43'". Small ; continuous red 
train ; rapidly from 29 Vul- 
peculae to near p Delphini. 

11" 46"". Small ; no tail ; swiftly 
from X to a Pegasi. 

11" 59"'. Small; blue, with 
continuous stream ; rapidly ; 
perpendicularly down from 
86 Pegasi, through 35 and 36 
Piscis. 

12'' 1"'. Small ; rapidly from v 
Cygni to Delphinus. 

12'' 7'". = 1st niag.; having con- 
tinuous bright red streak ; 
afterwards l)roken into 
streamers ; from ] 7 Vulpe- 
culae to Vega. 

12" 14"". Very small ; yellow ; 
with continuous ray, nearly 
perpendicularly down ; ra- 
pidly from y Pegasi to i 
Piscis, 

12" 19"". Small,with continuous 
blue ray; rapid; nearly ho- 
rizontal ; from Q Persei to a 
little above a. Persei. 

11" 5". Small ; rapid ; from 109 
Herculis through a. Ophiuchi. 

11" lO". Small; yellow; no 
tail ; rapid ; from 'i Andro- 
medae to /3 Arietis. 

11" 11"'. Small; no tail; light 
red ; rapid ; from y Cephei to 
S Urs. Min. 

1 1" 1 5"*. = 3rd mag. ; red ; tail ; 
rapid ; from y Cephei to i 
Urs. Min. 

11" 22"'. Small; tail; yellow; 
rapidly from H 3 Camelo- 
pardaiis to a little N. of 
Capella. 

11" 25™. = 4th mag.; yellow 
with streamers ; from 57 
Cygni, between y and ? 
Draconis, and then between 
j3 and double star v 1 and v 2 
Draconis. 


Highfield Ho., 
Nottingham. 

Ibid 


E. J. Lowe, Esq. 
Id 


MS. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 

Ibid. 

Ibid. 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


[bid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 







24 



REPORT 1849. 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1849. 










Aug. 3 


10''.= V-; pale ; from x Cassio- 


Highfield Ho., 


A. S. H. Lowe, 


MS. 




peia; to j3 Persei. 


Nottingham. 


Esq. 




6 


10" 30". = 1st mag. ; long train ; 
rapid ; from a Aquite to a 
Ophiuchi. 


Ibid 


E. J. Lowe, Esq. 


Ibid. 




S" 35"" P.M. (twilight). A bright 


Rosehill, near 


Rev. J. Slatter... 


MS. Letter. 




meteor =5 or 6 times Vega; 


Oxford, 




Appendix, No. 




estimated to fall from near 






13. 




S Cygni to 5°W. of |3 Aquarii ; 










there extinguished, leaving 










sparks.which vanished a little 










below the same point. 










lO" 45". = 2nd mag., from near 


Oxford 


Prof. Powell. 






Polaris, in the direction ol 










S Urs. Maj. ; lost behind 










buildings. 








7 


9'' 30"'. A globe meteor = J^ ; 
purple ; no train or sparks ; 
slow ; from ? Cygni through 
/ and ff Pegasi ; several 
small. 


Highfield Ho., 
Nottingham. 


E. J. Lowe, Esq. 


MS. 


8 


9^ 20'". = 1st mag.; blue ; rapid, 
with sparks ; from j3 Persei to 


Ibid 


Mrs. Lowe 


Ibid. 












y Trianguli. 










9'' 52"". Small ; yellow ; rapid ; 


Ibid 


E. J. Lowe, Esq. 


Ibid. 




from close above x Lyrre to ^ 










Herculis,leavingaline of light. 










9" 57-". Small ; yellow, with 
sparks ; swift ; from e Cassio- 


Iljid 


Id 


Ibid. 












peia to H 4 Camelopardalis. 










10'' 16". A splendid meteor, 
> 2 X 1st mag.; orange- 


Ibid 


Id 


Appendix, No. 14. 








red, with a train of sparks 










and conical head ; slow ; 










horizontally ; from K Bootis, 










passing 1° below Arcturus ; 










disappeared for about 1 sec. 










then continued in same track 










for about 1^°. 










10" 19"". = 2nd mag.; orange- 
red ; no tail ; rapid ; from 30' 


Ibid 


Id 


Ibid. 








( 




above a Urs, Maj. through 










y Urs. Maj. 










10" 27"'. Small ; rapid ; from 
56 Cygni to 11 Vulpeculae. 


Ibid 


Id 


Ibid. 








9'' 20" P.M. Small; no train; 


CastleDoning- 


W. H. Leeson, 


Communicated by j 




rather slow ; from ^ Lyrae to 


tou, Leices- 


Esq. 


Mr. Lowe. ] 




109 Herculis. 


tershire. 








gh 2l"». Very bright, and much 
larger than a Lyrae ; from 


Lat. 52° 51' 


Id 


Ibid. 




23"75 N., 








near the small star p Tauri 


Long. 1° 18' 




J 




Ponictowski to 17 Lyra; ; 


42" W. 




1 




train remained visible about 






fl 




2i sees. 










9'' 25"". Small ; slow ; no train ; 
from 106 Herculis to a Lyra;. 


Ibid 


Id 


Ibid. 






9 


12'' 0"". Yellow ;= 2nd mag.; 
very rapid ; no tail ; from H 
15 Urs. Maj. to ^P Urs. Maj. 


Highfield Ho., 
Nottingham. 


E. J. Lowe, Esq. 


MS. 




From 9'' to 1 1". Six small me- 


Gosport 


H. Burney, Esq. 


Communicated by 




teors ; direction S. and S.W. 






Mr. Lowe. 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 25 



Date. 


Description, 


Place. 


Observer. 


Reference. 


1849. 
Aug. 10 


From 9'' to IC-. Five sraal 
meteors ; two with trains 
towards S. and W. 
Till ll"" 30"". Entirely cloudy 
clear later in the night ; somf 
meteors reported. 
Cloudy till 9'' 40", thence tc 

9^ 55" ; about 10 meteors, 
gh 56". =2nd mag.; pale-red 
with stream of light ; brightes 
at centre, and fading awaj 
towards its two extremities 
rapid ; from ? Cygni to ■x 
Draconis. 
9''58°'. Similar, but fainter 

in same track. 
9!= 55"". = 1st mag.; well-de- 
fined disc ; no tail ; rapid 
from a Andromedae to « 
Pegasi. 
IC" O". Similar; fainter; in 

same track. 
IC- 2". Yellow, with tail ; very 
rapid; from s Cephei to a 
Cygni. 
10'' 3".= ? atbrightest ; yellow, 
with streamers ; brightest in 
the middle ; slow ; from x 
Antinoi through k Antinoi to 
about X Sagittarii. 
10" 4°'. Nearly similar ; in same 

track. 
lO*" 5" 30^ = ? at present ; 
globe meteor ; very rapid ; 
from 6 Aquilse to \ Antinoi. 
After disappearance a pale- 
red ray of light along the 
last 7° of the track ; lasted 
31 seconds. 
10'' 6™. Small; in same track. 
lO* 7"". Small ; yellow ; rapid ; 
from Delphinusto 69 Antinoi. 
10'' 7°. Small; yellow; rapid; 
from ff Pegasi to a little south 
of a Aquarii. 
I Oh 7m 30^ Small; in same 

track. 
10'' 8"'.= lA ; pale red ; rapid ; 
from X Delphini to 6 Antinoi. 
Continued ray lasted 2 sees, 
after disappearance. 
[0'> 8" 30^ Small ; in same 

track. 
[0'' 9-". Small ; yellow; rapid ; 
from a Cygni through t 
Cygni. 
0'' g-" 15'. = n ; pale blue ; 
defined disc ; rapid ; from 
between « and y Cygni to 1° 
S. of 1 Delphini ; stream of 
light 1' after disappearance. 


IGosport 

; Oxford 


H. Bumey, Esq. 

E.J. Lowe, Esq. 
Mrs. Lowe, A 
Lowe, Esq., A 
S. H. Lowe, 
Esq., F. E. 
Swann, Esq., 
and an Assist- 
ant. 

Id 


. Communicated 
Mr. Lowe. 

MS. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 
Ibid. 

[bid. 
[bid. 

bid. 


by 


Highfield Ho. 
Nottingham 

Ibid 


Ibid 


Id 


Ibid 


Id. ..., 

Id 


Ibid 


Ibid 

Ibid 


Id 




Id 




Ibid 


Id 




Ibid 


Id 




Ibid 


Id 




Ibid 


Id 




Ibid 


Id 




Ibid 


Id 




[bid 


d 




bid 1 


d 




bid 1 


d ] 









26 



REPORT — 1849. 



Date. 



1849. 
Aug. 10 . 



Description. 



lO*" 11'". Globe nieteor= ? at 
present ; deep blue ; slow : 
from 1° below Polaris tg a. 
Draconis ; disappeared sud- 
denly, not breaking up into 
fragments ; blue streak 10° 
in length ; lasted 4 sees, after 
disappearance. 

10" 11'" 15'. = %; pale red ; 
parallel to last ; about •^° 
below. 

10" 13°'. = 1st mag.; yellow; 
ra])id ; from midway be- 
tween a Androraedse and a. 
Peyasi to y Piscis. Streak 
along whole path ; lasted 
I sec. after disappearance. 

lO" 14"'. Small; in same track 

10" 16". = 1st mag. ; blue ; 
rapid ; from the Galaxy 
near Cygnus, ^° below Vega 
to X J-'yae ; ray visible 2 
sees, after disappearance. 

10" 17'". Small; ^Tith tail; 
rapid ; from near /3 to about 
S Pegasi. 

10" 17"" 15'. Similar; in same 
track. 

10" 17'" 30'. Do. do 

10" 19'".= lstmag. ;red ;rapid; 
from 2° N. of Arcturus, 
through 42 Coma Berenicis. 

10" 20'". Small ; rapid ; from p 
to g Pegasi. 

10" 22'" 30'. = 2nd mag.; yel- 
low ; tail ; rapid ; from 9 An- 
tinoi downwards, inclining S 

10" 23'" 30'. = 2/. ; tail ; slow : 
from N. of Lyra to t Dra- 
conis. 

10'' 24'". Small ; yellow ; rapid 
from Polaris towards Vega. 

lO"" 24'" 30'. Small ; rapid ; from 
Corona Borealis to x Ser- 
pentis. 

10" 25"". Small; tail; rapid: 
from 7 througli <t Aquarii. 

10" 25"" 30'. = 1st mag.;yellow; 
rapid ; from h Cassiopeije to 
Polaris ; ray visible 1 sec 

10" 26'" 30'. Small; rapid; 
from \ to 9 Pegasi. 

10" 28"". Small ; rapid ; from 
No. 3 Aquarii through i 
Capricorni. 

10" 30"'. Two; very small 
followed each other rapidly 
from Cygnus to Lyra. 

10" 31"".= 1st mag.; yellow; 
rapid, and with tail ; from x 
Andromeda; to \ Pegasi. 



Place. 



Highfield Ho. 
Nottingham, 



Ibid., 
Ibid.. 



Ibid., 
Ibid., 



bid. 



Ibid., 



Ibid., 
Ibid.. 



Ibid.. 
Ibid.. 

Ibid.. 

Ibid., 
[bid.. 

Ibid.. 
Ibid.. 

Ibid. 
Ibid.. 

Ibid.. 

Ibid.. 



E. J. Lowe, Esq. 
&c. &c. 



Observer. 



Reference. 



MS. 



Id. 



Ibid. 
Ibid. 



Ibid. 
Ibid. 



Ibid. 



Ibid. 



Ibid. 
Ibid. 



Ibid. 
Ibid. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 2f 



Date. 



Description. 



1849. 
;. 10.. 



IC 34™. = 1st mag.; rapid; 
from a Cygni to /3 Lyr» ; 
continuous white ray, 1 sec 
after disappearance. 

10'' 34'" 30'. Smaller, but 
Biniilar ; from \ Cygni to a 
Herculis. 

10'' 35"'. Small; rapid, down 
wards from y Cassiopeise. 

lOi" 35"° 30'. = li- ; blue ; de 
fined disc; brilliant; from 
27 Urs. Maj. to 0° 34' above 
a Urs. Maj. ; blue continuous 
streak. 

10'' 36"'. Small ; yellow ; rapid ; 
from y Cassiopeiae to ij 
Persei. 

10'' 36" 30'. Small ; rapid ; 
from H 32 Camelopardalis 
to 7 Draconis. 

lO* 38'". Small; rapid; from 
81 Urs. Maj. to \ Bootis. 

10'' 38" 30'. Similar ; in same 
track. 

lO*" 40". Small ; rapid ; from H 
43 Cephei to H 32 Camelo 
pardalis ; ray of light. 

10'' 44"'. Small ; rapid ; from x 
Corona Borealis to d Bootis 

10'' 44" 30'.= ? at brightest; 
pale yellow ; rapid ; from 
Andromedae to between 
and jS Trianguli ; ray visible 
1 sec. after disappearance 

10'' 45". = 1st mag. ; yellow; 
rapid ; from 3 Urs Min. to 
C.H.122Urs.Maj.; left train. 

10'' 45" 30'.= ^ at brightest 
yellow ; rapid ; from /3Andro- 
medae through ip Piscis 

10'' 40". Small ; rapid ; from 
just above r downwards, in 
clining to S. 

10'' 4 7'". Small; rapid; from 
nebula in Androm., just 
above u to 17 Andromedae, 

IQk 49"'. Small ; rapid ; from y 
Urs. Min. to rj Draconis. 

lOi" 50" 30'. Small ; rapid; from 
X Cassiop to h Cassiop. 

lO"" 52". = ? ; red ; defined 
disc ; slow ; from e Persei 
downwards ; no train ; after 
this cloud)'. 

Between 9'' 30" and 9'" 33" p.m 
A rather large meteor, from 
between Cygnus and Cassio 
peia, to between Cygnus and 
Pegasus ; left reddish train of 
sparks ; brightest at mid. part. 



Place. 



Highfield Ho., 
Nottingham. 



Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid 

Ibid ,. 

Ibid 

Ibid 

Ibid 



[Loi)don 
BetbnalGreen, 



Observer. 



E. J. Lowe, Esq. 
&c. &c. 



Id 

Id, 
Id 



Id 

Id 

Id 

Id. 

Id. 

Id. .......... 

Id 



W. R. Birt, Esq 



Reference. 



MS. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 
IbifJ. 



Ibid. 
Ibid. 
Ibid. 

Ibid. 
Ibid, 

Ibid. 

Ibid. 

Ibid, 

Ibid. 

Ibid. 
I})id. 
Ibid. 

Appendix, No. IB. 



28 



REPORT — 1849. 



Date. 

1849. 
Aug. 10 . 



Description. 



Small meteor, from 1° or 2° E. 

of Polaris, downwards. 
Small ; rapid ; very obliquely 
across the line joining a and 
/3 Pegasi. 
Small ; near head of Capricorn ; 

direction S.W. 
gi'SS™ (?) Rather large; from N 
of Cassiopeia to a little N. of 
Cygnus ; train of reddish 
sparks ; brightest at mid. part, 
1 0*" 5" (?) Very large and bright ; 
from below Ursa Major to S 
of Corona Borealis; reddish 
train. 

— Small, but bright ; through 
Polaris. 

— Globular meteor = % ; red- 
dish; slow; through y Pegasi; 
increased in brightness. 
— Another, exactly similar, 
after about one minute, in 
prolongation of same path. 
From 9" 19'" to lOh 33", fifty- 
five shooting stars were ob- 
served in such rapid suc- 
cession that it was found im- 
possible to note the exact 
positions of the whole of 
them. Occasionally they 
much resembled a shower of 
rockets, shooting in all pos- 
sible directions. The follow 
ing are the chief : — 
911 55'". = Altair; very brilliant 
rather slow ; from y Aquilse 
to a. Delphini ; train visible 
2 seconds. 
IC l". Somewhat quicker ; no 
train ; from ff Herculis to a 
little above jj Lyrae. 
IC 10™. Two together; one 
much brighter than the 
other; moved uniformly down 
the Milky Way from £ Cygni 
to a and y Sagittae ; the 
brighter appeared to ter^ 
minate its course in a zigzag 
form, leaving a small train ; 
the other none. 
10'' 11"". Very brilliant ;>lst 
mag. ; from Polaris to x Ser 
pentis ; train visible 3 sees, 
rapid ; bluish white ; cast a 
visible shadow. 
10'' 12"". Brighter than 1st 
mag. ; rather slow ; from 
Deneb to a. Lyrae. 
10'' 15"". Bright; straw-colour; 
rather slow ; from Deneb to 
X, Lyrae. 



BethnalGreen, 

London. 
Ibid 



Place. 



\V. R. Birt, Esq. 
Id 



Ibid., 
Ibid. 



Ibid. 



Ibid., 
Ibid., 



Ibid. 



CastleDoning- W. H. Leeson, 
ton, Leices- Esq. 
tershire, lat. 
52° 51' 
23"-75 N. ; 
long. 1° 18' 
42" W. 



Observer. 



Id. 



Id. 



Id. 



Id. 



Ibid., 



Ibid. 



Ibid., 



Ibid., 



Ibid. 



Ibid., 



Reference. 



Appendix, No. 18. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 



Communicated by 
Mr. Lowe. 



Id. 



Id. 



Id. 



Ibid. 

Ibid. 
Ibid. 



Id. 



Id. 



Ibid. 



Ibid. 
Ibid. 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 29 


Date. 


Description. 


Place. 


Observer. 


Reference. 


1849. 
Aug. 10 

11 

12 


IC" 21™. Brilliant ; from Deneb 
to Aldebaran. 

lOh 23'". Two togethef; one 
from near y Cygni to tt" 
Cygni, crossed the path of 
the other at riglit angles, 
justbelowDeneb ; both=2nd 
mag. ; slow. 

lOk 24"". A stream of meteors 
in parallel lines ; from y 
Cephei to /SCassiopeise, about 
30' apart ; slow. 

10'' 26™. Very light; seen 
through thin clouds ; down 
the Milky Way from Deneb 
to midway between ;8 Cygni 
and 6 Vulpeculse ; train 
visible 3 sees. 

lO'' 30™. = 3rd mag. ; no train ; 
from /3 Cassiopeiae to Schedri. 

lOi'Sl™. Very brilliant; from 
? Cygni to $ Lyrse; train 
visible through thin clouds. 

lO*" 33™. Large, but obscured 
by clouds, from ^° beyond 
Polaris to y Urs. Min. 
After this cloudy. 


CastleDoning- 

ton, &c. &c. 

Ibid 


W. H. Leeson, 

Esq. 
Id 


Communicated by 

Mr. Lowe. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 

Ibid. 

Ibid. 
MS. 

Ibid. 

MS. 

Ibid. 

Ibid. 
Ibid. 

Ibid. 
Ibid. 
Ibid. * 

Ibid. 


Ibid 


Id 


Ibid 


Id 


Ibid 

Ibid 


Id 


Id 


Ibid 


Id 


Ibid. ... 


Id 


lO*". = 1st mag. ; yellow ; rapid ; 

from T Pegasi to about 1° 

above, and thence to 5 Pegasi; 

left streak, 
ll"" l™. = 2nd mag.; yellow; 

tail ; rapid ; from y Sagittse 

through y Aquilae to between 

a and /n Aquilae. Much vivid 

lightning in S. 
Cloudy ; coruscations over N. 

and W. horizon. 
lO"- 9™. Small ; from Via Lactea 

close to Delphinus, upwards 

to a Cygni. 
10'' 10™. = 2nd mag.; yellow; 

rapid ; tail ; from ? Pegasi to 

y Aquarii. 
10'> 13™. Small; from Corona 

Borealis to \ Serpentis. 
IQh 14"'.= 1st mag. ; yellow; 

tail ; rapid ; from a Dra- 

conis to \ Corona Borealis. 
lO* 16™. Small; from g Dra- 

conis to T Corona BoreaUs. 
10*' 20™. Small ; rapid ; from 76 

Urs. Maj. through X Bootis. 
IQk 21™. =lstmag. ; yellow; 

no tail ; rapid ; from Vega 

through 110 and 111 Her- 

culis. 
lO"- 22™. Small ; rapid ; no tail ; 

from X Urs. Majoris to 

Arctm-us. 


Highfield Ho., 
Nottingham. 

Ibid 


E. J. Lowe, Esq. 
Id 


Oxford 


Prof. Powell. 
E. J. Lowe, Esq. 

Id 


Highfield Ho., 
Nottingham. 

Ibid 


Ibid 


Id 


Ibid 


Id 


Ibid 


Id 


Ibid. 


Id 


Ibid ... 


Id 


Ibid 


Id 

















30 



REPORT — 1849. 



Date. 


Description. 


Place. 


Observer. 


Reference. 

1 
.. 


1849. 
Aug. 12 1 


O*- 23™. Small ; rapid ; from 


Highfield Ho., E. J. Lowe, Esq. MS. 


H ISUrs.Maj. through 66 and 


Nottingham. 








3 Urs. Mai. 








lO"" 23'". =' h ; blue; rapid;] 
from f Cassiopeia to H 18 


bid I 


i. H. S. Lowe, Ibid. 
Esq. 






Camelopardal.s; blue streak ; 










visible for 5 sees. 










lO"" 23'". = 1st mag. ; yellow ; 
rapid ; from /3 to ? Pegasi. 


bid Id \. 


bid. 








lO*" 36'". Small ; rapid ; from 


[bid 


K. J. Lowe, Esq. 


bid. 




28 and C.II. 153 Urs. Maj. 










to V Urs. Maj. 










LC 38™. Small ; rapid ; from Z 
to y Urs. Maj. 


Ijiij 


[d 


[bid. 








10'' 38'". Small ; from S Urs. 
Maj. through 11 Canium 


H)i(l 


[d 


[bid. 








Venat. 










These two crossed each "I 










other's paths about 1° ■ 










above No. 1 Can. Venet. J 










lO"* 42'". Small ; rapid ; from 
7- Herculis to jS Bootis. 


Ibid 


Id 


Ibid. i 












10'' 46". Small; yellow; tail; 
rapid; from C.H. 155 Came- 


[bid 


Id 


Ibid. 








lo, ardahs to Capella. 










IC 46"" 30'. Small ; rapid ; from 
/} Hercidis to jS Bootis. 


Ibid 


Id 


Ibid. 1 












lO"" 47". Small; rapid; from 
Corona Borealis to y Ser- 


Ibid 


Id 


Ibid. i 








1 




pentis. 










10'' 56'". = V ; red ; rapid ; 
from \ to 31 Pegasi; left ray 


Ibid 


Id 


Ibid. 












visible 3 sees. 










lliil'". Small; rapid; from y 
Urs. Min. horizontally to 7] 


Ibid 


Id 


Ibid. !, 








Draconis. 










11'' 5'". Small, with streamers- 
rapid ; from 31 to 3° beyond 


Ibid 


Id 


Ibid. 








36 Pegasi. 










28 meteors, of which 21 


Castle Do- 


W. H. Leeson, 


Communicated by 




proceeded from points in 


nington. 


Esq. 


Mr. Lowe. 




or near Cygnus, and 7 from 










Ursa Minor. Only 1 brilliant 










from Deneb to a. Lyrae ; train 






; 




visible 3 sees. 






Ibid. 




From gt" 30"" to 10^ 30'". Sever 


Gosport 


H. Bumey, Esq. 




meteors ; 3 between Cygnus 










and Delpbinus 1 large, fron- 










Corona Borealis to a Her 










culis ; another from Aquila 


; 








gold colour ; direction at firs 


t 








S., then S.W., givhig a zig 








13 


zag path. 
From 9'' to ll*". Four meteors 
The first passed betwee 


Ibid 


Id 


Ibid. 


1 








Polaris and the Guards o 


f 








Urs. Min. ; one under an 


I 








one tl rough the tail of Urs 






[ 




Maj., and the other tw 







1 




over Lyrae. 









A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 31 



Date. 


Description. 


Place. 


Observer. 


Reference. 


1849. 










Aug. 13 


Brightness = ju Andromedse 
with slight train ; movec 


Grantham ... 


J.W. Jeaps, Esq. 


Communicated by 
Mr. Lowe. 




about 8° in 1 sec. ; parallel 
to a line joining |8 with [i 
AndromediE ; disappearec 
very close to, and N. of /; 
Andromeda, at 20'' 17" 8'-08 
sidereal time, or 10'' 47"" 58' 
Grantham mean time, taken 
from culminating of a" Ca- 
pricorni. 








16 


10" 40'". Bright, with train 
passed over the square o: 
Pegasus. 


Gosport 


H. Burney, Esq.. 


Ibid. 




Three small, between g"" & ll*" 
10'' 10"".= (7 ; red; tail; rapid 


jljjj 


Id 


Ibid. 
Ibid. 


HighfieidHoV, 


A. S. H. Lowe, 




from X Draconis to e Urs 
Maj. 
10'' 37"°. = 2nd mag.; from 
Draco to a little above Cor 


Nottingham. 


Esq. 






Oxford 


Prof. Powell. 








Borealis. 








i 


lOi" 37'". = 2x]st mag.; red 


Highfield Ho., 


E. J. Lowe, Esq. 


Ibid. 




train of sparks ; slow ; from I: 


Nottingham. 








27 Ophiuchi to 52 Serpentis 










train lasted 2 sees, after dis- 










appearance. 










lO*- 45'". Small.with tail ; rapid 
from Vega to W. Herculis. 


Ibid 


Id 


Ibid. 












lO"" 55'". = 2nd mag.; rapid 
from a Aquilae to x Antinoi. 


Ibid 


Id 


Ibid. 












10'' 55™. About ten fallirfg^ 
stars, exceedingly dimi- 


Ibid 


Id i. 


Ibid. 








nutive, but very brilliant 










for their size, which was 










scarcely =6th mag. This 










gave the impression of 










their being fine meteors. 










hut at a very great 










height. 










One passed near Polaris, 










another in the Great }■ 
Bear, and one in the 


Ibid 


Id 


Ibid. 








Little Bear. All towards 








1 


theW. 










Several in Pegasus, Serpens, 










Ophiuchus, and Hercu- 










lis ; moved towards the S. 










Probably they all moved 










S.W. if they could have 










been seen without the 
effect of perspective. 
















23. 


10'' 28'". = 2nd mag.; orange 
red, with streamers ; rathei 


Ihid 


Id 


MS. 








rapid ; from r to o- AquiUe. 








26 


10'' 28". Small; yellow, wit! 
streamers ; rapid ; from jc 


Ibid 


Id 


Ibid, 








Delphini to r Aquilae. 














• 


• 



32 REPORT — 1849. 

APPENDIX. 

Containing details from the original Records of Observations, communicated 
to Professor Powell by the respective Authors, referred to in the foregoing 
Catalogue. 

No. 1. — Fall of Meteorites at Stannern, near Blatisko, Moravia, Nov. 25, 
1833. Note from W. W. S-MYTH, Esq. 

1. On the evening in question, the appearance of a brilliantly luminous 
meteor was accompanied by a loud report like that of a cannon, followed by 
a sound like the fire of musketry. M. Reichenbach obtained information 
from various quarters as to the angle under which the meteor was seen, and 
then searched diligently with sixty or seventy men for what they supposed 
must have fallen, till on the 1 1 th day they discovered a meteorite, and after- 
wards two smaller stones. Their external colour was black, the internal gray ; 
the structure granular and full of metallic specks : they also attracted the 
magnetic needle. 

2. A meteorite which fell near Stannern in May 1808, was analysed by 
Von Holger, and was found to contain, though in very small quantity, tin 
and cerium, which had not before been discovered in similar bodies. The 
result of five analyses was as follows : — 

Silica 0-488 

Protoxide of iron 0*280 

Alumina 0-039 

Manganese 0-085 

Lime 0-068 

Magnesia 0-027 

0-987 
The formula for the whole is 7fS2 + 2Al S2 + 2mg S«+MS*+2C S« 

for the gray constituent (7f+2mg)S'^ 

for the white (2Al + M + 2C)S2 

Baumgartner, Zeitschrift fiir Physik, 1834, and Leonhard and Bronn, 
Jahrbuch, 1836, p. 497. 

No. 2. — Meteorite of Braunau. Note from W. W. Smyth, Esq. 

M. Beinert of Charlottenbrunn, read before the Breslau Society an ac- 
count of the fall of meteorites at Braunau in Bohemia, and exhibited plans 
of the locality and a portion of the iron. — Schles. Arbeit. 1847. 

On the 14th of July, at a quarter to four a.m., the inhabitants of Braunau 
were roused by two violent explosions like heavy artillery, and as closely 
consecutive as the reports of a doubled-barreled gun, after which a rushing 
and hissing sound was audible for some minutes. The sky was very clear ; 
but above the village of Hauptmannsdorf there was formed a small strip of 
black cloud, which suddenly seemed to grow red-hot and to dart out flashes 
of lightning in all directions, whilst at the same moment two fiery streaks 
seemed to fall to the earth. The cloud now assumed an ash-gray colour 
and rosette form, and after some time divided towards the N.E. and S.W., 
forming thin streaks which gradually disappeared. 

It was soon found that the " lightning" had struck the ground near Haupt- 
mannsdorf, about 1200 paces N.E. of Braunau, and there in a hole three feet 
in depth was a mass of iron which at ten a.m. was too hot to be touched with 
impunity. One Joseph Tepper, living in the village, had seen it fall, and 
gave his evidence on the subject before the authorities of Braunau. This 



A CATALOGUE OF OBSERVATIONS OP LUMINOUS METEORS. 33 

piece of meteoric iron, weighing 42 lbs. 3 oz. Austrian, was sent to the Imperial 
Cabinet at Vienna. Its form is an irregular parallelepiped, and the exterior 
surface is covered with concavities, the deeper parts of which exhibit a smooth 
yellowish brown coating. 

It was soon afterwards found that the "lightning" had penetrated the do- 
minial house called the Ziegelschlag, situated at a short distance from the 
town. Mr. Pollack, the chief forester, describes that he found a hole as large 
as the head in the roof, and a mass of broken lath and plaster in the bed-room 
of three children, who, when terrified by the crash, were unable to escape. 
The piece of iron which was found here under the ruins, weighed 30 lbs. 8 oz., 
and diflPered from the other only in form, inasmuch as it has some resemblance 
to a colossal oyster-shell. In breaking through the plaster, the melted sur- 
face carried off some unconsumed straw, which gives it at a distance a gold- 
like appearance. The chief forester Pollack calculated the height of the 
cloud from which the two fragments diverged at 29,351 Vienna feet=29,562 
Prussian feet* ; the distance asunder of the two places where they fell being 
6507 Vienna feet. 

Analysis of the Braunau meteoric iron, by A. Duflos and N. W. Fischer. 

Iron 91-882 

Nickel 5-517 

Cobalt 0-529 

Copper ~ 

Manganese 

Arsenic 

Calcium 

Magnesium ^ 2-072 

Siliciura 

Carbon 

Chlorine 

Sulphur J 

100-000 
It was afterwards found that the mass was not homogeneous, but contained 
portions of iron pyrites, in which Fischer found also carbon, phosphorus and 
chromium. — Poggendorff's Ann. Ixxii. 

Extract from a letter from W. W. Smyth, Esq. 

" London, March 1, 1849. 
"I have just met with a curious fact, viz. the presence o{ phosphorus in 
certain meteoric irons. 

" Berzelius found in the meteoric iron of Bohumilitz certain steel-gray lami- 
nettes and grains, which he proved to be composed of iron, nickel and phos- 
phorus. Lately, my friend Patera at A'^ienna has analysed a similar mineral 
in the meteoric iron of Arva. It was observed in small leaflets, which are 
flexible, and have a strong eflTect on the needle ; the hardness=6*5, the spec. 
gr.=7-01 to 7-22, and the composition — 

Phosphorus 7*26 

Iron 87-20 

Nickel 4-24. 



98-70 
"The mean of three analyses also gave a small quantity of carbon. The 
name Schreibersite has been proposed for this new mineral. 

" Yours ever, 

" Wabington W. Smyth." 

* Above 30,000 English feet, or five miles and five fiirlongs. 
1849. D 



34 REPORT — 1849. 

No. 3. — Letter from Dr. Buist to Professor Baden Powell, Oxford. 

" Bombay, July 22, 1849. 

" Dear Sir, — I now enclose some notices of those meteors of lesser magni- 
tude and greater frequency noticed at Aden, by Mr. Moyes in 1843, and by 
my assistants wliile in charge of the observatory here, in 1843 and 1844. 

" I am at present in communication with observers at thirty different stations 
scattered over India, from latitude 10° to 33°, and am making arrangements to 
get returns from every spot where an European is stationed in the service of 
government. By these means, I shall, 1 hope, have it in my power to furnish 
you with a long and minute catalogue of meteors every year. Careful simul- 
taneous observations along chains of stations will soon come to give us the 
relation of diiferent meteors to the stars and constellations they seem to ap- 
proach or traverse, and furnish us with the elements of computing their size 
and distance. The newspapers I have already sent will have given you all 
the information I possess in reference to the larger meteors; in the " Times" 
now forwarded, is a description of one seen at Kurrachee on the 25th of June 
(our sky at this season is covered with clouds), which, like that of the 19th 
of March, was heard to explode. 

" The leading characteristics which distinguish our larger and lesser aero- 
lites are the following : — the larger generally appear as luminous as a star of 
the first, the lesser scarcely so much as a star of the third magnitude. 

" The light of the larger meteors is generally orange, bluish or greenish, 
hardly ever white. It resembles that of a star of a Roman candle, as if given 
out by a considerable mass of matter : it never exhibits rays like a fixed star 
or the light from electricity ; it is never at all dazzling. The meteor always 
seems to increase in velocity and bulk as it proceeds in its path, the result 
probably of perspective ; and when approaching the termination of its course, 
it commonly flames out witii unusual brilliancy ; there are about as many 
■which disappear at once, as if extinguished, as those which burst and fall in 
fragments. The fragments always cease to be visible at some 5° to \b° from 
the ground. The only meteors that have been heard to explode this season 
were those of the 19th of March, heard at Aurungabad, and 25th of June, 
heard at Kurrachee. 

" From the 1st of June to the 1st of September our sky is thick and cloudy. 

" If meteors fall over the twenty-four hours indiscriminately, the number 
entering our atmosphere must be immense. They are not visible till after 
sunset, and by eight or nine o'clock we are all indoors, by ten we are in bed ; 
two hours thus is all the time allowed for observation. We expect to derive 
the greatest advantages from the services of European sentries on duty, as 
we are now striving, with every hope of success, to engage the army in our 
service. 

" Our November meteors cross the sky in all directions : they very much 
resemble fire-flies, only they are much more swift and rectilineal in their 
movements. They do not alter either in apparent speed or size as they pro- 
ceed ; they never flame out or appear to burst ; they very rarely approach the 
horizon, and having traversed ten or twenty degrees of space, become lost in 
darkness. " I ever am, 

" Most faithfully yours, 

" George Buist." 

No. 4. — From the Bombay Times, November 1, 1847. 

" On the 7th of September, about half-past six p.m., a large fire-ball was 
seen at Poona to shoot from nearly north to south : it then made a sudden 
sweep, and proceeded nearly at right angles to its previous path. After being 
visible for five or six seconds, it split into a number of large fragments, which 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 35 

rapidly descended towards the earth ; and tliese again broke up into lesser 
fragments, till they appeared to descend in a shower of sparks. Before the 
first bursting, the meteor was of exceeding brightness, of an intense blue co- 
lour, and at the instant of explosion it changed into red : — it seemed to light 
up the whole heavens, though the moon was shining, so as to render the lesser 
stars visible." 

From the Bombay Times, November 1, 1847. 

" On Sunday evening (Oct. 30), about seven o'clock, a magnificent 
fire-ball was seen to shoot across the air from nearly west to east, when its 
horizontal motion suddenly ceased and it seemed to drop perpendicularly 
into the sea betwixt Mazagon and Sewree. At the time of its explosion — 
for such we may take that of its change of direction to have been — its 
illuminating power was equivalent to that of an ordinary- sized blue light : 
it dazzled the eyes of those near it and who looked at it directly ; and though 
the evening was at the time perfectly dark, the most minute objects in the 
landscape were for ten or fifteen minutes made visible by it. It appeared to 
become extinguished some three or four hundred feet before touching the 
water. It left a long train of light behind it, which was visible for the space 
of nearly half a minute." 

No. 5. — From the Bombay Monthly Times, June 18, 1848. 

" At a meeting of the Bombay Geographical Society, the following letter 
was received from Captain George Wingate, of the Bombay Engineers : — 
. " ' I beg to transmit two fragments of an aerolite, which fell about one o'clock 
P.M. of the 15th of February last, 1848, in a field to the south of Negloor, a 
village situated within a few miles of the junction of the Wurda and Toom- 
boodra rivers, and belonging to the Gootul division of the Ranee-Bednoor 
talook of the Dharwar coUectorate. 

" ' The fall of this aerolite is most satisfactorily established. A cultivator 
of Negloor, named Ninga, was driving his cattle out to graze close by where 
it fell, at the hour above mentioned, when he suddenly heard a loud whirring 
rushing noise in the air, but on looking up could see nothing. An instant 
afterwards, however, he observed a cloud of dust rise from a spot in an ad- 
joining field, as if something had struck the ground there with violence. At 
this time several other villagers were standing by a threshing-floor close at 
hand, who also heard the noise, and one of them called out to Ninga asking 
whether he had also done so. He replied. Yes, and that something seemed 
to have fallen in the next field, where he saw the dust rise, pointing at the 
same time to the spot. The whole party then immediately proceeded there, 
and found to their astonishment the aerolite broken into fragments, of which 
those now forwarded were alone of any considerable size. The stone, from 
the velocity of its descent, had made a hole of several inches in depth, — like 
the print of the foot of a young elephant, as the villagers described it. They 
were naturally much puzzled to account for the appearance of the stone, which 
altogether differed from any to be met with in their neighbourhood ; but at 
length were constrained to conclude it had fallen from the sky. The cir- 
cumstance seemed so extraoi-dinary that one of them was immediately sent to 
summon the Patel of the village to the spot, who soon arrived, attended by a 
crowd of people who had also heard the wonderful tidings. These too una- 
nimously adopted the same conclusion regarding the fall of the stone, and the 
Patel took into his charge the accompanying fragments, and wrote a report 
of the whole circumstances to the Mahalkurree of Gootul, who is revenue and 
police officer of the district in which Negloor is situated. 

D 2 



36 REPORT — 1849. 

" ' The Mahalkurree thought the Patel's report so extraordinary that he de- 
termined at once to proceed to Negloor himself, to inquire as to its truth, 
which he did ; and after having examined the stone itself, as well as the 
hole in the ground made by its fall, and found all the accounts of the villagers 
who were present to agree, he could not avoid coming to the same conclusion 
that they did, regarding its fall from the sky. To place the matter beyond 
doubt, however, he took statements in writing of the circumstances from the 
cultivator Ninga and another, who had heard the rushing noise made by the 
stone in its passage through the air, and forwarded their depositions, with 
his own report and the fragments of the aerolite, to Mr. Goldfinch, the assist- 
ant collector and magistrate in charge of the district, who has kindly placed 
them at my disposal. 

" ' Had the evidence in proof of the fall of this stone been less conclusive 
than it is, we might still have inferred the fact of its being an aerolite from its 
peculiar appearance, so different from that of any rock in the neighbourhood 
of the spot where it was found. For miles around the village of Negloor, the 
only rocks to be found are primary clay-slate of various degrees of induration, 
and occasional dykes, masses and boulders of greenstone, but not a trace of 
any volcanic product, or other ftone bearing the remotest resemblance to the 
one under consideration. The latter, moreover, tallies exactly with the de- 
scriptions given of aerolites. It is coated with the fused crust or film charac- 
teristic of these bodies, and is evidently highly metallic. On the theory of 
aerolites being planetary bodies which become fused on their surfaces, and 
burst by the sudden evolution of heat occasioned by their rushing at immense 
velocities into our atmosphere, the specimen now forwarded may be supposed 
to have formed part of a globe, or rather a mass approaching the spherical 
shape, of somewhat more than a foot in diameter, which burst into fragments 
under these circumstances; and the difference in appearance of the position 
of the fused film over the rounded part of the specimen, which may be con- 
sidered to be a portion of the surface of the original globe, and of that coating 
the remaining parts, which according to this view were the rough broken 
surfaces of the detached fragment, would seem to favour this explanation. 

" ' These remarks, however, are merely thrown out in the way of conjecture, 
as I do not pretend to any knowledge that would entitle me to theorize on 
the subject at all. My object in writing at so much length has been to show 
that the specimen now sent is a part of a true aerolite, and as such, I hope it 
will be thought worthy of a place in the new Museum.' 

" The mass of stone which accompanied this was somewhat ovoidal : it 
weighed four pounds, measuring fifteen inches round the larger, and eleven 
round the sliorter axis. It was covered over with a black-looking vitrified 
crust about one-twentieth of an inch in thickness. This refused to yield to 
the action of muriatic, nitric, or sulphuric acids. One end of it was marked 
with impressions such as a slightly softened body might receive on being 
thrown violently against the earth. The specific gravity of the crust was a 
little over three, or somewhat heavier than marble; it had not been quite 
accurately determined, from the difficulty of separating the crust from the 
interior. The interior of the aerolite was exactly like softish white sandstone ; 
it crushed between the fingers, and absorbed, when immersed an hour in 
water, one-hundredth of its weight. Its specific gravity was 3'5, or a third 
heavier than the heaviest sandstone, that of quartz being 2*6. It slightly 
effervesced with muriatic acid, giving off much sulphuretted hydrogen gas, 
and then slowly dissolved into a glutinous mass. It seemed full of metallic 
particles, which shone beautifully under a moderate magnifying power, with 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 3? 

a dull light. The following note by Dr. Giraud gives particulars of the re- 
sults of the first examination of its characters : — 

" ' The stone is acted on by cold hydrochloric acid, with disengagement 
of sulphuretted hydrogen. Boiling, but not cold, nitric acid acts on it vio- 
lently, disengaging HS and NO4. The great part of the stone is silica: the 
metallic granules consist of iron in equal proportions, with nickel and chrome — 
in fact meteoric iron. The nickel of course is much obscured by the iron : 
the chromine was readily detected, for on fusing the stone with nitre, dissol- 
ving the fluid mass in distilled water, and then testing with acetate of lead, 
a fine yellow chromate of lead was obtained. On fusing the stone with nitre, 
chromate of potash was of course produced. I cannot detect any cobalt, 
vhich you know Stenmeyer found in the mixture of iron at the Cape of Good 
Hope.' " 

No. 6. — Letter from E. J. Lowe, Esq. to Prof. Powell, enclosing one from 
Sir J. W. Herschel, &c., received July 11, 1849. 

"My dear Sir, — The following account of a meteor was sent me by Sir 
John Herschel ; I accidentally omitted to forward the account of it to you 
with my former catalogue. I may remark that it was noticed at Bath, but 
am afraid by no one capable of accurately describing it ; perhaps the insertion 
in the British Association Catalogue may be a means of obtaining further in- 
formation of this fine meteor. " Yours ever truly, 

" E. J. Lowe." 

" ' My dear Sir, — The parents of a young person residing in our family 
(of the name of Atkins) were aroused on the night of March 8th, by a noise, 
which induced Mr. A. to get up. At four a.m. he was struck with a great 
light; it emanated from a meteor larger than the moon which shot across 
above Windsor Castle as seen from Slough (two miles), i. e. looking nearly 
southwards. I can get no correct notice of the altitude above the horizon, 
which is a pity, as it seems to have been a first-rate one, and its course being 
horizontal and from west to east, must have been seen on the French coast, 
and probably by seafaring people (who watch nightly) in the Channel. I en- 
close a note of explanation from Mrs, A. to her daughter ; perhaps you may 
have some corresponding observations, in which case it will be worthwhile to 
question further about the apparent altitude as seen from Slough. 

" ' Your very faithful Servant, 

" 'J. F. W. Herschel.'" • 

Extract from a letter received by Sir John Herschel on the meteor, from 
Mrs. Atkins. 

" *0n this morning (March 8, 1848), four a.m., a large body of light in 
the shape of a kite, more brilliant and larger than the moon, passed across 
from west to east ; it moved gently ; indeed your father had time to wake me, 
and I to get up to the window before it disappeared ; the colo\ir was a strong 
blaze of fire ; it shot from the clouds and disappeared in the same. It travelled 
from the west of the Castle to the extremity of Datchet. 
The stars were shining at the time. The noise that awoke 
Mr. Atkins, had not, in his opinion, anything to do with 
the appearance. It was of this shape.'" 

No. 7. — Extract from a letter dated Pisa, Tuscany, Sept. 9th, 1848. 

". . . . Last evening, Sept. 8th, about ten minutes before seven, I observed 
from my window, facing due south, a luminous ball of fire, about the size of 
an orange, glide gently past from N.W. to S.E. The moon was up ; it passed 



38 REPORT — 1849. 

under the moon, and seemed to spend itself before it would otherwise become 
invisible from the convexity of the earth. Mrs. Irving also saw it, but I am 

not aware of any one else 

" I have the honour to be, Sir, 

" Your obedient Servant, 
" To Professor Powell, Oxford^ "James Irving." 

"No. 8. — Extract from a memorandum communicated to Prof. Powell by 
W. H. Black, Esq. of the Rolls' Office, dated Mill-yard, Whitechapel, London, 
March 6, 184.9. 

"This evening (March 6, 1849), soon after sunset, a bright meteor fell. 
It began its path somewhat below and to the southward of the ^ , and fell in 
a curve, brighter all the way than $ (which was then shining in the west), 
and exploded at the end of that curve with a flash, its body appearing of the 
colour and brightne.-s of the ([ , somewhat lanceolated, half as large as the 
([ , and slightly greenish and red in the flash with which it expired or dis- 
appeared. 

"It was about 1 second or 1^ in falling; and the time was (as nearly as I 
could ascertain by my watch and clock) IH*" 8™ C.T., or 6° 8' p.m. 

" The window from which I saw this phsenomenon looks directly eastward ; 
and as I stood on the left side of the window, I could clearly see the S.E., 
and marked the exact spot where it disappeared, as well as its path through 
the leafless boughs of a tree, the C being about 45° in height, S.E.E. ; and 
the meteor exploding about 12° or 15° in height S.E. from me." 

No. 9. — The Bombay Times, March 21,1 849, gives a statement from a cor- 
respondent, announcing the appearance of a luminous meteor at Bombay, on 
Monday, 19th March, at 6\ p.m. 

Ibid. March 24. The editor adds : — " The meteor, as seen from the 
esplanade, seemed to issue from a thin streak of cloud overhanging the dock- 
yard. It thence rushed in a north-easterly direction, as if over the custom- 
house and towards the town-hall. The light it emitted was of a brilliant 
green : when it exploded it seemed resolved into a mass of red embers. The 
meteor was seen from Poona, Tannab, and probably over a very large expanse 
in the interior, and must have been, when it exploded, very much higher in 
the air than it appeared." 

The following are extracts from correspondence subjoined : — 

" I (with others) was to the north-east of the police hulk on the evening 
in question, and saw the fire-ball, whicii appeared to rise from one of the 
ships lying nearest to Mazagon : this brilliant meteor might have been at 
any distance you please in the N.E., though we fancied that it was within 
three hundred yards of us. — F." 

"On Monday (19th) evening, as I was taking a walk with a friend of 
mine on the Grant road ' flats,' my attention was attracted to, as it were, a 
planet of the size of a common-sized hen's egg(?). A second or two did not 
elapse from the time I saw it whole-till it burst, and the light that it shed 
was unusually brilliant for a meteor. I may here mention that tve were not 
the only persons who saw it ; for on my going to the fort the next morning, 
a friend of mine told me that as he was spending the evening at Mazagon, 
he saw just what I have related. — G." 

"On Monday the 19th inst., a meteor answering the description was seen 
by a friend of mine about the same hour on that evening in a N.E. direction. 
It was first seen in the form of a ball about the size of a large egg(?), darting 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 39 

towards the earth : it broke into numerous small brilliant fragments, and 
disappeared. It was visible about half a minute. — S." 

Poona, 22nd March. 

In the same journal of March 28, further particulars are given, of which 
the following are extracts : — 

" Subjoined is a series of notices of the luminous meteor seen on the 
evening of the 19th, which now appears to have been a much more magni- 
ficent variety of aerolite than was at first supposed. It appears to have been 
at a great elevation, and, as suggested by a Poonah correspondent, was pro- 
bably some hundreds of miles from the nearest spectator when first seen. 
The volume of tire mass, the length of its course, and the velocity with which 
it rushed along, may from this be imagined. As formerly observed, when 
first seen at Bombay it appeared as if nearly over the dockyard : in this all 
the observers who noticed it in different parts of the island concur. Curi- 
ously enough, we have not been favoured with a single notice of it from any 
one on board the ships in the harbour: from the anchorage we have no doubt 
it would also appear to the eastward. At Poonah — lat. 18° 30' N., long. 72° 
2' E. — it was observed at a quarter past six at the altitude of about 30° : it 
was visible from Poorundhur, twenty-six miles east of Poona. It was ob- 
served at Aurungabad, lat. 19° 45' N., long. 75° 30' E., as if to the south; 
and from Sholapore, lat. 17° 40' N., long. 76° E., where its appearance was 
most distinctly observed, and has been most carefully described, as seen in a 
north-easterly direction. It was seen at Jaulnah, particulars not given. It 
was also carefully observed at Surat, 21° 11' N., 73° 7'E. It has thus been 
described as visible over an area of above 3° of longitude and 2° of latitude 
— from Bombay 18° 53' N., and 72° 49' E., to Sholapore and Aurungabad; 
though in ail likelihood it may have been observed over a much more exten- 
sive area than this, from which as yet no observations have reached us. From 
the explosions heard at Aurungabad, it is possible that in this neighbourhood 
it burst. 

" Another meteor, of lesser size, though still of considerable brilliancy, M'as 
seen here on the 23 rd." 

" To the Editor of the Bombay Times. 

" Sir, — The meteor alluded to in your last was seen at this place on Mon- 
day, at six P.M., in the E.N.E. quarter, at an altitude of about 30°; descending 
obliquely towards the E., it disappeared behind a building. I had only a 
glimpse of it myself, my back being towards it at first, but the person with 
me described it as being about half the size of the moon, and much brighter. 
It was seen also at Poorundhur. Instead, therefore, of being a few hundred 
yards distant from your Bombay informant, it must have been certainly more 
than 100 miles : how much more we cannot say, not having its exact bearings, 
but probably another fifty at least. Should it have been seen at Seroor or 
Nuggur, something further may b^ known of it, as it must have been pretty 
near those places. If I can collect anything further about it I will let you 
know W. S. J." 

" Poona, 23rd March, 1849." 

" On Monday (19th), about half-past six in the evening, a very remarkable 
and beautiful meteor was observed at this station. Its course was north- 
easterly ; bursting out in the zenith in a most brilliant manner. It appeared 
to me to have two succeeding periods of intense brilliancy, with intermediate 
diminutions of light ones; occurring on its passage behind a fleecy cloud 
near the horizon, it illuminated it like a sheet of summer lightning would, 
the colour then assuming a vivid green hue. I have never seen any so 
beautiful and striking that I remember as this. — Observer." 

" Sholapore, 25th March." 



40 REPORT — 1849. 

" Sir, — One of your correspondents I see has sent you an account of a 
fire-ball which he saw on Monday (19th) evening last at about half-past six 
o'clock. The same meteor was visible here at Surat ; and so much did its 
extreme brilliancy and very rapid motion give the appearance of nearness to 
it, that we thought it must have fallen close to the tow n. Of course to speak 
by the card, we ought to say that at about half-past six we saw a meteor 
which, iS'c. &c., but you will see from what follows, that it is not a very rash 
inference to conclude it to be the same. If you can get from some of your 
friends an estimate of its apparent altitude, and the direction of its motion as 
seen at Bombay, the data sent with this will perhaps help you to a rough 
approximation to its real height, volume, and path. It passed then from 
west to east across our meridian to the south of us ; was about 30° high 
when first seen, and perhaps 10° when it vanished (25° perhaps when on the 
meridian), and must have had an apparent diameter of 4' or 5' (say for the 
sake of comparison with other estimates, about one-eighth of the diameter of 
the moon). It was intensely incandescent, the surface appearing as if liquid 
with heat (having so large a diameter, one seemed to be able to look well 
into the surface); in colour white, with perhaps a slight tinge of green. 
(Query — the optical effect of contrast with an evening sky?) — H." 

" p.S. — A friend accustomed to estimate angular magnitudes, and who saw 
the meteor, confirms the account I here give you, but adds that he 'saw the 
train distinctly visible about ,5° higher than Canopus.' This, from the posi- 
tion of Canopus at the time, would give the meridian altitude about 21° 
instead of 25°." 

" Surat, 24th March." 

" Sir, — A meteor of the same description as the one seen in Bombay on 
the evening of the 19th, was also seen at Jaulna at the same hour. — G. F." 

" Camp, Jaulna, March 24." 

" Sir, — The meteor noticed by your correspondent in your last issue was 
also observed by several persons at this station on the same evening, and 
about the same hour (Monday the 19th, half-past six o'clock). It seemed 
to arise a little to the south of, and above Venus, and to travel in a northerly 
direction ; I should say N.N.W. About a minute and a half after it disap- 
peared, two reports, following each other rapidly, were heard, like the ex- 
plosion of a mine at a considerable distance. — Asterca." 

" Aurungabad, 24th March, 1849." 

I have been also favoured with a sight of a private letter from an astro- 
nomical friend to the Editor of the Bombay Times, of which I am permitted 
to give the following extract : — 

" Poona, 2nd April, 1849. 

" Can you make anything out of the diff"erent reports of the meteor 

of the 19th ult., so as to have even a guess at its whereabouts? I cannot 
by any means torture them into an agreement, and have come to the conclu- 
sion that there must have been two at intervals of perhaps fifteen or twenty 
minutes, and that Ihey have been confounded together; e.g. how could the 
same object have passed the south meridian at Surat, at an altitude of 21° 
from W. to E., and also have burst out in the zenith of Sholapoor and moved 
N.E.? The latter could have been seen only to the east of tlie meridian at 
Surat. Also if the interval between the appearance and report at Aurungabad 
is worth anything, the distance from that place could not have been much 
more than twenty miles, and this does not seem to tally well with either of 
the other two. I had no watch about me to note the exact time here, but it 
was only a few minutes after sunset, certainly not so late as a quarter-past 
six, while at Surat the difference of longitude must have made it a trifle 
earlier : so that the times do not agree very well either." 



A CATALOGUE OP OBSERVATIONS OF LUMINOUS METEORS. 41 

No. 10.— Bombay Bi-monthly Times, April 30, 1849. 

" A correspondent mentions that about half-past six on the evening of the 
26th of March, a meteor of considerable magnitude was seen from Cochin, 
travelling in a north-westerly direction. At first it seemed somewhat larger 
than the planet Venus, as now visible: it consisted of a nucleus of bright 
emerald green, with a long tail of an uniform red colour. It burst into frag- 
ments as it approached the earth. Our informant was not aware of any 
report having been heard accompanying the explosion." 

No. 11.— Bombay Bi-monthly Times, April 30, 1849. 

"The meteor of the 13th April (Friday). — A writer in the 'Poona Chronicle' 
gives us a notice of the meteor seen at Hingolee and Bombay on the 13th April, 
and completes the chain of evidence, establishing the fact that it was the same 
body which was visible at all the three points. None of the observers speak 
of its explosion, so we are left to infer that it continued to travel eastward 
beyond the reach of vision. It seems to have proceeded from west south- 
easterly — the Poona observer having obviously first seen it after it had passed 
him, so as to make it appear in the east : proceeding further easterly, Hingo- 
lee is in lat. 77° E., or nearly — Bombay 72° 49'. At the former place it was 
seen at nine very nearly, at the latter at from twelve to fifteen minutes after 
nine. If it travelled at the rate of thirty miles a second — the supposed 
velocity of the meteor of the 19th of March — it would occupy ten seconds 
from Bombay to Hingolee, assuming the distance to be 300 miles : this is an 
amount of time that need not for the present be taken account of; and it 
may be assumed to have been seen at the two points simultaneously. The 
difference of time due to longitude, taking this at four degrees, would be 
sixteen minutes ; and this corresponds very closely with the observed dif- 
ference. The Poona writer, who says he saw it three minutes before nine, is 
obviously wrong — it must have been twelve or thirteen minutes after, he 
means." 

Ibid. From a correspondent : — 

" Last night as a friend and I were seated in a " Chubooturah," in 

front of my house, enjoying a refreshing zephyr that had just sprung up 
after a day of intense heat, and as I was contemplating the blue and spangled 
vault over our heads, my attention was attracted to a beautiful meteor, to 
which I immediately drew my friend's attention. The time, just as the even- 
ing gun had sullenly boomed at nine p.m., and its echo had scarce finished 
reverberating among the adjacent hills, when this body burst into view a little 
to the west and south, just as if the concussion had broken a portion from 
off one of the spheres above, and what we saw was the falling debris. From 
where we were seated, the apparent nucleus, whence it started, seemed not to 
be more than twenty-eight or thirty degrees in height from the to us then 
visible horizon. It left behind it a train of most beautiful light, and which 
appeared to us by no means inconsiderable in breadth — colour tliat of a most 
beautiful 'blue light.' The coruscation lasted for several seconds, when I 
lost sight of it behind my office bungalow. — J. J. H." 

" Hingolee, April 14th, 1849." 

" *** An account of a meteor of the same description exactly, seen at 
Bombay at the same hour of the same evening, appeared in our last. If it 
was the same it has travelled over nearly 300 miles of country from E. to W. 
— Editor." 

No. 12.— Bombay Bi-monthly Times, May 11, 1849. 

" Poona, 2nd May, 1849. 
" On Monday, 30th April, at 7'7, a meteor was seen just under ^ Ursae 



42 REPORT — 1849. 

Minoris, descending obliquely to the left at an angle of about 55°. It 
disappeared at an altitude of about 6°, at which time its azimuth must have 
been N. 10° or 11° E. Its whole visible tract did not exceed 7° or 8°, and 
it was brightest just before disappearing, but did not then exceed a star of 
2nd magnitude. Its colour was dusky red; duration perhaps I5 second. — 
W. S. J." 

Ibid. " Subjoined is an interesting notice of the meteor mentioned in our 
last. May not the circumstance alluded to by our correspondent account 
for the showers of dust and ashes occasionally observed at such vast distances 
from volcanos as to have proved subjects of much perplexity to those trying 
to explain them on the assumption of this being due to eruptions? The 
appearance of red snow, showers of blood, and the like, would be at once 
produced were iron reduced to peroxide by combustion to commingle with 
snow or rain during their fall. 

"'On Thursday* evening, at Malabar Point, half an hour after sunset, I 
observed a splendid meteor about S.S.W., falling slowly on a plane inclined 
at an angle of 80° to the horizon (the acute angle being to the right). Its 
angular velocity about 2° per second. Mean time of obs^ervation 6'52\ p.m. 
It passed about 2° to the left of a star of the first magnitude (viz. Canopus, 
its true altitude being 6° 53', and true bearing S. 27° 28' W.). When first 
noticed it was a few degrees above the star, shining with a steady planetary 
light like Jupiter. When it had fallen to about the same altitude as the star, 
it blazed out with an intensely dazzling white light, brighter than Venus ; 
then quickly fided into a shower of what appeared dull reddish yellow sparks, 
and ended its course in a vertical direction, disappearing when about 2° 
above the horizon. If this was an extra-terrestrial body, the direction of its 
motion in space showed as if it had overtaken the earth or its orbit. If the 
blazing out occurred when entering the atmosphere, its distance from Bombay 
must have been considerable (probably 150 miles), and its size corresponding 
(perhaps thirty yards in diameter). It would be interesting if simultaneous 
observations could determine the height of this blazing appearance that 
almost all meteors have at some part of their course. I forget if Humboldt 
has anything conclusive on the subject. One remark, not to be found in the 
• Cosmos' but nevertheless true, is, that if a 32 lb. iron shot played the part 
of an aerolite and entered the atmosphere with the velocity of ten miles per 
second (a moderate velocity for such bodies), the heat generated by the 
resistance of the atmosphere would be suflScient to raise the temperature of 
the shot one million of degrees. Such an immense and sudden evolution of 
heat would probably not only melt the iron, but oxidize it with an exhibition 
of intense combustion, and the splendid meteor would finish its course by 
gently descending to the ground in the shape of an insignificant red powder. 
Has this been the fate of the young planet of the 19th March?' 

" The meteor was seen at Khandalla a few minutes before seven o'clock, 
travelling from N.W. to S.E., and is described as having been of exceeding 
brilliancv. 

" The* following extract is from a letter received a month since from 
Hoshungabad, dated 6th April : can it be that the thick dust which filled the 
air betwixt the 28th March and 2nd April, was the debris of the meteor of 
the mth (March)? 

" ' From the 28th of March to the 2nd of this month, a haze, occasionally 
very dense, has covered the station. The opposite hills were sometimes invisi- 
ble, and the sun could be viewed with the unprotected eye until he attained an 

* The dav of the month does not appear, it was probably after the meteor of Friday 13th, 
and before the 30th : either 19th or 26th April. 



A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 43 

altitude of 30° or 35°, having all the appearance of a disc of silver, and the 
sanae transpired (?) when about an equal number of degrees above the western 
horizon. On these days an impalpable dust fell and covered all things. Not 
a cloud was to be seen, but this uniform and general haze mantled everything 
day and night, — the moon and some stars of the first magnitude only being 
visible at night. Barometer slightly lower, dew-point steady, electricity 
abundant, and a gentle breeze chiefly from the west. The days felt oppressive, 
and notwithstanding that the haze intercepted the full play of the solar rays, 
the black bulb thermometer reached 120° on the 30tb."' 

No. 13. — Extract from a note to Prof. Powell froto the Rev. J. Slatter, dated 
Rose-hill, August 7, 1849. 

" The observation would seem to favour Sir J. Lubbock's theory of meteors 
shining by reflexion, but for a concomitant circumstance ; just before it ex- 
pired it threw off as it were some bright particles like the snuff of a candle, 
which fell slowly downwards beside it, and were not extinguished till they had 
fallen below the point at which the meteor ceased y^ * A 

to be visible : thus, a ceased at line 1, J 3t line 2. '^ "^ * 

No other impression I think could be left on any ^ ~ 

observer's mind, but that it was matter in a high 2 

state of incandescence. 

"It was to appearance five or six times the size of Vega, and intensely bright. 
I should think from the hour and the fineness of the evening, it will have 
been seen by other observers. It had much the appearance of a fine ball 
from a Roman candle." 

No. 14. — Extract from Mr. Lowe's communication to Prof. Powell. 

" Aug. 8, 1849, lO'' 16". A splendid me- 
teor, more than twice the size of a first mag-- .^-«— ,::-==-r-=-^:r:-*« — ^-r^---'^"'^ 
nitude star, of a conical shape, moved very "^""^ "r J%s~;^ •■'^i^?~-~....,^ 
slowly horizontally from ^ Bootis, passing 

1° below Arcturus with numerous stars left behind ; here it vanished, but in 
about P"- reappeared about 1|° farther on, it having moved onwards in the 
same tract, but invisible until it had gone over 1^° in space; it remained 
visible about S''"- altogether independent of the second of time it was invisible. 
After its second reappearance it was not so brilliant as when first noticed ; 
indeed it had the appearance of moving rapidly from us ; and if we suppose 
it was moving nearly directly away from us, it would have the appearance of 
gliding slowly amongst the stars. At the second apparition it made a con- 
tinuation of its former track 3° in length ; its colour was orange-red. — E. J. L." 

No. 15. — Note from Dr. Hopkins of Birmingham : — 

"On Monday, Feb. 15, 1830, walking from Edgbaston to Birmingham, I 
was startled by the appearance of a brilliant light in the sky, and looking up, 
for my eyes had been turned to the ground, I perceived a bright mass moving 
in a direction from N.E. to S.W. The size of the body appeared nearly that 
of the full moon. It remained visible about two seconds, moving very rapidly, 
then nearly disappeared for a moment, and after being visible about two 
seconds more, suddenly vanished. It left behind it a marked trail of light, 
which was very distinctly visible for a short time after the disappearance of 
the mass. It seemed to have rather a waving motion, but this appearance 
was probably owing to the thickness of the fog, which rendered the light 
much less brilliant than it would otherwise have been ; as it was, the houses 
and other objects were rendered much more distinctly visible than they 



44 REPORT — 1849. 

would have been by the light of the full moon. The exact situation from 
which I had a view of this interesting object was about twenty yards farther 
from Birmingham than the Plough and Harrow public house at Edgbaston ; 
and the time was, as nearly as I can tell, about ten minutes past seven." 

No. 16. — From a letter to the Rev. Prof. Powell : — 

" Birmingham, Sept. 13, 1849. 

" Rev. Sir, — I furnish you with a written account of what I suppose to 
be a meteoric appearance, which I saw some years ago at Palamcottah, in 
South India. I am unable to lay my hand at present upon a brief memo- 
randum which I believe I made at the time, and therefore cannot furnish the 
date more accurately than to say it was in the year 1838. 

" At about half-past seven o'clocii in the evening, two young men living in a 
house thirty or forty yards from mine, were taking their tea together, with 
their doors and windows all open, as is usual in India, when their attention was 
suddenly attracted to a bright light shining outside, which at first they took 
to be moonlight; but remembering that there was no moon at that time, 
they went outside to see what it could be. They beheld on looking up a 
brilliant object in the heavens, shining more brightly than the moon, and 
instantly came and called me to see it. By the time I had reached the out- 
side of my house, its brilliance had considerably faded, but even then it was 
a glorious object. Its position was directly north, its elevation about forty- 
five degrees, perhaps a little higher ; its form I well remember, because of its 
resemblance to a letter in the Tamul alphabet, and its whole surface, though 
different in shape, little less than that of the moon. Its shape and relative 

size to the moon may be represented thus. Whatap- 

pear to me to be its great peculiarities were these : / -_ H 
it was perfectly stationary, never moving for a mo- ( ) || 
ment from the place where it was first seen : and it ^^ 
remained visible twenty minutes from the time I first saw it, becoming more 
and more dull and indistinct, till it melted away and was seen no more. I 
should add that it was a starlight night, without a single cloud. 
" I have the honour to be. Sir, 

" Your obedient Servant, 

" G. Pettitt." 

No. 17. — General Results of Observations on Meteors. By Edward 
Joseph Lowe, Esq., F.R.A.S. 

(1.) Periodicity of meteors. 

The following epochs are known as periods when falling stars are abun- 
dant. 

April 22-25, .July 17-26, August 9-11, November 12-14, November 27- 
29, December 6-12. To this number I add October 16-18. 

I have found the month of January frequently to have a brilliant display 
of meteors, but the day is not stationary. In 1844 they were abundant on 
the 26th; 1843, on the 31st ; 1847, on the 11th and 13th; and 1848, on the 
4th. 

The annexed shows when falling stars have been numerous in the various 
epochs since 1841, and when and by whom observed, 
a April epoch 22,-25. 

1848 23 .... on the Clyde by Mr. Symonds. 

Highfield House. . the Author. 

1849 20 id id. 

26 id. .... id. 




A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS, 45 

The greater number this year occurred on the 20th ; the April period has 
become rich in its display of meteors in the last two years. 
i July epoch, 17-26. 

1846 25 .... Highfield House. . the Author. 

30 id. id. 

1849 20 id. id. 

21 id. id. 

23 id. id. 

24- id. id. 

26 id. id. 

27 id. id. 
This epoch was very meagre until the present year. 

a August epoch, 9-11. 
1841 .... 10 .... Plymouth Prof. Phillips. 

9 . . . . Greenwich Mr. Hind. 

1842 9 Gosport Mr. Maverly. 

9 . . . . Greenwich Mr. Hind. 

1843 .... 9-13. . Cork Prof. Phillips. 

10 .... Highfield House. . the Author. 
1S44 10 Durham Mr. Wharton. 

10 Greenwich Mr. Breen, jun. 

1845 10 Paris M. Gravier. 

11 .... Greenwich Mr. Breen, jun. 

10 .... Oxford Prof. Powell. 

1846 10 Dijon M. Perrey. 

12 .... Greenwich Mr. Breen, jun. 

1847 .... 10 Durham Mr. Wharton. 

10 .... Oxford Prof. Powell. 

1848 .... 10 Highfield House. . the Author. 

1849 10 .... id. id. 

10 London Mr. Birt. 

10 .... Gosport Mr. Burney. 

The August epoch rarely ever fails to bring a very abundant display of 
meteors. In 1841 Mr. Hind counted at Greenwich seventy -two meteors, be- 
tween lO** and IS*'; the greatest number in one hour was from 12'' to 13'', 
viz. 24. In 1842, Mr. Hind saw 100 between the ll'' and IS''. The greatest 
number in one hour, from IS"* to 14^ viz. 20. This year (1849), about 
eighty were counted here in an hour, from 10'' to 11''. The meteors for a few 
evenings previous to the 10th, when the sky was in a condition for falling stars 
to be seen, gave an increase in number each evening. The 10th was only 
clear for an hour, viz. from 10'' to II''. 

a October epoch, 16-18. 

184.3 16 Highfield House. . the Author. 

1844 18 id. id. 

1846 .... 16 id. id. 

17 .... Dijon M. Perrey. 

1 847 18 Paris M. Laisne. 

1848 18 Highfield House. . the Author. 

This epoch, which has returned so regularly from 1843, I have not seen 
entered as a period for falling stars. 

d 1st November epoch, 12-14. 

1841 .... 12 , . . . Greenwich Mr.Glaisherand Mr.Dunkiu. 

1843 .... 11 id. .... Mr. Hind and Mr. Paul. 



4G REPORT — 1849. 

d 

1844 12,13.. Birmingham Mr. Onion, 

12, 13. . Higlifield House. . the Author. 

1845 .... 10 .... Greenwich Mr. Lovelace and Mr. Breen, 

jun. 
14 .... Bombaj' Prof. Orlebar. 

1846 .... 11 .... Greenwich Mr. Humphreys, Mr Love- 

lace, and Mr. Breen, jun. 

1847 .... 12, 13. . Dryburn Mr. Wharton. 

12,13.. Highfield House., the Author. 

12, 13. . Benares Correspondent to M. Arago. 

Although this period in former years exceeded all others, still within the 
last few years the August epoch has been more brilliant. 
2nd November epoch, 27-29. 

As yet I have never been fortunate enough to see a meteor on these nights. 
d December epoch, 6—12. 

1845 12 ... . Bombay Prof. Orlebar. 

1847 12 Highfield House. . the Author. 

(2.) Meteors crossing the sun as dark spots. 

In 1839, m Astronomische Nachrichten, No. 385, Prof. Erman stated that the 
cold days of the 1 1th to the 13th of May and the 5th to the 7th of February, 
were owing to the passage of falling stars between us and the sun. 

In 1845, the German astronomer Peters had taken observations on solar 
spots, which he requested the Astronomer Royal Capocci to have continued. 
One of the assistants (M, de Gasparis) being thus occupied on the 11th of 
May 1845, observed a black body cross the sun ; he called Capocci's attention 
to the fact, and he, together with Dr, Ddtoartini and an assistant astronomer 
(Del Re), witnessed great numbers cross his disc. Being on a visit with my 
worthy friend Mr. Lawson at Bath (this year), we determined to watch 
carefully for these black globules, and accordingly set the 11-foot equatoreal 
to the focus of the sun ; a 5-foot to that of Venus; a 3-foot to that of the 
moon; and a beautiful defining glass of thirty inches, to 400 miles, thinking 
by this arrangement to be enabled to detect these bodies, whatever distance 
they might be from us ; unfortunately, from February 5th to 7th, the sun 
never shone at Bath ; however, we received a communication from Mr. 
Weeks of Sandwich, saying his friend the Rev. Mr. Brown of Deal had seen 
two deliberately cross the sun's disc .in a descending arc. We looked out 
again on the 11th, 12th and 13th of May, but without success. Conversing 
with my friend Mr. Hind, he informed me that Messier* remarked, that in 
1777 one day he had seen 200 small dark bodies cross the solar disc; to say 
the least of the phaenomenon, it is worthy of a few years' attention before we 
decide this interesting point, especially as the November meteors frequently 
fail to give us a rich display. 

(3.) On a point of divergence of meteors. 

The meteors seen in 1839 diverged from a point situated between Taurus 
and Pegasus ; since then the point is stated to be near /3 Camelopardalis. 
Both last year (1848) and this (1849), from a great number of observations, 
the point of divergence was in or slightly above Cassiopeia on the 9th to the 
18th of August, yet, strange to say, until then this point was not observed: 
there was another situated in Cygnus, which had been plainly discernible since 
the middle of July. From that time until the 9th of August, if the paths of 

* Messier gave a memoir on the subject, entitled, " Observation singulier d'une prodigieuse 
quantite de petites globules qui ont passe au devant du disque du soleil." [Mem. Acad. Paris, 
1777, p. 464.] 



A CATALOGUE OP OBSERVATIONS OP LUMINOUS METEORS. 47 

the meteors were produced backwards they would nearly all meet at a point 
situated to the east oi Alpha Cygni, and on the 10th were near the star Alpha. 
The number of stars seen this year on August 10th was about eighty, the 
sky being clear for an hour, from shortly before 10 o'clock to near 11 o'clock. 
Fifty-five of these had their paths and other features recorded here ; out of 
this number the following are those noticed proceeding from the direction of 
these two points of divergence : — 

From Cygnus 23 

From Cassiopeia .... 26 

Discordant 6 

55 
In 1848. 

From Cygnus 5 

From Cassiopeia .... 8 

13 

The two following letters to Prof. Powell will further illustrate this point. 

" My dear Sir, — The opinion that falling stars diverge from a given point 
at two periods of the year, viz. August the 10th and November the 11th, is 
generally believed, but I have seen no hint that they do so at other times ; 
that they nearly all do I feel perfectly persuaded. From numerous observa- 
tions on the 20th and 21st of this month, I find they diverge from about the 
centre of the constellation Cygnus ; last night (July 23rd), which was particu- 
larly rich in falling stars, gave a position slightly different, viz. l, Cygni for 
the mean point from which thej'' diverged ; if this point was more attended to, 
in all probability we should soon have sufficient data to enable us to give at 
all events a rough element. From a few observations during June, this point 
would seem to be in Draco, in beginning of May in Bootis, and in April in 
Canes Venatici. The meteors were few in number in April, May and June, 
but are now each night becoming much more numerous. 

" The tail, as it is called, of meteors is apparently of two kinds, the one a 
continuous streak of light, and the other individual sparks ; this does not 
seem to be owing to the speed with which they move, tor I have frequently 
seen each appearance, whether the meteor was moving rapidly or slowly. 

" Believe me yours very truly, 
" Highfield House Observatory, near Nottingham, " Edward Joseph Lowe." 

July 24, 1849." 

"July 28, 1849. 

" My dear Sir,— Out of the nine observations on the 26th of July, six gave 
a point of divergence slightly below p Cygni. Some of the observations last 
night gave a position rather lower in the Swan. It is pretty evident there is 
a point of divergence, and that this point is now situated in the Swan, for 
each night produces more examples of meteors coming from that direction. 

" Believe me yours very truly, 

" Edward Joseph Lowe." 

In 184'2, Prof. Phillips noticed many meteors came from the direction of 
Cassiopeia, and in ISiS the Rev. C. Marriott at Bradfield again noticed this 
feature in one instance. 

It seems quite evident that the greater portion of these bodies move in 
lines parallel to each other; for as proof that the point of divergence is merely 
owing to perspective, the greater number of stars to the S. and S.E. of us 
move towards S. and SS.W-i whilst those to W. and N.W. move towards W. 
and W.S.W. This was very evident on the lOtli of August this year, for a 
great number which occurred in Pegasus all moved to S. and SS.W., whereas 



48 REPORT— 1849. 

those in Ursa Major, Ursa Minor and Draco descended towards W. and 

W.S.W. 

(4.) Interesting features in Meteors of August lOtli, ISiS. ^ 

In fifty-live meteors recorded on this nigiit, in eleven cases a second falling 

star moved almost immediately afterwards in the same or nearly similar track 

to that which had just gone before ; these occurred at 

h m „ / // 

9 56 followed by another in same track in 2 

9 59 „ „ „ 1 

10 3 „ „ „ 1 

10 5 30 „ „ „ 30 

10 7 „ „ „ 30 

10 8 „ „ „ 30 

10 11 „ „ „ 15 

10 13 „ „ „ 1 

10 17 „ two others „ |^ g^* 

10 30 „ another „ 3 

10 38 „ „ „ 30 

The meteors on the 10th mostly moved exceedingly rapid ; 48 are entered 
as moving quickly and only 6 as slow. They were generally accompanied 
by continuous streaks of light, which they left behind them for one or more 
seconds; that which occurred at lO** 5™ 30" left a ray of light visible for 31" 
after the head of the meteor had vanished, which was 7° in length. 24- are 
entered as having tails, and 4 without tails. 

The number seen each five minutes during the hour they were visible, was 

h m b m Falling stars. 

from 9 56 to 10 4 

10 5 3 

5 10 9 

10 15 4 

15 20 6 

20 25 6 

25 30 4 

30 35 4 

35 40 6 

40 45 3 

45 50 4 

50 52 2 

» The distribution of colours amongst the meteors, was — 

Colour. No. of Meteors. 

Yellow 14 

Red 7 

Blue 5 

Colourless 2 

The apparent size, as compared with other objects, was as follows : — 

No. of Meteors. 
Rather larger than Venus when nearest 0. . . . 1 

Size of Venus , 5 

„ Jupiter 6 

„ 1st mag. star 8 

„ 2nd mag. star 3 

,> 3rd mag. star and smaller 32 

* i\t this time three moved in the same track. 



A CATALOGUE OF OBSERVATIONS OP LUMINOUS METEORS. 49 

In the 55 falling stars 8 became first visible in Pegasus, 8 in Cygnus, 6 in 
Andromeda, 5 in Ursa Minor, 4 in Delphinus, 4 in Cassiopeia, 3 in Antinoua 
and Ursa Major, 2 in Aquila, Aquarius, Lyra, Corona Borealis and Cepheus, 
and 1 in Pisces, Bootes, Perseus and Camelopardalis. Of these 8 became 
extinguished in Draco and 8 in Pegasus, 6 in Antinous, 4 in Pisces, 3 in 
Cygnus, Aquarius, Lyra and Bootes, 2 in Sagitta, Cassiopeia, Ursa Major 
and Perseus, and 1 in Andromeda, Delphinus, Ursa Minor, Coma, Berenices, 
Serpens, Capricornus, Hercules, Camelopardalis and Triangulum. 

It is pretty evident that the meteors were nearer us on the 10th of August 
very considerably than on the 16th, as on the latter day, although a few tole- 
rably sized ones were seen, yet the great majority were meteors very brilliant 
for their size, which was smaller than the smallest stars that could be discerned 
by the unassisted eye. 

(5.) It is a curious fact, that when a falling star is seen to follow another in 
the same track, it invariably moves at an equal speed with the one which had 
gone before, i. e. if the first moved rapidly the second would do so also, and if 
slowly the second would move slowly. The second star I have never as yet 
seen larger than the first ; and generally there has been a considerable differ- 
ence in apparent size, from the circumstance of the follower of a falling star 
in the same track partaking of the speed of that which has gone before, and 
that generally the respective bulks are very different; it might be supposed 
that the smaller one was an attendant or satellite of the larger one ; if this be 
the case, the meteor that fell at 10^ 17"* was accompanied by two satellites; 
this strengthens the opinion very much of their being material bodies. 

On the other hand, if we consider them as shining by reflected light, it is 
difficult to account for the luminous streak which is often left in the sky- 
after the head of a meteor has itself vanished, and also why a meteor having 
a continuous ray of light, if it cross an auroral arch or beam, instantly 
brightens, a circumstance exceedingly curious and at the same time very 
apparent : the phaenomenon has been noticed here four times, viz. December 
3, 1845, September 10, 1846, June 21, 1847, February 20, 1818. 

As there are several difficulties attending this phaenomenon if we account 
for them all with one theory or consider them all to be similar in formation, 
I have ventured to suggest three classes : — 

1st. Those with luminous streaks. 

2nd. Those with separate stars, and those without any appendage. 

3rd. Those large bodies with well-defined discs. 

The 1st class may shine by inherent light or be surrounded by a luminous 
atmosphei'e ; the 2nd class by reflected light, as described by Sir John 
Lubbock ; and the 3rd class may be purely atmospherical; as this kind nearly 
always move in paths discordant to the direction of the other meteors, they 
are not always spherical, and sometimes change their form : I have seen them 
alter their colour from blue to red, and in one instance saw a meteor of a blue 
colour give out orange-red sparks. Mr. Hind tells me he saw a green meteor 
turn to a crimson colour. 

I have made numerous inquiries, but could never find any one, excepting 
Mr. Hind, who had seen meteors move slowly across the field of a large tele- 
scope ; he describes them as appearing better defined than stars, which they 
resemble, but the time of visibility was too short to allow of a planetary disc 
to be discovered ; the fragments or streamers appeared like phosphoric 
lights. 

1849. E 



50 



REPORT— 1849. 



No. 18. — Details of Observations of Meteors. By W. R. Birt. 

Projection in the plane of the horizon of fourteen shooting stars, observed 
at Highfield House, near Nottingham, by E. J. Lowe, Esq., on the evening 
of the 10th of August 1849, between 9*^ 56™ p.m. and 10'' 16" p.m. 

The circle bounding the projection represents the horizon, and its centre 
the zenith. 

The line N — S the meridian arc. 

The lineW — E the prime vertical. 

The arrow-head indicates the direction of the earth's orbitual motion at 
the time of observation, the portion of the horizon N, W being directed 
towards the sun. 

The shooting stars marked a and b are considered to be identical with two 
observed at London. 

(1.) N 









•••-... 




/ 
; 


K^ 






''•■^ 


\ 

A, 


■* — 


1 ^"■* 

is 
/I / 


\ 


1 t 




-. I 


i ; 







Projection in the plane of the horizon of two shooting stars observed at 
London by W. R. Birt, near 10 p.m. of the evening of the 10th of August 
1849. 

The letters a and b refer to those shooting stai's observed at Nottingham, 
which are considered to be identical with them. 

(2.) T. 



/ Ih 



\ >(f 



A CATALOGUE OP OBSERVATIONS OP LUMINOUS METEORS. 51 

(3.) Observations on luminous meteors, August 10, 1849. 

a No. 1. Between 9^ 30"^ p.m. and 9'' 33™ p.m., a rather large luminous 
meteor shot from the Via Lactea, nearly midway between Cygnus and Cas- 
siopeia; it was nearer Cassiopeia than Cygnus; its path was apparently 
straight, across Lacerta, and the point of disappearance between Cygnus and 
Pegasus considerably below the former and much nearer the latter. It 
scarcely passed, if at all, the line joining a Cygni and /3 Pegasi. It left a 
train of reddish scintillations, which were more conspicuous about the middle 
of its course, dying away at each extremity. 

a No. 2. A small meteor, between one and two degrees cast of Polaris, 
passing downwards. 

a No. 3. A luminous meteor passing between a and j8 Pegasi, and cutting 
the line joining them very obliquely; its direction appeared to be parallel to 
the meridian towards the south ; it was small and of short duration, but rather 
larger than No. 2. 

a No. 4. A small luminous meteor, near the head of Capricornus, passing 
south and west. 

a No. 5. 

a No. 6. At about a minute or two before 10'' p.m., a rather large lumi- 
nous meteor shot from above and to the north of Cassiopeia and disappeared 
just to the north of Cygnus, the points of appearance and disappearance 
being within the boundaries of each constellation; its apparent path, which 
was straight, appears to have crossed the head of Cepheus. It was attended 
by a train of reddish scintillations, more conspicuous in the middle, and 
dying away at each extremity. This meteor was extremely similar to a No. 1 
in every respect, save one, viz. direction. The directions of these meteors 
did not appear to be parallel, but such as to give the idea of divergence ; the 
line of direction of a No. 1 produced backwards, intersecting that of a No. 6 
about the point of its commencement. 

The above meteors were the only ones seen between 9^* 30™ p.m. and lO**. 
They were all of a blue colour. 

b No. 1 (?). At a very few minutes after lO'' p.m., a very large and bright 
meteor shot from beneath the tail of Ursa Major (the constellation at the 
time being covered with a cloud), most probably in the neighbourhood of 
Cor. Caroli ; it crossed about the middle of Bootes, s Bootes (?), and vanished 
to the south of Corona Borealis. I much regret I did not obtain a full view 
of this fine meteor, which was by far the largest hitherto seen, and I should 
conceive exhibited the longest path, being engaged at the moment in con- 
templating Cassiopeia. The light attracted my attention, and on turning I 
just caught a sufficient glimpse of the meteor to assure me of its magnitude 
and direction. I had a full view of the train of reddish scintillations which 
it left behind ; this train perfectly agreed with the two I had previously 
witnessed ; its direction appeared to be very nearly if not quite parallel to the 
horizon ; it indicated that the path of the meteor was straight. 

b No. 2 (?). A small but bright meteor passed directly over Polaris, bisect- 
ing the star; its course appeared to be in the meridian towards the horizon. 

N.B. I am not quite certain which of these meteors occurred earliest, but 
I strongly suspect that b No. 1 was first. 

b No. 3. 

b No. 4. A very splendid globular meteor, abo\it the size of Jupiter at 
opposition, of a whitish colour, very slightly tinged with red, passed with a 
comparatively slow motion immediately over y Pegasi (the star was bisected). 
Its path, which was slightly curved, was nearly parallel to the horizon, and 
the meteor increased in brilliancy as it proceeded until its disappearance, 

e2 



52 REPORT — 1849. 

the point of which could not have been far removed from the line joining a 
and /3 Pegasi, and produced : y Pegasi was about midway of its apparent 
path. The path suggested the idea of that of a projectile, the meteor sensi- 
bly bending to the earth just before the disappearance : there was no train, and 
the meteor was exceedingly unlike any of the preceding. 

h No. 5. Within a very short interval, I should say less than a minute, 
another meteor, of precisely the same size and exhibiting precisely the same 
characters in every respect, not one excepted, appeared just beyond the point 
of disappearance of b No. 4. Its path appeared to be a prolongation of that 
of b No. 4, and it disappeared in exactly the same manner, slightly bending 
to the earth, or rather horizon, not far from /3 Aquarii. 

Assuming for the moment, which is not altogether improbable, that the 
two were only one meteor, which by some means had been extinguished for 
a short time during its progress, its visible path in the heavens at London 
would at least be from 15° north Dec. 0° Rt. Asc. to 6° south Dec. 320° Rt. 
Asc. retrograde, and it crossed the equinoctial about 332° Rt. Asc. 

b Nos. 1 to 5 occurred by estimation between lO*" p.m. and lO** 15™ p.m., 
certainly not later than 10*^ 20" p.m. The appearance of b Nos. 4 and 5 
most probably occurred at 10*^ 15"' p.m. 

Remarhs on the above Meteors. 

Of the above meteors five claim particular attention, viz. a Nos. 1 and 6 
and b Nos. 1 (?), 4 and 5, a Nos. 1 and 6 occurring previous to lO*" p.m., 
and b Nos. 1 (?), 4 and 5 after 10'' p.m. Each of these meteors are very 
readily identifiable. After a No. 1 had appeared, a considerable time elapsed 
before a No. 2 was seen in the neighbourhood of Polaris, and the directions 
of these meteors were very different and nearly opposite. Nearly half an 
hour elapsed before a No. 6 became visible, its direction and that of a No. 1, 
as before remarked, indicating a point of divergence just north of Cassiopeia. 
With the exception of the meteors in the neighbourhood of Polaris and that 
between a and /3 Pegasi, those seen in the eastern hemisphere, viz. a Nos. 1, 
4 and 6, and b Nos. 4 and 5, were directed more or less towards the meridian, 
b No. 1 (?) was the only meteor seen westward of the meridian ; and it is 
worthy of remark, that while the direction of its motion was towards the 
meiidian, it was in the opposite direction to those in the eastern hemisphere, 
and this appears to indicate a point of convergence in the south, as well as a 
point of divergence in the north. These phaenomena may greatly assist in 
determining the position in space of these bodies. It is clear that at the 
time of observation, the earth was moving towards a given point in the 
heavens. The general direction of the meteors in the eastern hemisphere 
was retrograde, while that in Bootes was direct. Assuming for a moment 
that between 9^ SO"" and lO** 30"" the earth passed very near a small cluster 
of meteoric bodies, which was moving in a contrary direction, the majority 
being south of the earth's path, and one only north, the phaenomena would 
be just as witnessed. All the southern meteors would have a retrograde 
motion, while that of the northern would still coincide in the general direc- 
tion of motion ; but instead of its being retrograde it would be direct, just as 
a traveller on a railway sees the objects apparently rushing past him on each 
side, their apparent motions being identically the same ; yet when these 
jnotions are referred to the circle of which he is the centre, it is evident those 
on his left-hand must have an opposite expression to those on his right. 

Upon a comparison of the paths of a Nos. 1 and 6 and b No. 1, which 
appear, with the exception probably of the globular meteors b Nos. 4 and 5, 
to have been nearest the earth, wc may be better able to judge of their 



NEBULA LATELY OBSERVED IN THE SIX-FEET REFLECTOU. 53 

relative positions, especiallj' with respect to the earth. Taking Lacerta as 
the middle point of the path of a No. 1, the head of Cepheus as that of 
a No. 6 and a Bootes as that of b No. 1, it is very evident that the earth, or at 
least its centre, must liave passed considerably to the south of the plane 
passing through the centres of « No. 6 and b No. 1, and as b No. 1 appeared 
but a few minutes after a No. 6, the distance between them would be con- 
siderably less than that between a No. 1 and either of the others. If, as has 
been suggested, the direction of the earth's motion was such as to leave the 
meteor b No. 1 on the north and a No. 6 on the south, both would be suf- 
ficiently identifiable at any part of the earth's surface from which they might 
be visible : — 1st, from the priority of the southern meteor ; and 2nd, from the 
apparent opposition of their motions ; and should observations have been 
made from which the altitudes of each above the earth's surface may be 
deduced, it would not be very difficult to determine approximately and 
within certain limits their distance from each other, due allowance being 
made for the earth's motion between the instants of apparition. In connexion 
with the view here taken of the relative positions of these three bodies, the 
StraightTiess of their paths strongly indicates the passage of the earth past 
them. Upon M. Quetelet's determination of the mean altitude of these 
bodies being sixteen or twenty leagues, it would appear that when the nearest 
point of the earth's surface approaches a meteoric body at or witiiin this 
distance, the phaenomena witnessed would be produced : the body would 
pass through a segment of the earth's atmosphere, the path most probably 
differing but little from a straight line ; upon entering the earth's atmosphere 
combustion may take place, as suggested by Prof. Powell, and this may give 
rise^ to the reddish scintillations so apparent in the three bodies observed ; 
these scintillations presented phaenomena perfectly in accordance with this 
notion, being most intense in the middle or deepest part of the earth's atmo- 
sphere, and gradually dying off at each extremity. 

The meteors b Nos. 4- and 5 appeared to be essentially different from the 
three we have just noticed; the well-defined globular appearance they 
presented, the comparative slowness of their motion, the slight curvature of 
their paths, and their decided increase of brilliancy just previous to their 
extinction, place them altogether in a different category, and would lead one 
to expect that at more southern stations they appeared both larger and more 
brilliant. It would be interesting to obtain observations of these meteors 
(which certainly were unmistakeable in their character) from places at which 
they were vertical. At present however we must be content with knowing 
that of the group of meteors observed they were probably the most southern, 
the plane of their motion being less inclined to the ecliptic than to the 
equinoctial. 



Notice of Nebula lately observed in the Six-feet Reflector. By the 
Earl of Rosse, Pres. R.S. Communicated by the Rev. Dr. 
Robinson, Pres. B.A., and ordered to be printed entire among the 
Reports. 

At the Meeting of the British Association at York in 1844, it was an- 
nounced that a reflecting telescope of six-feet aperture, which had been 
about two years in progress, was nearly completed, and some slight account 
was at the same time given of the means which had been taken to render the 
wstrument convenient and effective. A short notice of the principal results 



54 REPORT — 1849. 

which have since been obtained may perhaps not be uninteresting to the pre- 
sent meeting. 

About the beginning of February 1S4'5, the instrument was so far finished as 
to be usable ; and in the first instance it was directed to some of the brighter 
nebulae in Herschel's Catalogue. Many of them were immediately resolved, 
and very frequently the aspect and form of well-known nebulae were com- 
pletely changed, fainter details not previously seen being brought out by the 
great light and magnifying power of the telescope. Before the end of April 
the wonderful spiral arrangement in 51 Messier was discovered. The specu- 
lum, though there was a slight defect of figure, was in fine working order, and 
defined with great sharpness when the air was steady. 

At the approach of the short nights, when the season for observing the ne- 
bulae was nearly over, the instrument was dismounted, as it was desirable to 
take the earliest opportunity of completing certain portions of the mechanism 
which had been put together in a temporary way in a rough state, and it was 
not till the close of the year that it was again in working order. 

During the year 1846 the examination of the nebulae in Herschel's Cata- 
logue w-as continued ; many sketches were made, and another spiral nebula 
was discovered, 99 Messier. The moon was observed occasionally, and the 
superiority of the instrument with six-feet aperture over that of three under 
equal magnifying powers, in bringing out minute details, was very remark- 
able ; so great is the effect of light even when we have to deal with an object 
so bright as the moon with an aperture of three feet. 

As yet, however, but little time has been devoted to an examination of the 
moon : the moonlight nights have usually been taken advantage of for expe- 
riments on the polishing and figuring of the mirrors ; and the information 
which has been obtained relates principally to matters of detail, from which 
it would be premature to attempt to deduce general conclusions suitable to 
the present notice. 

In the succeeding year, 184-7, there was but little done; unprovided at 
that time with an assistant capable of making trustworthy use of the pencil 
and micrometer, and being almost wholly occupied with the duties incidental 
to a year of famine, it was impossible to do more than re-examine a few of the 
objects of the previous year. 

From the beginning however of the year 1848 till the present time, the 
instrument has been constantly employed whenever the season and weather 
permitted it, and the following are some of the results : — H. 604 was found 
in some degree to resemble the great spiral nebula 51 Messier, but it is a 
much fainter object, and appears to be made up of elliptic streaks disposed 
rather irregularly with a tendency to spirality, but without that distinct sym- 
metrical spiral arrangement which is so marked a feature of 51 Messier. If 
51 Messier were seen somewhat obliquely, and were considerably fainter, it 
would probably very closely resemble it. 

H. 854, M. 65, has an arrangement of very elliptic annuli, and is apparently 
a system of the same class seen very obliquely. 

M. 97, H. 838, is a very extraordinary object; with a dark hollow centre 
somewhat in the shape of a figure of eight, easily seen, and with a disc irre- 
gularly shaded, but showing in the shading a decided tendency to spirality 
when seen under favourable circumstances : two stars are placed in a re- 
markable manner in the central opening. Wo may conceive it to be a spiral 
system greatly compressed; the edges are filamentous: H 2205 has a faint 
but large spiral appendage, to which the ray as figured by Herschel is in some 
measure a tangent. Several other nebulae are recorded in our note-books as 
belonging to the class of spirals. The well-known planetary nebula in Aqua- 



NEBULJE LATELY OBSERVED IN THE SIX-FEET REFLECTOR. 55 

rius, H. 2098, which in former years had been often examined with a tele- 
scope of three-feet aperture, and with no other result than that it exhibited 
a filamentous edge, when seen with the great instrument was found to have 
two ansae like Saturn. Many have since seen it, and the resemblance to 
Saturn out of focus has usually suggested itself. It is probably a globular 
system surrounded by a ring seen edgeways ; while H. 450, which turns out 
to have a bright centre surrounded by a comparatively dark ring, and that 
again by a bright ring, though a much fainter object, is not improbably a 
system of the same character seen directlj\ 

H. 84 and 86 is a remarkable group of nebulae ; it consists of eight, 
two of them pretty bright. Such groups are not uncommon, but in this 
instance there are I believe more nebulae in a given space than in any other 
group we have noticed ; it was observed by Mr. Stoney. The nebulae were not 
connected by any perceptible nebulosity, but there are cases where a nebulous 
connection was distinctly traced ; several minute nebulge or nebulous knots 
hanging together as it were by a very faint but unmistakeable nebulosity. 
The nebulae of Andromeda and Orion have of course been observed. As to 
Andromeda, there seems to be little doubt that the companion is resolvable, 
and the nucleus of the great nebula has that granular appearance which in- 
dicates resolvability : it has however not been seen as yet under very favour- 
able circumstances, and we have not commenced a sketch of it. The nucleus 
was examined on three occasions, and the abrupt edge of the following streak 
in Mr. Bond's drawing was traced to its visible limits ; but unfortunately we 
did not receive the drawing till the nebula was out of reach, otherwise of 
course more attention would have been directed to it. Subsequent to the re- 
ceipt of the drawing, the nebula was seen by Mr. Stoney in my absence with 
the instrument of three-feet aperture, but at a distance from the meridian : 
the appearance was very much as in Mr. Bond's drawing, except that the con- 
trast between the preceding portion bounded by the edge of the following 
streak, and the following portion of the nebula was much greater. 

The question however of most interest is, what do these streaks indicate ? 
With the great instrument, dark streaks have been observed in many of the 
nebulae, sometimes almost straight, as in Andromeda; for instance, H. 887, 
H. 1909, H. 1041, H. 1149, are cases in point, the streaks being nearly 
straight. H. 1357, to which Mr. Bond refers, is, if possible, a still stronger 
case than it appears to be by Herschel's drawing, as I find a sketch in our 
journal showing that the appendage is part of the nebula, the nebulosity ex- 
tending and encasing both extremities of the opening just as in Andromeda, 
We have also found a variety of examples of curved streaks ; for instance, 
H. 264, H. 491, H. 406, H. 731, H. 854, H. 875, H. 1225, and others. 

Also H. 1486, H. 464, H. 2241, besides the well-known annular nebula, 
and the little annular nebula sketched by Herschel, are some of the examples 
of nebulae with comparatively dark centres ; the darkness being apparently of 
the same quality as the dark streaks, but of a different shape. 

W^ith these facts therefore I think it not improbable that the dark lines 
noticed by Mr. Bond in the nebula of Andromeda, and which with sufficient 
power are perceptible in so many other nebulas, sometimes nearly straight, 
sometimes variously curved, as also the dark spaces, are all indications of 
systematic arrangement. When we see a dark space in the centre of a pla- 
netary nebula, it is impossible to resist the impression that we are looking at 
an annular system bound together by some mysterious dynamical law. If 
we see a bright centre, as in H. 450, surrounded by a dark annulus, and that 
again by a bright annulus, we have a system of another kind ; and in the 
spirals, of which 51 Messier is the most remarkable example we yet have found, 



56 REPORT — 1849. 

we have a regularity of arrangement equally accordant with our preconceived 
notions of the order which should subsist in a regular independent system. 

The very elongated elliptic annular nebulae, where the minor axis is some- 
times almost evanescent, show us pretty clearly the nature of the slight, long, 
dark and nearly straight streak in some cases found parallel to the axis of a 
long ray. A little consideration of the appearances which annular and spiral 
systems must present when viewed in different positions, in some instances 
affords a pretty satisfactory explanation of the confused streakincss we have 
observed in several of the nebulas. 

This, however unsatisfactory it may appear, is the best explanation our 
working journal-books at present afford of the streaks observed by Mr. Bond 
in the nebula of Andromeda. 

Mr. Bond's paper has excited so much interest, and I have been so often 
questioned relative to it, that I have prematurely, in anticipation of more nu- 
merous sketches and measurements, which will probably throw additional 
light on the subject, ventured to lay before the Association the very littlej 
which is at present known to us. 

It was in the spring of ISiS that we first perceived the brighter portions 
of the nebula of Orion in tlie neighbourhood of the trapezium breaking up 
into minute stars. Whenever the sixth star was nicely separated, this appear- 
ance was clearly perceptible. We had repeatedly examined Orion with the 
telescope of three-feet aperture, without a suspicion of its being resolvable ; 
however, its resolvable character once known, we were enabled with it on very 
fine nights to see some of the stars. With the six-feet telescope, the space 
within the trapezium is still dark, just as Herschel describes it, and I feel con- 
vinced there is no optical illusion. 

Last season my attention was directed by Mr. Stoney to i Orionis, which is 
on the edge of a dark spot ; the dark spot includes the nearer companion, 
and is about 12" diameter ; we have not yet had an opportunity of examining 
it with the great instrument. 

A few copies from our collection of sketches accompany this notice : they 
have been made within the last day or two by a drawing-master in the neigh- 
bourhood. He has transposed white for black, and enlarged the scale to 
make them more suitable for exhibition in the Section. 

In sketching, we employ solely the black-lead pencil, black representing 
light, and the eye by habit makes the transposition without effort. 

The copies are not quite accurate, but they are sufficiently exact for the 
purpose. 



On the Influence of Carbonic Acid Gas on the health of Plants, espe- 
cially of those allied to the Fossil Remains found in the Coal For- 
mation. By Professor Charles G. B. Daubeny, M.D., F.R.S. ^c. 
" At the Meeting of the British Association for the Advancement of Science 
held at Oxford in 184'7, it was resolved, that a Committee, consisting of Sir 
H. T. De la Beche, Sir W. J. Hooker, Dr. Daubeny, Dr. J. D. Hooker, 
Mr. A. Henfrey, and Mr. R. Hunt, be requested to investigate the influence 
of carbonic acid on the growth of plants allied to those found in the coal 
formation." 

This investigation was accordingly entered upon by myself in the spring 
of 184^8, by means of an apparatus consisting of two jars of corresponding 
size, each containing about 2800 cubic inches of air, the edges of which 



INFLUENCE OF CARBONIC ACID GAS ON HEALTH OF PLANTS. 57 

rested upon a smooth slate table, having two circular holes perforated in it, 
into each of which a pan or pot containing the plants to be experimented 
upon was inserted. 

By the aid of this apparatus I carried on a series of experiments both on 
flowering plants and on ferns, from which I inferred that the one as well as 
the other would continue for a fortnight at least unaffected by a dose of car- 
bonic acid, bearing a proportion to the whole volume of air equal to from 
5 to 10 per cent., but that 20 per cent, would prove injurious to the one, as 
well as to the other, in the course of two or three days. These results were 
however not offered to the Association at Swansea with any confidence, because 
the apparatus contrived for the purpose of carrying them on turned out to 
be defective, the difficulty of cementing the vessels containing the plants to 
the slate table, so as to render the apparatus impervious to air, being such, 
that a large supply of gas was each day found requisite, in order to keep up 
the percentage to the intended amount. Hence it was probable that during 
a portion of the time the real quantity of carbonic acid in the jar might have 
fallen very short of that with which it was proposed to operate. 

I therefore renewed the experiments in the spring and summer of the pre- 
sent year ISW, in two ways, either of which had been ascertained by previous 
trials to preclude in a great degree the danger of leakage, and thus to render 
the amount of carbonic acid present whilst the experiment was being carried 
on, tolerably constant. 

The first was that of allowing the jars, the edges of which had been well 
ground, to rest upon the surface of a solid and smooth slate table, greased 
along the line of its contact with the glass ; the other to make them dip into 
shallow iron dishes with double rims, containing water to the depth of an inch, 
so that the air of the jar might be cut off from the external atmosphere. In 
neither of these cases was there a sufficient loss of gas to interfere with the 
results ; in the former, the transmission of air between the smooth surfaces 
of the slate table and the jar being inconsiderable, and in the latter, the quan- 
tity of gas carried off by solution in the water being much reduced, when the 
latter was covered with a thin pellicle of oil. Whatever indeed might be the 
loss in either case sustained, I took care to supply it, by introducing the 
requisite quantity once every twenty-four hours into the jars which contained 
the plants. 

I am therefore now able to offer to the Association, with rather greater 
confidence than before, the following results, as confirmatory of those which 
were stated verbally in my Report, but which, for the reasons already assigned, 
were not published in the Transactions of the Association for last year. 

May 14th. — In the first experiment, five healthy ferns, named Nephrodium 
molle, Adiantum cuneatum, Gymnogramma chrysophylla, and two species of 
Pteris, viz. longifolia and serrulata, were introduced into jar 1 standing in 
water, and a quantity of carbonic acid gas was admitted, which equaled 5 
per cent, of the whole amount of air present in the jar. No perceptible change 
occurring, the quantity was increased on the 17th to 10 per cent., and this 
amount was maintained, as nearly as possible to the same point, by occasional 
additions of the gas, till May 27th. 

At the expiration of ten days there was no perceptible difference in the ap- 
pearance of the ferns, either with reference to their preceding condition, or 
by comparison with that of five similar ferns, which had been kept for the 
same time under the corresponding glass, without any admixture of carbonic 
acid gas. The experiment was then continued till June 21st, so that the plants 
were exposed to the influence of carbonic acid gas in all for a period of thirty- 



58 REPORT — 1849. 

three days, besides being subjected for seven days to about 5 per cent, of the 
same. At the end of this time only two of the ferns appeared at all damaged, 
namely Pier is longifolia and Nephrodium molle, the fronds of both which were 
rather discoloured, those of the other three species remaining as before. 

The same description of experiment was made upon a species of Pelargo- 
nium, which after having been during twenty-seven days exposed to the ac- 
tion of 10 per cent, of carbonic acid contained in the air of a large jar, ap- 
peared in exactly the same condition as a corresponding one placed under 
glass in a vessel free from any abnormal mixture of that ingredient. 

From these, and from the experiments of the preceding year, it might be 
inferred that plants in general are tolerant of a much larger volume of car- 
bonic acid gas than exists in the atmosphere at present; but it did not 
therefore follow, that the amount of carbonic acid decomposed, and of 
oxygen exhaled, would bear any proportion to the quantity with which their 
leaves were brought into contact. 

From several trials indeed which I made as to the per-centage of oxygen 
present in the jar at different stages of the experiment, I was led to infer that 
the amount of the latter was not increased in the degree which might have 
been expected ; but, as a more easy way of determining the same point, I 
introduced a certain number of fresh leaves of an Helianthus, in each case 
exposing exactly the same amount of surface, into jars filled with water con- 
taining different proportions of carbonic acid gas. In No. 1, for instance, the 
proportion of gas to water was only as 1 to 12; in No. 2 as 1 to 6 ; and in 
No. 3 as 1 to 3. Now it was found, that, instead of the oxygen disengaged 
by the leaves keeping pace with the supply of carbonic acid, only 0'7 of a 
cubic inch was given off from No. 3, whilst No. 2 had disengaged 4 cubic 
inches, and No. 1 3*3 cubic inches; and in another experiment only O'l was 
emitted by No. 1 ; 4*5 by No. 2 ; and 2-0 by No. 3, the other circumstances, 
as to time, exposure to light, &c., being in all cases the same. If therefore 
the disengagement of oxygen from leaves be, as is generally admitted, the 
result of their vital action upon the carbonic acid in contact, under the 
stimulus of light, it would follow, that where the carbonic acid exceeds a 
certain amount, that action is in a great degree suspended. 

There is however an experiment of Count Rumibrd's, originally reported 
in the Philosophical Transactions for 1786, and alluded to by one of my co- 
adjutors in these investigations, I mean Mr. Hunt, in his late work entitled 
' The Poetry of Science,' which would seem to imply that the decomposition of 
carbonic acid by plants was not a vital phsenomenon, and consequently could 
not be influenced by any such circumstance as the application of a super- 
abundant portion of this gas to the surfaces of their leaves. 

Count Rumford states, that the property of causing water to emit oxygen in 
the sun, is possessed, not only by living plants, but likewise by threads of silk, 
by wool, and even by spun glass ; in which case the decomposition of carbonic 
acid would seem to be simply the effect of light, the plant merely serving, by 
the surfaces it exposes to the water, to disengage from it, more rapidly than 
would otherwise happen, that oxygen which had been obtained without its 
direct agency. 

On repeating this experiment, however, I found, as might have been anti- 
cipated, that at first no such effect took place when wool, cotton, silk, or spun 
glass were introduced into the water, but that after some days it occurred 
abundantly in every one of these cases — the disengagement of the gas 
however being always coincident with the appearance in the liquid of green 
confervae, to the action of which doubtless this decomposition of carbonic 
acid was to be attributed. 



INFLUENCE OF CABBONIC ACID GAS ON HEALTH OP PLANTS. 59 

Accordingly the process went on, whether fibrous substances were placed 
in the water or not, although in the latter case somewhat less rapidly, the 
presence of such bodies serving to disentangle the particles of" gas from their 
adhesion to the water more easily than would happen otherwise- 
There cannot therefore be a doubt, that the common opinion, which regards 
the emission of oxygen from the surfaces of leaves, whether placed in water 
or in air, as a vital phaenomenon, is the correct one, and hence it is quite con- 
sistent with analogy, that, as we have already seen, some one proportion of 
carbonic acid in the air should be more favourable to the exercise of this 
function, than any other one more considerable in amount would prove. 

I was therefore encouraged to proceed in my inquiry as to the quantity of 
carbonic acid contained in air, which was decidedly prejudicial to the health 
of ferns. 

With that view specimens of the same five species as before were selected 
for experiment, and these were placed under the jar which contained about 
2800 cubic inches of air cut off from the external atmosphere by water. To 
this air 1 per cent, of carbonic acid was at first added, and a daily increase 
to the same amount in the quantity present was kept up, until the propor- 
tion reached 20 per cent. This same quantity was then maintained in the 
jar for twenty days, by successive additions to compensate for the ascertained 
amount of leakage, now found to be inconsiderable, and the appearance of 
the plants was from time to time examined and noted. 

It was not till the 13th day that any sensible alteration for the worse was 
perceptible, when we observed, that in Pteris longifolia the fronds had be- 
come very brown ; in Nephrodium 7nolle and in Gymnogramma chrysophylla 
two or three of the lower fronds showed signs of yellowness ; that those of 
the Adiantum looked in general very sickly, but that Pteris serrulata did 
not appear injured. The experiment was however continued seventeen days 
longer, when it was found, for the first time, that the amount of carbonic acid 
present in the jar, as ascertained in the usual way by potass, exceeded what 
had been added ; proving more decisively than before, that decay had com- 
menced. The plants were accordingly taken out, and the following notes 
respecting their condition were entered in the Minute-Book. 

Pteris longifolia. — All the old fronds are now dead, but the vitality of the 
rhizoma is not destroyed, for young fronds are putting out, and appear at pre- 
sent to be healthy. 

Pteris serrulata even now appears but slightly damaged, its fronds being 
only more yellow than is natural. 

Nephrodium molle seems in the same condition nearly as Pteris longi- 
folia. 

Gymnogramma chrysophylla. — Its old fronds slightly damaged and yellow, 
but young ones are putting out. 

Adiantum cuneatum. — AH the fronds have died down. 

Thus it appears that this large amount of carbonic acid, even if gradually 
added, would in time prove fatal to plants of the above description, although 
operating upon them with various degrees of intensity, and apparently not 
exerting any specific influence upon the stem and roots. 

That the effect however was attributable; not to tiie diminution in the pro- 
portion of oxygen consequent upon the addition of so large an amount of 
carbonic acid, but to something positively deleterious in the latter gas itself, 
was inferred, by exposing the plants to air impregnated with 'iO per cent, of 
hydrogen, which in the course of ten aays appeared to exert no sensible in- 
fluence upon their health. 

There did not appear to be any very material difference in the action of 



60 REPORT — 1849. 

carbonic acid upon plants, whether it were suddenly or gradually introduced ; 
for when I exposed the same ferns to air into which 20 per cent, of carbonic 
acid had been added all at once, it was not till the 9th day that any change 
in their appearance was perceptible, and then only in three of the specimens ; 
Pteris serrvlata and Adiantum cuneatum being scarcely, if at all affected. 

However, on the 16th day the influence of the gas was manifest upon all 
except Pteris serrulata; the per-ccntage of carbonic acid was found to exceed 
that which had been added from without, and the condition of the ferns ge- 
nerally was rather more unhealthy and faded than it had been in the fore- 
going experiment, where the gas had been added in successive doses*. 

So much for this part of the investigation, which seems to be in a manner 
prefatory to the one which may be regarded as the more immediate object 
aimed at by the Association in suggesting these researches, that being, whether 
a larger amount of carbonic acid than is present in our atmosphere would 
increase the vigour, and stimulate the growth, of the tribes of plants which 
are most connected with the fossil remains found in the coal formation. 

With reference to this latter question, I am not so far advanced towards its 
determination as might have been desired. 

During the last five weeks Ferns and Lycopodiums have been living in an 
atmosphere containing constantly 5 per cent, of carbonic acid, whilst corre- 
sponding specimens have been placed under similar circumstances, except that 
the abnormal amount of carbonic acid above stated was absent from the air 
of the jar. In both instances the Lycopodiums continue up to this time in 
perfect health, but it must be confessed that the Adiantum cuneatum &ndjla- 
gelliforme which have been subjected to carbonic acid appear less thriving 
than the corresponding plants not so treated. 

It must be remarked moreover, that the per-centage of gas within the former 
jar has been increased to 5^ per cent., the additional ^ per cent, being attri- 
butable to the diseased state of some of the fronds. 

The experiment however shall be continued for a longer period until more 
decisive results have been arrived at. 

But supposing it to be ascertained that ferns will exist in air containing 
5 per cent, of carbonic acid, it still remained a question, whether the animals 
that lived at the same period could have resisted the poisonous influence of 
so large a proportion of this gas. 

In the coal formation, properly so called, MoUusca and Fish appear to be 
the animal remains principally detected, and the difference between the struc- 
ture of existing species, and of those which were in being at so remote a 
period as the one alluded to, may be urged, as an objection to the idea of 
extending to the latter any inferences that might be deduced from experiments 
instituted upon the former. 

Nevertheless as in so fundamental a function as that of respiration, a si- 
milar law pervades all the individuals belonging to the same great natural 
group at the present time, as for instance, what is true in this respect con- 
cerning the lowest in the scale of Mammalia, holds good likewise with cer- 
tain modifications with regard to the highest, it may not be illogical to presume, 
that the difference as to time would not create any radical change in the re- 
lations of a particular class of animals to carbonic acid, and in their suscep- 
tibility to its influence. 

* I do not find that ferns suflFer from confinement in large jars ; and at all events, as the 
circumstances were precisely the same in the two cases, with the exception of the presence 
or absence of this excess of carbonic acid, the difference in the appearance of the specimens 
seems clearly referable to the latter cause alone. 



Il 



INFLUENCE OF CARBONIC ACID GAS ON HEALTH OF PLANTS. 61 

With reference to the proportion of carbonic acid which water would abstract 
from air containing diffused through it so large an amount as 5 per cent, of 
this gas, the principles upon which such a problem may be determined have 
been long ago clearly laid down by Dr. Dalton. 

As neither carbonic acid, oxygen, or nitrogen are retained in water by vir- 
tue of any chemical affinity, but simply in the ratio of their respective elas- 
ticities, it follows that the quantity of these gases present in it will be regu- 
lated by the amount of each existing at the time in the superincumbent air. 

We know by experiment, that water would retain nearly about its own vo- 
lume of carbonic acid ; 0*65 of its volume of oxygen ; and 0*42 of nitrogen ; 
under the pressure of an atmosphere consisting wholly of the gas so retained. 

If therefore we suppose the atmosphere in former times to have consisted 
of carbonic acid 5 per cent, and of common air, maintaining its present con- 
stitution, 95, that is, of — 

Nitrogen 76 

Oxygen 19 

Carbonic acid 5 

the quantity of each gas retained by a volume of water under such circum- 
stances would be as follows : — 

Nitrogen '03192 

Oxygen -01235 

Carbonic acid -05300 



-09727* 
Water therefore under an atmosphere of this constitution would still con- 
tain nearly as much oxygen as it does at present, and not more than "05, or 
j\j, of its volume of carbonic acid, so that the condition of the gas expelled 
from the water would be such, as to consist in 100 parts of — 

Carbonic acid Si'S 

Nitrogen 32-9 

Oxygen 12-6 

100-0 
Now I am enabled to prove, that a much larger proportion of carbonic acid 
than that supposed may exist in water without affecting the health of fish at 
the present time. On one occasion indeed I agitated some river water in a 
closed vessel with a mixture of common air and carbonic acid, in the propor- 
tion of 1300 of the former to 100 of the latter, or in an atmosphere containing 
7 or 8 per cent, of carbonic acid, and found that a number of Minnows intro- 
duced into the water so impregnated died within twenty-four hours, although 
29 cubic inches were found by experiment to have taken up only 1 cubic 
inch of carbonic acid, which is in the ratio of 2-5 per cent. 

Nevertheless it was afterwards found by a number of experiments, that 

other fish, such as Perch and Roach, would live in water which contained from 

5 to 10 per cent, of carbonic acid, the larger of which quantities Avould be 

nearly double that which has been shown to be taken up by water under a 

-pressure of 5 per cent, of the latter gas. On the other hand, where the 

* As will appear by the following equation : — 

Nitrogen -yGx 042 = -03192 

Oxygen -IQx 065 = -01235 

Carbonic acid , •05x1-06 = -05300 

•09727 



62 REPORT — 1849. 

quantity present might be estimated at 13 per cent, as compared to the 
volume of water, all the fish experimented upon speedily perished. 

Nor was this merely the case with freshwater species, for I have had an 
opportunitj' within the last fortnight of repeating the same experiments at 
Ryde on certain sea-fish obtained oflF that coast. The species operated upon 
were those called Golden Maid (Labnis), two sorts of Pipe-fish (Syngnathus), 
Rock-fish {Gobius )iiger). Bull-fish {Cottus scorpius), and Flounder (^Platessa 
flesus). Of these the Pipe-fishes and the Flounder remained alive for many 
hours in a tub of salt water containing 5 per cent, of carbonic acid, nor did 
they appear to suffer in consequence. When the amount was equal to 10 per 
cent., the Golden Maid (Labrus) was almost instantly affected, as were also 
the Pipe-fishes above operated upon. 

Although therefore the difficulty of keeping sea-fish long alive in small 
quantities of salt-water, after they have been removed from their natural 
element, renders it more difficult to arrive at satisfactory results with them 
than with freshwater species, I think myself upon the whole warranted in 
concluding, that both kinds are equally tolerant of the smaller amount of car- 
bonic acid, and alike susceptible of the poisonous influence of the larger. 

Supposing however no error to exist in the calculation I have made above 
as to the amount of carbonic acid present in the water to which the minnows 
had been subjected, it will follow that whilst 5 per cent, is innoxious to some 
fish, 3 per cent, is noxious to others, and that the power of resisting its dele- 
terious influence differs in different species. Nevertheless there seems reason 
for supposing, that an amount of carbonic acid in the atmosphere considerably 
larger than that which exists at present, would not communicate to the waters 
of the sea and rivers properties incompatible with the life of many fish. 

Although reptiles are not supposed to have existed generally at so early a 
period as that of the carboniferous formation, yet as saurians have been de- 
tected in the coal-beds of Greensburg in Pennsylvania, and in those of Saar- 
bruck near Treves*, which are regarded as belonging to the same epoch, and 
as they made their appearance so abundantly in that which comes next to it in 
point of antiquity, it appeared worth while to ascertain what power of resisting 
the influence of carbonic acid might be possessed by the tribes now in being 
which belong to the same class of animals. 

With reference however to this department of the inquiry, the experiments 
hitherto made by myself are far from numerous : I have however found, that 
frogs introduced under a bell-glass containing 5 per cent, of carbonic acid 
gas, appeared not to suffer, although they were killed when its proportion 
amounted to 10 per cent. Similar results were also obtained in experimenting 
upon newts ; so that it would seem, as if, in accommodation to those arrange- 
ments of nature which were calculated to impart a greater luxuriance to the 
vegetation of the period alluded to, and to bring about during its continuance 
a larger accumulation of carboniferous matter, the lower tribes of animals, 
which at that time alone occupied the earth, were rendered less susceptible of 
the injurious influence of carbonic acid, than the higher orders subsequently 
created are found to be. 

In conclusion then I may remark, that the general tenor of these experiments, 
so far as they have as yet gone, justifies us in inferring, that there is nothing 
in the organization of those plants and those animals of the present day, which 
appear most nearly allied to such as were in existence during the carbonife- 

* See Lyell's Travels in America, 2nd Series. 



ON THE HKAT OP COMBINATION. 63 

rous epoch, or even somewhat subsequently to that period, militating against 
the probability, that a larger amount of carbonic acid may have been present 
in the atmosphere, and diifused through the waters of the sea and rivers, 
than is found, either in the one or in the other, at the present time; nor is 
there anything to prevent us from imagining, that the absorption of carbon by 
vegetables, and the consequent rapidity of their growth, may, at least within 
certain limits, have borne some proportion to the greater amount of carbonic 
acid assumed to have been present at earlier periods in the history of our 
globe, although whether this be actually the case, is a point which I hope to 
be able hereafter to settle more to my satisfaction, as well as to report the 
results arrived at on some future occasion. 



Report on the Heat of Combination, 
By Thomas Andrews, M.D., F.R.S., M.R.I.A. 
There are few molecular changes in the condition of matter which are 
not accompanied by the evolution or absorption of heat. The quantity of 
heat which is thus set free or absorbed, bears always a definite relation to 
the amount of the mechanical or chemical action, and its determination in 
each particular case is a problem of considerable interest as affording a 
measure of the forces in action. If we consider the great number of phseno- 
mena, mechanical, electrical and chemical, among which the production of 
heat forms the only bond of connexion which has hitherto been clearly 
ascertained, although there may be strong grounds for suspecting them to be 
only modified forms of the action of the same force, the importance of inves- 
tigations of this kind to the future progress of physical science will become 
at once apparent. 

The object of the present Report is to give a general view of the actual 
state of knowledge on the subject of thermo-chemistry, under which we may 
conveniently include a description of the thermal effects that occur in che- 
mical actions of every kind. A few new experiments will be described in 
their proper places. These will be given in some detail, but when referring 
to experiments already published, all numerical quantities will, as far as pos- 
sible, be avoided. 

Before entering upon the consideration of chemical combinations and de- 
compositions properly so called, it may be useful briefly to refer to the ther^ 
mal changes which accompany solution. The earlier experiments on this 
subject having been made solely with the object of discovering frigorific 
mixtures, do not furnish quantitative measures of any scientific value. But 
of late years the inquiry has been pursued in a more useful way by Gay- 
Lussac, Thomson, Karsten, Chodnew and Graham. The salts examined have 
been chiefly the soluble sulphates, nitrates and chlorides, and the solvents 
pure water and saline and acid solutions. The principal results of these in- 
vestigations I have endeavoured to express in the following propositions : — 

1. The solution of a crystallized salt in water is always accompanied by 
an absorption of heat. 

2. If equal weights of the same salt be dissolved in succession in the same 
liquid, the heat absorbed will be less on each new addition of salt. 

■ 3. The heat absorbed by the solution of a salt in water holding other salts 
dissolved, is generally less than that absorbed by its solution in pure water. 

i. The heat absorbed by the solution of a salt in the dilute mineral acids, 
is generally greater than that absorbed by its solution in water. 



64 REPORT — 1849. 

As the subject is of great extent and the inquiry has hitherto embraced 
only a small number of cases of solution, it is not unlikely that some of these 
conclusions will require hereafter to be modified. From some experiments 
by Graham on the solution of salts belonging to certain isomorphous groups, 
there is reason to suspect the existence of a connexion between isomorphism 
and the absorption of heat in solution. 

The foregoing remarks apply only to the solution of crystallized salts. If, 
however, we take a salt Avhich crystallizes with water and make it anhydrous 
before solution, the thermal results will be altogether different. The anhy- 
drous salt, when added to an excess of water, will first combine with its ordi- 
nary equivalent of water of crystallization, and the new compound will then 
dissolve. The change of temperature observed is therefore a complex quan- 
tity arising from the heat of combination due to the union of the anhydrous 
salt with water, and the heat absorbed by the solution of the hydrous salt. 
From a comparison of the results obtained on dissolving tiie same salt in the 
anhydrous and hydrous states, Graham has endeavoured to deduce the amount 
of heat due to the combination of the dry salt with its water of crystallization. 
According to his experiments, the sulphates of water, copper and manganese, 
disengage the same quantity of heat in combining with the first atom of 
water. The sulphates of magnesia and zinc also disengage equal quantities 
of heat in their complete hydration. The same simple relation is not however 
observed to hold between the quantities of heat evolved in the complete hy- 
dration of the first set of salts, or in the combination of the second set with 
the first atom of water. Neither does it apply to the other sulphates of the 
magnesian serie?. 

None of the experiments hitherto published furnish all the requisite data 
for calculating with precision the absolute quantities of heat set free or 
absorbed in these cases of chemical action. The weights of the water and of I 
the salt are given, and sometimes the weight and form of the vessel, and the 
material of which it is composed ; but these data are not sufficient to enable 
us to deduce the true numbers from the observed increments or decrements 
of temperature. Knowing the weight and composition of the containing 
vessel, we may, it is true, calculate its thermal value in water. But other 
corrections, such as those for the heating and cooling influence of the sur- 
rounding air, can only be ascertained by special experiments performed 
under similar conditions to the original observations. Neither have any ex- 
periments of sufficient accuracy been made to determine the specific heats of 
the solutions formed. 

To complete an investigation which would furnish all these elements, would 
be a work of very great labour, and will probably scarcely be undertaken till 
our instruments and means of observation are greatly improved. As a first 
step to such an inquirj', I may here describe a few preliminary experiments 
on the specific heats of some saline solutions, and on the quantities of heat 
absorbed in the solution of successive portions of the same salt. 

To obtain results approaching to accuracy in experiments on the specific 
heats of saline solutions is extremely diflicult, as the errors of experiment are 
often of nearly the same order of magnitude as the whole differences to be 
observed. Tlie corrections for the cooling and heating action of the air and 
for the effects of radiation, cannot be estimated with any certainty by the ap- 
plication of general formulas founded on experiments made at a different 
time* ; and the most careful examination of the calibre of the thermometer 

* If the vessel be uncovered, changes in the hygrometric state of the atmosphere produce 
a very marked influence on the rate of cooling, when the excess of temperature above the air 



ll 



ON THE HEAT OF COMBINATION. 65 

tube will fail to render different parts of the scale accurately comparable with 
one another to a five-hundredth part. The general method pursued in the 
determination of the following specific heats was the same which I described 
some years ago*; but to avoid the uncertainties just referred to, alternate 
experiments were made with pure water and with the solution, under condi- 
tions a3 nearly as possible identical, and these were repeated till accurate 
means were obtained. By this mode of operating, a very great degree of 
precision may be given to experiments of this kind. 

The only salts whose solutions have yet been examined are the nitrate of 
potash, the nitrate of soda and the chloride of sodium. They were all chemi- 
cally pure. The density of each solution compared with water at the same 
temperature was also determined. 

The first solution of nitrate of potash contained for every 100 parts of 
water 25'29 parts of the salt. The thermal values of the thermometer with 
large reservoir described in the paper already referred to, in terms of this 
solution and of water, were found in alternate experiments to be — 
Solution I. Water. 

5044. 4095 

5047 4107 

5050 4116 

Mean 5047 4106 

The temperature of the air during these experiments varied only from 
18° C. to 18--5 C. 

The second and third solutions contained respectively 12*645 and 6"322 
parts of nitrate of potash for 100 parts water. Air from 18°*5 to 18°*9. 
Solution II. Solution III. Water. 
4600 4393 4118 
4620 4387 4105 
4605 4385 4108 
4610 

Mean 4610 4387 4110 

From these data the specific heats of these solutions at the temperatures at 
which the experiments were performed, as compared with water at the same 
temperatures, may be easily computed. I have given them in the following 
table, as also the specific gravities of the liquids. 

I. II. III. 

Specific heat 0-81 35 0'8915 0-9369 

Specific gravity .. 1-1368 1-0728 1-0382 

The solutions of nitrate of soda contained 42-49, 21-245 and 10-622 parts 
respectively of nitrate of soda for 100 parts of water. The temperature of 
the air ranged from 17°-5 to 18°-8 during these experiments. 

Solution I. Water. Solution II. Water. Solution III. Water. 
5261 4107 4775 4116 4499 4116 

5234 5117 4782 4098 4498 4098 

5247 4119 4787 4100 4488 4100 

Mean 5247 4114 4781 4105 4495 4105 

I. 11. III. 

Specific heat 0-7838 0-8585 0-9131 

Specific gravity 1-2272 1-1256 1-0652 

amounts only to a few degrees ; and even in a close apartment the increased agitation of the 
!ur on a windy day sensibly increases the rate of cooling. 

* Philosophical Transactions for 1844, p. 34. 
1849. F 



66 



REPORT — 1849. 



Of chloride of sodium two solutions were examined, the first containing 
29"215, the second 14'607 chloride of sodium for 100 water. The air was 
nearly steady between 17°'9 and 18°. 

Solution II. Water. 

4740 4111 

4733 4106 
4731 





Solution I. 


Water. 




5107 


4111 




5127 


4106 




5128 




Mean. 


..5121 


4108 



4735 



Specific heat 0-8018 

Specific gravity 1*1724 



4108 
II. 
0-8671 
1-0942 



It may be not uninteresting to compare these numbers with those deduced 
by calculation from the specific heats of the salts in the dry state. The latter 
have been made the subject of experiment by Avogadro and Regnault, but 
their results do not agree well with each other. I have adopted Regnault's 
numbers in my calculations. 



Solution. 




Specific heat 


Mean spec, heat of 






by experiment. 


dry salt and water. 


Nitrate of potash 


1. 


0-8135 


0-8463 


j> » 


2. 


0-8915 


0-9145 


>> » 


3. 


0-9369 


0-9566 


Nitrate of soda 


1. 


0-7838 


0-7847 


»j )> 


2. 


0-8585 


0-8736 


5) >J 


3. 


0-9131 


0-9307 


Chloride of sodium 


1. 


0-8018 


0-8224 


„ „ 


2. 


0-8671 


0-9000 



It is obvious that the specific heat of the solution is, in every instance, less 
than the mean of the specific heats of its component parts, and that serious 
errors would be committed, if we should attempt to calculate on this principle 
of the thermal values of solutions which may be formed in the course of our 
experiments. 

I have made a short series of experiments on the quantities of heat 
absorbed during the solution of nitrate of soda and of nitrate of potash, when 
added in successive portions to the same liquid. The results fully confirm 
those previously obtained by Graham, but as the experiments were only pre- 
liminary trials to a more extended investigation, it is not necessary to describe 
them in detail. I may briefly state, that on dissolving 12-22 grammes of ni- 
trate of soda in 250 grammes of water and repeating the experiment with 
each new solution, till the water was nearly saturated, the following decre- 
ments of temperature were found : — 



1. 


2-80 C. 


6. 


1-60 C 


2. 


2-43 


7. 


1-47 


3. 


2-11 


■ 8. 


1-39 


4. 


1-89 


9. 


1-33 


5. 


1-75 


10. 


1-27 






11. 


1-21 



By the aid of the specific heats already determined, and knowing the thermal 
value of the vessel in which the experiments were performed (4-3 grms.), I 
have calculated for experiments 1 , 4 and 9 the following numbers, which ex- 



ON THE HEAT OF COMBINATION. 67 

press the degrees Centigrade through which one part of water would be raised 
by the heat absorbed in the solution of one part of the salt. 
1. 2. 3. 

590 407 309 

On dissolving 7*99 grms. nitrate of potash in 250 grms. water and repeating 
the operation as before, the successive decrements of temperature observed 
were, — 

1. 2°65 C. 5. 2-06 C. 

2. 2-49 6. 1-97 

3. 2-34. 7. 1-87 

4. 2-22 8. 1-75 

Combination of Sulphuric Acid with Water In an elaborate memoir 

on thermo-chemistry, which was published in PoggendorfF's 'Annalen,' Hess 
made the first systematic attempt to reduce the quantities of heat disengaged 
in the formation of the hydrates of sulphuric acid to definite laws. His ex- 
periments were made by two distinct methods, which however did not give 
exactly the same results. In the first or indirect method of operating, equi- 
valent quantities of SO3, SO3 HO, SO3 2HO, &c., were respectively mixed 
with a large excess of water and the increments of temperature observed in 
each case. The difference between the increments observed on mixing any 
two compounds with water, was assumed to correspond to the heat due 
to the combination of the first compound with the number of equivalents of 
water necessary to convert it into the second. Thus, if SO3 HO added to 
X HO gave a units of heat, and SO3 3H0 added to the same x HO gave b units, 
a—b was supposed to represent the number of units which would be obtained 
on combining SO3 HO and 2H0. In the second, or direct method, each 
compound was combined with the quantity of water exactly required to con- 
vert it into the succeeding compound, and the heat measured by observing 
the increment of temperature of a determinate quantity of water surrounding 
the vessel in which the combination took place. These experiments have 
since been repeated by Graham, Abria, and Fabre and Silbermann, but their 
results do not generally agree with the statements of Hess. 
_ The fundamental principle laid down by the latter is, that there exists a 
simple relation between the numbers which express the quantities of heat set 
free in the formation of the successive hydrates of sulphuric acid. If we de- 
signate by 2 a the heat disengaged in the combination of SO3 HO with HO, 
then, accordmg to Hess, the heat set free in the formation of the other hy- 
drates will be 

SO3-I-HO 8a 

SO,HO + HO 2a 

S03 2H04-HO a 

SO33HO-I-3HO a 

SO36HO+XHO a. 

In an early part of his memoir, Hess gives 38*85 for the value of a, but 
this he afterwards changes to 46-94, still maintaining however the accuracy 
of the ratios. It is difficult to see how this can be correct. The only expe- 
riment described by Hess on the combination of the anhydrous acid with 
water gave the number 305, which bears to 46-94, not the ratio of 8 : 2, but 
nearly that of 6-5 to 2. Abria obtained a still lower number for the combi- 
nation SO3 with HO. There can therefore be little doubt, if the experiments 
may be relied on, that the first ratio is too high. It remains to be seen how 
far the others have been confirmed by subsequent investigations. 

f2 



68 REPORT 1849. 

The multipliers of a for the three latter combinations given in the preceding 
table are, according to Graham's experiments, 0*72, 1"35 and 1*18. These 
numbers agree with Hess's statement only so far as to indicate that the heat 
evolved in the combination of SO3 HO with HO is nearly the same as that 
evolved in the combination of SO, 2H0 with 4H0. 

The experiments of Abria were performed by the direct method and with 
a similar apparatus to that employed by Hess. Adopting the views of Hess as 
to the quantities of heat in the cases of combination being in simple relations 
to one another, he arrives nevertheless at very different numbers for the ratios. 
In the next table I have given Abria's theoretical whole numbers, as also the 
exact numbers which result from his experiments. 

Theory. Experiment. 

SO3 + HO 6a 6-02a 

SO3HO + HO 2a 2-OOa 

SO32HO + HO.. .. a 0-95a 

SOjSHO + HO.... ia O'BIa 

SO3 4H0 +- HO fa 0-35a 

SO35HO + HO.... ^ 0-22a 

In the three latter cases, the simple relations in the second column are 
scarcely borne out by the experimental numbers. The only agreement with 
the ratios given by Hess is in the combination SO3 2H0 with HO, which, 
according to both experimenters, sets free exactly half as much heat as the 
combination SO3HO with HO. The value of a, given by Abria, is 39*33. 

The latest experiments on this subject are those of Fabre and Silbermann, 
from which I have calculated the following multipliers for a : — 

SO3HO + HO 2-OOa 

SO3 2H0 + H0 0-93a 

SO33HO + HO 0-53a 

SO34.HO + HO 0-32« 

SO35HO + HO 0-26a 

Hess has also attempted to express by simple multiple relations the quan- 
tities of heat disengaged in the formation of the hydrates of nitric acid, but 
for the details of his results I must refer to the original memoir. 

Combination of Acids and Bases. — In the same memoir Hess describes an 
extensive set of experiments on the heat evolved during the union of certain 
bases with acids of different degrees of concentration. These experiments 
serve to illustrate the general principle, that in the formation of a chemical 
compound the heat developed is a constant quantity, being the same in 
amount, whether tiie combination takes place directly at one time or in- 
directly at repeated times. Thus he finds that on neutralizing an aqueous 
solution of ammonia with sulphuric acid, containing one, two, three and six 
atoms of water, there is a different development of heat in each case ; but by 
adding to the results found by experiment in the three latter cases the quan- 
tities of heat due to the combination of the monohydrated acid, with one, 
two and five atoms of water respectively, the same number is obtained in each 
ease as in the direct combination of the monohydrated acid itself. This 
principle is correct, but it is almost self-evident and scarcely required so 
elaborate a proof. 

The bases examined by Hess were potash, soda, ammonia and lime, which 
he combined in different ways with the sulphuric, nitric and hydrochloric 
acids. The conclusion at which he arrives is, that the same acid in combining 
with equivalents of different bases produces the same quantity of heat, but at 
the same time he expresses some doubt as to the applicability of this principle 



ON THE HEAT OF COMBINATION. 69 

to all similar cases of combination. Indeed his own experiments with lime 
and ammonia do not accurately agree with it ; I refer particularly to his ex- 
periments with ammonia, which, when properly interpreted, appear to me to 
prove clearly that that base in combining with acids developes less heat than 
potash or soda, although I am aware that Hess himself has drawn from them 
a different conclusion. 

About the time of the publication of the first part of Hess's memoir, I had 
completed an investigation of the same subject, but instead of employing strong 
solutions of the acids and bases, I diluted all the liquids largely with water 
previous to examining their thermal reactions. In this way I hoped to avoid 
the complex effects that arise when successive combinations and decomposi- 
tions of different kinds occur in the same chemical action, and the result 
fully realized my anticipations. The general conclusion deduced from this 
investigation may be briefly expressed, by stating that the heat de9eloped during 
the union of acids and bases is determined by the base and not by the acid. 
The following special laws will be found to comprehend the greater number 
of cases of chemical action to which the foregoing principle can be made to 
apply. 

1.* An equivalent of the same base, combined with different acids, produces 
nearly the same quantity of heat. 

2. An equivalent of the same acid, combined with different bases, produces 
different quantities of heat. 

3. When a neutral salt is converted into an acid salt by combining with 
one or more equivalents of acid, no disengagement of heat occurs. 

4-. When a double salt is formed by the union of two neutral salts, no dis- 
engagement of heat occurs. 

5. When a neutral salt is converted into a basic salt, the combination is 
accompanied by the disengagement of heat. 

6. When one and the same base displaces another from any of its neutral 
combinations, the heat evolved or absorbed is always the same whatever the 
acid element may be. 

As some of the bases (potash, soda, barytes and strontia) form what we 
may perhaps designate an isothermal group, such bases will develope the 
same, or nearly the same heat in combining with an acid, and no heat will be 
developed during their mutual displacements. 

These laws are not intended to embrace the thermal changes which occur 
during the conversion of an anhydrous acid and base into a crystalline com- 
pound. The steps by which such a conversion is effected are generally very 
complicated, and involve successive combinations and decompositions. We 
cannot combine, at ordinary temperatures, a dry acid and a dry base ; and 
when combination takes place in presence of water, hydrates of the acid and 
base are first formed, which are afterwards decomposed, and the crystalline 
salt finally obtained is sometimes anhydrous, sometimes combined with water. 
To expect simple results where so many different actions must produce each 
its proper thermal effect, would be altogether vain, and to introduce the con- 
sideration of some of these actions without the whole would only render the 
numbers empirical. In the experiments from which the foregoing laws were 
deduced, the acids and bases before combination, and the compounds after 
combination, were as nearly as possible in the same physical state. The only 
change which occurred was the combination of the acid and base, and the 
heat evolved must therefore have arisen from the act of combination. Such 
changes of temperature as are produced by solution are not in any way con- 
cerned in producing these thermal effects, as none of the reacting bodies 
assumed at any time the solid state. The insoluble bases form, it is true, an 



70 REPORT — 1849. 

unavoidable exception to this statement, and in the experiments with them, 
the results would require to be corrected for the heat due to the change of 
the base from the solid to the fluid state. As this correction, however, al- 
though unknown, must be a constant quantity for the same base, it would 
not, if applied, interfere with the direct proof of the first law. 

In an inquiry of this kind, it is important, while endeavouring to generalize 
the results of experiment, to point out at the same time the differences which 
occur in particular cases between those results and the numbers deduced from 
the theory. In the whole range of the science of heat, scarcely a single 
general principle has yet been discovered which is strictly in accordance 
with all the results of experiment ; and from the application of improved me- 
thods of experimenting, discrepancies of this kind have of late years been 
found to exist where they had not before been suspected. 

In the original experiments from which the first of the foregoing laws was 
deduced, the mean heatdeveloped by the nitric, phosphoric, arsenic, hydrochlo- 
ric, hydriodic, boracic, chromic and oxalic acids being 6°"61, the greatest de- 
viation from the mean on either side amounted only to 0°*15 ; and a similar 
remark may be made with respect to the combinations of soda, barytes and 
ammonia. On the other hand, sulphuric acid disengaged about 0°*7 more^thau 
the mean quantity, and the citric, tartaric and succinic acids about 0°*5 less. 
To ascertain whether these discrepancies depended on the state of dilution of 
the solutions, I repeated these experiments lately with solutions of only half the 
strength, but although only half the heat was obtained, similar differences 
were still found to exist. If, instead of taking just the quantity of sulphuric 
acid required to neutralize the base, we employ a large excess, the heat given 
out during combination Mill be nearly 0°'2 less, which reduces the anomaly 
presented by this acid to about 0°"5. The sulphurous acid not having been 
formerly examined, I have lately made some experiments on its thermal re- 
lations to the bases, the results of which are very interesting. Although one 
of the feeblest acids, it agrees almost exactly with sulphuric acid in the heat 
developed by its combination with potash. In several carefully conducted 
experiments the increments of temperature did not differ more than 0°*05. 
Combining this with the fact that acids differing so much in composition and 
properties as the nitric, boracic and oxalic, also disengag^e almost exactly the 
same amount of heat in the act of combination, there will, I conceive, be 
little hesitation in attributing the deviations already mentioned to the in- 
fluence of extraneous causes, and in acknowledging the truth of the principle, 
that the heat of couibination depends upon the neutralization or combination 
of the base, and not upon the nature of the acid by which the base is neutral- 
ized. That other causes of change of temperature, of feeble power, do ac- 
tually exist, may be proved by the following fact. If we add an excess of 
sulphuric acid to the neutral solution after combination has taken place, a 
slight fall of temperature, amounting to about 0°'l, will occur; if we make 
the same experiment with sulphurous acid, an increase of temperature of about 
equal amount will be observed, while with oxalic acid there will be no 
thermal change of any kind. Now it is very probable that the same causes 
which produce these slight thermal effects are in operation during the original 
combination of the acid and base, and if so, they would introduce anomalies 
into the quantities of heat then developed. 

There is one important condition, which, as far as my investigations ex- 
tend, requires to be fulfilled in order that the first law may hold good ; viz. 
the acid must have the power of neutralizing the alkaline reaction of the 
bases. It is for this reason that the hydrocyanic, carbonic and arsenious 
acids do not develope the same quantity of heat in combining with potash as 



ON THE HEAT OF COMBINATION. 'Jl 

the other acids. The sparing solubility of the arsenious acid in water pre- 
vents an accurate examination of its thermal reactions ; but on repeated 
trials I obtained 0°*25 F., on combining with it the same quantity of potash 
which under similar conditions gave 0°"34' with nitric acid. Although a 
considerable excess of arsenious acid was taken, as proved by the fact that 
further additions produced no new development of heat, the solution still 
exhibited an alkaline reaction. The same is also well known to be true of 
the hydrocyanic and carbonic acids. In the case of bases, such as the oxide of 
copper, whose salts have all an acid reaction, this criterion will not apply ; 
but the exceptional acids are so few, and their peculiarities so well-marked, 
that they give rise to little difficulty in the experimental investigation. 

The quantities of heat developed by different bases in combining with the 
same acid are so different, that it is unnecessary to refer particularly to the 
proofs of the second law. In this case, neutralizing power has no apparent 
influence on the results, as oxide of silver, which forms salts neutral to test 
paper with the strongest acids, is one of the feeblest bases if measured by its 
thermal power. It developes, in fact, little more than one-third of the heat 
which potash does in combining with the acids. 

The more recent experiments of Graham and of Fabre and Silbermann, 
confirm the accuracy of the facts from which the second and third laws were 
deduced, that no heat is developed on mixing solutions of neutral salts or of 
a neutral salt and acid*. It is difficult however to obtain, as Graham has 
remarked, positive proof of the occurrence of combination, when such solu- 
tions are brought into contact. Fabre and Silbermann indeed are of opinion 
that acid salts cannot exist in the state of solution. 

Double Decompositions. — When solutions of two neutral salts are mixed 
and a precipitate formed from their mutual decomposition, there is always a 
disengagement of heat, which, though not considerable, is perfectly definite 
in amount. It does not altogether arise from the components of the pre- 
cipitate having changed from the fluid to the solid state — as it is not always 
the same for the same precipitate — but it is chiefly connected with the latent 
heat of the precipitate. If the latter contains water of crystallization, the 
heat given out is much greater than when an anhydrous precipitate is formed. 
Experiments of this kind appears at first view to be extremely simple, but it 
is often difficult to obtain exact results, from the length of time during which 
the heat continues to be disengaged, even Avhen the combination is aided by 
brisk agitation. 

The precipitation of the salts of barytes and lead by a soluble sulphate 
appeared to present favourable conditions for investigation, and accordingly 
I made an extensive set of experiments with these classes of salts. This is 
indeed the only part of the inquiry which I have been able to complete. A 
few other examples of double decomposition will however be noticed. 

Chloride of Barium and Sulphate of Magnesia. — Of chloride of barium 
carefully purified and dried immediately before the experiment at a low red 
heat, 16"94< grms. were taken in each experiment, equivalent to 19'00 grms. 
sulphate of barytes. The weight of sulphate of magnesia (dry) was 10'3 grms., 
which is a little more than sufficient to decompose completely the chloride of 
barium. The entire weight of the water employed to dissolve the salts was 
234 grms., of which one-third was taken to dissolve the sulphate of mag- 
nesia, and two-thirds to dissolve the chloride of barium. The solutions were 
contained in vessels of thin copper, the smaller of which, when filled with its 

* Slight changes of temperature may however occasionally be detected ; but in some cases 
a development, in others, an absorption of heat occurs. These thermal eflfects evidently arise 
from causes altogether distinct from those which produce the combination of acids and bases. 



72 REPORT 1849. 

solution, floated in the larger, and could be rapidly rotated, so as to produce 
in a short time a perfect equilibrium of temperature throughout the whole 
apparatus. The thermometer attained a maximum about 8' after the solutions 
were mixed. I have elsewhere indicated the precautions to be taken in 
such experiments, and shall therefore not refer to them here. In the fol- 
lowing statements, I have given the temperature of the air, the increment 
actually observed in Centigrade degrees, and the number of degrees through 
which 1 grm. of water would be raised by the precipitation of 1 grm. and 
1 equiv. (oxygen = 1) of the precipitate. In calculating the latter numbers, 
all the usual corrections were applied to the observed increments of tem- 
perature : — o o 

Temperature of air 18*3 14;"4; 

Increments observed 1*95 1'96 

Heat for 1 grm. BaO, SO3 25-4. 25-2 

Heat for 1 equiv. BaO, SO3 . . 368-9 

Chloride of Barium and Sulphate of Soda. — The same weight of chloride 
of barium taken as before, and an equivalent weight of sulphate of soda. 

Temperature of air 20-2 18-7 

Increments observed 1*57 I'S.** 

Heat for 1 grm. BaO, SO3 , . . . 20-4 20" 1 

Heat for 1 equiv. BaO, SO3 . . 294-5 

Chloride of Barium and Sulphate of Zinc. 

o o 

Temperature of air 197 19*6 

Increments observed 1-69 1*72 

Heat for 1 grm. BaO, SO3 . . . . 22-2 22-4 

Heat for 1 equiv. BaO, SO3 . . 325-1 

Chloride of Barium and Protosulphate of Iron. 

o 

Temperature of air IS'S 

Increment observed 1*99 

Heat for 1 grm. BaO, SO, 25-6 

Heat for 1 equiv. BaO, 863 373-2 

Chloride of Barium and Sulphate of Copper. 

o o 

Temperature of air 17-5 17-6 

Increments observed 1-85 1*85 

Heat for 1 grm, BaO, SO3 24-7 24-6 

Heat for 1 equiv. BaO, SO3 . . 359-4 

Chloride' of Barium and Sulphate of Ammonia. 

o o 

Temperature of air 11-3 ll-l 

Increments observed 1-85 1-84 

Heat for 1 grm. BaO, SO3 .... 24-2 24-1 

Heat for 1 equiv. BaO, SO3 . . 352-1 

Nitrate of Barytes and Sulphate of Magnesia. — As the nitrate of barytes 
is sparingly soluble in water, 10-6 grms. only were taken, which is equivalent 
to half the quantity of chloride of barium used in the foregoing experiments. 
The other salts were reduced in the same proportion. 

00 

Temperature of air 13*9 14-4 

Increments observed 0*82 0-82 

Heat for 1 grm. BaO, SO3 22-2 21-2 

Heat for 1 equiv. BaO, SO3 .. 316-4 



ON THE HEAT OF COMBINATION. 73 

Nitrate of Barytes and Sulphate of Soda. 

o 

Temperature of air 14*4i 

Increment observed 0*75 

Heat for 1 grm. BaO, SO3 20-5 

Heat for 1 equiv, BaO, SO3 298-9 

Nitrate of Barytes and Sulphate of Zinc. 

o o 

Temperature of air 13"9 14*1 

Increments observed 0"83 0*83 

Heat for 1 grm. BaO, SO3 22-0 22-0 

Heat for 1 equiv. BaO, SO3 . . 320-7 

Nitrate of Barytes and Sulphate of Copper. 

o o 

Temperature of air 14-4' 14-4 

Increments observed 0-88 0-91 

Heat for 1 grm. BaO, SO3 23-0 24-5 

Heat for 1 equiv. BaO, SO3 . . 346-2 

The salts of lead were next examined. The precipitation of the sulphate 
of lead took place with the same facility as that of the sulphate of barytes, 
the thermometer attaining the maximum in eight minutes. 

Acetate of Lead and Sulphate of Magnesia. — The acetate of lead was pure 
and in crystals, 4-17 grms. precipitated by oxalate of ammonia gave 2*454 grms. 
oxide of lead, which exactly agrees with the theoretical composition of the 
salt. In each of the following experiments, 30-80 grms. acetate of lead were 
taken, corresponding to 24*63 sulphate of lead : — 

o o 

Temperature of air 12-7 12*3 

Increments observed 1*01 0*97 

Heat for 1 grm. PbO, SO3 9-9 9*9 

Heat for 1 equiv. PbO, SO3 . . 187*6 

Acetate of Lead and Sulphate of Soda. 

O Q 

Temperature of air 12*3 12*2 

Increments observed 0*84 0-86 

Heat for 1 grm. PbO, SO3 8-3 8-5 

Heat for 1 equiv. PbO, SO3 . . 159*2 

Acetate of Lead and Sulphate of Zinc. 

° o 

Temperature of air 12-3 13-9 

Increments observed 0-41 0-37 

Heat for 1 grm. PbO, SO3 4-1 3-7 

Heat for 1 equiv. PbO, SO3 . . 73-9 

In the last experiment the precipitation was so slow that the thermometer 
did not attain the highest point for thirteen minutes after the solutions were 
mixed. 

When the salts of lead are precipitated by a neutral oxalate, the heat dis- 
engaged is much greater than when they are precipitated by a sulphate. I 
have not examined in detail the increments of temperature in this class of 
precipitations, but in one experiment, in which the acetate of lead was pre- 
cipitated by the oxalate of potash, 36-2 units of heat were obtained for each 
gramme of oxalate of lead. 

In the experiments next to be described, a dilute acid was substituted for 
one of the neutral solutions. 



74 REPORT — 1849. 

Chloride of Barium and Sulphuric Acid. — The same quantities of chloride 
of barium and of water were taken as in the experiments with the neutral 
sulphates. A slight excess of sulphuric acid was employed to secure com- 
plete precipitation. 

Temperature of air 17'8 18-4. 15-1 9-8 

Increments observed 3-44. 3-46 3-38 3*42 

Heat for 1 grm. BaO, SO3 45-6 45*6 44-0 44-2 

Heat for 1 equiv. BaO, SO3 . . . . 654-6 

Nitrate of Barytes and Sulphuric Acid. — As in the former experiments 
half the usual equivalents only were taken. 

o o 

Temperature of air 15*0 15'3 

Increments observed 1'50 1*49 

Heat for 1 grm. BaO, SO3 40*4 39-2 

Heat for 1 equiv. BaO, SO3 . . 580-2 

Acetate of Barytes and Sulphuric Acid. — Half equivalents were taken in 
this case also. ^ „ 

Temperature of air 12*3 12*5 

Increments observed 1-90 1-91 

Heat for 1 grm. BaO, SO3 49-5 49-3 

Heat for 1 equiv. BaO, SO3 . . 720*2 

Acetate of Barytes and Oxalic Acid. — 1 1 -2 grms. of acetate of barytes and 
5'33 grms. oxalic acid taken. 

o o 

Temperature of air 12'3 12-8 

Increments observed 1-19 1*19 

Heat for 1 grm. BaO, C^ O3 . . 22-1 21-8 

Heat for 1 equiv. BaO, Cg O3. . 309-0 

Acetate of Lead and Sulphuric Acid. — Of the acetate 30-8 grms. taken and 
an equivalent of the acid. 

Temperature of air 14*9 14-1 

Increments observed 2*84 2-86 

Heat for 1 grm. PbO, SO3 . . . . 28-0 29*2 

Heat for 1 equiv. PbO, SO3 . . 542-0 

Nitrate of Lead and Sulphuric Acid. — Of nitrate of lead 26-26 grmaj 
taken. o o 

Temperature of air 9*8 10-3 

Increments observed 1*63 1*66 

Heat for 1 grm. PbO, SO3 16-3 16-4 

Heat for 1 equiv. PbO, SO3 . . 309-8 

Acetate of Lead and Oxalic Acid. — 15-4 grms. of acetate of lead wer 
taken. o 

Temperature of air 9-8 

Increment observed 2-12 

Heat for 1 grm. PbO, C^ O3 4-3 

Heat for 1 equiv. PbO, C^ O3 792-9 

These experiments can only be regarded as introductory to an extended 
and interesting subject of inquiry. With such limited data, it would be pre- 
mature to attempt to draw any general inferences. 

Solution of Metals in Nitric Acid. — Every chemist is familiar with the 



ON THE HEAT OF COMBINATION. 7S 

violent action of nitric acid on zinc and copper, and the abundant evolution 
of gas which accompanies it. But the facility with which the gases may be 
condensed by the acid solution is probably not so generally known, and 
when the experiment is made for the first time cannot fail to excite surprise. 
If a small vessel of thin German glass, of about the capacity of half a fluid 
ounce, be half-filled with nitric acid of density T^, and a slip of zinc be sus- 
pended in the upper part so as not to touch the acid, the flask hermetically 
sealed, and finally inverted while surrounded with cold water, a very violent 
action will occur, but without bursting the vessel. Having ascertained these 
facts, there was little difficulty in measuring the heat disengaged during the 
solution of the metals in nitric acid. The metal was weighed in a glass tube 
open at one end, which was introduced into a thin glass vessel containing 
nitric acid of specific gravity 1"4<. The latter was then carefully closed and 
introduced into a copper vessel filled with water, and suspended in a metallic 
cylinder which was capable of rotation. On inverting the apparatus, the 
metal and acid came into contact, and the solution was completed in a few 
seconds. The rotation was afterwards continued for five minutes, which was 
sufficient to diffuse the heat disengaged through every part of the calorimeter. 

Solution of Zinc in Nitric Acid. 

I. II. HI. IV. 

. o o o o 

Temperature of air 4*5 6*2 8'0 5*8 

Increment found . . 2-66 2*78 2-83 2*71 

Increment corrected 2*65 2*77 2*82 2-71 

Weight of zinc ... . 0-587 grm. 0*600 grra. 0-615 grm. 0-604 grm. 

Weight of water . . 294-8 284-4 289-3 294-6 

Value of acid 7*4 6-9 6-5 6-6 

Value of vessels 14-3 14-3 14-3 14*3 

Heat of combination 1429 1411 1422 1420 

Hence we have for the heat disengaged during the solution in nitric acid 
of— 

1 grm. zinc 1420 

1 equiv. zinc 5857 

Solution of Copper in Nitric Acid. 

I. II. III. IV. 

Temperature of air . . 8-9 6-8 7-8 8-5 

Increment found 2*56 2-58 2-58 2-57 

Increment corrected . . 2-55 2-56 2-57 2-56 
Weight of copper .... 1-202 grm. 1-204 grm. 1-206 grm. 1-21 3 grm. 

Weight of water 274-2 273-2 273-3 275-4 

Value of acid 14-5 16-8 15-6 15-5 

Value of vessels 16-8 16-8 16*8 16-8 

Heat of combination . . 648 652 651 650 

We have therefore for the heat disengaged during the solution in nitric 
acid of — 

1 grm. copper 650 

1 equiv. copper 2578 

I made several attempts to determine the amount of heat disengaged in 
the solution of iron in nitric acid, but although acids of different strengths 
were employed, I was unable to obtain satisfactory results, as the iron always 
assumed the passive state before a sufficient quantity was dissolved to raise 
the temperature of the water in tlie calorimeter through 1°. Silver, bismuth 



76 llEPORT — 1849. 

and other metals were also tried, but the solution did not proceed with suffi- 
cient energy. 

The numbers 5857 and 2578 obtained above, are very nearly in the same 
ratio as 5366 and 2394, which, according to ray experiments (and their results 
differ little from those of Dulong), express the quantities of heat set free by 
the combustion of zinc and copper in oxygen gas. This shows clearly that 
the oxidation of the metals is the principal cause of the heat produced during 
their solution in nitric acid. Other causes of thermal change however exist, 
which must exercise a considerable influence. Such are the combinations 
of the oxide with the nitric acid, the separation of the elements of a portion 
of the nitric acid during the solution, and the condensation of the oxygen gas 
during the combustion. From these and other circumstances, it is not un- 
likely that the numbers expressing the quantities of heat disengaged in these 
reactions will not be found in all other cases to be so nearly in the same 
ratio as in the foregoing examples ; but it may be presumed that the general 
results will be the same, and that those metals which produce a greater 
amount of heat by their combustion in oxygen will also produce a greater 
amount of heat when dissolving in nitric acid. 

The heat produced by the solution of copper in nitromuriatic acid is, 
according to the result of a single trial, about yth less than that produced by 
its solution in nitric acid. 

Metallic substitutions. — I have lately treated this part of the subject at so 
great length in a paper published in the Philosophical Transactions, that I 
shall here only transcribe the general result of the investigation. It is thus 
expressed : — " When an equivalent of one and the same metal replaces an- 
other in a solution of any of its salts of the same order, the heat developed 
is always the same ; but a change in either of the metals produces a different 
development of heat." This is evidently an analogous law to that already 
stated for the thermal changes which accompany basic substitutions. The 
numerical results are however entirely different in their details. 

Combustions in Oxygen Gas. — Since the time when Lavoisier published 
his celebrated experiments on the heat produced by combustion, the subject 
has frequently engaged" the attention of chemists. But few results were ob- 
tained of any scientific value, till the posthumous publication of Dulong's 
valuable researches, which have formed the basis of all subsequent inquiries. 
More recently, Grassi and Fabre and Silbermann have examined the same sub- 
ject, and I have myself lately published a set of experiments upon it, which 
were made some years ago. With the exception of some of Grassi's results, 
the numbers obtained by the different experimenters agree very nearly with 
each other, and we may therefore consider the quantities of heat developed 
by the combination of oxygen with the more important simple bodies and 
with some of their compounds to be determined with considerable precision. 
Fabre and Silbermann have also examined the combustion of carbon in the 
protoxide of nitrogen. A tabular view of nearly all the numerical results 
hitherto obtained, will be found in the edition of Gmelin's Hand-book of Che- 
mistry recently published by the Cavendish Society. I shall here therefore 
confine myself to a few general observations. 

The following bodies in their ordinary physical states, viz. hydrogen, car- 
bonic oxide, cyanogen, iron, tin and antimony, disengage nearly the same 
amount of heat in combining with an equal volume of oxygen. The num- 
bers which express the heat of combination in these cases do not in fact differ 
from one another more than ^'^th part of the whole quantity, — a difference 
which is nearly within the limit of the errors of experiment. This observa- 
tion applies only to the quantities of heat actually obtained by experiment. 



ON THE HEAT OF COMBINATION. 77 

But if we apply corrections for the heat due to the changes of physical state 
which occur in some of these reactions, the same agreement will no longer 
be observed. Thus in the combustion of carbonic oxide, the resulting com- 
pound is obtained in the gaseous state, while in the combustion of hydrogen 
it is condensed during the course of the experiment into a liquid ; and if, 
from the entire quantity of heat evolved in the latter case, we deduct that 
arising from the condensation of the vapour of water, the result will no 
longer agree with the quantity of heat obtained in the former case. Protoxide 
of tin may probably be added to the foregoing list, and perhaps also phosphorus, 
which disengages however a little more heat than the other bodies. 

Sulphur, copper and the protoxide of copper, disengage, during their com- 
bustion in oxygen gas, a little more than half the quantity of heat evolved 
by the preceding class of bodies. Carbon occupies an intermediate position, 
while zinc gives out a larger quantity of heat than any of the bodies already 
enumerated ; and potassium a still larger quantity than zinc. The combus- 
tion of a large number of carbo-hydrogens, alcohols, aethers and organic acids 
has been examined by Fabre and Silbermann. Their results prove the opi- 
nion to be erroneous, that if we subtract the oxygen in the form of water, 
the remaining elements give the same amount of heat as in the free state. 

In the reduction of oxide of iron by hydrogen gas, no perceptible evolu- 
tion of heat occurs, while in the reduction of the oxide of copper by the 
same gas, it is well known that ignition takes place, unless the experiment is 
conducted very slowly. These phaenomena are at once explained by the fact, 
that in combining with oxygen, hydrogen gas disengages nearly the same 
quantity of heat as iron, and twice as much heat as copper. 

Fabre and Silbermann have observed that the heat of combustion is influ- 
enced to a considerable extent by the physical state in which the combustible 
exists before combination. According to their experiments, carbon in the 
form of the diamond disengages 7824? units of heat during its combustion in 
oxygen gas ; in the form of graphite 7778 units ; and in that of wood-char- 
coal 8080 units. According to my own experiments and those of Despretz, 
the combustion of wood-charcoal produces only about 7900 units. Fabre 
and Silbermann have also supposed that they were able to detect differences 
in the quantities of heat disengaged by sulphur in its different allotropic 
states. The same chemists have also made the remarkable observation, that 
a much larger quantity of heat is evolved by the combustion of carbon in the 
protoxide of nitrogen than in oxygen gas. From this it should follow that 
in the separation of the elements of the protoxide of nitrogen, heat would be 
set free. Accordingly, by passing the protoxide of nitrogen through a pla- 
tina tube heated to redness by burning charcoal in a suitable apparatus, it 
was found that a larger quantity of heat was actually evolved than could be 
accounted for by the weight of charcoal burned. 

Combustions in Chlorine Gas, — Some years ago, I published the results of 
an investigation on the quantities of heat evolved in the combination of zinc 
and iron with chlorine, bromine and iodine ; and I have lately given an ac- 
count of a set of experiments on the combustion of potassium, tin, antimony, 
mercury, phosphorus and copper in chlorine gas. So far as I am aware, the 
only other experiments on this subject are those described by M. Abria on 
the combustion of hydrogen and phosphorus in chlorine. From a com- 
parison of the results, it appears that in several cases the quantities of heat 
evolved during the combustion of the same metal in oxygen and chlorine are 
nearly the same. This observation applies particularly to the cases of iron, 
"tin and antimony. Zinc however disengages a greater quantity of heat with 
chlorine (6309 units) than with oxygen (5366 units), and copper nearly twice 



78 iiEPOBT-^i849. 

as much (3805 and 2394? units). Phosphorus, on the contrary, gives less 
heat with chlorine than with oxygen (2683 and 4509 units). On comparing 
the quantities of heat disengaged by different bodies in combining with the 
same volume of chlorine, it will be found that potassium disengages a larger 
amount of heat than any other body hitherto examined, twice as much as 
zinc, and nearly four times as much as tin, antimony or copper. 

Combinations of Bromine and Iodine. — The heat disengaged by the same 
body in combining with bromine is less than with chlorine, and with iodine 
less than with bromine. The greater development of heat in the case of 
chlorine is at least partly due to that element being in the gaseous state be- 
fore combination. In some early experiments, I observed that the quantities 
of heat developed on converting equivalent solutions of the sesquichloride, 
sesquibromide and sesquiiodide of iron into the corresponding proto-com- 
pounds were equal. When a solution of protochloride of iron is converted 
into sesquichloride by agitation with chlorine gas, a definite disengagement 
of heat occurs, as also in the formation of the sesquibromide of iron by the 
combination of the protobromide and bromine ; but in the corresponding re- 
action between the protoiodide of iron and iodine, no change of temperature 
can be observed. 



Report of the Committee on the Registration of the Periodic Phenomena 
of Plants and Animals, consisting o/ Edwin Lankester, M.D.,Mr. 
R. Taylor, Mr. W. Thompson, Rev. L. Jenyns, Prof. Henslow, 
Mr. A. Henfrey, Sir W. C. Trevelyan, Bart., and Mr. Peach. 

Since the last Meeting of the Association, your Committee have made 
several alterations in the Tables for the purpose of registering the periodic 
phaenomena occurring in plants and animals, which were then submitted for 
the approval of the members. These tables have been sent to upwards of fifty 
members of the Association and others, who have undertaken to observe. 

But few of these tables have yet been returned to the Committee, but they 
hope at the next meeting to find more abundant fruit of their labours. They 
have to acknowledge, however, the receipt of a very complete registration of 
the periodic phaenomena of the plants and animals in the neighbourhood of 
Swansea, by Matthew Moggridge, Esq. ; also observations on periodic phae- 
nomena for 1848, at Polpero in Cornwall, by J. E. Couch, Esq. ; a list of 
the visitation and departure of birds at Llanrwst in Wales, by J. Blackwall, 
Esq. ; and observations on the foliation and defoliation of plants, by T. L. 
Lloyd, Esq. 



Ninth Report of a Committee, consisting of H. E. Strickland, 
Prof. Daubeny, Prof. Henslow, and Prof. Lindley, appointed 
to continue their Experiments on the Growth and Vitality of Seeds. 

During the past summer, a portion of each kind of seed collected in 1841 
and 1846 were resown at Oxford and Chiswick, together with a few other 
kinds contributed by Miss Molesvvorth, of Cobham Lodge, Surrey. 

Those forwarded to Cambridge arrived just after Mr. Murray (Curator of 
the Botanic Garden there) had started for a botanical tour in the north, and 
he did not receive them till his return, when it was too late this year to have 
them sown. A statement respecting them will therefore be given in the Re- 
port for 1850. 



ON THE VITALITY OF SEEDS. 



79 



We again beg to remind persons interested in these experiments, that we 
shall be glad to receive contributions of seeds of known date, whether old or 
new, especially those of genera not named in the List submitted to the Meeting 
of the Association in 1848. 

The results obtained will be seen by reference to the following Table : — 



Name and Date when gathered. 



1841. 

1. Vicia sativa 

2. Daucus Carota 

3. Cannabis sativa 

4. Pastinaca sativa 

5. BrassicaRapa 

6. Linum usitatissimum 

7. Lepidium sativum 

8. Polygonum Fagopynim... 

9. Phalaris canariensis 

10. Brassica Napus 

11. Carum Carui 

12. Petroselinum sativum ... 

13. Trifolium, sp 

14. Lactuca sativa 

15. Brassica oleracea 

16. Pisum sativum , 

17. Faba vulgaris 

18. Phaseolus multiflorus .., 

19. Triticum sestivum 

20. Hordeum vulgare 

21. Avena sativa , 

22. iEthusa Cynapioides 

23. Antirrhinum majus , 

24. Calendula pluvialis 

25. CoUinsia heterophylla ... 

26. Datura Stramonium 

27. Gilia achillaefolia 

. Lasthenia californica 

29. Ligusticum Levisticum . . 

30. Pseonia, mixed vars 

31. Verbascum Thapsus 

1842. 

32. MelUotus macrorhiza 

1846. 

33. Anemone coronaria 

34. Amopogon Dalechampii 

35. Betonica hirsuta 

36. Bunias orientalis 

37. Foeniculum dulce 

38. Psoralea bituminosa 

39. Ranunculus caucasicus . . 

40. Rhagadiolus stellatus 

41. Thalictrum minus 

42. Veronica peregrina 

1847. 

43. Chenopodium Quinoa .. 

44. Panicum Meliaceum 

1848. 

45. Thalictrum minus 



No, 
sown. 



50 

100 

50 

100 

300 

150 

100 

50 

100 

150 

200 

50 

150 

50 

50 

50 

25 

25 

100 

100 

100 

100 

300 

200 

300 

100 

200 

200 

100 

100 

500 

250 

100 

50 
100 

50 
100 

50 
100 

50 
100 
100 

200 
200 

200 



No. of Seeds of each 
Species which vege- 
tated at 



Ox- 
ford. 



Cam- Chis- 
bridge. wick, 



128 



29 



10 



Time of vegetating 
in days at 



52 



28 



12 



15 



40 



16 



20 



Cam- 
bridge. 



Remarks. 



Chis- 
wick. 



26 



14 



14 



80 REPORT — 1849. 

Report concerning the Observatory of the British Association at Kew, 
from Aug. 9, 1848 to Sept. 12, 1849. By Francis Ronalds, 
F.R.S., Honorary Superintendent. 

Notwithstanding the resolution which was adopted at the last meeting of 
the British Association for discontinuing observations at Kew (a resolution 
partly founded upon an opinion that the establishment could not be carried 
on in a manner satisfactory to the Association " on so low a scale of expendi- 
ture" as that which had hitlierto been found practicable), it was deemed 
expedient to furnish a fund for defraying the cost of prosecuting experiments 
then in progress, together with a few necessary expenses of the establishment ; 
and another sum lor the reduction and discussion of the series of electric ob- 
servations which commenced in August IS'tS and terminated in August 1848. 

The last year's work has therefore been principally devoted to reduction 
and discussion by Mr. Birt of the electric observations recorded in the five 
annual volumes preceding this year's volume, and to the due prosecution of 
the magnetic experiments which were contemplated. 

I much regret that it has not been in my power to do more, as regards 
the discussion of the observations, than confer with Mr. Birt upon the course 
which was to be adopted *. The other objects became latterly so pressing, 
and in my humble opinion so important, that it has been quite out of my 
power to devote the time and attention to the subject which it eminently 
deserves. The observations have furnished means of computing results, which, 
combined with the successful prosecution of experiments on a general pho- 
tographic system of registration, will, I trust, be deemed ample justification 
of the opinions expressed by the last Kew Committee, presided over by Sir 
John Herschel, and participated in by the Council, as to the utility of the 
Kew establishmentf . 

Mr. Birt's reductions, &c. will appear in a separate Report ; and I now 
proceed to devote a i'ew lines (as usual), first to the state of affairs at Kew, 
so far as regards the Building, Instruments, &c., and secondly, to an account 
of the experiments and operations which have been conducted here during the 
last (Association) year ; and a few other matters connected with experimental 
inquiry. 

I. The Building, &c. 

The premises having been repaired (outwardly) at the expense of Her 
Majesty's Government in the previous year, nothing additional has been 
required to be done in that respect ; but I am sorry to add that some parts 
of the interior are sadly afflicted with dry-rot. 

The Quadrant Room has, in consequence of the extraordinary solidity of 
the foundation, contributed largely to the success of experiments on, and to 
testing the efficiency of, the self-registering magnetic apparatus, which has 
been sent by the Superintendent of Magnetic Colonial Observatories, our 
excellent General Secretary, to Toronto. For the immediate support of that 
apparatus, two solid stone slabs were attached at the base of the wall tem- 
porarily. 

The principal Electric Conductor has maintained its original vertical 
position (with the exception of a slight bending towards the north-east, 
owing to the prevalence of south-west winds) amid the attacks of six years' 
tempests; and the insulating power of its only support is improved, rather 
than otherwise, since its erection by constant heat and age. A little is 

• It was agreed that the Greenwich methods of reducing meteorological observations should 
(so far as was consistent with the different circumstances) be adopted, with modifications. 
t Vide Report of 18th Meeting, p. xvil. 



ON THE KEW OBSERVATORY. 81 

required to be done to prevent the entrance of rain (when violent gii:<ts 
occur) at the cap. 

The Voltaic Electrometers are a little deteriorated (in appearance princi- 
pally). 

Jlie Henley 'Electrometer (apud Volta) is certainly in a rather less efficient 
state than when new. Friction of pivots is ever bad in electrometers, and 
want of employment increases the evil tendency. 

The Wind Va7ie has been nearly destroyed by a ftdl, in consequence 
of some bad soldering at its supporting ring. 

The following instruments are all in an efficient state for use in obser- 
vation : — 



Thermometer' (standard). 
Wet-bulb Hygrometer. 
Daniels Hygrometer. 
Saussure's Hygrometer. 
Balance Atiemometer. 
Haiti and Vapour- Gauge. 



The Galvanometer. 

Discharger. 

Gold-leaf Electroscope. 

Distinguisher. 

Three Night registering Electrometers. 

Barometers (ttvo). 

The numerous instruments which have been employed in electric, magnetic, 
and other experiments and extraordinary observations are not materially, if 
at all deteriorated. Tiiey will be carefully enumerated in a general catalogue 
of the actual contents of the Kew Observatory arranged under six heads, 
viz. — 

1. Fixtures, furniture, &c. found in the building on the 1st of August 
1843. 

2. Apparatus supplied by means of a subscription in J 843. 

3. Apparatus, and materials for apparatus, purchased out of sums 
granted annually by the British Association, including a 50/. grant from 
the British Association for experiments. 

4. Apparatus presented to the British Association. 

5. Books the property of the British Association. 

6. Articles which are on loan to the British Association. 

II. Experiments, &c. 

Soon after the meeting of the British Association at Swansea in August 
1848, being very anxious to proceed with the magneto-registering system, I 
began to make drawings of apparatus on the plan of suspending the declina- 
tion magnet at right angles (horizontally) with the index arm (all else re- 
maining as before), in order to procure a greater extent of scale with the 
same amount of light ; but I'eflecting upon some valuable conversation which 
I had the honour to hold with Dr. Lloyd at the Swansea meeting, and on some 
suggestions of his afterwards, I made diagrams and calculations for trying his 
methods of attaching the lens to the magnet, and deflecting it by separate 
magnets, or by reversion of it, in order to procure a larger range of the in- 
strument itself. I submitted these ideas, &c. to Colonel Sabine, and received 
obliging and very useful hints from him. I also consulted profitably Mr. Ross 
the optician. 

At the beginning of November I had made arrangements, drawings, &c. 
for mounting a magnet on Dr. Lloyd's plan, which it was intended should be 
tried at Woolwich ; but the apartment (or observatory) selected not having 
ultimately been deemed very well-fitted for the purpose, I thought that the 
■ Kew building and the Kew establishment could and ought to be appropriated 
to the attainment of so desirable an end, that it was one exactly calculated 
for the proper business of the establishment, and Colonel Sabine agreed in 
these views I believe. 

1849. G 



82 REPORT — 1849. 

My continued instructive correspondence with Dr. Lloyd on the subject 
was very profitable, and new arrangements were in consequence contem- 
plated which were applicable to either plan (viz. that of using a detached 
lens as heretofore, or an attached lens with deflectors, &c.), for comparing 
them at Kew ; and Mr. Ross received some final instructions as to the work 
to be executed. 

But in the course of Mr. Ross's operations in December, a considerable 
improvement occurred to me in the management of the light, viz. that of 
suppressing the condensing lenses at the object-end of the camera, bringing 
the index much nearer to the lamp, and employing the focus lenses to pro- 
cure not only a distinct image of the index, but also a brilliant pencil of 
light (broad enough for oiir^ purposes) immediately from the flame itself. 
By these means the time required to produce the desired effect upon the 
paper was very considerably reduced. Mr. Malone assisted me in these ex- 
periments zealously. 

Several improvements were also made in the construction and disposition 
of the time-piece {vide Plate II. K), &c. ; and at about this time, after 
many vain attempts, an improvement in the brilliancy of the flame itself was \ 
effected by a modification of Count Rumford's "Polyflame Lamp," of three flat] 
wicks, &c., and an especial adaptation of a high square copper chimney, &c. [ 
{vide Plates 11. and III. D). 

The reason for not instituting the above-mentioned comparison of lenses, I 
was chiefly that of finding the expense of a lens properly adapted to the j 
purpose very considerable. Yet I trust that my anxiety to carry out prac- ! 
tically Dr. Lloyd's important suggestions, combined with the occurrence of] 
more favourable circumstances, may not be ultimately unavailing, or that] 
some less costly method than we thought of may be propounded. 

In February IS^Q Colonel Sabine wished to know the difference of effect 
(under such circumstances as those in which the Toronto horizontal force 
magnetometer finds itself in magnetic storms, &c.) between a slit in a shield 
and an index. The slit had also occurred to Dr. Lloyd and others, and I 
resolved upon attempting a strictly practical solution of the question. 

But before the experiment had been tried upon paper, it struck me 
that the Daguerreotype process would be far preferable to Talbotype in 
these cases of rapid and great variations, if not in every case, in consequence 
of the greater sensitiveness, greater capability of retaining the integrity of its 
normal condition, and greater delicacy (or sharpness) of outline ; and the 
result of the first trials fully confirmed the Colonel's sagacious anticipations 
of the superiority of the slit, at the same time that the use of silver sur- 
faces became at once indispensable for future operations. On the 23rd of 
February, two specimens, extremely well defined, were procured, one in 
twenty seconds, the other in thirty. The first was the stronger (too strong). 

The next problem was to copy these impressions, for it was deemed too 
expensive and cumbersome to preserve them ; and I spent much time in 
trials on Mr. Edwards' plan, viz. that of pressing off a part of the mercury 
upon black paper coated by a solution of isinglass. The sticking, and con- 
sequent tearing of the long piece of paper presented great obstacles (amongst 
others) to the success of these attempts; and I began, with Mr. Malone's 
obliging assistance, to try whether the Talbotype process could be applied 
profitably to copy these metalline impressions. A specimen is preserved; 
but we arrived at the conclusioa that the trouble and cost of time^ &c. in the 
execution would be too great, and that no copy on paper could ever be so 
sharp and beautiful as the metalline impression itself. 

In the beginning of April I made a little experimental addition to the 



ON THE KEW OBSERVATORY. 83 

clock-work, for imitating long excursions of a magnet in short intervals, in 
order to prove the efficacy of the above-mentioned new arrangements relative 
to light, the slit and the Daguerreotj^pe process in such cases, and adapted 
it to some horizontal-force apparatus which was intended for the Toronto 
Observatory ; for it was by far too tedious a task to wait for any disturbance 
approximating in extent to those which occur in Canada. A specimen is 
preserved of the result, which makes out the case (of success) very well. 
But we already begin to contemn these dirty, although efficient, specimens. 

I also began to think about etching the impressions on the plate itself, and 
received some valuable information on the subject from Mr. Malone, Mr. 
Hodgson of Winchfield, and other gentlemen ; and I found that the usual 
cost of plates was somewhat too high. 

Toward the end of May, Daguerreotype apparatus for cleaning, polishing, 
coating, &c. silvered plates of the length required for our purposes claimed 
attention, with special regard to saving of time and labour. 

About the same time Dr. Lloyd visited the observatory, and suggested the 
advantage of procuring a zero line upon the plate formed by the action of 
the same source of light which produced the magnetic curve (as I had from 
the first procured on paper), instead of depending upon the edge of the 
plate for reading off ordinates. This hint appeared so judicious, that 
(although presenting difficulties in contrivance and execution, and thus 
creating delay in the preparations for shipment of the Toronto bifilar appa- 
ratus) I thought it right to try experiments, and attained the object. The 
method will be easily understood presently. 

I had now also hit upon an obvious, but very useful addition to all appa- 
ratus calculated to measure ordinates of magnetic and other curves from a 
given abscissa, within certain but extensive distances. This instrument 1 call 
the Scale Board (vide Plate IV. figs. 2 and 3), and will describe it below. 

The last-executed improvements have been upon the instruments used in 
<;leaning and coating the plates, in which Mr. Nicklin has materially assisted ; 
and in carefully etching, or rather engraving and etching, the plate 
without using (at first) a " ground," for which I am chiefly indebted to Mr. 
Wood. The plate which has been thus treated is still capable of receiving 
more impressions in the camera, although the first impression is deeply en- 
graved, and capable of printing any (usual) number of copies. A printed 
specimen is preserved (vide Plate IV. fig. 4). 

About the first week in June I experienced great satisfaction in receiving 
a visit from Colonel Sabine, to inspect the apparatus (which had been ex- 
perimented upon, improved and tested at our Kew Observatory, under the 
auspices of the British Association) for a horizontal-force magnetograph, to 
go to the Toronto Observatory. It (excepting the stone pillars) was shipped 
for Montreal, and addressed to Captain Lefroy, Director of the Magnetic 
Observatory, Toronto, in about the middle of last August, and may be thus 
described. 

(Similar letters refer to similar parts in all the figures, excepting in figs. 2 
and 3, Plate IV.) 

The figures of Plates I. II. III. and fig. 1 of Plate IV. are drawn to one- 
eighth of size. Fig. 2 and 3 of Plate IV., and all those of Plate V., are one- 
fourth of size. Fig. 4 of Plate IV. is of real size. 

V (Plate V. figs. 1 and 2, &c.) is the magnet-box, coated (as usual) inside 
and out with gold paper, and provided with a short tube (i;'), which descends 
and opens into A. 

A is the camera box. a' is a solid brass casting, forming in part one of 
its ends. 

g2 



84 REPORT — 1849. 

B is a fifteen4nch magnet, belonging to a bifilar magnetometer of Dr. 
Lloyd's construction. 6- is its stirrup. 6' a pair of light brass tubes, con- 
nected with b- by entering a short tube attached to b-, and permitting a 
horizontal adjustment (of b'^). The counterbalancing ball at one end is also 
adjustible (for poising b^ properly). 

6' (figs. 1, 3, 4, 5) is the moveable shield, composed of very light sheet 
brass, curved and attached to a little tube, which is clamped by a peculiar nut 
and screw to the end of b^. It has a very narrow slit at its lower edge in 
the centre. 

b* is the usual copper damper, tJie upper and lower central portions being 
formed into curves for the free "play" of b- and b^. b^ b^ are its supports. 

O is a diaphragm plate, whose aperture is about an inch long liorizontally 
and a quarter of an inch wide. It carries 

o', which is the fixed shield, similar in form to b\ and attached to O by 
means of a little bolt, washers and nut (o^). It is capable of adjustments for 
horizontality, height, &c. At about three-eighths of an inch from its centre 
is a slit, somewhat larger than the slit in ¥. This shield stands at a distance 
of about a tenth of an incii from 6', and at about one-fortieth of an inch 
higher than 6'. 

C is a glass plate admitting light into the camera. It has in front a small 
brass sliding-shutter. 

D (Plates I. and III.) is a lamp constructed on Count Rumford's poly- 
flarae principle of three flat wicks raised and lowered by rack- work. 

rf' is its high squared copper chimney, provided with a glass plate about 
three-quarters of an inch high placed opposite to the best part of the flame 
(or flames). 

E is the mouth, consisting of two angular pieces (as seen in Plate V. 
figs. 1 and 2), and of two little plates attached to them, forming the lips and 
aperture e', which aperture can be diminished or increased at pleasure after 
relaxing the little nuts of screws which pass through oblong slits cut 
through a'. 

A horizontal aperture, of about a quarter of an inch broad, cut through 
a', admits the light which forms the focus at e' of the 7noveable slit (in 6'), 
and a little vertical aperture in a' admits the focus of the fixed slit in o'. 
The magnetic curve and zero line are produced by these foci respectively. 

F is the slider case, for receiving the sliding frame. 

/* is a perfectly true ruler of brass, attached vertically to a' by means of 
three screws passing thfough it, through three thick washers (or little pillars), 
and through three oblong slits in a', &c. It is capable of adjustments for 
perpendicularity, &c. 

f'^ is a roller spring, attached to a', and acts upon the slider frame side- 
Avise, pressing it gently against the ruler. 

f^ is a pair of similar springs, acting upon the frame in front, and pressing 
the glass in the frame against the mouth. 

G is the lens tube, containing two groups of Ross's achromatic lenses. 

g^ is apparatus (of sliding plates, &c.) for the support and due centring 
of G, &c. 

g'^ is apparatus of studs, pinion, milled head, key, &c. for moving the rod 
gr3, which is attached to the stud at </*, and serves for the adjustments to 
focus (of G). 

H is the sliding frame suspended in F. A' are the spring bars for re- 
taining the plates, either metallic or glass, in their proper places, h^ are 
friction rollers, h^ is a hook with a screw in it, which clamps the gut line, 
entering a hole in the top of H. 



ON THE KEW OBSERVATORY. 85 

I (Plates I. to IV.) is the pulley ou the hour-arbour of the time-piece. 
i' the gut line suspending H. i^ is the counterpoise to H. 

K is the time-piece, with its weights, pendulum, &c., and a lever with fork, 
k^, for stopping and starting the clock at any given second. 

A' is the support of K and F. 

k- are brass tubular braces. 

P'* and P^ are stone pillars, whose common centres are in the mean mag- 
netic meridian (about). 

P^ and P^ are stone pillars, whose common centres are at right angles to 
the magnetic meridian (quasi). 

Q are stone brackets tixed in P^ and P^ for the support of V. 

R is a cross slab of stone, resting on P'^ and P^^. 

»•• is the cross piece of mahogany (used in Dr. Lloyd's arrangement), 
secured firmly, with means of adjustments, upon R by bolts and nuts, r'^. 

S is the torsion apparatus (of plate, &c.) (Dri^ Lloyd's). 

s^ the suspending wire, passing round the grooved wheel. 

s'', on the axis of which b^ rests " by inverted Y®." 

T the glass tube resting on t\ which is a fillet contained in f^, which is a 
neck or brass tube attached to V. 

X is a black marble slab, carrying A, A', &c., and supported upon P^ 
and P^ very firmly, but admitting of a small adjustment (on occasion) about 
the common axis of the suspending wires, s^. 

Y (Plate IV. fig. 2) is the silvered plate (in the scale board). 

y' is the magnetic curve produced by the focus of the slit in the moveable 
shield (6'). 

t/^ is the zero line produced by the focus of the slit in the fixed shield (»•). 

It will be easily perceived that in the arrangement which has now been 
described no hygrometric expansions and contractions can have sensible effiect 
upon the required result, and / believe that thermometric variations are 
equally unappreciable. 

The scale board (Plate IV. figs. 2 and 3), for measuring off rapidly and 
correctly ordinates formed by the magnetic or other curve with the zero 
line, is thus constructed : — 

A is a mahogany board. 

a', &c. are four screws attaching it to 

B, which is another heavier board, and which it is well to clamp upon a 
sloping desk. 

C is a ruler attached to B by a screw at each end, passing easily through 
an oblong aperture, and allowing a lateral free motion of the ruler upon B. 
A blank ivory scale is fixed upon C. 

ci is a milled-headed screw, acting by its shoulder upon a piece which 
presses C inwards, or against the right-hand edge of Y. 

c- and c3 are screws passing through another ruler, 

M, &c., fixed immoveably upon B, and acting by their ends upon two little 
brass sliders which press upon the left-hand edge of Y. This fixed ruler 
(M) carries a scale of white metal, upon which divisions, representing hours, 
half-hours, quarters and five minutes, are engraved, a length of one inch 
representing one hour (for the slider H in the case F is moved by the clock 
at a rate corresponding with these values). Two spiral springs are con- 
tained in B, which cause the two sliders pressing on Y to resume their nor- 
mal positions when c^ and c^ are not employed. 

T is the ebony stock of the T square. 

V is its blade of white metal, upon which is engraved on one of the fiducial 
edges divisions representing fiftieths of an inch, and on the other sixtieths. 



86 REPORT — 1849. 

counting from the zero mark, 0, on each series ; and it is affixed to T by a 
milled screw passing through one of the oblong slits at either end, so that 
either scale may be used, or a blade much more minutely divided might be 
substituted. 

A good double lens, ov pair of lenses, may be used upon a stand with this 
apparatus for reading the scales. 

The manner of using this instrument is perhaps sufficiently obvious. The 
zero of the o/-rfz>2a<e 5C«/e (<■) is adjusted (if necessary) to that right-hand 
edge and extremity of the zero line (y*) which is furthest from the time 
scale, M, transversely (after relaxing the screw near T). The ordinate 
scale is, secondly, applied to the other extremity of y- ; and if the zero point 
on it should not coincide with y"^, then the screw c' is relaxed, and the ap- 
propriate left-hand screw (either c" or c') is slowly screwed up until exact 
coincidence occurs. Then f' is screwed up again. 

Particular information, &c. as to the use of the apparatus sent to Toronto 
was carefully detailed, and some hints relative to the (seemingly) best modes 
of operating upon the long Daguerreotype plates, &c. were set down for the 
use of Captain Lefroy, &c. 

These details are not requisite here. The former ^mfZ of information has 
been already published, i. e. when my earlier experiments on registration 
were made known* ; and the latter is comprised in great part (although not 
in sufficient abundance) in several well-known publications. 

Proceeding now with the relation of the other circumstances connected 
with experimental inquiry at Kew, I may add, tiiat at the visit above men- 
tioned of Colonel Sabine we held some conversation on the subject of con- 
structing a vertical-force magnetograph, which had previously occupied our 
attention, when the Colonel relieved me from a difficulty by hinting that an 
arm might be erected vertically upon the centre of the magnet, to carry the 
shield with its slit. By this means the injurious proximity of the lamp to 
the magnet at night will be entirely avoided. 

This apparatus is in an advanced state of preparation for Toronto. 

My correspondence with the Rev. Alfred Weld, respecting the establish- 
ment of a self-registering electric and magnetic observatory at Stonyhurst, 
after occupying much time (in making plans, drawings, &c.), has not been 
as yet followed by the erection of a suitable building at that locality. 

In August 184-8 I received from the Superintendent of the Great Western 
Hallway Electric Telegraph some further and rather curious notices of the 
deflections of the needles, &c. at Paddington, Slough and Derby. At Pad- 
dington, on the 9th of August, at about 1^ 50™ p.m., during a storm, an ex- 
plosion occurred in the office like that of a gun fired, and the cross wire was 
fused. The same thing occurred at Slough at the same time. 

The most remarkable effects upon these wires are those which are pro- 
duced hyjbgs; and I apprehend that experiments relative to them would be 
interesting, and perhaps profitable. 

Amongst several distingui;jhed visitors to the observatory in the past year, 
Don Manuel Rico, Director of the Madrid Observatory, came to converse 
on the subject of erecting an electrical apparatus like ours at that building, 
and gave me a rough plan and description of it. 

The site appears to be extremely favourable. Experiments and observa- 
tions in that latitude would form an important link in a geographical series 
comprising the observations (now probably going on by means of similar 
apparatus) at Bombay, and others to be instituted in a very high latitude (as 
Alten, e.g.). 

* Vide Phil. Trans., Part 1. for 1847. 



^1 



ON THE KEW OBSERVATORY. 8/ 

I trust that other gentlemen, visitors to Kew, have derived some little 
pleasure, and even profit, from the results of their inquiries here, and that 
my limited correspondence on electric and other subjects with several gentle- 
men of scientific eminence has not been wholly profitless to all parties. 

I have usually set down under this head a little list of proposals for new 
experiments, or the continuation of old ones ; but the number of such-like 
propositions has accumulated so much faster than the means and time re- 
quired for their execution, that the catalogue arrives at an almost despairing 
magnitude. However it shall follow here, because it will at least serve to 
show that plenty of work could be done at Kew if we had plentiful means. 

1. Experiments to determine various points as to the construction of the 
declination and horizontal-force magnetograph, and particularly Dr. Lloyd's 
propositions concerning attached lenses. 

2. Idem, as to the vertical-force (balance) magnetograph. 

3. Idem, as to the completion of a self- corrective system for the barome- 
trograph. 

4. Idem, as to the best mode of constructing the thermometrograph. 

5. Comparison of long and short magnets, and their effects on the regi- 
stration compared particularly. 

6. Experiments in pursuance of some which were commenced here in 
1845 on the important &\xh]eci oi " frequeiicy" of atmospheric electricity; a 
subject ivhich has been most unaccountably neglected since the observatiotis of 
Beccaria at Turin in about 1750, and one which seems to me to grow in 
importance with the growth of our chemical and magnetic information. 

7. Experiments in pursuance of some which were made at Kew on insu- 
lation, and particularly on the insulation of air charged with a known 
amount of humidity, and at different temperatures, &c., a matter recommended 
for examination by Coulomb. 

8. Experiments in pursuance of the same course, but having especial 
reference to the measures of atmospheric tensional electricity, as indicated 
by Henley's and other electrometers, used in attempting to estimate properly 
high tensions. 

9. Experiments on apparatus for observing shooting stars. 

10. Experiments on the best mode of pursuing observations on terrestrial 
temperature, as recommended by Professor Forbes. 

11. Experiments on kites at known and constant elevations, in pursuance 
of one made at Kew in the year 1847j with a view to their real utility in 
meteorology. 

12. Experiments on the comparative advantages of plate and cylindrical 
surfaces in reference to their use in self-registering instruments, the former 
on William Nicholson's construction ; and also experiments on a mode of 
reading off the ordinates on such cylinders. 



88 REPORT — 1849. 

Report on the Experimental Inquiry conducted at the request of the 

British Association, on Railway Bar Corrosion. 

By Robert Mallet, M.R.I.A., Mem. Inst. C.E. 

It having been long loosely rumoured that railway bars corrode less when 
in use, i. e. travelled over, than when out of use, and the only evidence for this 
being that they appear to do so to the eye, and several vague speculations 
having been broached by engineers and others to account for the assumed 
facts, it seemed desirable to ascertain the truth experimentally, and also to 
determine at the same time the constants of abrasion by the action of the 
wheels of railway carriages, this latter being in fact a necessary prior question 
to the research as to corrosion. 

A general sketch of the views promulgated on this subject is contained in 
my Third Report on Corrosion of Iron to the British Association in IS-tS ; a 
sum of £20 having been placed at my disposal by the British Association at 
the Rlanchester ISIeeting in 1842, for the purpose of these experiments. 

The first experiments were directed to the object of ascertaining the fact 
of any difterence in the amount of corrosion by air and water, &c. between 
railway bars in use and out of use, in an exact and unexceptionable manner; 
and from the great weight of the rails requiring a balance of great strength, 
this was found by no means an easy matter, as the difference of corrosion in 
any moderate time might be expected not very greatly to exceed the errors 
of weighing. The first sets of experiments arranged were on the Dublin 
and Kingstown Railway, upon that part of the line which lies near Sydney Pa- 
rade, at the Dublin side of the level crossing there. 

The line is quite straight, the brakes are never applied here, and the rails 
are level. Three sets of six lengths of fifteen feet rails each, were here laid 
down upon the coming into town or western line. 

The direction by compass of the rails at this point is north-west and south- 
east, and hence these rails were always traversed over in a direction from 
south-east to north-west. 

The experimental rails were laid in the following way : — Having been care- 
fully weighed, viz. two sets of bars of six each were laid into the coming-in line, 
and secured in the same way as all the others on the line, by cast-iron chairs 
and compressed wood wedges resting upon longitudinal memel sleepers, and 
with pine or memel filling-pieces between the chairs, filling up the spaces be- 
tween the bottoms of the rails and the tops of the sleepers. 

Of these two sets laid into the line, one set of six bars (No. 2 marked • •) 
was exposed freely and without any preparation, and was placed on the eastern 
side of the coming-in line ; the other of the two sets (No. 3 marked • • •) was 
coated' ail over with boiled coal-tar, laid on the iron when hot, so as to 
protect it from all corrosion. The third set of (6) bars (marked No. 1 •) was 
laid upon wood sleepers, chairs, &c., in the same way as the others, but were 
placed aside by themselves in the middle of the road between the two lines 
of railway, without any preparation, and freely exposed to corrosion, but not 
travelled over. 

All three setsof bars before being laid down or coated were heated in a boiler- 
maker's oven to a bright red heat, to remove all rust bya scale, leave their sur- 
faces perfectly uniform and alike, and were permitted to cool slowly without 
any blows, and in a horizontal position, so as to have as little permanent mag- 
netism as possible. 

Thus arranged the three sets of bars stood upon the line in the following 
order : 



Fiff. 1. 



ON RAILWAY BAR CORROSION. 

ohtt tj-avrllerZ Dt/ey N» I. mnrKeil(») 

N°g markeiM 



89 




N?3 'marheA(m) 



Coal Jarred- 
1 ^ t!'!?!f:", Airerhon of tmvn,s inohen 



j^' to Sydney Parade 



Thus the set No. 3, tarred over, is exposed to abrasion alone. The set 
No. 2 is exposed both to corrosion and abrasion ; deducting therefore the 
amount of the former from the latter, we get the amount of corrosion alone 
of the rails in use, and are enabled to compare this with the amount of cor- 
rosion of the set of rails No. 1 out of use, and thus at once to ascertain the 
difference, if any exists, and to determine the amount of abrasion for a given 
weight of traffic, of which returns are kept by the Dublin and Kingstown 
Railway Company. 

Half-sized section of Dublin and Kingstown Rail, taken accurately from a filed 
sheet-iron template of those experimented on, Sept. ISi*. 




Part of memel sleeper. 



^ The Dublin and Kingstown rails were made at the works of John Bradley 
and Co. of Stourbridge, and profess to be according to the specification of 
the Company's Engineer of 1833, viz. " Exterior surface of best 
rolled iron previously hammered, and the interior of the best 

or» P"'idled iron previously hammered, the proportion being two 

S. f parts of the former and five parts of the latter, and branded as in 

^-^ ^-^ margin." 

The dimensions as to surface, &c. of the rails is as follows, in accordance 
with the foregoing section : — 

Total perimeter of the rail = 11 -5 inches: 

Total surface per yard running=36x 11-5=414 sq. ins.=2-88 sq. ft. 



90 «BPORT— 1849. 

Total surface in contact with the wheels= 1-5 in. x 36=54 sq. in. per lineal 
yard of rail. 

Total surface iu contact v/\\\i filling jyieces beneath, and hence partially 
protected from corrosion, is=r7 in. X 36=61*2 sq. in. per lineal yard. 

Besides this there is the surface covered by the chairs and wedges, which 
partially but very slightly prevent corrosion, water finding its way between 
iu wet weather very readily. There is one chair at every three feet, which 
covers about twenty-four square inches, including the wood wedge. The 
meeting-chairs at every fifteen feet cover twice this. 

The top surfaces of the rails which are run upon appear to corrode 
scarcely at all, owing to the fine polish preserved by the rolling of the wheels ; 
if it be assumed that neither this top surface corrodes nor the bottom surface 
covered with the filling slip, then 

The total surface per yard lineal exposed to corrosion is=4'14 sq. ins.— [ 

(54'+61*2)=298-8 sq. ins., and the uncorroded surface=(54' + 61*2) 

= 115"2 sq. ins.=2"08 sq. ft, or the corroded is to the non-corroded 

surface per yard, as 298*8 : 115'2, or as 2-59 : 1 ; 

omitting any account of the surfaces covered by chairs, which are common 

to all the three sets, and do not prevent the corrosion materially beneath. 

But if the top or running surface of the rail be supposed to corrode equally 
with the sides, then 

The total surface per yard exposed to corrosion is=4'14 sq. ins.— 61*2 
=352*8 sq. ins., and the corroded is to the uncorroded surface per 
yard as 352-8 : 61*2, or as 5*76 : 1. 

The set No. 1, not travelled over, corrodes on the top as well as sides, and| 
hence exposes to corrosion per lineal yard, 414— 61*2=352"8 sq. ins. 

The weighings of the tiiree sets of railway bars took place for the first ex-j 
perimenton 24th of March 1841 : they were previously marked, as mentioned! 
above, (•), (••), (•• •), with a centre punch near one end on the side of the] 
bar, and each bar of each set numbered from 1 to 6. 

The weighings of the coal-tarred set were of course made before the ap- 
plication of the varnish, in applying which care was taken not to heat the bars] 
so as to scale them or to abrade, or in any way alter their weights. 

The weighings were made under my own eye, by David James, an intel- 
ligent workman, with a beam about six feet long, sensible when loaded with! 
one rail to about 2 ounces avoirdupois, or yJg-^th of the load in one scale, orl 
gg'gp th of the whole load. Four accurately adjusted half-hundred weights of I 
cast-iron, varnished over, prepared from the brass standard wei'e used, andf 
retained for use again on subsequent removal of the rails, and the other] 
weights were accurate brass standard avoirdupois weights of my laboratory. 

Each rail was weighed separately, and the weights were checked by myself.] 

The following table gives the data and numerical results df the first seriesj 
of experiments. 

All three sets. No. 1, No. 2 and No. 3, were laid down, and the traffic o| 
the second day of July 1841 was the first that went over them. 

They M'ere all taken up again and reweighed on the 30th of Aprill842j 
being exposed to corrosion and trafliic for an interval of 303 days. 



ON RAILWAY BAR CORROSION. 



91 



i Table No. 1. — First set of Experiments, Dublin and Kingstown Railway: 
rails traversed from July 2, 1841 to April 30, 1842 only : period 303 days. ^ 



How exp 
&c. 



Total weight 

of each rail 

when exposed. 

July 2, 1841. 



Total weight 

of each rail 

whenremoved, 

April 30, 1842, 



Gross weight 

of I he set 

when laid 

down. 



Gross weight 
of the set 
when re- 
moved. 



Total loss 

of weight 

in each 

set. 



Firstdif- 
ference 
= corro- 
sion in 
use. 



Second dif. 
=diff. be- 
tween cor. 
in and out 
of use. 



Set No. 1. 

In middle of 
line, and not 
travelled over. 

Corrosion 
alone. 



cwt. grs. 

2-f 15,385 
2+15,175 
2+ 1,845 
2+14,875 
2+ 3,900 
2+32,375 



cwt. grs. 

2+13,125 
2+13,125 
2- 1,750 
2+13,125 
2+ 1,750 
2+28,875 



9,491,555 



9,476,250 



15,305. 



Set No. 2. 

On the East 
side of Up 
Line. 

Corrosion 

and 
abrasion. 



2+12,250 
2+ 7,885 
2+17,500 
2+13,410 
2+29,975 
2+41,750 



2+ 6,890 
2+ 1,970 
2+12,142 

2+ 7,875 
2+21,875 
2+40,250 



9,530,770 



9,499,002 



31,7681 



Set No. 3. 

On the West 
side of Up 
Line. 

Coal-tarred. 

Abrasion only, 



2+ 7,356 
2+23,070 
2+ 3,750 
2+ 2,950 
2+21,830 
2+11,900 



2+ 3,425 
2+18,775 
2- 1,275 
2- 875 
2+16,550 
2+ 8,750 



9,478,856 



9,453,350 



25,506 



6262 



9043 



We are enabled to draw the following conclusions from this Table No. 1 : — 
1st. On thirty lineal yards of rail in use, the amount of abrasion is=25,506 

grs. in 303 days=30,725 grs. per annum, or at the rate of .^Q725_ ^o24*16 
grs. per yard per annum. ^^ 

The following is Mr. Bergin's statement of the amount of traffic which 
passed over the line from 2nd July 1841 to the 30th April 1842. 
Passengers. — 1 841 . 

July 67,172 

August 98,540 

September 67,901 

October 52,234 

November 39,355 

December , J6,809 

Total, exclusive of Subscribers 362,011 

Add Subscribers 91,745 



§0 REPORT — 1849. 

184-2. 

January 37,674< 

February 35,534 • 

March 42,509 

April 53,211 

Total, exclusive of Subscribers 168,928 

Add Subscribers 23,226 

Total of passengers in 303 days 64-5,910 persons — 

which, divided by 15, is = 43,061 tons. 

Engines and Carriages. 
No. of trains in all=10,528=same number of engines and tenders 

at 12 tons each =126,336 tons. 

No. of 1st class carriages = 10,528 
No. of 2nd class carriages =33,427 
No. of 3rd class carriages = 30,364 

Total of carriages=74,3l9 at ?>\ tons each = 141,537 tons. 
Gross weight of engines and carriages. . , . 267,873 tons. 
Hence the total gross traffic in carriages and passengers 

in 303 days is =310,934 tons. 

But a quantity of luggage and parcels are carried on 
the line of which no correct account is kept ; assuming 
this at an average of lOlbs. for each passenger, which 

645910 X 10 
will probably be about the truth, we have = 2,883 tons. 

303 days' total traffic 313,817 tons. 

or 378,030 .38 tons per annum. 

But as the load is uniformly diffused over both sides of each set of rails, 
only one-half the above load passes over any one given length of rail — 

or il^=189,015 tons, 

the passage of which produces an abrasion of 1024*16 grs. per yard per 

annum. Hence -,^^' ^ =0-00542 grs. per ton per yard, 

189015 
or 1760 X •00542=9-5392 grs. per ton per mile. 



There were 10,528 trains passed over the rail in 303 days ; assuming these 

uniformly diffused over the 24 hours, it is — — — -^ = ^ -447 train per hour ; 

but as the trains only travel from 6 o'clock a.m. to 10 o'clock p.m., or 16 
out of the 24, it is at the rate of 2*171 trains per hour, or rather more than 
one every half-hour. This is probably as fast as locomotive trains are likely 
to travel constantly on any line ; but the actual iveight of each train will 
materially affect the amount of abrasion, as there can be no doubt that at 
some certain weight the substance of the iron would be ruffled and disinte- 
grated by the great pressure rolling over it. 

We can determine in this case the average weight per train, as follows : 
viz. 43,061 tons of passengers + 2883 tons of luggage 
_ 45944 _^.«5g ^Qjjg of passengers and luggage per train, 

10528 trains, 

and tons of engines and carriages=25"44 tons average per train. 

10528 trains. 



ON RAILWAY BAR CORROSION. 93 

Hence the average gross weight of each train is=29'8 tons, or nearly 30 
tons. 

And the remarkable fact appears, that the useless load per train is to the 
iiseful as 25-44. : 4-36, or as 5*83 : 1, or nearly as 6 : 1 ; and that the abra- 
sion or destruction of rail relatively to the useless and useful load are in the 
same ratio. 

2nd. We deduce from this, that the absolute corrosion of a length of rail 
out of use to that of the same rail in use, or exposed to traffic, is in round 
numbers about, as 15-30 to 6-26, or that the difference in favour of the latter 
is 9-04 ; but it will be best to postpone a minute comparison of the rate of 
corrosion until we have the results of the further experiments also before us. 

While these experiments were in progress, it seemed very desirable to me 
to obtain a set of experiments made co-ordinately with the above, but upon 
a single line of railway where the traffic would be in both directions, viz. 
backward and forward over the same set of rails ; as from views suggested 
by Mr. Nasrayth, it was possible this might be an important element in the 
question. Mr. Nasmyth's views, which are briefly alluded to in my Third 
Report on the Corrosion of Iron, will be found more particularly detailed by 
himself in the following interesting letter to me, which I have his permission 
to publish ! — 

*' Bridgewater Foundry, Patricroft, 
May 19, 1842. 

"My dear Sir, — On my return from the continent I had the pleasure to 
receive your valued letter respecting the rusting and non-rusting of railway 
rails. I have not had any opportunity to obtain the exact comparative rate 
of oxidation under the two conditions, but so strikingly different is the oxida- 
tion of the one, as compared with the other, that a very slight glance will 
satisfy any one that they are under very marked and different influences, in- 
asmuch as, in the case of the Liverpool and Manchester, the rails of which 
have been laid and exposed to all the changes of wet and dry for upwards of 
five years, there is no more appearance of rust than merely a light-brown 
coating of mud-coloured water, more the result of the splashing of rain ; 
while in the case of the London and Blackvvall Railway, in which the car- 
riages travel alternately east and west on the same rail, the rusting is proceeding 
at that rate, that although they have not been laid two years, cakes of rust are 
falling from the sides of the rail, and the ground for 12 inches on each side 
of the rail is yellow with rust. This may be said to be mere ocular demon- 
stration, but to any one willing to be convinced, it is most satisfactory proof. 
I should be most glad to have my observations and theory on the subject 
brought to the most severe test ; but to do this would not be very easy, as 
to time and similar circumstances, all but the one in question, viz. the one 
way travelling versus the both ways alternately ; for to be a true experiment, 
we should have both bars of the same iron in the same place, only one 
travelled on in one direction, the other in both, and au equal amount of 
travel on each. The experiment required in that form might be tried by 
mechanical contrivance, hut then we know not as yet what is due to the cor- 
rection with so vast a length of rail as in the case of railroad ; but in the 
absence of any very delicate and ' scientific-like ' results I am fain to con- 
tent myself with the most striking difference, which is observed, or may be 
observed, by any one whose attention is directed to the subject. I may also 
mention, that on the Liverpool and Manchester line, all the sidings, as they 
are called, i. e. those parts of the rail which serve for backing trains into 
when it is desired to permit others to pass them on the same line, — that all 



94 



REPORT — 1849. 



such sidings are rusting naost rapidly ; it is tlie sides of the rail I hold to as 
proof, as such sides are in both cases removed from any friction. I may also 




Sidmj/ 

name that even the kei/s and chairs partake of the rusting or non-rusting in- 
flence, as the case may be. 

" I have had no means as yet to ascertain whether my conjecture is right or 
otherwise ; but I consider tiie rolling of the wheels in one direction to confer 
or induce a magnetical condition on the rails, in the same manner as in the 
case of inducing magnetism or magnetical property on a piece of iron or 
steel, by the ordinary method of passing the parent magnet along the iron 
bar, thus : 



^ 



rr^ 



Fig. 4. 



LTII 



U 



F^ 



The subject is, I think, a very interesting one, and well-worthy of attention, 
as it may tend to illustrate, on a most grand scale, some of the pure results 
of the delicate investigations which I doubt not you are familiar with, both as 
to what has been brought to light by others as well as yourself. If there 
be any further questions I can answer, you may command me at all times, as 

" I am most sincerely yours, 

" Hobert Mallet, Esq." " James Nasmyth." 

The Ulster Kailway between Belfast and Portadown, which was at that 

time a single line on the wide gauge, with a bridge rail of 521bs. per lineal 

yard as per fig. 5, half-sized section given, and without any chairs, and resting 




on longitudinal wood sleepers, presented an excellent position for this expe- 



ON RAILWAY BAR CORROSION. 



95 



riment, and on my writing to Mr. John Godwin, C.E., the Engineer of the 
line, he at once acceded to my wishes, and undertook the experiment. The 
following table gives its results, which are not as satisfactory as could be 
desired, owing to some circumstances which are unexplained, and which 
induced Mr. Godwin himself to consider the experiments in that light. 

The two following letters relate to this, and show that care appears to have 
been bestowed on each step of the process. The only error I am able to 
remark is, that one-half of the rails B, intended to be exposed to corrosion 
only, were by some mistake coated to prevent corrosion ; hence in deducing 
the results of the experiments I have been obliged to double the loss on the 
three uncoated rails 13, so as to get an approximation to the truth. 

" Belfast, 8th September 1843. 

" Dear Sir, — I send you enclosed the result of the experiment on the 
rails which we laid down in June 1842. You will observe that they were 
taken up in June last, and I would then have sent you the particulars had 
they not appeared so unsatisfactory. I cannot account for the great difference 
in the loss of weight, for we were very careful in weighing them. The 
quality of the iron could scarcely have made the difference ; however, I send 
you the particulars, and you can draw your own conclusions, 

" B, 4, 5, 6, were coated, and of course lost nothing. 

" I am, dear Sir, sincerely yours, 
" Robert Mallet, Esq." " John Godwin." 

" Belfast, 14th November 1844. 
" Dear Sir, — In reply to your questions relative to the account of the 
experiments on the corrosion of iron rails which I furnished you with, I beg 
to say, that the rail not travelled on was the centre rail in the middle of the line ; 
they were weighed with the same beam and weights as when put down ; the 
weights were properly adjusted; the beam was sensible to a quarter of an 
ounce ; the rails were weighed separately. 

" I am very sincerely yours, 
" Robert Mallet, Esq." " John Godwin." 



Fis. 6. 




The direction in azimuth, in which the experimental rails were laid upon 
the Ulster Railway, was north-east and south-west, 38° 13' east of north by 
compass, as in diagram above. 



96 



REPORT 1849. 



Table B. deduced from Mr. Godwin's Experiments on the Ulster Line, laid down 
June 15, 1842, removed June 27, 184-3 : period 377 days. 



. 






Total 


Total 








First dif- Second dif. 


n 






weight 


weight 


Gross weight 


Gross weight 


Total loss 




= diff. be- 


e 




How exposed. 




when re- 


when laid 


when 


of weight in 




ween cor. 


2 






posed of 
each rail. 


moved of 
each rail. 


down. 


removed. 


each set. 


in use. 


n use and 
3Ut of use. 








2 


• 


^ 


~ 


i 


E 




--• 






grs. 


grs. 


grs. 


1 





Set No. 1. 


2 


3 


22 


U 


2 


3 


21 


15 


One-half, viz. 
4. 5, and G rails 










2 


B. 


Betweeu the 


2 


3 


19 


»l 


2 


3 


19 


7i 












3 

4 




rails O not 
travelled over. 


2 
2 


3 
3 


22 
27 


4 
3i 


2 
2 


3 
3 


21 
27 



3* 


we must' double 
the loss to get 
an approximate 










5 




Corrosion 


2 


3 


19 


3 


2 


3 


19 


3 


result. 




41bs. 3oz. 






6 




alone. 


2 


3 


19 fl 


2 


3 


19 


1 


17.2.17.151 


17.2.15.14 


= 29,312 












1 

9 


00 
C. 


Set No. 2. 


2 
2 


2 

3 


18 
12 


15 

15^ 


2 
2 


2 

3 


17 
11 


12 
6 










3 
.1 




Exposed to 
traffic and 


2 
2 


3 
3 


27 
1 


11 
lOi 


2 
2 


3 
3 


25 




6 










■19,032 


5 




corrosion. 


2 


3 


17 


1.5 


2 


3 


15 


12 






nibs. 






6 




Uncoated. 


2 


3 


22 


7 


2 


3 


20 


6 


17.0.17.10 


17.0. 6.10 


= 77,000 


1 




1 
2 
3 


000 
A. 


Set No. 3. 

Exposed to 

traffic abrasion 


2 
2 
2 
2 


3 
3 
3 
3 


20 
22 
19 

20 


7 

9^ 

9 

.5 


2 
2 
2 

2 


3 
3 
3 
3 


19 
21 
19 
20 


5 
7 
2 








■ 48,344 




i; 




only. 


2 


3 


2.5 


.5i 


2 


3 


25 









41bs.Hoz. 






6 




Coated. 


2 


3 


21 


5i 


2 


3 


20 


8 


17.2.17. 9i 


17.2.13. 8 


=28,656 


J 





On examining this Table B, it appears that — 

1. The absolute loss from abrasion only is =28,656 grs. 

2. The absolute loss from corrosion only is=29,312 grs. on the rails not 
travelled over ; and 

3. The absolute loss from corrosion only 13=48,344 grs. on the rails ex- 
posed to wear of traffic. 

Hence in this case the corrosion of the rails out of use is less than that 
of the rails in use in the ratio, in round numbers, of 29*3 to 48*3, contrary to 
the received notion. 

As doubt rested on these results, owing to the circumstances already 
detailed, I determined to lay down a fresh set of prepared rails upon the 
Kingstown Railwaj', and subsequently another set upon the Dalkey Atmo- 
spheric Line, which, being a single line, stood in the same predicament as 
the Ulster Railway. 

One of the greatest difficulties attending experiments of this character, 
consists in the extremely small amount of weight to be determined (namely, 
the small loss by corrosion, even in a prolonged period), compared with tlie 
weight of the rails themselves, and the great absolute weight of the latter 
demanding balances of great strength, which are very difficult to be given 
the requisite sensibility. Where balances only competent to weigh one length 
of rail at a time are used, as in the case of Experiment No. 1, then the 
several sources of inaccuracy in each operation of Aveighing are multiplied 
by the number of rails weighed. As, therefore, the error of large balances 
does not increase quite as fast as the size of the instrument is magnified, it 
appeared advisable to obtain means of weighing several lengths of rails at 
once or together ; and for this purpose new standard weights were required, 
as well as new balances. 

The standard, namely, a brass authorized copy of the standard 56lb3 
weight, in the custody of the Corporation of Dublin, which is under- 
stood to be a true duplicate of that formerly in the Exchequer Office, 



ON RAILWAY BAR CORROSION. 97 

London, was obtained prior to Experiment No. 1, and was now again used 
to adjust fourteen cast-iron 56lbs. weigiits by, so as to enable 7 cwt. of rails 
to be \reighed at once. These cast-iron weights, prior to final adjustment, 
were coated with a thin covering of copal varnish, to preserve them from 
corrosion, until again called into use, after the lapse of two years. They 
were handled with leather slings to avoid abrasion, and preserved in a per- 
fectly dry place, and checked against the brass standard again before being 
used to weigh the rails after their removal. A steel beam of 36 inches 
in length was prepared and carefully adjusted by Mr. Yeates, instrument- 
maker, Dublin, by M'hich these weights were adjusted. It was sensible to 
20 grs., with 56lbs. avoir, in each pan, or to soloo^h P^"^*^ ^^ ^^^ whole 
load. It turned in all its bearings on hardened steel edges, and was found a 
most satisfactory and accurate instrument. 

A large beam was also prepared and carefully adjusted, whose length was 
eight feet, and whose strength was such as to be capable of weighing three 
lengths of rails at once, or of sustaining a load of above 12 cwt. This 
beam was of wrought iron, turning on hardened steel knife-edges, and with 
means of gradually bringing the load upon the beam without jar or vibration. 

When loaded with three rails and their counterpoise, this very large beam 
was found to be sensible to 500 grs., or to g^Va^ P^'^'' ^^ ^^^ S'"'^^^ ^"^'^ ' 
and could have been made still more so if requisite. It is probably the 
largest and most accurate beam ever made. 

Both this and the smaller beam were tolerably equibrachial ; but to avoid 
any error from this source, double weighings were made in adjusting the 
weights, and one end of the large beam was marked, and the rails always 
placed under it, the counterpoise being at the opposite end. 

This may appear a tedious description of an unnecessary amount of care ; 
but when it is recollected that the question to be determined relates to a 
weight of not much more than a single pound in a gross load of nearly 
14001bs., it will be seen that any inaccuracy in the weighings would mate- 
rially modify, or wholly vitiate the results ; and it is to the accumulation of 
slight errors of this sort, and probably more particularly to want of equibra- 
chiality in the beams used, or want of attention to always weighing at the 
one end, that I attribute the want of consistency of the results obtained on 
the Ulster line of railway. 

In order also further to increase the accuracy of the result, I proposed to 
allow a longer period to elapse before again removing the rails from the line 
when laid down. 

The same set of eighteen rails divided into three classes of six each, which 
had been used in the first experiment on the Kingstown line, were now again 
brought into requisition. They had lain since the former experiment hori- 
zontally under cover in a dry place, and had acquired a very slight coat of 
red rust. They were all placed in a boiler-maker's oven, and exposed to a 
bright red heat, and then permitted to cool, without being exposed to any 
blows or jars, in a horizontal position and under cover. They had all now an 
uniform coat of black oxide (Hammersehlag), very thin and adherent, were 
pretty free from magnetism, except that due to terrestrial induction ; and in 
this state they were all weighed, and the weights registered, each rail having 
received a permanent mark at one end. 

The six rails to be exposed to abrasion only, were now heated horizontally 
to about 400° Fahr. and coated with boiled coal-tar, which rapidly dried into 
a tough japan varnish. 

The weighings were made on the 10th October 1842; and on the 18th 
October 1842 they were placed upon the up line of the Dublin and Kingstown 
1849. H 



98 REPORT — 1849. 

Railway, at the same place, and in precisely the same order as before, and 
travelled over for the first time on that date. 

They remained exposed to traffic and corrosion for two years, and on the 
18th October IS^^ were removed from the line and brought home for ex- 
amination and weighing. Prior to this the beams and the standard ^'eights 
were again examined as to their accuracy and adjustment, which were found as 
perfect as before. I prepared to weigh the rails in the same order as before. 

These rails having been divided into three classes or sets, viz. — 

No. 1. Not coated, exposed to corrosion alone and not to traffic. 
No. 2. Not coated, exposed to corrosion, and also to the abrasion 
of traffic. 

No. 3. Coated with coal-tar and exposed to abrasion of traffic, but 
protected from corrosion, — 
presented, when removed, the following appearances : — 

The set No. 1 had a very dark red rusty colour, and an obvious scale of 
adherent rust all over, which a closer inspection, and on passing the point of 
the finger over the surface, proved to be papular or tubercular, and nearly 
uniformly so all over, each separate circular tubercle of oxide being about 
•j^yth of an inch in diameter. Tiie spaces between these were less dark- 
coloured, or huffish; this aspect was quite uniform over every part of the 
rails, except where they had been in contact with the chairs. 

The set No. 2 had no scale of rust on the surface, but a perfectly uniform 
dark buff or reddish buff thin dusty coating of oxide all over the sides and 
edges ; the top surface was bright and polished by traffic, but the wear was 
not perceptible in dimension ; the lower surface, where in contact with the 
wood filling slips, on the sleepers was of a deeper colour, and where in con- 
tact with some parts of tiie chairs was bright and polished from the effects 
of jarring or vibration produced by traffic. There was no loose rust what- 
ever on any part. 

The set No. 3, which had been coated with coal-tar, were found bright 
and polished, like No. 2, on the top edge, where borne upon by traffic. The 
coal-tar varnish was fresh and sound everywhere else, and no rust had taken 
place, nor any scaling off from any part of the bars. The surface, how- 
ever, until it was washed clean, presented a uniform tint of yellowish brown, 
arising from the fine particles of rust from the other rails, and probably also 
from the wheels, of passing trains being blown upon the coal-tar coating, and 
washed upon it by rain, &c. 

Prior to being cleaned for weighing, the whole of these rails were examined 
as to their magnetic condition. The results ascertained will, however, be 
best reserved for a subsequent part of this Report. 

The sets of uncoated rails, Nos. 1 and 2, were rubbed briskly with a fine 
wire brush until all adherent rust was removed, and then finally cleaned 
with dry cloths. 

The set No. 3 was exposed to a heat of about 700° Fahr. over a charcoal 
fire, until the Avhole of the coal-tar coating Avas burnt, and removed as char- 
coal dust by the brush and cloth. The weighings were then made in the 
same order and way as before ; and the following Table No. 2 gives the 
results. 

The rails, after being cleaned and weighed, presented all over a light red- 
dish black tinge, perfectly uniform, and free from any scaling, or other indi- 
cation of unequal action. 



ON RAILWAY BAR CORROSION. 



99 



Table No. 2. — Second set of Experiments on the Dublin and Kingstown Rail- 
way: rails traversed from Oct. 18, 1842 to Oct. 18, 1844-: period 730 days. 



How e: 
&c 



Weights of 
rails as weigh- 
ed together 
when exposed 



Set No. 1. 

At one side 
of line O j 
nottravelled"] 



Con'osion 
alone. 



cwt. grs. 
6+29,750 

6+47,250 



Set No. 2. 

On tbe East 
side of the 
Up Line 

Corrosion 

and 
Abrasion. 



Set No. 3. 

OntheWest 
side of Up 
Line. J 

Coal-tarred. 

Abrasion 
only. 



Weights of 
rails as weigh- 
ed together 
when removed 
and cleaned. 



cwt. grs. 

6+21,875 
6+42,000 



6+22,750 



6+77,875 



6+23,187 



6+27,125 



Gross weight 

of the set 

when laid 

down. 



6- 3,500 



6+51-625 



6+ 437 



6+ 2,188 



Gross weight 
of the set 
when re- 
moved and 
cleaned. 



9,485,000 



9,508,625 



9,458,312 



9,471,875 



9,456,125 



9,410,625 



Total loss 
of weight 
in each 



First dif- 
ference 

= corro- 
sion in 
use. 



13,125. 



52,500" 



47,687. 



Second dif. 
= diff. be- 
tween cor. 
in and out 
of use. 



4813 



8312 



From these results we learn, that in a period of 730 days' exposure, — 

1st. The absolute abrasion from traffic on the six rails was 47,687 grs. avoir. 

2nd. The absolute corrosion of the six rails in use, or exposed to traffic 
and to corrosion, was 4813 grs. avoir. 

3rd. The ratio of abrasion to corrosion on the rails in use is therefore nearly 
in the ratio of 47"7 to 4'8, or in round numbers as 48 to 5, or nearly 10 to 1 . 

4th. The absolute corrosion of the six rails out of use, or not travelled 
over, was 13,125 grs. avoir. 

5th. The ratio of the abrasion of the rails in use to the corrosion of the 
rails out of use is nearly as 47*7 to 13*1, or in round numbers about as 4 to 1. 

6th. The difference (absolute) between the corrosion of the rails in use 
and out of use is =8312 grs. avoir. Hence 

7th. The ratio of the corrosion of the rails in use is to that of the rails out 
of use as 48*13 to 83*12, or in round numbers as 8 to 14. 

h2 



loo REPORT — 1849. 

There isi lerefore on this second experiment a distinct corroboration of 
the result of the former Table No. 1, viz. that there is a real diminution of 
corrosion in the rails, due to traffic. The absolute amount of dift'erence is 
less however in this second experiment than in the first. By Table No 1 it ap- 
pears that the ratio of the corrosion of the unused, to that of the used rails, was 
as 15*30 : 6*06 ; but in the present case we find the ratio to be as 83-12 : 4-«-l 3, 
or as 1 to 2'5 in the former, and 

1 to 1*7 in the latter. 
Hence the difference is a decreasing one, the causes of which we shall again 

refer to. . , - , r n 

The whole three sets of rails in this expenment were weighed carelully 
before being cleaned just when removed from the line, and without any ad- 
herent rust or other matter being shaken off from them, and, as already stated, 
again weighed after having been brushed and cleaned. The difference 
showed the amount of adherent oxide attached as a scale to the uncoated 
rails, and of varnish coating on the others. 

The weight of detached matter was as follows : — 

No. 1. Uncoated, not travelled over 5,250 grs. 

No. 2. Uncoated, exposed to traffic 1,313 „ 

No. 3. Coated, and exposed to traffic .... 11,375 „ 
consisting all of coal-tar and dust. 

From this it is apparent that the coat of adherent rust upon the unused 
rails was on equal surfaces to that on the rails exposed to traffic, as 52*5 to 
1 3*1, or that the adherent rust on the unused rails is nearly four times as 
thick as on the rails exposed to traffic, proving that the oxide formed on the 
latter is constantly shaken off" by the vibration of passing trains. 

It is now desirable to give the amount of traffic which passed over the rails 
during the period of the last experiment, viz. — 

Traffic in tons passed over the Dublin and Kingstown Railway between 
18th October 184-2 and 18th October 1844, per T. F. Bergin, Esq. 

Tons. 

4,041,075 passengers at 15 per ton 269,405 

59,243 engines at 15 tons each 888,645 

437,791 coaches, average 2>\ tons each 1,532,268 

Total in both directions 2,690,318 

The traffic being precisely equal up and down, and the passengers Tons, 
very nearly so, say for gross traffic over experimental rails one- 
half the above= _• • 1,345,159 

To which add for ballast brought over experimental rails during 

the two years, and for luggage 10,000 

Total load transferred over experimental rails= 1,355,159 

or 677,5791 tons per annum. Only half this, however=677,579^ tons in 
the two years, or 338,789| tons per annum, traversed each length of ex- 
perimental rails. 

This latter weight produced in the two years an absolute abrasion on 30 
yards of rail of 47,687 grs. avoir., or of 23,844 grs. per annum, which is 
nearly 795 grs. abraded per yard per annum, or an abrasion of iron amounting 
to -00235 gr. per ton per yard, or 1760 x •00235=4-136 gr. per ton per mile. 
The absolute abrasion is therefore less in this second experiment than in 
the first, in the ratio of 4 to 9-5 in round numbers, proving that the upper 
surface of the rails gradually alters in texture, and gets hardened by the 
rolling over it of the loads, so as to be less and less abraded in proportion 
to the load passed. This fact, however, can only apply to cases where the 



ON RAILWAY BAR CORROSION. 



101 



loads are light enough not to disintegrate the surface of the rail, and to 
places where the brakes are not applied. On many of the lines of heavy 
traffic in these kingdoms at present the incumbent loads seem from the very 
first to break up the molecular arrangement of the upper flange of the rail, 
and hence induce a gradual increase instead of decrease of abrasion ; while 
in places where the brakes are habitually applied, the rails are ground away 
in flakes with great rapidity, those at some of the stations on (he Kingstown 
line having one-half the upper flange of the rail cut away in three or four years. 

Through the kindness of Capt. Larcom, R.E., I am enabled to give the 
amount of rain which fell in the basin of Dublin during the period occupied 
in this last experiment. The results are taken from the meteorological re- 
gister kept at the office of the Ordnance Survey, Mountjoy Barrack, Phoenix 
Park, Dublin. The rain-gauges are situated on a plain 1 81-8 feet above the 
Ordnance datum, or low water of spring-tides, at Dublin Bay lighthouse, and 
have no hills in the immediate vicinity. The annual fall of rain is pretty 
constant at Dublin ; and hence these tables may be viewed as sufficiently 
applicable to all the experiments related in this report. 

The average rain, from several years' registry, is 33-1 15 inches by Ordnance 
gauge, and 29-616 inches by that of the Royal College of Surgeons in the 
city of Dublin, and at an elevation of 51'72 feet above the Ordnance datum. 



Months. 


1841. 


1842. 


1843. 


1844. 


January 

February 

March 

April 

May 

June 

July 

August 

September .... 

October 

November .... 
December .... 


1-767 
1-210 
1-635 
1-082 
2-349 
2-043 
2-763 
2-951 
1-489 
4-810 
2-781 
3-245 


1-147 
2-860 
2-314 
0-996 
3-673 
2-256 
3-183 
1-580 
3-451 
1-734 
5-234 
1-126 


1-886 
1-561 
1-704 
2-984 
4-639 
2-887 
2-246 
2-025 
1-235 
3-918 
2-543 
0-414 


1-726 
2-517 
2-058 
1-207 
0-295 
1-479 
2-039 
3-634 
2-847 
2-824 
4-992 
2-412 


For the year . . 


28-125 


29-554 


28-042 


28-030 



The mean barometric pressure for the years 1842 and 184?3, corrected and 
reduced to 32° Fahr. at Dublin, was — 

184.2 29-926 inches, 

1843 29-870 inches, 

the cistern of the barometer being 24'5 feet above the Ordnance datum ; and 
the above numbers being deduced from 3600 observations. 

For these data I am indebted to Professor Lloyd, who obligingly extracted 
them from his results obtained at the Magnetic and Meteorological Observa- 
tory of Trinity College, Dublin. 

The mean pressure at Greenwich, where the barometer is 159 feet above 
the level of the sea, for the years was — 

1841 29-687 inches, 

1842 29-832 inches, 

the instruments being strictly comparable. 

The relations to the corrosion of iron, of variable quantities of rain and 
of atmospheric pressure may be referred to in my Third Report on the 
Corrosion of Iron, Trans. British Association (sects. 286, 305). 



102 



REPORT — 1849. 



The same sets of rails that had been taken up from the Kingstown line in 
October 1S4'4' were laid by in a dry place, passed through the same ordeal 
of heating to a bright red, cleansing and coating (one of the sets) as before; 
and on the 7th January 1845, the weighings being all completed, the three 
sets were again laid down on the Dalkey atmospheric single line railway, at 
a straight part of the line near the Dalkey terminus, in quite the same way 
and order as before, and fastened in the same way, the set of unused rails 
being laid at one side of the line of way. The direction of the railway at 
this place is nearly W.N.W. and E.S.E., corrected for variation ; and the 
traffic is here in both directioiis over the same rails. 

The rails were continued on this line for the long period of four years; 
and on the 7th January 1849 were removed and weighed after prior exami- 
nation as to state of surface and magnetism, &c. The results are given in — 

Table No. 3. — Third set of Experiments on the Dalkey Atmospheric Rail- 
way: rails traversed from W.N.W. to E.S.E. and the reverse: period from 
January 7, 1845 to January 7, 1849 = 1460 days. 



Z 


S . 

is 

=5 


How exposed. 


Weight of 
rails as weigh- 
ed together 
when exposed. 


Weight of 
ails as weigh- 
ed together 
when removed 
and cleaned. 


Gross weight 

of the set 

when laid 

down. 


Sross weight 
of the set 
when re- 
moved and 
cleaned. 


Total loss 

of weight 

in each 

set. 


First dif- fc 
ference 

sion in 
use. 


econd dif. 
=difr. be- 
:ween cor. 
n use and 
3ut of use. 


1 

2 

3 
4 
5 
6 


.;.. 


Set No. l.~ 

In middle 
of line, and | 
not travel- 
led over. 

Corrosion f 
alone. 


cwt. grs* 

6-f 8,500 
6-1-28,625 


cwt. grs. 

6- 9,250 
6-f 13,125 


grs. 

9,445,125 


grs. 

9,411,875 


grs. 

33,250... 


grs. 


gra. 






1 

2 
3 
4 
5 
6 




Set No. 2. 

On the East 
sideofLine._ 

Corrosion 

and 
abrasion. 


6-14,500 
6-f39,375 


6-58,750 
6 


9,432,875 


9,349,250 


83,625" 




. 8800 






1 
2 
3 
4 
5 
6 


••• 


Set No. 3. 

Ontlie"^Vest 
sideofLine. . 

Coal-tarred. 

Abrasion 
only. 


. 6- 9,625 
^ 6- 9,625 


6-44,650 

Broken out 

-f 990 

6-35,000 

Broken out 

-f 235 


9,388,750 


9,329,575 


59,1 75_ 


24,450 


J 



ON RAILWAY BAR CORROSION. 103 

On examining this table weareenabled todeduce the following results, viz. — 

lot. The absolute abrasion during the whole period of 1460 days on the 
six rails is 59,175 grs. avoir. 

2nd. The absolute corrosion on the six rails in use, and exposed to traffic 
in same time, is 24,450 grs. avoir. 

3rd. The ratio of abrasion to corrosion on the rails in use is therefore 
nearly in the ratio of 59*2 to 24"5, or about as 2'4 to 1. 

4th. The absolute corrosion of the six out of use and not travelled over 
was 33,250 grs. avoir. 

5th. The ratio of the abrasion of the rails in use to the corrosion of the rails 
out of use is therefore nearly as 59"2 to 33*3, or about as 1 '44 to 1, or 1^ to 1. 

6th. The absolute difference between the corrosion of the rails in use and 
out of use is 8800 grs. avoir. Hence 

7th. The ratio of the corrosion of the rails in use is to that of the rails out 
of use as 24*5 to 87'9, or nearly 88, or in round numbers as 3*14 to 1. 

Here again then we have corroborated the fact of a real difference in cor- 
rosion due to traffic, and again we find it a decreasing one as compared with 
the former experiments. 

We now proceed to give the amount of traffic on the Dalkey Atmospheric 
Railway during the four years of these experiments, as deduced from the 
records of the Company by Mr. Bergin at my request. 

The whole traffic up and down passed over the experimental rails. 

Traffic of the Dalkey Atmospheric Railway from 7th January 1845 to 23rd 

November 1848. 

No. of trains. I No. of coaches. I No. of passengers. 

86,972 I 296,048 | 949,636 

The average proportion of the classes of 2nd and 3rd class carriages is one 

of equality, one of the latter being always a piston carriage ; and the average 

weights are — Piston carriage 5 tons 1 cwt. 

Second class coach 3 „ 11 „ 

Third class coach 3 „ 6 „ 

And taking the passengers at 14 to the ton to allow for luggage, we have for 
the weights in the above time — 

1,166,155 tons of dead weight in trains 
67,831 tons of passengers. 
Total. . . . 1,233,986 tons of gross load. 
But the line was stopped on the 23rd November 1848 for repair, and 
worked by a locomotive. The estimated traffic for this period up to January 
7, 1849, is thus : — Tons. 

288 locomotives at 10 tons =2880 

214 second class coaches , . 760 

214 third class coaches 706 

4274 passengere, 14 per ton 305 

Total 4651 

Which, added to the foregoing, gives for the whole period of traffic — 

1,233,986 
4,651 
1,238,637 tons 
divided into 86,972 + 288=87,260 trains. The average weight per train is 
therefore only 14*2 tons. 

The total load transferred per annum on the average was 309,659^ tons. 
The half of this=154,829f tons was therefore transferred over each length 
of rail annually. 



104 



REPORT — 1849. 



The total abrasion on 30 yards of rail we have noted at 59,170 grs. in 
four years, or 14,792"5 grs. per annum, which again is equal to 493*08 
grs. per yard per annum. This is equivalent to '00318 gr. of iron abraded 
per ton per yard, or to 1760 X -003 18 =5-597 gr. per ton per mile, or 
nearly 5'6 grs. per ton per mile. 

This result corresponds closely with that of the second experiment on the 
Dublin and Kingstown line, from which we may remark, that altiiough the 
average weigiit per train in this instance is only about one-half that of the 
Dublin and Kingstown line, yet that the abrasion is nearly as great, proving 
that traffic over the same rails in both directions exercises a destructive effect 
upon the molecular constitution of the iron, which is equal with trains of a 
given w^eight to that produced by trains of double the weight always moving 
in the one direction only, or in other words, that ivith equal rolling loads 
t/ie destruction of the rails by abrasion is doubled by running the traffic in 
both directions over the same rails. Owing to the fact that the piston car- 
riage on atmospheric railways has to open the valve, there is rather more 
pressure exei'cised by this carriage upon the rails than is due solely to its 
weight, but this excess is so small as not to affect the question. Hence the 
excess of abrasion nuist be due to the motion in opposite directions con- 
tinually splitting up the topmost fibres of the iron, which have been partially 
laminated and rolled out by the former train in the contrary direction of 
motion. 

Having now arrived at the last of these prolonged experiments, we may 
combine the results into one table of the 1st and 2nd experiments on the 
Kingstown line, and of that on the Dalkey line, rejecting that on the Ulster 
as dubious, and reducing all the results to one common period of 365 days, 
or one year. 

Table No. 4. — Results of 1st, 2nd and 3rd Series of Experiments reduced 
to a common period of 365 days. 



Nature of the action on 
the rail. 


First Experiment 
on Dublin and 


Second Experiment 
on Dublin and 


Third Experiment 
on Dalkey Rail- 


Kingst. Railway. 


Kingst. Railway. 


way. 




grs. 


grs. 


grs. 


Abrasion in use .... 


30,725 


23,843 + 


14,794- 


Corrosion in use. . . . 


7,523 


2,406 + 


6,113- 


Corrosion out of use . 


18,436 


6,562 + 


8,312 + 


Difference between "1 
corrosion in use / 
and out of use. . J 








10,893 


4,156 


2,200 









The preceding are the absolute losses of weight upon 30 yards of rail in 
one year. 

The following are the first differences respectively between the abrasions 
and corrosions as given in the 1st, 2nd and 3rd experiments, i.e. differences 
between 1st and 2nd, and between 2nd and 3rd, viz. — 

1st and 2nd. 2nd and 3rd. 

Abrasion 6,882 904'9 

Corrosion in use 5,117 3707 + 

Corrosion out of use 11,874 1750 + 

These do not present a series, but we are enabled to conclude fromTable4, — 
1st. That the abrasion by traffic on the same rails constantly decreases in 
reference to the rolling load. 



ON RAILWAY BAR CORROSION. 



105 



It is probable that the rate of this decrease will be more and more slow, 
and at a certain point of hardness reached by the condensation of the iron of 
the rail due to the rolling load, it will become and continue constant. 

2nd. The corrosion both in use and out of use appears also to decrease 
gradually upon the Kingstown line. The absolute corrosion in botii cases is 
greater on the Dalkey line, owing to the increased dampness of the situation 
in which the rails were necessarily placed for experiment upon it, viz. iu a 
shallow cutting with wet bottom. 

3rd. The difference between the corrosion in use and out of use, which 
exists throughout all the experiments, is also a constantly decreasing one. 

For purposes of general comparison, and of comparison with the corrosion 
of rails made of other makes or qualities of iron than those of the present 
experiments, it will be convenient to arrange the following table of the 
amounts of corrosion, both in and out of use, reduced to one square foot of 
corroded surface, and for a term of one year. 

The total exposed surface of the Dublin and Kingstown rail per lineal 
yard, is=2'88 square feet, but from this we have to deduct the top surface 
of the rail, which is rolled over in contact with the wheels, and which, being 
preserved bright, does not corrode, being 1*75 inch wide, which leaves a 
net surface of corrosion of 2"4"i square feet per yard for the rails in use, and 
of 2'88 square feet per yard for the rails out of use as above. 

Taking the results of Table No. 4, therefore, we are enabled to deduce 
Table No. 5, which gives the corrosion in each case per square foot of sur- 
face of rail, and these results are then comparable with those of Table 15 of 
my Third Report on the Corrosion of Iron and Steel, &c., Transactions of 
British Association, and indeed comparable (by the aid of the standard bar 
as referred to in those reports) with all other results as to corrosion detailed 
therein, so that these experiments as to the corrosion of railway bars, may be 
hereafter extended or applied by others to rails rolled of any other make of 
iron whatever. 

Table No. 5. 



Nature of action on the rail. 


First Experiment, 
Dublin and Kings- 
town Railway. 


Second Experiment, 
Dublin and Kings- 
town Railway. 


Third Experiment, 
Dalkey Railway. 


Corrosion out of use"! 
per square foot of > 
rail per annum. ... J 

Corrosion in use, or"^ 
exposed to traffic per 1 
square foot of rail ^ 
per annum J 


grs. avoir. 
213-38 

103-04 


grs. avoir. 
76-00 

32-87 


grs. avoir. 
96-18 

83-53 


Differences 


110-34 


33-13 


12-65 





Thus again the differences show a constantly descending series. 

If we extract from Table 15, Third Report on Iron, British Association, a 
few of the amounts of corrosion there given per square foot of surface, and 
reduce them to a period of one year, the foregoing corrosions will appear in 
all instances remarkably less. 

The results of Table 15 are, however, not strictly comparable, as the iron 
there was exposed to the air and moisture of the City of Dublin, where the 
smoke and vapours, and excess of carbonic acid, close to the roofs and 



lOG REPORT 1849. 

chimneys, accelerate corrosion ; still the difference is so remarkable, as to 
induce the suspicion, that there are some forces engaged which more or less 
retard the corrosion of iron when exposed in railway bars, in every condition, 
i. e. whether travelled over or not. Thus in one year, the losses by corrosion 
on one square foot of surface of the following sorts of iron exposed in the 
City of Dublin, were — grs. avoir. 

2. Common Shropshire bar ISl^'lG 

3. Best Staffordshire bar lOlS-O-t 

4. Best Dowlais Welsh bar 990-00 

5. Low Moor boiler plate 932-40 

8. Faggoted scrap bar 622*80 

We now return to detail the examination made of the rails when just 
removed from the Kingstown Railway, as to their magnetic condition after 
the first exposure thereon, and also after their exposure upon the Dalkey line. 

For this purpose the railway bars were brought into an open piece of level 
ground, remote from any masses of iron or other causes of magnetic disturb- 
ance ; and at some considerable distance from where they lay, a triangle and 
purchase-blocks were so arranged, that any one bar could be suspended bj'- 
the middle of its length in a horizontal position ; the length of the bar being 
preserved either in the magnetic meridian or at right angles to it, or could 
be tilted up vertically, or in the line of the dip. 

Each bar was first placed horizontally in the magnetic meridian by a line 
parallel therewith, previously marked out on the ground by two distant ob- 
jects. A Kater's compass of delicate adjustment was now brought to rest, 
and then advanced slowly parallel with the bar towards the end facing the 
magnetic north, and the action of the bar on the needle noted. The compass 
was then brought back to the southern face or end of the bar, and the action 
also noted. The bar was then turned horizontally end for end, and similar 
experiments made ; and lastly, the bar being turned round 90°, and thus being 
at right angles to the magnetic meridian, similar trials were made for each 
end. By this means the induced polarity by terrestrial magnetism was made 
evident, and separated from the idio-polarity, or the magnetism permanently 
proper to the bar. 

Lastly, each bar was examined as to the position of the neutral point or 
points betwixt the poles, by carrying the compass slowly along its length 
■while the bar was at right angles to the magnetic meridian, and observing 
when the needle was neither deflected to the east nor to the west, but con- 
tinued to point to the magnetic north station mark, the point opposite to 
which was the neutral one. W'ith a longer needle of greater delicacy, and 
suspended within a glass cylinder from silk fibres, examination was made as 
to the state of polarity of each bar, with reference to the depth of the rail, 
the fop edge while in use being always uppermost and the bar horizontal. 

These experiments were made for every bar; it will not be necessary to 
describe the individual results in detail, but give them generally. 

T/ie set No. 1 , not travelled over, and exposed to coriosion alone. — When 
examined after exposure on the Kingstown line, they showed strong polarity 
by terrestrial induction, but very slight idio-polarity. Some of the bars, 
however, when placed in the magnetic meridian, showed a feeble permanent 
polarity, reverse to that of Fig. 7. 

the earth, i. e. to induction, . 

and more than one neutral 

point ; one bar, for exam- --^ i '^ j - — ^^ **\ - . n 

pie, showed three neutral ^-,_--2.o -x- 

points at a, h and c, and 

hence had eight poles with reference to length. 



---X-l -X—ti-T-.tl- 



ON RAILWAY BAR CORROSION. 107 

When this bar and some others were turned at right angles to the mag- 
netic meridian, and examined with the suspended needle moved vertically 
up and down before their extremities, the existence of two poles at each end 
of the bar was made evident ; thus the needle Fig. 8. 

was quiescent at a certain point in the depth 

of the bar when held thus opposite the end j 

of it, but was attracted or repelled in op- ^^ 
posite directions when above or below this ] 
point. 

This fact was subsequently ascertained to apply to all the railway bars ; 
that is to say, a railway bar when polar is a magnet of such thickness, that 
it presents poles at its solid angles, not only with reference to length, but to 
depth, these poles being always of unequal intensity, the bar being in fact in 
the predicament of a cube or large paralielopiped of iron when exposed to 
magnetic induction. Hence the bar last adverted to with three neutral points 
had in fact sixteen poles distributed along its length ; eight on the top and 
eight on the bottom flange or edge, and alternately of greater and of less in- 
tensity along the same edge, thus : — 

Fig. 9. 

§ § 1 

^ ? ...Lt ^ o^.^ c» 



These secondary poles, or those of depth, were not altogether due to ter- 
restrial induction, as they preserved their signs, though with diminished 
intensity, when the bar was turned upside down, i. e. when the top edge 
became the lower, the direction and ends of the bar remaining unmoved, but 
they are probably due to induction within the bar itself. 

Similar phenomena to the above present themselves in the same bars when 
examined after removal from the Dalkey line, as was to have been expected, 
there being no change in their condition in either case, viz. not having been 
travelled over on either line. 

The set No. 2, not coated, and exposed both to oxidation and to abrasion of 
traffic, when examined in the same way, after experiment on the Kingstown 
line, all proved to be powerfully magnetic with polarity ; the idio-polarity 
being almost in every case suflSciently intense to neutralize or reverse the po- 
larity of terrestrial induction. In almost every instance there were two 
well-defined poles at the extremities of the bars, with one neutral point 
between. 

In every rail the S. pole of the bar was found in the direction in which 
the traffic came in upon it, and the N. pole at that at which the traffic rolled 
off from it. Now the traffic passed over these bars in a direction from S.E. to 
N.W., and hence the direction of permanent polarity conferred upon the bar, 
coincides with the direction (in this instance at least) in which the traffic 
rolled over it. 

The same bars when examined after removal from the Dalkey line (where 
it will be remembered the traffic is in both directions from W.N. W. to E.S.E. 
and vice versa, and the polarity of the bars acquired on the Kingstown line 
having been afterwards destroyed by heating them all to redness), were 
found powerfully idio-polar ; some of the bars much more so than in the 
former case, so as to be able, Avhen brought into the direction of dip, and thus 



108 



REPORT— 1849. 



terrestrial induction made to aggrandize the idio-polarity, to lift and sustain 
a common sewing-needle ; they had all two well-defined poles at the extremities 
and one neutral point, but the poles were seldom of quite the same intensity. 

The set No. 3, viz. those coated with coal-tar and exposed to abrasion of 
traffic only, when submitted to a similar examination, present quite the 
same characters; each bar was powerfully idio-polar, with two well-defined 
poles of slightly unequal intensity and one neutral point, All the pheno- 
mena of terrestrial induction could of course be made evident with these as 
well as the other sets. 

What is very remarkable, the intensity of magnetic polarity was quite as 
great in those bars and in the set No. 2 after removal from the Dalkey line, 
where they were travelled over in both directions, as after removal from the 
Kingstown, where travelled over only in one. In the latter case however the 
direction of the poles of each bar, as it lay in the line of railway, was that 
due to terrestrial induction, i. e. the south pole of the bar faced the north 
pole of the earth and vice versa ; the opposite was the case with the bars on 
the Kingstown line of set No. 2, as already detailed. 

These facts are sufficient wholly to overturn the views suggested by Mr. 
Nasmyth, in his letter already given, as to the peculiar effects of traffic in 
one or in both directions. 

In connexion with this subject, I have also examined the magnetic con- 
dition of old wheels and axles that have run for a considerable time on rail- 
ways. In every case these ran more or less in both directions ; the results 
presented are very perplexing and variable, but in general I find the axle is 
more or less idio-polar. The wheel also is very often feebly idio-polar, the 
poles being at the nave and periphery ; but when a pair of wheels and their own 
axle stand on the rails in the usual position, the axle being idio-polar, then 
by induction from the axle and by terrestrial induction conspiring, a tolerably 
distinct polarity of the whole wheel i^ produced, the nave presenting a pole 
opposite to that of its own end of the axle, and a pole opposite to this being 



Fig. 10. 



found opposite the extremity 
of every spoke round the 
wheel-tire orperiphery: thus 
when the wheel is rolled 
along the rails where the lat- 
ter have been long in use and 
are themselves polar, the in- 
tensity varies with the posi- 
tion of the wheel over a given 
length of rail, and may be a 
maximum when the wheel 
rests over a joint beween two 
rails, viz. over the polar extre- 
mities of the contiguous rails. 

I endeavoured to ascertain whetiier the total intensity of the six bars consti- 
tuting the set exposed to abrasion only, or of the six bars exposed to abrasion 
and corrosion, was the greater, but not having a suitably mounted mag- 
netometer, I was unable to satisfy myself fully ; so far as my trials went, 
however, there seemed but little difference appreciable in either case, and 
that equally so whether the two diffierent sets were rolled over both ways, or 
only in one direction. 

I ascertained also that the polarity of each bar, as it lies in the line of 
railway, is somewhat increased in intensity by induction from the bar lying 
parallel to it in the opposite side of the railway line. This effect however 




ON RAILWAY BAR CORROSION. 



109 



is greater or less with the same breadth of gauge, dependent upon the po- 
sition of the meeting-points of tlie ends of the rails, which are sometimes 
nearly opposite across the line, but often not so, i. e. the pole of one length 
of rail is opposite nearly to the neutral point of the rail at the other side of 
the railway. 

It is manifest from what precedes, that the polar intensity of any given 
rail in a line of railway depends, not only upon the rolling traffic it is exposed 
to, but also upon the direction of the line of railway itself; that the bars in 
railways running north and south are in a higher state of magnetism, other 
things being the same, than in those running east and west, by the eft'ects of 
terrestrial induction. 

In long lengths of railway, running east and west especially, but in some 
degree in every direction, there are constant thermo-electric currents tra- 
versing the rails from end to end, due to changes in atmospheric temperature, 
between day and night, &c. : such currents have been already noticed by Mr. 
William Barlow as perpetually traversing the wires of the electric telegraph, 
and such currents may occasionally be due to other causes of disturbance of 
the equilibrium of terrestrial electricity than those due to temperature. 

But the passage of locomotive engines over railways is a cause of electric 
currents traversing the bars of a much more important and formidable cha- 
racter. If a galvanometer be placed in connexion with a rail forming part 
of a line of way, and also with the earth at some distance, or with the rails 
at a distant point in advance, powerful deflections are produced by the ap- 
proach of a locomotive engine, or even by the rolling along of a heavy train with- 
out an engine ; in the latter case the effects are comparatively feeble, and appear 
to be due to the repeated compressions and rendings of crystallized surfaces, 
to which the surfaces rolling and rolled on are subjected ; an action shown 
by Becquerel and others, to be an efficient producer of electric disturbance ; 
but in the case of the locomotive engine, a torrent of electric force is let 
loose and finds its way into the earth along the rails, which, from the im- 
perfect contact of their junctions, permit it to pass along the line with diffi- 
culty, and thus the equilibrium is gradually restored in great part through 
the chairs, fastenings and ballast, the resistance being greatest where the line 
is laid on longitudinal sleepers, and these are quite dry. 

There can be little doubt, that if a portion of railway were insulated to- 
lerably from beneath on wood, and a wood block inserted at given points, so 
as to cut ofi" a segment of rails from the line, powerful sparks would flash 
from the rails and train as it passed over this portion of the railway. Indeed 
all this may be inferred from the well-known facts of the hydro-electric 
machine. 

These electrical effects of locomotive engines in motion are somewhat 
uncertain, owing to the saline contents of the water usually employed fre- 
quently interfering ; but after an engine has run a considerable distance 
without stopping, and the passages of efflux steam have become cleaned by 
its continued passage, and the engine does not prime, the evolution of elec- 
tricity Js always considerable. 

As each railway bar may be viewed in the light of a conductor through 
which currents of electricity of variable intensity and quantity are per- 
petually flowing, it is obvious that magnetic currents are also in constant 
circulation round each bar and at right angles to its length : thus if upon 
the bar a, b an engine run over from south to north, the north end of a mag- 
netic needle placed above the rail will be deflected to the left-hand, and vice 
versci. 



110 REPORT— 1849. 

Again, on the other hand, the existence of polarity of variable magnetic 
intensity in every rail involves the existence of electric currents circulating 

Fig. 11. 



round the bars, in accordance with the facts pointed out so well by Dr. Fa- 
raday. And in accordance with the recent experiments of Mr. Grove, the 
constantly recurrent induction of magnetism of great intensity in each rail 
involves a constant change of temperature in the rail, due to this cause alone, 
and probably an equally constant change in the molecular arrangement of 
its particles. 

Such are the facts, so far as I have been enabled to observe them, of the 
complex relations to electricity, magnetism, and terrestrial temperature of 
railway bars ; they fail to throw any direct light upon the immediate subject of 
our inquiry, but since the closest relationship has been proved to subsist be- 
tween all these molecular forces, and especially since the later refined re- 
searches of Faraday and Pliicker have shown that changes in the electrical 
or magnetic state of solids is attended with an instantaneous change in the 
relative groupings of their molecules, and knowing beforehand that chemical 
action in its most ordinary circumstances is powerfully influenced and modi- 
fied by the state of grouping, or of aggregation of these molecules, it seems 
by no means improbable that the chemical action of air and moisture upon 
the iron of railway bars may be more or less modified by the electrical and 
magnetic forces that specially apply to them. To reduce this to certainty, 
demands experiments conducted, not after the manner or with the immediate 
object of those before us, but by refined research in the physico-chemical 
laboratory. 

Interesting as such researches may be to science, and to which the facts 
here recorded may perhaps serve as finger-posts at the commencement of the 
way, they are not of very high value to the practical railway engineer, inas- 
much as we have already found that the destruction of railway bars by cor- 
rosion is small in comparison with that by traffic. Nor are we obliged to 
rest in any vague speculation to find efficient causes sufficient to account 
for the real difference that we have established between the corrosion of the 
same railway bar in use and out of use. 

The three principal causes to which I attribute this difference are, — 

1st. The top surface of a railway bar in use is constantly preserved in a 
state of perfect cleanness, polish, and freedom from oxidation, while the re- 
mainder of the bar is rough, coated originally with black oxide (Ham- 
merschlag) and soon after with red rust (peroxide and basic salts). 

Not only is every metal electro-positive to its own oxides, but, as esta- 
blished in mySecondReporton theAction of Air andWateronIron(sec.242), 
a mass of metal, partially polished and partly rough, is primarily corroded on 
the rough portion. Hence then a railway bar while in use is constantly pre- 
served from rusting by the presence of its polished top-surface. Such polished 
surface has no existence upon the rail out of use. 

2nd. The upper portion of the rail in use is rapidly condensed and hard- 
ened by the rolling of traffic over it ; and I have also shown in the same 
reports, that all other circumstances being the same, the rate of corrosion of 



ON RAILWAY BAR CORROSION. Ill 

any iron depends upon its density, and is less in proportion as this is ren- 
dered greater by mechanical means. 

3rd. As every metal is positive to its own oxides, the adherent coat of rust 
upon iron, while it remains, powerfully promotes the corrosion of the metal 
beneath, and this in a greater degree in proportion as the rust adherent is of 
greater antiquity, inasmuch as it has been shown that the rust produced by air 
and moisture, which at first contains but little peroxide (FcjOg), continues to 
change slowly, and becoming more and more peroxidized, becomes more and 
more electro-negative to its own base. 

Now the rust formed upon a railway bar out of use continues always to 
adhere to it, and thus to promote and accelerate its corrosion, while the rust 
formed upon a railway bar in use is perpetually shaken off by the vibration 
of traffic, and thus this source of increased chemical action is removed. Of 
the extent to which this acts, we are informed by the results of the second 
experiment on the Kingstown Railway, where the weight of adherent rust, 
formed on removal of the bars out of use, was found to be more than four 
times as great as that upon an equal surface of the bars that had been in use. 

We have found that this difference of corrosion in and out of use however 
is a constantly decreasing one ; this arises from the fact that the condensation 
of the top-surface of the rails ceases after it has reached a certain point de- 
pendent on the maximum weight of the trains, and that after the lapse of a 
considerable period a uniform coat of rust is formed upon the rails in use, 
which is so firmly adherent that the vibration and wind of passing trains are 
incapable of sweeping it away ; and it seems possible that after the lapse of 
an extremely prolonged time, the difference between the corrosion of the 
rail in use and out of use might become so small as to be perhaps insensible. 

To recapitulate, then, we have found that railway bars forming part of a 
long line, whether in or out of use, corrode less for equal surfaces than a 
short piece of the same iron similarly exposed ; that the rails in use do cor- 
rode less than those out of use ; that this difference is one decreasing with 
the lapse of time ; that the absolute amount of corrosion is a source of de- 
struction of the rails greatly inferior to that due to traffic; that it is highly 
probable that the electrical and magnetic forces developed in the rails by 
terrestrial induction and by rolling traffic, react in some way upon the che- 
mical forces concerned in their corrosion ; and that therefore the direction of 
lines of railway in azimuth is not wholly indifferent as respects the question 
of durability of rails. 

I am not aware of any information upon this subject having any character 
of accuracy which I can refer to extraneous to the present report. In the 
Franklin Journal, and also in Silliman's Journal, some few papers occur 
giving rather long statements as to the wear of rails on the Lowell and other 
American railways, as also some such in the Mining Journal (London), as 
to some English lines ; as also some observations upon the abrasion of cast- 
iron rails, given by Thompson in his ' Colliery Inventions and Improve- 
ments.' They need not however be extracted here. 

I might also extend this report to a comparison of the relations which 
subsist between the surface per yard lineal exposed to corrosion, and the 
strength and stiffness of the several principal forms of rail in use upon one 
line ; but this can so obviously be done by the engineer for his own purpose, 
that it seems needless. It is however an element of choice in the form of 
rails that appears heretofore to have been wholly neglected. 

I conclude therefore with two practical suggestions, deducible from the 
information we have obtained, having for object the increasing the durability 
of rails, both as against traffic and corrosion. First. Of whatever quality of 



112 REPORT — 1849. 

iron rails are rolled, I would suggest that they should be subjected prior to 
use to an uniform course of hammer hardening all over the top-surface and 
sides of top flange of the rail. The effect of this would be two-fold ; the rail 
will be stiffened witiioutany material reduction in ultimate strength ; its sur- 
face will be hardened and polished, and hence best calculated to resist cori'o- 
sion and abrasion ; and lastly, the direction of the principal axes of the crystals 
of the iron, or of its "fibre," will for a small depth be changed and brought 
perpendicular to the surface of the rail, by which the tendency to lamination 
by rolling traffic will be greatly reduced. It will occur to any practical 
engineer that machinery may be constructed with perfect facility by which 
this hammer-hardening may be performed with rapidity and perfect smooth- 
ness and uniformity, the bar being slowly advanced, end on, under small 
hammers with suitably formed faces, driven rapidly by power. The total cost 
of the operation would amount to but a trifle on a ton of rails. 

Secondly. I would suggest that all railway bars, before being laid down, should, 
after having been gauged and straightened, &c., be heated to about 400° Fahr. 
(but not higher, for fear of injuring the effect of the hammer-hardening), 
and then coated with boiled coal-tar; this I have proved in the preceding 
experiments to last for more than four years as a coating perfectly impervious 
to corrosive action while constantly exposed to traffic. The outlay for this 
would be very small; and if its value were no more than that after the lapse 
of eight or more years, when a set of rails had to be replaced in consequence 
of wear, the whole of the iron, which would have otherwise been dissipated 
in rust, would be returned to the furnace to be remade, the outlay would 
be well""bestowed. 

I would respectfully commend these suggestions to my professional brethren 
as worthy of trial, and have now fulfilled, so far as I have been able, the 
commands of the British Association, as to the corrosion and wear of rails. 



ON ELECTRICAL. OBSERVATIONS AT KEW. 113 



Report on the Discussion of the Electrical Observations at Kew. 
By William Radcliff Birt. 

The electrical observations made at the Observatory of the British Associa- 
tion at Kew from August 1, 1843, to August 8, 1848, are divisible into two 
portions, one occupying a period of seventeen months, viz. from August 1843 
to December 1844 both inclusive, during which the readings were taken at 
sunrise, 9 a.m., 3 p.m. and sunset ; the other, a period of three years and 
seven months, viz. from January 1844 to July 1848, also inclusive, during 
which the readings were taken at each even hour of Greenwich mean time 
as well as at sunrise and sunset. The last portion, which is by far the most 
complete, furnishes, from the observations of three complete years, the materials 
for deducing the diurnal and annual periods of the electrical tension. This 
has accordingly claimed our first attention and forms the first section ot 
Part I., which is exclusively devoted to the examination of Positive Electricity. 

The observations at sunrise and sunset, extending over the entire period 
of the five years, from the variability of the epoch of observation, require a 
separate discussion ; they accordingly form the subject of the second section ; 
and the third section is occupied with a discussion of the observations during 
the first seventeen months. 

Scattered over the entire period of the five years we have several readings 
of negative electricity, and as they are evidently accompanied by meteorolo- 
gical phsenomena of a peculiar and unmistakeable character which strongly 
indicate them to be the results of disturbances, rather than their forming any 
portion of a regular progression of the electric signs, they have also been 
separately discussed. Their discussion forms Part II. of this Report. 

Part I.— POSITIVE ELECTRICITY. 

Section I.— Discussion of Positive Readings during the Years 1845, 1846 

and 1847. 
Durin'^the years 1845, 1846 and 1847, 10,526 observations were recorded 
in the Journal", including the indications of the night-registenng apparatus. 
Of these — 

10,176 were positive ; 
324 „ negative, and 
26 „ not employed in the discussion ; 

10,326 

In the following table are recorded the twenty-six unemployed readings 
which were positive; they were in almost every case either preceded or suc- 
ceedc»l by negative readings, from which it was concluded that they resulted 
more from a disturbance in the usual electrical condition of the atmosphere, 
than that they formed a part of its regular diurnal march : from these cir- 
cumstances, connected with the high tensions mostly exhibited, it was appre- 
hended the results would have been materially affected by employing them 
in the investigation. 

In the following discussion, readings occasionally higher than some ot those 
recorded below have been employed, but they have evidently formed either 

1849. ^ 



114 REPORT — 1849. 

a part of a regular diurnal movement, or have occurred at such hours as are 
generally distinguished bj- exhibiting an increase of tension. It was con- 
sequently considered that a rejection of them would to a certain extent in- 
terfere with the development of the diurnal and annual curves. The values 
in the table, as well as throughout the discussion, are recorded in terms of 
Volta's electrometer No. 1. The observations were taken with Henley's in- 
strument, 1 degree of which has been approximately considered to be equal 
to 100 divisions of Volta No. 1 *. 

* On the 13th and 14th of July 1849, the reporter attended at the observatory for the 
purpose of comparing the electrometers, and especially determining the value of the readings 
of Henley's electrometer in terms of Volta's standard No. 1. The following are the results of 
the comparison. It appears from upwards of two hundred readings, the charge varying be- 
tween 50 div. and 110 div. of Volta No. 1 as read from the scale of the No. 2 electrometer, 
that the mode of reading adopted by the observer at Kew, during the five years, was to bring 
the eye into such a position that the inner edge of the straw should coincide with the division 
read on the ivory arc of the instrument. By this mode of reading, 1° of Henley would very 
nearly equal in value 100 div. of Volta ; this value has accordingly been retained, as most in 
accordance with the mode of reading adopted. It will be however evident that the true read- 
ing would be given, not by either edge of the straw, but by the centre: the diameter of the 
straw is equal to 2°; consequently when the inner edge coincides with 1°, the true reading must 
be 2°. From this it is clear that the values in the following discussion are relatively too high, 
but they will not interfere with the results further than by expanding the curves ; the inflexions, 
points of maxima and minima, and the general form of the curves, will be the same, conse- 
quently the results derived from these curves will be unaffected. It would have been desirable 
to have applied a correction for this dift'erence in the mode of reading, had not a greater dif- 
ficulty presented itself in the dissimilarity of the construction of the two instruments, by which 
the values at diff'erent parts of the scale of Henley's instrument acquire different values in terms 
of Volta's instrument. The small extent of range common to both instruments renders it very 
difficult to express the higlier readings of Henley at all accurately in terms of Volta. It is 
therefore consideied best under the circumstances to retain the values as given in the tables, 
especially as the results are not materially interfered with ; and endeavour to point out a mode 
by which the readings of Henley's instrument may be accurately expressed in terms of Volta, 
as well as to indicate a more precise method of observation. 

The standard electrometer No. 1 of Volta is so constructed that a given electric force causes 
a pair of straws of a known weight to diverge. Their divergence is measured on a circular arc 
of the same radius as the length of the straws, which is so graduated as to indicate half the 
distance in arc between the extremities of the straws in half- Parisian lines, each of the divi- 
sions, which are at equal distances from each other, being equal to half a line. It is clear from 
this construction of instrument, that upon measuring the distance between the straws in a 
right line, the sine of half the angle subtended by the extremities of the straws is proportional 
to the electric tension of the charge. 

The electrometer No. 2 is so constructed that each division is exactly equal to five of No. I, 
and the circular arc is graduated to read at once the electric tension in terms of No. 1. The 
difference in the electrometers consists in the straws of No. 2 being heavier than those of No. 1, 
in such a proportion as to increase the value of the readings in the ratio above mentioned. As in 
No. 1 the sine of half the angle of divergence is proportional to the tension, so in No. 2 precisely 
the same value of the tension obtains, viz. the sine of half the angle of divergence, the linear 
value of the sine itself being proportional to its value in No. 1 for the same force : thus, a force 
that would diverge the straws in No. 1 to an angle of 30° would only open them in No. 2 to an 
angle of 6 , and in each instrument the sines of 15° and 3° respectively would represent the 
same force. There is however no necessity to employ such a determination of the force, the 
graduation of each instrument being amply sufficient for the purpose. 

The Henley's electrometer is so constructed that the force is measured by a straw termi- 
nating in a pith-ball, which together constitute a pendulum that is inserted in a ball working 
by two fine steel pivots. This pendulum diverges by the electric force from the perpendicular, 
the angular amount of divergence being measured by a quadrant, graduated to degrees of the 
circle on an ivory scale. As it is thus used, the readings are not very readily comparable with 
those of the Volta's electrometers, in consequence of the Henley readings being in arc, while 
those of Volta are in linear measure. This difficulty may however be readily overcome by 
immediately measuring the sine of the angle of divergence, which in this instrument is a 
measure of the electric tension. Nothing further would be required than to place the elec- 
trometer in a convenient position for observation by a theodolite, which should be firmly fixed 
at a known distance from it. The centre of the azimuth circle should be in the precise verti* 



ON ELECTRICAL OBSERVATIONS AT KEVV. 



115 



]. 



cal plane of the centre of the pith-ball when nnelectiified, and should be at such a distance 
that the arc measured by it may be of sufficient range to determine 
the length of the sine with tolerable accuracy. The distance between 
the centres of the azimuth circle and pith-ball should, if possible, be 
of such a value in half- Parisian lines as to facilitate tlie formation of a 
table for obtaining the value of the sine in half-Parisian lines by in- 
spection, so that a simple observation of the bisection of the right and 
left limbs of the pith-ball, which of course would be in arc, and the 
deduced divergence in arc of its centre from iis plane of rest when 
unelectrified, would, with the assistance of the table, give at once the 
electric tension in half- Parisian lines; and these readings might readily 
be converted into terms of Volta's electrometer No. 1, by properly 
adjusting the straw, pith-ball, &c. to a definite value, so that a diver- 
gence of lialf a Parisian line may be equivalent to a certain number of 
divisions of Volta's standard electrometer. In this way, it is clear, the 
tensions might be expressed in terms of Volta's standard up to 90° 
of Henley without the necessity of applying corrections, unless such 
corrections should be rendered necessary from the effects of gravity on 
the pendulum. 

The whole matter may be rendered plain by the annexed diagram 
(fig. 1). Let A represent the centre of the pith-ball when unelectrified, 
and B the centre of the azimuth circle of the theodolite. The di- 
stance B A will form the base of a i-ight-angled triangle, of which the 
divergence of the pendulum P— A' is the perpendicular. When the 
instrument is electrified, the pith-ball diverges in a plane at right 
angles to the plane passing through its centre when unelectrified, 
and that of the azimuth circle ; or in other words, the plane of its 
motion passes vertically through the line A C, and is at right angles 
to the vertical plane passing through the line A B. If now the 
theodolite is so adjusted that the limbs of the pith-ball may be 
bisected, the azimuth circle will measure in arc the sine of the angle 
of divergence, and thus we have given the side and angles of a right- 
** angled triangle from which the linear measure of the divergence may 

readily be deduced. The analogy is as follows: — Radius is to the tangent of the horizontal 

angle, as the distance between the centres of the pith-ball and azimuth circle is to the 

divergence. 

Suppose the distance A B = 500 half-lines ; 

The azimuthal angle = 6°; 

Then Log AB = 2-C98970 

„ Log tan 6° = 9-021620 



„ Log52-55-H = 1-720590 

Consequently the divergence is equal to 52-55 half-Parisian lines in a plane at right angles to 
the vertical plane passing through the above-mentioned centres. 

N.B. The diagram is constructed in accordance with the above example. 

It is not absolutely necessary to employ a theodolite. A telescope furnished with cross vfires 
firmly fixed on a support having its centre of azimuthal motion at a known constant and in- 
variable distance from the centre of the pith-ball when unelectrified, the angle being measured 
by an arm sufficiently extended to include the angle subtended by the pendulum when de- 
flected from the perpendicular 90°, will be sufficient. A vertical motion should be given to the 
telescope by rackwork by which it can be raised to the level of the pith-ball when electrified, 
and it should be furnished with a level, Sec. to ensure horizontality. 

The above remarks have reference to the expression of the electric tension in the linear 
terms adopted by Volta, viz. half-Paris lines, and are principally applicable to the retention 
of Volta's notation so far as the measurement of the sine of the angle of divergence from the per- 
pendicular is concerned ; but Mr. Ronalds has suggested a much better mode of connecting the 
readings of the two instruments, viz. a conversion of the readings of Volta's electrometer (half 
Paris lines) into measures of arc, so that the readings of the three instruments, Volta No. 1, 
Volta No. 2, and Henley, and even of the discharger, may all be expressed in degrees of the 
circle, the sines of which are of course readily ascertainable. 



I 2 



116 



REPORT 1849. 



Table I. 
Unemployed positive readings. 



Date. 


Div 

VoltaNo. 1. 


Date. 


Div. 
VoltaNo. 1. 


1845. Feb. 23, 


8 a.m. 


2000 


1846. June 25, 2 p.m. 


4500 


1845. May 20, 


8 p.m. 


3000 


1846. Aug. 1, 4 p.m. 


5500 


1845. May 26, 


noon. 


4500 


1846. Aug. 1, 6 p.m. 


5500 


1845. June 4, 


2 p.m. 


3500 


1846. Aug. 3, noon. 


1500 


1845. July 11, 


2 p.m. 


2000 


1846. Aug. 5, 6 a.m. 


3000 


1845. Aug. 7, 


2 p.m. 


1000 


1847. Mar. 10, 4 p.m. 


2500 


1845. Aug. 7, 


4 p.m. 


2000 


1847. Apr. 29, 4 p.m. 


2500 


1846. Feb. 27, 


noon. 


2000 


1847. Apr. 29, 6 p.m. 


1000 


1846. Mar. 26, 


6 p.m. 


4500 


1847. Apr. 30, 2 p.m. 


2500 


1846. Apr. 25, 


2 p.m. 


3000 


1 847. May 3, 2 p.m. 


3000 


1846. Apr. 26, 


6 a.m. 


2000 


1847. July 17, 6 a.m. 


2000 


1846. May 6, 


2 p.m. 


4500 


1847. July 17, 8 a.m. 


3500 


1846. May 20, 


2 p.m. 


5000 


1847. Dec. 30, noon. 


3000 



Diurnal Period. 

Diurnal period. Year. — In examining the results obtained from a dis- 
cussion of the positive observations, it will be desirable to confine our atten- 
tion first to the diurnal period of the electrical tension, or to those variations 
exhibited by the electrometers which have a day for the period in which they 
are completed, and which evidently depend on, or are connected with, the 
rotation of the earth on its axis. 

The 10,176 observations upon which the mean diurnal period of the three 
years is based, are thus distributed among the twelve daily readings. 

Table II. 

Number of positive readings at each observation-hour in the three years 

1845, 1846 and 1847. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 8 a.m. 


10 a.m. Noon. 2 p.m. 


4 p.m. 


6 p.m. '8 p.m. 


10 p.m. Sums. 

^ 1 


1845. 
1846. 
1847. 


222 
234 
199 


236 
257 
255 


246 
269 
289 


190 
190 
186 


341 
353 
353 


327 
338 
348 


275 

288 
285 


297 
278 
283 


302 
287 
289 


301 

281 
289 


302 
286 
290 


332 
338 
337 


3374 
3399 
3403 


Sums. 


655 


748 


804 


566 


1047 


1013 848 


858 


878 


874 


878 


1007 1 10176 



It will be remarked, that the greatest number of positive observations 
were recorded at 8 a.m., and the least number at 6 a.m. The numbers from 
noon to 8 p.m. do not vary materially in amount; but at 10 p.m. the number 
again increases. By consulting the following table of the distribution of 
negative observations, it will be seen that the greatest number occurred be- 
tween 8 a.m. and 8 p.m. exclusive; this will to some little extent account for 
the difference ; but the principal cause is, that on Sundays the observations 
were suspended between 10 a.m. and 10 p.m. exclusive. The small number 
of observations at 6 a.m. arises from the fact, that during the winter months, 
the personal observations were not commenced until 8 a.m., or more pro- 
perly speaking until sunrise. 



ON ELECTRICAI* OBSERVATIONS AT KEW. 
Table III. 



117 



Number of negative readings at each observation-hour in the three years 
1845, 1846 and 1847. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums, 


1845. 
1846. 

1847. 


3 

1 
3 


5 

4 

1 


5 
4 
1 


5 
5 

4 


11 
9 
9 


17 

18 
11 


13 
11 
10 


16 
11 
13 


22 
12 

7 


20 

10 

9 


17 
5 
5 


15 

4 
8 


149 
94 
81 


Sums. 


7 


10 


10 


14 


29 


46 


34 


40 


41 


39 27 


27 


324 



The mode of discussion adopted has been, to arrange all the positive 
readings under the respective hours of observation, and then to divide their 
sums by the number of readings at each hour, so tlaat the values recorded in 
the following tables are the arithmetical means of the readings at each ob- 
servation-hour. The transcription from the Journal has been most carefully 
checked, and eveiy precaution taken to ensure accuracy, both in ascertain- 
ing the number of observations and in calculating the means ; in the latter 
case the arithmetical operations have been executed in duplicate. The re- 
sults of these computations, as before mentioned, are expressed in terms of 
Volta's standard electrometer No. 1, all observations of tensions exceeding 
the range of this instrument having been reduced to its readings (see de- 
scription of electrometers, ' Report,' 1844, p. 124, and the previous note on 
p. 1 14 of this Report). 

On the 1st of January 1845, when the night-registering apparatus was 
first brought into use, a note occurs in the register which it is important to 
transcribe here. It is as follows : — 

" The electric tensions at the hours 0, 2 and 4 are estimated by adding a 
quarter of a degree (of Volta) to the tensions exhibited by the three night- 
registering electrometers at sunriiie, for each hour lohich has elapsed between 
the time at which they toere charged {by the clocK) and the time of observing 
them {viz. sunrise). 

" The rate of loss by these electrometers begins to be inconstant after the 
tension has exceeded about 50° (of Volta): vide Experiments, 1844, p. ; 
if, therefore, the tension at sunrise of any such instrument shall exceed 50°, 
it is not noted in the Journal*." 

Table IV. 

Mean electrical tension at each observation-hour in the three years 1845, 
1846 and 1847, with the mean diurnal period as deduced from the whole. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 
19-8 
24-3 
23-7 


div. 

17-8 
21-2 
21-1 


div. 
18-3 
21-4 
21-5 


div. 
28-6 
35-4 
38-7 


div. 
64-7 
611 
78-7 


' div. 
84-4 
76-7 

102-5 


div. 

67-9 
69-6 

88-4 


div. 
59-9 
65-5 
89-4 


div. 
59-2 
63-5 
85-0 


div. 

711 
85-0 
991 


div. 
98-9 
96-3 
112-0 


div. 
117-2 

87-2 
107-9 


div. 
63-1 
61-3 
76-3 


Mean. 


22-6 


201 


20-5 


34-2 


68-2 


88-1 


75-4 


71-5 


69-1 


84-8 


102-4 


104-0 


66-9 



* For a full description of tliese night-registering electrometers, see 'Report,' 1844, p. 13S, 
under the head of " Experiments on insulation by means of chloride of calcium." 



118 



REPORT — 1849. 



Table V. 

Excess or defect of the mean electrical tension at each observation-hour, as 
compared with the mean of the year, for the three years 1845, 1846 and 
184-7, and the mean diurnal period. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4p,m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 

43-3 
370 
52-6 


di^. 
45-3 
401 
55-2 


div. 
44-8 
39-9 
54-8 


div. 

34-5 
25-9 
37-6 


div. 
+ 
1-6 

0-2 

+ 
2-4 


div. 

+ 

21-3 

+ 
15-4 

+ 
26-2 


div. 
+ 
4-8 
+ 
8-3 
+ 

121 


div. 

3-2 

+ 
4-2 

+ 
13-1 


div. 

3-9 

+ 
2-2 

4- 
8-7 


div. 
+ 
8-0 
+ 

23-7 
+ 

22-8 


div. 

+ 

35-8 

+ 
350 

+ 
35-7 


div. 

+ 
541 

+ 
25-9 

+ 
31-6 


div. 

631 
61-3 
76-3 


Mean. 


44-3 


46-8 


46-4 


32-7 


+ 
1-3 


+ 
21-2 


+ 
8-5 


+ 
4-6 


+ 
2-2 


+ 
17-9 


+ 
35-5 


+ 
37-1 


66-9 



The above tables, which are based upon the numbers in Table II., clearly 
exhibit a double progression of the electrical tension during the twenty-four 
hours. The means of the first two years closely approximate, and in connexion 
with the general course of the numbers, give a proportional confidence, both 
with regard to the care manifested in making the observations and the faith- 
fulness of the record. The third year exhibits upon the whole a higher ten- 
sion, the means at midnight and 2 a.m. being the only values that are lower 
than those of the same hours in 1846. The mean of all the observations is 
66*9 divisions of Volta's electrometer No. ] . 

There are only three exceptions to the general fact, that from 8 a.m. to 10 
P.M. the mean electrical tension is above the mean of the year. The mean 
diurnal period, as deduced from the three years, does not exhibit any depres- 
sion below the mean of all the observations between the above-mentioned 
hours. The hours that exhibit a depression below the mean are midnight, 
2, 4 and 6 a.m., and these are considerably in defect. The hour of mini- 
mum tension appears to be 2 a.m., a gradual rise taking place from that hour 
until 6 A.M. Between the hours of 6 and 8 a.m. a rapid rise occurs, the 
tension being nearly doubled ; it then increases gradually until 10 a.m., when 
a maximum is passed, after which it gradually declines until 4 p.m., the epoch 
of the diurnal minimum as contradistinguished from the nocturnal minimum. 
The tension then rapidly increases until 8 p.m., and at 10 p.m. passes another 
maximum rather considerably above the maximum of 10 a.m. From 10 p.m 
to midnight (two hours) the diminution of the tension is enormous, 81*4 
divisions of Volta No. 1. The midnight value is but slightly above the 
value at 2 a.m., the epoch of the minimum. 

The diurnal march of the tension is rendered more apparent to the eye by 
the annexed curves (fig. 2). The general similarity of the movements in the 
three years, and the close agreement between the curves of these years, and 
that of the mean diurnal curve as deduced from them, is, to a certain extent, 
satisfactory. The forenoon maximum is well marked in each case, as well 
as the evening maximum: in 1846 and 1847 this occurred at 8 p.m., and it 
may be probable that 9 p.m. may be the hour at which it is most frequently 
exhibited. 

The lower readings at midnight, 2, 4 and 6 a.m., demand particular atten- 
tion. From the note above extracted (see page 117), we find that tensions at 
these hours, above 50 div. of Volta No. 1, do not enter into the discussion. 
It is not only highly probable, but the absence of records at these hours, when 
Henley's electrometer has ranged rather high, indicates that the conductor 



ON ELECTRICAL OBSERVATIONS AT KEW. 



119 



4 A.M. 10 A.M. 



Mean. £ 






has possessed much higher charges than 50 div. at the hours of 0, 2 and 4. 
j4 ^ The inference undoubtedly is, that 

S S m the means at those hours are too low, 

and as a consequence, the mean of 
each year, as well as the mean of all 
the observations, is also too low. With 
regard to the hour of 6 a.m., the 
value appertains only to the summer, 
very few observations occurring at 
this hour in the winter. When we 
come to discuss the seasons, it will be 
seen that the higher tensions inva- 
riably occur in the winter; the value 
at 6 A.M., upon the whole year, is 
therefore also too low ; consequently, 
were we in possession of either an un- 
interrupted series of joersowa^ observa- 
tions duringthe day and night, or care- 
fully executed photographic registers 
for the same period, we should doubt- 
less have a curve which would exhibit 
neither so rapid a rise from 6 a.m. to 
8 A.M., nor so great a fall from 10 
P.M. to midnight, but M^ould at these 
hours be more in accordance with its 
other portions. Of course it is im- 
portant, in reference to this point, to 
bear in mind the circumstances under 
which the observations were made, 
the personal establishment not having 
enabled the observer to continue the 
observations during the night, and the 
uncertain diminution of the charges 
of the night-registering electrometers! 
above 50 div. rendering it preferable 
not to record the indications of the 
instruments above 50 div., rather than 
S S insert numbers likely to vary from 

the truth, and for which there are no certain means of correction. From a 
consideration of the tables and curves, it will be apparent, that the hour most 
suitable for observing the mean electrical tension during the entire year is 
8 A.M., the difference from the mean at this hour being 1*3 div. in excess. 

Diurnal period. Summer. — The 10,176 observations from which the 
diurnal period having reference to the entire year has been deduced, are 
thus divided: — 

Summer 5,514 

Winter 4,662 



3 years. 




4 A.M. 10 A.M. 



lOP.M. 2A.M. 



10,176 
The following table exhibits the distribution of the summer observations 
among the twelve daily readings : the months considered to constitute the 
summer half-year are, April, May, June, July, August and September : — 



120 



REPORT — 1849. 



Table VI. 

Number of positive readings at each observation-hour in the three summers 
of 1 845, 1846 and IS*?. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 


1845. 
1846. 
1847. 


135 
140 
125 


135 
149 
148 


147 
155 
163 


176 
172 

177 


174 
175 
178 


167 
170 
173 


135 
142 
139 


146 
135 
137 


149 
139 
141 


152 
138 
140 


158 
148 
147 


171 
169 
169 


1845 
1832 
1837 


Sums. 


400 


432 


465 525 


527 


510 


416 


418 


429 


430 


453 


509 


5514 



These numbers are more neai'ly equal in their amount than the yearly 
distribution. 

Table VII. 

Mean electrical tension at each observation-hour in the three summers of 
1845, 1846 and 1847, with the mean diurnal period of summer. 



Year. 

1845. 
1846. 
1847. 


Mid. 


2 a.m. 


4 a.m. 6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


div. 

19-6 
21-0 
23-5 


div. 

16-0 
17-4 
200 


div. 

17-3 
19-4 
19-8 


div. 

29-1 
33-9 
36-7 


div. 
39-4 
44-9 
46-5 


div. 

34-8 
47-1 
57-9 


div. 

29-6 
34-9 
35-4 


div. 
33-8 
33-9 
37-8 


div. 

32-6 
36-3 
37-0 


div. 
36-6 
40-4 
39-8 


div. 

53-6 
49-1 
49-7 


div. 

71-1 
55-0 
64-2 


div. 
35-3 
36-5 
39-7 


Mean. 


21-3 


17-8 


18-9 


33-2 


43-6 


46-7 


33-4 35-1 


35-2 


38-9 


50-8 


63-4 


37-2 



Table VIII. 
Excess or defect of the mean electrical tension at each observation-hour as 
compared with the mean of each summer in the years 1845, 1846 and 
1847, and the mean of the three summers. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


1845. 


15-7 


19-3 


18-0 


6-2 


+ 
4-1 


0-5 


5-7 


1-5 


2-7 


+ 
1-3 


+ 
18-3 


+ 
35-8 


35-3 


1846. 


15-5 


19-1 


17-1 


2-6 


+ 
8-4 


+ 
10-6 


1-6 


2-6 


0-2 


+ 
3-9 


+ 
12-6 


+ 
18-5 


36-5 


1847. 


16-2 


19-7 


19-9 


30 


+ 
6-8 


+ 
18-2 


4-3 


1-9 


2-7 


+ 
01 


+ 
10-0 


+ 
24-5 


39-7 


Mean. 


15-9 


19-4 


18-3 


4-0 


+ 
6-4 


+ 
9-5 


3-8 


2-1 


2-0 


+ 
1-7 


+ 
13-6 


+ 
26-2 


37-2 



In contrasting the numbers in Tables VII. and VIII. with those in Tables 
IV. and V. liaving reference to the entire year, we are struck with the greater 
uniformity that prevails among those appertaining to the summer. Tlie 
means approximate more closely to each other, the general course of the 
numbers is more regular, and the rise during the morning hours more gentle, 
although there is still a considerable diminution of tension between 10 r.ai. 
and midnight. 

In contemplating the numbers in Table VIII., indicating the excess or de- 
fect in comparison with the mean, we see af a glance that the double pro- 
gression is well exhibited : at noon, 2 and 4 p.m., the numbers are in defect, or 
lower than the mean, as well as at midnight, 2, 4 and 6 a.m. It may be 
proper to mention here, that during the summer months the tension seldom 



ON ELECTRICAL OBSERVATIONS AT KEW. 



121 



rises above 100 div. of Volta No. 1, except at particular hours ; this will 
form a subject of discussion further on ; in the meantime it enables us to 
gain some insight into the reason of the diurnal period during the summer 
months in each year being more in accordance with itself than that of the 
entire year. The defect of the early morning hours is not so great as the 
excess at 10 p.m.; consequently the mean line cuts the entire curve more 
equably, exhibiting the two maxima above, and the two minima below it. 
This doubtless arises from the very few tensions above 50 div. that occur 
during the summer nights, as well as from the observations at 6 a.m., which 
are generally low. We have therefore a period that differs but little, if any, 
from the natural progression of the electrical tension : 2 a.m. is the epoch of 
the principal minimum; the tension gradually rises from this hour until 10a.m., 
the forenoon maximum ; the succeeding minimum occurs at noon, the de- 
cline in the two hours being 13*3 div. ; the rise is then very slow and gradual 
until 4 p.m., only 1*8 div. ; at 6 p.m. the tension increases and mounts rapidly 
until 10 P.M., the principal maximum; the decline is then very considerable 
from 10 P.M. to midnight. 

Table IX. 

Comparison of the excess or defect from the mean of the diurnal periods de- 
duced from all the observations, and from those made during the summer 
months. 



Season. 


Mid. 


2 a.m. 


4 am. 


6 a.m. 


8a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 




— 


— 


— 


— 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 




Year . . 


44-3 


46-8 


46-4 


32-7 


1-3 


21-2 


8-5 


4-6 


2-2 


17-9 


35-5 


37-1 


66-9 




— 


— 


— 


_ 


+ 


+ 


— 


— 


— 


+ 


+ 


+ 




Summer. 


15-9 


19-4 


18-3 


4-0 


6-4 


9-5 


3-8 


21 


20 


1-7 


13-6 


26-2 


37-2 



The above table places the diurnal period of the summer months in con- 
trast with that of the entire year. 

The annexed curves (fig. 3) exhibit the diurnal march of the tension 
during the summer months. The same similarity of movement is noticed as in 
the yearly curves ; it is however worthy of remark, that the depression in or 
about the afternoon does not differ very essentially from that of the entire 
year, with the exception of the minimum occurring at noon. During the 
summer the evening maximum is 16'7 div. above the forenoon maximum, 
and during the entire year it is 15*9 div. The afternoon minimum is de- 
pressed below the evening maximum during the year 34'9 div., during the 
summer it is 30'0 div. Tliis is in decided contrast with the lower branches 
of the curves, which exhibit a much greater difference. The difference of 
range in the two series of curves has not been exhibited, from the considera- 
tion that the nocturnal minimum of the entire year is probably too low. 

Diurnal period. Winter. — The months constituting the winter half-year 
are, October, November, December, January, February and March. In the 
tables that follow, the means are not of consecutive months, but of January, 
February and March at the commencement, and October, November and 
December at the end of each year. 



122 



REPORT 1849. 



Fig. 3. 



Fig. i. 



3 summers 




Table X. 

Number of positive readings at each observation-hour in the three winters of 
1845, 184-6 and 1847. 



Year. 


Mid. 2 a.m. 


4a.iii. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 


1843. 
1846. 
1847. 


8/! 101 
94 108 
74 j 107 


99 
114 
126 


14 

18 

9 


167 
178 
175 


160 
168 
175 


140 
146 
146 


151 
143 
146 


153 
148 
148 


152 
143 
149 


144 
138 
143 


161 
169 
168 


1529 
1567 
1566 


Sums. 255 , 316 


339 


41 


520 


503 


432 


440 


449 


444 


425 


498 


4662 



ON ELECTRICAL OBSERVATIONS AT KEW. 



Table XI. 



123 



Mean electrical tension at each observation-hour in the three winters of 1845, 
IS^e and 1847j with the mean diurnal period of winter. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6p.m.:8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 
20-1 
29-2 
23-9 


div. 
20-2 
26-5 
22-7 


div. 
19-8 
24-2 
23-6 


div. 
23-5 
49-2 
76-9 


div. 

90-9 

77-0 

111-4 


div. 

136-3 
106-7 
146-6 


div. 

104-8 
103-3 
138-9 


div. 

85-2 

95-4 

137-9 


div. 
85-2 
89-2 
130-7 


div. 
105-6 
128-1 
154-8 


div. 

148-6 
146-9 
176-1 


div. 

166-3 
119-4 
151-9 


div. 

96-7 

90-4 

119-1 


Mean. 24-5 


23-2 


22-7 


46-5 


93-1 


130-0 


115-8 


106-0 


101-5 


129-4 


157-3 


145-5 


102-1 



Table XII. 

Excess or defect of the mean electrical tension at each observation-hour as 
compared with the mean of each winter in the years 1845, 1846 and 1847, 
and the mean of the three winters. 



Year. 

1845. 
1846. 
1847. 


Mid. 


2 a.m.'4 a.ra. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean.l 


div. 

76-6 
61-2 
95-2 


div. 
76-5 
63-9 
96-4 


div. 

76-9 
66-2 
95-5 


div. 

73-2 
41-2 
42-2 


div. 

5-8 

13-4 

7-7 


div. 

+ 

39-6 

+ 
16-3 

+ 
27-5 


div. 
+ 
8-1 

■f 
12-9 

4- 

19-8 


div. 

11-5 

+ 
5-0 

+ 
18-8 


div. 
11-5 

1-2 

+ 
11-6 


div. 
+ 
8-9 
+ 

37-7 
+ 

35-7 


div. 

+ 

51-9 

+ 
56-5 

+ 
570 


div. 

+ 

69-6 

+ 
29-0 

+ 
32-8 


div. 

96-7 

90-4 

119-1 


Mean. 


77-6 


78-9 


79-4 


55-6 


9-0 


+ 
27-9 


+ 
13-7 


+ 
3-9 


0-6 


+ 
27-3 


+ 
55-2 


+ 
43-4 


102-1 



Most of the remarks offered under the head of " Diurnal period, Year," will 
equally apply to the present tables. There is, however, one feature that is 
very striking, viz. the greater range as well as amount of tension during the 
winter months, and that independent of the low readings during the early 
morning hours. The double progression is even more decided than in either 
of the former cases. In tracing the diurnal march we find the minimum at 
4 A.M., a comparatively gentle rise takes place at 6 a.m., after which the 
tension rapidly mounts until 10 a.m., the forenoon maximum ; it then gra- 
dually declines until 4 p.m., the afternoon minimum, and from this hour the 
rise is very rapid until 8 p.m., the epoch of the evening maximum. A fall of 
11*8 div. takes place between 8 and 10 p.m., and then the enormous fall 
occurs between 10 p.m. and midnight, which we noticed in the yearly curves. 
The elevation of the evening above the forenoon m.aximum equals 27*."3 div., 
and the depression of the intermediate minimum is as great as 55*8 div. 
The recess of the nocturnal maxima and minima from each other is interest- 
ing. The above phaenomena are very clearly apparent in the annexed curves 
(fig. 4). 

On contrasting these curves with those of the summer half-year (fig. 3), 
and comparing both with the curves having reference to the entire year 
on p. 119, the influence of the wiuter curves on those of the year is readily 
seen : the yearly curves present precisely the same general features as the 
winter curves. Taking this circumstance in connexion with the greater 
number of higher readings in winter than in summer, it may be inferred that 
the higher tensions materially influence the general results. The influence 



124 



REPORT — 1849. 



of season in both instances, viz. the difference of tension and the form of 
curve, is very apparent from the series of summer and winter curves. 

Table XIII. 

Comparison of the excess or defect from the mean of the diurnal periods 
deduced from the observations in summer and winter. 



Season. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


S a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


Summer. 


1.59 


19-4 


18-3 


4-0 


+ 

6-4 


+ 

9-5 


3-8 


2-1 


2-0 


+ 
1-7 


+ 
13-6 


+ 
26-2 


37-2 


Winter. 


77-6 


78-9 


79-4 


55-6 


9-0 


+ 
27-9 


+ 
13-7 


+ 
3-9 


0-6 


+ 
27-3 


+ 
55-2 


+ 
43-4 


102-1 



In the above table the summer and winter diurnal periods are placed in 
contrast. 

Table XIV. 
Synopsis of the principal points in the summer, winter, and yearly curves. 



Season. 


Nocturnal 
Miuimura. 


Forenoon 
Maximum. 


Afternoon 
Minimum. 


Evening 
.Maximum. 


Even. Max. 

above 
Forenoon. 


Aftern.Min. 

below 
Even. Max. 


Summer. 
Winter .. 
Year ... 


2 a.m. 
4 a.m. 
2 a.m. 


10 a.m. 
10 a.m. 
10 a.m. 


Noon. 
4 p.m. 
4 p.m. 


10 p.m. 

8 p.m. 

10 p.m. 


div. 

lG-7 
27-3 
15-9 


div. 

300 
55-8 
34-9 



The numbers in the last two columns clearly indicate a greater diurnal 
range of tension in winter than in summer; and this is very apparent from 
the curves, the upper portions of those of the winter being much bolder, and 
the depressions more distinctly marked, than the similar features of the sum- 
mer curves. It is to be remarked, that although the diminution of tension 
between 10 p.m. and midnight is not so great in summer as in winter, the 
precipitate downward movement of the curve, which is so strikingly apparent 
in winter, does not in the summer disappear altogether, so as to give the 
curve that gentle depression to the nocturnal minimum which characterizes 
the rise from the afternoon minimum. 

The three following tables exhibit the mean electrical tension at each ob- 
servation-hour for each month in the years 1845, 1846 and 1847, with the 
monthly, seasonal, and yearly means. The characters of the monthly move- 
ments are exhibited to the eye in the sheets of curves illustrating this report. — 
See Plates VI. VII. and VIII. 



ON ELKCTBICAL OBSERVATIONS AT KEW. 



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ON ELECTRICAL OBSERVATIONS AT KEW. 12/ 

Table XVTII. exhibits the mean monthly electrical tension at each ob- 
servation-hour deduced from the observations of three months, also the 
mean summer, winter, and yearly tensions deduced from the observations of 
three summers, winters, and years. The last line in the table to which the 
word " Means " is prefixed, exhibits the mean tension in each month as de- 
duced from all the separate monthly observations ; i. e. the mean tension of 
January, 150'7 div., is the result of all the January observations in the three 
years. The same thing holds good of the seasonal and yearly mean ten- 
sions. 

The curves projected from these numbers will be found on Plate IX. 

The tensions that enter into the preceding discussion range between 2 
div. and 2000 div. in terms of Volta's standard electrometer No. 1. It has 
however been considered that tensions above 100 div. of this electrometer, 
or those measured by Henley's instrument, are not susceptible of that accu- 
racy of determination which is requisite in the deduction of results, such as 
characterize those of modern science. In addition to this, it is apprehended 
that the electrical tension known more particularly as the tension of serene 
weather, seldom (if at all) rises above 100 div., although there may be move- 
ments indicated by Henley's instrument which partake of the character of 
those of serene weather. 

In immediate reference to these points, and considerably elucidating them, 
remarks occur, either in the body of the Journal or in the notes and addenda 
accompanying it. In the description of the instruments at Kew published in 
the volume for IS^^ (Reports, 1844, p. 124), the following occurs in refer- 
ence to Henley's instrument : — 

" This electrometer has seldom been observed until the Volta No. 2 had 
risen beyond 90° (in terms of the first, i. e. 18 lines x 5) ; and since the un- 
certainty and difficulty of measuring the higher tensions increase in a rapid 
ratio with the increments of tension owing to unavoidable and sometimes 
almost imperceptible ' spirtings,' and particularly to the falling of rain from 
the dish or funnel N (fig. 2), proportionably less confidence must, of course, 
be placed in our notations of such tensions by means of this instrument." 

In the account of the experiments having reference to the employment of 
photographic methods for self-registering the indications of the instruments, 
which is appended to the volume of observations 1845 and 1846, we have 
the following remark relative to the objection of the Astronomer Royal as to 
the non-registry of the kind of electricity : — 

" I had not of course overlooked the objection as to not registering the 
kind of electricity, but as every former observer of the periodical electricity 
of serene weather, (i. e.) that alone which is susceptible of exact measure- 
ment, and that which is by far the most important and interesting, had ar- 
, rived at the same conclusion as myself, (viz.) that it is positive, and that the 
exceptions to this law are extremely rare, and always accompanied by an easily 
distinguished feature in meteorology." 

In the above extracts we have clearly a restriction of the electricity of 
seretie weather to a comparatively low tension, and that the higher tensions, 
although more difficult to measure accurately, are not near so important as 
those which characterize serene weather. In immediate connection with this 
comparatively low tension we have the following remark, recorded on June 23, 
: 1844 :— 

" The weather of this day, considered as serene, has been rather remark- 
able. The signs a little after sunrise were the highestybr such weather that 
we have had. The thermometer at nine stood at75'5, the max. also, and the 
barometer at 29"938. The atmosphere quite clear ; the clouds were light, 



128 REPORT— 1849. 

rather fleecy, roundish and somewhat detached. Wind N.E. and E., its force 
about 500 grms. Daniell's hygrometer marked 20° of dryness." 

At sunrise the electric tension was registered at 65 div. Volta No. 1 . From 
this it appears that a tension of 65 div. at sunrise is considered as liigh for 
serene weather, and it might be inferred that tensions of a higher value indi- 
cated some other exciting cause than that which we contemplate as exciting 
the electricity of serene weather. 

In the explanations and remarks concerning the Journal, Sac. at Kew, pub- 
lished in the Report for 1844, p. ISO, a serene day is defined as follows : " In 
the column N is pointed out (by the letter S) such days as generally occur 
when the positive charge rises after sunrise, falls early in the afternoon, and 
rises again in the evening, accompanied by what is commonly understood by 
the term ' fine weather ;' but there are exceptions to this (rather vague) de- 
finition, which I believe require some habit, and an acquaintance with the 
observations of Monier and others, particularly Beccaria, to appreciate." 

By glancing at the curves on pages 1 19 and 122, to which attention has been 
solicited, it will be seen that the movements, as deduced from the observa- 
tions in individual years and seasons, as well as those from the entire number 
during the three years, are perfectly in accordance with the movements in 
serene weather, and it is only the I'estriction to which allusion has been made 
that suggests the probability of the higher tensions being due to a different 
exciting cause than that of the electricity of serene weather. In searching 
for such a cause among the records preserved in the Journal, we are struck 
with the fact, that in the majority of cases high tensions {i. e. those measured 
by Henley's electrometer) are accompanied by fog ; and this suggests that it 
is not improbable that these high tensions may be more or less direct mea- 
sures of the electricit)', not of the atmosphere, but of the condensed aqueous 
vapour enveloping the collecting lanthorn. Of course the atmospheric 
electricity, as contradistinguished from that of the condensed aqueous vapour, 
will be mixed with it, and the conductor will be charged from two different 
sources, the atmospheric electricity exhibiting by far the smallest amount, 
and in cases of high charges forming probably but a very small proportion 
of the whole. There does not appear to be any direct means of separating 
these tensions ; for if we take the hiffh numbers, a small proportion, as we 
have already said, must appertain to " atmospheric electricity ;" and if we 
take the loto numbers as giving a more accurate measure of this element, on 
some occasions and especially at certain hours, the tensions exhibited may 
be those produced by the presence of aqueous vapour either in an invisible 
or condensed state, so that a degree of uncertainty as to the true forms of 
either of these diurnal curves must necessarily exist. Again, it is difficult to 
determine the point at which to separate the high from the low tensions ; the 
uncertainty attendant on the readings of Henley's electrometer, combined 
with the electricity which alone is susceptible of exact measurement, tends 
greatly to place all readings of Henley's instrument in the category of high 
tensions. As a first attempt to separate the high from the low tensions, 1° 
of Henley equal to 100 div. of Volta No. 1 was regarded as the separating 
point; but it soon became apparent that readings lower than 100 div. had an 
equal claim to be regarded as high, indications being afforded that they were 
measures rather of the electricity of aqueous vapour than of the atmosphere. 
The observations of three or four months Mere discussed in this manner, but 
the curves of low tension presenting very anomalous characters, the mean 
readings increasing very considerably towards 8 p.m. led to their abandon- 
ment, and other separating points were tried from 50 div. and upwards. The 
result has been that the point 60 div. has been employed in the further discus- 



ON ELECTRICAL OBSERVATIONS AT KEW. 



129 



sions of the observations, all readings above and including it being regarded 
as high, and more or less measuring the electrical tension of aqueous vapour 
either invisible or condensed ; and all readings below it being regarded as 
more or less measuring the tension of " atmospheric electricity." Of course 
this method is entirely tentative ; the separating point 60 div. has been arbi- 
trarily fixed, and, as before observed, it is not to be expected that the curves 
furnished will be true representatives of natural phaenomena, when we come 
to contemplate the two different sources from which the conductor is sup- 
posed to be charged ; nevertheless it may not be without its use in assisting us 
to devise some mode by Avhich the two tensions may be effectually separated, 
either by some subsidiary observations and computations by which the elec- 
trical tension of the aqueous vapour may be disengaged from the aggregate 
tension as exhibited by the electrometers, or by directly observing the elec- 
trical tension of the vapour itself. 

Table XIX. 

4 ^ ^ < Mean diurnal period of low tension 

for the months of January, Fe- 
bruary, March and April IS-iS. 



April. 




Period. 


Jan. 


Feb. 


March. 


April. 


Midnight .. 

2 a.m 

4 a.m 

6 a.m 

8 a.m 

10 a.m. ... 

Noon 

2 p.m 

4 p.m 

6 p.m 

8 p.m 

10 p.m. ... 


14-5 
11-4 
18-2 

34'i" 
49-5 
41-1 
411 
530 
467 
51 
44-3 


22-2 
19-5 
18-9 

ii-o 

52-4 
58-6 
57-2 
59-7 
61-8 
72-9 
49-5 


22-0 
306 
23-6 

49'8 
50-6 
42 
49-7 
524 
50-2 
50-5 
48-4 


22-3 
17-7 
18-0 
28-0 
40-3 
44-0 
32-6 
37-3 
39-2 
42-2 
47-4 
43-0 


Means 


34-3 


45-6 


43-7 


35-1 



April. 

til 

'A 



The above table and curves are 
intended to illustrate the separation 
of the readings into those of high and 
low tensions. The table contains 
the diurnal periods for the first four 
months of the year IS^S, and the 
four upper curves are the projections 
of the.se periods on the same scale as 
the curves deduced from all the ob- 
servations. The four lower curves 
exhibit the diurnal period for the 
same months as deduced from the 
^ ° 2 « readings below 60 div. The greater 

uniformity of the lower curves, especially of January and February as com- 
pared with the upper, is very apparent. The curves appear naturally to 
divide themselves into two sets, the greater uniformity appertaining to 
January and February below 60 div., and to March and April, higher 
tensions than 60 div. entering as elements into the discussion of low ten- 
1849. K 



Below 
60 div. 



130 



REPORT 1849. 



sions. This seems at once to indicate the variability of any point that may 
be fixed on for the purpose of separating the two. Uniformity of curve 
clearly points out uniformity of action, and in endeavouring to obtain a 
knowledge of the action of the electricity of serene weather on the conductor 
and electrometers, it is to be presumed that it is to a great extent uniform 
and regular, and that consequently the curves will exhibit such uniformity 
and regularity among themselves. This then, in the absence of some direct 
means of measuring either the electricity of serene weather or of aqueous 
vapour, must be our principal guide in endeavouring to separate them ; and 
although on some occasions greater uniformity may be obtained by either 
including or excluding particular tensions, yet upon the whole great uncer- 
tainty must prevail, if we attempt to vary the point of separation without 
more conclusive data than the mere uniformity of curve. 

Diurnal period below 60 div., Year. — The 10,176 observations at all ten- 
sions are thus divided : — 

Below 60 div 7,529 

Above 60 div 2,647 

10,176 

Those below 60 div. are thus distributed among the twelve daily readings. 

Table XX. 

Number of positive readings below 60 div. at each observation-hour in the 
three years 1845, 1846 and 1847. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


Ga.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 


1845. 
1846. 
1847. 


222 
234 
199 


236 
257 
255 


243 
267 
286 


172 
170 
160 


249 
235 
229 


224 
214 
222 


202 
212 
213 


222 

195 
210 


215 

201 
209 


197 
171 
193 


172 
148 
161 


168 
181 
185 


2522 
2485 
2522 


Sums. 


655 


748 


796 


502 


713 


660 


627 


627 


625 


561 


481 


534 


7529 



From a consideration of the above quantities, we find that the greatest 
number of low tensions occurred at the hours 2, 4 and 8 a.m. ; 6 a.m. ap- 
pears to be excepted ; but we must bear in mind that the number 502 refers 
principally to the summer half-year; with this exception, the smallest number 
of low tensions occurred at 6, 8 and 10 p.m. It is to be remarked that these 
periods coincide, more or less, with the principal epochs of minimum and 
maximum, the whole of the observations being taken into account. 

Table XXI. 
Mean electrical tension below 60 div. at each observation-hour in the three 
years 1845, 1846 and 1847, with the mean diurnal period as deduced from 
the whole. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. Noon. 


2 p.m. 4 p.m. 


6 p.m. 


8p.m.'l0p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 
19-8 
24-3 
23-7 


div. 
17-8 
21-2 
21-1 


div. 

17-5 
21-0 
20-9 


div. 

19-4 
25-0 
27-1 


div. 
26-6 
30-5 
32-1 


div. 
28-7 
32-4 
36-0 


div. 
29-7 
31-3 
35-5 


div. 

31-4 
30-5 
33-9 


div. 

30-5 
32-0 
35-0 


div. 

30-5 
34-3 
37-5 


div. 
31-6 
35-0 
38-0 


div. 

30-8 
360 
39-2 


div. 
25-9 
28-8 
31-1 


Mean. 22-6 


20-1 


19-9 


23-7 


29-6 32-3 


322 320 


32-5 


34-1 


34-5 


35-5 28-6 



ON ELECTRICAL OBSERVATIONS AT KEW. 

Table XXII. 



131 



Excess or defect of the mean electrical tension below 60 div. at each obser- 
vation-hour, as compared with the mean of the year for the three years 
1845, 1846 and 1847j and the piean diurnal period. 



Yean 


Mid. 


2 a.m. 4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 


div. 

61 


div. 
8-1 


div. 
8-4 


div. 
6-5 


div. 
+ 

0-7 


div. 

+ 
2-8 


div. 
+ 
3-8 


div. 
+ 
5-5 


div. 
+ 
4-6 


div. 

+ 
4-6 


div. 


div. 
+ 
4-9 


div. 
25-9 


1846. 


4-5 


7-6 


7-8 


3-3 


+ 
1-7 


+ 
3-6 


+ 
2-5 


+ 
1-7 


+ 
3-2 


+ 
5-5 


+ 
6-2 


+ 
7-2 


28-8 


1847. 


7-4 


10-0 


10-2 


40 


+ 
10 


+ 
4-9 


+ 
4-4 


+ 
2-8 


+ 
3-9 


+ 
6-4 


+ 
6-9 


+ 
8-1 


31-1 


Mean. 


6-0 


8-5 


8-7 


4-9 


+ 
10 


+ 
3-7 


+ 
3-6 


+ 
3-4 


3-9 


+ 
5-5 


+ 
6-2 


+ 
6-9 


28-6 



In the above tables the double progression, so apparent in the curves de- 
duced from all the positive observations, is but slightly developed. The fore- 
noon maximum at 10 a.m. rises very slightly above the afternoon minimum 
at 2 P.M. — only 0*3 div. The evening and principal maximum occurs at 10p.m., 
presenting the highest mean reading of the series. The year 1847 is marked 
by an increase in the low as well as in the aggregate tension, this increase 
appearing after the hour of 4 a.m. If the separation of the high from the 
low tensions at the point of 60 div. be that which is most accordant with 
truth, and the above tables exhibit more accurately the movements during 
serene weather than those which form the preceding part of this discussion, 
it would appear that upon contemplating the movements as deduced from the 
three years, there exists a great tendency to soften down or even to obliterate 
the forenoon maximum in such movements, so as to exhibit an approach to 
a single progression. The departure from an exhibition of the true march of 
the electricity of serene weather by the numbers before us, has been alluded 
to, inasmuch as the same cause, viz. the presence of aqueous vapour, must 
influence the results as deduced from the lower as well as those from the 
higher readings, and it becomes a curious matter of inquiry as to how far 
both the subdued maximum of the forenoon and the more decidedly deve- 
loped maximum of the evening, in the progression of the lower tension, may 
be due to the presence of such vapour. It is a matter worthy of remark, and 
certainly is not without great signification, that the curves already discussed 
agree in presenting a precipitous downward movement between 10 p.m. and 
midnight. The tables now under consideration present in a very decided manner 
the same feature: although the extent of the diminution of tension is not so 
great as in the aggregate curves, yet as compared with the other two-hourly 
movements, it is sufficiently large to constitute a marked contrast to them, 
and this is by no means to be confined to the tensions we have hitherto ex- 
amined ; it will be found as we proceed to be an invariable accompaniment 
to nearly the whole of the curves. 

The mean of the 7529 observations below 60 div. is 28*6 div., or ,S8*3 div. 
lower than the mean of the 10,176 positive observations. The minimum 
occurs at 4 a.m., from which hour the tension gradually rises until 10 a.m.; 
a very slight depression of 03 div. then takes place, the turning-point being 
at 2 p.m., from which hour the rise is very gradual until 10 p.m., the prin- 
cipal maximum, which b immediately succeeded by the precipitous diminu- 

k2 



132 



RKPORT 1849. 



tion above mentioned. These phaenomena are rendered more apparent by 
the annexed curves, fig. 6. 



4 A.M. 10 A.M. 



10 P.M. 2 a.m. O 



CO 



1847 



3 years 




In the following table, the diur- 
nal periods, as deduced from the 
aggregate observations and from 
those below 60 div., are placed in 
contrast. 



P.M. 2 A.M. 



Table XXIII. 
Comparison of the excess or defect from the mean of the diurnal periods of 
the entire year, as deduced from the aggregate observations and from 
those below 60 div. 



Value. 


Mid. 


2a.ni. 


4 am. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 




— 


— 


— 


— 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 




Aggregate ... 


44-3 


46-8 


46-4 


32-7 


13 


21-2 


8-5 


4-6 


2-2 


17-9 


35-5 


37-1 


66-9 




— 


_ 


_ 


_ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 




Below 60 div. 


60 


8-5 


8-7 


4-9 


1-0 


3-7 


36 


3-4 


3-9 


5-5 


6-2 


6-9 


28-6 



Dkirnal period below 60 div., Summer. — The 7529 observations below 
60 div. are thus distributed in the two half-years : — 

Summer 4846 

Winter 2683 

7529 



ON ELECTRlCAIi OBSERVATIONS AT KEW. 



133 



The following table exhibits the distribution of the 484i6 summer obser- 
rations among the twelve daily readings : — 

Table XXIV. 

Number of positive readings below 60 div. at each observation-hour in the 

three summers of IS^S, 1846 and 1847. 



Year. 


Mid, 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8p.m 


10 p.m. 


Sums. 


1845. 
1846. 
1847. 


133 
140 
125 


135 
149 
148 


144 
153 
160 


160 
158 
154 


148 
138 
134 


148 
139 
138 


126 
137 
133 


139 
129 
131 


136 
129 
131 


128 
121 
127 


116 
102 
112 


103 
119 
121 


1618 
1614 
1614 


Sums. 


400 


432 


457 


472 


420 


425 


396 


399 


396 


376 1 330 


343 


4846 



This table exhibits a more equable distribution of observations over the 
twenty-four hours than that which has reference to the entire year ; the 
greatest number occurs at 6 a.m., and the smallest at 8 p.m. 

Table XXV. 

Mean electrical tension below 60 div. at each observation-hour in the three 
summers of 1845, 1846 and 1847, with the mean diurnal period of summer. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


j a.m. 


I0a.ra. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


3 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 
19.6 
21-0 
23-5 


div. 

160 
17-4 
200 


div. 
15-8 
18-7 
18-9 


div. 

19-9 
24-4 
26-9 


div. 
24-5 
29-0 
32-3 


div. 
27-3 
301 
35-6 


div. 

26-6 
27-5 
34-0 


div. 
29-3 
27-0 
32-2 


div. 
28-4 
28-2 
33-8 


div. 
29-8 
31-2 
35-4 


div. 
31-7 
31-2 
37-4 


div. 

31-7 
33-3 
39-6 


div. 
24-7 
26-2 
30-3 


Mean. 


21-3 


17-8 


17-8 


23-7 


28-5 


30-9 


29-4 


29-5 


301 


321 


33-5 


350 


271 



Table XXVI. 
Excess or defect of the mean electrical tension below 60 div. at each obser- 
vation-hour, as compared with the mean of each summer in the years 1845, 
1846 and 1847, and the mean of the three summers. 





Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 






— 


— 


— 


— 


— 


+ 


+ 


-t- 


+ 


+ 


+ 


+ 






1845. 


51 


8-7 


8-9 


4-8 


0-2 


2-6 


1-9 


4-6 


3-7 


5-1 


7-0 


7-0 


24-7 






— 


— 


— 


— 


+ 


+ 


+ 


+ 


+ 


-f- 


+ 


+ 






1846. 


5-2 


8-8 


7-5 


1-8 


2-8 


3-9 


1-3 


0-8 


20 


5-0 


50 


7-1 


26-2 






— 


— 


— 


— 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 






1847. 


6-8 


10-3 


11-4 


3-4 


2-0 


5-3 


3-7 


1-9 


3-5 


5-1 


7-1 


9-3 


30-3 




_ 


_ 


_ 


_ 


+ 


+ 


+ 


+ 


+ 


-1- 


-f 


+ 






Mean. 


5-8 


9-3 


9-3 


3-4 


1-4 


3-8 


2-3 


2-4 


3-0 


50 


6-4 


7-9 


271 



In these tables we find the forenoon maximum developed in a greater de- 
gree than in those having reference to the entire year — a result to be expected 
if the notion be correct that both low and liigh tensions are influenced by the 
presence of aqueous vapour in the atmosphere. The number of observations 
on which these tables are based forms a very considerable portion of the Avhole 
of the summer observations — rather above seven-eighths. The entire num- 
ber is 5514, from which deduct those below 60 div,, and we have left 668, or 
nearly an eighth part of the whole, so that the probability of the forenoon 
and evening maxima resulting from the presence of aqueous vapour is 



134 



REPORT — 1849. 



rendered more apparent in the summer than during the entire year. It is 
important here to remark, that the results obtained by separating the sum- 
mer observations from those of the entire year below 60 div. are of an oppo- 
site character to those obtained by dividing the aggregate observations into 
summer and winter series. In the case of the aggregate observations we 
found the summer curves representing the diurnal march, less in extent and 
less abrupt in their character than those of the entire year. On the con- 
trary, we find the summer observations of low tension rather bolder in their 
character and of greater range than those of the entire year. In the former 
case, that of the aggregate observations, the summer readings were as a mass 
much lower than those of the winter ; there were also a much greater num- 
ber that would have especial reference to serene iveather than of those in the 
winter, and these circumstances would reduce the summer curves to the form 
in which we find them. When however we contemplate the tensions below 
60 div., there is nothing cut oft' in the summer from those furnishing the re- 
sults of the year, the whole of the observations up to and including 59 div. 
finding entry at all seasons ; but we have a much greater number of low ten- 
sions during the summer than in the winter, so that a greater portion of the 
entire phaenomena is as it were compressed into the lower readings, and ma- 
nifests itself by expanding the summer curves as compared with those of the 
entire year rather than contracting them. 

g M In tracing the diurnal march of 

S S J the tension below 60 div., we find 

4 A.M. 10 A.M. 10 P.M. 2 a.m. I tiie minimum occurring at 2 and 
^ 4 A.M. ; after 4 a.m. the tension 
Mean - gradually rises until 10 a.m., the 
"g epoch of the forenoon maximum ; 
o a fall of V5 div. occurs between 
2 10 A.M. and noon, after which a 
5 very gradual and regular rise takes 
Z place until 10 p.>r., the epoch of 
2 the evening maximum, which is 
S i succeeded by the precipitous di- 
Mean. 3 1 minution of tension already al- 
J I luded to. In the diurnal mini- 
^ g mum occurring at noon, and its 
>5 being followed by a gentle rise to 
o.| the evening maximum, we have re- 
s's peated to a certain extent the same 
■3 £ feature which we noticed as cha- 
% ^ racterizing the summer curve ot 
1 1 the aggregate observations. There 
~ is however one important point of 
■J difference which strikingly exhi- 
s. bits the influence of the higher 
^ tensions on the curves : the hours 
^ of maxima and minima are nearly 
Mean. § if not tile same in both cases, and 
g the gentle rise from noon to 4 p.m. 
g in each instance possesses many 
J features in common, the principal 
10 p.m. 2a.m. c difierence being a greater move- 
»j g ment in the aggregate than in the 

^ low tensions. The point of differ- 







4 a.m. 10 am. 



ON ELECTRICAL OBSERVATIONS AT KEW. 



135 



ence to which we particularly solicit attention is the augmentation in the 
summer curves of low tension of the forenoon and evening maxima, and their 
contraction in the aggregate summer curves. This is very apparent on con- 
sulting the curves. In discussing the high tension during the summer months, 
this subject will be again referred to ; in the mean time we may notice here, 
that upon the consideration of the high readings measuring the electrical ten- 
sion of aqueous vapour, it appears probable that these maxima depend on 
the presence of aqueous vapour for their development. 

Table XXVII. 

Range of the diurnal curves of electric tension below 60 div. in the summers 
of 1845, 1846 and 1847, and also in each year. 



Year. 


Summer 
curve. 


Yearly 
curve. 


1845. 
1846. 

1847. 

Mean. 


div. 
15-9 
15-9 
20-7 

17-2 


div. 
14-1 
15-0 
18-3 

15-6 



Table XXVIII. 
Comparison of the excess or defect from the mean of the diurnal periods of 
summer, as deduced Irom the aggregate observations and from those below 
60 div. 



Value. 


Mid. 


2 a.m. 


4 a.m. 6 a.m. 


8 a.m. 


] a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Means. 




div. 


div. 


div. div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


Aggregate ... 


15-9 


19-4 


18-3 4-0 


+ 
6-4 


+ 

9-5 


3-8 


2-1 


2-0 


+ 
1-7 


+ 
13-6 


+ 
26-2 


37-2 


Below 60 div. 


5-8 


9-3 


9-3 3-4 


+ 
1-4 


+ 
3-8 


+ 
2-3 


+ 
2-4 


+ 
3-0 


+ 
50 


+ 
6-4 


+ 
7-9 


27-1 



The above table places the aggregate and lov.' tension summer diurnal 
periods in contrast. 

Diurnal period helow 60 div.. Winter. — The following table exhibits the 
distribution of observations below 60 div. during the winter among the twelve 
daily readings. 

Table XXIX. 

Number of positive readings below 60 div. at each observation-hour in the 

three winters of 1845, 1846 and 1847. 



Year. 


Mid.[2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m.lNoon. 

1 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Suras. 


1845. 
1846. 
1847. 


87 
94 
74 


101 

108 
107 


99 
114 
126 


12 

12 

6 


101 
97 
95 


76 
75 
84 


76 
75 
80 


83 
66 
79 


79 
72 

78 


69 
50 
66 


56 
46 
49 


65 
62 
64 


904 
871 
908 


Sums. 


255 316 339 


30 


293 


235 


231 


228 229 


185 


151 


191 


2683 



In this table, the greatest numoer of readings occur at 4 a.m., the epoch 
of the principal minimum, and the least number at 8 p.m., two hours after 
the evening maximum. It will be remarked, that the morning hours, viz. 2 
and 4 a.m., exhibit the greatest numbei", and the evening hours,- 6, 8 and 
10 P.M., the least. The thirty readings at 6 a.m. ai'e excepted, for the reason 
stated on page 1 30. 



136 



REPORT 1849. 



Table XXX. 

Mean electrical tension below 60 div. at each observation-hour in the three 
winters of 1845, 184-6 and 184'7, with the mean diurnal period of winter. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 

20-1 
29-2 
23-9 


div. 

20-2 
26-5 
22-7 


div. 
19-8 
24-2 
23-6 


div. 

13-2 
321 
32-9 


div. 

29-6 
32-5 
31-7 


div. 
31-4 
36-6 
36-8 


div. 
34-8 
38-3 
380 


div. 

34-8 
37-5 
36-8 


div. 
34-2 
38-8 
37-1 


div. 

31-7 
420 
41-5 


div. 
31-5 
43-4 
39-4 


div. 
29-2 
41-3 
38-4 


div. 
28-1 
33-8 
32-4 


Meau. 


24-5 


23-2 


22-7 


24-7 


31-2 


350 


371 


36-3 


36-6 


38-0 


37-7 


36-2 


31-4 



Table XXXI. — Excess or defect of the mean electrical tension below 60 div. 
at each observation-hour, as compared with the mean of each winter in the 
years 1845, 1846 and 1847, and the mean of the three winters. 



Year. 


Mid. 


2 a.m. 


4 a.m. 6 a.m. 


8 a.m. 


10 a.m. 


Noon. 2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 


div. 

8-0 
4-6 
8-5 


div. 

7-9 
7-3 
9-7 


div. 
8-3 
9-6 
8-8 


div. 
14-9 

1-7 

+ 
0-5 


div. 

+ 
1-5 

1-3 

0-7 


div. 
+ 
3-3 

+ 
2-8 

+ 
4-4 


div. 

+ 
6-7 
+ 
4-5 

+ 
5-6 


div. 

+ 

6-7 
+ 
3-7 

+ 
4-4 


div. 
+ 
61 

+ 
5-0 

+ 
4-7 


div. 

+ 

3-6 

+ 
8-2 
+ 
9-1 


div. 
+ 

3-4 

+ 
96 

+ 
7-0 


div. 

+ 
11 
+ 
7-5 

+ 
60 


div. 

281 
33-8 
32-4 


Mean. 


6-9 


8-2 


8-7 


6-7 


0-2 


4- 
3-6 


+ 
5-7 


+ 
4-9 


+ 
5-2 


+ 
6-6 


+ 
6-3 


+ 
4-8 


31-4 



4 a.m. 10 a.m. 



10 P.M. 2 a.m. 



In order to facilitate the compari- 
S son of the diurnal march of the low 
■a tensions during the individual winters, 

which present some striking features 
2 of interest, we shall at once introduce 
^" the curves to the notice of the reader. 
Z On contemplating them, it will be at 
2 once apparent that they present se- 
c ^ veral interesting points of contrast. 
*S There appears to be a greater ap- 
■^1 proach to a single progression, espe- 
"^ 2 cially in the winter of 1845. In this 
4" curve the maximum occurs at noon 
S5 and 2 p.m.; the precipitous diminu- 

1 ° tion between 10 p.m. and midnight 
•° § disappears, the curve taking a gently 
•I s rounded course from 2 p.m. to mid- 
I g night ; tliere appears to be a slight 
S 2 check to this gradual diminution of 
|i tension at 8 p.m. The principal nii- 
"^ ^ nimum occurs at 6 a.m., the rise from 
- this hour to noon being of a bold, 
° rounded character ; it is probable that 
E the true minimum occurs at 4 a.m., 
" twelve observations only contributing 
g to the determination of the value at 
=3 6 A.M. On contrasting this curve 
I with those of the summer and entire 
^ year aggregate tension, we find the 

movements during the day reversed, 
the greatest development occurring about the middle of the day. A much 



1847.- 



4 A.M, 10 A.M. 



10 P.M. 2 A.M. 



ON ELECTRICAL OBSERVATIONS AT KBW. 



137 



greater number of observations of high tensions contribute to the production 
of the aggregate curve in winter than in summer, and as a consequence, the 
observations on which the winter curve of low tension is based are less nu- 
merous than those on which the summer curve rests. In the curve now 
before us, the double progression may be considered if not entirely, as almost 
disappearing ; the removal of the higher tensions appears to be accompanied 
by a removal of the forenoon and evening maxima, which is replaced by a 
maximum near the middle of the day. This is extremely striking when we 
compare our curve with that of the winter, as deduced from all the positive 
readings (page 122); in this curve the forenoon and evening maxima are 
strongly developed, and the depression at 2 and 4 p.m. very distinctly marked. 
It would appear, on the supposition of the high readings being measures of 
the electrical tension of aqueous vapour, that in this particular winter (1845), 
very few measures of such tensions occurred below 60 div., so that in the 
great majority of instances, the readings below 60 div. were, more or less, 
measures of atmospheric electricity. The curve itself suggests the inquiry — 
Is the diurnal march of atmospheric electricity — viz. that which is uncombined 
with the electrical tension characterizing, or developed by, the presence of 
aqueous vapour — a single progression ? In other words, does the electrical 
tension of dry air present a curve having simply an ascending and descending 
branch, the progression being in harmony with the temperature ? We shall 
have occasion to refer again to this subject in a future part of this Report. 

On turning our attention to the winter of 1846, we find a curve more or 
less in harmony with those of the summer and entire year, and strikingly in 
contrast with that of the winter of 1845. It is however to be remarked, that 
the depression at 2 p.m. is but slight, and very much less than the depression 
during the summer of this year ; the slight check which is apparent in the 
forenoon rise, at 8 a.m., tends to give the curve an appearance of possessing 
three maxima ; there is indeed a great tendency to assume somewhat of the 
form of 1845, which appears to be counteracted by the greater development 
of the evening maximum. 

The winter curve of 1847 may be characterized as exhibiting considerable 
trepidation, and consisting of alternate but very subordinate maxima and 
minima, the principal of which occurs at 6 p.m. There is an evident ten- 
dency to a single progression, having its maximum about the early afternoon 
hours. This curve is in contrast with that of the winter of 1845, inasmuch 
as the most rounded portion of the curve is developed in the evening. 

On directing our attention to the mean of the three winters, we find two 
maxima, noon and evening, well-developed, but of a subdued character. The 
evening maximum is the principal ; it however rises only 0*9 div. above that 
at noon ; the intermediate minimum occurs at 2 p.m., and is depressed T? div. 
below the principal maximum. 

Table XXXII. 
Synopsis of the principal points in the summer, winter, and yearly curves 

below 60 div. 



Season. 


Forenoon 
Maximum. 


Minimum. 


Evening 
Maximum. 


Nocturnal 
Minimum. 


Even. Max. 

above 
Forenoon. 


Aftern.Min. 

below 
Even. Max. 


Summer. 
Winter... 
Year .... 


10 a.m. 
Noon. 
10 a.m. 


Noon. 
2 p.m. 
2 p.m. 


10 p.m. 

6 p.m. 

10 p.m. 


2 & 4 a.m. 
4 a.m. 
4 a.m. 


div. 
4-1 

0-9 

3-2 


div. 
5-6 

1-7 

3-5 



138 



REPORT — 1849. 



This subdued character of the two maxima, as well as the comparatively 
slight depression of the included minimum, is well seen in the above table ; 
and when combined with the characters of the individual curves of each 
winter which have been noticed above, together with the approach of the 
epochs of maxima in the mean curve to each other, viz. from 10 a.m. to noon, 
and from 10 p.m. to 6 p.m., a strong probability is suggested, that were we 
able effectually to separate the high from the low tensions, not at an arbitrary 
point, but in such a manner that the high tensions of summer (in all proba- 
bility lower than those of winter) should find entry in their respective de- 
partment, the result would be, that the low tensions would exhibit a single 
progression in harmony with the temperature. 

In the following table the diurnal periods for the winter, as deduced from 
the aggregate and low tensions, are placed in contrast. 

Table XXXIII. 

Comparison of the excess or defect from the mean of the diurnal periods 
of winter, as deduced from the aggregate observations and from those be- 
low 60 div. 



Value. 


Mid 


2 a.m. 


4 a.m. 6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 




div. 


div. 


div. div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 








— 


— 


— 


+ 


+ 


+ 


— 


+ 


+ 


+ 




Aggregate .. 


77-6 


78-9 


79-4 


55-6 


90 


27-9 


13-7 


3-9 


0-6 


27-3 


55-2 


43-4 


102-1 




— 


— 


— 


— 


— 


+ 


+ 


+ 


4- 


+ 


+ 


+ 




Below60div. 


6-9 


8-2 


8-7 


6-7 


0-2 


3-6 


5-7 


4-9 


5-2 


6-6 


6-3 


4-8 


31-4 



Tables XXXIV., XXXV., XXXVI. exhibit the mean electrical tension at 
each observation-hour for each month in the three years IS^S, 184-6 and 
1847, with the monthly seasonal and yearly means. Tiie characters of the 
monthly movements are exhibited to the eye in the sheets of curves illus- 
trating this report. See Plates VI. VII. and VIII. 

Table XXXVII. exhibits the mean monthly electrical tension at each 
observation-hour deduced from the observations of three months, also the 
mean summer, winter, and yeaily tension deduced from the observations of 
three summers, winters, and years. The last line in the table, to which the 
word " Means" is prefixed, exhibits the mean tension in eacii month as de- 
duced from all the separate monthly observations, i. e. the mean tension of 
January, 31*5 div. is the result of all the January observations in the three 
years. The same thing holds good of the seasonal and yearly mean tensions. 

The curves projected from these numbers will be found on Plate IX. 

Previous to proceeding with the discussion of the high tensions, it will be 
advantageous to pause, for the purpose of recapitulating the principal points 
that have hitherto come under our notice, and of particularly directing our 
attention to those that stand out prominently from among the others. 

1. We have seen that the discussion of the entire series of the positive 
observations for the three years furnishes us witli series of curves, exhibiting 
in a most decided manner a double progression. The points of maxima and 
minima are well-marked, and in most cases they present a tolerable fixity of 
epoch. 

2. The presence o{ fog mostly occurring on those occasions when higJi 
electrical tensions have been observed, combined with the opinion that the 
electricity of screqe weather is mostly characterized by low tensions, has 



ON ELECTRICAL OBSERVATIONS AT KEW. 



139 



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ON ELECTRICAL OBSERVATIONS AT KEW. 



141 



suggested the probability that the forenoon and evening maxima result more 
or less from the presence of aqueous vapour, either in an invisible or con- 
densed state. 

3. With a view to submit this notion to the test of observation, an attempt 
has been made (it must be confessed of a very rough and arbitrary character) 
to separate the high from the low tensions; the point 60div. of Volta's elec- 
trometer No. 1 has been provisionally assumed as the separating point, and 
all tensions above it have been regarded as high, those below it the converse. 
The result of this separation, so far as the low tensions are concerned, has 
been to exhibit series of curves, those of the summer and entire year being 
somewhat in harmony with the aggregate curves for the same periods ; the 
forenoon and evening maxima however are greatly subdued, but still the 
evening holds the most prominent position. The curves of the entire year 
suggest the probability that a single progression would be obtained on the 
removal of the two maxima. 

4. The winter curves of low tension strongly confirm this suggestion. The 
approach to a single progression is very apparent in the winters of 1845 and 
1847 ; the mean curve however still presents the two maxima, although their 
altitudes are considerably more equal in value than any of the curves yet 
contemplated ; their interval in time (6 hours) is also less than most of the 
others, especially the aggregate curves, the most usual interval of these being 
12 hours. 

5. ThQ salient points characterizing the two series of curves (aggregate 
and low tension) are a decided development of the forenoon and evening 
maxima in the aggregate, and a considerable subduing of these features with 
an approach to a single progression in the low. 



Diurnal period above 60 div., Year. — We are now prepared to enter on the 
discussion of the high tensions, with the expectation that the two maxima so 
prominently developed in the aggregate curves will form very decided fea- 
tures in those deduced from observations above 60 div. It is necessary to 
observe here, that the observations above 60 div. will not furnish the entire 
diurnal march of the high tensions, none being recorded at the hours of mid- 
night and 2 a.m. ; very few indeed are entered at 4 a.m. ; and those finding 
entrance at 6 a.m. being mostly confined to the summer half-year, the diur- 
nal march cannot be accurately said to commence until 8 a.m. In the fol- 
lowing tables and curves, with the exception of those having reference to the 
summer half-year, the diurnal march is given between 8 a.m. and 10 p.m. 
inclusive; in the summer it commences two hours earlier. 

The 2647 high readings during the three years are thus divided among the 
twelve observation-hours : — 

Table XXXVIII. 

Kumber of positive readings above 60 div. at each observation-hour in the 

three years 1845, 1846 and 1847. 



Year. 

1845. 
1846. 
1847. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 






3 
2 
3 


18 
20 
26 


92 
118 
124 


103 
124 
126 


73 
76 
72 


75 
83 
73 


87 
86 
80 


107 

110 

96 


130 
138 
129 


164 
157 
152 


852 
914 

881 






Sums. 






8 


64 


334 


353 


221 


231 


253 


313 


397 


473 


2647 



In connection with this table it will be observed that it furnishes two 



142 



REPORT — 1849. 



periods, each being marked by a greater number of readings than the inter- 
mediate period between them. Of these, the last, viz. that occurring at 6, 8 
and 10 P.M., presents the greatest number of observations, and it is to be no- 
ticed, that both periods coincide with the epochs of the forenoon and even- 
ing maxima, as developed in the aggregate curves. This of itself indicates 
that the greatest number of high readings occur at those epochs, and that 
the maxima result more from a systematic occurrence of the high than the 
low readings. There is a difference between the greatest number, 473, at 
10 P.M., and the smallest (excluding 4 and 6 a.m.), 221, at noon of 252. 



Table XXXIX. 

Mean electrical tension above 60 div. at each observation-hour in the three 
years 1845, 1846 and 1847, with the mean diurnal period as deduced from 
the whole. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 






div. 
85-0 
72-5 
70-8 


div. 

116-7 
123-9 


div. 

167-7 
122-2 


div. 

205-6 
1532 
219-6 


div. 

1737 
176-3 
244-9 


div. 
144-3 
147-6 
249-2 


div. 

130-2 
137-2 
215-5 


div. 
1460 
163-9 
222-8 


div. 

187-9 
162-1 
204-4 


div. 
205-8 
146-2 
191-6 


div. 
173-2 
149-7 
205-6 






110-0 164-7 


Mean. 






76-6 


116-2 


150-5 


192-2 


197-8 178-6 


159-6 


175-8 


184-3 


181-5 


175-9 



Table XL. 

Excess or defect of the mean electrical tension above 60 div. at each ob- 
servation-hour, as compared with the mean of the year for the three years 
1845, 1846 and 1847, and the mean diurnal period. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 

Mean. 






div. 

88-2 

_ 

77-2 
134-8 


div. 
56-5 
25-8 
95-6 


div. 

5-5 
27-5 
40-9 


div. 

+ 

32-4 

+ 

3-5 

+ 

14-0 


div. 
+ 
0-5 

■f 
26-6 

+ 
39-3 


div. 
28-9 

2-1 

+ 
43-6 


div. 
43-0 

12-5 

+ 
9-9 


div. 

27-2 

+ 
14-2 

+ 
17-2 


div. 

+ 
14-7 

+ 
12-4 

1-2 


div. 

+ 

32-6 

3-5 

140 


div. 
173-2 
149-7 
205-6 










99-3 


59-7 


_ 
25-4 


+ 
16-3 


+ 
21-9 


+ 
2-7 


16-3 


0-1 


+ 
8-4 


+ 
5-6 


175-9 



Although the movements, as exhibited in the above tables, are decidedly 
irregular, yet the indications of a double progression are by no means deficient ; 
they appear very prominently in the period for the year 1845. In this year 
the rise is very regular until 10 a.m., after which a fall, quite as regular, takes 
place between 10 a.m. and 4 p.m., and then the tension increases quite as re- 
gularly until 10 P.M. In 1846 and 1847 these movements are not so distinct, 
especially in the latter year, in which a great tendency to a single maximum 
about 2 P.M. occurs; there is however a subordinate maximum at 6 p.m. In 
1846 the two maxima are developed, the forenoon being the principal. The 
mean curve of the three years exhibits a period of tolerable regularity, in 
which the two maxima are well-marked, that of the forenoon being the highest', 
the epochs are noon and 8 p.m. 



ox ELECTRICAL OBSERVATIONS AT KEW. 



143 



4 A.M. 10 A.M. 



10 P.M. 2 A.M. 



1846,— 



CD 

s 



S years 




Mean. .^ 



4 AiM. 10 A.M. 10 P.M. 2 A.M. 



Previous to examining the summer 
curves of liigli tension, it will be de- 
sirable to direct our attention to those 
of the winter ; two circumstances con- 
tribute to this mode of proceeding. 
In discussing the curves of low ten- 
sion, we found the greatest approach 
to a single progression occurring in 
the winter, and this would suggest 
that in the same season we ought to 
find the most decided development of 
the two maxima in the curves of high 
tension, which give to the aggregate 
curves the feature of a double pro- 
gression. The great majority of read- 
ings during the summer being below 
60 div., those above will be consider- 
ably less in number than the high 
readings in the winter, and it is con- 
sequently to be expected that the 
movements of the high tensions (sim- 
ply considered as such) will be much 
more irregular in the summer than in 
the winter : in a word, if we can at 
all find any unequivocal indications 
of regularity of movement among the 
high tensions, we are much more likely 
to find them in the winter than in the 
summer. 

Diurnal period above 60 div.. Win' 
ter. — The entire number of high read- 
ings, 2647, is thus divided : — 

Winter 1979 

Summer 668 

2647 
The following table exhibits the 
distribution of the winter observations 
over the twelve observation-hours : — 



Table XLI. 

Kumber of positive readings above 60 div. at each observation-hour in the 

three winters of 1845, 1846 and 1847. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 


1845. 
1846. 
1847. 









2 
6 
3 


66 

81 
80 


84 
93 
91 


64 
71 
66 


68 
77 
67 


74 
76 
70 


83 
93 
83 


88 
92 
94 


96 
107 
104 


625 
696 
658 


Sums. 








11 


227 


268 


201 


212 


220 


259 


274 


307 


1979 



It will be seen from these numbers that the distribution of readings some- 
what assimilates to that of the entire year, being more numerous about the 



144 



REPORT — 1849. 



epochs of the forenoon and evening maxima. It is however much more 
equable, the difference between the greatest and least numbers, excluding the 
11 at 6 A.M., being only 106. A proportionate regularity in the diurnal march 
may consequently be expected. 

Table XLII. 

Mean electrical tension above 60 div. at each observation-hour in the three 
winters of 1845, 1846 and 1847, with tlie mean diurnal period of winter. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 








div. 

85-0 

83-3 

165-0 


div. 

184-8 
130-4 
206-0 


div. 
231-1 
163-2 
248-0 


div. 

188-0 
171-9 
261-1 


div. 
146-6 
145-0 
257-1 


div. 

139-6 
136-9 
235-0 


div. 
1670 
174-5 
244-8 


div. 
223-1 
198-7 
247-4 


div. 
259-1 
164-7 
221-8 


div. 

196-0 
161-1 
238-7 


Mean. 








105-9 


172-9 


213-3 


206-3 


180-9 


169-0 


194-6 


223-3 


213-6 


197-9 



Table XLIII. 

Excess or defect of the mean electrical tension above 60 div. at each ob- 
servation-hour, as compared with the mean of each winter in the years 1845, 
1846 and 1847, and the mean of the three winters. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. Mean. 


1845. 








111-0 


11-2 


+ 
35-1 


8-0 


49-4 


56-4 


290 


+ 
27-1 


+ 
63-1 


196-0 


1846. 








77-8 


30-7 


+ 
2-1 


+ 
10-8 


16-1 


24-2 


+ 
13-4 


+ 
37-6 


+ 
3-6 


1611 


1847. 








73-7 


32-7 


+ 
9-3 


+ 
22-4 


+ 
18-4 


3-7 


+ 
6-1 


+ 
8-7 


16-9 


238-7 


Mean. 









92-0 


25-0 


+ 
15-4 


+ 
8-4 


170 


28-9 


3-3 


+ 
25-4 


+ 
15-7 


197-9 



There can be no question that a much greater regularity of movement 
characterizes these periods than we found appertaining to those of the entire 
year. In each of them we find the two maxima well-developed ; in the win- 
ter of 1847 the forenoon maximum was the highest, but in other respects they 
agree more or less closely with the aggregate winter curves. The diurnal 
march is well-traced: commencing at 8 a.m., we find the forenoon maximum 
attained at 10 a.m., then a well-marked fall until 4 p.m., the afternoon mini- 
mum, after which a regular and rather rapid rise until 8 p.m., the epoch of 
the evening maximum, which is followed by a diminution of tension at 10 p.m. 
The annexed curves (fig. 10), which may be well compared with those on 
page 143, exhibit .-ill the winter phsenomena of high tension with considerable 
distinctness. It may be remarked, that in 1845 the evening maximum oc- 
curred at 10 p.m., and that a close agreement, in this respect, obtains be- 
tween the high tension and aggregate curves in the winter of 1845. 

In our remarks on the winter curves of aggregate tension (see page 123), we 
noticed the influence which the winter curves exerted on those of the entire 
year, and suggested the probability that the higher tensions materially in- 
fluence the general results. This is very strikingly illustrated by the com- 
parison of the winter curves of high tension with those of the same season as 
deduced from the aggregate observations; the main features of the curves in 
both series are similar, the principal difference consisting in the values of the 



ON ELECTRICAL OBSERVATIONS AT KEW. 



145 



4 A.M. 10 A.M. 



10 P.M. 2 A.M. 



'A 



1847 




maxima in the winter of 1847. We 
see at a glance how greatly the 
forms of the aggregate curves de- 
pend on the higher tensions. On 
comparing the two series with those 
of the entire year (aggregate ten- 
sion), the influence of the high ten- 
sions upon the whole is readily 
traced. We see the winter curves of 
high tension strongly influencing the 
winter curves of aggregate tension, 
and these again the aggregate of the 
entire year, the three series of curves 
closely resembling each other. The 
influence of the high tension entire 
year on the curves of aggregate ten- 
sion for the same period is not so 
striking ; the summer readings mo- 
dify the curves, and illustrate the 
remarks we have already offered on 
the variability of the point of sepa- 
ration. 



Table XLIV. 
'Comparison of the excess or defect from the mean of the diurnal periods of 
winter, as deduced from the aggregate observations and from those above 
60 div. 



Value. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


Aggregate... 
Above60div. 


div. 

77-6 


div. 

78-9 


div. 
^•4 


div. 
55-6 
92-0 


div. 

90 

25-0 


div. 

+ 

27-9 

+ 
15-4 


div. 
+ 

13-7 

+ 
8-4 


div. 

+ 

3-9 
170 


div. 

06 
28-9 


div. 

+ 

27-3 
3-3 


div. 
+ 

55-2 

+ 
25 4 


div. 

+ 

43-4 

+ 
15-7 


div. 
102-1 
197-9 



184.9. 



146 



REPORT — 1849. 



In the above table the correspondence within certain limits as to excess 
and defect, in reference to the mean of each period, is well seen ; also the 
striking development of the forenoon and evening maxima in each case. 
Upon the continuation of the observations of high tension at midnight, 2 and 
4 A.M. in the winter, the mean line would be lowered and the corre.spondence 
rendered more complete. 

Daring the day the movements do not very materially differ from those of 
the aggregate curves for the same periods ; this is evident from the follow- 
ing table : — 

Table XLV. 

Synopsis of the principal points in the aggregate and high tension winter 

curves. 



Forenoon 
Value. Maximum 
above 
Minimum. 


Evening 
Maximum 

above 
Minimum. 


Evening 
Maximum 

above 
Forenoon. 


div. 

Aggregate 28*5 

Above 60 div ^i'S 


div. 

55-8 
54-3 


div. 

27-3 
100 





Diurnal period above 60 div,. Summer. — The 668 readings upon which this 
period is based are thus distributed among the twelve observation-hours: — 

Table XLVI. 

Number of positive I'eadings above 60 div. at each observation-hour in the 
three summers of 184-5, 1846 and 1847. 



Year. 


Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Sums. 


1845. 
1846. 
1847. 







3 
2 
3 


16 
14 
23 


26 
37 
44 


19 
31 
35 


9 
5 
6 


7 
6 
6 


13 
10 
10 


24 
17 
13 


42 
46 
35 


68 
50 

48 


227 
218 
223 


Sums. 






8 


53 


107 


85 


20 


19 


33 


54 


123 


166 


668 



It will be at once apparent that these readings are but unequally distri- 
buted. As in the former instances, the greatest numbers occur about the hours 
of the forenoon and evening maxima ; but the numbers about noon and 2 p.m. 
are so small as to render it questionable whether we should regard the periods 
deduced from the observations as true representatives of natural phaenomena : 
we shall however give them in the same form as the others, and in our re- 
marks solicit particular attention to the maxima occurring in each summer, 
either at noon or 2 p.m. 

Table XLVII. 

Mean electrical tension above 60 div. at each observation-hour in the three 
summers of 1845, 1846 and 1847? with the mean diurnal period of summer. 



Year.iMid. 2 a.m. ,4 a.m. 6 a.m. 

i 1 1 


8 a.m. 10 a.m. Noon. 


2 p.m. 4 p.m. 


6 p.m. 


8 p.m. ilO p.m. Mean. 


1845 

1846.' 

1847.' 


" div. 

85-0 

72-5 

70-8 


div. 
120-7 
141-2 
102-8 


div. div. div. 


div. 
122-1 
181-2 
161-2 


div. 

76-5 
139-7 
79-5 


div. 

731 
105-9 
82-3 


div. 

114-0 

88-7 
88-9 




124-3; 92-8 
104-3 123-3 
89-7 145-8 


72-2 

238-0 

66-7 


130G 110-6 
106-6 113-3 
1260 107-7 


Mean. 


...... 76-6 118-4 


103-1 


125-7 


112-0 


153-2 


96-6 


85-6 


97-4 


122-1 jllO-5 



ON ELECTRICAL OBSERVATIONS AT KEW. 

Table XL VIII. 

Excess or defect of the mean electrical tension above 60 div. 
servation-iiour, as compared with the mean of each summer 
1845, i846 and 1847, and the mean of the three summers. 



147 



at each ob- 
in the years 



Year. Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. 


Noou. 


2 p.m. 

div. 

+ 

11-5 

+ 
67-9 

+ 
53-5 


4 p.m. 
div. 

341 

+ 
26-4 

28-2 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


1845. 
1846. 
1847. 






div. 
25-6 
40-8 
36-9 


div. 

+ 

101 

+ 
27-9 

4-9 


div. 

+ 

13-7 

9-0 

18-0 


div. 

17-8 
+ 

10-0 
+ 

38-1 


div. 

38-4 

+ 
124-7 

41-0 


div. 

37-5 

7-4 

25-4 


div. 

+ 

3-4 

24-6 

__ 

18-8 


div. 

+ 

20-0 

6-7 

+ 

18-3 


div. 

110-6 
113-3 
107-7 






Mean. 






33-9 


+ 
7-9 


7-4 


+ 
15-2 


+ 
1-5 


+ 
42-7 


13-9 


24-9 


13-1 


+ 
11-6 


110-5 







4 A.M. 10 A.M. 

In the annexed curves (fig. 11), 

rC the general irregularity which is 

2 apparent in the tables is very di- 

^°' I stinctly marked. We have already 

•g alluded to the maxima at 2 p.m. 

" or noon ; with one exception they 

S are the highest of each curve ; but 

Z how far, from the small number 

2 of observations that contribute to 

I ri their determination, they can be 
g a regarded as truly representing a 

I I mean increase of the electrical 
^ a tension above 60 div. at this pe- 
,>M riod of the day, must, we appre- 
o| hend, be left for future observa- 

an. g'o tions to determine. It is however 
■I £ likely that even on a long series of 
g ^ years the number of high tensions 
Is at noon and 2 p.m. will always 
jjj, ^ u bear a very small proportion to 
1;;^ those at other hours, especially 
.|'| near the epochs of the forenoon 
^ and evening maxima. In two of 
■s the aggregate summer curves, 
I 1845 and 1847, we have small 
g subordinate maxima at 2 p.m., 
1 which, when compared with the 
an, .2 two principal, are scarcely appa- 
c rent. Nothing of the kind appears 
g in the winter curves, either aggre- 
gate or high tension, so that if the 
4 A.M. 10 A.M. 10 P.M. 2 A.M. maximum about 2 p.m. in summer 

truly represent a natural phaenomenon, it is one peculiar to the summer 
months. The close approximation of the values of the means of each sum- 
mer is an interesting feature, which suggests considerable hesitation in de- 
ciding on the character of these irregular curves. The aggregate and low 
tension summer curves also agree in their means, differing but little from each 
other in value. 

l2 




148 



REPORT 1849. 





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ON ELECTRICAL OBSERVATIONS AT KEW. 



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150 REPORT — 1849. 

la addition to the principal results of the discussion of the aggregate and 
low tensions on pages 138 and 141, we find from that of the high, that the 
movements of the electrical tension above 60 div. in the winter are such as 
strongly to confirm the suggestion of the forenoon and evening maxima re- 
sulting from such high tensions. 

Tables XLIX., L. and LI. exhibit the mean electrical tension above 60 div. 
at each observation-Iiour for each month in the three years 1845, 1846 and 
1847, with the monthly, seasonal and yearly means. — The characters of the 
monthly movements are exhibited to the eye in the sheets of curves illus- 
trating this report. See Plate X. and XL 

Table LII. exhibits the mean monthly electrical tension at each obser- 
vation-hour, deduced from the observations of three months ; also the mean 
summer, winter and yearly tensions, deduced from the observations of three 
summers, winters and years. The last line in tlie table, to which the word 
" Means " is prefixed, exhibits the mean tension in each month, as deduced 
from all the separate monthly observations ; /. e. the mean tension of January, 
'277*1 div., is the result of all the January observations in the three years. 
The same thing holds good of the seasonal and yearly mean tensions. 

The curves projected from these numbers will be found on Plate XI. 

Annual Period. 

Aggregate observations One of the principal results of the foregoing dis- 
cussion has been to exhibitthe march of the electrical tension duringthetwenty- 
four hours constituting the period of a day. This march has been found to 
present two well-defined maxima, in most instances removed from each other 
by an interval of twelve hours, the principal occurring at 10 p.m. and the in- 
ferior at 10 A.M. Two minima have also been ascertained, the principal at 
4 A.M. and the subordinate at 4 p.m. At a particular season of the year, 
there have been indications of a curve ofloio tension presenting considerable 
approximation to a single progression, more or less in harmony with the curve 
of temperature \ but the curve deduced from all the positive observations is 
not in harmony with the curve of temperature, inasmuch as neither of the 
maxima corresponds with either of its turning-points. We must not however 
forget, that the greatest development of electricity, so far as the diurnal 
period is concerned, takes place from sunrise to 10 p.m., and includes the 
period that the sun is above the horizon, and to this extent there is a con- 
nection between the temperature and the electrical tension. We now pro- 
ceed to examine those changes of the electrical tension, the period of which 
is completed in the same time that the earth is occupied in making a revolu- 
tion round the sun. 

The following table contains the number of readings in each month of the 
three yeai's which form the bases on which the results in the succeeding 
tables rest. It will be remarked, that the greatest number occur in the sum- 
mer and the least in winter, the cause of which has been already referred to 
as resulting from the cessation of observations at 6 a.m. during the winter 
mouths. 



ON ELECTRICAL OBSERVATIONS AT KEW. 



Table LIII. 



151 



Number of positive readings in each month of the three years ISiS, 1846 

and 1847. 



Year. 


Jan. Feb. 


Mar. 


AprilJMay. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. Sums. 


1845. 
1846. 
1847. 


287 
264 
244 


258 
228 
226 


228 
276 
278 


280 
259 
271 


305 
308 
313 


299 
308 
300 


330 
327 
320 


313 
314 
315 


318 
316 
318 


287 
269 
298 


220 
280 
265 


249 
250 
255 


3374 
3399 
3403 


Sums. 


795 


712 


782 


810 


926 


907 


977 


942 


952 


854 


765 


754 


10176 



Table LIV. 

Mean electrical tension of each month in the three years 1845, 1846 and 
1847, with the mean annual period, as deduced from the whole. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May.' June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. Mean. 


1845. 
1846. 
1847. 


div. 

109-3 

95-9 

258-8 


div. 

190-3 
100-1 
206-6 


div. 
64-5 
78-9 
79-6 


div. 
56-1 
63-7 
52-2 


div. 1 div. 

38-7 260 
42-8 33-0 
32-3 28-8 


div. 

25-9 
31-3 
59-7 


div. 
29-9 
26-3 
31-9 


div. div. 
37-5 46-2 
27-2 65-6 
34-3 41-0 


div. 
83-9 
49-8 
78-7 


div. 

84-2 

160-3 

84-3 


div. 

63-1 
61-3 
76-3 


Mean. 


150-7 


166-6 


75-0 


57-2 


37-9J 29-3 


38-8 


29-4 


33-0 50-5 69-6 


109-5 


66-9 



Table LV. 

Excess or defect of the mean electrical tension of each month, as compared 
with the mean of the year for the three years 1845, 1846 and 1847, and 
the mean annual period. 



Year. 


Jan. 


Feb. 


Mar.fApril. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct.JNov. 


Dec. 


Mean. 


1845, 


div. 
+ 
46-2 


div. 

+ 

127-2 


div. div. 

+ - 

1-4 70 


div. 
24-4 


div. 
37-1 


div. 
37-2 


div. 

33-2 


div. 
25-6 


div. div. 

- + 

16-9 20-8 


div. 
+ 
21-1 


div. 

63-1 


1846. 


+ 
34-6 


+ j + + 1 - - 
38-8 17-6 2-4 , 18-5 28-3 


30-0 


35-0 


34-1 


+ 1 - 
4-311-5 


+ 
99-0 


61-3 


1847. 


+ 
182-5 


+ + - - - 
130-3 3-3 24-1 |44-0 47-5 


16-6 


44-4 


42-0 


- + 
35-3 2-4 


+ 
8-0 


76-3 


Mean. 


+ 
83-8 


+ + 
99-7 81 


9-7 29-Oi 37-6 

1 


28-1 


37-5 


33-9 


- + 
16-4 2-7 


+ 
42-6 


66-9 



An annual period in the electrical tension is not only very perceptible, but 
unquestionable. It is, with an exception hereafter to be noticed, a single 
progression having its turning-points in February and June. The exception 
alluded to consists in an increase of tension in July ; but as this occurred only 
in one year (1847), it will form the subject of remark further on. From the 
mean of the three years, we find that June and August present nearly the 
same electrical tension, the diiference being only O'l div. In September a 
small rise occurs which is increased in October ; the augmentation becomes 
more rapid from November to January and then receives a check, the Fe- 
bruary increment being less than those of December and January. In 
February the maximum is attained, which is succeeded in March by a very 
rapid diminution of tension which continues through April and May, the 
decrements becoming less in value until June, the month presenting the 
lowest tension. 

From this progression those of individual years differ to a greater or less 



152 



REPORT — 1849. 



extent : the turniug-points do not occur in each year in the same months, and 
y the range of tension differs materially. 

S The year 1847, as we have already 

noticed, presents the highest tensions ; 
this is very apparent from the follow- 
ing table of range. 

1 Table LVI. 

^ Mean annual range of the electrical 

2 tension in the years 1845, 1846 
t and 1847, with the mean annual 
I range of the three. 



bo 



3 years. 



Year. 


Range. 


1845. 
1846. 
1847. 


div. 

164-4 
134-0 
230-0 


Mean. 


137-3 



S The greater development of elec- 
2 tricity in the year 1847 occurred in 
t, the month of January. The annexed 
5 curves (fig. 12) are projected on pre- 
^ cisely the same scale as those of the 
g diurnal periods, and are strictly coni- 
I parable with them. 
~ On contrasting the annual with the 
I diurnal period, we find a marked dif- 
.2 ference which is not of an ordinary 
rean. M character. In the diurnal period we 
"S found an increase of tension towards 
M the forenoon, succeeded by a diminu- 
I tion, the tension still continuing high 
1 in comparison with readings obtained 
c after 10 P.M., at which hour the highest 
g tension was most usually observed. 
g The periods characterized by high and 
low tensions were those at which the 
sun was above and below the horizon 
(speaking in a general sense), the 
"" "' "' development of electricity appearing to 

£ be connected with the increase of tem- 

perature, lu the annual period the reverse of this takes place : that portion of 
the year during which the sun is further removed from the northern temperate 
zone is characterized by the exhibition of electricity of much higher tension 
than that which is observed during the period when he is nearest thereto. 
From the months in which tlie greatest and least tensions occur, it appears 
that there is a connexion between the annual curve of temperature and that 
of the electrical tension, the progression of the latter being to a certain ex- 
tent in harmony witii tiiat of the former, but inverse. It is well known that 
the same characteristic is presented by the annual curve of humidity, which 
is in inverse harmony with the annual curve of temperature, and this at once 



ON ELECTRICAL OBSERVATIONS AT KBW. 



153 



directly connects the annual period of the electrical tension with that of the 
humidity, and strongly confirms the suggestion already offered, that the high 
tensions' at least measure the electrical tension of aqueous vapour. In order 
to illustrate this, the mean annual period of humidity, deduced from five 
years' observations at the Royal Observatory, Greenwich, is placed in con- 
nexion with the annual period of the electrical tension in the following table, 
in which the electrical tension is expressed in entire divisions of Volta's elec- 
trometer No. ], and the humidity in the natural scale, in which complete 
saturation is reckoned as equal to 1000. 

Table LVII. 
Mean annual periods of electrical tension and humidity. 



Period. 


Jan. 


Feb. 


Mar. 


AprU. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


Electric. 
Humid... 


151 
908 


167 
894 


75 
856 


57 38 
821 829 


29 
791 


39 
816 


29 

845 


33 

874 


51 

893 


70 
911 


109 
910 


67 
863 



Table LVIII. 

Comparison of the excess or defect from the mean of the electric and humid 

annual periods. 



Period. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


Electric. 
Humid... 


+ 
84 

+ 
45 


+ 
100 

+ 
31 


+ 
8 

7 


10 
42 


29 
34 


38 
72 


28 
47 


38 
18 


34 

+ 
11 


16 

+ 
30 


+ 
3 

+ 
48 


+ 
42 

+ 
47 


67 
863 



The general correspondence as to the months exhibiting the greatest 

degree of humidity and the greatest 
electrical tension is very percepti- 
ble. It is however to be remarked, 
>. that the maximum of electrical 
i| tension does not occur in the same 
5 month as that of humidity. In 
■g Table LVIII., the later occurrence 
c of the turning-points of the annual 
I period of electricity as compared 
5 with that of humidity is very 
.| striking. 

g In the annexed curves (fig. 13), 

Z the points in which these periods 

;;; correspondas well as those in which 

g they differ are rendered very ap- 

§ parent to the eye. The curve of 

•3 humidity is projected on a scale 

I suitable for comparing it with that 

B of the electrical tension, 100 divi- 

J sions of the natural scale before 

mentioned, or one-tenth of the 

whole, being considered as equal to 

one inch. 





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154 



REPORT — 1849. 



Low tension. — In tlie following table, which exhibits the distribution of 
low readings in each month of the three years, the greater number during the 
summer is very apparent ; it will be remarked that July presents the greatest 
number and February the least; the proportion is nearly as 3 to 1. 

Table LIX. 

Number of positive readings below 60 div. in each month of the three years 

1845, 1846 and 1847. 



Year. 


Jan. Feb. 


Mar. 


April. 


May.' June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. jS urns. 


1845. 
1846. 
1847. 


184 

146 

79 


107 

109 

83 


145 
152 
167 


211 
172 
190 


257 
268 
289 


277 315 
280 306 
291 j 273 


287 
297 
292 


271 

291 
279 


206 
198 
253 


113 
193 
174 


149 2522 

73 2485 

152 2522 


Sums. 


409 j 299 464 


573 


814 \ 848 1 894 


876 


841 


657 


480 


374 7529 



Table LX. 

Mean electrical tension below 60 div. of each month in the three years 1845, 
1846 and 1847, witii the mean annual period, as deduced from all the posi- 
tive readings below 60 div. 



lear. 


Jan. 


Feb. 


Mar. April. 


May. June. 


July. 


Aug. Sept. , Oct. Nov. Dec. Mean. 


1845. 
1846. 

1847. 


div. 
25-8 
34-7 
38-8 


div. 

30-7 
34-6 
36-2 


div. div. 1 div. div. 
28-7 29-0 ' 25-2 21-5 
35-1 31-3 27-5 268 
35-2 35-3 27-4 27-6 


div. div. 
22-5 240 
28-5 22-3 
36-4 28-7 


div. j div. div. div. div. 
27-5 1 25-6 32-4 28-6 25-9 
22-8 33-3 30-7 37-3 288 
28-5 26-2 31-8 35-0 31-1 


Mean. 


31-5 


33-7 


33-l| 31-8 26-81 25-4 


28-8 25-0 


26-2 28-1 31'5' 32-9 28-6 

i 1 1 



Table LXI. 
Excess or defect of the mean electrical tension below 60 div. of each month, 
as compared with the mean of the years for the three years 1845, 1846 
and 1847, and the mean annual period. 



Year. Jan. 


Feb. 


Mar. 


April. May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


1845. 01 


+ 
4-8 


+ 
2-8 


+ 
31 


0-7 


4-4 


3-4 


1-9 


+ 
1-6 


0-3 


+ 
6-5 


+ 
2-7 


25-9 


+ 
1846. 59 


+ 
5-8 


+ 
6-3 


+ 
2-5 


1-3 


20 


0-3 


6-5 


60 


+ 
4-5 


+ 
1-9 


+ 
8-5 


28-8 


1847. 


+ 
7-7 


+ 
5-1 


+ 
4-1 


+ 
4-2 


37 


3-5 


+ 
5-3 


2-4 


2-6 


4-9 


+ 
0-7 


+ 
3-9 


311 


Mean. 


+ 
29 


+ 
61 


+ 
4-5 


+ 
3-2 


1-8 


3-2 


+ 
0-2 


3-6 


2-4 


0-5 


+ 
2-9 


+ 
4-3 


28-6 



In the above tables we see an annual period nearly similar to that deduced 
from the entire series of positive observations during the three years. The 
main feature — tiiat of an increase of electrical tension in the winter and a 
decrease in the summer — is the same in both periods ; and from this circum- 
stance the legitimate inference is, that the low tensions are affected by the 
presence of aqueous vapour as well as the high ; consequently the arbitrary 
division at 60 div. fails at all seasons entirely to separate the electricity of 
aqueous vapour from that of the atmosphere, supposing the true march of 
the latter to be in harmony with tliat of the temperature. There are some 
minor differences between the two periods which it may be interesting to 



ON ELECTRICAL OBSERVATIONS AT KEW. 



155 



'A 



3 years. -(.^ 



Mean. ^ i 



notice here. The progression is not single ; it presents a depression at or 
near the period of the maximum, and an elevation at or near the period of the 
»j minimum. The maximum occurs 

S .S i'l February and the minimum in 

August: commencing with the latter 
month, we have a gradual and un- 
interrupted rise until December of 
7*9 div. ; this is succeeded by a de- 
pression of l*^ div. in January, and 
in February the maximum occurs, 
showing an increase on January of 
2"2 div. The fall is then very gra- 
dual and uninterrupted until June — 
value 8-3 div. The elevation before 
spoken of occurs in July ; it is as 
much as 3"4 div., and is succeeded 
■^M by the minimum of August. The 
S^ annual periods of single years par- 
J-S take of the same irregularity of 
.= S movement which characterizes the 
I 3 « annual periods deduced from all the 
I g positive observations. 
1 The symmetrical position of the 

■§ elevation and depression interrupting 
■3 the general march of the electrical 
■3 tension at July and January, and 
'S their coincidence with the usual 
e turning-points of the annual curve 
§ of temperature, suggest the idea 
I that they may be more or less con- 
i nected with that curve ; i. e. it is not 
I improbable that they may be the 
^ turning-points of the annual curve 
which depicts the annual progression 
of atmospheric electricity as distinguished from that of aqueous vapour, the 
latter being more strongly developed and consequently overpowering the 
former. 

We have among the diurnal curves one that presents a striking similarity 
to that now under consideration ; it is the curve of low tension for the mean 

of the three winters. In our ex- 
^'8' ^5* amination of this curve, we con- 

sidered that its peculiar form arose 
from the tendency in the readings 
to exhibit a single pi-ogression 
which was interrupted by the pre- 
sence of aqueous vapour affecting 
the lower readings. It will be ob- 
served that the two curves (fig. 15), 
although to a great extent possess- 
ing similarity oi form, are strikingly 
in contrast; they are to a great extent the converse of each other. In the 
winter we find the lower tensions struggling to maintain a single progression, 
which is overpowered, not by the maximum being depressed, but by the 
superposition of two maxima in all probability the effects of aqueous vapour, 



Low 
tension." 



156 



REPORT — 1849. 



and it is only after we have examined the yearly and summer curves that 
we find a tendency to a single progression in the winter. In the annual 
curve it is the aqueous vapour that produces the single progression ; this is 
very apparent in the aggregate curves. When however we remove the ten- 
sions that appear more immediately to result from the presence of aqueous 
vapour, this single progression is interrupted at those points at which it is 
probable the influence of the vapour may be less than that of atmospheric 
electricity, and at these points only we have a corresponding elevation and 
depression. From the above considerations, both with regard to the diurnal 
and annual periods, we apprehend that it must be concluded, that a mere 
arbitrary division of the readings at any particular point will fail effectually 
to separate the electrical tension into its constituents, viz. that which is de- 
pendent on the solar action from that which results from the presence of 
aqueous vapour : nevertheless it appears, we apprehend, highly probable that 
the indications of a diurnal as well as an annual progression of atmospheric 
electricity, each having an ascending and descending branch, and consequently 
both being single progressions, are by no means of an uncertain character, 
and that the only requisite is a suitable mode of observation in order to apply 
formula, capable of effecting such a separation, whereby all electrical tensions 
resulting directly from the presence of aqueous vapour may be ascertained and 
deducted from aggregate tensions as measured by the electrometers ; that the 
curves both of atmospheric electricity and the electrical tension of aqueous 
vapour may be exhibited each freed from the influence of the other, so that 
their connexion or non-connexion with other meteorological elements may 
be readily ascertained. 

High tension. — In the following table the great difference between the 
high readings in summer and winter is very apparent : February furnishes 
the greatest number (413) and June the least (59) ; the proportion is exactly 
7 to 1. 

Table LXII. 

Number of positive readings above 60 div. in each month of the three 
years 1845, 1846 and 1847. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Sums. 


1845. 
1846. 
1847. 


103 
118 
165 


151 
119 
143 


83 
124 
111 


69 

87 
81 


48 
40 
24 


22 

28 

9 


15 
21 
47 


26 
17 
23 


47 
25 
39 


81 
71 
45 


107 

87 
91 


100 
177 
103 


852 
914 
881 


Sums. 


386 


413 


318 


237 


112 


59 


83 


66 


111 


197 


285 


380 


2647 



Table LXIII. 

Mean electrical tension above 60 div. of each month in the three years 1845, 
1846 and 1847, with the mean annual period, as deduced from all the 
positive readings above 60 div. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 

138-3 

920 

168-2 


Dec. 


Mean. 


1845. 
1846. 
1847. 


258-5 
171-5 
364-2 


303-5 
160-0 
305-5 


127-1 
132-7 
146-3 


138-8 

127-7 

91-6 


110-8 

145-3 

91-2 


821 
94-6 
68-3 


98-3 

71-3 

194-8 


94-4 
97-6 
72-5 


95-3 

78-4 
76-2 


98-5 
155-7 
124-4 


167-1 
211-0 
156-9 


173-2 
149-7 
205-6 


Mean. 


277-1 


262-8 


136-0 


118-6 


118-9 


85-9 


146-1 


87-6 


84-8 


1250 


133-7 


184-8 


175-9 



[n the 



'A 



1847.- 



3 years.- 



-Mean. 



ON ELECTRICAL OBSERVATIONS AT KEW. I57 

Tables LXII. LXIII. and LXI V. the annual period is very apparent, 
9 but It exhibits a much greater irregu- 

S larity of movement, both in the indivi- 

dual yearsandinthe mean of the three, 
than the annual periodasdeducedfrom 
all the observations. This irregularity 
of movement is well seen in the an- 
nexed curves (fig. 16), as well as the 
character which the high readings 
impart to the aggregate curves ; for 
on comparing these with the aggre- 
gate curves on page 152, it will be 
observed that the latter present all 
the essential features of the curves of 
high tension, but so subdued that 
the movements appear more gentle 
and regular. In fact, throughout the 
series (excepting the summer months) 
tlie curves of high tension materially 
influence those as deduced from all 
the observations, and lead to the con- 
clusion, that either throughout the 
year or during the winter, upon the 
supposition of high readings more 
directly measuring the electrical ten- 
sion of aqueous vapour, the presence 
ot such vapour materially afl^ects the 
results. The same thing holds good 
with regard to the summer curves • 
for although the curves of high ten- 
sion in the summer are very ano- 
malous, yet the difference between 
the summer and winter curves of low 
tension, and the greater similarity 
between the aggregate and low ten- 
sion summer curves, combined with 
the dissimilarity between the aggre- 
gate and low tension winter curves, 
strongly suggest that the summer low' 
tension, as well as the aggregate 
curves, are materially influenced by 
the vapour, from the effects of which, 
as before observed, it is desirable the 
curves exhibiting the diurnal and 
annual march of electricity should be 
freed. 



"Mean. 



-Mean, 



—Mean. — 



158 



REPORT — 1849. 



Table LXIV. 

Excess or defect of the mean electrical tension above 60 div. of each month, 
as compared with the mean of the year for the three years 1845, 1846 and 
1847, and the mean annual period. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


1845.1 85-3 


+ 
130-3 


46-1 


34-4 


62-4 


91-1 


74-9 


78-8 


77-9 


74-7 


34-9 


6-1 


173-2 


1846. 


21-8 


+ 
10-3 


17-0 


220 


4-4 


55-1 


78-4 


521 


71-3 


+ 
60 


57-7 


+ 
61-3 


149-? 


1847. 


+ 
158-6 


+ 
99-9 


59-3 


114-0 


114-4 


137-3 


10-8 


133-1 


129-4 


81-2 


37-4 


48-7 


205-6 


Mean. 


+ 
101-2 


+ 
86-9 


39-9 


57-3 


57-0 


90-0 


29-8 


88-3 


91-1 


50-9 


42-2 


+ 
8-9 


175-9 



Section 2. — Discussion of Observations at Sunrise and Sunset. 

The observations made at sunrise and sunset furnish two series from which 
an interesting comparison with the mean annual period as deduced from 
three years' observations (see p. 151) may be derived. The epochs of obser- 
vation of course are variable, coinciding in the summer with those points of 
the diurnal curve that are situated nearer the two superior turning-points, 
the principal extremes ; while as regards the epochs of winter, that of sunrise 
approaches within two hours of the forenoon maximum, and that of sunset 
nearly coincides with the afternoon minimum. That this variability influ- 
ences, no doubt to a considerable extent, the exhibition of electrical tension 
at the epochs of sunrise and sunset, there can be no question. Upon consulting 
I'able V. (p. 118) it will be seen that the sunrise observations throughout the 
year, with the exception of those just about midwinter, fall in that portion of 
the diurnal curve that is belmo the mean of the whole year ; while those at 
sunset appertain to a portion of the curve above the mean. We are there- 
fore prepared to expect that the sunset observations throughout the year 
should present higher electrical tensions than those at sunrise, and such is the 
general fact — the tension at sunset is with but few exceptions higher than 
that at sunrise. 

The entire number of observations employed in the deduction of the fol- 
lowing results is 3367 ; of these, 1712 were made at sunrise and 1655 at sunset. 
The following tables exhibit the distribution of these observations over the 
respective months of the five years during which they were made, and also 
the mean of each month as based upon these numbers. 

Table LXV. 

Number of positive readings of the electric tension at sunrise in each month 
from August 1843 to July 1848 inclusive. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Sums. 


1843. 
















26 


30 


24 


27 


31 


138 


1844. 


28 28 


27 


30 


31 


30 


30 


28 


24 


28 


28 


31 


343 


1845. 


26 


27 


23 


29 


31 


24 


27 


28 


30 


30 


30 


31 


336 


1846. 


30 


27 


30 


26 


31 


26 


27 


30 


29 


27 


30 


30 


343 


1847. 


31 


27 


31 


28 


30 


24 


29 


29 


30 


31 


29 


'28 


347 


1848. 


31 


29 


28 


30 


31 


28 


28 












205 


Sums. 


146 


138 


139 


143 


154 


132 


]41 141 


143 


140 


144 


151 


1712 



on electrical observations at kew. 
Table LXVI. 



159 



Mean electric tension at sunrise in each month from August 1843 to July 
1848 inclusive, with the mean monthly electric tension deduced from them. 



Year. 


Jan. 


Feb. 


Mar. 


AprU. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 

div. 

480 
43-7 
43-8 
51-3 


1843. 
1844. 
1845. 
1846. 
1847. 
1848. 


div. 

127 
105-3 

99-4 
176-9 

80-9 


div. 

93-9 
933 
673 
92-6 
405 


div. 

23'6 
290 
53-4 
54-8 

88-7 


div. 

42-0 
31-2 
35-5 
43-6 
44-3 


div. 

li'-i 

26-9 
33-9 
19-1 

46-5 


div. 

12-7 
20-2 
19-0 
20-8 
21-3 


div. 

17-3 
162 
24-3 
36-3 
31-2 


div. 
15-7 
25-8 
18-5 
19-3 
22-0 


div. 

26-1 
19-3 
21-9 
210 
22-9 


div. 

17-4 

24-9 

30-5 

32-4 

30-5 


div. 

105-0 
593 
62-3 
33-3 
40-3 


div. 
40-7 

116-5 
692 
81-6 
48-2 


Mean. 


118-3 


77-1 51-0 


39-4 


27-5 18-6 


25-1 


20-3 


22-4 


27-5 


59-3 


71-6 


46-8 



Table LXVII. 

Number of positive readings of the electric tension at sunset in each month 

from August 1843 to July 1848 inclusive. 



Year. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct.'Nov. 


Dec. 


Sums. 


1843. 
















25 


30 


24 


28 


31 


138 


1844. 


27 


25 


27 


29 


30 


29 


28 


28 


25 


27 


27 


30 


332 


1845. 


26 


26 


22 


25 


25 


26 


29 


27 


29 


31 


26 


27 


319 


1846. 


30 


24 


29 


26 


29 


28 


28 


29 


29 


28 


30 


29 


339 


1847. 


29 


27 


29 


26 


27 


26 


30 


27 


29 


30 


30 


29 


339 


1848. 


29 


25 


28 


23 


28 


27 


28 












188 


Sums. 


141 


127 


135 


129 


139 


136 


143 |l36 


142 


140 


141 


146 


1655 



Table LXVIII. 

Mean electric tension at sunset in each month from August 1843 to July 
1848 inclusive, with the mean monthly electric tension deduced from 
them. 



Year. 

1843. 
1844. 
1845. 
1846. 
1847. 
1848. 


Jan. 

div. 

1 731 

90-2 

86-5 

342-2 

158-6 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


div. 

156-5 
151-2 

78 1 
1705 

61-3 


div. 

48"7 
60-6 
162-1 
66-5 
81-7 


div. 

39-3 
61-3 
751 
50-7 
124-1 


div. 

32-1 
435 
41-5 
58-4 
820 


div. 

34-'6 
34-2 
44-0 
37-0 
61-2 


div. 

38-3 
29-8 
46-8 
54-9 
50-0 


div. 

380 
40-1 
43-4 
35-6 
39-4 


div. 
49-2 
46-3 
50-7 
34-4 
42-7 


div. 
44-0 
56-8 
57-2 
72-9 
42-2 


div. 
164-8 
58-6 
74-4 
60-1 
783 


div. 

58-7 
225-0 

84-4 
181-2 

86-3 


div. 

790 
64-6 
76-7 
89-6 


Mean. 


171-2 


124-8 


85-6 


68-2 


51-3 


42-2 


440 


39-3 


44-6 


54-8 


87-1 


127-4 


78-4 



The results of the five years' observations furnish the ordinates of two annual 
curves, viz. that exhibiting the annual period of the electrical tension at sun- 
rise, and that exhibiting its annual period at sunset. As before remarked, 
the sunset curve is superior to that of sunrise. In fig. 17, these curves are 
projected on the same scale, so that the eye at once recognises the monthly 
differences between them. The annual curve, as deduced from the observa- 
tions of 1845, 1846 and 1847, is also added for the sake of comparison. It 
will be observed that the three curves agree in presenting the slight increase 
of tension in July as compared with both June and August, which forms a 
secondary but very inferior maximum, and to which allusion has already been 



160 



REPORT 1849. 



made. The minimum tension at sunset occurs in August (value 39*3 div.), 
and is succeeded in September and October by a gentle and regular increase. 
From October to January the increase is very rapid, but at the same time 
very regular, so that the curve possesses a bold flowing character, the as- 
cending branch being free from interruptions arising from sudden starts in 

Fig. 17. 



S. O. N. D. J. F. M 




Curves representing the annual period of the electrical tension at sunrise, sunset, and the mean from 
the obserrations of 1845, 1846 and 1847. 

the movement, or from sudden and irregular increments of tension. Thei 
apex which occurs in January is well-marked and acuminated in its character* 
and the portion of the descending branch immediately succeeding it is to i 
great extent symmetrical with the corresponding portion of the ascenmni 
branch, and this symmetry obtains at least between the months of Novemoei 
and March. The entire diminution of tension from January to June presents 
precisely the same characteristics as the increase from August to Januarj, 
viz. regularity of decrement, giving to the curve a flowing character, whicn 
in consequence of the large difl'erences in the monthly tensions also possesses 
considerable boldness. e^a.e ic^^onrl 

The mean annual curve derived from the observations of 184-5, l«*b anu 
1847, differs from the curve just examined in two or three minor particulars. 



ON ELECTRICAL OBSERVATIONS AT KEW. 



161 



It is not so gracefully flowing in its character, although based on a greater 
number of observations, thereby indicating a certain irregularity of move- 
ment in the monthly increase and decrease of tension, doubtless dependent 
on the accide7ital electrical character of each individual month contributing 
to the mean, which accidental character, it is highly probable, is derived from 
certain disturbing influences to be noticed in the next section, the effects of 
which have been eliminated in the sunset curve by employing five instead 
of three years' observations. The apex of the mean annual curve of 1845 to 
1847 occurs a month later, but from the high tension in January it would 
probably appear that from a longer series of observations, January and 
February would present an equality of tension, or January would become 
the superior. As it is, there is at this point a marked difference between the 
curves, the later occurrence of the apex in the three years' curve destroying 
to a great extent the symmetry so observable in the sunset curve. With 
the exceptions just noticed, the two curves in their general course are similar, 
and this would suggest that the sunset curve presents to a certain extent an 
approximation to the mean annual curve of electrical tension, but in excess. 
The monthly differences between the two are as follows. 

Table LXIX. 

Monthly differences between the annual periods at sunset (five years) and 
the naean of the years 1845, 1846 and 1847. 



Jan. 


Feb. 


Mar. 


April. 


May. 


June 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


div. 
+ 
20-5 


div. 
41-8 


div. 
+ 
10-6 


div. 

+ 

11-0 


div. 
+ 
13-4 


div. 

+ 

12-9 


div. 
+ 
.5-2 


div. 

+ 

9-9 


div. 

+ 

lJ-6 


div. 

+ 

4-3 


div. 

+ 

17-5 


div. 

+ 

17-9 


div. f 
+ 
11-5 



It will be observed that these differences upon the whole are greater in 
winter than in summer, particularly in the months of November, December 
and January. During these months the epoch of sunset is nearer to 4 p.m. 
than at any other period of the year, and at this hour the electrical tension 
differs only 22 div. from the mean, being in excess. If we take the curve 
of the three years as representing the mean tension, then it would appear 
that the mean tension at sunset increases upon the mean of all the observa- 
tions at the twelve daily readings during the winter as compared with the 
summer, to the extent of about 16 div. The following numbers express the 
ratio of the mean tension derived from the observations at the twelve obser- 
vation-hours to the mean tension at sunset. 

.^Table LXX. 
Ratio of the mean electrical tension, as derived from the observations of 1845, 
1846 and 1847, to the mean electrical tension, as derived from five years' 
observations at sunset for each month in the year. 



Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


•880 


1-334 


•876 


•838 


•738 


•694 


•881 


•748 


•739 


•921 


•799 


•859 


•853 



It will be observed that these ratios approach nearer to unity in the winter 
than in the summer, agreeing in this respect with the differences already 
noticed ; but while the increasing differences denote divergence in the curves, 
the increasing ratios indicate a proportional convergence in the values of 
their ordinates. In winter the proportional value of the entire mean tension, 

1849. M 



162 REPORT — 1849. 

as compared with the sunset mean tension, is nearly two-tenths more than it 
is in summer, i. e. in summer the value of the entire mean tension is about 
seven-tenths of the sunset mean tension, while in winter it is nearer nine- 
tenths: there is a greater jjroportional difference in summer tiian in winter. 
That this ought to obtain is evident from the consideration that the epoch of 
mean tension as before-mentioned is 4 p.m. In the summer the epoch of 
sunset is nearer 8 p.m., at which hour the tension is higher than at 4 p.m., 
consequently the differences of the two sets of mean tension should from this 
variability of the epoch of sunset be greater in summer than in winter; and 
although this is not apparent when we contemplate the differences only, 
because of the great increase of tension in the winter, yet upon ascertaining 
the ratios of the one series to the other it becomes apparent, the proportional 
differences as we have seen being greater in summer than in winter. 

The irregularity of the curve of entire mean tension renders it doubtful 
whether these ratios ought to be regarded as at all sufficiently approximate 
to justify tiieir employment in deducing from a series of sunset observations 
the entire mean tension. The month of July presents its usual anomalous 
character. October also presents a higher tension than the usual flexure of 
the curve would indicate as the mean, and the displacement of the apex 
renders it difficult to apply any correction at present to the February mean ; 
nevertheless it is highly probable that a scale of corrections founded on the 
distance of the epoch of sunset from that of the mean tension of the entire 
year, and applied to the deductions from five or more years* observations, 
would furnish a tolerable approximation to the annual period of the entire 
mean tension. 

The lowest curve in fig. 17 is that derived from the observations at sun- 
rise ; it partakes greatly of the character of the sunset curve, the flowing of 
the ascending branch only being interrupted by a greater increment of 
electrical tension in November than the mean monthly increment at this 
period of the year, and this would appear to be confined to November 1843 
(see Table LXVI. on page 159). With this exception the sunrise curve follows 
the sunset very closely, the principal difference being in range, the range of 
the sunset exceeding that of sunrise by 32'2 div. 

We now come to examine the differences between the annual periods of 
sunrise and sunset. These periods differ from each other not only in value, 
but, as we have just observed, in range ; the consequence is an inequality of 
the monthly differences between them. We have already alluded to the ap- 
proximation of the sunset curve to the mean annual curve derived from the 
observations of three years at the twelve observation-hours, the necessary cor- 
rections being comparatively small ; it is however probable that the curves of 
sunrise and sunset approach much nearer in for7n to the true annual curve, 
which in value would come between them, and it is also likely that both curves 
may furnish true representatives of the annual period when certain corrections 
are applied, the value and range of the sunrise being necessarily lower than 
those of the sunset, from the observations contributing to its determination 
being made at a portion of the day characterized by a. feebler development of 
the electrical tension. As the tension increases towards sunset in a certain ratio 
and according to a certain law which is most probably preserved during the 
annual progression of the electrical tension, the consequence would be that 
■with increasing tensions at sunset we should have increasing differences 
from summer to winter and decreasing differences from winter to summer, 
and that from a sufficiently long series of observations either at sunset, sun- 
rise, or any selected hour, the mean annual period might be deduced. The 
following are the differences between the two series. 



ON ELECTRICAL OBSBEVATIONS AT KEW. 163 

Table LXXI. 
Monthly differences between the annual periods at sunrise and sunset. 



Jan. 
52-9 


Feb. 
47-7 


Mai-. 
34-6 


April. 
28-8 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


23-8 


23-6 


18-9 


19-0 


22-2 


27-3 


27-8 


55-8 


31-6 



It will be remarked that these differences gradually decrease from De- 
cember to July and gradually increase from July to December, but it should 
not be forgotten that the variability of the epochs of sunrise and sunset has 
a great tendency to produce a difference between the mean monthly values 
of the tensions of the two periods in the contrary direction, i. e. a greater 
difference in June and a less difference in December. In the sumnaer, when 
we have the least difference in consequence of the general low tension of the 
season, the epochs of observation are the furthest removed from each other, 
that of sunrise nearly coinciding with or being but little removed froni the 
epoch of the principal minimum, and that of sunset being brought withia 
two hours of the epoch of the principal maximum : under these circumstances, 
and leaving out of consideration the effects of other movements, we ought to 
have the greatest difference between the tensions. On the other hand, in 
winter the epoch of sunrise occurs within two hours of the forenoon maximum, 
and that of sunset nearly coincides with the afternoon minimum ; it is conse- 
quently manifest that the differences existing under these circumstances should 
be the least, and the entire series of monthly differences ought to enter as 
corrections in deducing the true annual period from observations at sunrise and 
sunset. It is however clear, from the series of differences before us, that this . 
object cannot be attained by a mode of discussion which regards them only, the 
two opposite series of differences being mingled together in those presented 
to our notice ; but if we compute the ratios of the sunrise to the sunset mean 
tensions, w^e shall probably discover the effects of the recess and approach of 
the epochs of observation according to the season of the year, the further 
they are removed from each other the lower the ratio — coincidence of value 
being considered as unity — and on the contrary the nearer they approach 
each other the higher the ratio, the proportional difference being less. The 
following numbers clearly exhibit these proportional differences. 

Table LXXII. 

Ratio of the mean electrical tension at sunrise to that at sunset, for each 
month of the year. 



Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


•691 


•618 


•596 


•578 


•536 


•440 


•570 


•517 


•502 


•501 


•680 


•562 


•596 



In these ratios the effect of the variability of the epochs of observation is 
very apparent, the difference between June and January being as much as 
•251, which is more than one-third of the ratio in January. In June the 
mean tension at sunrise is less than one-half of the mean tension at sunset ; 
in January it is considerably more than in June, being very nearly seven- 
tenths of the sunset mean tension. There are two or three anomalies in the 

m2 



164 



REPORT — 1849. 



numbers, apparently arising from the sunrise observations, which must render 
a more extended series necessary before a correct scale of ratios between the 
two series can be computed. 

Section 3. — Discussion of Observations bettoeen August 1, 1843, and 

December 31, 1844. 
The entire number of observations selected from the seventeen months 
constituting the earlier portion of the five years is 1897; of these 551 were 
made in the last five months of 1843, and 1346 in the year 1844. It is quite 
improbable that from a series of this kind an annual period could be deduced. 
The only epochs of observation adopted in 1843 and 1844, and continued 
during the remainder of the five years, were sunrise and sunset ; they ac- 
cordingly, of all the observations, furnish an unbroken series during the 
whole period, and as such have been already examined. The epochs of the 
i-emaining observations, 9 a.m. and 3 p.m., having been discontinued at the 
end of 1844, the results furnished by them are necessarily very partial. In 
the discussion of 1843 and 1844 they have been incorporated with those of 
sunrise and sunset, and have been employed in the first instance in deducing 
the mean tensions in Table LXXIIL, which are those of each day on which 
positive electricity 07ily as a general rule has been observed. 

Table LXXIII. 

Mean electrical tension of each day from August 1, 1843, to December 31, 
1844, on which positive electricity only was observed. 



£;! 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. Sept. 1 


Oct. 


Nov. 


Dec. 




div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


div. 


1 


19-75 


39-25 


14-25 


85-25 


33-75 




111-25 


41-25 


425- 


38-75 


11- 






146-25 


20- 


44-25 


43-12 


2 




29- 


18-50 


425- 


77-50 


154-75 


375- 


42-50 


162-50 


31-25 


30-75 






98-75 


14-37 




63-62 


3 




21-75 


18-25 


59-50 


39-25 


925- 


372-50 


27-50 


66-25 


27-12 


31- 


32- 




30-37 


6-25 




30-62 


4 




14-50 


12-75 


158-75 


8-50 


600- 


107-50 




30-75 


22-75 


21- 




16-37 


19-6'2 


34-12 


49-37 


65-62 


5 18-7S 


34-25 


33-25 


31- 


17-50 


15- 


450- 


76-25 




36-50 


23- 




48-12 


18-37 


3-87 


160-63 


450- 


6 18- 


62-25 




34-75 


42-25 


20-75 


425- 


77-50 


54- 


64-75 


5-25 


21-87 


20-37 


25- 


16-37 


71-25 


800- 


7 2775 


58- 


27- 


22- 


17-25 


100- 




38-75 


68-12 


27-50 


8- 


28-23 


17-37 


30-25 


32-50 


65- 


216-25 


8 2275 


62-50 


18- 


62-75 


50- 


51-25 


55- 


51-66 


73-33 


11- 


25-50 


37-50 


12-50 


52-87 


57-50 




71-25 


9 35-50 


39-25 




158-75 


63-75 


40- 




12-75 


56-25 


21- 


13-25 


25- 


15-75 


29-50 


3-75 


46-87 


35-25 


10 1 5-50 




51-25 


33-50 


22-25 


33-25 


4873 




32-75 


17-50 


15-12 


34-37 


52-50 


45-50 


21-37 


83-75 


50-62 


11 46-25 


13- 




345- 


25- 


52-50 


66-25 




43-50 


30-75 


23- 


24-87 


•29-87 


43-23 


19-75 


58-12 


66-87 


12'l5- 


46-25 




447-50 


168-75 




68-75 




33-87 


23-12 


23-87 


30-50 


■29-87 


32-75 


38-12 


16-5 


76-87 


13 48-75 


62-25 


27-50 


428-75 


225- 




743-75 


42-50 




28-23 


10-50 


17-25 


30-87 


34-12 


27-50 




23-62 


14 24-75 


77-50 


41- 


233-75 


175- 




205- 


40-62 


15-75 


21-50 


10-25 


26- 




33-50 


16-25 


76-25 


55-62 


15 .. 


33- 


51-25 


245- 


28-25 


e's- 


975 


28- 


23-25 


13-50 


14- 


20-62 


20-87 


4-30 




12-50 


195- 


16 .. 


58-75 


27- 


43-75 


17-50 


375- 


61-25 


15-75 


24-75 


21-50 


21-25 


39-62 


41-87 


3-87 


41-66 


22-50 


178-23 


17 51-25 


63-75 


30- 


116-25 


112-50 


300- 


15-50 


6-50 


162-12 


8-75 


29-12 


42-50 


26-87 




33-12 


13- 


575- 


18 66-33 


47-50 


21-2.1 


68-25 


32-50 


38-75 


8-50 


35- 


25-75 


16-75 




30-87 


26-62 


30-87 


39-75 


20-75 


108-75 


19 136-25 


39-25 


107-50 


198-75 


77-50 


42-50 


26-75 


24- 


33-50 


7-50 


16-75 


35-62 


41-87 


60-62 


3812 


37-50 


42-50 


20 


5-75 


61-25 


43-50 




1725 


38- 


36-25 


35-66 


12- 


15-87 


13-25 


16-37 


14-25 




16-75 


37-30 


62-50 


21 


27-25 


55- 




10-75 


13- 


60- 




72-50 


28-25 


15- 


40-37 


32-37 


30- 


15-33 


17-83 


192-30 


57-30 


22 




37-75 


38-75 


53-33 


7-75 


400- 


58-75 


33-75 


21- 


14-75 


25-75 


41-25 


20-62 




39- 


212-30 


160- 


23 


25- 


48-75 


38-50 




20-25 






31- 


38-75 


15- 


49-37 


63-12 35- 






162-50 


68-75 


24 


7-75 


24-25 


20-75 


300- 


20- 


203-75 


37-50 


17-25 


12-50 


16-37 


21-25 


51-6235-87 




55-83 


97-50 


58-73 


25 28-' 


19-25 


43-25 




42-50 


46-25 


53-75 


1-50 


26-75 


16-12 




39-12130-62 


33-50 


45-66 


111-25 


56"25 


26 |20-50 


24-7.'! 


104-75 


18-25 


26-25 


20-25 


30-25 


21-75 


159-50 


15-25 


30- 


12-75 


18-87 


60- 


23-75 


136-25 


375- 


27 [48-75 


15-25 


65- 


26- 


49-50 


42- 


52-50 


13- 


22- 


15-75 


28-75 


16-25 


31-25 


50- 


59-37 


180-62 


650- 


28 . . 


19-75 




23-25 


146-25 


13-25 


59-75 


34-50 


33-12 


8-75 


27-62 


26-62 


52-50 


41-87 


243-75 


109-3- 


183-75 


29 i 3-25 


38-75 


116-25 


33-75 


55- 


28-75 


83-75 


76-23 


38-75 


11- 


31-25 


9-50 


60- 


6-75 


71-25 


41-50 


18-33 


30 !36- 


8-50 




112-50 


201-25 


32-75 




53-12 


45-50 




38- 


21-16 


55-62 


39-37 


66-25 


49-37 


408 12 


31 2875 








b8-76 


■• 




51-50 




19-75 




19-87 


37-50 











From this table has been formed Table LXXIV., which contains the 
greatest and least mean electrical tensions observed in each of the seventeen 
months, with their differences, and the days on which they occurred. 



ON ELECTRICAL OBSERVATIONS AT KEW. 



165 



Table LXXIV. 



Greatest and least mean daily electrical tension in each month, from August 
1843 to December 1844, both inclusive, with their differences, and days of 
the month on which they occurred. 



Month. 


Mean daily electrical 
tension. 


Difference. 


Days of the month on which the 
mean electrical tension was 


1843 and 1844. 


Greatest. 


Least. 


Greatest. 


Least. 




div. 

66-33 

77-50 

116-25 

447-50 

225-00 

925-00 

743-75 

77-50 

425-00 

64-75 

49-37 

63-12 

60-00 

146-25 

243-75 

212-50 

800-00 


div. 

3-25 
8-50 

12-75 

10-75 
7-75 

13-25 
8-50 
1-50 

12-00 
7-50 
5-25 
9-50 

12-50 
3-87 
3-75 

12-50 

18-33 


div. 

63-08 

69-00 

103-50 

436-75 

217-25 

911-75 

735-25 

76-00 

413-00 

57-25 

44-12 

53-62 

47-50 

142-38 

24000 

200-00 

781-66 


18 

14 

29 

12 

13 

3 

13 

6 

1 

6 

23 

23 

29 

1 

28 

22 

6 


29 
30 

4 
21 
22 
28 
18 
25 
20 
19 

6 
29 

8 
16 

9 
15 
29 


September 

October 


November 

December 


February 




May 


June 


July 


August 


September 

October 

November 

December 



The greatest mean daily electrical tension occurred in January 1844, and 
the least in March 1844 : the difference (923'5 div.) is the ranffe of the mean 
tensions during the seventeen months. 

The numbers in this table bear testimony to the same general fact which 
we have already noticed in the discussion of the three years' observations, viz. 
the great increase of electric tension in winter; but from the nature of the 
quantities recorded, they are not comparable with the annual curves deduced 
from the observations of 1845, 1846 and 1847, and from those of sunrise 
and sunset during the five years. 

From Table LXXV. we learn that in every month the electrical tension 
exceeded 79 div. of Volta's electrometer No. 1. In November 1843, Janu- 
ary, February, March, April, and December 1844, the highest observed ten- 
sions at the four observation-epochs were between 1000 div. and 1500 div., 
or between 10° and 15° of Henley's instrument. In the remaining months, 
with the exception of August 1843 and June 1844, the highest tensions 
were between 100 div. and 500 div., or 1° and 5° of Henley, and in the two 
excepted months they were respectively 95 div. and 80 div. The effect of 
the annual progression is very apparent, the higher tensions being confined 
to the winter mouths. 

During the seventeen months the electrical tension was never observed 
below 2 div. of Volta No. 1, except on one or two occasions on which the 
tension was too feeble materially to influence the instrument. The numbers 
in the column of least absolute tensions give the lowest observed tensions by 
Volta's instrument in the respective months. 

Tables LXXVI. and LXXVII. exhibit the monthly distribution of all the 
observations at the four observation epochs, together with the value of the 
mean electrical tension at each observation-epoch in each of the seventeen 
months. 



166 



REPORT — 1849. 



Table LXXV. 

Greatest and least electrical tension observed in each month, from August 
1843 to December IS'i^, both inclusive, with their differences, and the 
days of the month on which they occurred. 



Month. 



1843 and 1844. 



August ... 
September 



October 



November 

December 
January ... 
February. . . 



March. 

April . 
May . 
June . 

July . 



August . . . , 
September . 
October ... 
November 
December 



Absolute electrical ten- 
sion in each month. 



Greatest. 



div. 

95 



115 



300 

1100 

500 
1200 
1000 

1500 

1000 

200 

80 

100 



105 
400 
400 
500 
1100 



Least. 



div. 
2 



Difference. 



div. 

93 



112 



297 



1095 



1497 

997 
198 



95 



101 
397 
398 
496 
1097 



Days of the month on which the 
electrical tension vras 



Greatest. 



Least. 



ri7 9a.m.\ 
1.18 3 p.m./ 



9 a.m 
3 p.m 
7 9 a.m. 
16 9 a.m. 

20 9 a.m. 

21 9 a.m. 

19 9 a.m. 
26 9 a.m. 

12 S.S, 



498 


14 9a.m 


197 


4 9 a.m 


997 


4 9 a.m 



8 9 a.m. 

1 9 a.m. 
■ 5 S.S. 

6 9 a.m. 
" 30 9 a.m. 



23 S.S. 



29 9 a.m. 

1 9 a.m. 
28 S.S. 
27 9 a.m. 

6 3 p.m. 



29 3 p.m. 



30 S.R. 



16 
'23 
= 29 

22 

10 
'17 

18 
■ 9 

17 

25 
"16 

17 

22 
^ 7 

26 
.31 

6 
16 9 

9 3 
16 3 
16 9 



R. 
S. 
R. 
R. 
R. 
R. 

p.m. S.S. 
p.m. 
R. 
R. 
a.m. 

R. 9 a.m. 
R. 

R. 9 a.m. 
R. 
R. 
S. 
R. 
.R. 
S. 
S. 
R. 
R. 
R. 

a.m. S.S. 
p.m. 
p.m. 
a.m. 



Table LXXVI. 

Number of positive readings at each observation-epoch in each month, from 
August IS-tS to December ISM, both inclusive. 



Epochs. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Jan. 


Feb. 


Mar. 


Apr. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 
31 


Sums. 


Suraise . . 


26 


30 


24 


27 


31 


28 


28 


27 


30 


31 


30 


30 


28 


24 


28 


28 


481 


9 a.m. . .. 


26 


30 


24 


28 


31 


26 


28 


27 


29 


31 


30 


30 


28 


25 


29 


28 


30 


480 


3 p.m 


25 


29 


23 


28 


31 


28 


28 


26 


29 


30 


27 


26 


27 


25 


27 


27 


30 


466 


Sunaet . . 


25 


30 


24 


28 


31 


27 


25 


27 


29 


30 


29 


28 


28 


25 


27 


27 


30 


470 


Sums .... 


102 


119 


95 


111 


124 


109 


109 


107 


117 


122 


116 


114 


111 


99 


111 


110 


121 


1897 



ON ELECTRICAL OBSERVATIONS AT KEW. 

Table LXXVII. 



167 



Mean electrical tension at each observation-epoch in each month, from 
August 1843 to December 1844, both inclusive, with the mean annual 
period of 1844. 



Epochs. 


Aug, 


Sept. 


Oct. 


Nov. 


Dec. 


Jan, 


Feb. 


Mar, 


April. 


IVIay, 


June. 


July, 


Aug. 


Sept. 


Oct. 


Nov, 


Dec, 


Mean, 


Sunrise . . 


div, 
157 


div. 
26-1 


div. 

17-4 


div. 
105-0 


div. 
407 


div. 
127'0 


div. 
93-9 


div. 
23-6 


div. 
42-0 


div. 
11-1 


div. 
12-7 


div, 
17-3 


div. 
25-8 


div. 
19'3 


div. 
24-9 


div. 
59-3 


div. 
116-5 


div. 
46-1 


9 a.m. . . . 


34-2 


57-0 


73-9 


188'6 


77-3 


173-1 


189-3 


96-0 


128-4 


30-8 


24-9 


38-6 


38-1 


57-4 


43-3 


138-7 


175-8 


91-5 


3 p.m. .. . 


I8'0 


26-9 


29-5 


86-6 


64' 8 


142-6 


151-5 


35-8 


33-8 


12-0 


18-1 


20-3 


23-8 


35-1 


38-4 


66'l 


204-8 


60-9 


Sunset .. 


38'0 


49'2 


44'0 


l64'8 


587 


173-1 


156-5 


48-7 


39-3 


32-1 


34-6 


38-3 
28-8 


40-1 


46-3 


56-8 


58-6 


225-0 


76-9 


Mean .... 


26-4 


39-9 


41-3 


136'5 


60-4 


153-4 


147-5 


51-2 


607 


21-5 


22-6 


32-0 


39-7 


40-7 


81-0 


180-0 


68-9 



The numbers expressing the mean electrical tension of each month exhibit 
very clearly a mean annual period, which may be advantageously compared 
with the annual periods already deduced; for this purpose the four annual 
periods derived from various sources are included in the following table. 

Table LXXVIII. 

Comparison of the annual periods of the electric tension derived from various 

sources. 



Annual period. 


Jan. 


Feb. 


Mar. 


Apr. 


May. 


June. 


July. 


Aug. 


Sep. 


Oct. 


Nov. 


Dec. 


Mean. 


Sunset, 5 years 

3 years, 1845 to 1847. 

Sunrise, 5 years 

The year 1844 


div. 
171-2 
150-7 
118-3 
153-4 


div. 
124-8 
166-6 

77-1 
147-5 


div. 
85-6 
75-0 
51-0 
51-2 


div. 
68-2 
57-2 
39-4 
60-7 


div. 
51-3 
37-9 
27-5 
21-5 


div. 

42-2 

29-3 

18-6 

22-6 


div. 
440 
38-8 
25-1 

''8-8 


div. 

39-3 
29-4 
20-3 

T'-n 


div. div. 
44-6 '54 8 
33-0 50-5 
22-4 27-5 
39-7 40-7 


div. 
87-1 
69-6 
59-3 
81-0 


div. 
127-4 
109-5 

71-6 
1800 


div. 

78-4 

66-9 

46-8 

71-8 













Upon comparing the annual period deduced from the four daily readings, 
in the year 1844, with those recorded in Table LIV., we find the same irre- 
gularity of movement which characterized each of those deduced from the 
twelve daily readings in 1845, 1846 and 1847. The contrast in this respect 
with the smoothness and regularity in the general flowing of the curves, 
derived from five years' observations, appears to indicate that this is the 
shortest term in which the effects of accidental influences may be efficiently 
eliminated, so as to exhibit the annual progression of the electric tension, 
either in immediate connexion with, or following at some definite interval, 
the annual progression of the humidity of the atmosphere. We have already 
alluded to the protuberance on the upward branch of the sunrise curve, as 
resulting from a higher tension than ordinary in the month of November 
1843 (see p. 162). The fifth column (Nov.) in Table LXXVII. exhibits the 
extraordinary character of this month, and shows that the electric tension 
was developed with increased force at each of the observation-epochs: this 
is very apparent from the comparison of this month with the remaining No- 
vembers, and from it we may infer, that upon five years' observations, the 
tension of November being of the ordinary character, the annual curve is 
likely to present a smooth and gently flowing contour. In the table before 
us the features of the summit of the annual curve are well-marked : we have 
already alluded to the acuminated and symmetrical character of the summit 
of the Bunset curve (see p. 160). This is amply borne out by the annual curve 



X68 REPORT — 1849. 

of the year 18+4, and indeed by the others. Compared with the entire year, 
the three months, December, January and February, present by far the 
greatest electrical tension. In shorter intervals than five years, the months 
of maximum vary, sometimes occurring in the one or the other of the three 
months ; but it appears from the entire series of five years, that the greatest 
tension is confined to the three months above-named. 

The shortness of the period over which the observations at 9 a.m. and 
3 P.M. extend, combined with the irregularity appertaining to the movements 
of a single year, render it impracticable to deduce the relation existing be- 
tween the values at those fixed epochs. Nothing further than the general 
fact, confirmatory of the results deduced from the observations of IS+S to 
1847, viz. that the tension in the forenoon hours is higher than that in the 
afternoon, is likely to be attained. This general result, which is very striking, 
is exhibited in Table LXXIX. 

During the entire period the electric tension increased from sunrise to 
9 A.M. ; the mean value of this increase on the seventeen months is ^S** div. : 
this, however, cannot be considered as of equal importance with the mean of 
the year, because the last five months of the year 184'3 contribute to its de- 
termination. With only one exception, viz. December 1814, the tension de- 
clined from 9 A.M. to 3 p.m. — mean value as before, 30-6 div. It is not to be 
considered that the tension actually AecWnas from 9 to 3, for we have already 
seen that 10 a.m. is the usual epoch of the forenoon maximum, but that the 
tension on an average is lower at 3 p.m. than at 9 a.m. The table shows an 
increase from 3 p.m. to sunset, with two exceptions: December 1843 and 
November 1844, mean value as before, 16-0 div., with the same limitation as 
to the character of the increase, 4 p.m. being the usual epoch of the after- 
noon minimum. These movements are further illustrated by the next table, 
which exhibits the excess or defect of the mean electrical tension above or 
below the mean of each month. 

There are two or three numbers in the above columns that require a 
passing notice ; most of them proceed very regularly, exhibiting a higher 
tension than the mean at 9 a.m. and sunset, and a lower tension at sunrise 
and 3 p.m. The first exception that we have to this order is in December 
1843, the mean tension at 3 p.m. being in excess, while that at sunset is in 
defect. In this month the double progression disappears, the tension de- 
clining 18*6 div. from 9 a.m. to sunset. The second exception occurs in 
February 1844, when the tension at 3 p.m. was 4*0 div. higher than the 
mean ; the usual order of progression was not interrupted ; but from Table 
LXXVIl. it would appear that the increase of tension giving rise to the 
anomaly just noticed, occurred principally between sunrise and 9 a.m., and 
was maintained afterwards. March and April 1844 present similar excep- 
tions to each other in the tension at sunset being below the mean ; the usual 
course of progression was not, however, interrupted in either case, as appears 
from Table LXXVIl. The next exception occurs in November 1844, the 
tension at sunset being 22-4 div. below the mean : an inspection of Table 
LXXVIl. indicates that the increase of tension, as in the former instances, 
took place between sunrise and 9 a.m., hut was not maintained afterwards — 
in fact a diminution instead of an increase occurred at sunset; the increase 
between sunrise and 9 a.m. augmented the value of the monthly mean ten- 
sion, and this, combined with the reversal of the usual movement at sunset, 
occasioned the depression of the mean at sunset below the mean of the 
month. In December 1844 there are no traces of the double progression, 
the tension increasing from sunrise to sunset: the epoch of mean tension for 
the month occurs between 9 a.m. and 3 p.m. ; the signs of these mean quan- 



ON ELECTRICAL OBSERVATIONS AT KEW. 



169 



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170 



REPORT — 1849. 



titles are consequently reversed. It is worthy of remark that, while both the 
Decembers present single progressions, the points of maxima occur at different 
periods of the day. The very close approximation of the values of the means 
of the seventeen months, with opposite signs at sunrise and 9 a.m. and at 
3 P.M. and sunset, is very interesting, and strongly indicates a symmetrical 
disposition of the epochs of mean' tension, as deduced from these four daily 
readings with regard to them. We have, in fact, a tension at 9 a.m. as much 
above the mean as that at sunrise is Ijelow it, and the same thing occurs at 
3 P.M. and sunset, tlie value being rather more than one-third of the move- 
ments in the morning. The great accordance which exists in this respect 
with the results already arrived at is interesting, and tends greatly to confirm 
the deductions that the movements are much greater in the morning and 
forenoon, that the depression in the afternoon is of a minor character, and 
that the principal maximum occurs in the evening ; for although the mean 
tension at sunset is loiver than that at 9 a.m. (see Table LXXVIL), yet the 
occurrence of two winters in the seventeen months tends to place the epoch 
of sunset nearer the afternoon minimum than it is upon the year. It should 
be borne in mind, that as the epochs of sunrise and sunset are variable, those 
of mean tension must be symmetrically disposed with regard to the mean 
epochs of sunrise and sunset, and 9 a. At. and 3 p.m. 

High tensions. — Of the 1346 observations in the year 1844 that contri- 
bute to the results deduced for that year, 180 belong to the class of high 
tensions. The two following tables exhibit the distribution and limits of 
value of these readings. 

Tablk LXXXI. 

Number of positive readings (high, or above 60 div.) at each observation- 
epoch in each month of the year 1844. 



Month. 


Sunrise. 


9 a.m. 


3 p.m. 


Sunset. 


Sums. 


January .... 
February . . 
March .... 

April 

May 

June 

July 

August .... 
September . . 
October . . . . 
November . . 
December . . 


8 

11 

4 

5 

2 

2 

11 

12 


6 
9 
3 
5 
1 

2 

1 

13 

13 


8 
5 

i 

1 

V 

14 


7 
6 

1 

"i 
1 

6 
14 


29 

31 

8 

11 

2 

4 

5 

37 

S3 


Sums 


55 


53 


36 


36 


180 



ON ELECTRICAL OBSERVATIONS AT KEW. 



171 



Table LXXXII. — Limits of value of the high readings at each observation- 
epoch in the year 1844. 



At Sunrise. 

Jan. 
div. div. 

1 at 95. 

5 between 100 and 500 inclusive. 

1 at 800. 

1 at 1000. 

Feb. 
3 at 75. 

3 between 75 and 100. 

5 between 100 and 500 inclusive. 
March. 

4 between 75 and 90 inclusive. 

April. 
4 between 60 and 110 inclusive. 

1 at 500. 

Sept. 

2 between 70 and 75 inclusive. 

Oct. 
2 at 75. 

Nov. 
9 between 65 and 100 inclusive. 
2 between 200 and 300 inclusive. 

Dec. 
4 between 75 and 85 inclusive. 
7 between 200 and 500 inclusive. 
1 at 600. 

55 



At 3 P.M. 
Jan. 

div. div. 

7 between 100 and 500 inclusive. 

1 at 900. 

Feb. 

3 between 200 and 500 inclusive. 



1 at 600. 

1 at 1300. 



1 at 
1 at 



300. 



April. 
Oct, 



300. 



Nov. 



75. 
90. 



1 at 
1 at 

5 between 100 and 300 inclusive. 

Dec. 

3 between 70 and 100 inclusive. 

8 between 200 and 500 inclusive. 

1 at 600. 

1 at 900. 

1 at 1100. 

36 



At 9 A.M. 

Jan. 

div. div. 

4 between 100 and 500 inclusive. 
1 at 1000. 

1 at 1200. 

Feb. 
6 between 120 and 500 inclusive. 

2 at 700. 

1 at 1000. 

March. 

1 at 90. 

1 at 110. 

1 at 1500. 

April. 
4 between 115 and 500 inclusive. 

1 at 1000, 

May. 

1 at 200. 

Sept, 
200. 



1 at 
1 at 



1 at 

2 at 



400, 



Oct. 



200. 



Nov. 



85. 



11 between 100 and 500 inclusive. 
Dec. 

5 between 55 and 95 inclusive, 

6 between 200 and 500 inclusive. 
1 at 700. 

1 at 900, 

53 

At Sunset. 
Jan. 

div. div. 

5 between 100 and 500 inclusive, 

1 at 1000. 

1 at 1100. 

Feb. 
4 between 300 and 500 inclusive. 



1 at 

1 at 

1 at 

1 at 

1 at 



March, 
May. 
Oct. 



600. 
900. 

200, 

200. 

400. 



Nov, 

4 between 50 and 95 inclusive, 

2 at 200. 

Dec. 

3 between 40 and 90 inclusive. 

5 between 100 and 500 inclusive. 

4 at 600. 

1 at 800, 

1 at , 900. 

36 



172 



REPORT 1849. 



Upon consulting Table LXXXII. it will be seen that in most instances 
the months March to October inclusive present tensions considerably lower 
in value than those of the remaining four months, and in connexion with this, 
Table LXXXI. informs us that in June, July and August, all the tensions 
were low. The means have accordingly been taken for January, February, 
the eight months of low tension, November and December; they are exhibited 
in the following table. 

Table LXXXIII. 

Mean electrical tension (high, or above 60 div.) at each observation-epoch 
for the months specified in the year 1844?. 



Epoch. 


Januaiy. 


February. 


Eight 
months. 


November. 


December. 


Mean. 


Sunrise 


div. 
386-9 
616-7 
389-4 
528-6 


div. 
198-6 
480-0 


div. 
108-8 
426-2 


div. 

110-7 
243-8 
137-9 
113-3 


div. 
251-7 
337-3 
375-0 
413-9 


div. 
198-8 
390-4 
361-9 
388-2 




620-0 300-0 
500-0 266-7 


Sunset 




469-3 


406-6 264-3 


163-0 


348-1 ( 325-7 1 










1 



Table LXXXIV. 

Differences between the mean electrical tension (high, or above 60 div.) at 

the four daily epochs for the months specified in the year 1844. 



Epoch. 


January. 


February. 


Eight 
months. 


November. 


December. 


Mean. 


Sunrise to 9 a.m. 
9 a.m. to 3 p.m. 
3 p.m. to sunset. 


div. 

+229-8 
-227-3 
+ 139-2 


div. 

+281-4 
-f. 140-0 
-120-0 


div. 
+317-4 
-126-2 
- 33-3 


div. 
+133-1 
-105-9 
- 24-6 


div. 
+85 6 
+37-7 
+38-9 


div 

+191-6 
- 28-5 
+ 26-3 



Table LXXXV. 
Excess or defect of the mean electrical tension (high, or above 60 div.) at 
each observation-epoch, as compared with the means of the winter months 
and also with the means of the eight months of low tension and of the 
entire year. 



Epoch. 


January. 


February. 


Eight 
months. 


November. 


December. 


Mean. 




div. 

- 82-4 
+ 147-4 

- 79-9 
+ 59-3 


div. 

-2080 
+ 73-4 
+213-4 
+ 93-4 


div. 
-155-5 
+ 161-9 
+ 35-7 
+ 2-4 


div. 

-52-3 
+80-8 
-25-1 
-49-7 


div. 
-96-4 
-10-8 
+26-9 
+65-8 


div. 
-126-9 
+ 64-7 
+ 36-2 
+ 62-5 


9 a.m 

3 p.m 





These tables confirm the general result of the discussion of the high ten- 
sions in 1845, 1846 and 1847, viz. the irregularity of the movements above 
60 div. In the four months specified the quantities are affected by precisely 
the same signs as those in Tables LXXIX. and LXXX., with only one excep- 
tion, and thus we l)ave additional evidence that the higher tensions materially 
influence the aggregate results. 

Loto tensions. — Upon omitting the high readings above specified, we obtain 
a series of numbers considerably in accordance with those recorded in Tables 
XXXIV. XXXV. XXXVI. and XXXVII. 



ON ELKCTRICAL OBSERVATIONS AT KEW. 



173 



The following table exhibits the distribution of the low readings in the 
year 1844, upon which the mean quantities in Table LXXXVIL are based. 

Table LXXXVI. — Number of positive readings (low tension) at each obser- 
vation-epoch in each month of the year 1844. 



Epoch. 


Jan. 


Feb. 


Mar. 


April. 


May. 
31 


June. 
30 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Sums. 


Sunrise.. 


20 


17 


23 


25 


30 


28 


22 


26 


17 


19 


288 


9 a.m.... 


20 


19 


24 


24 


30 


30 


30 


28 


23 


28 


15 


17 


288 


3 p.m — 


20 


23 


26 


28 


30 


27 


26 


27 


25 


26 


20 


16 


294 


Sunset .. 


20 


19 


26 


29 


29 


29 


28 


28 


25 


26 


21 


16 


296 


Sums ... 


80 


78 


99 


106 


120 


116 


114 


111 


95 


106 


73 


68 


1166 



The numbers in this table are perfectly in accordance with those entering 
into the discussion of the low tensions of 1845, 1846 and 1847, in exhibiting 
the greatest quantity in the summer months. 

Table LXXXVIL 
Mean electrical tension (low, or below 60 div.) at each observation-epoch in 
each month of the year 1844, with the monthly and yearly mean tensions. 



Epoch. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


Sunrise . 
9 a.m.... 
3p.m.... 
Sunset . . 


div. 
23-0 
40-1 
43-9 

48-7 


div. 

26-1 

51-6 

49-6 

480 


div. 

13-8 
37-2 
35-8 
42-9 


div. 

18-4 

54-5 

24-3 

39-3 


div. 
Ill 
23-2 
120 
26-3 


div. 
12-7 
24-9 
18-1 
34-6 


div. 

17-3 
38-5 
20-8 
38-3 


div. 
25-8 
38-1 
23 8 
401 


div. 

14-5 

37-7 

351 

463 


div. 
210 
37-7 
28-3 
43-6 


div. 

26-1 
47-5 
40-9 
42-9 


div. 

311 
52-4 
55-9 
59-7 


div. 

19-2 

38-9 

30-6 

41-4 


Means... 


38-9 


44-6 


32-9 


33-9 


18-5 


22-6 


28-8 


320 


335 


32-7 


39-4 


49 


32-6 



Table LXXXVIIL — Differences between the mean electrical tension (low, 
or below 60 div.) at the four daily epochs in each month of the year 1844. 



Epoch. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


S.R. to 9 a.m.... 
9 a.m. to 3 p.m.. 
3 p.m. to S.S. ... 


div. 

+ 

17-1 

+ 

3-8 

+ 
4-8 


div. 

+ 
25-5 

20 

1-6 


div. 

+ 

23-4 

1-4 

+ 
7-1 


div. 

+ 

36-1 

30-2 
+ 
15-0 


div 

+ 

12-1 

11-2 

+ 
14-3 


div. 

+ 

12-2 

6-8 

+ 
16-5 


div. 

+ 

21-2 

17-7 

+ 
17-5 


div. 

+ 

12-3 

14-3 

+ 

16-3 


div. 

+ 
23-2 

2-6 

+ 
11-2 


div. 

+ 

16-7 

9-4 

+ 

15-3 


div. 

+ 

21-4 

6-6 

+ 
2-0 


div. 

+ 

21-3 

+ 
3-5 

+ 
3-8 


div. 

+ 

19-7 

8-3 

+ 
10-8 



Table LXXXIX. — Excess or defect of the mean electrical tension (low, or 
below 60 div.) at each observation-epoch, as compared with the mean of 
each month and also with the mean of the year. 



Epoch. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


July. 


Aug. 


Sept. 


Oct. 


Nov. 


Dec. 


Mean. 


Sunrise . 
9 a.m.... 
3 p.m.... 
Sunset.. 


div. 

15-9 

+ 
1-2 

+ 
5-0 
+ 
9-8 


div. 

18-5 
+ 
7-0 

+ 
50 

+ 
3-4 


div. 

19-1 

+ 
4-3 

+ 
29 

+ 
100 


div. 

15-5 

+ 
20-6 

9-6 

-f- 
5-4 


div. 

7-4 

+ 
4-7 

6-5 

+ 
7-8 


div. 

9-9 
+ 
2-3 

4-5 

+ 

12-0 


div. 

11-5 

+ 
9-7 

8-0 
+ 
9-5 


div. 

6-2 

+ 
61 

8-2 
+ 
8-1 


div. 

19-0 

+ 
4-2 

+ 

1-6 

+ 

12-8 


div. 

11-7 

+ 
5-0 

4.4 

+ 
10-9 


div. 

13-3 

+ 
8-1 

-f- 
1-5 

+ 
3-5 


div. 

17-9 

+ 
3-4 
4- 
6-9 
+ 
10-7 


div. 

13-4 

+ 
6-3 

20 

+ 
8-8 



174 



REPORT — 1849. 



The double progression as a general rule is very apparent in the above 
tables. To the increase of tension from sunrise until 9 a.m. there are no 
exceptions ; two only to the diminution of tension between 9 a.m. and 3 p.m., 
and one only to the increase from 3 v.m. to sunset. The numbers are greatly 
in harmony at least in this respect with the results obtained from the discus- 
sion of the low tensions in the years 184-5, 1846 and 1847. 

The exceptions to the double progression occurring as they do in the winter 
months, viz. January max. at sunset, February max. at 9 a.m., and December 
max. at sunset, are not without significance. In the discussion of the lovv 
tensions in the years 1845, 1846 and 1847, we adverted to the tendency ex- 
hibited by the winter curves to present a single progression ; and while we 
noticed that the essential features of the double progression as exhibited in 
the aggregate curves were compressed as it were into the low tensions in the 
summer months, Ave also remarked that when the higher tensions — which 
were evidently more intimately connected with aqueous vapour, and were 
very much more numerous in the winter, — were withdrawn, the features of 
the double progression were withdrawn also, and suggested that upon a mode 
of directly observing the electrical tension of the aqueous vapour being 
devised, it might probably be practicable to separate it from the aggregate 
tension, and thus obtain a curve of a single progression representing the 
march of atmospheric electricity. The tables before us are strikingly confir- 
matory of the results obtained from the three years' observations. We see 
here, as there, the double progression most decided in the summer months ; 
and the great tendency to a single progression in the winter is quite as con- 
spicuous, if not more so than in those years. Upon the whole, the discussion 
of these seventeen months very strongly confirms the results already obtained. 

One point only remains for our consideration ; it is the annual period as ex- 
hibited by these numbers. It may probably be useful to particularize the 
annual period of each observation-epoch, and with this view the excess or 
defect as compared with the mean annual value of each epoch is given in the 
following table. 



Table XC. 

Excess or defect of the mean electrical tension (low, or below 60 div.) of 
each month in the year 1844, as compared with the mean annual value at 
each observation-epoch ; also the excess or defect of the monthly mean 
tensions, as compared with the mean of the year. 





Sunrise. 


9 A.M. 


3 P.M. 


Sunset. 


Mean. 




div. 


div. 


div. 


div. 


div. 


January .... 


+ 3-8 


+ 1-2 


+ 13-3 


+ 7-3 


+ 6-3 


February . . 


-H 6-9 


+ 12-7 


+ 19-0 


+ 6-6 


+ 12-0 


March .... 


- 5-4 


- 1-7 


+ 5-2 


+ 1-5 


-1- 0-3 


April 


_ 0-8 


+ 15-6 


- 6-3 


— 2-1 


+ 1-3 


May 


- 8-1 


-15-7 


-18-6 


-15-1 


-14-1 


June 


- 6-5 


-14-0 


-12-5 


- 6-8 


— 10-0 


July 


- 1-9 


- 0-4 


- 9-8 


- 3-1 


— 3-8 


August .... 


+ 6-6 


— 0-8 


- 6-8 


- 1-3 


- 0-6 


September . . 


- 4-7 


- 1-2 


+ 4-5 


+ 4-9 


+ 0-9 


October .... 


-f 1-8 


- 1-2 


- 2-3 


+ 2-2 


+ 0-1 


November . . 


+ 6-9 


+ 8-6 


+ 10-3 


+ 1-5 


+ 6-8 


December . . 


-t.11-9 


+ 13-5 


+ 25-3 


-M8-S 


-I-16-4 



ON ELECTRICAL OBSERVATIONS AT KEW. 



175 



In this table the depression of the summer readings below and elevation 
of the winter readings above the mean line at each epoch are very apparent. 
The differences however between the annual periods at each epoch and their 
approach to, or departure from, the mean is rendered more perceptible to the 
eye by the annexed curves (fig. 18). 

Fig. 18. 




J. A. S. O. 

Curves exhibiting the annual periods of the electrical tension (low) at the four observation- 
epochs for the year 1844. 

It will be apparent from these curves that the forenoon and afternoon 
movements upon the annual period are strikingly different. There is con- 
siderable agreement between the curves of sunrise and 9 a.m., and also 
between those of 3 p.m. and sunset ; the four curves forming two pairs, each 
pair presenting many features in common. The greatest difference between 
the curves is noticed at 9 a.m. and 3 p.m. There is more accordance between 
the sunrise and sunset curves, the principal difference occurring in the opposite 
movements in September. The sunrise curve is evidently modified by the 
movements at 9 a.m., as is that of sunset by the movements at 3 p.m. From 
this we may probably infer that the movements in the middle of the day, at 
least between 9 a.m. and 3 p.m., are much more irregular even in the low 
tensions than at any other period. The range (see Table XCL), which is 
lowest at sunrise, increases rapidly between 9 a.m. and 3 p.m. the maximum ; 
and this circumstance, taken in connexion with the cloudiness of the atmo- 
sphere (a subject to which we shall have occasion particularly to refer when 
treating on negative electricity), strongly indicates that the irregularity of 
movement in the middle of the day is more or less connected with the dis- 



176 



REPORT — 1849. 



turbing influences of clouds. The curve of cloudiness, as deduced from six 
years' observations at Green wicli, will be found on page 198. The approxi- 
mation towards agreement in the sunrise and sunset curve is greatly in ac- 
cordance with the phaenomena already noticed in the same curves from five 
years' observations (see page 162); and the differences observable between 
those for the year 1844 strongly confirm the remark that has been offered, 
viz. that a series of five years' observations at least is necessary to eliminate 
the effects of irregular movements. It may be remarked, in immediate con- 
nexion with the curves of 1844, that the sunrise curve is much more in ac- 
cordance with the sunset than that at 9 a.m. is with that at 3 p.m. 

Table XCI. 

Annual range of the electrical tension at the four observation-epochs in the 

year 1844. 



Epoch. 


Range. 


Sunrise. . . . 

9 a.m 

3 p.m 

Sunset .... 


div. 

20-0 

31-3 

43-9 

33-4 


Mean 


30-5 



Part II.— NEGATIVE ELECTRICITY. 

The exhibition of negative electricity being confined within very narrow 
limits as compared with that of positive — the number of readings being ex- 
tremely few — renders it exceedingly doubtful whether we can at all hope to 
find anything like a diurnal period manifested by it. The number of read- 
ings in the three years 1845 to 1847 amounted to 324, and it is not difficult 
to obtain the mean reading at each observation-hour from these records. 
In the seventeen months prior to 1845, great care was manifested in ob- 
serving every and even the minutest change in the kind of electricity with 
which the conductor was charged. Not a shower appears to have occurred 
but it was minutely watched, the rapidity and extent of the changes assidu- 
ously observed, and the length of the sparks carefully measured ; the whole 
being accompanied by notices of the weather at the time which appear to 
possess great accuracy of detail. As however the extremes of the charges 
are usually set down in some cases at the times they occurred, in others in a 
more general manner and between certain epochs, and not at such regular in- 
tervals, except on certain occasions, as would be useful in discussing them with 
a view to determine a diurnal period; such discussion, with regard to the nega- 
tive observations previous to 1845, has not been attempted; but they have 
been carefully arranged in Table XCII. under the heads of " Limits of "Time," 
" Extremes of Charge," " Maximum Length of Spark," and accompanying 
" Weather and Remarks." Under the last head are included the state of the 
weather with remarks by the observer at Kew ; the clouds or other phaeno- 
mena (likely to illustrate the Kew observations) recorded at or near the 
same epochs at the Royal Observatory, Greenwich, and occasional remarks 
by the writer. All remarks having reference to the Greenwich Observatory 
are placed within brackets. 



Q,X ELECTRICAL OBSERVATIONS AT KEW. 177 

In the succeeding table, the great majority of instances in which negative 
electricity has been exhibited, are characterized by hvo very interesting 
features. At Kew one of these features has been t\\e.faUi7}gofrain, in most 
instances heavy ; and the other the great probability, from the almost con- 
stant record, at or near the same epochs at the Royal Observafory, Green- 
wich, of cirro-stratus, and occasionally cumulo-strafus, that these clouds 
have more or less not only accompanied, but contributed their quota to, 
the development of the electricity observed. On numerous occasions, cz'rro- 
stratus has been observed at Greenwich without the electrical instruments 
having been affected, and from this we may with great truth infer that cirro- 
stratus in its ordinary action does Kot occasion a disturbance of the regular 
diurnal march of the electrical tension. Most probably it is onl}' when the 
conditions exist for the precipitation of rain, especially when the rain is 
formed very rapidly and in great quantities, that the electrical condition of 
the cloud is disturbed, and the conductor affected negatively. From the 
great constancy of the phsenomena during a period of seventeen months, we 
are inclined to consider that to a certain extent they illustrate the remark 
relative to the production of lightning by ruin, which occurs in the Report of 
the Committee of Physics, including Meteorology, approved by the Presi- 
dent and Council of the Royal Society, pages 46 and 47. In speaking of 
thunder-storms, the writer, in alluding to one point to which the Committee 
wished some attention to be paid, says, — " It is the sudden gush of rain which 
is almost sure to succeed a violent detonation immediately over-head. Is this 
rain a cause or a consequence of the electric discharge ? Opinion would seem 
to lean to the latter side, or rather, Ave are not aware that the former has 
been maintained or even suggested ; yet it is very defensible. In the sudden 
agglomeration of many minute and feebly electrified globules into one rain- 
drop, the quantity of electricity is increased in a greater proportion than the 
surface over which (according to the laws of electric distribution) it is spread. 
Its tension therefore is increased, and may attain \he point when it is capable 
of separating from the drop to seek the surface of the cloud, or of the newly 
formed descending body of rain, whicli under such circumstances, and with 
electricity of such a tension, may be regarded as a conducting medium. 
Arrived at this surface, the tension for the same reason becomes enormous, 
and a flash escapes." In immediate reference to this remark, we apprehend 
the observations do not so much indicate the actual electric tensio7i of the rain 
fulling on the conductor, as the eftect on the conductor of the electric disturb- 
ance occasioned by the production of the rain ; this disturbance principally 
influencing the cloud from which the rain is precipitated, and through the 
cloud influencing the earth and bodies in its immediate neighbourhood. We 
shall have occasion again to refer to this subject in the Notes that are sub- 
joined. 

The exceptions to the general fact of heavy rain falling when the con- 
ductor has been negatively electrified are rare ; only ten instances are re- 
corded during the seventeen months ; they are given in Table XCIII. p. 185 ; 
some of them are extremely interesting, and are calculated to throw great 
light on the subject to which we have just alluded : we shall notice them in 
their proper places in the Notes that follow. 



1849. 



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ON ELECTRICAL OBSERVATIONS AT KEW. 



185 



Table XCIII. — Instances of negative electricity without rain. 



Date. 



Observed limits of time. 



Observed extremes of charge. 



Max. length of 
spark. 



1843 and 1844. 
Sept. 10. 
Oct. 12. 
Nov. 24. 
July 2. 

„ 6. 

„ 12. 

» 18. 
Aug. 8. 
Sept. 5. 

„ 17. 



h 


m 




2 


10 


p.m. 


1 


15 


p.m. 





30 


p.m. 


Sunset. 1 


4 





p.m. 


1 


35 


p.m. 


6 


20 


p.m. 


1 


26 


p.m. 


10 





a.m. 


?, 





p.m. 



2 47 p.m. 
2 45 p.m. 

1 30 p.m. 

5 p.m. 

2 p.m. 

6 30 p.m. 



4 p.m. 



40°P. 



3^N. 



45"N. 
N. 

6=N. 
]5^N. 
lO'N. 

N*. 
50-N. 
SO-N. 

5-N. 

5"N. 



0-400 



0-500 



* Charge high. 
Notes on Table XCII. 

(*) August'^, 1843. — This thunder-storm was observed at Greenwich: 
cumulo-stratus and scud were registered there at 3** 20™ p.m. with occasional 
showers, soon after which the sicy assumed a very stormy appearance, more 
particularly in the N. and N.W. ; at S** 45™ p.m. a low muttering of distant 
thunder was heard from dark clouds in the N.W., and thunder has been 
heard at intervals to the present time, 5^ 20™ p.m. : at 4*^ 40™ p.m. rain began 
to fall, and it has continued : at 4" 0™ p.m. a fine double rainbow was visible 
in the E.N.E., and at 5^ 20™ p.m. another very perfect one, also double in 
the E. : at present, 5^ 20™ p.m., a large clear break is near the horizon in 
the W., and it is the only part of the sky which is not covered with a dense 
cirro-stratus. At 1^ 20™ large loose fragments of scud were passing from 
the S.W., the portions of the sky without cloud being remarkably clear; the 
rain which commenced at 4^* 40™ p.m. ceased at 5^ 30™ p.m. ; the last clap 
of thunder was heard at 5^ 35™ ; it proceeded from dark clouds in the E. : 
no lightning teas seen during the whole time. The galvanometer was affected, 
the needle moving towards A. 

C*) August \5, 1843. — The thunder-storm was observed at Greenwich. 
At 2)^ 20™ P.M. cumuli and cu7nulo-strafi were seen ; weather hazy. At 
5^ 20™ P.M. the same clouds were registered, and the observer thus writes : 
" Deep mutterings of thunder are heard, proceeding from dark cumulo-strati 
towards the N.E. : the weather is unusually sultry for this time of the day ; 
temperature now at its maximum." At 7*^ 20™ " massive cumulo-strati and 
nimbi in all directions : at Ft^ 40™ p.m. a loud clap of thunder was heard from 
the S.E., and from that time to 6** 10™ p.m. a constant succession of claps 
took place ; no lightning was seen : between 5^ 5C™ p.m. and 6*^ 5™ p.m. the 
rain fell very heavily : distant thunder has been heard to the present time." 
" At 9** 20™ overcast : at 7*^ 40™ a vivid flash of lightning was seen in the 
N.E. which was followed by many others, chiefly forked, and accompanied 
by a heavy rolling of thunder, all from the N.E. : at present distant thunder 
is heard, and occasionally faint flashes of lightning from the N.W. : during 
the time the storm was in the N.E. the zenith was clear." Between 
5i> 4,2"° P.M. and 6*^ 12"" p.m., the galvanometer was affected; maximum de- 
viation towards A 50" at 5^ 49™ 3*, and towards B 65° at the same time. 
This, the greatest oscillation, occurred on the occasion of a loud clap of 



186 REPORT — 1849. 

thunder ; numerous other oscillations occurred with thunder, and rain falling 
in torrents. 

('^) September 10, ISIS. — We have here a well-marked instance of the re- 
gular diurnal march being interrupted by the passage of a cloud in the im- 
mediate neighbourhood ol" the observatory. No rain appears to have fallen, 
yet the instruments were thrown into a state of oscillation, positive to negative, 
which gradually diminislied as the cloud passed off; a spark or sparks O'^ inch 
in length were registered. This cloud appears to have been a cmnulo-straUcs ; 
for at Greenwich at 3 p.m. cumulo-slratus is registered, and during the suc- 
ceeding twenty minutes a very heavy shoicc'r of rain accompanied with thunder 
is recorded. The electrical instruments were not affected. 

C^) October 2, IB^S. — The connexion in this instance between the heavy 
rain and nerjative charge is very apparent, and would, combined with the 
observation of September 10, greatly tend to refer the production of the 
charge to the particular cloud by the agency of which the rain was precipi- 
tated, rather than to the rain itself. Cirro-stratus was registered at Green- 
wich from 9** 20°^ a.m. to 5^ 20"* p.m. The violent squall of rain occurred 
there at 5 minutes before 1 1 a.m. 

(^) October 12, 184-3. — " Front sunrise until about 11 a.m. dull and cloudy. 
At about 11 A.M. a heavy rain began and continued until about 1*" 15" p.m. 
At its commencement Volta stood at 25'^ pos.: immediately afterwards the 
charge became negative, the maximum of whicii was 30° of Henley, and a 
negative state continued until about 2** 45"" p.m. The positive charge then 
remained during the rest of the day. The negative state existed about 

I hour and 30 minutes after the rain had ceased; and the weather during 
this period was fine and accompanied with sunshine. The duration of the 
negative stale of the conductor, viz. about 3 houi-s 45 minutes, from about 

II A.M. to 2** 45™ P.M., one hour and a half of which time elapsed without 
rain, is I believe a rare occurrence, and one which I do not recollect to have 
observed in my former experiments. — [F. 11.]" 

The negative state of the conductor during the tliree half-hours is remark- 
able. It appears the sun was shining and the weather fine; but the register 
does not inform us whether clouds were present or not. On turning to the 
Greenwich observations we find rain recorded at 11'' 20™ a.m., and at 1'' 20™ 
P.M. thin rain falling ; the rain appears to have ceased earlier than this at 
Kew. From O*" 20™ a.m. until "i^ 20™ p.m. cirro-stratus was registered at 
Greenwich ; and as this cloud frequently manifests itself in the form of a 
thin hut very extensive stratum, it is not unlikely that it was the source of the 
negative charge observed. — [W. R. B.] 

(f) October 28, 1843 At 'o^ 20™ p.m. this squall was observed at Green- 
wich w?^//02/< the hail. The observer thus writes: "At present there is a 
violent squall: the rain is falling in large drops: the sky is covered with a 
nimbus: a few minutes since a cumulo-stratus with coloured edges was in 
the west, and scud was passing quickly from the west with a fine blue sky 
between." The head of the galvanometer needle deviated towards A 5°. 

(6) JamiarySl, 1844. — The electrical phsenomena of this day being parti- 
cularly interesting, and well-marked both at Kew and Greenwich, we cannot 
do better than present the reader with the records at both observatories. 

Kew. 

First Storm. — At sunrise fine, but cloudy. At 8'' 45™ a.m. a heavy storm 
of snow and hail began, when Volta stood at 35''"'* pos. The charge im- 
mediately changed to neg., in the maximum of which charge the Henley 
vibrated above 90°, and a stream of fire one inch long flowed from the con- 



ON ELECTRICAL OBSERVATIONS AT KEW. 187 

ductor to the discharger for at least four or five minutes during the time that 
the storm was at its height. At about 9 the storm had ceased, when the 
charge returned to pos. maximum 45° of Henley. 

Second Storm — At noon another storm of snow and hail began, when 
Volta stood at 105"^^'" pos.; but the charge immediately changed to neg., 
and the Henley again vibrated above 90°, sparks 1^ inch. The positive 
maximum was about 50° of Henley, sparks -^^ inch. 

Third Storm. — At l"^ 40"" p.m. a third heavy shower consisting of rain and 
hail began, when Volta stood at lO'^'^* pos., but the charge immediately 
changed to neg., when the Henley vibrated between 60° and 90°, sparks y'g- 
inch. The positive maximum during this shower was about 60° of Henley. 
At 2 P.M. very stormy with heavy rain. At 3 p.m. dull and cloudy. At 
4 P.M. heavy snow. From sunset to 10 p.m. dull and cloudj'. 

Greenwich. 

First Storm. — At the nearest observation, Jan. 30*^ 22^ (Gottingen 9*^ 20™ 
A.M. Greenwich time), the observer records : " A few clouds only here and 
there : at 8** 5™ a.m. rain and sleet began falling ; and about 8*^ 40"^ a.m. snow 
fell thickly, soon covering the ground ; it ceased about 9^ 20™, when the 
clouds broke : wind in gusts to 2, with prolonged lulls." Negative electricity 
was observed between 7 and 9 a.m. very weak. Wind N.W., force |- to 7 lbs., 
rain falling occasionally. 

Second Storm.— Jan. 31<* 0^ Gottingen 1 i^^ 20"" A.^r. Greenwich. Cirro- 
stratus and scud ; wind in heavy gusts to 2|- and 3. At 11'^ 30"" a.m. sparks 
occurred from 005 inch to 0"13 inch in length, 2 in a second. Wind N.W., 
force 12 lbs. At this time a sudden squall of hail, wind and rain occurred ; 
in an instant the gold leaf of the dry pile apparatus was destroyed, and in 
removing it the observer received a severe shock. 

Third Storm. — At l^ 20*" p.m. Greenwich time. Cirro-stratus ; wind in 
heavy gusts ; squalls of hail and snow are frequent ; occasionally, also, a kw 
breaks occur: very dark and gloomy; snow mingled with sleet has again 
begun to fall. Wind N.W., force to 5 lbs. No electricity appears to have 
been observed. 

Between 6 and 9 i'.m. negative electricity was observed at Greenwich. 
Wind W.N.W., force to 2 lbs. Sleet occasionally falling in small quanti- 
ties : strong gusts of wind. 

C*) February 9, 1844 — Cirro-stratus was registered at Greenwich from 
gh 2om pjj tQ ^h 20™ A.M. of the following morning ; two snow-showers oc- 
curred during this period, one at 11 p.m., the other at 4'' 10"" a.m., the 
electrometer-bell ringing during their continuance. Electrical observations 
were made between the undermentioned times : 

d h m h m in. 

Feb. 9 10 55 to 11 35 p.m. max. tension 50 Volta (2) neg., sparks 0*10 
„ 9 11 40 „ 11 54 p.m. „ „ 50 „ (1) „ „ O'lO 

„ 10 4 10 „ 4 26 A.M. „ „ 50 „ (1) „ „ 0-10 

(') February 26, 1844. — We have in the case before us another instance 
(see Sept. 10, 1843) of the electrometers being affected by the approach of 
a cumulo- stratus, and on the present occasion previous to the falling of rain. 
It would appear from the ordinary meteorological observations at Greenwicii 
that the few drops of rain recorded in the electrometer observations at 
jh la^p.M. were succeeded by a heavy squall of rain, which commenced at 
|h jgm p^jyj, anj continued 10 minutes ; the negative charge continued until 



188 REPORT— 1849. 

I'' 55"" P.M. It is worthy of remark, that the approach of the cloud to the 
zenith, the formation of the heavy ruin-drops, and the affection of the instru- 
ments, the charge being negative, loere apparently simultaneous, and succeeded 
by the sudden gusts of rain constituting the heavy squall. 

C') May 18, IS^'i. — The contrast between the observations at Kew and 
Greenwich is interesting: it furnishes us with another instance (and perhaps 
the most striking of the three) of the affections of the instruments by the prox- 
imity of cloud, most probably cirro-stratus, which was prevalent at Green- 
wich, at least before noon. During the changes that occurretl there in the 
electrical charges, small quantities of sleet only fell, and these not in any de- 
gree measurable, for we find on May 18, 22 hours Gottingen time, the same 
records of the rain-gauges as on May 17, 22 hours; but at Kew the period 
marked by the affections of the instruments at Greenwich is characterized by 
three showers, two of which are recorded as heavy, the electrical changes 
being considerable. It is to be remarked, that at Greenwich the tension was 
higher than had been observed previously in the course of the year. These 
phaenomena appear to point to a common origin of the electricity noticed at 
the two observatories, viz. the presence of a particular kind of cloud. It 
cannot in this instance at least be immediately connected with the rain, for 
although the changes loere manifested at Kew during the continuance of the 
showers, yet electricity of a greater tension than any that had been observed 
during the former part of the year teas recorded at Greenwich ; the saine ac- 
tion teas going on at Greentvicli without the rain us at Kew with it: the only 
difference appears to have been, the absence at Greenwich of those particular 
conditions necessary to the production of the sudden gush of rain most fre- 
quently characterizing the exhibition of negative electricity, or rather the 
oscillation of the electrical condition between positive and negative. The 
instance before us presents a very instructive comparison with the passage of 
the cloud over the Kew Observatory on September 10, 1843, when the con- 
ditions for the production of rain did not appear to have existed at Kew, 
while they did at Greenwich ; yet the electrical instruments at Kew were 
affected, while those at Greenwich ivere not. 

(') June 10, ISii. — The records of this shower at both observatories were 
as under : — 

Kew. 

Previous to the fall of any rain upon the conductor, the Henley rose to 
90° pos., sparks l-i-| inch*. At one time of this high positive charge (before 
the rain), the Leyden jar, of about 56 square inches coating, on being applied 
to the conductor, became charged to the intensity of the rod in about 20 
seconds. The charge changed to negative shortly after the rain began, max. 
55° of the Henley, sparks ^^ inch. These high signs lasted about a quarter 
of an hour, and spirtings occurred from the little ball above the discharger. 
The negative charge remained a considerable time after the rain had ceased, 
gradually diminishing. 

Nothing remarkable in the appearance of the clouds ; they were rather 
fleecy or plumose, and not low, but large. 

* These were the longest sparks which we have yet observed ; bat on the 31st of January 
the continuous stream of fire from the conductor to the discharger was much more lasting. 
If the ball attached to the conductor and above the discharger were placed nearer or at the 
end of the cross-arm, the sparks would be longer ; also if it were smaller. But it is, I fear, 
in vain to attempt to measure these very high tensions accurately by ordinary electrometers 
and dischargers. Our Henley was in this instance evidently useless. The shock of the 
spark reached the elbow without a jar. [Observer at Kew.] 



ON ELECTRICAL OBSERVATIONS AT KEW. 189 



GREE^fWICH. 

June 10'' 2"^ Gottingen time, I*' 20™ Greenwich time. Cumuli, cumulo- 
strati, and dark scud ; within the last three minutes the temperature has fallen 
3°, the reading just before the observation having been 74'°*5, and there was 
a sudden exhibition of negative electricity ; a large dark cloud was at the 
time passing over from the N.W.: at 1"^ 27" p.m. a fine shower of rain began 
falling ; at l^^ 29™ the temperature was 62°-0; and at I'' 46™ it was 59°'5. 

Negative electricity recorded between I'' 16™ and l''^^™ p.m., max. tension 
20° Volta (2). Wind W., force to 1 lb., rain falling. 

By means of these records we obtain a further insight into the conditions 
necessary for the exhibition of the phsenomena detailed. Cloud being the 
origin of the electrical oscillations, appears very evident from the affections 
of the instruments at Kew previous to (he fall of any rain upon the conductor ; 
and the very high charge communicated to the conductor under these cir- 
cumstances is highlj' instructive. The usual march of the electrical tension 
was evidently disturbed by the approach of the cloud, although it exhibited 
nothing remarkable. This disturbance did not manifest itself at Greenwich 
until the cessation of the rain at Kew. It appears that at this time the ob- 
server at Greenwich noticed a large dark cloud passing over from the north- 
west, which was attended by two very remarkable phagnomena: — a sudden 
diminution of temperature, with as sudden an exhibitio7i of negative electricity. 
This appears to have occurred at least seven minutes before the fall of any rain. 
The presence of the cloud, the diminution of temperature, and the exhibi- 
tion of negative electricity, appear to be closely and intimately connected, 
and to indicate either that the cloud itself underwent a remarkable physical 
change, which materially influenced bodies in its vicinity ; or, which is the 
most probable, that it existed in such a condition as to produce great physical 
changes in such bodies, so far as electricity is concerned. It is easy to con- 
ceive, that if by any means the temperature of the cloud should be diminished ; 
by coming into a colder portion of air, for instance, a sudden agglomeration 
of its vapour-particles might take place ; its electrical Condition be suddenly 
and extensively disturbed by the enormous tension which these newly formed 
rain-drops might acquire in consequence of the rapidity of their formation, 
in some cases the diminution of temperature being so great as actually to 
freeze them and thus produce hail, which at some seasons is not an unfrequent 
phsenomenon accompanying the exhibitions of negative electricity. The 
electrical influence of the cloud thus circumstanced may not be confined to 
the mere strip of country over which the rain or hail may fall, but may ex- 
tend to some little distance beyond its circumference, and thus the signs may 
be changed without the actual fall of rain in such localities, or the negative 
state continue after the precipitating portion has left the place of observa- 
tion. Nor does it follow that rain must necessarily fall from every portion 
of the under-surface of a cloud; there may be an axis characterized by the 
lowest temperature; around this may exist a zone having a higher tempera- 
ture, and another still higher, the skirts exhibiting the highest. 

It is well known that in showery weather the masses of cumulus present 
the appearance of highly heaped or vastly piled-up clouds towering high in 
the atmosphere, and on many occasions these cumular bodies are surmounted 
by sheets of cirro-stratus, through which their summits frequentlj"^ penetrate, 
giving rise to that modification of cloud termed by meteorologists cumulo- 
stratus. By carefully noticing their mode of formation the idea will be sug- 
gested of vapour rising from the earth by evaporation with considerable force. 



190 REPORT— 1849. 

and which upon passing the vapour-plane is immediately condensed. The 
supply continuing from below, and the condensation going on above, produce 
the heaping, piling-up, and general outline of the cloud — which is particularly 
characterized by its crenated edges, and to which it owes its picturesque ap- 
pearance — just as steam, which, issuing in an invisible state from the funnel 
of a locomotive, meets with a stratum of air sufficiently cold to condense it 
rajiidly, by which it assumes in a very decided manner the characters of the 
highly-heaped cumular clouds. It has been suggested, that the immense 
masses of these clouds, so commonly met with in the calm latitudes between 
the trades, may possess some sucii an arrangement as above-mentioned — at 
least in the temperature of the rain that falls from them — by their more 
elevcded portions being precipitated by tlie colder air with which they come 
in contact ; and as it is likely the most elevated part of the cloud would 
most probably be situated near its centre, the precipitated rain would fall 
along the axis, and bring with it to a greater or less extent the temperature 
which contributed to its formation. The other portions of the cloud not 
being so elevated as the central would produce rain of a higher temperature, 
the rain falling from the skirts of the cloud being the warmest. 

One such cloud appears to have come under the writer's notice, at least if 
the differejice in {he precipitations may be regarded as indicating differences 
of temperature, or of elevation of certain portions of the cloud. The cloud 
was considered to extend over a diameter of about six miles ; near the axis a 
fall of snoiv occurred which was sin-rounded by a precipitation of kail, and 
from the portions near the shirts, rain i'ell. It would appear that the tempe- 
rature in the centre or axis was sufficiently low, or that the summit of the 
cloud was sufficiently elevated to freeze the vapour -particles before they had 
run into drops in the usual manner in which snow is formed ; but in the 
zone characterized by the fall of hail, a different process appears to have 
contributed to its production. Upon the first formation of the drops, the 
temperature appears to have been above the freezing-point, and it is possible 
that the relative diminution of temperature in this zone might have been 
greater than in either the axis or skirts. If so, we have all the conditions for 
a vei'y rapid formation of rain-drops, which, from their proximity to the snow 
on the one hand, and the continued diminution of temperature on the other, 
might soon become frozen. There can be no question but that so rapid a 
conversion of aqueous vapour from tlie aeriform to the solid state, must have 
been accompanied by electrical phsenomena more or less striking ; the elec- 
trical condition of the cloud itself, as before observed, must have been mate- 
rially influenced, and this as it travelled onwards again influenced bodies in 
its more immediate neighbourhood as it passed them. In the observations 
more immediately before us, as well as in numerous others, we find that 
shortly after the lain began the charge became negative. That the cloud 
disturbed the usual electrical condition of the conductor is veiy evident from 
the observations, and it is to be presumed that, at the time the high positive 
charge was communicated to the conductor, tJie heavy rain was falling, 
although it had not arrived at the observatory ; — in other words, that portion 
of the cloud in which the diminution of temperature was so great as to occa- 
sion the rapid formation of rain, and thus alter the electrical condition of the 
cloud itself, was yet at some distance from the observatory. There might pos- 
sibly have been at this moment tivo bodies reciprocally acting on each otiier 
electrically — the body of falling rain and the cloud ; and it may not be at all 
improbable that it is the actions of these bodies, the one on the other, that 
influence our conductors, and give rise to the sudden and extensive changes 
often recorded on the occurrence of squalls of rain, hail and snow. The di- 



ON ELECTRICAL OBSERVATIONS AT KEW. 



191 



minution of temperature in the present instance" at Greenwich was 15° in 
26 minutes, but nothing further tlian the fall of a fine shower of rain 
occurred ; probably the path of the /leav?/ rain did not cross the Greenwich 
Observatory, although the instruments there were influenced. 

(■") June 18, 1844. — This thunder-storm, which exhibited very interesting 
phtenomena at Kew, did not extend eastward so far as Greenwich ; neither 
thunder, lightning, rain, nor any affections of the electrical instruments were 
observed there ; the only record at all bearing on the subject is one that in- 
dicates the presence of cirro-stratus. During the whole time the sky was 
"ompletely overcast at Greenwich. As illustrating the rapid succession of 
plisenomena on these occasions, as well as some of the suggestions in the 
preceding note, it may not be uninteresting to subjoin the entire record of 
the observations at Kew. 

Table XCIV. 

Phaenomena of a Thunder-storm observed at Kew on June 18th, 1844.'. 



Time. 



h m 

3 40 p.m.= 
3 45 p.m. 
3 46 p.m. 

3 55 p.m. 

4 p.m. 
4 2 p.m. 
4 4 p.m. 
4 8 p.m. 
4 10 p.m. 
4 13 p.m. 
4 15 p.m. 
4 21 p.m. 
4 24 p.m. 
4 27 p.m. 
4 34 p.m. 
4 35 p.m. 
4 47 p.m. 

4 51 p.m. 

5 p.m. 
5 4 p.m. 
5 15 p.m. 
5 30 p.m. 
5 37 p.m. 
5 50 p.m. 



Rain begimiing 



Distant thunder 

Distant thunder 

A flash 

Distant thunder; no rain 

Distant thunder; no rain 

A few drops of rain 

A flasht 

AflashJ 

Distant thunder ; a little rain . . 

A flash 

Rain increasing 

Heavy rain 

Heavy rain 

Sudden fall and gradual rise of elec 

Heavy rain 

Heavy rain 

Heavy rain and distant thunder 

No rain 

No rain 

No rain 

No rain 



Henley 22 P 

Henley 40 P 

Henley 50 P 

Henley 25 P 

Henley 5 N 

Henley GO N. (a). 
Henlev65 P. (i). 

Henlev 60 N 

Henley 59 N 

Henley (e). 
Henley 60 N. {d) 
Charge gradually fa 
No effect on electro 

Volta 10 P 

Henlev 35 P. (e)... 

Henley 40 P 

trometer. 

Volta 7 N 

Henley 5 N 

Henley 20 N. (/). 

Henley 17 N 

Henley 15 N 

Volta 90 N 

Volta 6P •.. 



Spark. 



0-300 
0-400 



lling-. 
meter. 



0-300 
0-350 



S. 

S. 

S. 
S.S.E. 
S.S.E. 
S.S.E. 

S. 

s. 



s.s.w. 
s. 
s. 



s.s.w. 
s.s.w. 

S.E. 

S.E. 
S.E. 
S.E. 



The following notes by the writer of this report may probably assist in 
more distinctly particularizing the principal features of the above-recorded 
phaenomena. The references are in letters of the italic alphabet. 

(a) The occurrence of the flash and the increase of the negative tension 
may indicate the approach of the cloud as well as the formation of rain. It 
would appear that from 'S^ 40" to this time, 22 minutes, rain had been falling, 
but not such as to lead the observer to record it as heavy. 

(J) The maximum tension ; rain had ceased, but great oscillation of the 
charges existed. 

(c) This flash appeared to exert a momentary influence on the conductor; 
the tension was slightly declining, but increased after its occurrence. 

* At 3"^ 35™ P.M. distant thunder and lightning, Volta at 50° pes. Distant thunder was 
heard at 3 p.m. 
t Henley fell from 55° to 20°, and quickly rose again. 
% No effect on the electrometer. 



192 REPORT— 1849. 

(d) This flash appeared to have no effect on the electrometer. 

(e) The " gush oF rain" arrived at the observatorj\ It may be remarked 
that after this, tiiunder was heard but once, and in ail the records it is de- 
scribed as distant. From the time thunder was last heard, 4'' 21™ p.m., the 
charge had gradually fallen to Volta 10 div. P. The highest tensions were ob- 
served, not when the rain was heaviest, but when the discharges (at a distance) 
took place more frequently. It is probable that after the cessation of these 
discharges the " gusli of rain" came travelling on, being still accompanied by 
the causes of its production, and a corresponding oscillation of the tension 
occurred. 

(f) The increase of tension on the occurrence of the discharge is very 
apparent, as well as the gradual decline afterwards, notwithstanding the ces- 
sation of rain which occurred within the next 11 minutes. 



(") July 1, 1844. — As the records of this storm have already appeared 
in the volume of Reports for 1844, page 134, we shall not further introduce 
them to the reader. On a careful consideration of the record it will be found 
that the storm may very naturally be divided into three sections, viz. the 
period of heavy rain previous to the electrical discharges ; the period of the 
discharges themselves ; and the period of rain succeeding the discharges, a 
portion of which was heavy. The times are as follows : — first period S^ 30"" 
P.M. to 5^ 55"^ P.M. inclusive=25 minutes ; second period 5^ 56™ p.m. to 
gh y^m p_]^j_ inclusive = 29 minutes; third period 6** 25™ p.m. to 7'^ 50™ p.m. 
inclusive = l hour 26 minutes. We have in the first period a decided instance 
of heavy rain, characterized on one occasion as very heavy, being in advance of 
the actual thunder-storm. During the second period nf^'iihev thunder nor heavy 
rain, except on one occasion, appear to have been noted : it is however to be 
pi'esumed, as we shall have occasion hereafter to notice, that from the fre- 
quency and character of the flashes they were accompanied by both, and the 
probaljility is, that during the exhibition of the lightning the rain that fell 
was much heavier than that in either the preceding or succeeding period. 
In the third period the heavy rain continued about half an hour. The values 
of the tensions having reference to these periods are interesting. The mean 
of the tensions recoided during the first, without having regard to kind, is 
32° of Henley ; that of the second 48° of Henley ; and that of the third 27° 
of Henley, or during the heavy rain only, 33° of Henley. The connexion 
between the high tensions and the electrical discharges from the cloud is 
very apparent ; also the mean values of the tensions during each period of 
the heavy rain indicate a certain relation between them. The entire phae- 
nomena strongly suggest the existence of an axis characterized by the active 
development of strong electric action ; the tension of the cloud and probably 
that of the rain being so enormous that frequent discharges took place to 
restore the equilibrium. This axis occupied about half an hour in passing 
the oVjservatory. It is probable the strong action going on in the centre 
was communicated to a zone of nearly the same breadth in all its parts, in 
which the principal phgenomenon was the rapid formation of rain unaccom- 
panied by electric discharges. In connexion with this it may be remarked 
that the third period may be subdivided into two, the first characterized by 
heavy and the last by light rain ; the duration of the first was, as we have 
already noticed, 30 minutes, namely from 6** 25™ p.m. to 6^ 55"^ p.m. inclusive, 
and this may probably be regarded as the true termination of the storm. 
The three periods, — viz. preceding heavy rain; actual thunder-storm; and 
succeeding heavy rain — do not differ very considerably in duration from each 
other. The first = 25 minutes, the second =29 minutes, and the third = 30 



ON ELECTRICAL OBSERVATION'S AT KEW. 193 

minutes. It is also to be remarked, that at the commencement and termi- 
nation of the second, oscillations in the kitid of tension occurred, the tension 
at the occurrence of the first flash being positive 60° of Henley, and that 
at the last also positive 50*^ of Henley: the intermediate tensions were negative. 
Oscillations also occurred during the periods of heavy rain. 

At Greenwich the same storm was observed, the clouds recorded being 
cirro-stratus and scud. It appears to have commenced at 5^ 49" p.m., at 
least so far as the affection of the instruments is concerned ; the record is as 
follows: — [" This storm first rose in the N.W. ; it then passed round to the 
north, and afterwards to the east, as also did the wind ; at 5"°^ 50™ there was 
a vivid flash of lightning, followed by thunder at the interval of seven 
seconds ; at 5^ 55^ there was another very bright flash, and thunder followed 
at an interval of two seconds ; this was a long peal, the crackling continuing 
from 45^ to 59^ Several flashes of lightning took place between 6^ and 
6^ iS^, followed by thunder at intervals of one, two and three seconds. 
Between 6^ and &^ 20"", 0*78 inch of rain fell at Mr, Glaisher's residence ; 
after this time the lightning ceased ; the rain however continued, but not so 
heavily." — G.] 

From this record it may be gathered that the first flash of lightning oc- 
curred at 5'^ 50™ P.M., being six minutes earlier than the occurrence of the 
first flash at Kew ; it is described as very vivid, and followed by thunder at 
the interval of seven seconds. The second flash, which was very bright, 
occurred at 5^ 55°" p.m., one minute earlier than the first at Kew ; it was 
evidently much nearer than the first observed at Greenwich, the interval 
being two seconds. Between &^ and &" 15™ p.m. several flashes are recorded, 
the point of discharge being upon the whole nearest to the observatory 
during this quarter of an hour. During the same period six flashes were 
registered at Kew, from four of which sparks were obtained, the longest 
being 0*4 inch ; it occurred at 6^ 5™ p.m. This quarter of an hour was evi- 
dently the period in which the focus of the storm passed both observatories, 
and during the twenty minutes between 6^ and 6** 20™ Mr. Glaisher registered 
078 inch of rain at Blackheath. It is this circumstance to which we wish 
to refer in connexion with the axis of the storm, it being evidently accom- 
panied at Blackheath by a great precipitation of rain. Less rain appears to 
have fallen at Greenwich, about half an inch having been registered during 
the twenty-four hours from 9'^ 20™ a.m. of July 1 to 9** 20™ a,m, of July 2^ 
During the storm changes of tension occurred, the maximum tension being 30° 
of Henley and the longest spark 0"23 inch. 

(°) Julys, 1844. — Between ll** 18™ a.m. and I'' 15™ p.m. a thunder-shower 
passed over the observatory at Greenwich. Positive and negative electricity 
were exhibited ; heavy cumulo-strati covered the sky until 1 1'* 55^ a.m., when 
heavy rain began to fall and thunder was heard in the N.W. ; max. tension 
10° of Henley ; sparks max. length O'lS inch. During this time the weather 
at Kew is registered " fine but cloudy," but at l'' to I'' 5™ p.m. a heavy 
shower of rain is recorded, which does not appear materially to have aflPected 
•the instruments. 

Between 4^ 0™ p.m. and 4*" 46™ p.m. changes are again recorded at Green- 
wich with rain falling; the electricity was negative until 4'' 12™ p.m., when 
it suddenly became positive, max. tension observed 120 div. Volta (2). Du- 
ring the whole of this time the charge was negative at Kew. 

(P) August 8, 1844. — There can be but little doubt that the fine rain at a 

distance observed at Kew at l'^ 26™ p.m. is the same shower that fell at 

Greenwich at l** 35™ p.m. ; the only link in the chain of evidence required to 

identify it is the direction in which the fine rain was seen from Kew ; both 

1849. o 



194 REPORT — 1849. 

conductors were affected almost simultaneously. If the shower seen at Kew 
and the one that fell at Greenwich be the same, we have another instance of 
the cloud being the common origin of the electricity exhibited at the two 
observatories*. 



It has already been remarked, that one of the most prominent results of the 
arrangement constituting Table XCII. is the almost constant accompaniment 
of rain in a falling state when the conductor exhibits a negative charge, 
and it is to be particularly noticed that this is in striking contrast with the 
condition of the atmosphere surrounding the conductor when high charges of 
positive electricity are exhibited, the tension 7iot being in a state of oscillation. 
In both cases the conductor may be said to be surrounded by moisture, but 
the conditions of this moisture are extremely different. In the case of high 
positive tension such as we have described, the moisture is not in the liquid 
state ; and even if it may be said to be in contact with the surface of the con- 
ductor, yet it has not passed beyond the form in which it exists as cloud ; the 
conductor under sitch circumstances may be considered as penetrating the 
cloud; and bringing to us the electricity of the cloud itself. In the case of 
falling rain, the conductor is situated beloiv the cloud, the drops impinge on 
it, and it is evidently a matter of question Avhether its indications are those 
of the electricity of the rain, or of a state induced in the conductor by the 
proximity of the cloud. A note aj)pended to the description of instruments 
at Kew (Report 1844', page 124), relative to Henley's electrometer, appears 
to lead to the conclusion that the latter is the case: — " The oscillations of 
the index between the 30th and 35th degrees, sometimes during a heavy 
shower, plainly show that the electricity of the conductor is washed off", as it 
were, as fast as brought." By the electricity of the conductor being washed 
off, as it were, it would appear that the electric state induced in the con- 
ductor was momentarily conveyed yro»« it by the falling rain. In connexion 
with this, we must bear in mind that all rain is not accompanied by negative 
electricity, nor on the other hand is the negative charge o/tt'oys accompanied 
by rain. In those instances in which negative electricity has been observed 
without rain, the state of the weather is printed in italics in Table XCII., and 
in such cases the presence of cloud alone has been the accompanying phae- 
nomenon at the Kew Observatory ; nevertheless on some of these occasions 
heavy rain has fallen at Greenwich. If therefore negative electricity should 
be, as it appears to be, connected with cloudiness, it ought to present a 

* It is a remarkable circumstance and one demanding further attention, tliat most of the 
thunder-storms recorded in the foregoing pages passed more or less to the north-west of the 
Royal Observatory at Greenwich. We give the following as illustrative of this remark: — 

August 4, 1843 N. and N.W. I August 15, 1843 N.E., S.E., N.W. 

June 10, 1844 N.W. July 1, 1844 N.W., N., E. 

July 5, 1844 N.W. j 

To these instances we may add that of the remarkable thunder-storm which passed over 
Loudon on July 26, 1849. In the meteorological observations furnished by the Astronomer 
Royal, and published in the weekly report of the Registrar- General, it is thus noticed: — 
" From l"" till l*" p.m. a violent thunder-storm, chiefly situated to the north ; the flashes of 
lightning were vivid and in quick succession, followed by loud thunder at intervals of 15 to 
20 seconds generally." The storm passed over London from S.W. to N.E., striking several 
buildings in its passage. During the continuance of the storm at Greenwich the electrical 
tension was strongly positive for a period of two hours and a half, viz. from 1'' to S*" 30™ while 
the storm raged in London ; at other times, the observer writes, the tension was strongly ne- 
gative, with frequent constant volleys of sparks and galvanic currents. 

From the above it may be inferred that London is more particularly exposed to the effects 
of thunder-storms, most of them passing over the immediate neighbourhood of the metro» 
polls. 



ON ELECTRICAL OBSERVATIONS AT KEW. 



195 



diurnal period more or less in harmony with it. We have already remarked, 
that the record of negative exhibitions does not furnish us with sufficient 
data previous to 1845'to determine the diurnal period ; nevertheless a synop- 
tical arrangement of the hours included in the entries under the head " Limits 
of Time," furnishes us with an approximation to such a period — at least so far 
as the time of occurrence of negative charges is concerned'. The following 
table, which is deduced immediately from Table XCII., exhibits the number 
of times negative charges (more or less) were observed between August 1843 
and December 1844, both inclusive, between the hours specified, making in 
the whole 231. 

Table XCV. 

Number of readings of negative electricity between the hours specified, 
from August 1843 to December 1844. 



Between 1 


' 














8 






















' 


a 

C3 


a 

a 


S 


S 


a 

d 
<-> 


s 


a 
§ 


p. 
=8 


S 

d. 


2 


a 


a 


a 

si. 


a 
p. 


a 

p. 


a 

p- 


a 

d. 
o 






to 


o. 


00 


CTl 




^ 


•a 


a 


IS) 


« 


'3> 


in 


!0 


t^ 


00 


Ol 




^ 


a 

3 


■a 


o8 


^ 


=S 


•a 


o 


■a 


=3 


=a 


=8 


=3 


•^ 


=8 


•a 


=8 


.o 


to 


!>. 


00 


CTl 




'-' 


■^ 


^ 


Ol 


CO 


^ 


ifS 


to 


t^ 


00 


CJ 




(» 


1 


5 


9 


11 


10 


11 


22 


21 


21 


17 


23 


22 


14 


12 


13 


10 


7 


2 


231 



It appears from this table that during the seventeen months negative elec- 
tricity was not observed earlier than 5 a.m. : at the commencement of the 
series the numbers are small, but they increase gradually until 11 a.m., im- 
mediately after which hour they are doubled as compared with the preceding 
three hours. This value slightly decreases until between 2 and 3 p.m., and 
is again augmented between 3 and 4 p.m. A sudden diminution occurs be- 
tween 5 and 6 p.m. The numbers from 5 p.m. to 8 p.m. are rather higher 
than those from 8 a.m. to 1 1 a.m., and late in the evening they are again 
few as at the commencement. The period of the day between 1 1 a.m. and 
5 P.M. is particularly characterized by the more frequent exhibition of ne- 
gative electricity than either the forenoon or evening, and the ratio as com- 
pared with these periods is very considerable. It is remarkable that so close 
a correspondence as regards the development of negative electricity in the 
middle of the day should obtain in the series of negative readings previous 
to 1845 and during the three succeeding years (see Table III. page 117). It 
is perfectly clear that the greatest number of negative readings occurs about 
the middle of the day, and this of itself would suggest the great probability 
of the existence of a diurnal period in the exhibition of negative electricity. 

Table XCVI. 

Mean amount of cloud at each observation-hour, Gottingen mean time, 
as deduced from the observations of six years at the Royal Observatory, 
Greenwich, and expressed in parts of the natural scale, — a sky completely 
covered with clouds being represented by 100. 



Mid. 


2 a.m. 


4 a.m. 


6 a.m. 8 a.m. 


10 a.m. 


Noon. 


2 p.m. 4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


Mean. 


61 


65 


67 


69 70 


71 


71 


71 69 


66 


62 


60 


«| 



o2 



196 



REPORT — 1849. 

Table XCVII. 



Comparison of the negative readings at Kew previous to 1845, with those 
also at Kew from January 1845 to July 184-8 inclusive, and both with the 
mean amount of cloud at Greenwich from 1841 to 1846 inclusive, at hourly 
and two-hourly intervals. 



A.M. 




P.M. 




M. 


1 


2 


3 


4 


5 

1 
69 


6 

5 
18 


7 

9 

70 


8 

11 

34 


9 
10 
71 


10 

n 

56 


11 

22 
jl 


N. 

21 
46 


1 

21 
71 


52 


3 

23 
69 


4 

22 
55 


5 
14 

36 


6 

12 

60 


7 

13 
62 


8 

10 

38 


9 

7 

60 


10 

2 
33 


11 
61 


Kee. 










Neg.... 
Cloud . 


8 


65 


12 


67 


12 



The numbers in these tables agree, so far as the general fact is concerned, 
in exhibiting a greater quantity of negative readings during a portion of the 
day which is distinguished by a greater prevalence of cloud. Dividing the 
day into two periods, viz. from 8 a.m. to 8 p.m. and from 8 p.m. to 8 a.m., we 
find that the occui-rence of negative electricity is very considerable in the 
day as compared with the night. In the three years 1845 to 1847 (including 
also the first seven months of 1 848), which furnish a comparable scale of num- 
bers with regard to the cloudiness, the proportion of night to day negative 
readings is as 2 to 5 very nearly. The same portion of the day, viz. from 
8 a.m. to 8 p.m., gives, as compared with the remaining twelve hours, the great- 
est prevalence of cloud, the mean amount being about 68 hundredths of the 
whole sky : during the night the mean amount is 65 hundredths, or about 
three hundredths less. In connexion with this, it may be remarked that the 
greater prevalence of cloud is rather in advance of the development of ne- 
gative electricity: the period from 7 a.m. to 7 p.m., and vice versa, gives 
double the diff'erence between the day and night cloudiness ; the mean 
amount in this case for the day being very nearly 7 tenths, while that for the 
night is 64 hundredths, or about 6 hundredths less. The proportion of the 
negative readings is the same. From Table XCII. it may be inferred that 
on most occasions when negative electricity occurred, the sky was entirely 
covered ivith clouds ; and this might suggest that it is not so much the general 
existence of cloudiness in the atmosphere that may be connected with ne- 
gative electricity, as the presence of certain clouds — cumulo-stratus for 
instance, or more probably cirro-stratus, from its almost constant occurrence 
with negative electricity. The remarkable changes that frequently occur 
from one kind of electricity to the other, often very suddenly, and at the 
same time very considerable in intensity, clearly show that at the time dis- 
turbances of no ordinary character prevail, and it may readily be conceived 
(in addition to the suggestion already offered) that different strata of cloud 
in different electrical states, operating on each other and on the earth, may 
very violently disturb the ordinary march either of the electricity of serene 
weather or of the aqueous vapour ; and although these disturbances (taking 
them singly and considering the great uncertainty of their occurrence) may 
be regarded as purely accidental and obeying no recognized law of periodicity, 
yet should they result from causes which in themselves are not subject to 
mere accidental manifestations, but are the results of forces operating on the 
earth's atmosphere in a definite manner — producing for instance a greater 
accumulation of cloud at one period of the day rather than at another, and 
giving rise to a well-defined march in the manifestation of the cloudiness of 
the atmosphere, within small limits it is true, but yet sufficient, from six years' 
careful observation, to characterize the curve as that of a single progression 



ON ELECTRICAL OBSERVATIONS AT KEW. 



197 



having an ascending and descending branch, the maximum occurring about 
40 minutes before noon, and the minimum between 9 and 10 at night — then 
they must necessarily exhibit somewhat of the same subjection to the laws 
of periodicity which is characteristic of the causes themselves. That the 
diurnal occurrence of negative electricity is of a periodical character, the ob- 
servations of five years, viz. from August 1843 to August 1848, testify in a 
very unequivocal manner ; and although its connexion with the general 
cloudiness of the atmosphere may not be satisfactorily made out, yet it by no 
means follows that it may not be more immediately connected with certain 
classes of cloud ; for as we have determined a diurnal period in the cloudiness 
generally, it is not unlikely that certain clouds, the cirro-stratus for instance, 
may likewise exhibit a diurnal period, being much more frequent in its oc- 
currence at one portion of the day rather than at another. Upon the whole, 
the negative readings are obvious indications of considerable disturbances, 
and their occurrence in much greater frequency at a particular period of the 
day renders it highly probable that the disturbances themselves are of a sy- 
stematic character and subject to well-defined laws of diurnal periodicity. 

Negative readings from January 1845 to July 1848 inclusive. — During 
this period 424 negative charges of the conductor were observed. Their 
distribution among the twelve observation-hours is seen in the following 
table, which also includes the mean value of the negative tension at each 
observation-hour, and the excess or defect of such mean as compared with 
the mean of the whole. 

Table XCVIII. 

Number of readings, mean tension, and excess or defect above or below 
the mean of all the negative observations from January 1845 to July 1848, 
as referred to the twelve observation-hours. 



























Sums 




Mid. 


2 a.m. 


4 a.m. 


6 a.m. 


8 a.m. 


10 a.m. Noon. 


2 p.m. 


4 p.m. 


6 p.m. 


8 p.m. 


10 p.m. 


and 

Means. 


Readings 


8 


12 


12 


18 


34 


56 46 


52 


55 


60 


38 


33 


424 




div. 


div. 


div. 


div. 


div. 


div. div. 


div. 


div. 


div. 


div. 


div. 


div. 


Tensions. 


360 


248 


109-4 


316-3 


9386 


566 2 871-7 


891-3 


907-6 


729-9 


721-9 


870-2 


725-3 


Excess I 


— 


— 


— 


— 


+ 


- 1 -f 


+ 


-f 


+ 


— 


+ 




or \ 


689-3 


700-5 


615-9 


4090 


213-3 


159-1 146-4 


166-0 


182-3 


4-6 


3-4 


144-9 


725-3 


Defect. J 



























We have already alluded to the greater frequency of the occurrence of nega- 
tive electricity in the middle of the day, and have remarked that the period 
under consideration agrees with the previous seventeen months in this parti- 
cular. The line of mean tensions in the above table, in addition to the greater 
frequency of occurrence in the middle of the day, exhibits upon the whole 
period a corresponding increase of tension, particularly from 8 a.m. to 4 p.m., 
a portion of the day characterized by the greater prevalence of cloud (see 
Table XCVI.). The maximum occurs at 8 a.m., but from the close approxi- 
mation in the values of the mean tensions at noon, 2 and 4 p.m., it can hardly 
be considered as the true maximum of the diurnal period : it is to be remarked 
that only 34 observations contribute to its determination, and until a more 
extended series can be obtained, it must remain a matter of question. The 
mean tensions at noon, 2 and 4 p.m., taken in connexion with those at 10 a.m. 
and 6 p.m., present a well-rounded and very regular portion of a curve, which 
in the absence of further observations may probably be considered as repre- 
senting at least approximately the portion of the diurnal period of negative 



198 



REPORT 1849. 



electricity from 10 a.m. to 6 p.m. At 8 p.m. the diminution is so exceedingly 
slight as almost to indicate a tendency to rise at that hour, and at 10 p.m. we 
have a decided increase : but in connexion with this, it should be borne in 
mind, that at one of the 33 observations contributing to its determination, the 
Henley's electrometer read 70° ; and it is easily seen that this high tension very 
materially influences the result, for if we abstract it, the mean tension is 
lower than that at 8 p.m. With regard to the mean tensions at midnight 
and 2 a.m., the same remarks apply which we offered relative to the positive 
tensions at these hours (see pages 118, 119) ; they are for the same reason pro- 
bably lower than the truth, and indeed more particularly so in the case of nega- 
tive electricity ; for it is likely that when such electricity has been indicated by 
the conductor on other occasions than the eight and twelve recorded, it has 
exhibited much higher tensions than 50 div. of Volta No. I. The remarkable 
difference between the values of the mean of all the positive observations for 
three years (66-9 div.) and of all the negative during 43 months (725*3 div.) 
is exceedingly interesting, as indicating at once the character of the move- 
ments giving rise to the negative exhibitions, viz. disturbances. 

Fig. 19. 



4 


6 8 12 








4 


6 


8 10 


S 






















— 




/ 


\ 


y 






\ 




-^ 


\ 






/ 
















\ 






^ 






■^ 


N 
























\ 








/ 
















\ 


"^ 


y 


/ 

























Negative 
Electricity, 



6 

P.M. 



Diurnal Curves of Negative Klectricity and Cloudiness. 

The annexed curves (fig. 19) exhibit to the eye the principal diurnal 
phaenomena of negative electricity and cloudiness : 1000 divisions of Volta's 
electrometer No. 1 are considered equal to two vertical divisions of the scale 
on which the negative tensions are projected ; eight hundredths of the scale of 
cloudiness being also considered equal to two of the same divisions. The 
points of the curve of cloudiness are placed about one-third of each horizontal 
division from the vertical or hour lines, the determination being at even hours 
of Gottingen mean time. The greater prevalence of cloud being in advance 
of the exhibition of negative electricity, which we noticed when treating of 
the frequency of its occurrence in the middle of the day, is very striking 
in the curves before us, which show that the same phfenomena obtain in the 
comparison of the two, whether we regard the occurrence or the value of the 
tension of negative electricity. There is also another feature which ought 
not by any means to be overlooked ; it is the similarity in this respect that 
exists between the curves of negative electricity and cloudiness, and those of 
the annual period of positive electricity and humidity (see page 153). In 



ON ELECTRICAL OBSERVATIONS AT KEW. 199 

both instances the cloudiness and humidity precede the electricity, and strongly 
indicate that whatever relation may exist between the development of positive 
electricity and humidity on the one hand, and that of negative electricity and 
cloudiness on the other, such relations are not only likely to be of a very 
constant character, but that a similarity exists between the two sets of phae- 
nomena which goes far to show that the nature of their connexion, if any, 
is also similar ; the one, viz. positive, principally indicating, as we have before 
remarked, the electric tension of aqueous vapour ; the other, viz. negative, 
the electrical disturbances produced by the sudden precipitation of this vapour 
when existing as cloud. 

It would greatly contribute to our knowledge of this part of our inquiry, 
if systematic and comparative observations were instituted at different observa- 
tories, on occasions of electrical disturbances, of a somewhat similar character, 
but of course considerably varied in their details, to those adopted on the oc- 
casions of magnetic disturbances. A principal feature in such observations 
should be tJie observation of the electrometers at regular but small intervals of 
time during the continuance of the disturbance, so that curves of the variations 
of the instruments might be readily projected at any time afterwards. Pro- 
vision should also be made for noting the precise instants at which particular 
and striking phaenomena occurred, such as lightning, thunder, a change in the 
kind of electricity/, the commencement of rain, the commencement of heavy rain, 
the termination of rain either light or heavy, also the same phcenomena as re- 
gards Imil or snow. A rain-gauge should also be kept for these particular 
phcenomena ; it should be of such a construction as to admit of its being fre- 
quently read during the continuance of the disturbance ; and its indications 
should be noted at sufficiently short intervals to afford data from which a 
curve could be constructed by which the eye coi^ld readily judge of the light- 
ness or heaviness of the rain by the amount precipitated within the interval 
fixed on. Observations of the kind just alluded to should by no means be 
confined to the more striking exhibition of electrical phaenomena, such as 
thunder-storms, &c., but upon the slightest, indication of a disturbance they 
should be immediately resorted to ; even on the positive tensions ranging 
higher than usual, the shorter intervals of observation may with great pro- 
priety be adopted, if it should be only for the purpose of securing on such 
extraordinary occasions the epoch of maximum ; and in all instances that it 
may be deemed advisable to resort to them, they should be continued while 
there is the least indication, either from the appearance of the sky or from 
the instruments, of the existence of the disturbance, and in fact until the ob- 
server is perfectly satisfied that it has ceased. It may be well to remark, that 
electrical disturbances appear to be very confined in their effects, extending 
over but a comparatively small portion of the earth's surface. 



Mr. Mallet's Report On the Facts of Earthquakes does not appear, as in- 
tended, in the present Volume, in consequence of the manuscript having been 
delayed by the author, pending his researches in foreign libraries, until too 
late for the period fixed for publication. 

The Report will appear in the Volume for next year. 



h 



NOTICES 



AND 

ABSTRACTS OF COMMUNICATIONS 

TO THE 

BRITISH ASSOCIATION 

FOB THE 

ADVANCEMENT OF SCIENCE, 

AT THE 

BIRMINGHAM MEETING, SEPTEMBER 1849. 



ADVERTISEMENT. 

The Editors of the following Notices consider themselves responsible 
only for the fidelity with which the views of the Authors are abstracted. 



CONTENTS. 



NOTICES AND ABSTRACTS OF MISCELLANEOUS 
COMMUNICATIONS TO THE SECTIONS. 

MATHEMATICS AND PHYSICS. 

Page 
Mr. J. C. Adams on the Application of Graphical Methods to the Solution of 

certain Astronomical Problems, and in particular to the Determination of 

the Perturbations of Planets and Comets 1 

Mr. Henry Blunt on a Model of the Moon's Surface 1 

Sir W. Hamilton on some new Applications of Quaternions to Geometry ... 1 

Mr. J. P. Joule on the Heat of Vaporization of Water 1 

Rev. Prof. Powell on De Vico's Comet 2 

on a new Equatorial Mounting for Telescopes 2 

Mr. Robert Rawson on the Friction of Water 3 

on Elliptic Integration 4 

on the Oscillations of Floating Bodies 5 

Sir David Brewster's Description of a Binocular Camera 5 

■ Improvement on the Photographic Camera 5 

' on a new form of Lenses, and their Application to the 

Construction of two Telescopes or Microscopes of exactly equal Optical Power 6 

Notice of Experiments on Circular Crystals 6 

Additional Observations on Berkeley's Theory of Vision 6 

Account of a new Stereoscope 6 

Lord Brougham's Experiments on the Inflection of Light 7 

Mr. J. A. Broun on the Diurnal Variation of Magnetic Declination and the 

Annual Variation of Magnetic Force 8 

Rev. H. M. Grover on an Orbitual Motion of the Magnetic Pole round the 

North Pole of the Earth 8 

Rev. Prof. Powell on some recent Discussions relative to the Theory of the 

Dispersion of Light 8 

on Irradiation 9 

Professor Stokes on a Mode of Measuring the Astigmatism of a Defective Eye 10 
on the Determination of the Wave Length corresponding with 

any point of the Spectrum II 

Professor Wheatstone on Professor Quetelet's Investigations relating to the 

Electricity of the Atmosphere, made with Peltier's Electrometer 11 

Mr. W. R. BiRT on Shooting Stars 15 

Mr. George Buist's Meteorological Phaenomena observed in India from 

January to May 1849 (communicated by Colonel Sykes) 15 



iv CONTENTS. 

Page 

Rev. Prof. Chevallier on a Rainbow seen after actual Sunset 16 

Mr. T. Hopkins's Notices of Mirage on the Sea Coast of Lancashire 16 

Sir Robert H. Inglis's Letter to Col. Sabine 17 

Dr. John Lee on Meteorological Observations made at KaaQord, near Alten, 

in Western Finmark, and at Christiania in Norway 18 

Mr. T. Hopkins on the Means of Computing theQuantity of Vapour contained 

in aVertical Column of the Atmosphere 24 

Mr. Edward Joseph Lowe on Meteors 24 

Admiral Sir C. Malcolm's Notice of a Meteor seen in India on the 19th of 

last March 24 

Mr. FoLLETT Osler on the Results of certain Anemometers 25 

Mr. Augustus Petermann on the Temperature of the British Islee, and its 

influence on the Distribution of Plants 26 

Mr. John Phillips's Contributions toAnemometry — The Therm-anemometer 28 

Rev. Prof. Powell on Luminous Meteors 29 

Rev. T. Rankin's Meteorological Observations made at Huggate, Yorkshire... 29 

on a singular Atmospheric Wave, in February 1849 29 

on a Phosphoric Phaenomenon in a Pond at Huggate, on June 

nth, 1849 29 

on Magnetized Brass 29 

Mr. George Rush on Observations of the Barometer and Thermometer, made 

during several Ascents in Balloons 29 

Mr. J. Scott Russell on Recent Applications of the Wave Principle to the 

Practical Construction of Steam-Vessels 30 

Mr. James Latto's Specimens of Incombustible Cloth 33 

Rev. Dr. Thomson on Meteorology considered chiefly in relation to Agriculture 33 

Mr. Henry Twining on Teaching Perspective by Models 33 

CHEMISTRY. 

Mr. G. Bontemps's Inquiries on some Modifications in the Colouring of Glass 

by Metallic Oxides 34 

Mr. C. Brooke on an Improvement in the Preparation of Photographic Paper, 
for the purposes of Automatic Registration ; in which a long-continued action 

is necessary 34 

Mr. A. Claudet's Researches on the Theory of the principal Phsenomena of 

Photography in the Daguerreotype Process 35 

Dr. De Vrij on the Black Colouring Matter of the Lungs 36 

M. Ebelmen on Artificial Gems 36 

Professor Forchhammer on the Formation of Dolomite 36 

on a New Method of ascertaining the Quantity of 

Organic Matter in Water 37 

Mr. J. H. Gladstone on the Compounds of the Halogens with Phosphorus... 38 
Mr. Samuel Howard on a continued spontaneous Evolution of Gas at the 

Village of Charlemont, Staffordshire 38 

Dr. John Percy on Copper containing Phosphorus, with Details of Experi- 
ments on the Corrosive Action of Sea- water on some Varieties of Copper.... 39 
Prof. W. B. Rogers and Prof. R. E. Rogers on the Decomposition and partial 
Solution of Minerals, Rocks, &c. by pure Water and Water charged with 

Carbonic Acid., 40 

Prof. Schroetter on the Allotropic Condition of Phosphorus 42 



CONTENTS. V 

Page 
Dr. ScoFFEHN on the combined Use of the Basic Acetates of Lead and Sulphu- 
rous Acid in the Colonial Manufacture and the Refining of Sugar 42 

Dr. A. VcELCKER on the Composition of the Ash of Armeria maritima, grown 
in different Localities, and Remarks on the Geographical Distribution of that 

Plant, and the Presence of Fluorine in Plants 43 

Mr. W. H. Walenn on a Form of Galvanic Battery 45 

Mr. W. Sykes Ward on Motions exhibited by Metals under the Influence of 

Magnetic and Diamagnetic Forces 46 

■ ■ on a Theory of Induced Electric Currents, suggested by 

Diamagnetic Phsenomena 46 

on the comparative Cost of working various Voltaic 



Arrangements 47 

Mr. W. West on the Presence of Nitrogen in Mineral Waters 47 

Mr. George Wilson on the Presence of Fluorine in the Waters of the Firth 

of Forth, the Firth of Clyde, and the German Ocean 47 

Mr. F. C. Wrightson's Analytical Investigations of Cast Iron 49 



GEOLOGY AND PHYSICAL GEOGRAPHY. 

Mr. Robert A. C. Austen's Notes on the Geology of the Channel Islands ... 49 

Mr. E. Charjlesworth on some New Species of Testacea from the Hampshire 
Tertiary Beds 52 

Mr. John Hogg on the Geography and Geology of the Peninsula of Mount 
Sinai and the adjacent Countries 52 

Mr. J. Beete Jukes on the Relations between the New Red Sandstone, the 
Coal-measures, and the Silurian Rocks of the South Staffordshire Coal-field. 55 

Mr. Isaac Lea on Traces of a Fossil Reptile (_Sauropus primeevus) found in the 
Old Red Sandstone (communicated by Dr. Buckland) 56 

Dr. G. Lloyd on a New Species of Labyrinthodon from the New Red Sand- 
stone of Warwickshire 56 

Mr. John Morris's Note on the Genus Siphonotreta, with a Description of a 
New Species (communicated by Sir R. I. Murchison) 57 

M. Barrande's Discovery of the Metamorphosis of certain Trilobites (commu- 
nicated by Sir R. T. Murchison) 58 

Sir R. I. Murchison on the Distribution of Gold Ore in the Crust and on the 
Surface of the Earth 60 

Mr. C. W. Peach on the Fossil Geology of Cornwall 63 

Mr. John Plant's Notice of the Discovery of Beds of Keuper Sandstone con- 
taining Zoophytes in the Vicinity of Leicester 64 

Mr. LovELL Reeve on the Discovery of a Living Representative of a small 
Group of Fossil Volutes occurring in the Tertiary Rocks 64 

Mr. William Sanders on the Age of the Saurians named Thecodontosaurus 
and PaltBOsaurus 65 

The Dean of Westminster on the Cause of the general Presence of Phos- 
phorus in Strata and in all fertile Soils; also on Pseudo-Coprolites, and the 
Conversion of the Contents of Sewers and Cesspools into Manure 67 

The Rev. D. Williams on an original broad Sheet of Granite, interstratified 
among Slates with Grit Beds, between Falmouth and Truro in Cornwall .... 68 



VI CONTENTS. 

ZOOLOGY AND BOTANY. 

Page 
Mr. Robert A. C. Austen on some Changes in the Male Flowers of Forty 
Days' Maize 68 

on a Series of Morphological Changes observed in 

TVifolium repens ^ 68 

Prof. BucKMAN on Fairy Rings, with Notes on some of the Edible Fungi by 

which they are caused 70 

Prof. E. Forbes on a remarkable Monstrosity of a Vinca ' 70 

on the Varieties of the Wild Carrot 70 

Dr. Edwin Lankester on some Abnormal Forms of the Fruit of Brassica 

oleracea 71 

Mr. G. MuNBY on the Vegetable Productions of Algiers 71 

Prof. Allman on the Nervous System and certain other Points in the Anatomy 

of the Bryozoa 71 

■'■ on aNew Freshwater Bryozoon 72 

■ on the Reproductive System of Cordylophora lacustris, Allm 72 

■ on Lophopus crystallina, Dumortier 72 

Mr. C. Spence Bate's Notes on some Tubicolse 72 

Notes on the Boring of Marine Animals 73 

Prof. E. Forbes on the Genera of British Patellacea 75 

on Beroe Cucumis, and the Genera or Species of Ciliograda 

which have been founded upon it 76 

Mr. R. Fowler — If Vitality be a Force having Correlations with the Forces, 
Chemical Affinities, Motion, Heat, Light, Electricity, Magnetism, Gravity, 
so ably shown by Professor Grove to be modifications of one and the same 

Force? 77 

Dr. Macdonald on the Course of the Blood in the Circulation of the Human 
Foetus in the Normal Developement, compared with the Acardian, Reptilian, 

and Ichthic Circulation 78 

-^— ^ on the External Antennae of the Crustacean and Entomoid 

Class, and their Anatomical Relation and Function, showing their connexion 
with the Olfactory instead of the Auditory Apparatus, and the Homology in 

the Vertebrate Class 78 

Professor Owen on Lucernaria inauriculata 78 

Dr. James Paxton on Improvements in Pathological Drawing 79 

Mr. C. W. Peach on the Luminosity of the Sea on the Cornish Coast 80 

Dr. Pring's Observations and Experiments on the Noctiluca miliaris, the Ani- 
malcular Source of the Phosphorescence of the British Seas ; together with a 

few general remarks on the pheenomena of Vital Phosphorescence 81 

Mr. H. E. Strickland's Notice of two additional Bones of the Long-legged 

Dodo or Solitaire brought from Mauritius 

Mrs. Whitby on the Growth of Silk in England 

ETHNOLOGY. 



: 



Dr. Blair on some remarkable Primitive Monuments existing at or near Carnac 
(Brittany) ; and on the Discrimination of Races by their local and fixed Mo- 
numents 82 

Mr. J. Craufurd on the Alphabet of the Indian Archipelago 83 



CONTENTS, VII 

Page 

Mr. J. Crawfurd on the Oriental Words adopted in English 84 

Rev. A. J. Ellis on Ethnical Orthography 85 

Rev. J. Hanson on the Gha Nation of the Gold Coast of Africa 85 

Mr. A. K. IsBisTER on the Ethnology of New Caledonia 85 

Dr. R. G. Latham on certain Additions to the Ethnographical Philology of 

Africa 85 

— on the Transition between the Tibetan and Indian Families 

in respect to conformation 85 

■ on the terms Gothi and Getae 85 

Mr. J. Phillips on Tumuli in Yorkshire 86 

Prof. Retzivs on a Finlandic Vocabulary 86 

on certain American, Celtic, Cimbric, Roman and Ancient Bri- 
tish Skulls 86 

STATISTICS. 

Prof. W. P. Alison on the Application of Statistics to the Investigation of 

the Causes and Prevention of Cholera 86 

The Chevalier Bunsen on Prussian Statistics 86 

Mr. C. HoLTE Bracebridge on the County of Warwick Asylum for Juvenile 

Offenders 87 

Mr. J. T. Danson on the Fluctuations of the Annual Supply and average Price 
of Corn, in France, during the last seventy years, with particular reference to 

the four periods ending in 1792, 1814, 1830, and 1848 87 

— on the Progress of Emigration from the United Kingdom 

during the last Thirty Years relatively to the Growth of the Population 88 

Dr. C. Finch on the Diseases and Causes of DisabiUty for Military Service in 

the Indian Army 89 

Professor W. N. Hancock on a Form of Table for Collecting Returns of Prices 

in Ireland 92 

on the Use to be made of the Ordnance Survey in 

the Registration of Judgments and Deeds in Ireland 93 

'■ on the Usury Laws — Statistics of Pawnbroking 93 

on the Discovery of Gold in California 94 

Mr. J. Paton's Letter on the Sanitary Condition of Darwen, Lancashire, with 

Suggestions for its Improvement 96 - 

Very Rev. G. Peacock on the Tenure of Land in the Island of Madeira 96 

Mr. G. R. Porter on a Comparative Statement of Prices and Wages during 

the Years from 1842 to 1849 101 

' on the Agricultural Statistics of Ireland 104 

Lieut.- Col. Sykes's Contributions to the Statistics of Sugar produced in India 108 
• ■ Statistical Account of the Labouring Population inha- 
biting the Buildings at St. Pancras, erected by the Metropolitan Society for 
improving the Dwellings of the Poor 108 

MECHANICAL SCIENCE. 

Mr. J. G. AppoLD on a Centrifugal Pump 110 

Mr. Bakewell on the Copying Telegraph, and other recent Improvements in 

Telegraphic Communication 110 

On the Britannia Bridge , Ill 



Vm CONTENTS. 

Page 

Mr. William Brunton on a Machine for Ventilating Coal Mines Ill 

Mr. A. G. Carte on the Use of Rockets in effecting a Communication with 

Stranded Vessels 114 

Mr. Robert Davison on a Desiccating Process 114 

Mr. W. Greener on the Manufacture of the Finer Irons and Steels, as ap- 
plied to Gun-Barrels, Swords, and Railway Axles 115 

Mr, George Heaton on the Cause and Prevention of the Oscillation of Loco- 
motive Engines on Railways 116 

Prof. HoDGKiNsoN on the Strength and Elasticity of Stone and Timber 118 

Mr. H. Knight on a Calculating Instrument 118 

The Rev. J. W. M'Gauley on a New Rotary Engine 118 

Mr. A. MiLWARD on an Instrument called the " Upton Draining Tool," as 
illustrating a principle by which the resistance of Soils to Agricultural Im- 
plements may be considerably diminished 122 

Mr. James Nasmyth on an Oil Test 124 

Mr. Wm. Nicholson on Gordon's Plan of Ventilating Coal Mines 125 

Mr. W. Parkinson on a Water Meter 125 

Mr. Richard Roberts on the Sheet-Metal Moulding Machine 126 

on correct Sizing of Toothed Wheels and Pinions 127 

on the Excentric Sheet-Metal and Wire-Gauge 128 

Mr. J. PiGOTT Smith on the Superiority of Macadamized Roads for Streets of 

large Towns 129 

Mr. W. Sykes Ward on a Method of supplying the Boilers of Steam-Engines 

with Water 132 

Mr. Whishaw on Chain Pipes for Subaqueous Telegraphs 132 

■ on the Present State of Electro-Telegraphic Communication 

in England, Prussia, and America 133 

Mr. Wood on Kosman's Patent Cistern as a Sanitary Machine 134 



NOTICES AND ABSTRACTS 



MISCELLANEOUS COMMUNICATIONS TO THE SECTIONS. 



MATHEMATICS AND PHYSICS. 

On the Application of Graphical Methods to the Solution of certain Astrono- 
mical Problems, and in particular to the Determination of the Perturba- 
tions of Planets and Comets, By J. C. Adams, F.R.S. 

After briefly pointing out the advantages of graphical methods, the author pro- 
ceeded to give some instances of their practical application. It was shown that the 
solution of the transcendental equation which expresses the relation between the 
mean and excentric anomalies in an elliptic orbit, is obtained in the most simple 
manner by the intersection of a straight line with the curve of sines. Attention 
was directed to Mr. Waterston's graphical method of finding the distance of a comet 
from the earth, and an analogous method was given for determining the distance of 
a planet, on the supposition that the orbit is a circle in the plane of the ecliptic. 

The author then passed on to the more immediate object of his communication, 
the graphical treatment of the problem of perturbations of planets and comets. He 
first showed how to obtain geometrical representations of the disturbing forces, and 
then gave simple constructions for determining the changes produced by these forces 
in each of the elements of the orbit, in a given small interval of time. Having ob- 
tained the total changes of the elements in any number of such intervals, it was 
shown in the last place how to find their effect on the longitude, radius vector and 
latitude of the disturbed body, and thus'to efi^ect the complete solution of the pro- 
blem of perturbations without calculation. 

On a Model of the Moon's Surface, By Henry Blunt. 

This model is an accurate representation of a part of the moon's surface as it 
appears through a Newtonian telescope of seven feet focus and nine inch aperture, 
under a magnifying power of about 250. The large volcanic crater, which forms the 
principal object in the model, has received the name of Eratosthenes. It is about thirty 
miles in diameter and stands at the end of a lofty range of mountains not far from 
the centre of the moon's disc. A hilly district, rising into two or three lofty peaks, 
runs upwards from Eratosthenes, connecting it with what appears to have been an 
ancient crater now filled up. Touching the edge of this crater and descending from 
it towards the right, may be seen a long line of minute volcanic cups, which are 
nearly the smallest objects visible with the instrument by which the observations 
were made. The whole is represented as seen with an inverting eye-piece, and the 
model ought to be held in an oblique light in order to view it to advantage. 

On some new Applications of Quaternions to Geometry. 
By Sir W. Hamilton. 

0?i the Heat of Vaporization of Water. By J. P. Joule. 

The object was to point out the complex nature of the heat hitherto taken for 

the latent heat of steam. In the exact experiments of Regnault 965° was found 

to be the quantity of heat evolved in the condensation of steam saturated at 212° ; 

of this quantity 75° was stated by the author to be the heat due to the vis viva com- 

184;9. 1 



2 REPORT — 1849. 

municated by the pressure of the steam, leaving 890° as the true heat of vaporization 
of water. In a perfect steam-engine, supplied with water at 212° and worked at 
atmospheric pressure without expansion, 965° will be the heat communicated from 
the fire to the boiler, 75° will be the heat utilized by conversion into force, and the 
remainder, 890°, will be the heat given out in the condenser. 

By working the steam expansively, so as to utilize its sensible heat, the oeconomi- 
cal duty may be at least doubled. In this case 150° out of 965° communicated to 
the boiler will be converted into force, leaving only 815° to be evolved in the con- 
denser. 

On De Vico's Co»isL By the Rev. Prof. Powell, F.R.S. i^c. 

The author called the attention of the Section to the expected return of this comet, 
the first since its discovery. It will come to its perihelion on Feb. 6, 1850, but will 
be in such a position with respect to the earth as probably to render it quite invi- 
sible. The annexed diagram gives a rough idea of its positions. 




Prof. Chevallier has since printed an Ephemeris of the comet : the only period 
during which it could possibly be seen would be in October 1849. 

On a new Equatorial Mounting for Telescopes. 
By the Rev. Prof. Powell, F.R.S. Sfc. 

The object of the plan here proposed is mainly the personal convenience of the 
observer, and the ease and rapidity of changing to a new position, which is often a 
matter of more importance than mere comfort. 



TRANSACTIONS OF THE SECTIONS. 



The essential principle of the construction (see the annexed section in the plane 
of the meridian) consists in making the telescope (T) move about a point (C), at, or 
a little beyond, its eye-hole, instead of, as usual, about its middle point, by means 
of a counterpoise (W). The telescope projects sufficiently from the frame (F) which 




carries it to allow room for the head of the observer ; and to this frame is attached 
the declination-axis (D), turning in supports from the lower frame (F), through the 
arm of which passes the polar axis (P), fixed to a firm pier, and round which the 
whole is counterpoised by the weight (W). 

When the whole is in the plane of the meridian the axis of the telescope coincides 
with the polar axis, and the point of intersection (C) of the polar and declination 
axes, is the position of the eye of the observer, or centre of motion, which is an 
invariable point in space for all altitudes and azimuths. A perpendicular dropped 
from this point gives a point (V) on the floor, at which a pivot is fixed, round which 
the observing couch (inclined at a constant angle) can revolve through a semicircle 
horizontally. The observer has only to push himself round in azimuth, and, in any 
given azimuth, he commands all altitudes in the plane of a circle at right angles to 
that azimuth, by simply turning his head from one side to the other. 

The possible objection of want of steadiness in the telescope is one which can 
only be judged of by actual trial ; but for telescopes of moderate size there seems no 
reason to apprehend that with well-constructed framing, axes, and counterpoises, 
sufficient steadiness might not be attained. 

The same piinciple is obviously, and with greater simplicity, applicable to small 
transits and moveable telescopes. In the latter case it has been successfully put to 
trial by the author. 



On the Friction of Water. By Robert Rawson. 
The object of this paper is to ascertain the friction of water on a vessel or other 
floating bodies rolling in water. For this purpose experiments have been made 
upon a cylindrical model whose length is 30 inches, diameter 26 inches, and weight 
255"43 lbs. avoirdupois, in the following manner. The cylinder was placed in a 
cistern, in the first place, without water, and made to vibrate on knife-edges passing 
through the axis of the cylinder ; a pencil projecting from the model in the direc- 
tion of the axis of the cylinder on the surface of another moveable cylinder marked 
out upon paper placed upon this last cylinder the amplitude of each oscillation. 

1* 



22 


30 


22 


10 


21 


5* 


21 


36 



4 REPORT — 1849. 

The cylinder was deflected over to various angles by means of a weight attached by 
a string to the arm of a lever fixed to the cylindrical model. 

Angle of deflection. Angle to which the model vibrated, 

O / O / 

22 24 
22 6 
21 48 
21 30 
&c. &c. 

When the cylinder oscillated, in all circumstances the same as above, except 
being surrounded by salt water, the amplitude of oscillation was as follows : — 

Angle of deflection. Angle to which the model vibrated. 

O / O / 

22 30 22 

21 36 21 3 

20 48 20 16 

&c. &c. 

Clearly showing that the amplitude of vibration, when oscillating in water, is con- 
siderably less than when oscillating without water : in the above instance there is a 
falling off in the angle of amplitude of 24', or nearly half of a degree. This amount 
has been confirmed by several experiments made with great care; and it appears 
only fair to attribute this decrease in the amplitude of oscillation to the circumstance 
of the friction of the water on the surface of the cylinder. The amount of force 
acting on the surface of the cylinder necessary to cause the decrease in the ampli- 
tude of oscillation shown by the experiment was calculated, and the author thinks 
that this amount of force is not equally distributed on the surface of the cylinder : 
in consequence of this he thought the amount on any particular part might vary as 
the depth. On this supposition a constant pressure at a unit of depth is assumed ; 
this, multiplied by the depth of any other point of the cylinder immersed in the 
•water, will give the pressure at that point. These forces or moments being summed 
by integration and equated with the sum of the moments given by the experiments, 
we shall have the following value of the constant pressure at a unit of depth, 
•0000469. This constant in another experiment, the weight of the model -heing 
197 lbs. avoirdupois, (and consequently the part immersed in the water was very 
different from the other experiment) was "0000452, which differs very little from the 
former ; showing that the hypothesis assumed in computation is not far from the 
truth. 



On Elliptic Integration. By Robert Rawson. 

The object of this communication is, in the first place, to change the form of the 
elliptic function from that involving the square of the sine of the amplitude to a 
form involving simply the cosine of the amplitude, by means of the well-known 
trigonometrical formula, that twice the sine of half an arc squared is equal to unity 
minus the cosine of the same arc. 

The author believes this form of the elliptic function to possess several advantages, 
and therefore would be more useful to tabulate than the form of Legendre, whose 
tables are not in a good practical form for use. With a view to tabulate this func- 
tion in a more extensive manner than Legendre has done, several investigations 
have been, made to compare the functions of the first order with different amplitudes 
and moduli ; a formula for this purpose has been obtained where the relation be- 
tween the amplitudes is much more simple than that discovered by Lagrange. 

A different mode of investigation has been pursued by the author than that pur- 
sued by Lagrange, Legendre, Abel, or any authors who have written on this sub- 
ject ; and by taking a relation between" the amplitudes expressed Ijy means of an 
unknown function of one of the amplitudes, we are conducted to tw6 equations, the 
first of which is an elliptic function of the first order, equal to a constant times an- 
other integral of an arbitrary character, and the second a functional equation, which 
must be satisfied, between the function assumed in the relation of the amplitudes and 



TRANSACTIONS OF THE SECTIONS. 5 

the function assumed in the arbitrary integral by means of which the elliptic integral 
is compared. 

If we want to compare the elliptic function with another elliptic function of the 
same kind but a different modulus, the function in the arbitrary integral will be the 
same radical which enters in the elliptic integral ; but if the object be to compare 
the elliptic function with any other integral of a different form, the function in the 
arbitrary integral will be fixed, and depend upon the form of the integral thus used. 

Various rational forms have been given to this arbitrary integral, with a view to 
compare the elliptic functions with functions that can be integrated, and amongst 
them one has been found to answer the conditions of the functional equation, and 
also to be integrable by means of logarithms and circular arcs. 

On the Oscillations of Floating Bodies. By Robert Rawson. 

This paper had for its object the description of a course of experiments made at 
Portsmouth Dockyard by Mr. John Fincham, the master shipwright, and the author, 
with a view to confirm several important formulee discovered by Professor Moseley 
relative to the rolling and pitching motion of vessels. All the experiments, which 
were made by Admiralty order, confirm the formulas for determining the amount of 
force or work done to deflect a floating body in a state of equilibrium through a 
given angle, and also another formula which determines whether the vessel thus 
deflected will move slowly or otherwise. 

The importance of these questions to naval architecture is obvious ; and all the 
experiments we have made show what we believe to be an important practical fact, 
viz. that when a sudden gust of wind is applied to the sails of a vessel, or any cause 
which acts constantly during one oscillation, the ultimate amplitude of deflection 
will be double the amplitude which the gust of wind will permanently deflect the 
vessel. 

In the next part, several experiments were made on models of vessels, some of 
which have been built with a view to ascertain the best form of midship section 
which will give the easiest rolling motion. 

Description of a Binocular Camera. 

By Sir David Brewster, K.H., D.C.L., F.R.S., 8s V.P.R.S. Edin. 

This instrument affords to amateurs and artists a ready mode of obtaining double 
drawings both of colossal statues and of living bodies or of fixed structures, for the 
purpose of having them exhibited as solids by the stereoscope. As the camera re- 
quired for this purpose must have two lenses of exactly the same focal length, in 
order to form by the Daguerreotype or Talbotj'pe processes the two pictures required, 
with mathematical precision. Sir David has constructed his double camera by di- 
viding a suitable lens, either single or achromatic, into two semi-lenses, each of which 
will form an image exactly like that which the entire lens would have formed, though 
with less light. These semi-lenses, placed at the proper distance from each other 
and from the object, give the two pictures as required for producing the effect of 
relief when seen by each eye at once in a stereoscope. 

Improvement on the Photographic Camera. 
By Sir David Brewster, K.H., D.C.L., F.R.S., ^ V.P.R.S.Edin. 
Sir David Brewster gave an account of an improvement which he had made and 
used on the Photographic Camera. In order to observe when the picture was most 
distinct on the paper or metal, he views the picture with a single or a compound 
eye-piece, either when the picture is received on the ground-glass plate, or in the 
air when the ground-glass is removed. In this last case the camera becomes an 
excellent telescope, by which the satellites of Jupiter as well as other astronomical 
phaenomena may be easily seen. The ground-glass may be wholly dispensed with, 
or it may be permanently connected with the eye-piece, and drawn back when it is 
out of use. If the ground-glass is retained, a hole opposite the eye may be made in 
it, or that part of the gliiss may be left unground. This construction of the Camera, 
by which the focus can be adjusted with the greatest accuracy, has been adopted and 
successfully by Mr. Beickle of Peterborough, who has executed some of the finest 
Talbotype we have seen. 



6 REPORT — 1849. 

O71 a new form of Lenses, and their Application to the Construction of two 
Telescopes or Microscopes of exactly equal Optical Potver. By Sii* David 
Brewster, K.H., D.C.L., F.R.S., 4- V.P.R.S. Edin. 

This method is to divide, in the same way as before described, one lens into two 
serai-lenses or quadrants, or sextants or octants, and using each semi-lens or quadrant 
for forming the image. Sir David also showed, that by a proper combination and 
adjustment of two such serai-lenses or quadrants in a frarae or tube, by placing 
their diameters at a proper angle, each may be raade to correct the imperfect image 
formed by the other. 

Notice of Experiments on Circular Crystals. 
By Sir David Brewster, K.H., D.C.L., F.R.S., ^- V.P.R.S. Edin. 

Mr. Fox Talbot first studied the phenomena of this class of crystals as exhibited 
in those produced by a mixture of borax and phosphoric acid, and Sir David Brewster 
exhibited to the Section drawings of this phsenomenon which had been presented to 
hira by Mr. Fox Talbot. In the course of his own inquiries he discovered a large 
number of bodies which yielded circular crystals, which he divided into two classes, 
positive and negative, including oil of mace (the phsenomena of which he had pre- 
viously described in the Phil. Trans, for 1814), animal fat, wax, &c., in which it is 
very difficult to distinguish circular from quaiiuaversits polarization. 

Additional Observations on Berkeley's Theory of Vision. 
By Sir David Brewster, K.H., D.C.L.,' F.R.S., ^- V.P.R.S. Edin. 

Tn this paper, the author, by various arguments, partly metaphysical, partly optical, 
and by examining the accounts of persons couched for cataract at an advanced period 
of life, which were relied on by the supporters of Berkeley's views (illustrating his 
views by several diagrams), considered he had overthrown every position essential to 
the maintenance of that theory, and especially the fundamental proposition from which 
that philosopher started. ______ 

An Account of a. nav Stereoscope. 
By Sir David Brewster, K.H., D.C.L., F.R.S., S,- V.P.R.S. Edin. 

The ingenious stereoscope, invented by Professor Wheatstone for representing 
solid figures by the union of dissimilar plane pictures, is described in his very in- 
teresting paper "On some remarkable and hitherto unobserved Phsenomena of 
Binocular Vision ;" and in a paper published in a recent volume of the Edinburgh 
Transactions, Sir David Brewster has investigated the cause of the perception of 
objects in relief, by the coalescence of dissimilar pictures. Having had occasion to 
make numerous experiments on this subject, he was led to construct the stereoscope 
in several new forms, v^'hich, while they possess new and important properties, have 
the additional advantages of cheapness and portability. The first and the most 
generally usfful of these forms is the Lenticular Stereoscope. This instrument con- 
sists of two serailenses placed at such a distance that each eye views the picture or 
drawing opposite to it through the margin of the semilens, or through parts of it 
equidistant from the margin. The distance of the portions of the lens through which 
we look, must be equal to the distance of the centres of the pupils, which is, at an 
average, 2^ inches. The serailenses should be placed in a frame, so that their di- 
stance may be adjusted to different eyes. When we thus view two dissimilar draw- 
ings of a solid object, as it is seen by each eye separately, we are actually looking 
through two prisms, which produce a second or refracted image of each drawing, and 
when these second images unite, or coalesce, we see the solid object which they re- 
present. But in order that the two images may coalesce without any effort or strain 
on the part of the eyes, it is necessary that the distance of similar parts of the two 
drawings be equal to iicice the refraction produced by each lens. For this purpose, 
measure the distance at which the serailenses give the most distinct view of the 
drawings, and having ascertained, by using one eye, the amount of the refraction 
produced at that distance, or the quantity by which the image of one of the draw- 
ings is displaced, place the drawings at a distance equal to twice that quantity. 



TRANSACTIONS OF THE SECTIONS. 7 

that is, place the drawings so that the average distance of similar parts in each is 
equal to twice that quantity. If this is not correctly done, the eye of the observer 
will correct the error, by making the images coalesce, without being sensible that it 
is making any such effort. When the dissimilar drawings are thus united, the solid 
will appear standing, as it were, in relief, between the two plane representations of 
it. In looking through this stereoscope, the observer may probably be perplexed 
by the vision of only the two dissimilar drawings. This effect is produced by the 
strong tendency of the eyes to unite two similar, or even dissimilar drawings. No 
sooner do the refracted images emerge from their respective drawings, than the eyes, 
in virtue of this tendency, force them back into union ; and though this is done by 
the convergency of the optic axes to a point nearer the eye than the drawings, yet 
the observer is scarcely conscious of the muscular exertion by which this is effected. 
This effect, when it does occur, may be counteracted by drawing back the eyes from 
the lenses, and shutting them before they again view the drawings. While the serai- 
lenses thus double the drawings and enable us to unite two of the images, they at 
the same time magnify them, — an advantage of a very peculiar kind, when we wish 
to give a great apparent magnitude to drawings on a small scale, taken photogra- 
phically with the camera. The lenticular stereoscope may be made of any size. 
Sir David Brewster then described how we may see at the same time a raised and a 
hollow cone, the /ormer being produced by the union of the ^rs/ with the secoirf, and 
the latter by the union of the second with the third figures. This method of exhi- 
biting at the same time the raised and the hollow solid, enables us, he said, to give 
an ocular and experimental proof of the usual explanation of the cause of the large 
size of the horizontal moon, of her small size when in the meridian at a considerable 
altitude, and her intermediate apparent magnitude at an intermediate altitude. As 
the summit of the raised cone appears to be nearest the eye of the observer, the 
summit of the hollow cone furthest off, and that of the flat drawing on each side at 
an intermediate distance, these distances will represent the apparent distance of 
the moon in the zenith of the elliptical celestial vault, in the horizon, and at an alti- 
tude of 45°. The circular summits thus seen are in reality exactly of the same size, 
and at the same distance from the eye, and are therefore precisely in the same 
circumstances as the moon in the three positions already mentioned. If we now 
contemplate them in the stereoscope, we shall see the circular summit of the hollow 
cone the largest, like the horizontal moon, because it seems at the greatest distance 
from the eye ; the circular summit of the raised cone the smallest, because it appears 
at the least distance, like the zenith moon ; and the circular summit of the cones 
on each of an intermediate size, like the moon at an altitude of 45°, because their 
distance from the eye is intermediate. No change is produced in the apparent 
magnitude of these circles by making one or more of them less bright than the 
rest, and hence we see the incorrectness of the explanation of the size of the hori- 
zontal moon, as given by Dr. Berkeley. When the observer fails to see the object in 
relief from the cause already mentioned, but sees ozily the two drawings, if there are 
two, or the three drawings, if there are three, the plane of the drawings appears 
deeply hollow ; and, what is very remarkable, if we look with the eccentric lenses at a 
flat table from above, it also appears deeply hollow, and if we touch it with the palm 
of our hand, it is felt as hollow, while we are looking at it, but the sensation of 
hoUowness disappears on shutting our eyes. Sir David Brewster described a variety 
of forms in which he had constructed the stereoscope, by means of lenses, mirrors 
and prisms. The sense of sight, therefore, instead of being the pupil of the sense 
" of touch, as Berkeley and others have believed, is, in this as in other cases, its 
teacher and its guide. Sir D. Brewster's simplified stereoscopes may not only be 
" rendered portable, but may be constructed out of materials which every person pos- 
. sesses, and without the aid of an optician. A fuller account of these instruments 
will be found in the forthcoming volume of the Transactions of the Royal Scottish 
Society of Arts. 



Experiments on the Inflection of Light. By Lord Brougham, F.R.S. 

A communication from Lord Brougham was read by Sir David Brewster. His 
Lordship's experiments were made at his seat at Cannes in Provence, with a very fine 



8 REPORT — 1849. 

and ingenious apparatus executed by that distinguished optician, M. Soleil of Paris, 
and with the aid of a heliostat for fixing the sun-beam in one position during the 
day. The results obtained by Lord Brougham establish a new and interesting pro- 
perty of light, namely, that when a pencil of divergent light has suffered inflection 
by a metallic or any other edge, of any form or substance, it exhibits different pro- 
perties on its different sides when submitted to the action of a second inflecting edge. 
The heliostat being a rare and expensive instrument, and of difficult construction. 
Lord Brougham offered the use of his to any members of the Association who might 
be occupied with experiments on light which required the assistance of it. 



On the Diurnal Variation of Magnetic Declination and the Annual Varia- 
tion of Magnetic Force. By J. A. Broun. 

The details of these results will be found in vol. xix. part 2 of the Transactions 
of the Royal Society of Edinburgh. 

On an Orbitual Motion of the Magnetic Pole round the North Pole of the 
Earth. By the Rev. H. M. G rover. 

This subject was investigated by tracing the positions of the magnetic pole at se- 
veral intervals during the period of the last 250 years, by converging lines drawn 
from the London, Paris and St. Petersburg Observatories, and deduced by compu- 
tations of the different variations of the magnetic needle at these places. These 
changes were shown very distinctly upon the different polar horizons of the obser- 
vatories, and the orbit drawn from them in its proper position. An extraordinary 
acceleration of this motion from 1580 down to 1723 was pointed out, and a pause 
at that period, which indicated a climax in that year, in which both the horizontal 
movement of the needle was suspended, and the dipping motion changed its course 
from a downward to an upward motion. Mr. Grover showed also a series of changes 
in the lines of equal declination about the isodynamic poles, which appeared to in- 
dicate a direct tendency, or attractive force operating upon the magnetic needles 
from those poles, which he assumed and showed to be suflicient to account for the 
extra linear position of the line of no declination between Europe and Asia, as well 
as for the extraordinary curvatures of the declination lines observed in the north of 
Asia on the two sides of the isodynamic pole, and the origin and changes of the 
closed systems or ovals in their Asiatic and Pacific allocations. Mr. Grover regarded 
the moving magnetic pole in the light of a satellite, or supplemental system, to the 
isogonal poles, disturbed by the accumulations of ice about the pole in the course of 
a long series of ages, and generated as a compensative process from an interruption 
of the original system. 

On some recent Discussio7is relative to the Theory of the Dispersion of Light, 
By the Rev. Prof. Powell, F.R.S. ^-c. 

Two eminent continental writers have recently published some discussions on this 
subject, which seem to call for a few brief remarks. 

M. Mossotti, in a memoir " On the Spectrum of Fraunhofer," &c. (Paris, 1845, 
transl. in Taylor's Foreign Scientific Memoirs, No. xix. p. 435), compares the in- 
terference or grating spectrum, with that formed by refraction, as to the intensity of 
light at its different parts, and the relation of the deviation to the values of X, the 
wave length, which in the former is simple and normal. 

As to any measures of the intensity of light at different parts of the spectrum, it 
appears to be a necessary condition to state the kind or degree of light used, whe- 
ther the full solar rays, or bright or dull daylight ; since in the former case the inten- 
sity of the middle part of the spectrum enormously exceeds and overpowers that of 
every other part, while in the latter cases it is only in a slight degree brighter. 

In Part II. § 2, the author gives the dispersion formula substantially the same as 
M. Cauchy's, as far as the 4th power of X. He adopts a method of calculation by 
means of least squares, and considers the verification sufficient, from the agreement 
in one specimen of Fraunhofer's flint-glass. 

It cannot but excite surprise to find so eminent a philosopher at the present day 



TRANSACTIONS OP THE SECTIONS. 9 

referring to the ideal analogy of musical intervals. Yet Newton's notion of the 
permanency of the proportions in the analysis of light might seem but the necessary 
consequence of the permanence of the synthetic result. And this main difficulty 
yet remains to be cleared up. 

The Abbe Moigno has also referred more particularly to this subject in his 
' Repertoire d'Optique Moderne' (Paris, 1847, vol. i. p. 123-126). After giving 
M. Cauchy's formula, he states that in my comparisons of observation and theory 
for a great number of media the differences never exceeded the probable errors of ob- 
servation.. Unfortunately not only is this not the case, but I have expressly dwelt 
upon it, in reference to one or two most highly dispersive substances. He also ob- 
serves, that M. Cauchy (in his ' Nouveaux Exercices ') has re-calculated the results, 
and shown a perfect accordance. But this applies only to Fraunhofer's ten media, 
and does not extend to the highly dispersive oils. He further states the deduction 
from M. Cauchy's formula, that the differences of the squares of velocities of pro- 
pagation are very nearly as the reciprocals of the squares of the wave-lengths ; but 
adduces only one case of flint-glass in proof. It seems to be often overlooked, that 
though there is a close accordance for all moderately dispersive substances, yet a 
very few instances to the contrary in the higher part of the scale suffice to show that 
the formula stands in need of some essential modification to make it apply to them, 
■while it shall still include the former. I have pointed out* that an empirical con- 
stant for each medium will rectify the discordance. Whether this can be justified by 
theory, is the point to which the attention of mathematicians ought I think now to 
be directed. 

Both M. Mossotti and M. Moigno admit the necessity of assuming (according 
to the number of terms taken) three or four experimental constants for the medium. 
I notice this, because it has been objected to in my investigations. But on distinct 
grounds it appears to me evident that from the nature of the problem we must suppose 
at least three constants to characterize each medium. In other words, the problem is 
a compound one, each medium having as it were three distinct properties : — 1st, the 
absolute magnitude of its refraction, or deviation of the whole spectrum or of a mean 
ray ; 2nd, the magnitude of dispersion, or expansion of the whole ; 3rd, the cha- 
rctcter of the dispersion or relative expansion of the parts : conditions which are 
certainly independent of each other, and each of which would involve a separate 
constant. 

On Irradiation. By the Rev. Prof. Powell, F.R.S. ^c. 

The phsenomenon known by the name of Irradiation is best exhibited by the me- 
thod of M. Plateau, which forms the basis of all the author's experiments, and 
which consists of a card or lamina cut so that a long paral- 
^ ^«tiijsfij jifiait^^ lelogram has one half cut out and the other left, the por- 
tions at the sides being cut away. Thus the effect is seen 
doubled either by transmitted or reflected light. [In the 
annexed sketch the shaded portions represent the parts cut 
away.] It is well established that the effect increases with 
Lfli the intensity of the light. It is also evident that it decreases 

Bj rapidly towards the edge of the enlarged surface. 

Jffi| The effect has been ascribed by most writers to a peculiar 

kind of physiological afl"ection of the retina. But (allowing 
for the effects of dazzling, contrast, &c.) the author has shown that this is not the 
case, since exactly the same effect is produced in an artificial eye, or camera obscura. 
The eflfect has also been tried photographically, in some cases especially in direct sun- 
light, with perfect success ; in others without effect. But the most effective photo- 
graphic rays are not the most illuminating, and may therefore not be equally subject 
to this modification. 

These phaenomena appear to be simply cases of the enlarged focal image of a lu- 
minous point, which is a well-known result, both of theory, as investigated by Mr. 
Airyf, and of observation, as seen in the discs of fixed stars under contracted aper- 
tures. 

* Treatise on Dispersion, &c., p. 119. t Camb. Trans, v. 283. 







10 REPORT — 1849. 

The effect on the eye is diminished, and may be totally destroj'ed, by the inter- 
vention of a lens, even in the brightest lights. This is explained by the diminution 
of intensity in proportion to the superficial magnification, which is most effective at 
the edges. 

In telescopes there is a twofold effect of this kind, one at the focus of the eye, 
another at that of the object-glass ; the former may be neutralized by the magnifi- 
cation of the eye-piece. The author has tried many experiments on the image of a 
card, cut as above, seen in a telescope under apertures of various degrees of con- 
traction, which appear to accord closely with the phsenomena of " the diffraction of 
the object-glass." It also follows that there must be a limit to the increase of 
the enlargement of the image, dependent on the diminution of light when the 
aperture is contracted beyond a certain point, which will vary in each individual 
instrument. 

The author suggests a method of measuring the amount of irradiation under any 
given conditions of light, by viewing and measuring micrometrically in a telescope 
the image of a card cut as above, under the given light, placed at the focus of an 
object-glass opposite to that of the telescope, and connected with it by a tube. 

Theoretically, irradiation would explain those singular phfenomena seen in eclipses 
and transits of the planets, of the connection of the edge of the dark disc bj- necks 
or threads to that of the sun ; as also the apparent projection of a star on the bright 
limb of the moon, by simply overlapping the star from irradiation. But the difficulty 
in all these phrenomena is their appearance in some cases and not in others, under 
circumstances apparently similar. 

On a Mode of Measuring the Astigmatism of a Defective Eye, 
By Professor Stokes, M,A. 

Besides the common defects of long sight and short sight, there exists a defect, 
not very uncommon, which consists in the eye's refracting the rays of light with 
different power in different planes, so that the eye, regarded as an optical instrument, 
is not symmetrical about its axis. This defect was first noticed by the present 
Astronomer Royal, in a paper published about twenty years ago in the Transac- 
tions of the Cambridge Philosophical Society. It may be detected by making a 
small pin-hole in a card, which is to be moved from close to the eye to arm's length, 
the eye meanwhile being directed to the sky, or any bright object of sufficient size. 
With ordinary eyes the indistinct image of the hole remains circular at all distances ; 
but to an eye. having this peculiar defect it becomes elongated, and, when the card 
is at a certain distance, passes into a straight line. On further removing the card, 
the image becomes elongated in a perpendicular direction, and finally, if the eye be 
not too long-sighted, passes into a straight line perpetidicular to the former. Mr. 
Airy has corrected the defect in his own case by means of a spherico-cylindrical 
lens, in which the required curvature of the cylindrical surface was calculated by 
means of the distances of the card from the eye when the two focal lines were 
formed. Others however have found a difficulty in preventing the eye from altering 
its state of adaptation during the measurement of the distances. The author has 
constructed an instrument for determining the nature of the required lens, which is 
based on the following proposition : — 

Conceive a lens ground with two cylindrical surfaces of equal radius, one con- 
cave and the other convex, with their axes crossed at right angles ; call such a lens 
an ast'ujmatic lens ; let the reciprocal of its focal length in one of the principal planes 
be called its power, and a line parallel to the axis of the convex surface its astig- 
matic axis. Then, if two thin astigmatic lenses be combined with their axes inclined 
at any angle, they will be equivalent to a third astigmatic lens, determined by the 
following construction : — Through any point draw two straight lines, representing 
in magnitude the powers of the respective lenses, and inclined to a fixed line drawn 
arbitrarily in a direction perpendicular to the axis of vision at angles equal to twice 
the inclinations of their astigmatic axes, and complete the parallelogram. Then the 
two lenses will be equivalent to a single astigmatic lens, represented by the diagonal 
of the parallelogram in the same way in which the single lenses are represented by 
the sides. A piano-cylindrical or spherico-cylindrical lens is equivalent to a common 



TRAXSACTIONS OP THE SECTIONS. II 

lens, the power of which is equal to the semi-sum of the reciprocals of the focal 
lengths in the two principal planes, combined with an astigmatic lens, the power of 
which is equal to their semi-difference. 

If two plano-cyhndrical lenses of equal radius, one concave and the other convex, 
be fixed, one in the lid and the other in the body of a small round wooden box, with 
a hole in the top and bottom, so as to be as nearly as possible in contact, the lenses 
will neutralize each other when the axes of the surfaces are parallel ; and, by merely 
turning the lid round, an astigmatic lens may be formed of a power varj'ing con- 
tinuously from zero to twice the astigmatic power of either lens. When a person 
who has the defect in question has turned the lid till the power suits his eye, an 
extremely simple numerical calculation, the data for which are furnished by the 
chord of double the angle through which the lid has been turned, enables him to 
calculate the curvature of the cylindrical surface of a lens for a pair of spectacles 
which will correct the defect of his eye. 

On the Deternmiation of the Wave Length corresponding with any point of 
the Spectrum. By Professor Stokes, M.A. 

Mr. Stokes said it was well known to all engaged in optical researches that Fraun- 
hofer had most accurately measured the wave lengths of seven of the principal fixed 
lines in the solar spectrum. Now, he found that by a very simple species of inter- 
polation, w^hich he described, he could find the wave lengths for any point interme- 
diate between two of them. He then exemplified the accuracy to be obtained by his 
method by applying it to the actually known points, and showed that in these far 
larger intervals than he ever required to apply the method to the error was only in 
the eighth, and in one case in the seventh place of decimals. By introducing a term 
depending on the square into the interpolation still greater accuracy was attainable. 
The mode of interpolation proposed depended upon the known fact, that, if sub- 
stances of extremely high refractive power be excepted, the increment A//, of the re- 
fractive index in passing from one point of the spectrum to another is nearly pro- 
portional to the increment AA-2 of the squared reciprocal of the wave length. Even 
in the case of flint-glass, the substance usually employed in the prismatic analysis 
of light, this law is nearly true for the whole spectrum, and will be all but exact if 
restricted to the small interval between two consecutive standsird fixed lines. Hence 
we have only to consider ^ts as a function, not of A, but of A-^, and then take pro- 
portional parts. 

On examining in this way Fraunhofer's indices for flint-glass, it appeared that 
the wave length (B>i) of the fixed line B was too great by about 4 in the last, or 
eighth, place of decimals. It is remarkable that the line B was not included |in 
Fraunhofer's second and more accurate determination of the wave lengths, and that 
the proposed correction to (Bx) is about the same, both as to sign and magnitude, 
as one would have guessed from Fraunhofer's own corrections of the other wave 
lengths, obtained from his second series of observations. 



On Professor Quetelet's Investigations relating to the Electricity of the Atmo- 
sphere, made with Peltier's Electrometer. Communicated by Professor 

WlIEATSTONE, F.R.S. 

Of all the meteorological conditions of the atmosphere its electrical state is per- 
haps among the most important. Yet in the various observatories established in 
different parts of the world in connexion with the great magnetic inquiry now in 
progress, and in the establishment of which the British Association has taken so 
prominent a part, no provision has been made for regular observations relating to 
this important subject. It thus happens, that while we possess a most valuable ac- 
cumulation of periodical records, made with great accuracy and regularity at widely 
different points of the earth's surface, relating to the magnetism of the earth, and 
to the barometric, thermometric, hygrometric, and anemometric conditions of the 
atmosphere, we have no simultaneous electrical observations with which to compare 
them. 



] 2 REPORT — 1849. 

This has arisen from the want of a simple and efficient instrument by which such 
observations could be made. The most valuable results which have hitherto been 
obtained have been made with fixed electric apparatus. That established at the 
Observator)' of the British Association at Kew, under the superintendence of Mr. 
Ronalds, and in which he has introduced so many important improvements which 
render it, in perfectness of insulation, and the comparability of its attached electro- 
meters, superior to any hitherto erected, will no doubt, when the observations 
made at the establishment during the past five years are reduced and discussed, as 
is now being done by Mr. Birt, yield valuable results. Still such apparatus are 
too costly, and require too many precautions in their establishment and manipula- 
tion to be recommended for general use. 

Meteorologists will therefore learn with satisfaction that this deficiency is now 
supplied by the late M. Peltier's induction electrometer, a portable instrument, 
simple in its construction, certain in its results, and of which any number may be 
made perfectly comparable with each other. One of these instruments is on the 
table. A hollow ball of copper, four inches in diameter, is placed at the top of a 
rod of the same metal, which is terminated at its lower extremity by a much smaller 
ball. From the last-mentioned ball, insulated from the glass cover by a lump of 
shell-lac, descends a copper rod, which bifurcates and forms a kind of ring. At the 
centre of this ring a small copper needle, which forms the essential part of the in- 
strument, moves freely, balanced on a pivot. When the electrometer is in its na- 
tural state, the needle is brought to the magnetic meridian by a much smaller mag- 
netic needle which is parallel to it, and fixed immediately above it. Another copper 
needle, much thicker than the moveable one, forms a system with the rod which 
descends into a glass tube filled with shell-lac and fixed into the wooden stand. 
Thus the entire metallic part of the apparatus is insulated, and electricity can be 
communicated from it neither to the glass cover nor the stand. This insulation 
mu.=t be established with the greatest care. The stand is furnished with three level- 
ing screws, which enables it to be placed horizontally. To prepare the instrument 
for an observation, it must be so placed that the fixed needle shall be in the direc- 
tion of the magnetic meridian. In this position, the moveable needle, directed by 
its small magnetic needle, places itself parallel to the fixed needle. If now a body 
electrified, positively or negatively, be held above the ball, it decomposes by induc- 
tion the electricity of this ball and its metallic appendages. If the body be posi- 
tively electrified, at the upper extremity of the ball the negative electricity is coerced 
by the positive electricity in presence, while in the lower part of the instrument the 
free positive electricity causes the small needle to diverge from the position which it 
had at first, and its angle of deviation from the fixed needle will be greater as the 
free electricity is more considerable. The angle of deviation is read off by means of 
two graduated circles, one of which is pasted to the stand and the other to the 
glass cover ; by this parallax is avoided in the readings. If while the ball is in- 
fluenced by the external electricity, the stem is touched, the free electricity, which 
we will assume to be positive, will be removed and the needle will replace itself in the 
magnetic meridian. If the inducing body which coerces the negative electricity at 
the upper part of the ball be removed immediately after, this electricity will become 
free, and the moveable needle will diverge anew. 

I will state in M. Peltier's own words the mode of operating with this instrument 
when the electricity of the air is to be observed. " When I wish to ascertain the 
electric tension accumulated in the atmosphere, I ascend to the terrace, I place the 
instrument on a stand raised about G feet, I put it in equilibrium by touching the 
lower part of the stem, I then descend, and place the instrument on the table ap- 
propriated to it : all this is performed with great rapidit}', and requires only eight 
seconds : when the instrument is put in equilibrium, the arm of the observer must 
be raised as little as possible, for if it be raised sufliciently to reach the globe, the 
hand becoming negative by induction will repel the negative electricity of the ball ; 
it will neutralize the positive portion which will be attracted towards it, and the 
instrument will be charged negatively at the moment of the removal of the hand. 
The stem must therefore be touched as low as possible, and with as slender a body 
as a metallic wire, in order to avoid the inductive action of the mass of the hand 
upon the remainder of the stem. The equilibrium being established when it is 



TRANSACTIONS OP THE SECTIONS. 13 

elevated at any height above the surface, the instrument on being lowered gives 
signs of negative electricity, while on being raised it will indicate positive. When 
the operation is thus performed, this change of sign must be taken into consideration, 
in order not to attribute a contrary electricity to the atmosphere. In like manner 
a negative tension of the atmosphere is indicated, when the instrument after de- 
scending into the cabinet gives a positive sign." 

The proportional forces corresponding to the marked degrees of Peltier's electro- 
meter may be ascertained in two ways. Peltier has given a table, in which the equi- 
valent degrees were determined by an electric torsion-balance ; but the method 
employed} by Quetelet is more easily applicable, and gives very satisfactory and 
comparable results. This method, which is that of Volta, consists in dividing the 
electric charges by placing spheres of the same diameter in contact. He took 
two electrometers, each surmounted by a metallic ball of the same diameter ; he 
commenced by charging the first electrometer so that the needle indicated 74°"5, 
the two balls were then placed in contact to divide the charge. After this first 
operation the electrometer indicated only 70°. Their values, according to Peltier's 
table, correspond to 2825° and 1400° of the torsion-balance, which corresponds 
almost exactly with the ratio of 2 : 1. After having discharged the second electro- 
meter, he again placed it in contact with the first, which this time only indi- 
cated 64°, or 795° of the table of equivalents, which is nearly half of the number 
1400. This operation was repeated several times in succession in order to form 
the table. 

A regular and uninterrupted series of observations has been made with this in- 
strument by M. Quetelet at the Royal Observatory in Brussels since the beginning 
of August 1844. He has recently published these observations, extending through 
four and a half years, from this date till the 31st of December 1848, and the con- 
sequences he has deduced from them are very satisfactory and important. I will 
briefly state the principal of these results, referring for more extended details to the 
last memoir he has published on the climate of Belgium *. 

The first object of M. Quetelet was to ascertain the relation that exists, under 
ordinary circumstances, between the dilFerent heights above the neutral point and 
the electric intensities. The experiments of Erman and Saussure had long since 
made known that electricity is not equally expanded in the atmosphere ; that it is 
nearly of the same intensity in a horizontal stratum of air, and stronger in the 
upper strata. The discussion of the numerous experiments made by M. Quetelet 
with respect to this point, shows that in a place in the neighbourhood of which 
there are no higher objects, the electric intensity of the air increases, starting from 
a determinate point, proportionally to the height. But it must be borne in mind 
that this law has only been verified with respect to heights not exceeding 16 feet. 

The observations, with the view of ascertaining the annual variations of atmo- 
spheric electricity, were made every day at about the hour of noon, commencing in 
August 1844. The results of each year are in complete concordance, and are as 
follows : — 1st. The atmospheric electricity, considered in a general manner, attains 
its maximum in January, and progressively decreases till the month of June, which 
presents a minimum of intensity ; it augments during the following months till the 
end of the year. 2ndly. The maximum and the minimum of the year have for their 
respective values 605 and 47 ; so that the electricity in January is thirteen times 
more energetic than in the month of June. The mean value of the year is repre- 
sented by the values given by the months of March and November. 3rd. The 
absolute maxima and minima of each month follow a course precisely analogous to 
that of the monthly means ; the means of these extreme terms equally produce the 
annual variation, although in a less decided manner. 

In order to determine the intensity of the electricity of the air in its relations with 
the state of the sky, M. Quetelet separated, for each month of the year, the num- 
bers which referred to a sky entirely clouded, from those observed when the sky 
was serene, or rather presenting so few clouds that eight- or nine-tenths were at 
least entirely unclouded. In order not to complicate the results by foreign influ- 
ences, he omitted the observations made during storms, snow, rain and fogs. The 
table thus formed gave the following results : — 1st. Whatever be the state of the sky, 

* Annales de rObservatoire Royale de Bnixelles, torn, vii. 1849. 



14 



REPORT— 1849. 



the electricity of the air presents a maximum in January and a minimum towards 
the summer solstice. 2ndly. The ditference between the maximum and the mini- 
mum is much more sensible in serene than in cloudy weather. In the latter case the 
numbers are 268 and 36, the ratio of which is about 7. In serene weather the 
maximum of January is 1133° and the minimum of July 35°; the ratio of these 
numbers is 36, which shows a very considerable difference. 3rdly. Throughout every 
month the electricity of the air is stronger when the sky is serene than when it is 
clouded, except towards the months of June and July, when the electricity attains 
a minimum, the value of which is nearly the same whatever be the state of the sky. 
Starting from this epoch, the electricity of the air, when the sky is clear, exceeds 
the electricity observed when the sky is entirely clouded, in proportion as the months 
advance towards January, when the ratio is more than 4 to 1. This strong elec- 
tric intensity, under a clear sky in winter, is a very remarkable circumstance, and 
had already been noticed by all the investigators of atmospheric electricity, although 
they attributed to it a much less relative value. 

Monthly variations in the Electricity of the Air. 





1844. 


1845. 


1846. 


1847. 


1848, 


Mean. 


January 

February ... 

March 

April 

May 

June 


90 

91 

110 

127 

340 


471 

548 

262 

93 

163 

51 

58 

89 

95 

299 

334 

742 


562 

256 

95 

94 

49 

39 

33 

57 

62 

98 

274 

799 


957 

413 

282 

221 

67 

47 

43 

11 

39 

107 

160 

356 


487 

295 

164 

155 

59 

48 

61 

64 

63 

120 

152 

281 


605 

378 

200 

141 

84 

47 

49 

62 

70 

131 

209 

507 


July 

August 

September... 

October 

November ... 
December ... 


4nnual mean 


... 


267 


202 


225 


162 


206 



Electricity of the Air in relation to the state of the 


Sky. 








J. 


F. 


M. 


A. 


M. 


J. 


J. 


A. 


S. 


0. 


N. 


D. 


Clouded sky... 
Clear sky 


268 
1133 


220 
493 


129 
261 


71 
149 


46 
63 


36 
37 


41 
35 


56 
64 


42 
78 


75 
168 


109 
226 


181 
571 



M. Quetelet has united in a special table the observations made during extraor- 
dinary circumstances, such as fogs, snow showers and rain, and which he did not 
employ in the calculation of the means. From this table he has obtained the fol- 
lowing results :■ — The mean of the electric intensity observed during fogs is almost 
exactly the same value as that observed during snow showers ; this value is very 
high, and corresponds to the mean maxima observed for the first and last months 
of the year. It does not appear that it is influenced by the seasons. The values 
observed during tranquil rain do not differ much from the ordinary values observed 
during the course of the year. In some circumstances a strong electricity, either 
positive or negative, has been observed at the approach or cessation of rain. During 
the four years included in M. Quetelet's register, the electricity at the ordinary hour 
of observation was observed to be negative only twenty-three times ; and he remarks 
that it was only observed to be negative once during the four months of October, 
November, December and January. These negative electric indications in general 
precede or follow rain and storms; they are thus distributed: the electricity has 
been observed to be negative six times during rain, nine times before rain, five times 
after rain, twice during rain falling in distant places, once without apparent cause. 



TRANSACTIONS OP THE SECTIONS. 15 

From the observatioas made to ascertain the diurnal variation of the electricity of 
the air, M. Quetelet deduces the following conclusions : — 1st. The electricity of the 
air, estimated always at the same height, undergoes a diurnal variation, which gene- 
rally presents two maxima and two minima. 2ndly. The maxima and minima vary 
according to the different periods of the year. 3rdly. The first maximum occurs, in 
summer, before eight o'clock in the morning, and towards ten o'clock in winter ; the 
second maximum is observed after nine o'clock in the evening in summer, and to- 
wards six o'clock in winter. The interval of time which separates the two maxima 
is therefore more than thirteen hours at the epoch of the summer solstice, and eight 
hours only at the winter solstice. 4thly. The minimum of the day presents itself 
towards three o'clock in the summer, and towards one o'clock in winter. The ob- 
servations were insufBcient to establish the progress of the night maximum. 5th. 
The instant which best represents the mean electric state of the day, in the different 
seasons, occurs about eleven o'clock in the morning. 

The indications afforded by Peltier's electrometer are simpler and more readily in- 
terpreted than atmospheric electrometers of the usual construction. The former is 
affected only by the inductive action of the atmosphere, or rather by the difference 
of the inductive actions of the earth and its superincumbent atmosphere ; however 
the instrument be raised above or depressed below its'point of equilibrium, or how- 
ever the inductive action of the atmosphere may change, while it remains in the same 
position it neither receives nor loses any electricity ; its distribution only is changed. 
But if instead of a polished ball the stem be terminated with a point, a bundle of 
points, or a lighted wick, as in Volta's experiments, to the pha;nomenon of induc- 
tion there is added another which complicates and sometimes disguises it ; the un- 
coerced electricity radiates into space, and though this radiation is greater as the in- 
duction is more powerful, yet it is also greatly influenced by the moisture of the 
air, rain, and the force of the wind, none of which circumstances affect in any obvious 
degree the induction electrometer. 



On Shooting Stars. By W. R. Birt. 

See Reports in this volume, page 1 . 



Meteorological Phcenomena observed in India from January to May 1849. 
JBy George Buist, LL.D., F.R.S. (Communicated by Colonel Sykes.) 

The papers comprised pressure curves of the barometer for five years at Boml)ay, 
four years at Madras, and four years at Calcutta; a map of the occurrence of 
storms at various places in India between the 19th and 25th of April L849 ; corre- 
sponding observations at various places during storms in India on the 15th and 
22nd of January ; the same between the 20th and 23rd of February and the 1st and 
3rd of May. The pressure of papers in the Section disabled Colonel Sykes from 
giving more than a running commentary upon the different phsenomena. He called 
the attention of the Section to the general uniformity of the several pressure curves 
at the three presidencies in India ; the maximum pressure being in December or 
January, and the minimum pressure in June or July ; the absolute height of the 
barometer however was different in different years ; but the gradual descent of the 
curve from January to June and ascent from June to January was rarely inter- 
rupted, excepting at Bombay in the months of September and October 1845 and 
1846; in the months of August and September, at Madras, in 1841 ; and in No- 
vember and December 1843 and 1844. At Calcutta the descent and ascent of the 
curves did not show any interruption, but the barometer appeared to have a greater 
annual range at Calcutta than at Bombay or Madras. Colonel Sykes called atten- 
tion to the fact that these curves were not affected by the passage of the sun twice 
annually over the places of observation, nor by the occurrence of the monsoon at 
Calcutta and Bombay in June, and at Madras in October. The map of storms be- 
tween the 19th and 24th of April, showed that they occurred almost simultaneously 
in the Punjab, near Wuzeerabad, at Loodiana, at Simla, Delhi, Calpee, Alahabad, 
Calcutta, Bombay, Belgaum, Madras, and down the coast to Tranquebar ; at Man- 
galpre, and down the Malabar coast to Cochin, and on the western side of Ceylon. 



16 REPORT — 1849. 

Accompanying this map. Dr. Buist gave curves of horary oscillations from the 19th 
to the 25th of April at Bombay, Madras, Aden, Calcutta, Lucknow and Mangalore, 
and at none of these places were the daily oscillations of the atmosphere, with their 
two maxima and two minima, in the slightest degree interrupted ; and with refer- 
ence to the uniformity of these horary oscillations and the annual maximum and 
minimum pressure. Colonel Sykes called the attention of the Section to the singular 
coincidence of these movements of the atmosphere; with similar movements, tt 
nearly the same hours and periods, of the electric intensity, as determined by Mr. 
Birt in a paper recently read by him in the Section. In the storms of the 15th and 
22nd of January, 20th to 23rd of February, and 1st to 3rd of May, Dr. Buist gives 
the simultaneous reading of the maximum and minimum pressure of the barometer 
at various places. These readings show that the horary oscillation at places on 
the level of the sea may have different ranges ; for instance, at Calcutta and Bombay, 
on the 18th and 19th of February, the horary oscillation at Bombay is respec- 
tively 0*104 and 0"132, and at Calcutta 0'159 and 0'165. Carrying the comparison 
to Aden, the discrepancy is yet greater — 0'072 and O^OSl. Similar instances occur 
at the other periods. In the meteorological crisis of the 15th of January, Dr. Buist 
considered that the storm was felt all over India ; and amongst other places, where 
it fell severely, he mentions Jaunah in the Deccan, where, on the 14th of January 
1849, there was a hail-storm, the hailstones being lenticular, and from two to two 
and a half inches in diameter, and weighing from one to two ounces each ! On the 
whole. Dr. Buist is of opinion that meteorological disturbances extend over very 
considerable areas. Dr. Buist's papers were not accompanied by tables of tempe- 
rature or moisture. 

On a Rainbow seen after actual Stmset. By the Rev. Prof. Chevallier. 

The rainbow was seen at Esh, six miles west of Durham. The latitude of the 
place, determined by Bessel's method of observing the transits of stars over the 
eastern and western prime vertical, is 54° 47' 25" ; and its longitude 6" 45' west. 
The elevation above the sea is /OO feet. The time of the setting of the sun's upper 
limb could not be observed, in consequence of clouds ; but the computed time, allow- 
ing 33' for the horizontal refraction, was 8'' 36'" 2'. At 8'' 31"' 43' the bow seemed 
to be a portion of an arc greater than a semicircle, approaching to the form of a Sa- 
racenic arch, both sides being visible to an elevation of about 40°. At 8'> 34" 43' 
the southern end had faded ; but at the northern end the primary and secondary 
bow were both visible at an altitude of about 5°, the sky being sensibly darker be- 
tween the two bows. This northern end of the rainbow continued visible until 
gh 37"' 48'^ or 1'" 42' after complete sunset ; and at %'^ 38"" 43', or 2'" 41' after sun- 
set, an irregular portion of the southern part of the bow was visible at an altitude 
of about 15°. 

The time was accurately obtained by comparing the watch with a transit-clock 
immediately after the observation. The barometer at the time, at the Observatory 
at Durham, 34 7 feet above the level of the sea, stood at 29'48, the attached ther- 
mometer 61°, the external thermometer 57°'5, the wind S.W., force 4. In order 
to account for this appearance, it seems necessary to suppose either that the hori- 
zontal refraction was much greater than its ordinary value, or that the rainbow was 
formed in a very elevated region of the atmosphere. 



Notices of Mirage on the Sea Coast of Lancashire. By T. Hopkins. 

In this paper Mr. Hopkins represented that he had observed the phaenomenon 
called Mirage on certain parts of the sea coast of Lancashire, and had at different 
times examined the state of the atmosphere on various parts of the shore, but more 
particularly near Southport. Here he found that whilst the sky was cloudy, ap- 
parently threatening rain, evaporation in the air near the surface of the wet shore 
was very active ; but at other times, when the sun was shining brightly, evaporation 
at the same short distance from the surface was checked or entirely stopped, and at 
such times mirage might be seen. 

On the morning of July 9th mirage appeared at a certain distance to the north of 



TRANSACTIONS OP THE SECTIONS. 17 

the spectator over the flat sandy shore, and on examining the state of the locality 
where the phaenomenon had been seen, the following facts were ascertained : — 
The temperature on the adjoining dry sand-hills was 87° 
on the moist sand of the flat shore 78°" 1 

of a dry-bulb thermometer in air ... 65°"5 
of a wet-bulb thermometer in air ... 63°'6 

Difference between the two last 1°'9 

To account for these facts, Mr. Hopkins said that when mirage appeared the sun 
was shining brightly, and by his direct rays raised the temperature of the ground 
considerably, when energetic evaporation from the wet sandy shore took place, 
which sent much vapour into the atmosphere. The presence of this vapour in the 
air checked evaporation from the wet- bulb thermometer, and prevented it from be- 
coming much cooled, and the wet-bulb thermometer at the same time, by the feeble- 
ness of its evaporation, proved the existence of the large amount of vapour in the 
locality. Now as mirage appeared only when the sun produced a large amount of 
vapour from the moist surface of the ground, which vapour was shown to be present 
by the state of the wet-bulb thermometer, it is to be inferred that the vapour caused 
the appearance of mirage. 

It might be that some of the vapour was condensed by the comparatively cool air, 
at a small distance from the surface of the sand, and thus a stratum of cloud was 
formed from the surface of which light was reflected. But however this may be, the 
presence of vapour sufficient to saturate or nearly saturate the air in the part always 
accompanied the appearance of the mirage, and therefore is presumed to be the 
cause of it. Objects that were beyond the place where the mirage appeared were 
reflected by it as if they were reflected by water. Refraction sometimes accompa- 
nies mirage, distorting the reflected as well as other objects, nearer to the spectator 
than the mirage ; but the refraction is quite a separate phtenomenon, sometimes 
appearing with and sometimes without the mirage. 

Mr. Hopkins exhibited a number of tabulated observations in corroboration of 
what had been advanced. He also said that recently, at Blackpool, in the middle 
of the day, with a clear sky and a strong sun, while the dry- and wet-bulb thermo- 
meters on the wet sandy shore were at the same height (70°), there was a difference 
of 5° between the two instruments on the adjoining cliflFs, about sixteen yards high. 
These facts, Mr. Hopkins contended, proved, that while evaporation saturated the 
air near the surface and produced mirage, the atmosphere at the height named was 
comparatively dry, allowing evaporation to take place with considerable energy from 
the wet-bulb thermometer. 

Letter from Sir Robert H. Inglis, Bart.., F.R.S., to Col. Sabine, JR.A., 
Aug. 8, 1849. 
We were at Gais (Canton Appenzell, Switzerland) a few days ago, and saw 
there, what may be familiar to you and other men of science, but was quite new to 
me and to the people at the place. About 3 p.m. on the 8th of August my servant 
called to me, " that there was something falling very curious." I went out — to the 
bridge which connects the old and new buildings of the Hotel du Boeuf, — and under 
the shade of the new house looked up and saw thousands and thousands of brilliant 
white motes, like snow, falling as in flakes. There were no clouds, but there was 
a kind of halo round the sun, or rather, as I looked up, there were in that direction 
apparently more and larger masses through which the rays passed ; balls separated 
themselves, consisting of vast numbers, and these resolved themselves into frag- 
ments and came whirling and floating about. The master of the Hotel, M. Heen, 
joined us : he had obviously never seen anything of the kind before, and called out, 
" Des millions, des millions." He summoned his people to look. I continued to 
gaze till I was half-blinded. At first the fragments seemed to melt ; and to the 
last I could distinguish no appearance of an animal. Our servant fancied that he 
saw something like wings ; I certainly looked till, to my eye, they seemed to evapo- 
rate, but their disappearance and perhaps the re-appearance of the same individual, 
might have been owing to their turning at right angles instead of exhibiting their 
extent lengthways, and «;fce versa. This lasted — at least Hooked — 25 minutes. Cer- 
184.9. 2 



IS REPORT — 1849. 

tainly none came to the ground. Reaumur 20°, no wind. Gais is 3100 feet above 
the sea. 

Of analogous facts (more or less so) Sir John F. W. Herschel, Bart. F.R.S., says, 
in a letter to Col. Sabine, R.A., I can mention two : — 

1. In or about the year J 821, I remember seeing in Sir James South's telescope 
at Blackmat) Street, when turned in a direction near, but not to the sun, about 
midday, frequent objects having all the appearance of stars, which were seen sailing 
through the field of the telescope. Dr. Wollaston, when this was mentioned to 
him, said it was thistledown. I do not think it was. 

2. In the hay season, some three or four years ago, the day being clear and hot 
and calm (at least in the immediate neighbourhood of our house), our attention was 
excited by what at first seemed to be strange -looking birds flying; but though pre- 
sentlj' assured they were not birds, it was by no means clear what they were. They 
were irregular wispy masses sailing leisurely up and settling down again, apparently 
over a hay- field on the east of our grounds, and above a quarter or three-eighths of 
a mile from our house. Some of these were of considerable size, and their general 
appearance was convex downwards and taily upwards. After wondering awhile, I 
got a telescope and directed it to the flying phsenomenon, when it became evident 
that they were masses of hay — some of very considerable size, certainly not less 
(allowing for the distance) than a yard or two in diameter. They sailed above 
leisurely, and were very numerous. No doubt wind prevailed at the spot, but 
there was no roaring noise, nor any sign of a whirlwind, and all about us was quite 
calm. Nobody was at the time at work in that field. None fell on our side of the 
trees, above tvhich they rose perhaps 50 or 100 feet. 

P.S. Could Sir R. Ingiis's phsenomenon have been winged ants ? They some- 
times appear in astonishing numbers, and might associate like gnats in masses for 
a dance, and then separate again. 

On Meteorological Observations made at Kaqfjord, near Alien, in Western 
Finmark, and at Christiania in Norway. By John Lee, LL.D., F.R.S., 
of Hartioell, Bucks. 

Dr. Lee stated that he had the honour to present to the Association some meteo- 
rological observations, made by Mr. J. H. Grewe, an officer in the service of the 
Alten Mining Company at Kaafjord, in Western Finmark, near Alten, under the 
direction of S. H.Thomas, Esq., the superintendent and able geologist of the Company, 
for the months of January to September inclusive of 1848 ; and that they had been 
made at the same hours of the daj^ and on the same plan as the similar observations 
which he had the pleasure to present to the Association in former years. 

The present observations were accompanied by two new Tables from Mr. Grewe; 
the first containing barometrical means, deduced from the period of eleven years, 
and arranged in three series: — 1st, the monthly means; 2nd the quarterly means; 
3rd, the annual means. The second table contained the thermometrical means, made 
simultaneously with those of the barometer, and arranged in similar series. These 
observations and tables of Mr. Grewe were also accompanied by two tables made by 
Mr. J. F. Cole, a gentleman now resident in London, but formerly at Alten, and 
the associate of Mr. Grewe in making some of the earlier observations at Kaafjord; 
and Mr. Cole has reduced the observations of Mr. Grewe from the French measures 
to Fahrenheit's scale ; and Dr. Lee produced a letter addressed to him by Mr. Cole, 
explanatory of the tables. 

Dr. Lee also presented to the Association, through the courtesy of J. R. Crowe, 
Esq., Her Britannic Majesty's Consul- General of Norway, a series of meteorological 
observations, made during the year 1848 at Christiania. They were stated to be a 
continuation of observations made at the same hours and on the same plan as others 
presented on former years. ,p , 

(L.opy.; London, 8th September 1849. 

Sir, — I have had much pleasure in inspecting the Alten Meteorological Observa- 
tions from January to September 1848, lately transmitted to you by my former 
colleague, Mr. Grewe. 

It appears that from October 1848 the hours of observation have been changed 



TRANSACTIONS OP THE SECTIONS. 19 

from 9 A.M., 3 p.m. and 9 p.m. to 7 and 11 a.m., 3, 7 and 10 p.m., in accordance 
with the suggestion of Professor Hansteen of Christiania. 

The present observations are the last of a set of eleven years, and Mr. Grewe has 
formed a very interesting table of the results of the barometer and thermometer for 
that time ; some of these results I have reduced into English scales, as per tables 
annexed. 

From the table of the results of the observations on the barometer for the eleven 
years ending 30th September 1848, it will be perceived that the means of the 9 p.m. 
observations are higher than those of 9 a.m. and 3 p.m., except in November and 
December, when the 3 p.m. are a trifle the highest. 

The observations fall from 9 a.m. to 3 p.m., and then rise to 9 p.m. The monthly 
means fall from May to June and July, and rise to August, then fall to September, 
October, November and December, and rise to January, then fall to the lowest mean 
in February, and rise to March and April, reaching the highest mean in May. 

During the eleven years the month of May gives the highest monthly mean, and 
the month of February the lowest. 

The mean of the monthly means for May and February (being the highest and 
lowest) differs from that of the eleven years by only 0"017615 inch; but of the 
monthly means, the one for March comes nearest to that of the eleven years, differ- 
ing by only 0-00079 inch. 

Of the seasons, the mean for Spring is the highest and Autumn the lowest. The means 
fall from Spring to Summer and Autumn, and rise from Autumn to Winter and Spring. 

From the tables of the results of the observations on the thermometer for the 
eleven years ending 30th September 1848, it will be found that the means of the 
9 p.m. observations are lower than the 9 a.m. and 3 p.m. without exception. Of the 
eleven years, the month of February is the coldest, and August the warmest. 

The monthly means of the observations rise from March to August, both inclusive, 
and from September to February, also both inclusive. 

The monthly means rise thus : — o 

From February to March, Fahrenheit. 5*336 

From March to April, Fahrenheit 9'536 

From April to May, Fahrenheit 9"396 

From May to June, Fahrenheit 8-807 

From June to July, Fahrenheit 6-651 

From July to August, Fahrenheit 0-254 

Total rise 39-980 

They then fall— o 

From August to September, Fahrenheit 10721 

From September to October, Fahrenheit 12-522 

From October to November, Fahrenheit 7'873 

From November to December, Fahrenheit 2-855 

From December to January, Fahrenheit 3-368 

From January to February, Fahrenheit 2-641 

Total fall 39-980 

It will be noticed from the foregoing, that the monthly means rise rapidly from 
March to June, and fall heavily from August to November. 

The mean of the monthly means for August and February being the highest 
and lowest, differs from that of the eleven years by only 1^-594 Fahrenheit. 

The nearest monthly mean to that of the eleven years is October, differing from 
it by only l°-659 Fahrenheit ; this agrees with the result generally noticed by me- 
teorologists. 
The means of the seasons : — o 

Fall from Summer to Autumn 25*785 Fahrenheit 

Fall from Autumn to Winter 7'879 „ 

And rise from Winter to Spring 21-413 „ 

And rise from Spring to Summer 12-251 „ 

I remain. Sir, 

Your obedient humble Servant, 
(Signed) John Francis Cole. 
2* 



20 



REPORT — 1849. 



Results of Eleven Years' Observations on the Barometer, made at Alten Copper 
Works, Norway, from October 1837 to September 1848, reduced to English inches. 



Bfonths. 


g A.M. 


3 P.M. 


9 P.M. 


Monthly Means. 


No. of 

obsen'a- 

tions. 


Mean 

height 

for eleven 

jears. 


No. of 
observa- 
tions. 


Mean 

height 

for eleven 

years. 


No. of 
observa- 
tions. 


Mean 

height 

for eleven 

years. 


No. of 
observa- 
tions. 


Mean 

height 

for eleven 

years. 




339 
310 
340 
320 
339 
328 
332 
326 
323 
341 
326 
333 


29-70683 
29-64738 
29-75187 
29-85671 
29-88730 


338 
310 
339 
319 
S.S8 


29-71329 
29-64733 
2975061 
29-84931 
29-89254 
29-79860 
29-77155 
29-79864 
29-76372 
29-69262 
29-67029 
29-66549 


339 
310 
339 
319 
339 
330 
331 
326 
325 
340 
327 
331 


29-71726 
29-65770 
29-75986 
29-86112 
29-89683 
29-81092 
29-78856 
29-81734 
29-78081 
29-70549 
2966667 
29-66329 


1,016 
930 

1,018 
958 

1,016 


29-71246 

29-65281 
29-75411 
29-85573 
29-89222 








Mav 




29-79892 330 
29-78301 334 
29-80809 3->S 


980 29-80281 
997 29-78104 
980 29-80801 


Julv 






29-76844 
29-69707 
29-66604 
29-65872 


325 
338 
327 
331 


973 

1,019 

980 

995 


29-77100 
29-69841 
29-66766 
29-66250 










Mean of eleven 1 


3957 


29-75254 


3957 


29-75167 


3956 


29-76049 


11,870 


29-75490 





Seasons. 


9 A.M. 


3 P.M. 


9 P.M. 


Quarterly Means. 


No. of 
observa- 
tions. 


Blean 
lieight 
for the 
season. 


No. of 
observa- 
tions. 


Mean 
height 
for the 
season. 


No. of 
observa- 
tions. 


Mean 
height 
for the 
season. 


No. of 
observa- 
tions. 


Mean 
height 
for the 
season. 




987 

981 

1000 

989 


29-84766 
29-78652 
29-67396 
29-70203 


987 
987 
996 
987 


29-84683 
29-77797 
29-67612 
29-70573 


988 
982 
998 

988 


29-85628 
29-79557 
29-67848 
29-71159 


2,962 
2,950 
2,994 
2,964 


29-85026 
29-78667 
29-67620 
29-70644 


Summer 








Mean of eleven 1 
years J 


3957 


2a-75254 


3957 


29-75167 


3956 


29-76049 


11,870 


29-75490 









Years. 


Annual Means, 


No. of 

observations 

during the 

year. 


Mean height 
for the year. 


1837 to 1838 

1838 — 1839 

1839 — 1840 

1840 — 1841 

1841 — 1842 

1842 — 1843 

1843 — 1844 

1844 — 1845 

1845 — 1846 

1846 — 1847 

1847 — 1848 


1,045 
1,095 
1,083 
1,064 
1,087 
1,095 
1,098 
1,095 
1,089 
1,068 
1,051 


29-82400 
29-74573 
29-77490 
29-81833 
29-74179 
28-69510 
29-76557 
29-78242 
29-70372 
29-78573 
29-73659 


Mean of eleven years... 


11,870 


29-75490 



TRANSACTIONS OF THE SECTIONS. 



21 



Barometrical Means, deduced from a series of Eleven Years' Observations, made at 

Kaafjord in West Finmark, latitude 69° 67', longitude 23° 2' east of Greenwich. 

Table I.— Monthly Means. 



No. of 
observa- 
tions. 



No. of 
Barometer, observa- 
I tions. 



Barometer. 



No. of 
observa- 
tions. 



Barometer 



No. of ] 
observa- Barometer, 
tions. I 



Monthly Means. 



January .. 
February.. 

March 

April 

May 

June 

July 

August .. 
September 
October .. 
November 
December 



339 
310 
340 
320 
339 
328 
332 
326 
323 
341 
326 
333 



754-555 
753-045 
755-699 
758-362 
759139 
756-894 
756-490 
757-127 
756-120 
754-307 
753-519 
753-333 



338 
310 
339 
319 
338 
330 
334 
328 
325 
338 
327 
331 



754-719 
753-196 
755-667 
758-174 
759272 
756-886 
756199 
756-887 
756-000 
754-194 
753-627 
753-505 



339 
310 
339 
319 
339 
330 
331 
326 
325 
340 
327 
331 



754-820 
753-307 
755-902 
758-474 
759-381 
757-199 
756-631 
757362 
756-434 
754-521 
753-535 
753-449 



1,016 
930 

1,018 
958 

1,016 
988 
997 
980 
973 

1,019 
980 
995 



754 6.98 
753 183 
755-756 
758-337 
759-264 
756-993 
756-440 
757-125 
756-185 
754-341 
753-560 
753-429 



No. of Obs. and"! 
Means of 11 yrs. J 



3957 



755-716 



3957 



755-694 



3956 



755-918 



11,870 



755-776 







Table 


I. — Quarterly Means. 








Seasons. 


9 A.M. 


3 P.M. 


9 P.M. 


Quarterly Means. 


No. of 
observa- 
tions. 


Barometer. 


No. of 
observa- 
tions. 


Barometer. 


No. of 
observa- 
tions. 


Barometer. 


No. of 
observa- 
tions. 


Barometer. 




987 

981 

1000 

989 


758-132 
756-579 
753-720 
754-433 


987 
987 
996 
987 


758-111 
756-362 
753-775 
754-527 


988 
982 
998 
988 


758-351 
756-809 
753-835 
754-676 


2,962 
2,950 
2,994 
2,964 


758-198 
756-583 
753-777 
754-545 




Autumn 


Winter 


No. of Obs. and "1 
Means of 11 yrs. J 


3957 


755-716 


3957 


755-694 


3956 


1 
755-918 11,870 


755-776 







Table 


[II. — Annual IMeans. 








Years. 


9 A.M. 


3 


P.M. 


9 P.M. 


Annual Means. 


No. of 




No. of 




No. of 




No. of 






observa- 


Barometer. 


observa- 




observa- 


Barometer. 


observa- 


Barometer. 




tions. 




tions. 




tions. 




tions. 




1837 to 1838 


349 


757-309 


349 


757-526 


347 


757-758 


1,045 


757531 


1838 — 1839 


365 


755-387 


365 


755-583 


365 


755-659 


1,095 


755-543 


1839 — 1840 


361 


756-234 


362 


756-240 


360 


756-378 


1,083 


756-284 


1840 — 1841 


356 


757-389 


354 


757-320 


354 


757-452 


1,064 


757-387 


1841 — 1842 


362 


755-265 


363 


755-403 


362 


755-661 


1,087 


755-443 


1842 — 1843 


365 


754-204 


365 


754-192 


365 


754-374 


1,095 


754-257 


1843 — 1844 


366 


754-269 


360 


754-123 


366 


754-414 


1,098 


754-269 


1844 — 1845 


365 


756-445 


365 


756-402 


365 


756-576 


1,095 


756-475 


1845 — 1846 


363 


754-488 


362 


754-348 


364 


754-593 


1,089 


754-476 


1846 — 1847 


357 


756-587 


355 


756-402 


356 


756-689 


1,068 


756-559 


1847 — 1848 


348 


755-297 


351 


755-094 


352 


755-543 


1,051 


755-311 


No. of Obs. and"! 
Meansof llyrs. J 


3957 


755-716 


3957 


755-694 


3956 


755-918 


11,870 


755-776 



The observations are separately corrected for the temperature of the mercury, capillarity 
and error of the scale, and reduced to the freezing point, at the level of the sea high-water 
mark. The series commenced on the 1st of October 1837, and concluded on the 30th of 
September 1848, both inclusive. 



22 



REPORT 1849. 



Results of Eleven Years' Observations on the Thermometer, made at Alten Copper 
Works, Norway, from September 1837 to September 1848, reduced to Fahren- 
heit's Scale. 



Months. 


9 A.M. 


3 P.M. 


9E 


.M. 


Monthly Means. 


No. of 
observa. 
tions. 


Mean 

height 

for eleven 

years. 


No. of 
observa- 
tions. 


Mean 

height 

for eleven 

years. 


No. of 
observa- 
tions. 


Afean 

height 

for eleven 

years. 


No. of 
observa- 
tions. 


Mean 

height 

for eleven 

years. 




339 
310 
340 
320 
339 
328 
332 
326 
323 
;i41 
326 
333 


18°-554 
15498 
20-908 
31-912 
41-212 
49-366 
56-185 
56-379 
45-185 
32099 
24-850 
21-897 


338 
310 
339 
319 
338 
330 
334 
328 
325 
338 
327 
331 


19-099 
16-795 
23-371 
33012 
42213 
51-359 
58-262 
58-950 
47-307 
33-922 
24-985 
21-952 


339 
310 
339 
319 
339 
330 
331 
326 
325 
340 
327 
331 


17-902 
15341 
19-360 
27-322 
37009 
46-132 
52-362 
52245 
42-919 
31-822 
24-390 
21-807 


1,016 
930 

1,018 
958 

1,016 
988 
997 
980 
973 

1,019 
980 
995 


18°518 
15-877 
21-213 
30-749 
40145 
48-952 
55-603 
55-857 
45-136 
32-614 
24-741 
21-886 












July 














i 


Mean of eleven \ 
years J 


3957 


34-504 


3957 


35-935 


3956 


32-383 11,870 


34-273 



Seasons. 


9 A.M. 


3 P.M. 


9 P.M. 


Quarterly Means. 


No. of 
observa- 
tions. 


Mean 
height for 
the season. 


No. of 
obser^'a- 
tions. 


Mean 
height for 
the season. 


No. of 
observa- 
tions. 


Mean 
height for 
the season. 


No. of 
observa- 
tions. 


Mean 
height for 
the season. 




987 

981 

1000 

989 


40-829 
52 583 
26-283 
18-320 


987 
987 
996 
987 


42-195 
54-840 
26-953 
19-755 


988 

982 
998 
988 


36-820 
49-176 
26006 
17-533 


2,962 
2,950 
2,994 
2,964 


39949 
52-200 
26415 
18-536 






Winter 


Mean of eleven] 


3957 


34-504 


3957 


35-935 


3956 


32-383 


11,870 


34-273 





Years. 


Annual Means. 


No. of 

obsenations 

during the 

year. 


Mean height 
for the year. 


From Oct. to Sept. 

1837 — 1838 

1838 — 1839 

1839 — 1840 

1840 — 1841 

1841 — 1842 

1842 — 1843 

1843 — 1844 

1844 — 1845 

1845 — 1846 

1846 — 1847 

1847 — 1848 


1,045 
1,095 
1,083 
1,064 
1,087 
1,095 
1,098 
1,095 
1,089 
1,063 
1.051 


32-016 
33-028 
36-050 
33-872 
35-013 
33-508 
35-161 
33-841 
35-033 
35-476 
34018 


Mean of eleven years... 


11,870 


34-273 



TRANSACTIONS OF THE SECTIONS. 



23 



Thermometrical Means, deduced from a series of Eleven Years' Observations, made 
at KaaQord in West Fiamark. latitude 69° 57', longitude 23° 2' east of 
Greenwich. 

Table I.— Monthly Means. 



January ... 
February... 

March 

April 

May 

June 

July 

August .. 
September 
October .. 
November 
December 



Means of eleven years. 



- 7-470 

- 9-168 
_ 6-162 

- 0049 
+ 5-118 
+ 9-648 
+13-436 
+ 13-544 
+ 7-325 
+ 0-055 

- 3-972 

- 5-613 



+ 1-391 



- 7-167 

- 8-447 

- 4-794 
+ 562 
+ 5-674 
+ 10-755 
+ 14-590 
+ 14-972 
+ 8-504 
+ 1068 

- 3-897 

- 5-582 



+ 2-186 



- 7-832 

- 9-255 

- 7-022 

- 2-599 
+ 2-783 
-1- 7-851 
+ 11-312 
+ 11-247 
+ 6-066 

- 0099 

- 4-228 

- 5-663 



+ 0-213 



Monthly 
Means. 



- 7-490 

- 8-957 

- 5-993 

- 0695 
+ 4-525 
+ 9-418 
+ 13-113 
+ 13-254 
+ 7-298 
+ 0-341 

- 4-033 

- 5-619 



+ 1-263 



Table II.— Quarterly Means. 



Seasons. 


9 A.M. 


3 P.M. 


9 P.M. 


Quarterly 

Means. 




+ 4-905 
+ 11-435 
- 3-176 
_ 7-600 


+ 5-664 
+ 12-689 
_ 2 804 
_ 6-803 


+2-678 
+9-542 
-3-330 
-8-037 


+ 4-416 
+ 11-222 
- 3103 

_ 7-480 






"Winter 


Means of eleven years.. 


+ 1-391 


+ 2-186 


+0-213 


+ 1-263 



Table III.— Annual Means. 



Years. 


9 A.M. 


3 P.M. 


9 P.M. 


Annual 
Means. 


1837 to 1838 

1838 — 1839 

1839 — 1840 

1840 — 1841 

1841 — 1842 

1842 — 1843 

1843 — 1844 

1844 — 1845 

1845 — 1846 

1846 — 1847 

1847 — 1848 


+0-808 
+ 0-979 
+ 2-162 
+ 1-059 
+ 1-719 
+0-874 
+1-709 
+ 1-095 
+ 1-892 
+2054 
+0-948 


+0-737 
+ 1-522 
+3-188 
+ 1-860 
+2-518 
+1-726 
+2-806 
+2-021 
+2-616 
+3-180 
+1-876 


-1-516 

-0-789 
+ 1-400 
+0-200 
+0-785 
-00S6 
+0-753 
-0-046 
+0-547 
+0-558 
+0-539 


+0-009 
+0571 
+2-250 
+ 1 040 
+1-674 
+0-838 
+ 1-756 
+ 1-023 
+ 1-685 
+ 1931 
+ 1-121 


Means of eleven years . 


+1-391 


+2-186 


. +0-213 


+1-263 



The thermometrical observations were made simultaneously with t^2?,^/^;, *Jf^^^" 
meter. Each observation is separately corrected for the error of ^^r^l^- ^ J^^ ^^/^T.S i^ 
in the shade stood about three feet above the ground. The scale m Centigrade degrees is 
graduated on the glass tube. 



24 REPORT — 1849. 

On the Cleans of Computing the Quantity of Vapour contained ifi a Vertical 
Column of the Atmosphere. By T. Hopkins. 

Mr. Hopkins showed that the quantitj^ of aqueous vapour existing in the atmo- ' 
sphere is computed, by meteorologists of the present day, from the tension of vapour] 
near the surface of the globe in such a way as would be correct if an atmosphere of' 
vapour only existed. But the vapour in our atmosphere is intermixed with and 
diffused through gases, which gases cool by expansion consequent on the removal 
of incumbent pressure five times as much as the vapour does. The vapour therefore 
produced by evaporation at the surface of the globe, as it passes into the higher 
regions of the atmospheric space, is cooled and condensed, not by its own law of 
cooling by expansion, but by the cold of the gases ; and the result is that a smaller 
quantity of vapour remains in the atmospheric column with a given temperature 
and dew-point at the surface than there would be in a pure vapour atmosphere, or 
than is now said to be indicated by the tension of the vapour found at the suiface. 
That tension he showed was a consequence, not alone of the pressure of an incum- 
bent column of vapour, but also of the resistance which rising vapour encounters 
from having to penetrate the gases while expanding upwards into the atmospheric 
space. As soon as elastic vapour is formed the surface of the globe becomes the 
base on which it rests, and from which it is disposed to expand upwards. But the 
resistance of the gases prevents free expansion, and preserves a certain amount of 
density of vapour that would not otherwise be so early attained. The tension of 
vapour therefore only measures the degree of density that is thus produced, and 
does not indicate correctly the quantity that exists in the whole atmospheric column. 
Tables were exhibited by Mr. Hopkins to show (he quantities of vapour, expressed 
in decimal parts of an inch of mercury, that could exist at different heights to the 
extent of 4000 yards from the surface, in an atmosphere of pure vapour, and also in 
our mixed atmosphere, each being at the temperature and dew-point of 50° at the 
surface. And the excess in the quantity of vapour in the former above the latter 
was stated to show the extent of the error involved in the present mode of estimating 
the quantity of vapour in a vertical column of the atmosphere with the dew-point 
named, 50°. 

On Meteors. By Edward Joseph Lowe, F.R.A.S. 
See Reports in this volume, page I. 

Notice of a Meteor seen in India on the I9th of last March. 
By Admiral Sir C. Malcolm. 

This consisted of selected notices of the meteor from the Bombay 'Times of March 
and April, and contained several letters detailing the circumstances under which it 
■was seen by the different writers — from which it was inferred to be a mass of over 
600 feet in diameter ; and the place at which it fell after bursting was ascertained 
to a high degree of probability : it fortunately was not an inhabited place. 

Extract from the Bombay Times, March 16, 1849. 

We have letters from Hoshungabad to the 6th inst., which mention that most 
extraordinary weather had prevailed there during the latter half of February. It 
had been close, hazy and drv, and a similar state of matters prevailed up to the 
day above mentioned. On the evening of the 5th the clouds began to collect, the 
atmosphere having been highly charged with electricity for four days previous, — the 
electrometer (Cavallo's) readily indicating the amount, and the least friction causing 
considerable excitation. Pressure and dryness had somewhat increased, and rain 
was therefore not looked for, but either another earthquake or a thunder-and-dust 
storm was predicted by the weather-wise. On the 2C)th of February half a gale 
had blown throughout the greater part of the day, the mean of the barometer ha- 
ving descended in three days from 29"949 to 29'(JS4 ! Our correspondent continues : 
" Prognosticating an earthquake at Hoshungabad is somewhat akin to a pig see- 
ing the wind ; but I only hint at such a phaenomenon from the consciousness that 



TRANSACTIONS OF THE SECTIONS. 25 

there is something very peculiar just now in the atmosphere, and from the fact that 
the instruments seem as strangely siifected as the senses." 

We adverted in a former issue to the singular state of the weather at Calcutta, 
Delhi, along the line of the Jhelum and Chenaub from Rhotas to Mooltan, and near 
Socotra at Aden, on the 22nd of January ; and we now have an account of the ap- 
pearance at Gibraltar at the same date of nearly the same phasnomena which were 
observed all over the northern part of India. Here, as at Calcutta, Bombay, and 
Aden, the mercury was remarkable for its elevation ; and we have little doubt that 
were returns obtained from the intermediate points, similar facts would be supplied. 
Here we have one of the most striking cases of an atmospherical perturbation of 
simultaneous occurrence we have ever noticed, traceable over one-fourth part of the 
earth's circumference from east to west, and 20° lat. N. by S. We now have the same 
striking chain of phsenomena from Ceylon, where the heat at Colombo in the last 
week of January was altogether without precedent in the meteorological annals of 
the Cinnamon Isle. Hot winds, resembling those of the present year, were last 
experienced in 1844 [month not given], when they blew from the I6th to the 19th, 
occasioning much injury to the crops. The waters of the Colombo lake were be- 
ginning to dry up, and the canals were nearly useless ; many of the wells had run 
dry. The Ceylon Times, to which we are indebted for these facts, assures us that 
the evaporation amounts to nearly an inch per diem. 



On the Results of certain Anemotrieters. By Follett Osler. 

The author first stated, that, from an aggregate of upwards ot 50,000 additional 
hourly observations, he had been enabled to test the accuracy of the report he brought 
forward in Glasgow respecting the hourly forces of the wind and their coincidence 
with the curves of temperature, and that the result was highly satisfactory, being 
almost precisely similar to that recorded in the report just alluded to, the wind 
rising with the temperature with great regularity. The curve of temperature for 
each season corresponded with the curve of force ; but from these observations it 
would appear that the period of mean force in the evening took place about half an 
hour before that of mean temperature; showing that the motion of the air declines 
more rapidly than the temperature. The whole of the stations comprise an aggre- 
gate of nearly 200,000 hourly observations, all of which were tabulated and reduced. 
The direction of the wind for each hour of the day, together with its force, was first 
tabulated, and from this an abstract was obtained, giving the total force and direc- 
tion for every day. Thus, on the first of January for each year the winds for that 
day with their forces are recorded ; and so on throughout the year. By thus ob- 
taining the exact period of each wind, the coincidences of a series of years were 
ascertained. In reviewing the Wrottesley observations, which were carried out 
more fully than the rest, Mr. Osier called attention to the fact of disturbances in the 
currents of the atmosphere taking place at certain and apparently regular intervals. 
A comparative calm is followed by considerable disturbances : these calms and 
movements appear to be periodical. It was possible that observations for a longer 
term might neutralize these periods, and by shifting their times only leave us with 
the knowledge that intermittent pulses do occur ; but the regularity of some led him 
to hope that such is not the case, and that a law of periodicity might be traced even 
in this variable climate. 

From six years' records at Wrottesley the average periods of greatest movement 
in the aerial currents took place towards the end of Januarj-, the middle and end of 
March, the end of April, the early part of June, a short time after the middle of 
October, about the 20th of November, and the first week in December : the periods 
of greatest calm occurred about the middle of January, about the 17th of June, and 
about the 14th of November. There were many other maxima and minima, but 
Mr. Osier thought it desirable to defer going more into detail respecting them until 
he had been able further to investigate the subject. On minutely examining the 
registers of the anemometers two kinds of currents are observed, the one moving very 
regularly and with great steadiness, the other in larger pulses or waves, causing the 
vane to oscillate over a considerable arc. One he regarded as the air moving to fill 
up a void or deficiency ; the other, flowing from an excess or from a portion of the 



26 REPORT — 1849. 

atmosphere, being put in motion and carried on by momentum previously acquired, 
causing great undulations in its motion, on which occasions the wind appears to 
have much more force than is really indicated by an instrument. The north winds 
generally showed less oscillation than those from the south points. While carrying 
on these observations, Mr. Osier's attention had occasionally been directed to par- 
ticular storms, and he had applied to them the rotatory theory set forth by Colonel 
■Reid, in the main principles of which he fully agreed; but he considered that a 
rotating circle would not explain all the changes that occur. He was of opinion 
that the rotating portion is smaller than has usually been assumed, and that the 
air approaches this circle or vortex in spiral lines ; that sometimes this rotating 
circlf is not in contact with the earth, in which case the lower current will be more 
in the direction of radial lines ; that the air in advance of a storm is not put into 
such rapid motion in consequence of the movement forward of the storm itself, while, 
for the same reason, the action in the rear of the storm is increased. 

Mr. Osier called the attention of the Section to the great practical importance of 
endeavouring to ascertain the exact course of the wind in rotatory storms, which he 
considered miiht be done with the aid of the instruments we now possess. The 
Americans were beginning to take the subject up in a manner worthy of its import- 
ance; and Mr. Osier hoped that while Lieut. Mauiy and others were at work on 
the west coast of the Atlantic we should take the east. He recommended that a 
series of stations for meteorological observations be established, commencing at the 
Canaries and including Madeira and Gibraltar, the west coast of Spain and Portugal, 
the Azores, Guernsey, &c. In England, Ireland and Scotland many stations are 
already established that would no doubt join in contributing observations. By 
adopting a well-organized and comprehensive system, the main currents on the east 
of the Atlantic might soon be ascertained vs;ith great exactness. 

Mr. Osier then exhibited and described his improved integrating anemometer. A 
plain sheet of paper, about twelve inches wide, and long enough to last some weeks 
(or months if required), is first rolled on a cylinder whose axis is horizontal, and 
passing over a second cylinder is received on to a third. Over the central cylinder is 
placed a registering pencil. The second and central cylinder is made to revolve in 
proportion to the rate at which the air is passing, by means of rotators exposed to 
the atmosphere. The direction is obtained by the same means that Mr. Osier 
adopted with the anemometer at Lloyd's, and which is found to act with great 
exactness, laying down the direction in a single line free from all oscillations. This 
is accomplished by means of a fan-sail, similar to that at the back of a windmill, 
the motion from which is conveyed to a pencil. The paper is ruled as it passes on, 
by means of pencils indicating the direction. The time is recorded by a clock, 
which causes a series of small punches marked with the hour to be brought round 
in succession, one of which receives a blow every hour from the hammer of the 
clock, and records it on the margin of the paper. Thus a single line gives the di- 
rection and quantity of air passing any station, while every hour the clock marks 
off the time. Mr. Osier pointed out some improvements he had made in his original 
pressure anemometer, by which he was now enabled to record the force of even 
light winds at the same time the instrument was strong enough to resist storms. 
In conclusion, Mr. Osier said that he had long been impressed with the conviction, 
that if greater attention were paid to a study of the currents of the atmosphere, it 
would prove to be of more importance in advancing the science of meteorology than 
anything else that has hitherto been done. It was this conviction that led him to 
construct his first anemometer in 1836 ; and though he was not so sanguine as to 
expect to see meteorology vie with astronomy in its mathematical prophecies, yet he 
believed that if the subject were taken up on a systematic plan for a short period 
the results might prove of very great value to science. 



On the Temperature of the British Isles, aiid its influence on the Distribution 
of Plants, By Augustus Petermann, F.R.G.S. 

The author adverted to the climate of Western Europe as being the mildest, 
comparatively, of all countries in a similar latitude, and showed that a temperate 
zone, limited by the isothermals of 70° and 30° (Fahr.), extended in 



TRANSACTIONS OF THE SECTIONS. 27 

North America from 30° to 51° N. lat. 

Asia 30°... 50° ... 

Europe 30°... 71° ... 

The British Isles are situated almost in the centre of this zone. To show the main 
features of their temperature, the author had constructed on a large map iso- 
thermals of the hottest and coldest month (July and January) in the year, based oa 
the observations of about seventy places. 

The most striking feature in the January isothermah is their general direction 
from north to south, instead of from west to east, inferring the greatest cold not in 
the north, but in the east. Between the Shetland Isles and the southern coast of 
England (except Cornwall and Devon) there is no difference in the winter tempera- 
ture ; but between the eastern coasts of England and the western coasts of Ireland 
the difference amounts to about 10°; the former being, at an average, 35°, the latter 
probably 45°. The coldest portion of Britain extends from the Naze to the Firth of 
Forth, comprising to the west all the Pennine chain ; in this district an average 
temperature of 35° to 36° prevails. On the continent the January temperature be- 
comes lower in going eastward, precisely in the same ratio as in the British Isles, 
and the isothermal of 28° extends as far west as the meridian of Gottingen and 
Hanover. In Scandinavia the temperature decreases very suddenly, owing to the 
snow-clad mountain masses which project in a high rampart on the western coasts. 
The difference between Bergen and Christiania, two places in about the same lati- 
tude, distant from each other IQO miles, amounts to as much as 14°, the former 
being 35°"0, the latter 20°'8. The author then proceeded to allude to general and 
local causes, by which these January' isothermals are regulated. 

The average direction of the isothermals of the hottest month (July) is from S.W. 
to N.E. The highest summer temperature in the British Isles, indicated by the 
isothermal of C4°, occurs in the central portion of the south coast of England, the 
lowest in the N.W. part of Scotland, and the difference appears to be at least 10° j 
while the difference between the western and eastern coasts is much less. The iso- 
thermal of 62° extends to Lincoln, Birmingham, and the southernmost ponions of 
Wales. All Ireland, Wales, northern part of England, and Scotland to the foot of 
the Highlands, lie between the isothermals of 62° and 60°. North of the Highlands 
the temperature is very considerably lower, Inverness having only 55°'7. By com- 
paring the British Isles with parts of the continent in the same latitude, we find in 
that of Dublin, 6l°-5, at the Dutch shores 64°, at Hamburg 65°. In the latitude 
of Inverness (55°'7 temp.), Frederikshaven in Denmark 6l°'9, Goteburg in Sweden 
63°"2 ; between this latter place and Inverness the distance is 6()0 English miles. 

The author then alluded to the influence of temperature on the distribution of 
plants, the districts of which he had found to be strikingly corroborative with the 
general correctness of his isothermals (for his botanical observations he was greatly, 
indebted to Mr. H. C. Watson, author of the ' Cybele Britannica,' &c.). There are 
altogether a good number of plants in Britain which botanists are accustomed to re- 
gard as western species, being frequently scattered along the western counties, from 
Cornwall to Scotland, without passing into the eastern counties, unless at the south 
or north extremities of Britain. Compared with each other, these western species 
present much diflFerence in respect to the area, or space of Britain, over which they 
are distributed respectively. But they correspond in the negative peculiarity of being 
absent from that part of Britain which extends between the Firth of Forth and the 
Lincolnshire Wash, and mostly absent from the whole eastern side of the island be- 
tween the Thames and Murray Firth. This class of plants corresponds in their di- 
stricts with the January isothermals. Other plants, less impatient of a cold winter, 
but requiring a higher summer temperature, are found to run parallel with the July 
isothermals. A great number of species, and the districts where they occur, were 
named. Among the more important plants being limited by summer isothermals is 
the vine, the northern limit of which is found to be between the July isothermals of 
66° and 67°. In the valley of the Seine, it obtains its highest latitude between Louvier 
and Andelys in about 49° north lat., but further east, near Berlin, it reaches nearly 
52^°, a latitude corresponding with that of Norwich, Birmingham and Limerick. 

The author, in concluding his observations, expressed the hope to see this subject 
further investigated ; especially to see the net of meteorological stations over the 



28 REPORT — 1849. 

British Isles extended and completed, — all Ireland and Wales, as well as the north- 
western part of Scotland, exhibiting as yet great blanks on an isothermal map. 



0—i 



Contributions to Anemometry — The Therm-anemometer. By John Phillips, 
F.R.S., Assistant- General Secretary to the British Association. 

The author's researches into the force and velocity of wind have been directed to 
the completion of a method of wind-registration which should be independent of 
mechanical movements, momentum and friction *. He wished to register the wind 
by one of the effects of the displacement of its molecules, not the movement of its 
mass. For this purpose only one method has occurred to him as sufficiently appli- 
cable, viz. the evaporation of a liquid. He has experimented on water, saline 
solutions and alcoholic mixtures, and he finds that with either of these liquids an 
instrument really indicating the movement of wind, by the registration of the eva- 
poration which the wind causes, is producible. Such an instrument 
need occupy but a very small space, and will have the desirable quality 
of being most accurate in those very low velocities of wind which elude 
entirely Lind's anemometer, and are scarcely sensible by any register- 
ing machinery. 

It will be remembered, that for the interpretation of the register of 
evaporation into a register of wind velocity, it was necessary first to 
correct for the hygrometric state of the air. This being done, the cooling power of 
wind was found by experiment to be nearly as the square root of its velocity. In 
this experimental result Professor Phillips was induced to place confidence, because 
it appeared to represent and flow naturally from what may be thought the true phy- 
sical action of the moving air. 

Having lately occasion to examine extensively and carefully into the amount of 
air which passes through the ramified passages of collieries, where the currents are 
sometimes so slow, that machine anemometers, even of a most delicate description, 
are insensible to the movement of the air — where even the miner's candle affords but 
a rude guess, and where the situation is such that smoke or the powder flash can- 
not be appealed to — he was happy to find that the problem was perfectly and easily 
solved, by noting the cooling power of the current. 

For this purpose a registering or integrating anemometer is not required. The 
currents underground are steady, and require only an anemoscope or indicator of 
the momentary velocity. Evaporation from the wet-bulb may therefore be aban- 
doned ; the common thermometer, with its bulb clear of the frame, will answer the 
purpose of experiment in every conceivable instance f. 

The author stated the general formula, to which he had been conducted by very 
numerous experiments through a large range of velocities ascertained bv other means, 

thus : -- — r=iv. 

In this formula C and r are constants to be determined for the particular ther- 
mometer in use ; s being the number of seconds which elapse in cooling through a 
certain range (5°) from a point a certain number of degrees (10°) above the tempe- 
rature of the moving air, v the movement of air in a given time (one second). 

The explanation is simple. A thermometer-bulb, heated above the temperature 
of the surrounding air, is cooled by radiation and by convection. 

Omitting at present the consideration of the cooling in the fhermometer-bulb by 
radiation (?•). the effect of air movement in lowering temperature is proportional to 
the quantity of air {q) (or number of cooling elements) which passes the bulb, and to 
the time of its action (s), or to qs, which will be a constant (C) for each instrument. 
The quantity which passes is proportional to the velocity of the current, and to the 

Q 

time of its action, or q=:vs. Hence C = q s^vs^, and v = —. 

* Reports on Anemometry, 1846, p. 340; 1848, p. 97. 

tit appears from Prof. Forbes's Report on Meteorology to the British Association in 
1832, that the idea of employing a thermometer for indicating the velocity of wind was en- 
tertained by Professor LesUe. It appears never to have been worked out. — (J. P.) 



TRANSACTIONS OF THE SECTIONS. 29 

By a great variety of experiments, r, the effect of radiation, is quite unimportant 
in practice (less than half a foot in a sec.:;nd), except in very low velocities. Its 
effect in combination appears to be constant for the same instrument, and precisely 
similar to that of v, so as to be included v\'ith it. The formula thus becomes 

C C 
» + »•= ^ or -p— »• = «'• 

As already stated, he had made frequent and advantageous use of this cooling pro- 
perty of the air for measuring its velocity in coal-mines. In these situations it is 
perhaps the only accurate method which can be applied to determine the quantity of 
air which passes through the extremities of the workings — by the bodies of the work- 
men engaged in cutting the coal — at particular and critical outlets from the old 
wastes — in contractions by brattices, scalings, and perforated doors. In one of the 
most important of these cases, viz. the current of air by the bodies of the workmen 
in the extremities of the ' intake ' system, he found enormous differences in different 
coal districts ; but he forbore to mention them, because statements of this kind, un- 
accompanied with full explanation, might lead to very erroneous conclusions re- 
garding the relative safety and good management of mines, and prejudice important 
inquiries now on foot. 

Professor Phillips found the therm-anemometer equally available in a great variety 
of other researches, some results of which he hoped to present hereafter. 



On Luminous Meteors. By the Rev. Prof. Powell, F.R.S. ^c. 
See Reports in this volume, page 1 . 

Meteorological Observations made at Huggate, Yorkshire. 
By the Rev. T. Rankin. 



On a singular Atmospheric Wave, in February 1849. 
By the Rev. T. Rankin. 



On a Phosphoric Phenomenon in a Pond at Huggate, on June Wth, 1849. 
By the Rev. T. Rankin. 

This communication described minutely, with all the attendant circumstances of 
weather, the state of the barometer and thermometers dry and wet, a violent explo- 
sion of inflammable gas which took place on the above day, accompanied with smoke, 
a great noise, and rumbling concussion, such as to alarm several of the inhabitants 
of the village. The explosion of the gas was propagated along the pond from N.W. 
to S.E. Into this pond the refuse of the village had been for ages draining, and it 
was a common receptacle for the dead bodies of various animals. 



On Magnetized Brass. By the Rev. T. Rankin. 

This communication was for the purpose of recording the fact that Mr. Rankin 
had found the northern half of a brazen meridian of a celestial globe to be so strongly 
magnetic as to deflect a small needle placed near it so much as eight points from its 
true direction ; while the southern part of it seemed to be totally free from magnetism. 



On Observations of the Barometer and Thermometer, made during several 
Ascents in Balloons. By George Rush. 

The results of five ascents are given by the author, viz. from Vauxhall, May 1837, 
4th of September 1838, 10th of September 1838 ; from Leicester, 27th of June 
1849 ; and Norwich, 4th of September 1849. On the second occasion (the balloon 
passing into a snow-storm and rapidly descending) the barometer rose to 19 inches, 
while the thermometer /eW to 22°, being 3° below what it had indicated at the great- 



30 



REPORT 1849. 



est elevation, viz. barometer ]4*70 inches, and 24° lower than when the barometer 
had fallen to 19 inches while ascending, the thermometer then standing at 46°. In 
the last ascent the aneroid barometer was used ; it was found necessary to shake it 
at pressure 2G'50, and it ceased to act at 24*00 pressure. In descending it again 
began to act at 24'50. The following table gives the principal results : 

Temperature of the Upper Regions of the Air corresponding to certain Barometrical 
Heights, as observed by George Rush, Esq., during five balloon ascents. 





Therm. 
May 1837. 


Therm. 


Therm. 


Therm. 


Therm. 




Barometer. 


4th of Sept. 
1338. 


10th of Sept. 
1838. 


27th of June 
1849. 


4th of Sept. 
1849. 


Altitude in feet. 








„ 


^ 






30-50 






60 




74 




3022 














30-00 


60 


66-00 










29-90 








66 






2900 






60 





6800 




28-00 










66 00 




27-00 






58 




65-51 




26-00 


...»•• 




55 




64-50 




25-00 






52 




6300 




24-00 






48 




6100 




23-50 


28 










6553 for 32° fall. 


23-00 




56-00 


46 




6100 




22-40 









'54 






22-00 






'43 




54-00 




21-00 




53-00 


40 




52-46 




20 00 







36 




5200 




19-00 




46-22 


35 




4600 


13,044 for 20' fall. 


18-00 




42-00 


30 








1700 




3900 


25 








1600 




35 00 


20 








1500 




25 00 


18 








14-70 




2500 








19,303 for 41° fall. 


1430 




18-00 


18 






20,352 for 43° fall. 



]^ote. — It has been determined by M. Gay-Lussac, from observations made by him 
during a balloon ascent, in which it is stated that at the temperature of 16° Fahr. 
he attained an altitude of 21,735 feet, the temperature at starting having been 88°, 
that it therefore decreases at the rate of 1° for 352 feet of elevation. 



On Becent Applications of the Wave Principle to the Practical Construction 
of Steam- Vessels. By J. Scott Russell, C.E., F.R.S. 

During the last year I have had more than one opportunity of applying the wave 
principle to the construction of steam-vessels. There is one case, however, in which 
I have been able to apply it to practice under circumstances of greater complexity 
and difficulty than have ever occurred to me, and where it has been successful in 
overcoming difficulties to a greater extent and in a more decided manner than here- 
tofore. The complete success of the principle is no longer to the Members of this 
Association a matter of doubt, especially where its application is not controlled by 
peculiar circumstances. But it will be useful to show, that even in cases where the 
construction is shut up by practical limits and difficulties intractable on ordinary 
rules, the wave principles afford a safe and useful guide. It is also important to 
know at every step how far the experiments made on a small scale are borne out by 
the large, and where the rule is neutralized by the exceptions. 

During the last year a very difficult problem was proposed to me by the engineer 
of a railway company, which required vessels of a very peculiar construction, limited 
by the conditions of the case in such a manner as to be pronounced by some im- 
practicable. It was this, to build a steam-vessel that should be fast without great 
length, a good sea-boat without drawing much water, and to carry a great top weight 



TRANSACTIONS OF THE SECTIONS. 31 

and yet to swim very light. Besides, this vessel was to be able to go backwards as 
well as forwards equally well, and though a small boat was to contain great accom- 
modation. 

Now it will be easily seen by those accustomed to the wave system, that the pro- 
blem as thus stated is one to which the wave principle is far from seeming pecu- 
liarly applicable. In the first place, it is well known that the wave principle pre- 
scribes a different form of the bow for that of the stern, in order to obtain most 
speed with least cost of power. In the second place, it is known that a high speed 
requires, on the wave system, a very considerably greater length than was here al- 
lowed for the entrance of the vessel, or the lines of the bow. It would therefore 
seem at first to be a case that would in all probability prove too difficult for the 
successful application of the wave system. It is on this account mainly that this 
case seems to me important to the science of naval construction, and to the progress 
of the wave system, and to the records of the British Association. 

There is one more feature in the case which gives it interest. At the same time, 
the same problem was worked out by another party on another plan of construction, 
not on the wave principle. Another vessel was built under similar conditions, and 
furnished with engines of the best construction, made by one of the most eminent 
engineers in England. Both these vessels were built at the same time, and tried 
under similar circumstances ; therefore here was a case in which the practical value 
of the wave principle has been brought to a test more direct and less questionable 
than any that was likely to have occurred, and therefore more important to be placed 
on the records of the British Association. 

The first question which will naturally occur to a Member of this Association 
■who recollects this principle, will be this : how could you apply the wave principle 
in a vessel made to go equally well both ways ? The first answer is ready — it is 
this, that the vessel cannot be made to go as fast as if designed with equal power to 
go only one way, seeing that in one case she would have a best possible bow and a 
best possible stern, and in the other case could have neither. 

The next point is this, that in both cases, of bow and of stern, it was necessary 
to have a compromise. Each required to be in turn both bow and stern ; this was 
accomplished in the following manner: — 

If there be any point which has more forcibly struck me in the application of the 
wave principle than another, it is the flexibility of the wave principle — the extent 
to which it admits of deviations from its strict rules without losing the benefit of its 
resistance. If it had unluckily been true of this system, that it prescribed an exact 
mathematical solid in its three dimensions (like Newton's solid of least reaistance;, 
to which implicit adherence was imperative, on pain of losing all the benefit prof- 
fered, then indeed the system would have been (like Newton's) of little use, from 
the fact that from causes independent of resistance, ships cannot be solids of revo- 
lution, consistent with other qualities. The wave principle, on the contrary, pos- 
sesses wonderful flexibility, first from the circumstance of its prescribing lines in one 
plane only, and so leaving the other two dimensions in the hands of the practical 
constructor, so that the sections of the vessel in one plane being given by the system, 
the sections in two others are at the service of the constructor. This to the accom- 
plished constructor is the greatest possible benefit ; to the ignorant constructor it 
may be considered a great disadvantage, because it aflfords him no fixed rule in two 
planes, and so leaves him open to commit a multitude of other errors in points which 
are not questions of resistance ; but to the scientific constructor it gives precisely 
that latitude which he desires, to leave him free to work out the intentions of the 
owners and the uses of the ships he may have to build. 

There is a second point in the wave system, which is another element of its ge- 
neral usefulness — it partakes of the nature of a mathematical maximum or minimum. 
It is the peculiarity of a " maximum and of a minimum," that deviations on either 
side of it to a moderate extent occasion deviations of magnitude that are compara- 
tively very small. Thus it is that the wave line being considered as the curve of 
least resistance, there are near to it an infinite number of approximate curves, which 
are curves of small resistance, though not of least ; and out of these the constructor 
is free to choose those which shall best accomplish any other object, at the sacrifice 
of the smallest amount of resistance. 



32 REPORT — 1849. 

It will readily be seen how these considerations enabled me to obtain in this case 
the greatest amount of benefit out of the application of the wave system. I had in 
this case to lay down for both ends of the vessel, that which is best for a bow, and 
that which is best for a stern, at the given velocity. I had next to place relative 
values on bow resistance and stern resistance. I had next to single out from between 
those two lines, one which taken either as bow or stern would deviate least from 
either, and so have least resistance on a mean of both directions. This therefore the 
wave principle did ; it gave the limits, and gave also the choice of a series of means, 
all more or less suited to the purpose intended. 

I have now shortly to state the practical details by which this process was carried 
into effect, and the results arrived at in consequence. The engines of the vessel, as 
well as the vessel, had to be constructed by my partner P4r. Albert Robinson and 
myself, and we were enabled to adapt the one to the other with greater ease and 
certainty than in all likelihood we could have done had the engineer been separate 
from the ship-builder. In one case the engine was considered and made an actual 
portion of the ship, and the ship of the engine. It will be fair therefore to deduct 
from the good effects attributed to the wave form of the ship such advantages as we 
possessed in building both engines and boilers and ship as one whole. Still it is fair 
to remember, on the other side, that the builders of the engines with which ours had 
to compete have been celebrated for their efficiency and for the large actual power 
they have developed, when compared with their nominal power. It should also be 
remembered that the builders opposed to us had previously built the fastest boats of 
their district. The only advantages which, consistently with right feeling, we could 
venture to claim over our competitors, were therefore the use of the wave system, 
and the having designed both ship, boilers and engines ourselves, and constructed 
them in our own works as one complete whole. 

The practical results obtained are as follows : — 

I. Table of Comparative Experiments. 

Both vessels were about 150-155 feet long. 
22-224 feet beam. 

4 feet draft of water. ^ 
,,, ... 240 tons displacement. 

150 horses' power nominal; 

propelled by oscillating cylinders of 48 inchfes diameter, with the same proportion 
of stroke to paddle-wheel in both cases ; and with only such differences as the engi- 
neers and ship-builders in each case considered likely to be most successful incarrj'- 
ing out the execution of their work to the best advantage ; the terms prescribed to 
both builders by the engineer of the proprietors being identical, and with only such 
latitude as should not form an obstacle to whatever might seem best suited for ob- 
taining greatest efficiency. ^ 

Results of Experiments on Velocity with equal Power. 

Wave Vessel. Competing Vessel. 

Speed. 16'13 miles per hour. 15-03 miles per hour. 

Power ....;. 20*03 velocity of wheel. ]9'09 velocity of wheel. 

Loss 4" 17 slip ^f wheel. 4'87 slip of wheel. 

These are the results of accurate trials at the measured mile, made both with the 
tide and against it. It is important to observe the amount of slip, as it serves to 
show that it was no deficiency of the engine power which caused the difference, both 
engines having gone at as nearly as possible the same speed. A higher speed might 
have been taken for the wave- formed vessel, but this is given as that in which the 
propelling powers were most nearly identical, and therefore the results in speed are 
most directly comparable. 

In order that the statement just given may not lead to false conclusions, it is ne- 
cessary to state what were those minor differences in vessel and engine which each 
constructor adopted as tending to greater efficiency. The wave vessel had a flatter 
floor, five feet longer, and considerably squarer on the midship section; which was 
done for diminishing the depth of water as wanted for her use. In the other vessel. 



TRANSACTIONS OF THE SECTIONS. 33 

the consideration of draft of water was rejected or overlooked, and a finer midship 
section taken, although with a larger draft of water. In one case also the rudders 
were considered as part of the length of the vessel and treated accordingly ; and in 
the other case rejected from it. In the engines, although the diameters of the 
cylinders were identical, the stroke of the wave vessel was somewhat longer than 
the other, but the diminished effective diameter in the shorter stroke reduced them 
to nearly the same proportion. 

Thus far the experiments given only serve to prove that practically a considerably 
better result has been obtained by a steam-vessel built on the wave principle than 
by a competitor built under conditions that are perfectly identical, in so far as the 
public and the owners are concerned. 

But as regards the purely scientific question, I shall add two other experiments 
with the wave vessel, which furnish data of a more permanent and precise nature — 
one at a higher, the other at a lower velocity. 

Table II. — Experiments on the Wave Vessel. 

I. Velocity of vessel 15"14 miles an hour. 

wheel 18-17 

Slip 3-03 

II. Velocity of vessel 16*50 miles an hour. 

tV.' wheel 21-20 

Slip 4-70 

The area of midship section immersed was 89'4 feet. 
The surface of vessel immersed was 3080-0 feet. 
The area of paddle-floats was 26-8 feet. 

The conclusion which I deduce from these last experiments is this, that by means 
of the wave form one may obtain a form of which the resistance shall be repre- 
sented by 1 1 

R = — A. H. S., instead of R = i A. H. S. 
20 6 

which is the lowest number given in any previous system of construction, A being 
the area of midship section, H the height due to the velocity of the vessel, and S the 
1 weight of a cubic foot of water. 

Specimens of Incombustible Cloth. By James Latto, Dundee. 

Specimens of Incombustible Cloth for ladies' and children's dresses, raanufac- 
I tured by Mr. James Latto, Dundee, were exhibited to the Section by Sir David 
I Brewster. This cloth will not catch fire either by a spark or even by contact with 
a lighted candle, or fire to such an extent as to injure the person who wears a dress 
made of it. It burns slowly, with a greenish flame, and is speedily extinguished. 

Rain or washing deprives' the cloth of its diflJcult combustibility, and it was with 
the view of directing the attention of chemists to the subject, so as to discover a 
method of giving the cloth a permanent incombustibility, that Mr. Latto was 
anxious to have his specimens submitted to the Section. 



On Metem-ology considered chiefly in relation to Agriculture. 
By the Rev. Dr. Thomson. 

This was an essay enforcing the importance of meteorological knowledge to those 
engaged in agricultural pursuits, with numerous suggestions as to courses of ob- 
servation which it would be desirable to institute. 



On Teaching Perspective by Models. By Henry Twining. 

Mr. Twining exhibited models and demonstrated by figures drawn on glass the 
importance of having the perspective plane selected in a proper position to the seve- 
1849. 3 



34 REPORT — 1849. 

ral groups to be embraced in the picture, and the distance of that plane properly 
proportioned to the breadth of the picture. 



The President exhibited a Universal Sun-dial, made by Mr. Sharp of Dublin. It 
consists of a cylinder, set to the day of the month, and then elevated to the lati- 
tude. A thin plate of metal in the direction of its axis is then turned by a milled 
head below it till the shadow is a minimum, when a dial on the top shows the 
hours by one hand and the minutes by another. It appears that the time can be 
obtained by this to the precision of about three seconds. 



CHEMISTRY. 



Inquiries on some Modifications in the Colouring of Glass hy Metallic Oxides. 
By G. BoNTEMPs. 

In this communication some important practical points connected with the coloured 
ornamentation of glass and porcelain were brought forward. In the tirst place, it was 
shown that all the colours of the prismatic spectrum might be given to glass by the 
use of the oxide of iron in varying proportions and by the agency of different degrees 
of heat; the conclusion of the author being, that all the colours are produced in 
their natural disposition in proportion as you increase the temperature. Similar 
«phaenomena were observed with the oxide of manganese. Manganese is employed 
to give a pink or purple tint to glass, and also to neutralize the slight green given by 
iron and carbon to glass in its manufacture. If the glass coloured by manganese re- 
mains too long in the melting-pot or the annealing-kiln, the purple tmx, turns first to 
a light brownish-red, then to t/elloiv, and afterwards to green. White glass in which 
a small proportion of manganese has been used is liable to become light yellow by ex- 
posure to luminous power. This oxide is also in certain window-glass disposed to 
turn pink or purple under the action of the sun's rays. M. Bcntenips has found that 
similar changes take place in the annealing-oven. He has determined, by experiments 
made by him on polyzonal lenses for M. Fresnel, that light is the agent producing 
the change mentioned ; and the author expresses a doubt whether any change in the 
oxidation of the metal will explain the photogenic effect. A series of chromatic 
changes of a similar character were observed with the oxides of copper; the colours 
being in like manner regulated by the heat to- which the glass was exposed. It was 
found that silver, although with less intensity^, exhibited the same phsenomena; and 
gold, although usually employed for the purpose of imparting varieties of red, was 
found by varying degrees of heating at a high temperature and recasting several times, 
to give a great niany tints, varying from blue to pink, red, opake yellow and green. 
Charcoal in excess in a mixture of silica-alkaline glass gives a yellow colour, which 
is not so bright as the yellow from silver; and this yellow colour may be turned to 
a dark red by a second fire. The author is disposed to refer these chromatic changes 
to some modifications of the composing particles rather than to any chemical changes 
in the materials employed. 

On an Improvement in the Preparation of Photographic Paper, for the pwposes 
of Automatic Registration ; in which a long-continued action is necessary. 
By C. Brooke, F.F.S. 

The preparation of the paper described previously, may be thus briefly stated. 
The paper is washed over by a bru.-ih with a solution of 12 grs. of bromide of 
potassium, 8 grs. of iodide of potassium, and 4 grs. of isinglass in one fluid ounce of di- 
stilled water, and dried quickly. When about to be used, it is washed over by a brush 
with a solution of 50 grs. of nitrate of silver to 1 fluid ounce of water, and placed on 
the cylinder of the registering apparatus, on which it remains in action for twenty- 
four hours. When removed, the impression is developed by brushing over a warm 



TRANSACTIONS OF THE SECTTONS. 35 

solution of gallic acid, containing 20 grs. in the fluid ounce, to which a little strong 
acetic acid is added, and is then fixed with a solution of h)'posulphite of soda in 
the usual manner. The present improvement consists in rinsing the paper in water 
after the application of the solution of nitrate of silver, pressing out the superfluous 
moisture in folds of blotting-paper, and then adding a little more of the solution of 
nitrate of silver to the surface of the paper; this is most conveniently effected by pour- 
ing a small quantity on the paper, and then passing a glass rod or tube lightly over 
the paper, by which the solution is evenly distributed over the surface, and the con- 
tact of organic matter avoided. The increased sensibility and improved cleanliness 
of the paper consequent on this addition to the process, are presumed to depend on 
the removal by washing of the nitrate of potash formed by the mutual decomposition 
of the salts on the surface of the paper. 



Researches on the Theory of the principal Phenomena of Photography in the 
Daguerreotype Process. By A. Claudet. 

The various questions treated by M. Claudet were the following: — 

1. What is the action of light on the sensitive coating? 

2. How does the mercurial vapour produce the Daguerreotype image? 

3. Which are the particular rays of ligiit that impart to the chemical surface the 
affinity for mercury ? 

4. What is the cause of the difTerence in achromatic lenses between the visual and 
photogenic foci ? Why do they constantly vary ? 

5. What are the means of measuring the photogenic rays, and of finding the true 
focus at which they produce the image? 

Light produces two different effects on the Daguerreotype plate capable of giving 
an image. By one the surface is decomposed, and the silver is precipitated as a white 
powder; this action is very slow. By the other, the parts affected by light receive 
an affinity for the mercurial vapour, and this metal is deposited in white crystals. 
This action, which is the cause of the Daguerreotype image, is 3000 times more rapid 
than that producing the decomposition of the surface. After having examined the 
phaenomena of these two actions, M. Claudet considers that it is impossible to refer 
them to the same cause. The first is a chemical decomposition of the surface, and 
the second is a mere new property imparted to the surface to attract the vapour of 
mercury, which is given by some particular rays and withdrawn by some other rays. 
The most refrangible rays produce the affinity for mercury, and the least refrangible 
withdraw it. 

M. Claudet afterwards explained the principle of his photographometer, and 
several improvements he has lately made in that instrument, by which he can com- 
pare upon the same plate a series of intensities in a geometrical progression, varying 
from 1 to 512, and when employing two plates at the same moment, from 1 to 8192; 
and by another modification of the instrument — by shutting one-half of every hole 
through which the light has affected the plate, and submitting this half to radiation 
through red, orange or yellow glasses — he can study the modifications produced on 
these various intensities of effect, by these coloured or insulated radiations. The ex- 
periments to which M. Claudet refers would be too long to enumerate here, and 
we shall conclude by alluding to the most important point of this paper, which is the 
question of the difference between the visual and photogenic foci in achromatic 
lenses, and the constant variations they undergo by the influence of unknown causes, 
at all events, which he has not been able to ascertain. It is known that several years 
ago M. Claudet was the first to point out the difference between the two foci, and 
the necessity for the operator to place exactly the plate at the point where the pho- 
togenic focus is produced, in order to have a correct Daguerreotype image. But 
the new important fact lately observed by M. Claudet refers to the constant variation 
between the proportionate distance of these two foci. It appears that, according to 
some causes which M. Claudet has not been yet able to discover, the two foci for 
the same distance of an object are sometimes coinciding, and sometimes very far, 
one from the other; and what is most remarkable is, that the difference varies ac- 
cording to some properties of the lenses, in such a manner that when the two foci 
coincide in one case they may be very much separated in the other. 

3* 



36 REPORT — 1849. 

On the Black Colouring Matter of the Lungs. By Dr. De Vrij. 

This was a statement of an examination of a peculiar black substance wliich is often 
found in t!ie lungs of aged persons. It could not be detected in the lungs of in- 
fants; and its nature does not appear to have been yet determined, or the causes 
which produce it ascertained. 



On Ai-tificial Gems. By I\T. Ebelmen. 

This was a note accompanying some specimens of artificial gems prepared by M. 
Ebelmen under the influences of heat and pressure, as described in his communica- 
tions to the Academy of Silences of Paris. 

Dr. Percy rend a communication from M. Ebelmen, informing the Section that 
in addition to the specimens of crystallized gems recently furnished, he Iiad now ob- 
tained artificially oxide of titanium, niobic acid and tantalic acid by some modifica- 
tions of his process. 



On the Formation of Dolomite. By Professor Fohchhammer. 

Prof. Forchhamm^r communicated some observations upon dolomites. He stated! 
that the white chalk of Denmark is covered by a bed only a few feet thick, contain-] 
ing corals of the genera Cnrt/opht/Uia and Ocitlina, and a number of fossils different! 
from those of the white chalk; that this bed, which may be seen over a great part 
of Denmark always in the same position, the same fossiliferous character, and the 
same thickness, is enlarged in the hill of Faxoe to a thickness which cannot be much 
less than 150 feet. Here the Faxoe limestone is covered by a bed of dolomite, which 
again is covered by a thick bed of limestone, consisting almost entirely of fragments 
of Bryozoa, and belonging likewise to the chalk formation. The limestone of Faxoe 
contains about 1 per cent, of carbonate of magnesia, arising from the shells and corals, 
which always contain it in a small quantity, but which in some instances, as in the 
Ms and some Scrpults, amounts to 6 or 7 per cent. The bryozoan limestone which 
covers the dolomite contains not more than 1 per cent, of carbonate of magnesia, 
while the dolomite contains 16 or 17 per cent. 

The dolomite occurs generally in round globular masses, very similar to those of 
Humbledon Hill, and are evidently, like most of the globular masses of limestone, 
such as confetti di Tivoli and the peastone from Carlsbad, the produce of springs; an 
opinion which is still more confirmed by a number of large vertical tube-like cavities, 
which pass through the compact limestone, and are completely similar to those de- 
scribed by severaf English geologists as passing through the chalk, which liave been 
recognized as the natural pipes of springs, 'i'hus the Faxoe dolomite is the produce 
of springs; but then these springs have deposited stalagmitic limestone wherever 
they have passed through the crevices of the limestone rock, which, as a more or less 
thick coating, covers all the fossils. Now this produce of the springs contains only a 
very small quantity of magnesia, but, besides lime, a great quantity of oxide of iron. 
It appears thus that if no other reaction takes place than the escape of carbonic acid, 
the springs do not deposit carbonate of magnesia, but that the dolomite is formed 
where the carbonic acid springs come in contact with sea water. 

The author has made a great number of experiments on the decomposition which 
takes place when water containing carbonates dissolved by carbonic acid acts upon 
sea water, and found that always a more or less great quantity of carbonate of mag- 
nesia was precipitated with the carbonate of lime. When using water containing 
only carbonate of lime, the quantity of carbonate of magnesia thrown down at a boil- 
ing heat amounted to 12^ per cent., the rest being carbonate of lime. The results 
of this decomposition vary however very much, and according to conditions not yet 
well known. So nmch however may be stated, that the quantity of carbonate of 
magnesia precipitated increases with the increasing temperature. Water which, be- 
sides carbonate of lime, contains carbonate of soda, throws down a much larger quan- 
tity of carbonate of magnesia, amounting in one experiment to 27'93 per cent, of the 
precipitate. 



TRANSACTIONS OF THE SECTIONS. 37 

At last the author tried what kind of precipitate some of the most famous mineral 
springs of Germany would form, if they at the boiling-point acted upon sea water. 
Thus he obtained from the water of Sellers — 

Carbonate of lime 86'55 

Carbonate of magnesia 13'45 

10000 
From the water of Pyrmont — 

Carbonate of lime 84-38 

Carbonate of magnesia 3"12 

Protoxide of iron 1050 

10000 

The oxide of iron in the experiment was of course precipitated as peroxide of iron, 
and from that the carbonate was calculated. 

From the water of Wildungen — 

Carbonate of lime 9212 

Carbonate of magnesia 7'88 

10000 



On a New Method of ascertaining the Quantity of Organic Matter in Water. 

By Prof. FORCHHAMMER. 

The test which the author applies is hypermanganesiate of potash or soda, which 
he prepares in this way; he heats the hydrate of potash or soda with chlorate of pot- 
asii and peroxide of manganese, according to the method of VVohler. After heating, 
the salt is thrown into water, and so much diluted muriatic acid is added that it 
assumes a bluish-red colour, upon which carbonic acid gas is led through, until the 
colour has become bright red and the manganesiate of potash completely converted 
into hypermanganesiate. The liquid must be cleared, either by allowing it to deposit 
all the oxide of uianganese, or by filtering it through asbestos. This liquid may be 
kept for a very long time unaltered in a glass vessel with a glass stopper. The next 
process is to ascertain the strength of the test, which is done by taking any deter- 
mined measure of it, mixing it with water and a little alcohol, and then heating it. 
All the manganese is thrown down, and after being washed and exposed to a strong 
red heat, it is the compound oxide of manganese, 3Mn-f 40. 

This test is now applied in such a way, that, for instance, one pound of the water 
which is to be tried is mixed with a small quantity of the test and boiled; if the colour 
has disappeared, another quantity is added, and the liquor again boiled, until, in going 
on in that way, the red colour of the liquid does not disappear any longer. After that 
it is allowed to cool, and then the quantity of hypermanganesiate of potash, which has 
not been decomposed for want of organic matter in the water, is determined by com- 
paring its colour with distilled water, to which have been added very small deter- 
mined quantities of the test solution. If the quantity of the test which thus is added 
in excess is subtracted from the whole quantity which has been used, the real quan- 
tity of decomposed hypermanganesic acid is determined, and thus also the quantity 
of organic matter itself. This method is liable to one fault, viz. that the nature of 
the organic matter may be different, and accordingly require different quantities of 
the test liquor to be decomposed. But the organic matter which generally occurs 
in water is approaching almost always to humic acid, and thus the determination of 
the organic matter is practicable. As to that part of the organic matter in water 
which contains nitrogen, the author thinks that he has found out a method to de- 
termine it by itself; but not having yet finished his experiments on that point, he 
must leave it out of the question. 

Water taken from a greensand spring about twelve miles from Copenhagen, con- 
tained so little organic matter that 1 pound only required 6 measures of a test solu- 
tion, of which 100 measures contained the manganese of 0"526 of the double oxide 
of manganese, while water taken from a lake which communicates with a peat moss, 
required for 1 pound 74 measures of the same liquor. Prof. Forchhammer, con- 



38 REPORT — 1849. 

tinuing for a whole year every week this analysis of the water which is used to pro- 
vide Copenhagen, observed the following facts : — 

1. The quantity of organic matter is greatest in summer. 

2. It disappears, for the most part, as soon as the water freezes. 

3. Its quantity is diminished by rain. 

4. Its quantity is diminished if the water has to run a long way in open channels. 



On the Compounds of the Halogens with Phosphorus. 
By J. H. Gladstone, Ph.D. 

It is well known that chlorine, bromine, and iodine will combine directly with 
phosphorus, yielding compounds containing three atoms of the halogen. Cyanogen 
does not so combine. If a larger amount of the halogen be employed, compounds 
are formed containing five atoms. Ail these substances are neither basic nor acid j 
they are resolved l)y water into the hydracids of the halogens, and phosphorous or 
phosphoric acid. If phosphorus be distilled with chloride, bromide, or iodide of mer- 
cur}', the ter-compound results. There exists a ter-fluoride (Davy). The ter-cya- 
nide is doubtful. 

The penta-compounds of the halogens with phosphorus may easily be reduced to 
the ter-compounds. The addition of fresh phosphorus will effect this in each instance. 
Phosphuretted hydrogen has already been observed to reduce the pentachloride; it 
has the same effect upon the pentabromide. Hydrogen alone has no reducing power 
upon either of these compounds. Heat alone however will effect the reduction of 
the pentabromide J if a current of dry air be passed over it at 212° F., so as to re- 
move the free bromine, pure terbromide is obtained. The higher compound of iodine 
and phosphorus may be similarly decomposed, but not the pentachloride. 

The force of affinity for phosphorus is in the order — chlorine, bromine, iodine. The 
ter-compounds are not directly acted upon by oxygen or sulphur, but suffer double 
decomposition by water or hydrosiilphuric acid. The comparative feebleness with 
which the two additional atoms of the penta-compounds are combined, is also evident 
from the action of certain non-metallic elements; thus, iodine reduces the pentabro- 
mide of phosphorus. The moderated action of water upon the pentachloride forms an 
oxychloride of phosphorus (Wurtz), and there exists an oxybromide of phosphorus, 
PBrgOo, exactly analogous. No compound, similar to the sulphochloride of phos- 
phorus of Serullas, is formed by the action of hydrosulphuric acid on the pentabro- 
mide, but a liquid, the analysis of which appears to suggest the composition SPBrj 
-f PS3. No such compounds exist in the iodine series. 

The increased stability, which the substitution of two atoms of oxygen, or sulphur, 
for two atoms of the halogen, imparts to the remaining three atoms, is manifest from 
— 1, the non-action of hydrosulphuric acid; 2nd, the fact that metals, even potas- 
sium, are not attacked by them ; 3rd, the non-action of phosphorus. 

Hydrochloric acid produces no partial double decomposition with the pentabromide 
or pentiodide. Nor does any halogen combine directly with the ter-compound of 
another with phosphorus. If bromine and iodine be presented simultaneously to 
the terchloride, pentabromide of phosphorus is formed. A colourless crystalline body 
exists, belonging to the bromine series, never obtained in quantity, possibly isomeric 
with the oxybromide. 

Sulphur appears to combine directly with pentachloride of phosphorus when they 
are fused together; a crystalline body, and a straw-coloured liquid result. The 
analysis of these compounds is attended with peculiar difficulty, nor had the author 
sufficient time to investigate all the anomalies of their decomposition. The straw- 
coloured liquid however would appear to be P CI5 S4. The provisional name of Sul- 
phurets of the Pentachloride of Phosphorus is given. 



On a continued spontaneous Evolution of Gas at the Village of Charlemont, 
Staffordshire. By Samuel Howard. 

In a field by the side of a lane, near the village of Charlemont in Staflfbrdshire, 
certain patches of ground had been noticed, which, without any apparent cause, were 
destitute of vegetation. They excited little attention, as they were supposed to be 



TRANSACTIONS OP THE SECTIONS. 39 

what are commonly called fairy rings, and it was not till the summer of 1846 that 
their true character was discovered. 

The person who first paid particular attention to the cause of these barren spots, 
was the tenant of a neighbouring cottage (at which there is a cold bath, noted in the 
vicinity for its sanative properties). From certain circumstances he was led to be- 
lieve that something permeated the earth in those spots; and having dug a hole, he 
inserted a gas-pipe, and on applying a light to the mouth of the pipe, he found to his 
great surprise that a large flame issued from it. It was not long before he conceived 
the idea of applying it to domestic purposes, and in pursuing his experiments he found 
that it was not necessary to convey it from the place where it was first discovered, 
at a distance of about 150 yards from his house, as on driving a pipe some inches 
into the ground under the floor of the cottage, he procured a continuous flow of gas. 

There are at the present time seven burners in the cottage, which enable the owners 
to dispense with fire and candles. The next cottage is also supplied with two. It ap- 
pears to make no difference to the supply of gas if allowed to burn for weeks toge- 
ther, and the flame is always of the same colour. In windy weather the flame is 
generally unsteady ; when there is a blast of wind outside the flames of gas rise seve- 
ral inches, but as each blast dies away they return to their original size. The escape 
of gas is larger in wet weather than in dry ; but whether the gas is produced near the 
surface or otherwise has not yet been satisfactorily ascertained. The place where it 
issues from the earth is quite a mile from any coal-pit, and is outside the eastern edge 
of the Staffordshire coal basin. 

The gas, as analysed by myself from a portion of it (procured for me by Mr. S. 
Lloyd, jun. of Wednesbury, about three miles from the place), was composed prin- 
cipally of light carburetted hydrogen. In 1000 volumes of the gas, as it rises, I pro- 
cured 996 vols, of light carburetted hydrogen, .3 of carbonic acid, and 1 of aqueous 
vapour and nitrogen. Its specific gravity is 0'56126. Its composition is somewhat 
different from the gas known as marsh gas, and from that which collects in the old 
workings of mines, as it contains less carbonic acid, and less nitrogen ; the propor- 
tion in marsh gas of the fornieJ' being —^ and of the latter ^^ to ^V. whereas in this 
gas the proportions are only Vo'oo ^"tl toW- 

It burns with a pale bluish-white flame, emitting considerable light and heat. 
Mixed with atmospheric air or oxygen, it explodes with considerable violence on con- 
tact with flame, or with the electric spark. As it issues from the pipe it has a moist 
or slightly musty smell, as of sticks partially decomposed, but after keeping for some 
time in stopped glass jars this is lost, and it becomes perfectly inodorous. When 
inhaled in large quantities it produces the same effects as hydrogen gas, but it does 
not appear to exert any evil influence on the health of the inhabitants of the cottage, 
when diluted with a large portion of atmospheric air. 



On Copper containing Phosphorus, with Details of Experiments on the Corrosive 
Action of Sea-water on some Varieties of Copper, By John Percy, M.D., 
F.R.S. 

Upon analysing a specimen of copper, to which when in a state of fusion some 
phosphorus had been added, it was found that it contained a considerable quantity 
of phosphorus, and also a large portion of iron derived from an iron rod employed in 
stirring the mixture at each addition of the phosphorus. The copper employed 
was of the " best selected " — it appeared to be harder than copper treated with 
arsenic. The details of the analysis of 1 1 676 grains were given, the result of which 
was — 

Phosphorus 093 

Iron 1-99 

A second analysis gave — 

Copper 9572 

Iron 2-41 

Phosphorus 2-41 

100-54 
It has long been stated that a very small quantity of phosphorus renders copper ex- 
tremely hard, and adapts it for cutting instruments, but such an alloy as that formed 



40 REPORT — 1849. 

by Dr. Percy lias not previously been formed. It is a remarkable fact, that the pre- 
sence of so large a quantity of phosphorus anil iron should so little affect the tenacity 
and malleability of the copper. The effect also of phosphorus in causing soundness 
in the casting of copper is interesting, and may be of practical importance. Some 
experiments were next described, made by Capt. James of Portsmouth, bearing on 
the oeconomic value of the alloy of phosphorus and copper. By the experiments made 
by Capt. James on the corrosive action of sea- water, it would appear that this com- 
pound was much less affected tlian most other specimens of copper tried. The re- 
sults derived from exposing measured pieces of copper to the action of sea-water for 
nine months were as follows : — 

grains. 

Electrotype copper, loss per square inch 1-4 

Selected copper I'l 

Copper containing phosphorus "0 

Copper from the " Frolic" 1'12 

Dockyard copper, No. 1 1'66 

Ditto No. 2 3-00 

Ditto No. 3 2-48 

Ditto No. 4 233 

Muntz's metal 0-95 

The results appear to be of sufficient importance to excite attention to the fact, and 
to elicit further inquiry, especially when it is remembered how important and ceco- 
nomi'; a desideratum it is to the Admiralty to diminish or prevent the corrosive effect 
of sea- water upon copper. 

On the Decomposition and partial Solution of Minerals, Rocks, 8<c. by pure 
Water and Water charged with Carbonic Acid. By Prof. W. B. Rogers and 
Prof. R. E. RoGKRS, of the University of Virginia. 

In opening this communication. Prof. W. B. Rogers adverted to its important bear- 
ings upon the chemistry of geology, and the theories of the formation of soils and of 
the nutrition of plants. He referred to the comparatively isolated experiments of 
Struve, Forchhammer and others, as being of too restricted a scope to furnish a basis 
for reasoning generally on the disintegration of rocks, the formation of chalcedonic, 
zeolitic and other minerals by solution, and the conveyance of inorganic materials 
into the structure of plants. It therefore becomes a question of importance, whether 
water pure, or charged with carbonic acid, possesses that general decomposing and 
dissolving power which some chemists have vaguely and without sufficient evidence 
ascribed to it, or whether this action applies only to the few materials hitherto tried, 
and which all contain an alkali. 

The experiments of the Professors Rogers were of two kinds ; first, by an extempora- 
neous method with the tache ; and secondly, hy prolonged digestion at the ordinary tem- 
[jcrature. In the former, a small quantity of the mineral in very fine powder is di- 
gested for a few moments on a small filter of purified paper, and a single clear drop 
of the liquid received on a platinum slip is dried and examined by appropriate tests 
before and after ignition. In the second process a quantity of the finely-powdered 
mineral is placed with the liquid in a green glass bottle and agitated from time to 
time for a prescribed period. The liquid separated by filtration is evaporated to dry- 
ness in a platinum capsule. The residuum is then critically examined, and, if in suf- 
ficient amount, is submitted to quantitative analysis. 

In both processes two parallel experiments were made, the one with pure aerated 
water, the other with water charged to saturation at 60° with carbonic acid. In the 
second process, correction was made for the alkali, lime, &c. dissolved from the con- 
taining glass, by making separate experiments in similar vessels without the mineral 
powders. 

1. When the substance is very minutely powdered before mingling it with the 
liquid, even the first drops that pass the filter will commonly give a tache containing 
some of the alkali or alkaline earth that has been dissolved. In this way proof of 
the action of the carbonated water may generally be obtained in a few minutes after 
adding it to the powder. In the case of pure water the action is feebler and requires 



TRANSACTIONS OF THE SECTIONS. 41 

a longer time, but with nearly all the substances enumerated it is distinct, and with 
some of them quite intense. 

2. By an independent series of experiments to determine the effects of lieat, which 
were made upon the taches of potassa and soda and their carbonates, and upon those 
of carbonate of lime and magnesia, as well as upon considerable quantities of these 
substances successively exposed in a crucible to the heat of the table blowpipe, it 
was found that the order of volatility was as follows : — potassa, soda, magnesia, lime. 
The tache of potassa disappeared almost at once, that of soda lingered some time, 
that of magnesia wasted more slowly, while that of lime remained with little altera- 
tion for a long time. 

Before heat was applied the tache oHhe alkalies or their carbonates would of course 
be strongly alkaline. That of the carbonate of magnesia also presented a decided 
and sometimes strong reaction with the test-paper, while that of carbonate of lime 
gave a merely appreciable effect. But on raising the tache to a red heat, the car- 
bonate of lime, by escape of carbonic acid, would acquire intense alkalinity, the re- 
action of the magnesia tache would be but little altered, and that of the alkaline 
taches would be almost or entirely destroyed. 

As examples of this distinctive testing and of the mode of proceeding in these tache 
experiments. Professors Rogers gave some details, extracted from the large mass of 
unpublished results, and called attention particularly to the contrasting phaenomena 
in the cases of Leucite, Olivine and Epidotej the first characterized by potassa, the 
second by magnesia, and the last by lime. 

Thus in the case of Leucite, the water tache and carbonic acid water tache were 
both alkaline, the latter very strongly so. But even gentle ignition for a few seconds, 
or strong ignition for a moment, was found entirely to dissipate the alkali. 

In the case of Olivine, the water tache was decidedly alkaline, and that from car- 
bonic acid water greatly more so. Ignition produced for the first second or two but 
little change, but its continuance caused a gradual diminution of the alkaline re- 
action, which at the end of ten seconds was reduced to about one-twelfth of what it 
was at first. 

With Epidote the tache presented an extremely feeble reaction before heating. 
Ignited for a moment, the alkalinity was intense, and after ten seconds of ignition but 
little abatement of the alkaline reaction was discerned. 

3. Referring to the second method of experimenting used by the Professors Rogers, 
viz. that o( prolonged digestion in water oi- carbonic acid water. Profs. Rogers exhibited 
results obtained with hornblende, epidote, chlorite, mesotype, &c., showing that the 
amount of solid matter dissolved by the carbonated water in many of these cases is 
quite sufficient for a qualitative analysis, even when the digestion has only been con- 
tinued for forty-eight hours. When further prolonged, they have procured from the 
Hquid a quantity of lime, magnesia, oxide of iron, alumina, silica and alkali, the dis- 
solved ingredients of these minerals severally amounting sometimes to nearly one 
per cent, of the whole mass. 

4. In connection with theprecedinginvestigntions, the Professors Rogers were led to 
an examination of the comparative solubility of carbonate of lime and carbonate of mag- 
nesia in carbonated water. In the standard chemical and geological works the car- 
bonate of lime is stated to be the more soluble, and on this supposed fact is founded 
a common theory of the origin of the large quantities of carbonate of magnesia in 
the niagnesian limestones. It was conceived that in a mixed limestone containing 
both the carbonates, the relative amount of carbonate of magnesia would be augmented 
through the more rapid removal of the carbonate of lime by the percolating waters, 
and that thus the mass would approach mpre and more to the composition of a do- 
lomite. 

The experiments of the Professors Rogers demonstrate that in water impregnated 
with carbonic acid, carbonate of magnesia is much more soluble than carbonate of lime. 
Thus, by allowing the slightly-carbonated water to filter through a mass of magnesian 
limestone in fine powder, and collecting the clear liquid, analysis detected a much 
larger proportion of carbonate of magnesia in the solution, in comparison with the 
carbonate of lime, than corresponded with the amount of these substances relatively 
in the powdered rock. Again, by agitating briskly a quantity of the powder with the 
carbonated water in a glass vessel and then separating the liquid by filtration, it was 



42 REPORT — 1849. 

found that a larger relative amount of the carbonate of magnesia had been taken up 

by the solvent than of carbonate of lime. 

From these experiments the Professors Rogers infer that the infiltering rain-water, 
with its slight charge of carbonic acid, in passing through or between strata of mag- 
nesian limestone, will remove the carbonate of magnesia more rapidly than the car- 
bonate of lime, and that thus the rock will gradually become relatively less magnesian, 
instead of being made to approach the condition of a dolomite, as is commonly main- 
tained. 

Professors Rogers called attention to the fact, that the stalactites in caverns of mag- 
nesian limestone contain only minute quantities of carbonate of magnesia. An exa- 
mination of those in Weyer's cave in Virginia had proved that while the milky white 
opake stalactites contain a small but measurable amount, the sparry and more trans- 
parent kinds are almost destitute of a trace of this ingredient. It is evident that in 
such cases the carbonate of magnesia is carried off by the liquid below, and that such 
is the case seems to be confirmed by the fact of the large amount of carbonate of 
magnesia found in the springs in the immediate neighbourhood of the cave just 
named. 

5. A fact of much interest noticed in these experiments is the comparative readi- 
ness with which the magnesian and calcareo-magnesian silicates yield to the decom- 
posing and dissolving action of carbonated water and even simple water. This ex- 
plains the rapid decomposition of most rocks composed of hornblende, epidote, &c., 
without calling in the agency of an alkali, and it enables us to trace the simple pro- 
cess by which plants are furnished with the lime and magnesia they require from soils 
containing these silicates, without our having recourse to any mysterious decom- 
posing power of the roots of the growing vegetable. 

6. In their tache ex[)eriments, the Professors Rogers ascertained that the powder of 
anthracite, bituminous coal and lignite all yielded a discernible amount of alkali to 
the carbonated water, while the ashes of these materials, similarly treated, gave no 
alkaline trace on the test-paper. This they think is at once explained by the high 
temperature at which the ash is formed, which by experiments already noticed is 
quite sufficient to dissipate any portion of alkali or carbonate originally present in 
the material. 

On the Allotrop'ic Condition of Phosphorus. By Prof. Schroetteh of Vienna. 

This communication being already before the world in the 'Annuaire de Chimie' of 
Millon and Reiset, it is unnecessary to do more than briefly state the facts, which Prof, 
Schroetter illustrated by experiment. When phosphorus is exposed to light or heat, 
it is found that a peculiar change of colour takes place, and that although it under- 
goes no chemical change, a very remarkable physical difference is found to have 
ensued. The ordinary yellow phosphorus is highly inflammable. The allotropic red 
phosphorus was not ignited by friction, nor by those agents which acted energetically 
upon the common variety. 

On the combined Use of the Basic Acetates of Lead and Sulphurous Acid in the 
Colonial Manufacture and the Refining of Sugar, By Dr. Scoffekn. 

Dr. Scoffern, after a few preliminary remarks on the anomalies which beset the 
colonial manufacture of sugar, stated the actual amount of pure v.'hite and crystalliz- 
able sugar existing in the sugar-cane juice to be from 17 to 23 per cent., and the 
amount of juice contained in the cane to be about 90 per cent. Of this amount 
only 60 per cent, on an average is extracted, and of this quantity only one-third 
part of its sugar is obtained, in a dark impure condition, instead of white and pure, 
as it might be extracted. The operation at present generally followed in the 
colonial production of sugar involved the use of lime, an agent which, although 
beneficial in separating certain impurities and decomposing others, effects both these 
agencies at the expense of two-thirds of the original sugar. 

Various plans had been followed to avoid the use of lime; alumina in its hydrated 
condition had been employed, but with inconsiderable success. As a purifying agent 
the basic acetate of lead was known to be most potent, but could not be generally 
employed, owing to the existence of no efficient means of separating any excess of 



TRANSACTIONS OP THE SECTIONS. 43 

that agent which might remain. Dr, Scoffern effects this separation by means of 
sulphurous acid forced by mechanical means into the sugar solutions. The process 
had been used for more than twelve months in one of the large British refineries, 
and a lump of sugar prepared by means of the operation was exhibited. 
The advantages presented by this operation were thus summed up: — • 

1. As applied to cane-juice, and other natural juices containing sugar, it enables 
the whole of the latter to be extracted, instead of one-third, as is now the case, and 
in the condition of perfect whiteness, if desired, without the employment of animal 
charcoal. Owing to the complete separation of impurities, the juice throws up no 
scum when boiled, and therefore involves no labour of skimming. Finally, the pro- 
cess of curing is effected in less than one-third of the present time; and the sugar 
being in all cases pure and dry, no loss in weight occurs during the voyage home. 

2. As applied to the refinery operation, it enables the manufacturer to work upon 
staples of such impurity that he could not use them on the old process. It yields 
from these staples a produce equal in quality to the best refined sugars produced 
heretofore, in larger quantity and in less time. It banishes the operation of scum 
pressing, the employment of blood and lime. Finally, its cost is even less than that 
of the present refinery process. 

On the Composition of the Ash of Armaria maritima, grown in different Locali- 
ties, and Remarks on the Geographical Distribution of that Plant, and the 
Presence of Fluorine in Plants. By Dr. A. Vcelcker. 

The presence of iodine in plants growing near the sea, and the absence of that ele- 
ment in the same species of plants growing in inland situations, have been noticed 
some years ago by Dr. Dickie of Aberdeen, who likewise found that in the former 
soda was more abundant, and potash prevailed in the latter. The author found Dr. 
Dickie's observations confirmed by his own, and no qualitative analyses of the sea- 
piuk {Armeria maritima) having been made, he analysed the ashes of specimens from 
three different localities, and obtained the following results (the carbonic acid and 
sand found by actual experiment havingbeen deducted, the result calculated for 100): — 

Potash 

Soda 

Chloride of potassium 

Chloride of sodium 

Lime 

Magnesia 10-98 

Oxide of iron 

Alumina 

Phosphoric acid 

Sulphuric acid 

Silicic acid 

Iodine Traces. 

Fluorine Traces 

10000 10000 10000 

No. T. was grown near the sea-shore, and washed by the sea-spray at high water. 
No. II. was grown on an elevated granitic rock opposite the former locality. 
No. HI. in Mr. Lawson's nursery near Edinburgh. 
Several observations are suggested by the inspection of the above results: — 

1. The proportion of alkaline chlorides, as well as that of silica, in all three ashes 
is considerable. 

2. The quantity of soda is more abundant in the ash of specimens grown near the 
sea-shore, whilst potash prevails in those grown on the rock. 

3. Soda is entirely replaced in the ash oi Armeria maritima grown in the nursery. 

4. The larger quantity of phosphoric acid and potash in the ash of specimens grown 
in the nursery, viewed in connection with the greater vigour and the somewhat changed 
natural character of the cultivated plant, appears to exercise a great influence on the 
natural character of Armaria maritima. 



No.I. 


No. II. 


No. Ill 


8-86 


8-85 


1381 


4-47 








8-22 


26-65 


24-03 


18-44 




13-50 


14-44 


912 


10-98 


11-95 


4-28 


7-92 


6-83 


6-62 


1-97 






5-77 


11-75 


21-07 


7-92 


8 68 


7-33 


14-58 


10-84 


11-12 


Traces. 






Traces. 


Traces. 


Traces, 



44 REPORT — 1849. 

5. Traces of fluorine, hitherto found in only few plants, were distinctly detected 
in ail three ashes; iodine only in specimens grown near the seashore. 

The author then adverted to the geographical distribution of the sea-pink in Ger- 
many, and represented the above analyses as well-calculated to throw light on the 
causes which contribute to chain some plants to a particular well-defined geognostic 
formation, by showing that a soil deficient in soluble silica and alkaline chlorides, of 
which the sea-pink requires a considerable quantity, is unable to sustain the life of that 
plant. According to Schleiden, the sea-pink, found everywhere upon the arid sand- 
dunes of the northern coasts of England, is universally distributed over the sandy plains 
of northern Germany. In middle and southern Germany it is found only in a few 
places, and these arc distinguished by their arid, sandy character j and curiously enough, 
we find that the Armeria marltima disdains the richest soils in its range of geographical 
distribution. Thus we find in northern Germany the granite, clay-slate and gypsum 
of the Hartz mountains, and rhe porphyry and muschelkalk of Thuringia, setting a 
limit to the Armeria viaritima, and we meet with it only until we arrive at the Keuper 
sand plains in the neighbourhood of Nuremberg. In southern Germany it is found 
extending through the Palatinate, but neither on the Suabian Alps nor the whole 
alpine region is it found, and it appears at last again on the sandy plains of northera 
Italy. The fact that the sea-pink is not found in every sandy soil in Germany, sug- 
gests the idea that those inland localities where it occurs have been perhaps the 
bottoms of ancient lakes, and that the soil in these places will contain much salt. In 
England and Scotland the sea-pink is found universally on the sea-coasts, but with a 
few exceptions, we do not meet with it in inland situations. A remarkable excep- 
tion of this general rule of its geographical distribution in England is offered by the 
appearance o? Armeria maritima on the summits of several mountains of the Scottish 
highlands. How does it happen that it does not occur in the lowlands and localities 
much nearer the sea? The author regretted to have been unable to procure the 
material for an analysis, which might probably have assisted him in throwing light 
on the subject; but expressed the hope to be enabled to examine the ash of specimens 
from the Highlands in the course of the current year, specimens having been pro- 
mised to him by Prof. Balfour of Edinburgh. In the meantime he communicated an 
analysis of dried specimens which he obtained from the herbarium of the Botanical 
Society of Edinburgh, but for obvious reasons he does not put much confidence in 
the accuracy of these analytical results. The analysis however indicated likewise a 
considerable amount of alkaline chlorides in the ash oi Armeria maritima from the 
Scottish Highlands. Armeria maritima is not the only marine plant which presents 
this peculiarity; several others, for instance Plantago maritima, are found under 
similar circumstances. Having had no opportunity of examining the localities in 
the Highlands where these plants occur, the author declined to enter on the theory 
of this peculiar occurrence, further than to ascribe an important share to the salt, 
which in the spray of the sea is often carried to considerable heights into the air, and 
which, it is not unreasonable to suppose, has been deposited again by the rain, par- 
ticularly in those places which are exposed to regular sea-winds, in such quantities 
as to answer to the requirements of the sea-pink and other marine plants. He con- 
sequently recommended naturalists interested in the subject to ascertain whether 
those localities in Highland mountains, where these marine plants occur, are exposed 
to frequent sea-winds or not, and to pay general attention to the meteorological 
conditions of these places. 

In conclusion, the author stated that distinct traces of fluorine had been detected 
in the three different ashes oi Armeria maritima, and likewise in the ash of Cochharia 
officinalis. In the ashes of Dutch Kanaster tobacco no fluorine could be detected, but 
as tobacco leaves are soaked in water when prepared for Kanaster, it may be that the 
trace of fluoride of calcium, if present, has been dissolved out by the water, fluoride 
of calcium having been shown to be joluble in water, to some extent, by Dr. G. Wil- 
son of Edinburgh, 

The simultaneous presence of silica in the ashes of most plants renders the detec- 
tion of fluorine rather difficult, because the methods hitherto known for tracing the 
presence of fluorine in siliceous mixtures are impracticable, in all cases in which we 
have to deal with traces of fluorine and large quantities of silica. By following a 
plan recommended by Dr. G. Wilson, the author was enabled to prove distinctly the 



TRANSACTIONS OF THE SECTIONS. 45 

presence of fluorine iu the above plants, and he h confident that other chemists, fol- 
lowing the same direction, will find it in other plants in which it is likely to occur. 



On a Form of Galvanic Battery. By W. H. Walenn. 

The present form of battery has been the result of an attempt to combine the prin- 
ciples of the batteries now in use, and to avoid some of their present inconveniences. 

Its metallic elements are, — highly carbonized cast iron as a negative plate, and 
zinc, prepared in a way to be described afterwards, as a positive plate. 

The solution is formed by dissolving some of the cast-iron plates, intended to form 
the negative plates, in one part by measure of oil of vitriol to eight of water, and 
when there is no free acid in the liquor, adding one-eighth of oil of vitriol. 

In the last battery made (one of 6-inch square plates) the zinc plates were prepared 
by dipping them in dilute sulphuric acid, to cleanse thera, washing them well in water, 
then dipping them in a solution of acetate of lead, and drying the laminal deposit 
thus obtained over a charcoal fire; mercury, with a little dilute sulphuric acid being 
then rubbed over the plate, unites with the lead, and this amalgam with the zinc; the 
excess of mercury is then driven off by second heating over a charcoal fire, and the 
plate is prepared. 

In the form which I have employed, the plates are fixed in a skeleton frame of 
wood, one-sixteenth of an inch apart, alternately iron and zinc, with glass plates be- 
tween every metallically connected pair ; the frame with its plates is then placed 
in a trough (of glass in this instance) containing the solution as made above. 

The quantity of electricity passing has been tested with two separate galvano- 
meters, and found to be half that evolved from a Maynocth battery, with plates of 
the same area, in a given time : this experiment has been repeatedly tried when the 
battery has been just put to work, and when it has been at work with a galvanometer 
in the circuit a whole day. 

One galvanometer was not very delicate, either in the mounting of the needle or 
the thinness and number of convolutions of its wire, being designed rather for the 
measure of large quantities of electricity, than to test the existence of a small 
amount. 

The other was extremely delicate in the mounting of the needle, and therefore 
could be depended on for its registrations ; the current from a single cell battery, 
having a positive plate of 16 square inches active surface, and two negative plates of 
the same active surface each, passing through a wire one-sixteenth of an inch dia- 
meter, and 1 J inch from the needle, immediately beneath it, deflected the needle 
more than 30°. 

In estimating the quantity of electricity evolved from different batteries, Barlow's 
theorem was used; viz. that the quantity of electricity passing through a given gal- 
vanometer is directly proportional to the tangent of the angle of deflection. 

It was observed, in testing the above single cell battery, that in every instance 
when the battery contact was broken, a small bright spark was visible in daylight. 

It has been remarked that the longer the same solution has been used in an active 
battery, the longer will the addition of a given quantity of sulphuric acid keep the 
flowing current of electricity constant; also that the battery is much more energetic 
if it be left out of action, for a time equal to that during which it has been in ac- 
tion, immersed in water; it is also necessary that a considerable volume of solution 
should surround the plates. 

This battery is clearly a combination of the principles of the batteries known as 
Daniell's, Suiee's, Van Melsen's, Chevalier Bunsen's, Sturgeon's, the Maynooth, 
Schonbein's Inactive and Active Wrought Iron Batteries, and Robert's. 

The following advantages peculiar to these.batteines, follow from what has been 
said above : — 

1 . Great strength of current both in intensity and quantity. 

2. Constancy of action. 

3. Protosulphate of iron in pure crystals, and pure carbon in fine powder as a sale- 
able residuum, also a sulphate of zinc. 

4. Very great reduction in the current expense of batteries as well as their first 
cost, porous tubes not being used. 



46 REPORT — 1849. 

5. The plates may be placed at the sixteenth of an inch, and even less, apart : an 
enormous acting surface may thus be obtained in a very small space, and an additional 
strength of galvanic current, owing to the nearness of the plates. 

6. 'J'here is no danger of the boiling of the solution. 

7. The plates once arranged in a suitable framing would not require to be disturbed 
for a very considerable period. 

Since the above was written, further experiments have been made, in order to 
simplify the method of preparing the zinc plates, and the following is the method 
which appears the best : 

After the plates are cleaned with emery, immersion in dilute sulphuric acid, and 
then in water, they are dipped into a mixture of about equal parts by measure of 
saturated solutions of chloride of mercury (corrosive sublimate) and acetate of lead ; 
they are then rubbed with a cloth and washed, and are ready for use. 

The superiority of this method of preparing the plates consists in the fact, that 
local action is entirely prevented, and they only require one preparation until they 
are quite dissolved ; they are not so liable to break as common amalgamated plates 
are, and are therefore able to be used as long as any metal remains. 

They are also more highly positive than common amalgamated zinc plates. 



On Motions exhibited hy Metals under the Influence of Magnetic and Dia- 
magnetic Forces. By W. Sykes Ward. 

In the course of a series of experiments in relation to diamagnetism, I observed 
that the nature of the action upon many metals varied with the intensity of the mag- 
netic force; and I found that such effects vvere in accordance with the observations 
of Prof Plucker, " that the diamagnetic force increases more rapidly than the mag- 
netic in relation to the power of the exciting magnet." I took considerable care in 
procuring specimens of pure silver, cop[)er, lead, tin and zinc, and found that these 
assumed the magnetic or diamagnetic state according to the power of the magnet 
employed. I found a magnet of very moderate size and power sufficient if the polar 
pieces vvere brought near to each other, and the metals, the subject of experiment, 
were in small discs and delicately suspended. 

My attention being particularly directed to the phaenomena which Dr. Faraday 
terms revulsion, I observed that the direction of the revulsive motions changed when 
the magnetic or diamagnetic state of the metal was changed. 

When the polar pieces were adjusted within one quarter of an inch apart, and the 
disc of metal so suspended that one-half was without, and the other half between the 
polar pieces, another series of phasnomena presented themselves. On developing 
the magnetic force, the disc moves as a pendulum, with a tendency to pass outwards 
from between the polar pieces; on breaking contact, the disc moved in the reverse 
direction, tending to pass within the polar pieces. Such motions are remarkable, in 
that the direction of them is alike in all metals. Such motions appear to result 
from electrical currents rather than from magnetic or diamagnetic forces ; for on sub- 
stituting for the disc of metal a flat spiral of insulated wire, they were not produced ; 
but on using a similar spiral, but of which the ends of wire were in good contact, 
the like phaenomena were observed as with a disc. 



On a Theory of Induced Electric Currents, suggested by Diamagnetic Ph<E- 
nomena. By W. Sykes Ward. 

The phaenomena mentioned in the foregoing paper involve many points which 
cannot be easily accounted for according to the received theories of magnetism. 
Ampere's theory may account for magnetic or diamagnetic phaenomena taken sepa- 
rately, but not easily for the changes of condition which take place in the same metal, 
still less for the changes in the direction of the revulsive motions, particularly those 
which follow the sluggish condition of the metal under the influence of that amount 
of force by which the ma;i;neti5m or diamagnetism are nearly balanced. 

It also appears that the induced or secondary electric current may be accounted 
for on the hypothesis that the current in the primary conductor effects a molecular 



TRANSACTIONS OP THE SECTIONS. 47 

disturbance in the parallel or secondary conductor (such disturbance being in the 
nature of a magnetic affection), and that such disturbance correlatively induces the se- 
condary current, both when it is produced and when it ceases. This hypothesis is 
also in accordance with the fact that this induced current is only transient, and also 
appears the best explanation why the induced is not of equal duration with the 
inducing current. 

On the comparative Cost of working various Voltaic Arrangements. 
By W. Sykes Ward. 

The author stated that a series of calculations, founded on tables produced to the 
Chemical Section at Swansea, showed the efficient power of three generally used 
forms of battery, known as Smee's, Daniell's and Grove's, would be equal when 100 
pairs of Smee's, 55 pairs of Daniell's, or 34 pairs of Grove's were used ; and that the 
expense of working such batteries, as regards a standard of 60 grains of zinc in each 
cell per hour, would be about 6e?., T\d, and M. respectively. 



On the Presence of Nitrogen in Mineral Waters. By W. West, F.R.S. 

In this paper the author corrects the statement of Dr. Granville, in his ' Spas of 
England,' that the continental chemists do not find nitrogen gas in their analyses 
of mineral waters ; whence the Doctor infers either some extraordinary difference be- 
tween the spas of England and of the Continent, or some error in the experiments of 
British chemists. Mr. West shewed, by quotations from many statements, prin- 
cipally of German chemists, that they at least, in many instances, state the propor- 
tion of nitrogen found by them, and that in those cases where this is omitted, the 
absence of nitrogen is not to be inferred, but only that they made no examination of 
the gaseous contents, beyond ascertaining the quantity of carbonic acid present. 



On the Presence of Fluorine in the Waters of the Firth of Forth, the Firth of 
Clyde, and the German Ocean. By George Wilson, M.D., F.R.S. E. 

In 1846, the author announced to the Royal Society of Edinburgh the discovery 
of fluorine as a new element of sea water. He was led to search for it, after ob- 
serving that fluoride of calcium possesses a certain small but marked solubility in 
water, which explains its occurrence in springs and rivers, and necessitates its occa- 
sional, if not constant presence in the sea. The only specimens of sea water he had 
examined before this summer were taken from the Firth of Forth at Joppa, about 
three miles from Edinburgh. He obtained the mother-liquor, or bittern, from the 
pans of a salt-work there, and precipitated it by nitrate of baryta. The precipitate, 
after being washed and dried, was warmed with oil of vitriol in a lead basin, covered 
with waxed glass having designs on it. The latter were etched in two hours as 
deeply as they could have been by fluor-spar treated in the same way, the lines being 
filled up with the white silica separated from the glass. 

The author has recently examined in the same way bittern from the salt-works at 
Saltcoats in the Firth of Clyde, but the indications of fluorine were much less di- 
stinct than in the waters on the east coast. On procuring, however, from the same 
place, the hard crust which collects at the bottom and sides of the boilers used in 
the evaporation of sea water, he found no difRculty in detecting fluorine in the deposit. 
This crust, or deposit, consists in greater part of sulphate of lime and of carbonate of 
lime and of magnesia; but it contains also much chloride of sodium, and the other 
soluble salts of sea water entangled in its substance. When sulphuric acid, ac- 
cordingly, is poured on it, it gives off much hydrochloric and carbonic, as well 
as some hydrofluoric acid, and the latter is thus swept away before it has time to 
corrode the glass deeply. The author preferred, nevertheless, to use the crust 
exactly as he got it, that the proof of the presence of fluorine might not be impaired 
in validity by the possibility of that substance being introduced by the water or re- 
agents which must have been employed, had the chlorides and carbonates been sepa- 
rated from the crust by a preliminary process. The crust, accordingly, after being 
dried and powdered, was placed along with oil of vitriol in a lead basin covered by 



48 REPORT— 1849. 

a waxed square of plate-glass, with letters traced through the wax. A single charge 
of the crust and acid corroded the glass only slightly; but by replenishing^ the basin 
with successive quantities of these materials, whilst the same plate of engraved glass 
was used as the cover, he found no difBculty in etching the glass deeply. The author 
is indebted to his friend Mr. S. Macadam for this simple but effective way of in- 
creasing the corrosion of the glass, which seems worth the adoption of chemists in 
all cases where fluorine is sought for. Four charges of material have been sufficient, 
■with all the si)ecimens of sea-water deposit he has examined, to mark the glass 
strongly. It was kept wet on the up|)er side, and exposed undisturbed to the action 
of each charge during twelve hours. Operating in this way, he has found fluorine 
readily in the boiler-deposit from the waters of the Filths of Forth and Clyde. It 
is a less easy matter to subject the waters of the open sea to the requisite concen- 
tration before examination. It occurred to the author, however, that the incrusta- 
tions v/hich are periodically removed from the boilers of the ocean steamers would 
serve to determine the question whether fluorine is a general constituent of the sea. 
He made application, accordingly, at Glasgow and Leith for the deposits in question. 
It appears, however, that the deep-sea steamers which leave the former have their 
boilers cleaned out at other ports, so that he has as yet been unsuccessful in pro- 
curing crusts froni the west coast of Scotland. He has obtained at Leith the crust 
from the boiler of a steamer called the ' St. Kiaran*,* which trades between thai port 
and Montrose; so that the greater part of the water consumed as steam by its en- 
gines is derived from the German Ocean, although a portion is necessarily obtained 
from the Firth of Forth. The crust from the boilers of this vessel was treated in the 
way described, and at once yielded hydrofluoric acid. A single charge, indeed, of 
the materials marked the glass distinctly, and four charges deeply. We may there- 
fore infer that fluorine is present in the waters of the German Ocean, for different 
portions of the deposit yielded it readily, and marked glass as deeply as the deposit 
from the water of the Firth of Forth did, which could not have been the case if the 
whole crust had not contained fluorine pretty equally diffused through it. 

It will be an interesting matter to have similar examinations made of the boiler 
deposits from the Transatlantic, and other ocean steamers which make long voyages; 
nor will it be difficult, where the crust is thick, to select portions from the interior 
of the deposit, which may be regarded as best representing the contents of the sea 
at a considerable distance from land. From what is known of the comparative uni- 
formity in composition of sea water, it may safely be inferred that if fluorine be 
present in the waters of the Firths of Forth and Clyde and in the German Ocean, it 
will be found universally present in the sea. In one of the interesting communica- 
tions which Prof. Forchhammer has laid before the British Association, he has shown 
that the more marked ingredients of sea water vary little over wide areas. One of 
the ingredients selected by this gentleman to mark the uniformity in composition of 
the sea, is lime, and as it is exceedingly probable that the fluorine in sea water exists 
in the state of fluoride of calcium, his observations may be referred to as in harmony 
with the inference that the element in question is generally diffused through the sea. 
Other proofs, however, are not wanting. Mr. Middleton, before 1846, came to the 
conclusion that fluorine must be present in sea water, since it occurred, as he had 
ascertained, in the shells of marine moUusca. Silliman, jun., without a knowledge 
of Middleton's views, drew the same inference, from its mvariable presence in the 
calcareous corals brought to America by the United States' expedition from the Ant- 
arctic seas. The author has found fluorine abundantly present in the teeth of the 
walrus, which points to its existence in the Arctic Ocean ; and it seems so invariably 
to associate itself with phosphate of lime, that it may be expected to occur in the 
bones of all animals marine and terrestrial. 

The author has found fluorine likewise in kelp from the Shetlands, but much less 
distinctly than he anticipated. Glass plates were only corroded so far as to show 
marks when breathed upon. Prof Voelcker also was kind enough, at the author's 
request, to search for fluorine, when analysing the ashes of specimens of the sea pink 

* In the account of this paper contained in the Athena;um report of the meeting of the 
British Association for 1849, the name of the vessel was inadvertently called the ' Isabella 
Napier ' instead of the ' St. Kiaran.' They both traded between Leith and the northern 
parts of Scotland. 



1 



TRANSACTIONS OP THE SECTIONS. 49 

{Statice Armeria), which had grown close to the sea-shore and contained iodine, and 
found fluorine in the plant. 

When all those facts are considered, it is not too much, the author thinks, to urge 
that fluorine should now take its place among the acknowledged constituents of sea 
water. He has entered at length into the consideration of the natural distribution 
of this element, and into other details connected with it, in a paper in the Transac- 
tions of the Royal Society of Edinburgh, vol. xvi. part 7, and in a communication 
made to the Association at its Southampton meeting. The author further notices, 
incidentally, that the only ascertained plant, so far as he knows, in which fluorine had 
previously been detected, is barley, in which Will found it. In 1846 the author 
detected this element in American potashes, and it now appears to be one of the 
constituents of the kelp sea-weeds, although the observations which were made on 
commercial kelp are liable to the objection, that the fluorine detected might be de- 
rived from sea water which had dried upon the kelp weed before it was burned. 

The Statice A rmeria may certainly be added to the list of plants containing fluorine, 
and so may the Cochlearia Anglica, in specimens of which obtained from the Bass 
Rock, and analysed in Dr. Wilson's laboratory, Dr. Voelcker has also detected this 
element. 

Specimens of etched glass were shown to the Section in illustration of this com- 
munication. 

P.S. The specimens of etched glass sent, are seen to most advantage if placed on 
a sheet of paper and held in direct sun-light, or any other bright flame, so that the 
shadows of the grooves which form the letters may fall upon the paper. 



Analytical Investigations of Cast Iron. By F. C. Wrightson. 

This series of analyses showed the influences of the hot blast in producing the so- 
called " cold short iron," by occasioning an increased reduction of phosphoric acid, 
and the consequent increase of phosphorus in the " hot-blast " iron. The respective 
per-centages were : — 

I. II. III. IV. V. VI. VII. 

Cold blast 0-47 041 0-31 020 0-21 0-03 036 

Hot blast 0-51 0-55 050 071 054 0-07 040 

The irons differed also considerably as to the state in which the carbon was con- 
tained, the hard white iron resembling impure steel, containing nearly all its carbon 
in a state of chemical combination, whilst the carbon contained in the gray and 
mottled varieties of iron was principally contained only as a mechanical mixture. 
The presence of sodium and potassium in all the specimens examined was also no- 
ticed for the first time, and it was thought probable that these might materially alFect 
the qualities of the metal. 



GEOLOGY AND PHYSICAL GEOGRAPHY. 

Notes on the Geology of the Channel Islands. 
By Robert A. C. Austen, F.R.S. 

The object of the present short communication is not to give a detailed account of 
the mineralogical character of the various crystalline rocks which form so large a por- 
tion of this group, nor to lay down their topographical extent. The publication of facts 
of this class does not form any part of the objects of the British Association, and all 
that I would now attempt is a few general results, for the purpose of discussion, on 
one or two points in geological investigation, which these islands help to elucidate. 

The mineralogical constitution of Guernsey in particular, as is well known, was 
investigated by Macculloch, himself a native of that island. 

From the position of this group with reference to the coast of France, it is obvious 
that comparisons must be instituted rather with the formations of the Cotentin, than 
with anything on the English side of the channel. One great difficulty which every 

184.9. 4 



50 REPORT 1849. 

one must have experienced in attempting to investigate the relations of the mineral 
masses of the Cotentin, arises from the want of natural sections, owing partly to the 
manner in which its surface is covered by heath and wood, and partly to superficial 
accumulations ; a difficulty, which, though it exists to considerable extent in tiie 
larger islands of Guernsey and Jersey, is obviated by the great extent of coast-line 
they present. 

The sedimentary rocks of Guernsey and Jersey are of inconsiderable extent ; a 
small patch of clay-slate occurs in Rocquaine Bay, on the west of Guernsey, and 
larger areas are occupied by it in the north and north-east parts of Jersey : in the 
latter they are occasionally siliceous, and pass into subordinate beds of rounded con- 
glomerate. The whole of this group has been variously moved about, but its general 
slope as a mass is to east. These beds are evidently a part of the palaeozoic series of 
the Cotentin, and closely resemble that portion of it which, consisting of alternations 
of compact sandstones and argillaceous shales, are well seen on the north and south 
of Valognes. The calcareous bands of the French series are altogether wanting, nor 
did I see any of those peculiar steaschist beds, with nodules of quartz, which in the 
neighbourhood of Cherboin-g underlie the middle part of the group. 

Organic remains, if not entirely wanting, must be exceedingly scarce in these beds, 
in which respect they agree with that part of the French series to which I have com- 
pared them. 

No trace of any one of the secondary series of formations is to be found over these 
islands ; the surface of the slate rocks has been much denuded, and the like process J 
may have removed whatever newer strata may have at some time existed there ; but/ 
fi'om certain characters which the new red sandstone and the cretaceous beds put on in 
their extension into the west of France, it is more probable that beds of that period 
never were deposited here. 

The geological interest which attaches to these islands consists in the relative ages of 
the crystalline rocks, which form so large a portion of their masses. A circumstance 
which cannot fail to strike any observer is the very great changes of mineral character 
which these masses put on, and within very narrow limits : there is, however, a three- 
fold division, which is apparent enough : — 

1. A flat-bedded crystalline group, such as that which occurs over the southern 
half of Guernsey. 

2. A granitic group, which includes a series of gray, red, and black granites. 

3. A sienitic series, comprising a vast variety of combinations, in which, however, 
hornblende prevails. 

The first of these groups, as it is seen in Guernsey, is of great thickness, and though 
no topographical limits can well he drawn, it maybe said to occupy all south of a line 
from Castle Cornet to Vason Bay ; it is in some places a true granite, at others gneiss, 
at others a true micaceous schist. It agrees with the next group as to the constituent 
minerals into which it graduates downwards. 

The true granites are to be seen over the northern part of Guernsey, nowhere better 
than in the quarries of St. Sampson's parish. These latter, as a mass, underlie the 
first group, and their more massive external character, as well as more imiform cry- 
stalline texture, may be merely the results of cooling under rather different condi- 
tions ; and tlie whole may be an intrusive plutonic mass of the same period. On the 
other hand, portions of the upper group irresistibly suggest the notion that at some 
time they nuist have existed as sedimentary strata. 

In the island of Jersey the true granites occupy the southern portion, and it is only 
here that we see their relation to the slate series already noticed. As the slates ap- 
proach the granite, they become hard and splintery. At this junction enormous veins 
or branches extend from the granitic mass, as well as the most delicate threads ; at 
places the slate rocks seem reduced to fragments, among which the fluid granite has 
poured itself, the angular edges being sharp and uninjured. 

The granite of this island puts on a character more closely resembling stratification " 
than is usually seen; so nmch so, that in many places, as for instance in the steep 
walls of rock beneath the citadel of St. Heliers, it might be, excusably mistaken for a 
mass of highly inclined sedimentary beds. These divisioni.have no general angle of 
dip, but are inclined most unequally ; they may be planes of cooling which were once 
horizontal, and have acquired their present position by subsequent disturbance. The 
extreme smoothness of their surfaces is very remarkable. 



TRANSACTIONS OF THE SECTIONS. 51 

In the red granites I observed one set of planes running nearly north and south, 
with a dip to the west and a cross set east and north, and which had a dip north. 

Hornblende is not absent in the second group of crystalline rocks, as an occasional 
constituent; and in these cases, as in St. Sampson's parish, it makes its appearance 
by gradual increase, and as it were by passage from one rock to another. 

The third group is quite distinct : the different appearances which it assumes, from 
the preponderance of one or other of its constituents, would cause it to be described 
mineralogically under a great variety of names. I noticed, however, a single dyke in 
the island of Jersey which in one place was an earthy hornblende (wacke), then com- 
pact greenstone trap, hornblende with distinct crystals of felspar; lastly, hornblende, 
with large plates of mica. 

The intrusion of the hornblendic series is of subsequent date to that of the granitic 
rocks : as to the period in the geological scale at which this took place, it would be 
hazardous to conjecture; they have broken up and been projected amongst the gra- 
nites, in the same manner as we have seen that the granites affected the slate rocks. 
A vast lapse of time must have been required for the cooling down of the fluid gra- 
nitic masses ; yet it is evident that the whole of that structure of divisional planes was 
complete before the intrusion of the sienitic rocks; an illustration of this represented 
the dyke in every instance following one of these sets of planes. But for nume- 
rous other sections, where the granite is seen caught up in the greenstone in great 
angular masses, it might be supposed that the two rocks were arranged in parallel 
beds; instances of the subsequent date of the hornblende series is perhaps best seen 
in Jersey, but good examples are to be found in Guernsey. 

At several places in this same island is to be seen a deposit of fine sedimentary 
matter, conforming to the irregular surface of rock on which it rests. These accumu- 
lations have for a few years past been worked for the purposes of brick-making, so that 
good sections can be obtained. Their position is on the high table-lands of the south 
part of the island, so that at the time of their deposition the whole must have been 
submerged ; but besides this, the beds themselves would indicate a great depth of 
water. No fossils that I could ascertain have ever been met with. In one or two of 
the lower portions of this deposit, and where the sands were rather coarser, I detected 
fine sharp angular fragments of chalk flints ; and guided by many considerations which 
it would be needless to mention here, but which will readily suggest themselves to 
those acquainted with the geology of the south-west parts of France, it seemed to me 
that these beds might be outlying patches of the deep sea eocene period. 

The geological phenomena of these islands next in date are referable to sub-aerial 
conditions — the deep disintegration of the crystalline rocks, and the accumulation of 
the materials so produced. The thickness of these accumulations indicate a long lapse 
of time ; they cover not only all portions of the larger islands, but are found capping 
the smaller groups of rocks which surround them : they come down to the present 
sea-level ; they evidently, by their position, belong to a period when the whole of 
those islands had a much greater amount of elevation than at present. 

The old peat-beds and forest-trees of Catel parish belong to this period of sub-aerial 
conditions, as do also the submerged forests which run out from these islands at so 
many places, Vason Bay, Grand Cobo. 

The elevation of the whole of this group at this line was probably very consider- 
able. 

Up to a height of no great amount above the sea, the surface is covered by an ac- 
cumulation of sharp sand, with occasional lines of shingle ; chalk flints enter largely 
into the composition of this. In the parish of St. Sampson it will be seen resting on 
the surface of the granite, as in many of the quarries ; but it occurs equally on the sub- 
aerial beds ; the thickness of these accumulations is very trifling, and can only indi- 
cate a depression beneath the present level of very transient duration. In the Island 
of Jersey such lines of inland cliff as that which extends from Gorey southwards, at 
the base of which lie the ancient marine beds, covered along the sea-bord with blown 
sands, would indicate a rather lengthened period of stability before the last change of 
level. 

Such is the series of physical change which this group of islands appears to have 
undergone ; its geological history is simple compared with many other districts, but 
for the apparent fact that it should have preserved tracts as dry land through so many 
surrounding changes, and probably since the post-eocene period. 

4* 



52 REPORT — 1849. 

On some Neio Species of Tcstacea from the Hampshire Tertiary Beds. 
By E. Charlesworth, F.G.S. 

Mr. Charlesworth stated that the British Natural History Society had employed 
collectors to obtain fossils from the eocene strata of Hampshire, and that amongst the 
20,000 specimens already obtained were seven new to this country: — 1. A Cytherea 
with the external form of Isocardia. ?.. A Purpura'', with a single prominent plait 
on the columella. 3. A Cancellar'ia. 4. A shell allied to Cerithium. 5. Murex 
triptrroklc'n (Deih.). 6. Fusus e.vcisiis (Lam.). 7. A variety o( Murex defossus (Sow.). 
Mr. Charlesworth remarked on the importance of investigating particular deposits, 
especially where there was any danger of good localities being destroyed, as in the 
case of the Bridlington crag. 

On the Geography and Geology of the Peninsula of Mount Sinai and the ad- 
jacent Countries. By John Hogg, M.A., F.R.S., F.L.S., Hon. Sec. of the 
Royal Geograph. Soc. S;c. 

In communicating a brief account of the geography and geology of the peninsula 
of Mount Sinai, and of the countries immediately adjoining to it, the author in the 
first place took a hasty survey of the chief natural features of the peninsula, beginning 
at Suez, and following the Siuaic coast of the Gulf of Suez as far as its south point at 
Has Mohammed, and thence up the Sinaic coast of the Gulf of Akaba to its north 
extremit}'. 

Secondly. From the Kalah el Akaba down the Arabian shores of that gulf, he de- 
scribed that region, the little isles of Tiran, Senafer, and others which lie to the S. of 
Ras Furtak, and then the districts near Ain Uneh and Moweilih, on that coast of 
Arabia. 

Thirdly. Passing from Moweilih up the Gulf of Akaba, lie gave some views of it, 
of the VVadi el .Araba, and of the neighbouring mountains, as far north as the ruins 
of Petra. 

Fourthly. On the rocks of Petra the author offered a few remarks, also on Gehel 
Harun, and the mountains of the Nabathaean chain, those to the N.W. of Wadi el 
Jerafah, the great desert of El Tyh, the range El Egmeh, the Sinaic group, and Gebel 
el Tyh and G. Thughar. 

Fifthly. Starting again from Suez, he shortly noticed that east region of Egypt 
which is contiguous to the Gulf of Suez, nearly as far south as the supposed site of 
Myos Hormus. 

And, sixthly. In conclusion, he observed upon the general features, the heights of 
the mountains, the geological formations, the minerals and ores of the peninsula of 
Mount Sinai. 

The plain map that accompanied this paper was carefully reduced from a much larger 
one (which was also exhibited and coloured geologically), drawn and compiled by the 
author from the maps of Professors Lepsius, Russegger and Robinson (the last ex- 
ecuted by Kieppert at Berlin), and from the charts of the survey of the Red Sea, by 
Messrs. Moresby and Wellsted, under the authority of the East India government. 
For the purpose of keeping the map as clear as possible, and not crowded with names, 
those of the chief places are alone inserted. The Arabic, the classical and scriptural 
appellations are added. It was recently engraven by Mr. VV. Hughes for the Royal 
Society of Literature, in order to illustrate the author's previous memoiron MountSinai, 
now publishing in the forthcoming part of their Transactions*. 

Mr. J. Hogg also exhibited a copy of the same, which he coloured geologically, 
principally after Russegger's maps of Egypt and the Sinaic peninsula, very lately 
executed at Vienna; but the latter he corrected in some places according to the de- 
scriptions of Burckhardt and other travellers who had visited them in person. 

An imaginary section, likewise geologically tinted, was described ; it comprehended 
the peninsula from Gebel Jaraf on the north to Ras Mohammed on the south. This 
the author himself enlarged, eight times, from a portion of a more extensive section, 
neatly engraved with the altitudes derived from Russegger's work, by Herr Augustus 
Petermann. 

* See Second Series, vol. iii. pait 2. pp. 183, 236. 



TRANSACTIONS OF THE SECTIONS. 53 

Two other geological sections, which the author sketched and coloured, were also 
explained; the first was a representation of the 'Granite Peaks of the high Sinaic 
mountains,' enlarged after Russegger; and the second was entitled, ' Section of the 
Wadi el Araba, from the Gulf of Akaba to the Dead Sea, showing what portion is now 
lower than the level of the Red Sea.' He likewise stated that the stoppage of the 
River Jordan through that Great Wadi (supposed to have once flowed through it) 
might have been effected by a volcanic agency, traces of which exist about the Dead 
Sea, and near the head of the same gulf. 

It is impossible in the limits of the present abstract to follow the author through 
his several divisions, wherein he carefully recorded the chief facts relating to the 
rocks, mountains, and plains, and the nature of the respective formations. But some 
of the geological characters, and the different formations of these countries, as far as 
they are at present known, are the following . — 

I. Diluvium, alluvium, sand, marine formation, coral rocks, &c. 
II. Tertiary sandstone, upper Nubian sandstone, and oldest diluvium. 

III. Tertiary limestone and marl. 

IV. Limestone of the cretaceous series. 

V. Older sandstone, Nubian sandstone, and its marl (lower cretaceous series). 

VI. Unstratified or crystalline rocks ; granite, sienite, porphyry, diorite, greenstone, 
felspar, gneiss, chlorite, hornblende, mica and clay-slates, &c. 
VII. Volcanic rocks ; basalt, and basaltic lava. 

The distribution of these formations over these regions of Arabia and Egypt is 
briefly thus : — 

A large tract of beds comprised in I. occurs around the head of the Gulf of Suez 
and to the N.W., where exist the salt marshes, Szabegha. Then due N. a strip of 
tertiary sandstone and oldest diluvial beds, II. ; next, a narrow piece of tertiary lime- 
stone and marls. III. ; again a large extent of II., interrupted by a narrow belt of III. 
running N. and S., which stretches out N.E. nearly to 34° E. long. From thence 
the immense desert of El Tyh with its many plateaux of different elevations, bounded 
by Gebel el Rahah on the W., the Gebel el Tyh range on the S.W., S., and S.E., 
nearly to the line of 29° N. lat. consists of IV., limestone of the cretaceous fovmation, 
but covered in places by large tracts of sand, gravel, and flints. The western coast 
of the peninsula is 1., about as far as Ras Soddur from the head of the Gulf of Suez 
on the W. ; but to the E., including more than half the range of El Rahah, III. pre- 
vails. Between that Ras (cape) and Wadi el Amarah, there intervenes an outlying 
piece of IV. From the last valley (Wadi) to about El Hamam Faroun, III. again 
comes in, which continues a little to the E. of Howara. From Wadi Gharandel to the 
N.of WadiNaszb and the well of Morkha, except along the sea-shore and the plain W. 
of the latter spot, which are of I., bounded on E. by Gebel Watah, and from thence 
to W. Naszb in a S.W. direction, IV. extends. From that mountain to Sarbut el 
Chadem inclusive, and from Morkha on the coast plain to the head of El Kaa, below 
Mount Serbal on the W., the sandstone (secondary), V., and its marls occupy that 
district. Gebel Araba range, near the sea, is of limestone, IV. The long gravelly 
and sandy plain of £1 Kaa, which stretches out to the S. extremity of the peninsula 
is I., and more or less covei'ed with pebbles and detritus of the primitive i-ocks, VI. 
Along the coast there follows a small chain, including the remarkable G. Narkus of 
v., then succeeds G. Hemam, nearly as far as Tur Bay, composed of IV. Two 
patches of III. occur N. and S. of Tur; but that small town, the only one in the 
peninsula, stands on a raised coral bank and sand, I. South of Ras Sebil there is a 
little tract of III. ; and this reappears at Ras Mohammed; N.W. and N.E. of which 
low promontory some older sandstone, V., intervenes between it and the granitic roots 
of the Gebel El Turfa. East of Sherm, which is of V., volcanic rocks, VII., are seen, 
and crater-like appearances, fhence north-eastwards, V., where an intermediate 
strip of IV. is found at Wadi Nubk. Along the Sinaic coast of the Gulf of Akaba 
up to Noweibia from Wadi Orta inclusive, VI. prevails ; a little of V. occurring N.W. 
at Dahab, and in the lower part of W. Sal. 

The unstratified or crystalline rocks, VI., range from the S.E. of Sarbut el Chadem, 
bounded by the S.W., S., and S.E. sides of the elevated sand plain of V., called 
Debbet el Ramleh, and from Wadi Roniman, and the N. end of W. Firan, where it 
joins W. Mukatteh, along the eastern edge of El Kaa, to the S. termination of the 
El Turfa chain. Then N.E. of Wadi Sal, and N. of it to the northern branch of 



54 REPORT — 1849. 

El Tyh V. continues. Along the Sinaic shores of the sea of Akaba, from Noweibia, 
near which place is IV., the same extends northwards; somewhat to the west and 
north of this coast line, rocks of VI. and V, alternate, and occasionally with IV. ex- 
hibit many remarkable displacements ; W. of the granitic Isle of Kureiyeh are black 
basaltic cliffs, VII., along the beach ; then N. some breccia or conglomerate is noticed ; 
and afterwards granite rocks succeed. 

Ascending the Wadi el Araba, the mountains on the E. are of VI., chiefly porphyry 
with granite in places, to about 30° N. lat. ; near which occurs the watershed, at about 
an elevation of 500 feet above the sea in that Wadi, the inclined bed of which, from 
the gulf to that point, is formed of sand and gravel and debris. Sandstone, V., and some 
chalky limestone, IV., are met with on the W. side of the Great Wadi Araba. Those 
formations are elevated to about the level of the desert El Tyh, and in spots some- 
what higher. Fi'om about the line 80° N. lat. V. extends northwards be3'ond Gebel 
Hanm and the ruins of Petra, both inclusive, — except an intermediate strip in Wadis 
Gharundcl and Dalegheh running nearly W. and E., which is IV., and all along the 
E. side of this region, a lofty chain, attaining an altitude of perhaps 3600 feet above 
the sea, which the author termed the ' Nabathasan chain,' and proceeds a great di- 
stance north — consists of IV. On the other, the western side of the valley of the 
Araba, and opposite to Gebel Harun (Mount Hor), the abrupt Gebel Makrah and the 
peak of Gebel Araif el Naka, or the ' She Camel's Crest,' are likewise of the IV. 
formation. South of these begins "the great and terrible wilderness" of El Tyh, 
or ' the Wandering,' which has been already noticed. 

On the east of the Nabathaean chain, as also of the gi-anitic range of Mount Seir 
south of the line 30° N. lat., for a vast distance in the eastern desert, and to the S., 
the limestones of IV. extend. The mountains from Kalah el Akaba, the ' Castle of 
Akaba,' along the Arabian coast, are granitic, VI. At the promontory Ras Furtak is 
a low tract of IV. corresponding with that in the N. side of the opposite isle of Tiran, 
and with that in Wadi Nubk on the Sinaic shore. The coast then, south of the gra- 
nite mount Gebel Makna, in many places is of I., but between those and the granitic 
range behind Ain Uneh and Moweilih, the tertiary sandstone II. is, according to 
Russegger, again developed. Further inland, the sandstones, V., of the lower creta- 
ceous series prevail. 

Again, on the co.ist of Egypt, S. of Suez, Gebel Ataka, which is of the limestone 
IV., divides a tract on the N. and S. of tertiary limestone. III. ; the plain El Baidea 
being of I. S. of this a very considerable district of the secondary limestone IV. 
follows. On the heights above Wadi Zafraneh on the N., a strip of granite, VI., takes 
place, wherein exist traces of old copper mines. Near the coast S. of lias Zafraneh, 
some beds of tertiary limestone and marl, III., and some conglomerate rock, are 
found. In the Eastern Desert, a little S. of 28° 30' N. lat. and about 32" 30' E. 
long., there occurs some of the sandstone, V., of the lower cretaceous series, and called 
by Russegger ' sandstone of Nubia,' The mountains rising between that portion of 
the desert and the coast are for a great distance southwards primitive or granitic, VI. ; 
of these Gebel Garib or Agrib is the loftiest; its summit being elevated to about 
6000 feet above the sea level. Both N. and S. of it are observable remains of 
copper mines. 

The fossils of these tertiary and secondary formations have not as yet been suffi- 
ciently examined. Capt. Newbold states that he found among the many fossils of the 
limestone, IV., Ostrece, Echini, Madripora, and Pectines; and Herr Russegger ob- 
serves, that in the compact chalk rock of the same series, IV., at Ras Hamam in the 
Gulf of Suez, he observed remains of monocotyledonous plants ; and in the same for- 
mation, from the Gebel el Tyh, that is to say, compact chalk with flints, were numerous 
fossils. Mr. John Hogg however conceived it probable that some of the limestone 
formation, which Russegger assigns solely to the cretaceous series, in the vast district 
to the N. and E. of Gebel el Tyh, will, on further examination, prove to be of an 
older limestone. So he thought that certain of the sandstones of V. may, after future 
discovei'ies, be more correctly I'eferred to rocks anterior to the secondary, pei'haps to 
the Palaeozoic, epoch ; indeed in tlie older or secondary sandstone, V., Capt. Newbold 
could find no fossils. And with regard to the ages of the primitive or unstratified 
rocks, VI., of the Sinaic group, the same traveller, who examined them recently with 
care, says that the greenstone is the latest, and next in order the porphyry and gra- 
nite, and that the hypogene schists or slates are the oldest. 



TRANSACTIONS OF THE SECTIONS. 55 

Few minerals and ores occur in the Sinaic peninsula; of these iron and copper are 
the most abundant ; indeed, in hieroglyphics, Professor Lepsius remarks, that the whole 
country was called Mafkat, i. e. " the copper land." Neither lead nor silver has been 
detected, but near Mersa Dahab, which means the ' gold port,' some assert that gold 
dust is present, for the teeth of the Ibex ai"e sometimes seen surrounded with it. This 
probably may be only auriferous pyrites. Hematite, antimony, rock-crystal, cinna- 
bar, nitre, rock-salt, a yellow clay named tafal, crystallized sulphate of lime, sulphur, 
gypsum, pebbles of agate and jasper, occur. Thermal springs rise at Gebel Hamam 
and in El Wadi near Tur ; the former having a temperature of .55° R., and the latter 
91° Fahr. The porphyries and granites of the high Sinaic group vary extremely in 
colours, and some are of great beauty ; the latter resembling those near Assouan. 

According to Russegger, the highest peaks of that group, in fact of the entire 
peninsula, rise to 9300 English feet above the sea. A peculiarity in the lower mountain 
ranges is this : — generally an ascending valley (Wadi) leads up to the summit, which 
constitutes a plain, and then another Wadi slopes down to the level of the neigh- 
bouring district. Such is even the present general form of the long Wadi el Araba. 

The minerals and ores in Eastern Egypt are, the author believes, only iron, copper, 
and much naphtha or petroleum found at Gebel el Zeit, 'Mount of Oil;' and in that 
part of Arabia which comes within this notice, little or nothing is known of its mineral 
products. The soil however in several localities is much more fertile, and more 
abounding in water, than that either in Eastern Egypt or in the Sinaic peninsula. 

Mr. J. Hogg illustrated his observations with some beautiful lithographed views of 
Suez, of the mountains in the peninsula, of the head of the Gulf of Akaba, and the 
site of Petra, by Mr. David Roberts and the late Lieut. Wellsted. 



On the Relations between the New Red Sandstone, the Coal-measures, and the 
Silurian Rocks of the South Staffordshire Coal-field. By J. Beete Jukes, 
M.A., F.G.S. 

The author commenced by remarks on the interesting question of what rocks lay 
below the new red sandstone of the Midland Counties, and after giving a concise sketch 
of the structure of that district, directed attention to the particular instance of the 
South Staffordshire coal-field. He stated that a point of great practical importance was 
the nature of the boundary faults of the midland coal-fields, whether they were true 
faults, or only old cliffs of coal-measures with the new red sandstone abutting against 
them. Having been engaged in the government geological survey of South Stafford- 
shire, he wished to point out what results had been already arrived at. He showed 
that each of the three formations entering into the structure of the district (namely, 
the new red, the coal-measures, and the Silurian) were unconformable to the other; 
that this unconformability was rarely locally appreciable, the difl^erence in the dip or 
strike being slight, but was shown by each of the superior formations resting on dif- 
ferent parts of the inferior at different places. The nature of this unconformability 
was exhibited in the catting of the railway near Dudley, where beds of coal-measure 
sandstone abutted against a clitf of Silurian shale 20 or 30 feet high, both formations 
being nearly horizontal. He then briefly described the boundaries of the southern 
portion of the South Staffordshire coal-field, showing that on the east the new red sand- 
Btone was brought dovi-n against the coal-measures by a true downcast fault ; that the 
coal-measures were worked for some distance beneath the new red sandstone, but 
that they appeared to be suddenly thinning out in that direction near West Bromwich, 
andthata little east of the present workings the Silurian shale had been driven into, on a 
level with the thick coal; that Silurian shale had likewise been metwith nearthe surface 
south of Oldbury, and that it was therefore probable that there was a space on the east 
side of the present coal-field aboutSandwell and Smethwick, where the new red sand- 
stone rested directly on Silurian shale without the intervention of any coal-measures, 
but that this space was not of any very great extent, from true coal-measures having 
been reached not far from the Stonehouse near Harborue, and near Aldridge east of 
Walsall. He then traced the western boundary from Wolverhampton to Stourbridge, 
which he showed to be probably a true " downcast fault to the west," more or less 
complicated by minor faults and branches which spread from it into the coal-field. 
Along the southern edge of the field from Stourbridge, south of Halesowen to Lappal 
and the neighbourhood of Harborne, he described the boundary to be formed simply by 



56 REPORT — 1849. 

the superposition of the new red sandstone on the coal-measures, the beds of the latter 
dipping gently to the south, and the former resting on them with apparent conforma- 
bilily. He believed that here would be found the true upper beds of the coal- 
measures, and the lowest beds of the red sandstone, as deposited in that district, but 
doubted tlie existence of any beds of passage from one into the other. 

As a practical conclusion, he stated that while there was every hope that profitable 
coal-beds lay beneath the larger part of the new red sandstone plain of the Midland 
Counties and Cheshire, it would not be advisable rashly to commence a search for them, 
nor without competent direction and advice ; that this advice and direction might 
eventually be hoped for from the Geological Survey of Great Britain under Sir H. De 
la Beche. He likewise added, that if he were now asked to fix a limit of depth at which 
the coal was probably to be attained beneath the new red sandstone, he should say Jive 
or six hundred yards was the least depth the speculator would probably have to sink 
for it. 

On Traces of a Fossil Reptile (Sauropus primsevus) found in the Old Red Sand- 
stone. By Isaac Lea of Philadelphia. {Communicated hy Dr. Buckland.) 

The object of this communication is to announce to the Society that I have discovered 
the footprints in bas-relief of a reptilian quadruped lower in the series than has yet 
been observed. On the 5th of April last, in the examination of the strata in the gorge 
of the Sharp Mountain, near Pottsville, Pennsylvania, where the Schuylkill breaks 
through it, a large mass of remarkably fine old red sandstone attracted my attention. 
Upon it I was astonished to find six distinct impressions of footmarks in a double row 
of tracks, each mark being duplicated by the hind-foot falling into the impression 
of the fore-foot, but rather more advanced. The strata here are tilted a little over 
the vertical, and the surface of rock exposed was about 12 feet by 6 feet, the whole 
of which surface was covered with ripple-marks and the pits of rain-drops beautifully 
displayed in the very fine texture of the deep red sandstone. 

The six double impressions distinctly show, in the two parallel rows formed by the 
left feet on the one side and the right feet on the other, that the animal had five toes 
on the fore-feet, three of which toes were apparently armed with unguinal appendages. 
The length of the double impression is 4-^ inches ; the breadth 4 inches ; the distance 
apart in the length of the step of the animal 13 inches; across, from outside to out- 
side, 8 inches. The mark of the dragging of the tail is distinct, and occasionally 
slightly obliterates a small part of the impressions of the footmarks. The ripple- 
marks are 7 to 8 inches apart, and very distinct, as well as the pits of the rain-drops. 

The footmarks assimilate remarkably to those of the recent Alligator Mississippi- 
ensis, and are certainly somewhat analogous to the Cheirotherium. 

The geological position of this reptilian quadruped is of great interest, from the 
fact that no such animal remains have heretofore been discovered so low in the series. 
Those described by Dr. King, in the great western coal-field, are only 800 feet below 
the surface of the coal formation (No. 13 of Prof. Rogers, the State Geologist). The 
position of the Pottsville footmarks is about 8500 feet below the upper part of the coal 
formation there, which is about 6750 feet, according to Prof. Rogers, and they are in 
the red shale (liis No. 11); the intermediate siliceous conglomerate (No. 12) being 
stated by him to be 1031 feet thick. These measurements would bi"ing these foot- 
marks about 700 feet below the surface of the old red sandstone. 

A mass of coal plants exists immediately on the northern face (upper-) of the 
heavy conglomei-ate, here tilted ten degrees over the vertical, and forming the crest 
or "back-bone" of Sharp Mountain. This conglomerate mass is about 150 feet thick 
at the western side of the road below Pottsville. On the same road-side, about 1735 
feet from these coal plants (south and directly across the stratification), is the face 
of the rock tilted slightly over the vertical and facing to the north. It is proper to 
state that the limestone of the old red sandstone exists here, about 2 feet thick, and 
underlies these "footmarks 65 feet." 



On a New Species of Labyrintkodon from the New Red Sandstone of War' 
wickshire. By G. Lloyd, M.D., F.G.S. 

After stating the unfrequent occurrence of the remains of this extinct genus of 
reptiles, more especially of other parts of the body than of the bead, and having shown 



TRANSACTIONS OP THE SECTIONS. 5^ 

that on comparison with the remains of other species ah-eady described there were good 
grounds for assigning to the fossil referred to, and illustrated to the Section by a litho- 
graphic drawing, the rank of a new species, to which he proposed to apply the name 
Bucklandi, the author proceeded briefly to point out the osteologicai features of the 
fossil. The specimen was described as consisting of tlie internal surface of the 
greater part of the bones of the cranium, presenting both orbits entire, the nasal 
aperture somewhat mutilated, and about twenty more or less perfect teeth in the su- 
perior maxillary bone of one side, and also preserving, either by the presence of bone 
or by impressions left of absent bones, the general configuration of the skull, the di- 
mensions of which were about 11^ inches from the termination of the premandibular 
to the extremity of the projecting condyles of the occipital bone, and about 9 inches 
from the outer edge of one temporal bone to that of the other. The general consoli- 
dation of the bones of the cranium, especially of those forming the orbits, was con- 
trasted with the comparative loosely constructed skull of modern Batrachians ; and 
the projecting condyles of the occiput were pointed out as highly characteristic of that 
family. The teeth presented the usual characters of the genus ; and the position of 
the nostril, in conjunction with the other osteologicai peculiarities, confirmed the com- 
pound nature and amphibian habits of this reptile. The fossil described was recently 
discovered in the Bunter-sandstein. 



Note on the Genus Siphonotreta, with a Description of a New Species. By 
John Morris, F.G.S. {Communicated by Sir R. I. Murchison.) 

Among the numerous interesting fossils collected by Mr. John Gray from the Wen- 
lock limestone and shale in the vicinity of Dudley, is a form which I am inclined to 
consider belongs to Siphonotreta (de Verneuil), a genus of Brachiopoda, hitherto con- 
sidered peculiar to the Silurian formations of Russia. 

The genus having been previously unnoticed in this country, and presenting some 
peculiarities both as regards the structure of the shell and the mode of attachment, it 
may not be uninteresting to offer a few general remarks on the subject; more especially 
as this shell, and some apparently allied forms, have been lately made the subject of a 
special notice by Dr. Kutorga of St. Petersburg. In this memoir* Dr. Kutorgahas 
grouped together in one family (the Siphonotretese) four genera, Siphonotreta, Schi- 
zotreta, Acrotreta, and Aulonotreta, which scarcely present any character in common, 
and have been in part considered by preceding authors as belonging to different 
groups or distinct subfamilies of the Brachiopoda. 

Of the above-mentioned generic forms, two of them have been known for about 
twenty years. One of them, remarkable for the immense abundance with which it 
occurs in the lower Silurian grits of the north of Russia, its broken fragments disse- 
minated in the plane of stratification, giving to the rock a micaceous appearance, was 
first made known (1829) as a peculiar genus by Prof. Eichwaldf, under the name of 
Obolus {Aulonotreta, Kut.) ; about the same period (1830), Pander J gave the name 
Ungula to this fossil, and which L. von Buch§ considered to be an Orthis. The other 
form was also first noticed by Prof. Eichwald in 1829 as a Crania [C. sulcata, C. un- 
guiculata), which he afterwards (1843) placed under Terehralula\\ ; subsequently how- 
ever M. de Verneuil, in the second volume of the great work on Russia ^, after a careful 
examination of these fossils, clearly recognized the differences which separated them 
from Crania and Terehratula, and gave them the very characteristic name of Sipho- 
notreta, describing two species, S. unguiculata and S. verrucosa. 

Since the publication of the work on Russia, four additional species of the latter 
genus have rewarded the researches of Hern. v. Volborth and other Russian geolo- 
gists, and which are fully described, as well as those previously known, in the mono- 
graph by Dr. Kutorga above alluded to, and from which is extracted the following 
synopsis of the principal characters of the genera in the family. 

* Uber die Siphonotreteae, von Dr. S. Kutorga, Verhandlungen der Kaiserlichen Minera- 
logischen Gesselschaft fiir das Jahr 1847, p. 250. 
t Zoologia Specialis, 1829, vol. i. p. 274. 
J Beitrage zur Geognosie der Russischen Reichs, 1830. 
§ Beitrage zur Bestimmung der Gebirgsformationen Russland, 1840. 
II Beitragen zur Kentniss des Russ. Reichs, 1843. 
if Russia and the Ural Mountains, 1845, vol. ii. p. 286. 



58 REPORT — 1849. 

SiPHONOTRETE^, Kutorgu. 
A. With a tubular closed sipho. 

a. The external siphonal opening passes from the apex towards the anterior 
margin. 

1 . Siphonotrcta, De Verneuil. 

b. The siphonal opening is directed from the apex towards the dorsal margin. 

2. Schizotreta, Kutorga (Orbiculoidea, D'Orb.). 

Opening narrow, slit-like ; no area, nor mark of deltidium. 

3. Acrotreta, Kutorga. 

Opening elongated oval; area triangular and flattened, with a deltidium-like 
furrow. 

B. With a furrow-like sipho, opened on the whole hinge plain. 

4. Aulonotreta, Kutorga {Gboliis, Eichw. ; Ungula, Pander). 

The author adds a series of critical remarks on the above groups, noticing some 
peculiarities of their geographical and geological position, and concludes bj' charac- 
terizing the new species of Siphonotreta. 

SiPHONOTRETA? ANGLICA. 

Shell of a rather oval form, depressed, marked by fine lines of growth ; surface mi- 
nutely but concentrically reticulated, reticulation regular with quadrangular areolae, 
and covered with many slender linear tubular spines or their bases, somewhat quin- 
cuncially arranged ; spines smooth, dilated at the base, a little above which they re- 
main of nearly uniform size throughout, and are regularly and transversely sulcated 
or contracted, giving the spines a beaded or jointed appeai-ance. 

The generarform of this shell and quincuncial arrangement of the spines resemble 
S. aciileata, Kutorga ; but as that author does not figure or allude to any reticulated 
structure or the moniliform spines*, this is considered to be distinct; unfortunately the 
specimen is compressed, so that all the characters are not fully shown. 



On the 3Ietamorphosis of certain Trilobites as recently discovered by M. Bar- 
rande. {Communicated by Sir Roderick Impey Murchison.) 

Sir Roderick Murchison brought before the Section the important discover}' made 
by M. Barrande, of the metamorphosis of Trilobites, as exhibited in a series of forms 
apparently very distinct, but which have been shovsrn by that author to belong to the 
one species Sao hirsufa (Barr.). Referring in the first instance to the extraordinary 
number of species of Trilobites recently discovered in the palaeozoic rocks of Bo- 
hemia, whether as compared with the small number hitherto known in that tract, 
or the whole quantity described in other parts of the world. Sir Roderick explained 
how with untiring zeal and ability, and at considerable cost and labour, M. Bar- 
rande had been the real agent in opening out this rich field, and how by a long and 
careful analysis of all its organic remains he had shown that it is essentially of Silu- 
rian age. In anticipation of a great work by M. Barrande (the ' Silurian Rocks of 
Bohemia'), in which the necessary proofs will be given, and containing among 
numerous other illustrations 40 plates of Trilobites only. Sir Roderick communicated 
the following extract of a letter from that author : — 

"The fact, which is made intelligible by the plate of drawings annexedf, relates 
to a species which I have named Sao hirsufa, of which I have verified the gradual 
development from the embryonic to the adult state. I have been able to discover 
twenty successive stages in this progress, which took place after development from 
the egg, as is observed in some of our modern crustaceans. The first stage is marked 
by a disc two-thirds of a millimetre in diameter, of which the head only occupies 
the whole of the trilobed surface. In the second stage the thorax appears in a 
rudimentary state, and it increases in the following stages by the successive additioa 

* The moniliform character of the spines may not be peculiar to this species, but will pro- 
bably be found to belong to the wliole genus, when the spines are carefully examined by a 
higher power than that used by Dr. Kutorga. 

t Of these an enlarged diagram by Mr. Salter was exhibited. 



TRANSACTIONS OF THE SECTIONS. 59 

each time of a ring, until the thorax has thus acquired seventeen free segments, and 
the pygtdium two anchylosed segments, in all nineteen, which constitute the adult 
age. During the course of this evolution the form of the different parts of the body 
is developed in so continuous a manner, that in tracing the successive stages there 
is no sort of ' hiatus.' Towards the sixth stage four isolated grains are observed 
on each side of the glabella. I name ' principal grain ' that which is nearest to the 
axis, and ' primitive grains ' the three other and smaller grains, which are arranged 
in a convex band towards the interior. Now, these four grains are persistent in 
all the following stages, both in their relative size and reciprocal position, with a 
constancy and regularity which alone might suffice to estabUsh the specific identity 
of all these forms. The principal grain is also recognizable upon the adult, but at 
that age the three primitive grains become merged or lost amidst a crowd of other 
grains which accumulate around them. They all terminate in assuming a conical 
form, i. e. they become spines. [The figures show the details.] 

" Three other species have offered to me an analogous development, but with fewer 
intermediary stages between the extremes. These are the Trinucleus ornatus (Stern- 
berg), Arioriius ceticephalus (Barr.), and Arethusina Konincki (Barr.). 

" The embryonic evolution out of the egg took place then in species or isolated 
genera among the trilobites of the Silurian epoch, just as among modern crustaceans. 
That which is remarkable is, that two of these four species belong to my lowest or 
primitive fauna, or to my band C, or the schists of Skrey, viz. Sao hirsuta and Ari- 
onim ceticephalus. You know that the Trinucleus ornatus characterizes my band D, 
or your Caradoc sandstone * ; and lastly, the Arethusina KonincJci is found exclusively 
at the base of my inferior limestone E, which occupies the place of your Wenlock 
formation. In the three other superior bands of my upper division of the Silurian 
system, no trilobite has offered to me a trace of a similar evolution. These all 
appear to be born with the complete number of thoracic segments, but not with all 
the articulations of the pygidium f. 

" I have thought that an acquaintance with this fact would be of some interest to 
you who first opened out the necropolis of trilobites. 

* M. Barrande does not consider, vfith Mr. Salter, that the Trinucleus Caractaci (Murch.) 
is the same species as the Tr'mucleus ornatus (Sternb.). 

t The comments made by the eminent naturalist M. Milne-Edwards, Member of the Aca- 
demy of Sciences in Paris, on this communication, must have so much weight, that a deviation 
is made from the ordinary practice in giving this abstract of them in a note. — " Prof. Milne- 
Edwards remarked that this discovery was equally interesting to the zoologist and physiolo- 
gist. Metamorphoses like those of the insect and tadpole were formerly supposed to be ex- 
ceptions to the ordinary rule, until the researches of Harvey showed, that the chick in the egg 
underwent changes quite as extensive and remarkable. It now appears to be a law of nature, 
that animals are more alike as they are observed at a period nearer their embryonic state ; 
and it is of the highest consideration in zoology to show, through what stages animals pass 
before arriving at their adult form. The zoological affinities of the trilobites were long a 
matter of dispute. They were first supposed to be Chitons, until Alexander Brongniart 
showed they were true crustaceans. But the crustacean forms are very varied, and it has 
been held uncertain whether the trilobites were allied to certain Isopoda, sc. Oniscus, or, as 
Mr. Thompson suggests, to Apus. Barrande's observations confirm the views of Mr. Thomp- 
son. The Isopods are born almost with the same form which they retain through life ; but 
the Apus quits the egg in an imperfect state, having but few of the segments which consti- 
tute the body of the adult. In the young Sao the number of thoracic segments continually 
increased until the animal was adult; and to each of these (though no traces are now seen) 
legs were certainly affixed, not like the hard legs of insects adapted to terrestrial movement, 
but soft and membranous like those of Apus, for swimming in the water. The cephalic 
shield, which in the youngest stage of Sao formed the whole animal, constitutes but a small 
portion of the adult ; and the amount of change exhibited in successive stages of development 
is so great, that it would be no wonder if zoologists should have built up upon it numerous 
species and even several genera. The rule which obtains now, that animals belonging to the 
same zoological type, though much differing in the adult, lose those differences in states ap- 
proaching their embryonic condition, is seen even in the remains of animals which perished 
in the most remote epochs ; and thus the tenants of the Silurian seas furnish arguments 
hitherto afforded by the study of living animals alone." 



60 REPORT — 1849. 

" How many times, in describing my species, do I think of your assertion, which 
the facts have so gloriously justified, ' that the Silurian system is the great centre 
of the creation of trilobites ' ! At that early epoch Bohemia seems indeed to have 
had the privilege of uniting an immense variety and multitude of these crustaceans ; 
for the number of my species already exceeds 200. If you think this account of the 
metamorphosis of a trilobite of sufficient importance, announce it in any form you 
please to the British Association for the Advancement of Science. 

"J. Barrande.'' 

On the Distribution of Gold Ore in the Crust and on the Surface of the Earth. 
By Sir Roderick Impey Murchison, G.C.S., F.R.S. kc 

The recent discovery of considerable quantities of gold ore in California having 
excited the public mind, and led to some conclusions which he esteemed lobe exagge- 
rated, the author took this occasion of the meeting of the British Association to bring 
forward the whole subject of the distribution of gold ore over the surface of the 
earth, not merely to develope his own views and those of others, but also to elicit by 
discussion, the knowledge of the assembled geologists, mineralogists, miners and statists. 
An enlarged Mercator's projection of the world was exhibited, on which all the leading 
ridges which had afforded gold ore in times past or present, were marked, as taken in a 
great part from a general sketch-map by M. Adolphe Erman of Berlin, the explorer 
of Siberia and Kamschatka, which is appended to a geographical and mineralogical 
description of California by M. Hoppe and himself, as inserted in the ' Archiv fiir 
Wissenschaftliche Kunde von Russland' (7 band, 4 heft). 

Referring to the works of Humboldt and Rose on the Ural Mountains, as well as to 
those of Helmersen and Hoffman, the former of whom constructed some time since a 
map of all the gold tracts of Siberia, and also citing the other contributions of M. 
Adolphe Erman on this head, Sir Roderick gave a condensed view of his own obser- 
vations on the gold regions of the Ural Mountains. His exploration of that chain, in 
company with his associates M. de Verneuil and Count Keyserling, led him to form 
the opinion, that great and rich gold veins had alone been produced in the oldest 
formations, and chiefly where they have been highly metamorphosed by the intrusion 
of igneous rocks; in other words, that wherever clay-slates, old limestones, and 
greywacke sandstones (whether azoic or of Silurian, Devonian and Carboniferous age), 
had been penetrated by greenstone, porphyry, syenite, granite or serpentine, and were 
consequently in a more or less metamorphic or crystalline condition, there auriferous 
quartzose veinstones most occur, containing gold ore diffused in grains, leaves, lumps, 
and irregular filaments. Every discovery in the auriferous regions of Siberia and 
America, as well as all the workings in the Old World in past times, confirm this view, 
and prove it to be a geological constant, that the azoic and palaeozoic rocks, when 
metamorphosed, are the only great repositories of gold ore. The minute quantities 
of auriferous pyrites and gold which have been detected in the secondary and 
younger deposits do not interfere with this generalization. 

To the general view of Baron von Humboldt, that the richest gold deposits are those 
which are derived from ridges having a meridian direction, M. Adolphe Erman is de- 
cidedly opposed ; but Sir Roderick is of opinion, that a much greater quantity of gold 
ore has been obtained from chains having a nearer relation to N. and S. than from 
those approaching to equatorial or E. and W. directions, due perhaps to the general 
form of the chief masses of land and the prevailing strike of the palaeozoic rocks. He 
next pointed out an error into which some persons had fallen, of supposing that the 
chief Uralian mines were worked underground ; the only small subterranean work being 
one near Ekaterinburg, which affords a very slight profit. All the rich mines along that 
meridian chain, throughout 8° of N. latitude, are simply diggings and washings which 
are made in the detritus or shingle accumulated on the slopes of the ridges and in the 
adjacent valleys, and with one small exception are all upon the eastern or Siberian side. 
Tliis phaenomenon in the Ural Mountains is a necessary result of their structure ; the 
older and more crystalline formations through which the eruptive rocks have risen 
constituting chiefly the crest and eastern slopes of the chain, whilst the western slopes 
are occupied by deposits of younger or Permian age. As the conglomerates and de- 



TRANSACTIONS OF THE SECTIONS. 61 

trihis of the latter deposits contain no traces of gold, though they abonnd in copper 
ores, it was pointed out by the author in his work on Russia, that the auriferous 
veins were there posterior to those of iron and copper, and must have been produced 
after the accumulation of the Permian system. 

Exhibiting maps, sections and views of the Ural Mountains, formerly prepared by 
him, and referring to the description of California by Erman and others, he entered 
upon a comparison between the two counti'ies, and showed that there were great coinci- 
dences of mineralogical structure in both, and that with these constants the same 
results obtained in America as in the Ural ; the chief distinction consisting in the 
apparently larger proportion of gold in the detritus of the newly-discovered deposits of 
California than in those of the Ural. He contended, however, that no very large tract 
of California would be found to be as uniformly auriferous as the banks and slopes of 
the upper tributaries of the Sacramento. That gold ore has been found in certain 
localities along the western slope of the Sierra Nevada is admitted, but its conti- 
nuity as well as the breadth of the deposit have yet to be ascertained. 

And here the author took some pains to indicate the distinction between all such 
surface operations as those of Siberia, California, and the Brazils, and those works 
in which, besides the ores of silver, copper, &c., gold also had been extracted from 
veins in the solid or parent rock ; the latter operation being very seldom remunera- 
tive. Adverting to the fact, that in the Ural Mountains the veinstones "in situ" (in 
this case little or no admixture with other ore exists) have proved very slightly remu- 
nerative when worked further downwards, he glanced at an opinion of Humboldt, who 
looking to the great lumps or " pepites " occasionally found in the surface rubbish, sup- 
posed that there may have been some connection between the production of gold and 
the atmosphere ; since judging from these specimens, it was from the superficial extre- 
mity of these quartz veins that the richest bunches of gold must have been derived ; the 
veinstones when followed downwards having invariably proved either sterile or very 
slightly productive. 

The author carefully distinguishes the major part of the auriferous detritus from 
modern alluvia, and shows that it has been the result of former and more powerful 
causes of degradation than those now in operation — causes which distributed coarse 
shingle, blocks and sand, and which wearing away all the associated schists and 
the most oxidizable ores, left only the harder rocks, particularly the quartz veins, 
together with the harder and nobler metals gold and platinum. The existing rivers 
have had little more to do with this phEenomenon than that in mountainous tracts ; 
and where they have a rapid descent, they have occasionally laid bare the edge of the 
previously-formed and water-worn gold accumulations. By this observation it is not 
meant to deny, that where existing streams flow directly from rocks "in situ" which 
are now impregnated with gold, a little auriferous detritus must not naturally be 
washed down, but simply to prevent the student who may refer to detailed maps of 
gold tracts from imagining that the rivers are auriferous, except where they derive 
that quality from the wearing away and breaking down of the mixed materials 
which constitute their ancient banks. In a word, British geologists may be assured 
that gold shingle and sand have been accumulated just in the same manner as the 
former great drifts of their own country, whether general or local, in which bones of 
the fossil elephant, rhinoceros, and other extinct quadrupeds occur. 

Having terminated his account of the geological constants which accompany gold 
mines in Europe, Asia and America, Sir Roderick then traced the history of gold and 
its development, as known to the ancients and our ancestors of the middle ages. He 
showed that in all regions where the above-mentioned palaeozoic, crystalline and 
eruptive rocks occuiTed, gold had been found in greater or less quantities, and that 
just in proportion to the time a country had been civilized, the extraction of the pre- 
cious metal had diminished ; so that in many tracts, as in Bohemia, where gold had 
formerly prevailed to a great extent, it had been worked out and the mines forgotten. 
Briefly alluding to the examples at home of gold-works in Wales under the Romans, 
where Silurian rocks are pierced by trap, and contain pyritous veinstones as described 
by himself*, and to the former gold of Scotland and Ireland in similar rocks, its oc- 
casional discovery still in the detritus of the county of Wicklow, and its diffusion in 

* Silurian System, p. 367. 



62^ REPORT— 1849. 

some of the oldest Silurian strata of Merionethshire, he particularly dwelt on the con- 
tinental ti'acts formerly so rich, as cited by Strabo, all of which (with the exception 
of the North Ural or countiy of the Arimaspes*, from whence, as Humboldt believes, 
the Scythian ores came) had been exhausted and were no longer gold-bearing di- 
stricts. This circumstance is explained by the Scythian or Uralian gold having re- 
mained unknown from the classical age until this century. So completely ignorant 
were the modern Russians of the existence of gold in the Ural Mountains, or that 
they had in their hands the country which supplied so much gold to Greece and 
Rome, that excellent German miners had long worked the iron and copper mines of 
that chain before any gold was discovered. Even then gold was worked from a solid 
veinstone for some time before the accidental discovery of gold ore in the ancient al- 
luvium or drift led to the superficial diggings, which produced at an infinitely less 
expense the present produce. All the energy however displayed by the Russian 
miners has failed to augment the amount of Ui-alian gold much beyond half a million 
sterling, and as the period is arriving when the local depressions or basins of aurife- 
rous detritus of that region will be successively washed out, the Ural will then re- 
semble many other countries in possessing actual mines of iron and copper, but a 
history merely of its gold. Russia, however, has also the golden key of all eastern 
Siberia, in which various offsets from the Altai 'chain (chiefly those which separate 
the rivers Lena, Jenisei, &c., or stretch along the shores of the Baikal lake) have 
proved so very productive in their gravel, that for some years they have afforded the 
enormous annual supply of upwards of three millions sterling, exclusive of the Ural. 

As in the Ural Mountains, so has it proved to be in South America. There, the 
Spaniards, notwithstanding their keen search for gold from the days of Columbus to the 
present time, made many works in the parent rock, but either never discovered its 
existence or neglected to work it in the gravel and sand of the valley of the Sacra- 
mento, which tract they left in quiet possession of the native Indians, It was only 
indeed by the recent accident of the breaking away of a bank of detritus by a mill 
race, that this region was opened out for the first time to the colonists of the Anglo- 
Saxon race. Wliat then is to be the value and duration of these Californian mines? 
On the point of absolute value the author does not venture to form an estimate in 
the absence of suflicient facts and statistical data ; but in regard to the duration of 
this mining ground, he speculates that granting it to be locally much richer than 
similarly constituted detritus in the Ural, still there is nothing to interfere with the 
belief, founded on the experience derived from all other auriferous tracts, including 
those of Bohemia so productive in the middle ages, that, with the activity and num- 
bers of the men now employed in the works, these deposits may in uo great length 
of time be exhausted. 

Judging from analogous facts, he is inclined to think, that the very great per-centage 
of gold ore in the gravel of the valleys of the Sacramento, indicates that the most 
valuable portions of the original veins have been ground down by former powerful 
denuding agencies ; and if the rule be allowed which obtains very generally in 
mining, that the richer the veins the less are they likely to be spread over a large 
mass of parent rock, so is he disposed to think, that it will only be in certain patches 
that very great wealth will be discovered, and hence that it would be very wrong to 
conclude, that because rich gold detritus has been discovered on the affluents of the 
Sacramento, in lat. 40°, and also on the river Colorado in lat. 34° 5', all the interme- 
diate tract of country should prove productive. Considering the vast addition in the 
few last years made to the European market by researches in Siberia, and seeing that 
such addition has produced no change in the value of gold as a standard, the author is 
of opinion (as far as the evidences allow him to judge), that the Californian discovery 
is not likely to produce any disturbance in the standard. At the same time he ex- 
presses his full agreement with M. Erman and others, that with the advancement of 
colonization in the central regions of North Asia, and other parts of the world 
where civilization has not yet extended, other gold tracts may be discovered, wherever 
the geological and lithological constants to which he has adverted occur; but neither 

* If the gold tracts of the Ural Mountains had been explored and continuously worked from 
the time of Herodotus, they would have been exhausted ages before their occupation by the 
Russians. — R. I. M. 



TRANSACTIONS OP THE SECTIONS. 63 

would this circumstance induce him to fear, that such discoveries (occurring probably 
at long intervals of time and for the most part in countries at enormous distances 
from the means of transport) will much more than compensate for the wear and tear 
of the precious metal, and the wants of a rapidly increasing population. 

Sir Roderick then briefly alluded to the erroneous opinion of old authors, that the 
origin of gold had any reference to hot or equatorial climates, as testified by the abun- 
dance of ore in Siberia, even up to 67° N. lat., and cited a table of M. Erman, which 
showed, that by far the greatest quantity occurred in northern latitudes, there being 
every probability, that much more of this ore may be detected in the northern pro- 
longation of the American chains and in the frozen regions of Russian America, just 
as it had been discovered in ridges of the north-east of Siberia and even near to Kam- 
schatka. 

He reminded his auditors, that in considering the composition of the chief meri- 
dian ridge of Australia and its parallels, he had foretold that gold would be found 
in them ; and he stated that in the last year a resident in Sydney (Mr. Smith), 
who had read what he had written and spoken on this point, had sent him specimens 
of gold ore found in the Blue Mountains, whilst from another source (Mr. Phillips) 
he had learned, that the parallel N. and S. ridge in the Adelaide region, which had 
yielded so much copper, had also given more undoubted signs of gold ore. The 
operatien of the English laws of royalty had induced Sir Roderick Murchison to re- 
present to Her Majesty's Secretary of State, that no colonists would bestir themselves 
in gold mining if some authoritative declaration on the subject were not made. The 
auriferous lines in Australia were marked in the general map. 

In support of his general views, he called for the evidence of Professor William 
Rogers of Philadelphia, whose beautiful map of the Appalachian or Alleghany chain 
was exhibited ; and he also fortified his inductions respecting the chief auriferous 
masses of Mexico and Peru by appeals to Colonel Colquhoun and Mr. Pentland, 
all these gentlemen being present. References were also made to an article by M. 
Michel Chevalier in the 'Revue des deux Mondes' (1847), on the silver and gold 
mines of the New World as compared with those of the Old World ; also to the work 
on the mines of Mexico by M. St. Clair Duport, to M. Duflot de Mofras, to Mac- 
culloch's ' Dictionary of Commerce,' and to Professor Ansted's ' Gold Seeker's 
Manual.' 

In conclusion, he specially directed attention to the distinctions between the two 
classes of gold-works, i. e. in the veinstones and in their debris, and showed, that 
in the present day as in the remotest periods, the simple digging into and washing 
of old alluvial accumulations, have invariably proved to be the great source of pro- 
duction ; whilst in works in the solid rock, on the contrary, the extraction of the gold 
from the silver alloy and other ores with which it is mixed up therein, and its sepa- 
ration from them, have proved so expensive, that to mine for gold as the Spaniards 
have done in South America, has frequently proved ruinous even to a proverb*. 



On the Fossil Geology of Cornwall. By Charles William Peach. 

The author commenced by noticing the extensive beds containing fish remains, 
which had been discovered since he communicated to the Section at Cork the few 
then found; that the beds enclosing these remains extend from near the Ranie Head, 
Whitsand Bay, to the west side of Fowey, and that they are in places abundant; 
Bellerophontes also are rather plentiful, but each appear to have lived and died in 
separate flocks, rarely being intermixed with each other; a very few Gasteropods 
{Loxonema) are mingled with them. The beds generally rise at high angles, and are 
intermingled with trappean and quartzose beds, the line of strike nearly east and 
west, with a southerly dip, and appear to have been in places greatly disturbed. 

Underlying these beds on the south side are a series of slaty, arenaceous and cal- 
careous ones, containing Corals, Crinoids, Shells, Orthoceratites, a few Goniatites and 
Trilobites, some of these very abundant. These beds are first seen on the east side of 

* The author expressed his regret at not being as yet acquainted with a geological work on 
California by the able American naturalist M. Dana, which had recently been announced. 



64 REPORT — 1849. 

Pencarra Point, and extend to beyond the Black Mead, St. Austel Ba)'. Outside these 
ave a series of hard quartzose rocks, commencing at the Cairn near Goran Haven, 
passing across to Caerhayes Beach, tlience to Gerrans Bay; these contain Corals and 
Crinoids very rare, Orthides, and other bivalves more plentifully, and Trilobites not 
uncommon : there are also at these places small beds of limestone, a large series of 
conglomerates, in which are rolled blocks of limestone filled with crinoids and Ortlio- 
ccratites ; these rocks are a little out of the general line of strike. On the north side 
of these fish-beds are a very extensive range of fossiliferous ones, resting conformably 
on them ; these may be traced from Whitsand Bay to St. Veep, and St. Winnow, and 
completely occupy the county via Bodmin, Liskeard, &c., to the sea on the north side. 
Although all the other organisms mentioned as occurring in the southern rocks are 
found in these, no traces of Trilobites have been noticed until reaching Bodmin ; and 
at Menheniott, a bed exists there containing thousands. The author had also found 
organic remains rather plentiful at St. Columbporth, and at Newquay in the North 
Channel ; at the latter place splendid Turbinolopsides, Crinoids, Trilobites, and a mag- 
nificent spine of an Onchus in clay-slates, associated with beds of impure limestone. 
He remarked upon the very few fish remains that agreed with those found in the 
old red sandstone (one good specimen of Asterolepis, the species selected by Mr. 
Hugh Miller to illustrate 'The Footprints of the Creator') and those described in 
the ' Silurian System.' He concluded by saying that when Sir H. Dela Beche made 
his survey of the county, only three or four places were known to be fossiliferous ; now 
three-fourths of the county had been proved to be so, and in many places abundant : 
he trusted the day was not far distant when a new section would be run through the 
county, and the age of the rocks settled. 



Notice of the Discovery of Beds of Keuper Sandstone containing Zoophytes in 
the Vicinity of Leicester. By John Plant. 

In this paper the author describes the position of certain marls in the new red sand- 
stone laid open by the cutting of the Leicester and Swannington railway, and the 
existence in them of markings in the sandstone which he refers to the genus Gorgonia. 
The sections show a thickness varying from 2 to 50 feet of superficial and detrital 
deposit, below which appear clays, marls, shaly marls and sandstones, offering a total 
thickness of about 200 feet, of which the first 150 feet contain masses and blocks, some 
of them weighing many tons, of the sienites, porphyries, and carboniferous limestone 
of Charnwood Forest and the neighbourhood. Amongst these are gray shaly sand- 
stones containing the fossils developed between two beds of red clay which thin and 
swell out very irregularly. Between the sandstones are bands of fine marl enveloping 
the bodies described by the author as the polypidoms of a coralline, and these occur 
in great profusion on the surfaces of nearly every band, the bands being also furrowed 
by other markings. The polypidoms lie confusedly and in all instances occur as sili- 
ceous casts, the delicate organization of the cells being obliterated. Associated with 
them at times are thickly-set small granular concretions, giving the surface the appear- 
ance of shagreen. 

The strata containing the fossils are considered to represent the keuper sandstone, 
both by their similar character and their distance from the lias. The author sug- 
gests for these fossil markings the name Gorgonia Keuperi. 



On the Discovery of a Living Representative of a small Group of Fossil Volutes 
occurring in the Tertiary Rocks. By Lovell Reeve, F.L.S. 

In the Eocene portion of the tertiary series a small group of Volutes occurs, distin- 
guished by a peculiarity of form and sculpture which is not found in any living species 
collected hitherto. The well-known Valuta lima of the British tertiary strata may be 
regarded as the type of this group ; but there are other fossil species of the group which 
has been arranged as a subgenus by Mr. Swainson, luider the title Volutilithes. 
During the late expedition of H.M.S. Samarang, a single living example of this type, 



TRANSACTIONS OF THE SECTIONS. 65 

very closely and elaborately sculptured, and encircled by two or three coloured bands, 
was dredged by Sir Edward Belcher oflF the Cape of Good Hope, from a bank of 
dead shells, corallines, &c., at the depth of 132 fathoms. 

All the species of Valuta hitherto known in a recent state are of comparatively solid 
stnicture, characterized by a copious deposit of enamel on the body whorl on reaching 
maturity, and none exhibit any detail of sculpture beyond tliat of longitudinal ribs. 
The species under consideration is not identical with any of the tertiary species, but 
of the same type more minutely latticed, similarly coronated, so to speak, and with a 
similar channeled excavation round the spire. 

It is proposed to name it Voluta ahyssicola, and it will be described and figured in 
the Mollusca of the Voyage of the Samarang. 



Prof. W. B. Rogers exhibited the State Survey of Virginia, geologically coloured, 
and gave a general sketch of the structure of the country, with especial reference to the 
Faults in the Alleghanies. The State of Virginia comprises an area of 6(),000 square 
miles, containing four distinct physical and geological districts : — 1 st, the Tertiary plain 
on the Atlantic; 2ndly, the rising ground consisting of gneiss, mica-slate and other 
primitive rocks, which lies between the coast plain and the Alleghanies, with the 
oolitic coal-field of Richmond occupying a depression on its surface ; 3rdly, the Alle- 
ghany mountains ; and 4thly, the great western coal-field. The Alleghanies consist of 
numerous parallel ridges of palaeozoic rocks, ranging north-east and south-west, sepa- 
rated from the primitive region by the " Blue ridge," a tract of igneous and highly 
altered rocks, which may be regarded as the igneous axis of the State. The anti- 
clinal ridges of the Alleghanies all lean to the westward ; and this want of symmetry 
increases towards the "Blue ridge," until the strata forming the western flanks of 
each ridge are completely inverted, and dip under those on the eastei*n side ; these 
great foldings and inversions of the strata are frequently attended by enormous faults, 
the western side of a ridge being absolutely engulphed and the eastern over-riding 
it ; in these cases the Lower Silurian rocks sometimes rest on the inverted carboni- 
ferous limestone, and even on the conglomerates of the coal-measures : the displace- 
ment of the strata must amount in many instances to 10,000 feet; but if a fault is 
traced to a great distance either way, it is found to diminish gradually and terminate 
in a mere flexure of the strata; the length of the faults is sometimes more than 100 
miles. Prof, Rogers then mentioned the occurrence of workable anthracite below the 
carboniferous limestone of the Alleghanies. In conclusion, he stated that during a 
recent tour in the Alps he had observed a general conformity in the structure of those 
mountains with the law of flexures exhibited in the Alleghanies; that is to say, the 
greatest dip of every anticlinal and synclinal was on the side furthest removed from 
the axis of disturbance : so that the general direction of the ridges and the curvature 
of the strata would now afibrd indications of the direction of the dynamic agency 
by which those flexures were produced. 

On the Age of the Saurians named Thecodontosaurus and Palseosaurus. 
By William Sanders, F.G.S. 

The remains of these animals were discovered in the year 1835 by Dr. Riley and 
Mr. Stutchbury, who state that the dolomitic conglomerate in which they were im- 
bedded forms the base of the new red sandstone, adopting the views announced by 
Dr, Buckland and Mr. Conybeare, in their Memoir of the Bristol Coal District. 
This memoir was published in 1822, accompanied by a map and sections, which re- 
present distinctly the conglomerate rocks as constituting the lower division of the new 
red sandstone. The age thus assigned to these fossils was adopted by all geologists ; 
it is so described in the best elementary works, and enters into the general statement 
made by Professor Owen in his Report on Fossil Reptiles. The Ordnance maps and 
sections present no alteration in this respect ; they likewise represent the conglo- 
merate as completely subjacent to the later new red. 

Nevertheless the elaborate essay of Sir Henry De la Beche ' On the Formation of 
Rocks in South Wales and South-western England,' in the first volume of Reports of 
the Geological Survey, contains such a description of the new red sandstone beds as 
to lead the reader to concur with him in believing, that such conglomerates and 
limestones "may be of different dates," and that "the cause of their production con- 

1849. 5 



66 REPORT — 1849. 

tinuod up to, and included the base of the lias." The author of that essay also notices 
ceilain tranquil deposits of red clays and marls on the surface of the carboniferous 
rocks. After making these preliminary remarks, Mr. Sanders exhibited a map of the 
parish of St. George's, near the mouth of the Avon, and another map of the three 
parishes of Compton Martin and West and East [larptree, together with sections for 
the purpose of illustrating the fact, that the spaces coloured on the Ordnance map as 
conglomerate, are reallj' composed of several small tracts of conglomerate at different 
elevations, separated by larger tracts of tranquilly-deposited clays, marls, and sand- 
stones, similar in all respects to those which all concur in marking as the upper part 
of the new red sandstone. 

The evidences first, of a regular succession of strata on the sides of the hills ; se- 
condly, of the action of water at low levels ; and thirdly, of similar structure of rocks 
in the lower as in the upper parts, denoting similar depth of water, lead to the con- 
clusion that the land included in the Bristol district was, during the formation of such 
jjarts of the new red sandstone as are therein deposited, subjected to a gradual move- 
ment downwards, so that the waters first vouched the lowest parts of the hills, and 
then gradually ascended up to the highest point at which the conglomerates are 
found. This hypothesis is confirmed by the following facts: — On the northern side of 
the Mendip hills, at the height of 750 to 800 feet above mean sea level, there is depo- 
sited a conglomerate of the age of the white lias resting on lias strata tranquilly de- 
posited. On the tract of limestone northwards, called Broadfield Down, a conglomerate 
of similar age occurs at the height of about 550 feet. On the top of an isolated hill 
intermediate between these stations, at an elevation of 350 to 420 feet, occurs a lias 
conglomerate varying from 30 to 70 feet in thickness, not at the base of the lias, but 
likewise of the age of the white lias. This bed of conglomerate therefore descended 
from the shores on each side and crossed the valley at a lower level. The continuity 
of this bed renders highly probable the inference that the strata which are subjacent 
to this lias conglomerate on the hills, were also more or less continuous from shore 
to shore. 

If these views be correct, if the order of succession presented by the strata accu- 
mulated on the slopes of the hills correspond with the order of time at which they 
were formed, then a means is afforded of approximating to the age of any given bed 
resting on the older rocks, by reference to some other bed of known age at a limited 
distance from the hills and at a lower elevation, with which the given bed may have 
been in continuity. 

The dolomitic conglomerate containing the Saurians is situated about300 feet above 
mean sea level. The nearest horizontal formation is the base of the lias, which is 
at nearly the same height. The deposits of similar age at a distance of nearly one 
mile, are lower by about 100 feet, and similar strata at two miles from the limestone 
range are depressed to the extent of 150 feet. Combining these facts with the prin- 
ciples previously indicated, the Saurians, which form the subject of inquiry, may be 
pronounced to have lived during the time of the latest parts of the new red sandstone. 

Remarks in confirmation were made on the affinity of the Saurians with the Rhyn- 
chosaurus, and on the improbability that any part of the Permian system exists within 
the limits of the Bristol district. 

Mr. H. E. Strickland exhibited some specimens of vegetable remains in the keuper 
sandstone of Longdon, Worcestershire, where they were first noticed by the Dean 
of Westminster. These are for the most part fragmentary and obscure, but some of 
them appear referable to the genus Calaniites, and one specimen seems to be a J'^ollxia, 
a genus found in the new red sandstone of the continent, but only once before met 
■with in Britain. [This was in magnesian limestone of Northumberland, see Lindley, 
Fossil Flora, plate 195.] Tile state of preservation of these remains is remarkable; 
for instead of being black and carbonaceous, as is usual with fossil plants of so great 
antiquity, they are of a light brown colour, and highly elastic, resembling recent dead 
leaves. When viewed under the microscope these vegetable fragments exhibit the 
cellular texture in great perfection. The only other locality in Great Britain wlicre 
plants have been found in the keuper sandstone is at Ripple, three miles E. of Long- 
don, where Calamites occur, but the sandstone is not quarried there at present. The 
only animal remains found at these localities are small teeth and dorsal spines of the 
ffybodus. 



TRANSACTIONS OF THE SECTIONS. Bf' 

Mr. S. Stufclibury exhibited a large cylindrical bone found by Mr. Thompson of 
Aberdeen in the " Bone-bed " of Aust Cliff on ihe Severn, and presented to the Bristol 
Institution. The strata at this spot consists of the insect limestone, landscape marble, 
and bone-bed of the lias, resting on the marls of the new red sandstone system. But 
since the fish remains in the bone-bed belong to the Triassic type, it may be equally 
well to compare any reptilian remains found in it with those of the new red sand- 
stone. The present bone, though wanting both extremities, is two feet in length, and 
more than five inches in diameter at one end, where it is broken off" abruptly : it is 
unlike any bone of Chelonian or Enaliosaiu", but presents some i-esemblance to the 
long bones of small recent Batrachia, on which account Mr. Stutchbury considers it 
referable to the great Labyrinthodon of the new sandstone. 

On the Cause of the general Presence of Phosphorus in Strata and in all fertile 
Soils ; also on Pseudo-Coprolites, and the Conversion of the Contents of Sewers 
and Cesspools into Manure. By The Dean of Westminster, F.R.S. 

Since Liebig first suggested the application of fossil phosphates to the same pur- 
poses with recent bones and guano in agriculture, many inquiries have been directed 
to such localities as promised to afford a supply of bones, coprolites, &c. ; the bone- 
bed of the lias, exposed on the shores of the Severn, has not yet been worked, and 
will not repay the cost of working, but the red crag of Felixstow on the coast of Suffolk 
has afforded many thousands of tons of phosphoric pebbles, mixed with bones of whales 
and elephants and other large mammalia, and with flint pebbles, siliceous sand and 
crag-shells ; the phosphoric bodies show upon analysis a composition nearly identical 
with that of the true coprolite. The origin of the pseudo-coprolites in this remarkable 
deposit must be sought in a period antecedent to the crag, during which the London 
clay was in progress of formation, and when the muddy bed of the Eocene sea received 
daily accessions of phosphoric compoimds from the dead bodies and fteces of fishes 
and Molluscs which inhabited it. The remains of these creatures, decomposing in the 
mud, evolved ingredients which, combining with the surrounding sediment, became 
fixed in Septaria and smaller concretions, in deposits of siliceous sand no such com- 
binations could take place, and hence the barrenness of siliceous sands when converted 
into dry land. Phosphate of lime exists largely in all organized bodies, and is soluble 
slowly in water charged with carbonic acid : we may assume that all sea-water con- 
tains it; it exists in marine vegetables, and in herbivorous and carnivorous fishes and 
Molluscs. The combination of these phosphates with the earthy concretion not only 
purifies the water of the ocean and maintains it in a state adapted for the existence 
of living things; it serves also to form a continually increasing store of fertility against 
the time when the sea-beds shall be elevated and converted into corn-fields. While 
the crag was in progress, much of the London clay has been wasted by denudation, 
and its Septaria mixed with the shells and bones during the later period of the forma- 
tion of the crag. It is probable that the Septaria absorbed a still further quantity of 
phosphoric matter during their accumulation in the crag : it is possible, also, that 
the peroxide of iron which pervades these pebbles and bones in the crag may have 
added to the phosphate when all the ingredients were in a semi-fluid state at the 
bottom of the sea. The Dean then referred to the discovery by Mr. Payne of beds 
of pseudo-coprolites in the upper greensand of Farnham. Here sponges and other 
organic bodies appear to have served as recipients of the phosphates; the Kimme- 
ridge clay of Shotover Hill contains abundant casts of the air-chambers of Ammo- 
nites filled with marl, and containing 20 or 30 per cent, of phosphate of lime. Since 
all strata containing organic remains have more or less phosphoric compounds, these 
must also be present in the soils produced by their decomposition. Another large 
class of soils is produced from the decomposition of volcanic rocks and granite ; in 
these phosphoric matter is also present, either combined with lime (apatite), or as 
phosphate of iron, and here its presence is unconnected with organized remains. 
In Spain the apatite forms an immense vein in ancient schists; and every specimen 
brought home by Dr. Daubeny has a radiated and stalactitic structure, showing that 
they were deposited from water, which must have taken it up previously from other 
rocks. In conclusion, it was suggested that, since clay and marl and lime are em- 
ployed by Natvire to absorb the phosphoi'ic acid produced by the decomposition of 

5* 



68 REPORT — 1849. 

organized bodies at tlie bottom of ancient seas and lakes, so they might be applied 
artificially to deodorize and combine witlj the phosphates in the sewerage of large 
towns. 

On an original broad Sheet of Granite, interstratified among Slates with Grit 
Beds, betiveen Falmouth and Truro in Cornwall. By the Rev. D. Williams, 
F.G.S. 

This bed of granite is the only one of the kind ever seen by the author, who has 
traced it over a breadth of four miles by two. It varies in thickness from 4 feet 
,9 inches to 16 feet, and in dip from 15° to 40° ; in some places it undulates repeatedly 
with the slates, and in one there is a small shift in the slates, whilst the granite is 
only bent. 



ZOOLOGY AND BOTANY. 



On some Chatiges in the Male Flowers of Forty Days' Maize. 
By Robert A. C. Austen, F.R.S. 

The specimens I herewith send were taken from a crop of that variety of the Zea 
Mais which has recently been introduced into this country as the Forty Days' Maize : 
the seed was said to have been raised on the slopes of the Pyrenees, at an elevation 
of 3000 to 4000 feet, and th